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Sample records for cancer molecular mechanisms

  1. Molecular Mechanisms Underlying Psychological Stress and Cancer.

    Science.gov (United States)

    Shin, Kyeong Jin; Lee, Yu Jin; Yang, Yong Ryoul; Park, Seorim; Suh, Pann-Ghill; Follo, Matilde Yung; Cocco, Lucio; Ryu, Sung Ho

    2016-01-01

    Psychological stress is an emotion experienced when people are under mental pressure or encounter unexpected problems. Extreme or repetitive stress increases the risk of developing human disease, including cardiovascular disease (CVD), immune diseases, mental disorders, and cancer. Several studies have shown an association between psychological stress and cancer growth and metastasis in animal models and case studies of cancer patients. Stress induces the secretion of stress-related mediators, such as catecholamine, cortisol, and oxytocin, via the activation of the hypothalamic-pituitary-adrenocortical (HPA) axis or the sympathetic nervous system (SNS). These stress-related hormones and neurotransmitters adversely affect stress-induced tumor progression and cancer therapy. Catecholamine is the primary factor that influences tumor progression. It can regulate diverse cellular signaling pathways through adrenergic receptors (ADRs), which are expressed by several types of cancer cells. Activated ADRs enhance the proliferation and invasion abilities of cancer cells, alter cell activity in the tumor microenvironment, and regulate the interaction between cancer and its microenvironment to promote tumor progression. Additionally, other stress mediators, such as glucocorticoids and oxytocin, and their cognate receptors are involved in stress-induced cancer growth and metastasis. Here, we will review how each receptor-mediated signal cascade contributes to tumor initiation and progression and discuss how we can use these molecular mechanisms for cancer therapy.

  2. Molecular mechanisms of metastasis in prostate cancer

    Institute of Scientific and Technical Information of China (English)

    Noel W.Clarke; Claire A.Hart; Mick D.Brown

    2009-01-01

    Prostate cancer (PCa) preferentially metastasizes to the bone marrow stroma of the axial skeleton.This activity is the principal cause of PCa morbidity and mortality.The exact mechanism of PCa metastasis is currently unknown,although considerable progress has been made in determining the key players in this process.In this review,we present the current understanding of the molecular processes driving PCa metastasis to the bone.

  3. Molecular Mechanisms of Metastasis Suppression in Human Breast Cancer

    Science.gov (United States)

    2000-07-01

    and breast carcinoma metastasis, Wake Forest University Cancer Center, July 28 Molecular mechanisms controlling melanoma and breast carcinoma...Bowman Show, August 17 Molecular regulation of melanoma and breast carcinoma metastasis, Wake Forest University Cancer Center, July 28 Molecular...Institute, April 20, Pathology ofNeoplasia Cumberland Unit, American Cancer Society, April 19; Breast Cancer Research Ministerio de Sanidad y

  4. Molecular and neuroendocrine mechanisms of cancer cachexia.

    Science.gov (United States)

    Mendes, Maria Carolina S; Pimentel, Gustavo D; Costa, Felipe O; Carvalheira, José B C

    2015-09-01

    Cancer and its morbidities, such as cancer cachexia, constitute a major public health problem. Although cancer cachexia has afflicted humanity for centuries, its underlying multifactorial and complex physiopathology has hindered the understanding of its mechanism. During the last few decades we have witnessed a dramatic increase in the understanding of cancer cachexia pathophysiology. Anorexia and muscle and adipose tissue wasting are the main features of cancer cachexia. These apparently independent symptoms have humoral factors secreted by the tumor as a common cause. Importantly, the hypothalamus has emerged as an organ that senses the peripheral signals emanating from the tumoral environment, and not only elicits anorexia but also contributes to the development of muscle and adipose tissue loss. Herein, we review the roles of factors secreted by the tumor and its effects on the hypothalamus, muscle and adipose tissue, as well as highlighting the key targets that are being exploited for cancer cachexia treatment.

  5. Deciphering the Molecular Mechanisms of Breast Cancer

    Science.gov (United States)

    2005-03-01

    BRCA1 and BRCA2, by a Signalosome-like Subunit and its Role in DNA Repair. Molecular Cell 12; 1087-1099 (2003). Presentations/Abstracts...BRCA1 and BRCA2, by a Signalosome-like Subunit and its Role in DNA Repair. Molecular Cell 12; 1087-1099. APPENDICIES: CURRICULUM VITAE...Oncogenesis Program Member, Faculty Recruitment Committee Periodic Manuscript Reviews: Cell, Science, Molecular Cell , Molecular and Cellular

  6. Targeted therapies in epithelial ovarian cancer: Molecular mechanisms of action

    Institute of Scientific and Technical Information of China (English)

    Hiroaki; Itamochi

    2010-01-01

    Ovarian cancer is the leading cause of death in women with gynecological cancer. Most patients are diagnosed at an advanced stage and have a poor prognosis.Currently, surgical tumor debulking, followed by platinum- and taxane-based chemotherapy is the standard treatment for advanced ovarian cancer. However, these patients are at great risk of recurrence and emerging drug resistance. Therefore, novel treatment strategies are required to improve outcomes for women with advanced ovarian cancer. A variety of molecular targeted agents, the majority of which are monoclonal antibodies and small-molecule protein-kinase inhibitors, have been explored in the management of ovarian cancer. The targets of these agents include angiogenesis, the human epidermal growth factor receptor family, ubiquitinproteasome pathway, epigenetic modulators, poly(ADPribose) polymerase (PARP), and mammalian target of rapamycin (mTOR) signaling pathway, which are aberrant in tumor tissue. The antiangiogenic agent, bevacizumab, has been reported as the most effective targeted agent and should be included in the standard chemotherapeutic regimen for advanced ovarian cancer. PARP inhibitors, which are mainly used in breast and ovarian cancer susceptibility gene-mutated patients, and mTOR inhibitors are also attractive treatment strategies, either alone or combination with chemotherapy, for ovarian cancer. Understanding the tumor molecular biology and identification of predictive biomarkers are essential steps for selection of the best treatment strategies. This article reviews the molecular mechanisms of the most promising targeted agents that are under early phase clinical evaluation for ovarian cancer.

  7. Molecular mechanisms of TRAIL-induced apoptosis of cancer cells

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@Tumor Necrosis Factor-related Apoptosis-inducing Ligand (TRAIL) is a recently identified member of the tumor necrosis factor (TNF) family[1]. Numerous studies indicate that TRAIL can induce apoptosis of cancer cells but not of normal cells, pointing to the possibility of de-veloping TRAIL into a cancer drug[2-4]. This review will summary the molecular mechanisms of TRAIL-induced apoptosis and discuss the questions to be resolved in this field.

  8. Molecular Mechanism Underlying Lymphatic Metastasis in Pancreatic Cancer

    Directory of Open Access Journals (Sweden)

    Zhiwen Xiao

    2014-01-01

    Full Text Available As the most challenging human malignancies, pancreatic cancer is characterized by its insidious symptoms, low rate of surgical resection, high risk of local invasion, metastasis and recurrence, and overall dismal prognosis. Lymphatic metastasis, above all, is recognized as an early adverse event in progression of pancreatic cancer and has been described to be an independent poor prognostic factor. It should be noted that the occurrence of lymphatic metastasis is not a casual or stochastic but an ineluctable and designed event. Increasing evidences suggest that metastasis-initiating cells (MICs and the microenvironments may act as a double-reed style in this crime. However, the exact mechanisms on how they function synergistically for this dismal clinical course remain largely elusive. Therefore, a better understanding of its molecular and cellular mechanisms involved in pancreatic lymphatic metastasis is urgently required. In this review, we will summarize the latest advances on lymphatic metastasis in pancreatic cancer.

  9. The molecular mechanisms between metabolic syndrome and breast cancer.

    Science.gov (United States)

    Chen, Yi; Wen, Ya-yuan; Li, Zhi-rong; Luo, Dong-lin; Zhang, Xiao-hua

    2016-03-18

    Metabolic syndrome, which is extremely common in developed and some developing countries, is a clustering of at least three of five of the following medical conditions: abdominal obesity, elevated blood pressure, elevated fasting plasma glucose, high serum triglycerides, and low high-density lipoprotein levels. It has been proved that there is a strong association between metabolic syndrome and breast cancer. Metabolic syndrome could increase the risk of breast cancer and influence the prognosis of the breast cancer patients. Some characteristic of metabolic syndrome such as obesity and lack of physical exercise are all risk factors for developing breast cancer. The metabolic syndrome mainly include obesity, type 2 diabetes, hypercholesterolemia and nonalcoholic fatty liver disease, and each of them impacts the risk of breast cancer and the prognosis of the breast cancer patients in different ways. In this Review, we focus on recently uncovered aspects of the immunological and molecular mechanisms that are responsible for the development of this highly prevalent and serious disease. These studies bring new insight into the complex associations between metabolic syndrome and breast cancer and have led to the development of novel therapeutic strategies that might enable a personalized approach in the management of this disease.

  10. Advances in understanding the molecular mechanism of pancreatic cancer metastasis

    Institute of Scientific and Technical Information of China (English)

    Yong-Xing Du; Zi-Wen Liu; Lei You; Wen-Ming Wu; Yu-Pei Zhao

    2016-01-01

    BACKGROUND: Pancreatic cancer (PC) is usually diagnosed at the late-stage and therefore, has widespread metastasis and a very high mortality rate. The mechanisms underlying PC metastasis are not well understood. Recent advances in genomic sequencing have identiifed groups of gene mutations that affect PC metastasis, but studies elucidating their roles are lacking. The present review was to investigate the molecu-lar mechanisms of PC metastasis. DATA SOURCES: Relevant articles on PC metastasis were searched in MEDLINE via PubMed prior to April 2015. The search was limited in English publications. RESULTS: PC metastatic cascades are multi-factorial events including both intrinsic and extrinsic elements. This review highlights the most important genetic alterations and other mechanisms that account for PC invasion and metastasis, with particular regard to epithelial-mesenchymal transition, inlfammation, stress response, and circulating tumor cells. CONCLUSIONS: Analyses of relevant gene functions and signaling pathways are needed to establish the gene regula-tory network and to deifne the pivotal modulators. Another promising area of study is the genotyping and phenotyping of circulating tumor cells, which could lead to a new era of per-sonalized therapy by identifying speciifc markers and targets.

  11. Quantum Interactomics and Cancer Molecular Mechanisms: I. Report Outline

    CERN Document Server

    Baianu, I C

    2004-01-01

    Single cell interactomics in simpler organisms, as well as somatic cell interactomics in multicellular organisms, involve biomolecular interactions in complex signalling pathways that were recently represented in modular terms by quantum automata with ‘reversible behavior’ representing normal cell cycling and division. Other implications of such quantum automata, modular modeling of signaling pathways and cell differentiation during development are in the fields of neural plasticity and brain development leading to quantum-weave dynamic patterns and specific molecular processes underlying extensive memory, learning, anticipation mechanisms and the emergence of human consciousness during the early brain development in children. Cell interactomics is here represented for the first time as a mixture of ‘classical’ states that determine molecular dynamics subject to Boltzmann statistics and ‘steady-state’, metabolic (multi-stable) manifolds, together with ‘configuration’ spaces of metastable quant...

  12. Molecular mechanisms of chemopreventive phytochemicals against gastroenterological cancer development.

    Science.gov (United States)

    Chung, Min-Yu; Lim, Tae Gyu; Lee, Ki Won

    2013-02-21

    Cancer is one of the leading causes of death worldwide. Commonly used cancer treatments, including chemotherapy and radiation therapy, often have side effects and a complete cure is sometimes impossible. Therefore, prevention, suppression, and/or delaying the onset of the disease are important. The onset of gastroenterological cancers is closely associated with an individual's lifestyle. Thus, changing lifestyle, specifically the consumption of fruits and vegetables, can help to protect against the development of gastroenterological cancers. In particular, naturally occurring bioactive compounds, including curcumin, resveratrol, isothiocyanates, (-)-epigallocatechin gallate and sulforaphane, are regarded as promising chemopreventive agents. Hence, regular consumption of these natural bioactive compounds found in foods can contribute to prevention, suppression, and/or delay of gastroenterological cancer development. In this review, we will summarize natural phytochemicals possessing potential antioxidant and/or anti-inflammatory and anti-carcinogenic activities, which are exerted by regulating or targeting specific molecules against gastroenterological cancers, including esophageal, gastric and colon cancers.

  13. Molecular Mechanism by Which Retinoids Prevent Breast Cancer Development

    Science.gov (United States)

    2007-06-01

    clinicians to conquer this disease is to prevent the incidence, detect early and treat breast cancer with effective therapy resulting in long overall... biological functions such as embryogenesis, growth, differentiation, vision and reproduction (3-6). Retinoids also contain anti- proliferative...and are currently available to treat psoriasis , acne, photoaging, actinic keratosis or cancers such as acute promelocytic leukemia, cutaneous T-cell

  14. Molecular Mechanisms of Metastasis Suppression in Human Breast Cancer

    Science.gov (United States)

    1997-07-01

    mammary epithelial cells ( Stampfer , 1985). Protein from 184 cell lysate was kindly supplied by Dr. Bruce Lessey, University of North Carolina, Chapel...characterization of a spontaneously immortalized human breast epithelial cell line, MCF- 10. Cancer Res. 50, 6075-6086. Stampfer , M.R. (1985). Isolation and...Exp Cell Neri, Satya Murthy, Christopher Stackpole and Res, 204, 171-80. Janet Price who provided unpublished data, 15. Liotta LA, 1992, Cancer cell

  15. Molecular mechanisms linking adipokines to obesity-related colon cancer: focus on leptin.

    Science.gov (United States)

    Drew, Janice E

    2012-02-01

    Obesity is linked to increased risk of colon cancer, currently the third most common cancer. Consequently rising levels of obesity worldwide are likely to significantly impact on obesity-related colon cancers in the decades to come. Understanding the molecular mechanisms whereby obesity increases colon cancer risk is thus a focus for research to inform strategies to prevent the increasing trend in obesity-related cancers. This review will consider research on deregulation of adipokine signalling, a consequence of altered adipokine hormone secretion from excess adipose tissue, with a focus on leptin, which has been studied extensively as a potential mediator of obesity-related colon cancer. Numerous investigations using colon cell lines in vitro, in vivo studies in rodents and investigations of colon cancer patients illuminate the complexity of the interactions of leptin with colon tissues via leptin receptors expressed by the colon epithelium. Although evidence indicates a role for leptin in proliferation of colon epithelial cells in vitro, this has been contradicted by studies in rodent models. However, recent studies have indicated that leptin may influence inflammatory mediators linked with colon cancer and also promote cell growth dependent on genotype and is implicated in growth promotion of colon cancer cells. Studies in human cancer patients indicate that there may be different tumour sub-types with varying levels of leptin receptor expression, indicating the potential for leptin to induce variable responses in the different tumour types. These studies have provided insights into the complex interplay of adipokines with responsive tissues prone to obesity-related colon cancer. Deregulation of adipokine signalling via adipokine receptors located in the colon appears to be a significant factor in obesity-related colon cancer. Molecular profiling of colon tumours will be a useful tool in future strategies to characterise the influence that adipokines may have

  16. Molecular mechanisms linking thrombosis and angiogenesis in cancer.

    Science.gov (United States)

    Shoji, M; Abe, K; Nawroth, P P; Rickles, F R

    1997-02-01

    In this brief review, the authors concentrate on selected issues related to the newly described role of tissue factor (TF), the major activator of mammalian blood coagulation, as a regulator of angiogenesis and of tumor growth and metastasis. Previously, TF had been considered strictly as the primary activator of the coagulation cascade; however, it has recently been demonstrated that overexpression of the TF gene in murine tumor cells leads to increased transcription of the gene for vascular permeability factor/vascular endothelial growth factor (VEGF), a proangiogenic factor, and decreased transcription of the gene for thrombospondin (TSP), an antiangiogenic factor. Conversely, underexpression of TF leads to decreased VEGF and increased TSP transcription. When grown in mice and compared with low TF-producing tumor cells, high TF-producing tumor cells stimulate angiogenesis by approximately twofold. This effect of TF appears to be independent of its clot-promoting procoagulant activity (PCA) and suggests that TF regulates the angiogenic properties of tumor cells by altering the production of growth regulatory molecules (for example, VEGF) that can act on vascular endothelial cells (VECs). There is substantial preliminary evidence that the regulation of tumor angiogenesis can be mediated by TF via both fibrin clotting-dependent and fibrin clotting-independent mechanisms. (Trends Cardiovasc Med 1997;7:52-59). © 1997, Elsevier Science Inc.

  17. Dysregulation of Apoptotic Signaling in Cancer: Molecular Mechanisms and Therapeutic Opportunities

    Science.gov (United States)

    Plati, Jessica; Bucur, Octavian; Khosravi-Far, Roya

    2010-01-01

    Apoptosis is a tightly regulated cell suicide program that plays an essential role in the maintenance of tissue homeostasis by eliminating unnecessary or harmful cells. Defects in this native defense mechanism promote malignant transformation and frequently confer chemoresistance to transformed cells. Indeed, the evasion of apoptosis has been recognized as a hallmark of cancer. Given that multiple mechanisms function at many levels to orchestrate the regulation of apoptosis, a multitude of opportunities for apoptotic dysregulation are present within the intricate signaling network of cell. Several of the molecular mechanisms by which cancer cells are protected from apoptosis have been elucidated. These advances have facilitated the development of novel apoptosis-inducing agents that have demonstrated single-agent activity against various types of cancers cells and/or sensitized resistant cancer cells to conventional cytotoxic therapies. Herein, we will highlight several of the central modes of apoptotic dysregulation found in cancer. We will also discuss several therapeutic strategies that aim to reestablish the apoptotic response, and thereby eradicate cancer cells, including those that demonstrate resistance to traditional therapies. PMID:18459149

  18. Multiple Molecular and Cellular Mechanisms of Action of Lycopene in Cancer Inhibition

    Directory of Open Access Journals (Sweden)

    Cristina Trejo-Solís

    2013-01-01

    Full Text Available Epidemiological studies suggest that including fruits, vegetables, and whole grains in regular dietary intake might prevent and reverse cellular carcinogenesis, reducing the incidence of primary tumours. Bioactive components present in food can simultaneously modulate more than one carcinogenic process, including cancer metabolism, hormonal balance, transcriptional activity, cell-cycle control, apoptosis, inflammation, angiogenesis and metastasis. Some studies have shown an inverse correlation between a diet rich in fruits, vegetables, and carotenoids and a low incidence of different types of cancer. Lycopene, the predominant carotenoid found in tomatoes, exhibits a high antioxidant capacity and has been shown to prevent cancer, as evidenced by clinical trials and studies in cell culture and animal models. In vitro studies have shown that lycopene treatment can selectively arrest cell growth and induce apoptosis in cancer cells without affecting normal cells. In vivo studies have revealed that lycopene treatment inhibits tumour growth in the liver, lung, prostate, breast, and colon. Clinical studies have shown that lycopene protects against prostate cancer. One of the main challenges in cancer prevention is the integration of new molecular findings into clinical practice. Thus, the identification of molecular biomarkers associated with lycopene levels is essential for improving our understanding of the mechanisms underlying its antineoplastic activity.

  19. Multiple molecular and cellular mechanisms of action of lycopene in cancer inhibition.

    Science.gov (United States)

    Trejo-Solís, Cristina; Pedraza-Chaverrí, Jose; Torres-Ramos, Mónica; Jiménez-Farfán, Dolores; Cruz Salgado, Arturo; Serrano-García, Norma; Osorio-Rico, Laura; Sotelo, Julio

    2013-01-01

    Epidemiological studies suggest that including fruits, vegetables, and whole grains in regular dietary intake might prevent and reverse cellular carcinogenesis, reducing the incidence of primary tumours. Bioactive components present in food can simultaneously modulate more than one carcinogenic process, including cancer metabolism, hormonal balance, transcriptional activity, cell-cycle control, apoptosis, inflammation, angiogenesis and metastasis. Some studies have shown an inverse correlation between a diet rich in fruits, vegetables, and carotenoids and a low incidence of different types of cancer. Lycopene, the predominant carotenoid found in tomatoes, exhibits a high antioxidant capacity and has been shown to prevent cancer, as evidenced by clinical trials and studies in cell culture and animal models. In vitro studies have shown that lycopene treatment can selectively arrest cell growth and induce apoptosis in cancer cells without affecting normal cells. In vivo studies have revealed that lycopene treatment inhibits tumour growth in the liver, lung, prostate, breast, and colon. Clinical studies have shown that lycopene protects against prostate cancer. One of the main challenges in cancer prevention is the integration of new molecular findings into clinical practice. Thus, the identification of molecular biomarkers associated with lycopene levels is essential for improving our understanding of the mechanisms underlying its antineoplastic activity.

  20. Molecular mechanisms of anti-cancer action of garlic compounds in neuroblastoma.

    Science.gov (United States)

    Karmakar, Surajit; Choudhury, Subhasree Roy; Banik, Naren L; Ray, Swapan K

    2011-05-01

    The medicinal properties of garlic (Allium sativum) have been well known and widely used since historical times. Garlic compounds have received increasing attention during the last few years due to their cancer chemopreventive properties. The anti-cancer activity of garlic-derived organosulfur compounds (OSCs) are extensively reported in many cancers but only a few in the pediatric tumor neuroblastoma, which warrants exploration of new therapy for its management. There are some recent reports suggesting that garlic-derived OSCs cause cell cycle arrest, generate reactive oxygen species (ROS), activate stress kinases, and also stimulate the mitochondrial pathway for apoptosis in malignant neuroblastoma. The comprehensive mechanisms of anti-cancer action of OSCs still remain unclear and require more studies in neuroblastoma. This review is designed to highlight the molecular mechanisms of anti-cancer actions of garlic-derived OSCs in neuroblastoma and as well as in several other cancers. Further studies should be conducted to establish the clinical expediency of garlic-derived OSCs for treatment of malignant neuroblastoma in humans.

  1. Antiproliferative and Molecular Mechanism of Eugenol-Induced Apoptosis in Cancer Cells

    Directory of Open Access Journals (Sweden)

    Eko Supriyanto

    2012-05-01

    Full Text Available Phenolic phytochemicals are a broad class of nutraceuticals found in plants which have been extensively researched by scientists for their health-promoting potential. One such a compound which has been comprehensively used is eugenol (4-allyl-2-methoxyphenol, which is the active component of Syzigium aromaticum (cloves. Aromatic plants like nutmeg, basil, cinnamon and bay leaves also contain eugenol. Eugenol has a wide range of applications like perfumeries, flavorings, essential oils and in medicine as a local antiseptic and anesthetic. Increasing volumes of literature showed eugenol possesses antioxidant, antimutagenic, antigenotoxic, anti-inflammatory and anticancer properties. Molecular mechanism of eugenol-induced apoptosis in melanoma, skin tumors, osteosarcoma, leukemia, gastric and mast cells has been well documented. This review article will highlight the antiproliferative activity and molecular mechanism of the eugenol induced apoptosis against the cancer cells and animal models.

  2. Antitumor effects and molecular mechanisms of ponatinib on endometrial cancer cells harboring activating FGFR2 mutations.

    Science.gov (United States)

    Kim, Do-Hee; Kwak, Yeonui; Kim, Nam Doo; Sim, Taebo

    2016-01-01

    Aberrant mutational activation of FGFR2 is associated with endometrial cancers (ECs). AP24534 (ponatinib) currently undergoing clinical trials has been known to be an orally available multi-targeted tyrosine kinase inhibitor. Our biochemical kinase assay showed that AP24534 is potent against wild-type FGFR1-4 and 5 mutant FGFRs (V561M-FGFR1, N549H-FGFR2, K650E-FGFR3, G697C-FGFR3, N535K-FGFR4) and possesses the strongest kinase-inhibitory activity on N549H-FGFR2 (IC50 of 0.5 nM) among all FGFRs tested. We therefore investigated the effects of AP24534 on endometrial cancer cells harboring activating FGFR2 mutations and explored the underlying molecular mechanisms. AP24534 significantly inhibited the proliferation of endometrial cancer cells bearing activating FGFR2 mutations (N549K, K310R/N549K, S252W) and mainly induced G1/S cell cycle arrest leading to apoptosis. AP24534 also diminished the kinase activity of immunoprecipitated FGFR2 derived from MFE-296 and MFE-280 cells and reduced the phosphorylation of FGFR2 and FRS2 on MFE-296 and AN3CA cells. AP24534 caused substantial reductions in ERK phosphorylation, PLCγ signaling and STAT5 signal transduction on ECs bearing FGFR2 activating mutations. Akt signaling pathway was also deactivated by AP24534. AP24534 causes the chemotherapeutic effect through mainly the blockade of ERK, PLCγ and STAT5 signal transduction on ECs. Moreover, AP24534 inhibited migration and invasion of endometrial cancer cells with FGFR2 mutations. In addition, AP24534 significantly blocked anchorage-independent growth of endometrial cancer cells. We, for the first time, report the molecular mechanisms by which AP24534 exerts antitumor effects on ECs with FGFR2 activating mutations, which would provide mechanistic insight into ongoing clinical investigations of AP24534 for ECs.

  3. Molecular Mechanisms and Translational Therapies for Human Epidermal Receptor 2 Positive Breast Cancer

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    Quanxia Lv

    2016-12-01

    Full Text Available Breast cancer is the second leading cause of cancer death among women. Human epidermal receptor 2 (HER2 positive breast cancer (HER2+ BC is the most aggressive subtype of breast cancer, with poor prognosis and a high rate of recurrence. About one third of breast cancer is HER2+ BC with significantly high expression level of HER2 protein compared to other subtypes. Therefore, HER2 is an important biomarker and an ideal target for developing therapeutic strategies for the treatment HER2+ BC. In this review, HER2 structure and physiological and pathological roles in HER2+ BC are discussed. Two diagnostic tests, immunohistochemistry (IHC and fluorescent in situ hybridization (FISH, for evaluating HER2 expression levels are briefly introduced. The current mainstay targeted therapies for HER2+ BC include monoclonal antibodies, small molecule tyrosine kinase inhibitors, antibody–drug conjugates (ADC and other emerging anti-HER2 agents. In clinical practice, combination therapies are commonly adopted in order to achieve synergistic drug response. This review will help to better understand the molecular mechanism of HER2+ BC and further facilitate the development of more effective therapeutic strategies against HER2+ BC.

  4. The molecular mechanism of different sensitivity of breast cancer cell lines to TRAIL

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jindan; LIU Yanxin; LIU Shilian; ZHENG Dexian

    2004-01-01

    Although Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) selectively induces apoptosis of various cancer cells, some caner cell lines are resistant to TRAIL-induced cell death. To investigate the molecular mechanisms underlying TRAIL-resistance, two human breast cancer cell lines, MCF-7 (resistant to TRAIL) and MDA-MB-231 (sensitive to TRAIL), were used as a model system to analyze the different sensitivities to TRAIL cytotoxicity. PKCδ inhibitor rottlerin, but not MEK and ERK1/2 inhibitor U0126 nor PI3K inhibitor LY294002, was shown to enhance TRAIL-induced apoptosis in MCF-7 cells significantly, suggesting that PKCδ might play an important role in the resistance of MCF-7 cells to TRAIL. In contrast, rottlerin, U0126, and Ly294002 had no effect on MDA-MB-231 apoptosis induced by TRAIL under the same conditions. Further experiment showed that the combination of rottlerin and TRAIL cleaved PARP in the MCF-7 cells synergistically, but not in the MDA-MB-231 cells. The role of PKCδ in TRAIL-resistant MCF-7 cells was confirmed by knocking down the endogenous PKCδ expression using RNAi technology. Furthermore, caspase-3 reconstitution in MCF-7 cells was unable to alter PKCδ expression, suggesting that innate caspase-3 deficient in the cells does not cause PKCδ high expression. These data provide evidence for the first time that PKCδ plays a critical role in breast cancer cell lines to TRAIL cytotoxicity.

  5. Is diabetes a causal agent for colorectal cancer? Pathophysiological and molecular mechanisms

    Institute of Scientific and Technical Information of China (English)

    Olga Giouleme; Michael D Diamantidis; Marios G Katsaros

    2011-01-01

    The possible relationship between diabetes mellitus (DM) and colorectal cancer (CRC), concerning pathophysiological and molecular mechanisms is highlighted in this review. The most recent and complete articles and developments in this particular field were thoroughly reviewed. Common risk factors, such as obesity, sedentary lifestyle, and Western diet between DM and CRC, led to the theory that DM might be a causal agent for CRC development. Various studies have connected type 2 DM and CRC, either proximal or distal, in both sexes. Additionally, chronic insulin treatment has been linked with increased colorectal tumor risk among type 2 diabetic patients. Interestingly, elevated hemoglobin A1c has been proven to be an independent predictor of aggressive clinical behavior in CRC patients. These mechanisms include the insulin-like growth factor-hyperinsulinemia theory and the participation of oncogenic intracellular signaling pathways. Furthermore, it has been proposed that Cox-2 inhibitors might have a role in decreasing the incidence of CRC. Finally, the use of statins to reduce the risk for colon cancer in patients with diabetes has remained controversial. Diabetic patients over 50 should receive counseling regarding their elevated risk for CRC, and screening colonoscopy should be recommended before initiating insulin therapy. However, there are no current guidelines, and this strategy is not yet applicable to some countries, as the corresponding risk would not allow screening colonoscopy to be adopted. There is strong evidence to indicate that DM is a causal agent for CRC development. This conclusion provides new impetus for re-evaluating CRC screening worldwide.

  6. Hedgehog signaling antagonist GDC-0449 (Vismodegib inhibits pancreatic cancer stem cell characteristics: molecular mechanisms.

    Directory of Open Access Journals (Sweden)

    Brahma N Singh

    Full Text Available BACKGROUND: Recent evidence from in vitro and in vivo studies has demonstrated that aberrant reactivation of the Sonic Hedgehog (SHH signaling pathway regulates genes that promote cellular proliferation in various human cancer stem cells (CSCs. Therefore, the chemotherapeutic agents that inhibit activation of Gli transcription factors have emerged as promising novel therapeutic drugs for pancreatic cancer. GDC-0449 (Vismodegib, orally administrable molecule belonging to the 2-arylpyridine class, inhibits SHH signaling pathway by blocking the activities of Smoothened. The objectives of this study were to examine the molecular mechanisms by which GDC-0449 regulates human pancreatic CSC characteristics in vitro. METHODOLOGY/PRINCIPAL FINDINGS: GDC-0499 inhibited cell viability and induced apoptosis in three pancreatic cancer cell lines and pancreatic CSCs. This inhibitor also suppressed cell viability, Gli-DNA binding and transcriptional activities, and induced apoptosis through caspase-3 activation and PARP cleavage in pancreatic CSCs. GDC-0449-induced apoptosis in CSCs showed increased Fas expression and decreased expression of PDGFRα. Furthermore, Bcl-2 was down-regulated whereas TRAIL-R1/DR4 and TRAIL-R2/DR5 expression was increased following the treatment of CSCs with GDC-0449. Suppression of both Gli1 plus Gli2 by shRNA mimicked the changes in cell viability, spheroid formation, apoptosis and gene expression observed in GDC-0449-treated pancreatic CSCs. Thus, activated Gli genes repress DRs and Fas expressions, up-regulate the expressions of Bcl-2 and PDGFRα and facilitate cell survival. CONCLUSIONS/SIGNIFICANCE: These data suggest that GDC-0499 can be used for the management of pancreatic cancer by targeting pancreatic CSCs.

  7. Molecular mechanism of bitter melon juice efficacy against pancreatic cancer. | Division of Cancer Prevention

    Science.gov (United States)

    DESCRIPTION (provided by applicant): Pancreatic cancer (PanC) is an aggressive disease;median life of PanC patients post-diagnosis is been tested in several clinical trials for its anti-diabetic effects and has plenty of human safety data. We, therefore, anticipate that the positive outcomes from the proposed studies will provide compelling rationale for initiating clinical trials to establish BMJ activity against human pancreatic cancer. |

  8. Cellular and Molecular Mechanisms of 3,3′-Diindolylmethane in Gastrointestinal Cancer

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    Soo Mi Kim

    2016-07-01

    Full Text Available Studies in humans have shown that 3,3′-diindolylmethane (DIM, which is found in cruciferous vegetables, such as cabbage and broccoli, is effective in the attenuation of gastrointestinal cancers. This review presents the latest findings on the use, targets, and modes of action of DIM for the treatment of human gastrointestinal cancers. DIM acts upon several cellular and molecular processes in gastrointestinal cancer cells, including apoptosis, autophagy, invasion, cell cycle regulation, metastasis, angiogenesis, and endoplasmic reticulum (ER stress. In addition, DIM increases the efficacy of other drugs or therapeutic chemicals when used in combinatorial treatment for gastrointestinal cancer. The studies to date offer strong evidence to support the use of DIM as an anticancer and therapeutic agent for gastrointestinal cancer. Therefore, this review provides a comprehensive understanding of the preventive and therapeutic properties of DIM in addition to its different perspective on the safety of DIM in clinical applications for the treatment of gastrointestinal cancers.

  9. Prostate Cancer and Aspirin Use: Synopsis of the Proposed Molecular Mechanisms

    Science.gov (United States)

    Bilani, Nadeem; Bahmad, Hisham; Abou-Kheir, Wassim

    2017-01-01

    Background: Prostate cancer (PCa) is a critical health burden, impacting the morbidity and mortality of millions of men around the world. Most of the patients with PCa have their disease at first sensitive to androgen deprivation treatments, but later they develop resistance to therapy and eventually die of metastatic castration-resistant prostate cancer (CRPC). Although the newly developed anti-androgen therapies are effectively alleviating symptoms and prolonging lives of patients, there are still no curable treatments for CRPC. Recently, statistical studies have shown that the chronic use of aspirin might be significantly associated with better outcomes in PCa patients. Through this review, we aim to identify the different proposed molecular mechanisms relating aspirin to the pathobiology of PCa neoplasms, with a major focus on basic research done in this context. Methods: Articles were retrieved via online database searching of PubMed and MEDLINE between 1946 and September 2016. Keywords and combinations related to PCa and aspirin were used to perform the search. Abstracts of the articles were studied by two independent reviewers and then data extraction was performed on the relevant articles that met our review objectives. Results: Aspirin, a non-steroidal anti-inflammatory drug (NSAID), affects the proliferation, apoptosis, resistance and metastasis of PCa cell lines, through both COX-dependent and COX-independent mechanisms. It also lowers levels of the PCa diagnostic marker prostate specific antigen (PSA), suggesting that clinicians need to at least be aware if their patients are using Aspirin chronically. Conclusion: This review strongly warrants further consideration of the signaling cascades activated by aspirin, which may lead to new knowledge that might be applied to improve diagnosis, prognosis and treatment of PCa.

  10. Curcumin: Updated Molecular Mechanisms and Intervention Targets in Human Lung Cancer

    Directory of Open Access Journals (Sweden)

    Hong Yin

    2012-03-01

    Full Text Available Curcumin, a yellow pigment derived from Curcuma longa Linn, has attracted great interest in the research of cancer during the past decades. Extensive studies documented that curcumin attenuates cancer cell proliferation and promotes apoptosis in vivo and in vitro. Curcumin has been demonstrated to interact with multiple molecules and signal pathways, which makes it a potential adjuvant anti-cancer agent to chemotherapy. Previous investigations focus on the mechanisms of action for curcumin, which is shown to manipulate transcription factors and induce apoptosis in various kinds of human cancer. Apart from transcription factors and apoptosis, emerging studies shed light on latent targets of curcumin against epidermal growth factor receptor (EGFR, microRNAs (miRNA, autophagy and cancer stem cell. The present review predominantly discusses significance of EGFR, miRNA, autophagy and cancer stem cell in lung cancer therapy. Curcumin as a natural phytochemicals could communicate with these novel targets and show synergism to chemotherapy. Additionally, curcumin is well tolerated in humans. Therefore, EGFR-, miRNA-, autophagy- and cancer stem cell-based therapy in the presence of curcumin might be promising mechanisms and targets in the therapeutic strategy of lung cancer.

  11. Using large-scale genome variation cohorts to decipher the molecular mechanism of cancer.

    Science.gov (United States)

    Habermann, Nina; Mardin, Balca R; Yakneen, Sergei; Korbel, Jan O

    2016-01-01

    Characterizing genomic structural variations (SVs) in the human genome remains challenging, and there is a growing interest to understand somatic SVs occurring in cancer, a disease of the genome. A havoc-causing SV process known as chromothripsis scars the genome when localized chromosome shattering and repair occur in a one-off catastrophe. Recent efforts led to the development of a set of conceptual criteria for the inference of chromothripsis events in cancer genomes and to the development of experimental model systems for studying this striking DNA alteration process in vitro. We discuss these approaches, and additionally touch upon current "Big Data" efforts that employ hybrid cloud computing to enable studies of numerous cancer genomes in an effort to search for commonalities and differences in molecular DNA alteration processes in cancer.

  12. Molecular Mechanisms of p53 Deregulation in Cancer: An Overview in Multiple Myeloma.

    Science.gov (United States)

    Herrero, Ana B; Rojas, Elizabeta A; Misiewicz-Krzeminska, Irena; Krzeminski, Patryk; Gutiérrez, Norma C

    2016-11-30

    The p53 pathway is inactivated in the majority of human cancers. Although this perturbation frequently occurs through the mutation or deletion of p53 itself, there are other mechanisms that can attenuate the pathway and contribute to tumorigenesis. For example, overexpression of important p53 negative regulators, such as murine double minute 2 (MDM2) or murine double minute 4 (MDM4), epigenetic deregulation, or even alterations in TP53 mRNA splicing. In this work, we will review the different mechanisms of p53 pathway inhibition in cancer with special focus on multiple myeloma (MM), the second most common hematological malignancy, with low incidence of p53 mutations/deletions but growing evidence of indirect p53 pathway deregulation. Translational implications for MM and cancer prognosis and treatment are also reviewed.

  13. Exploring mechanisms of diet-colon cancer associations through candidate molecular interaction networks

    DEFF Research Database (Denmark)

    Westergaard, David; Li, Jun; Jensen, Kasper

    2014-01-01

    with pharmacological properties for treatment of several malignancies. Unquestionably, for developing specific intervention strategies to reduce cancer risk there is a need for a more extensive and holistic examination of the dietary components for exploring the mechanisms of action and understanding the nutrient...

  14. 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.

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

    Science.gov (United States)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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)

  17. In Vivo Anti-Cancer Mechanism of Low-Molecular-Weight Fucosylated Chondroitin Sulfate (LFCS from Sea Cucumber Cucumaria frondosa

    Directory of Open Access Journals (Sweden)

    Xiaoxiao Liu

    2016-05-01

    Full Text Available The low-molecular-weight fucosylated chondroitin sulfate (LFCS was prepared from native fucosylated chondroitin sulfate (FCS, which was extracted and isolated from sea cucumber Cucumaria frondosa, and the anti-cancer mechanism of LFCS on mouse Lewis lung carcinoma (LLC was investigated. The results showed that LFCS remarkably inhibited LLC growth and metastasis in a dose-dependent manner. LFCS induced cell cycle arrest by increasing p53/p21 expression and apoptosis through activation of caspase-3 activity in LLC cells. Meanwhile, LFCS suppressed the expression of vascular endothelial growth factor (VEGF, increased the expression of tissue inhibitor of metalloproteinase-1 (TIMP-1 and downregulated the matrix metalloproteinases (MMPs level. Furthermore, LFCS significantly suppressed the activation of ERK1/2/p38 MAPK/NF-κB pathway, which played a prime role in expression of MMPs. All of these data indicate LFCS may be used as anti-cancer drug candidates and deserve further study.

  18. The Role of Ovarian Sex Steroids in Metabolic Homeostasis, Obesity, and Postmenopausal Breast Cancer: Molecular Mechanisms and Therapeutic Implications

    Directory of Open Access Journals (Sweden)

    Viroj Boonyaratanakornkit

    2015-01-01

    Full Text Available Obese postmenopausal women have an increased risk of breast cancer and are likely to have a worse prognosis than nonobese postmenopausal women. The cessation of ovarian function after menopause results in withdrawal of ovarian sex steroid hormones, estrogen, and progesterone. Accumulating evidence suggests that the withdrawal of estrogen and progesterone causes homeostasis imbalances, including decreases in insulin sensitivity and leptin secretion and changes in glucose and lipid metabolism, resulting in a total reduction in energy expenditure. Together with a decrease in physical activity and consumption of a high fat diet, these factors significantly contribute to obesity in postmenopausal women. Obesity may contribute to breast cancer development through several mechanisms. Obesity causes localized inflammation, an increase in local estrogen production, and changes in cellular metabolism. In addition, obese women have a higher risk of insulin insensitivity, and an increase in insulin and other growth factor secretion. In this review, we describe our current understanding of the molecular actions of estrogen and progesterone and their contributions to cellular metabolism, obesity, inflammation, and postmenopausal breast cancer. We also discuss how modifications of estrogen and progesterone actions might be used as a therapeutic approach for obesity and postmenopausal breast cancer.

  19. The Potential Role of Lycopene for the Prevention and Therapy of Prostate Cancer: From Molecular Mechanisms to Clinical Evidence

    Directory of Open Access Journals (Sweden)

    Dietmar Werner Hutmacher

    2013-07-01

    Full Text Available Lycopene is a phytochemical that belongs to a group of pigments known as carotenoids. It is red, lipophilic and naturally occurring in many fruits and vegetables, with tomatoes and tomato-based products containing the highest concentrations of bioavailable lycopene. Several epidemiological studies have linked increased lycopene consumption with decreased prostate cancer risk. These findings are supported by in vitro and in vivo experiments showing that lycopene not only enhances the antioxidant response of prostate cells, but that it is even able to inhibit proliferation, induce apoptosis and decrease the metastatic capacity of prostate cancer cells. However, there is still no clearly proven clinical evidence supporting the use of lycopene in the prevention or treatment of prostate cancer, due to the only limited number of published randomized clinical trials and the varying quality of existing studies. The scope of this article is to discuss the potential impact of lycopene on prostate cancer by giving an overview about its molecular mechanisms and clinical effects.

  20. Molecular mechanism of Skp2 in promoting cervical cancer HeLa cell proliferation

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Objective: To explore the impact of s-phase kinase-associated protein 2 (Skp2) on cervical cancer cell proliferation and the relationship between Skp2 and expression of cell regulation factors and transcription factors. Methods: RNAi technology was used to silence Skp2 gene in HeLa cells. After interference, RT-PCR was used for detection of Skp-2 mRNA, and Western blotting and flow cytometry were used for protein expression analysis. Results: siRNA significantly inhibited HeLa cell proliferation (P<0.05) and increased HeLa apoptosis, and G1/G0 phase cells were increased significantly (P<0.01). Skp2 siRNA transfected HeLa cells effectively reduced Skp2 protein levels, while p27 and p-p53 protein levels were increased significantly. RT-PCR results showed that after interference Skp2 mRNA, c-myc mRNA and cyclin A mRNA expressions decreased significantly compared with those in control group (P<0.01), and p27mRNA expression level was significantly higher (P<0.01). Conclusion: The change of Skp2 expression affects the expression of the cell cycle protein, thus affecting proliferation and apoptosis of HeLa cells. Skp2 protein plays an important role in the progression of cervical cancer; yet the specific mechanism still needs further study.

  1. Molecular mechanism of chemoresistance by miR-215 in osteosarcoma and colon cancer cells

    Directory of Open Access Journals (Sweden)

    Formentini Andrea

    2010-04-01

    Full Text Available Abstract Background Translational control mediated by non-coding microRNAs (miRNAs plays a key role in the mechanism of cellular resistance to anti-cancer drug treatment. Dihydrofolate reductase (DHFR and thymidylate synthase (TYMS, TS are two of the most important targets for antifolate- and fluoropyrimidine-based chemotherapies in the past 50 years. In this study, we investigated the roles of miR-215 in the chemoresistance to DHFR inhibitor methotrexate (MTX and TS inhibitor Tomudex (TDX. Results The protein levels of both DHFR and TS were suppressed by miR-215 without the alteration of the target mRNA transcript levels. Interestingly, despite the down-regulation of DHFR and TS proteins, ectopic expression of miR-215 resulted in a decreased sensitivity to MTX and TDX. Paradoxically, gene-specific small-interfering RNAs (siRNAs against DHFR or TS had the opposite effect, increasing sensitivity to MTX and TDX. Further studies revealed that over-expression of miR-215 inhibited cell proliferation and triggered cell cycle arrest at G2 phase, and that this effect was accompanied by a p53-dependent up-regulation of p21. The inhibitory effect on cell proliferation was more pronounced in cell lines containing wild-type p53, but was not seen in cells transfected with siRNAs against DHFR or TS. Moreover, denticleless protein homolog (DTL, a cell cycle-regulated nuclear and centrosome protein, was confirmed to be one of the critical targets of miR-215, and knock-down of DTL by siRNA resulted in enhanced G2-arrest, p53 and p21 induction, and reduced cell proliferation. Additionally, cells subjected to siRNA against DTL exhibited increased chemoresistance to MTX and TDX. Endogenous miR-215 was elevated about 3-fold in CD133+HI/CD44+HI colon cancer stem cells that exhibit slow proliferating rate and chemoresistance compared to control bulk CD133+/CD44+ colon cancer cells. Conclusions Taken together, our results indicate that miR-215, through the suppression

  2. The role of leptin in gastric cancer: Clinicopathologic features and molecular mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kang Nyeong [Department of Internal Medicine, Hanyang University College of Medicine, Seoul (Korea, Republic of); Choi, Ho Soon, E-mail: hschoi96@hanyang.ac.kr [Department of Internal Medicine, Hanyang University College of Medicine, Seoul (Korea, Republic of); Yang, Sun Young [Department of Internal Medicine, Healthcare Research Institute, Seoul National University Hospital Healthcare System Gangnam Center, Seoul (Korea, Republic of); Park, Hyun Ki; Lee, Young Yiul; Lee, Oh Young; Yoon, Byung Chul; Hahm, Joon Soo [Department of Internal Medicine, Hanyang University College of Medicine, Seoul (Korea, Republic of); Paik, Seung Sam [Pathology, Hanyang University College of Medicine, Seoul (Korea, Republic of)

    2014-04-18

    Highlights: • Leptin and Ob-R are expressed in gastric adenoma and early and advanced cancer. • Leptin is more likely associated with differentiated gastric cancer or cardia cancer. • Leptin proliferates gastric cancer cells via activating the STAT3 and ERK1/2 pathways. - Abstract: Obesity is associated with certain types of cancer, including gastric cancer. However, it is still unclear whether obesity-related cytokine, leptin, is implicated in gastric cancer. Therefore, we aimed to investigate the role of leptin in gastric cancer. The expression of leptin and its receptor, Ob-R, was assessed by immunohistochemical staining and was compared in patients with gastric adenoma (n = 38), early gastric cancer (EGC) (n = 38), and advanced gastric cancer (AGC) (n = 38), as a function of their clinicopathological characteristics. Gastric cancer cell lines were studied to investigate the effects of leptin on the signal transducer and activator of transcription-3 (STAT3) and extracellular receptor kinase 1/2 (ERK1/2) signaling pathways using MTT assays, immunoblotting, and inhibition studies. Leptin was expressed in gastric adenomas (42.1%), EGCs (47.4%), and AGCs (43.4%). Ob-R expression tended to increase from gastric adenoma (2%), through EGC (8%), to AGC (18%). Leptin induced the proliferation of gastric cancer cells by activating STAT3 and ERK1/2 and up-regulating the expression of vascular endothelial growth factor (VEGF). Blocking Ob-R with pharmacological inhibitors and by RNAi decreased both the leptin-induced activation of STAT3 and ERK1/2 and the leptin-induced expression of VEGF. Leptin plays a role in gastric cancer by stimulating the proliferation of gastric cancer cells via activating the STAT3 and ERK1/2 pathways.

  3. Molecular Mechanisms by Which a Fucus vesiculosus Extract Mediates Cell Cycle Inhibition and Cell Death in Pancreatic Cancer Cells

    Directory of Open Access Journals (Sweden)

    Ulf Geisen

    2015-07-01

    Full Text Available Pancreatic cancer is one of the most aggressive cancer entities, with an extremely poor 5-year survival rate. Therefore, novel therapeutic agents with specific modes of action are urgently needed. Marine organisms represent a promising source to identify new pharmacologically active substances. Secondary metabolites derived from marine algae are of particular interest. The present work describes cellular and molecular mechanisms induced by an HPLC-fractionated, hydrophilic extract derived from the Baltic brown seaweed Fucus vesiculosus (Fv1. Treatment with Fv1 resulted in a strong inhibition of viability in various pancreatic cancer cell lines. This extract inhibited the cell cycle of proliferating cells due to the up-regulation of cell cycle inhibitors, shown on the mRNA (microarray data and protein level. As a result, cells were dying in a caspase-independent manner. Experiments with non-dividing cells showed that proliferation is a prerequisite for the effectiveness of Fv1. Importantly, Fv1 showed low cytotoxic activity against non-malignant resting T cells and terminally differentiated cells like erythrocytes. Interestingly, accelerated killing effects were observed in combination with inhibitors of autophagy. Our in vitro data suggest that Fv1 may represent a promising new agent that deserves further development towards clinical application.

  4. Molecular Mechanisms by Which a Fucus vesiculosus Extract Mediates Cell Cycle Inhibition and Cell Death in Pancreatic Cancer Cells.

    Science.gov (United States)

    Geisen, Ulf; Zenthoefer, Marion; Peipp, Matthias; Kerber, Jannik; Plenge, Johannes; Managò, Antonella; Fuhrmann, Markus; Geyer, Roland; Hennig, Steffen; Adam, Dieter; Piker, Levent; Rimbach, Gerald; Kalthoff, Holger

    2015-07-20

    Pancreatic cancer is one of the most aggressive cancer entities, with an extremely poor 5-year survival rate. Therefore, novel therapeutic agents with specific modes of action are urgently needed. Marine organisms represent a promising source to identify new pharmacologically active substances. Secondary metabolites derived from marine algae are of particular interest. The present work describes cellular and molecular mechanisms induced by an HPLC-fractionated, hydrophilic extract derived from the Baltic brown seaweed Fucus vesiculosus (Fv1). Treatment with Fv1 resulted in a strong inhibition of viability in various pancreatic cancer cell lines. This extract inhibited the cell cycle of proliferating cells due to the up-regulation of cell cycle inhibitors, shown on the mRNA (microarray data) and protein level. As a result, cells were dying in a caspase-independent manner. Experiments with non-dividing cells showed that proliferation is a prerequisite for the effectiveness of Fv1. Importantly, Fv1 showed low cytotoxic activity against non-malignant resting T cells and terminally differentiated cells like erythrocytes. Interestingly, accelerated killing effects were observed in combination with inhibitors of autophagy. Our in vitro data suggest that Fv1 may represent a promising new agent that deserves further development towards clinical application.

  5. The role of leptin in gastric cancer: clinicopathologic features and molecular mechanisms.

    Science.gov (United States)

    Lee, Kang Nyeong; Choi, Ho Soon; Yang, Sun Young; Park, Hyun Ki; Lee, Young Yiul; Lee, Oh Young; Yoon, Byung Chul; Hahm, Joon Soo; Paik, Seung Sam

    2014-04-18

    Obesity is associated with certain types of cancer, including gastric cancer. However, it is still unclear whether obesity-related cytokine, leptin, is implicated in gastric cancer. Therefore, we aimed to investigate the role of leptin in gastric cancer. The expression of leptin and its receptor, Ob-R, was assessed by immunohistochemical staining and was compared in patients with gastric adenoma (n=38), early gastric cancer (EGC) (n=38), and advanced gastric cancer (AGC) (n=38), as a function of their clinicopathological characteristics. Gastric cancer cell lines were studied to investigate the effects of leptin on the signal transducer and activator of transcription-3 (STAT3) and extracellular receptor kinase 1/2 (ERK1/2) signaling pathways using MTT assays, immunoblotting, and inhibition studies. Leptin was expressed in gastric adenomas (42.1%), EGCs (47.4%), and AGCs (43.4%). Ob-R expression tended to increase from gastric adenoma (2%), through EGC (8%), to AGC (18%). Leptin induced the proliferation of gastric cancer cells by activating STAT3 and ERK1/2 and up-regulating the expression of vascular endothelial growth factor (VEGF). Blocking Ob-R with pharmacological inhibitors and by RNAi decreased both the leptin-induced activation of STAT3 and ERK1/2 and the leptin-induced expression of VEGF. Leptin plays a role in gastric cancer by stimulating the proliferation of gastric cancer cells via activating the STAT3 and ERK1/2 pathways.

  6. Molecular Mechanisms of Preeclampsia

    OpenAIRE

    N. Vitoratos; D. Hassiakos; Iavazzo, C.

    2012-01-01

    Preeclampsia is one of the leading causes of maternal morbidity/mortality. The pathogenesis of preeclampsia is still under investigation. The aim of this paper is to present the molecular mechanisms implicating in the pathway leading to preeclampsia.

  7. Transcriptional networks controlling breast cancer metastasis : molecular mechanisms shaping the SOX4 response

    NARCIS (Netherlands)

    Vervoort, S.J.

    2015-01-01

    Breast cancer is the most commonly diagnosed cancer in women. Despite great improvements in diagnosis and treatment of this disease, mortality remains high due to the development of metastatic disease resulting in clinical relapse. The majority of current treatment options primarily target the prima

  8. Molecular phenotyping of human ovarian cancer stem cells unravels the mechanisms for repair and chemoresistance

    DEFF Research Database (Denmark)

    Alvero, Ayesha B; Chen, Rui; Fu, Han-Hsuan

    2009-01-01

    A major burden in the treatment of ovarian cancer is the high percentage of recurrence and chemoresistance. Cancer stem cells (CSCs) provide a reservoir of cells that can self-renew, can maintain the tumor by generating differentiated cells [non-stem cells (non-CSCs)] which make up the bulk of th...

  9. Molecular mechanisms for inhibition of colon cancer cells by combined epigenetic-modulating epigallocatechin gallate and sodium butyrate

    Energy Technology Data Exchange (ETDEWEB)

    Saldanha, Sabita N., E-mail: sabivan@uab.edu [Department of Biology, University of Alabama at Birmingham, 175 Campbell Hall, 1300 University Boulevard, Birmingham, AL 35294 (United States); Department of Biological Sciences, Alabama State University, Montgomery, AL 36104 (United States); Kala, Rishabh [Department of Biology, University of Alabama at Birmingham, 175 Campbell Hall, 1300 University Boulevard, Birmingham, AL 35294 (United States); Tollefsbol, Trygve O., E-mail: trygve@uab.edu [Department of Biology, University of Alabama at Birmingham, 175 Campbell Hall, 1300 University Boulevard, Birmingham, AL 35294 (United States); Comprehensive Cancer Center, University of Alabama at Birmingham, Birmingham, AL 35294 (United States); Comprehensive Center for Healthy Aging, University of Alabama at Birmingham, Birmingham, AL 35294 (United States); Nutrition Obesity Research Center, University of Alabama at Birmingham, Birmingham, AL 35294 (United States); Comprehensive Diabetes Research Center, University of Alabama at Birmingham, Birmingham, AL 35294 (United States)

    2014-05-15

    Bioactive compounds are considered safe and have been shown to alter genetic and epigenetic profiles of tumor cells. However, many of these changes have been reported at molecular concentrations higher than physiologically achievable levels. We investigated the role of the combinatorial effects of epigallocatechin gallate (EGCG), a predominant polyphenol in green tea, and sodium butyrate (NaB), a dietary microbial fermentation product of fiber, in the regulation of survivin, which is an overexpressed anti-apoptotic protein in colon cancer cells. For the first time, our study showed that the combination treatment induced apoptosis and cell cycle arrest in RKO, HCT-116 and HT-29 colorectal cancer cells. This was found to be regulated by the decrease in HDAC1, DNMT1, survivin and HDAC activity in all three cell lines. A G2/M arrest was observed for RKO and HCT-116 cells, and G1 arrest for HT-29 colorectal cancer cells for combinatorial treatment. Further experimentation of the molecular mechanisms in RKO colorectal cancer (CRC) cells revealed a p53-dependent induction of p21 and an increase in nuclear factor kappa B (NF-κB)-p65. An increase in double strand breaks as determined by gamma-H2A histone family member X (γ-H2AX) protein levels and induction of histone H3 hyperacetylation was also observed with the combination treatment. Further, we observed a decrease in global CpG methylation. Taken together, these findings suggest that at low and physiologically achievable concentrations, combinatorial EGCG and NaB are effective in promoting apoptosis, inducing cell cycle arrest and DNA-damage in CRC cells. - Highlights: • EGCG and NaB as a combination inhibits colorectal cancer cell proliferation. • The combination treatment induces DNA damage, G2/M and G1 arrest and apoptosis. • Survivin is effectively down-regulated by the combination treatment. • p21 and p53 expressions are induced by the combination treatment. • Epigenetic proteins DNMT1 and HDAC1 are

  10. Current Molecular Targeted Therapy in Advanced Gastric Cancer: A Comprehensive Review of Therapeutic Mechanism, Clinical Trials, and Practical Application

    Directory of Open Access Journals (Sweden)

    Kaichun Li

    2016-01-01

    Full Text Available Despite the great progress in the treatment of gastric cancer, it is still the third leading cause of cancer death worldwide. Patients often miss the opportunity for a surgical cure, because the cancer has already developed into advanced cancer when identified. Compared to best supportive care, chemotherapy can improve quality of life and prolong survival time, but the overall survival is often short. Due to the molecular study of gastric cancer, new molecular targeted drugs have entered the clinical use. Trastuzumab, an antibody targeting human epidermal growth factor receptor 2 (HER2, can significantly improve survival in advanced gastric cancer patients with HER2 overexpression. Second-line treatment of advanced gastric cancer with ramucirumab, an antibody targeting VEGFR-2, alone or in combination with paclitaxel, has been proved to provide a beneficial effect. The VEGFR-2 tyrosine kinase inhibitor, apatinib, can improve the survival of advanced gastric cancer patients after second-line chemotherapy failure. Unfortunately, none of the EGFR targeting antibodies (cetuximab or panitumumab, VEGF targeting monoclonal antibodies (bevacizumab, mTOR inhibitor (everolimus, or HGF/MET pathway targeting drugs has a significant survival benefit. Many other clinical trials based on molecular markers are underway. This review will summarize targeted therapies for advanced gastric cancer.

  11. Experimental Studies on Cyclooxygenase-2 Inhibitor Induced Cervical Cancer Hela Cell Apoptosis and Its Molecular Mechanism

    Institute of Scientific and Technical Information of China (English)

    Ling YIN; Li-bei WEI; Qiu-hong QU; Xiao-peng GUO

    2007-01-01

    Objective To investigate the Hela cells growth inhibition and apoptosis possible molecular mechanisms.Methods Hela cells were treated with various concentrations(100 μmol/L,200 μmol/L,300μmol/L,400 μmol/L) ofNS-398 (selective for COX-2 inhibition). Cell growth was measured by MTT (Thiazolyl blue).Apoptosis was detected by double staining flow cytomezry (FCM).Levels of PGE2 were measured by radioimmunoassay.The expressions of COX-2 protein were also examined by Western blot analysis.Results After treated with different concentrations ofNS-398,the growth of Hela cells was suppressed significantly in a dose-and time-dependent manner (P<0. 01).The NS-398 can induce apoptosis with the apoptosis rates at 8.53%-43.46% by FCM in a dose-dependent manner.The release of PGE2 was reduced in Hela cells with the values of 69.26 ±2.13, 47.46 ±2.18,28.15 ± 1.64 and 17.01 ± 1.12,respectively,there was significant difference compared with control group (83.78 ± 1.11)(P<0. 01).The NS-398 could inhibit the activity and expression of COX-2 in a dosedependent manner and down-regulated the expression of COX-2 protein greatly.Conclusion NS-398 could inhibit the proliferation and increase apoptosis in human Hela cells.These effects may be depended on the inhibition of the expression of COX-2 and PGE2 by NS-398.

  12. How circulating tumor cells escape from multidrug resistance: translating molecular mechanisms in metastatic breast cancer treatment.

    Science.gov (United States)

    Gradilone, Angela; Raimondi, Cristina; Naso, Giuseppe; Silvestri, Ida; Repetto, Lazzaro; Palazzo, Antonella; Gianni, Walter; Frati, Luigi; Cortesi, Enrico; Gazzaniga, Paola

    2011-12-01

    Resistance to anthracyclines is responsible for treatment failure in most patients with metastatic breast cancer. According to recent studies, the expression of specific drug transporters (MRPs) on circulating tumor cells is predictive of prognosis in different cancer types. We observed that patients whose circulating tumor cells expressed MRP1 and MRP2, two drug-export pumps responsible for anthracyclines efflux, who received conventional anthracyclines had a significantly shorter time to progression compared with patients sharing same characteristics who received non pegylated liposomal doxorubicin (P < 0.005). These results may highlight a new appealing role of the liposomal doxorubicin formulation, not only because of its reduced cardiac toxicity but especially referring to its theoretical efficacy in anthracycline-resistant breast cancer patients.

  13. Combined therapeutic effect and molecular mechanisms of metformin and cisplatin in human lung cancer xenografts in nude mice

    Directory of Open Access Journals (Sweden)

    Yu-Qin Chen

    2015-01-01

    Full Text Available Objective: This work was aimed at studying the inhibitory activity of metformin combined with the commonly used chemotherapy drug cisplatin in human lung cancer xenografts in nude mice. We also examined the combined effects of these drugs on the molecular expression of survivin, matrix metalloproteinase-2 (MMP-2, vascular endothelial growth factor-C (VEGF-C, and vascular endothelial growth factorreceptor-3 (VEGFR-3 to determine the mechanism of action and to explore the potential applications of the new effective drug therapy in lung cancer. Materials and Methods: The nude mice model of lung cancer xenografts was established, and mice were randomly divided into the metformin group, the cisplatin group, the metformin + cisplatin group, and the control group. The animals were killed 42 days after drug administration, and the tumor tissues were then sampled to detect the messenger ribonucleic acid (mRNA and protein expression levels of survivin, MMP-2, VEGF-C, and VEGFR-3 by immunohistochemistry and reverse transcription polymerase chain reaction (RT-PCR. Results: The protein and mRNA expression levels of survivin, MMP-2, VEGF-C, and VEGFR-3 in the cisplatin group and the combined treatment group were lower than that in the control group (P < 0.05. In the metformin group, the expression of MMP-2 protein and mRNA was lower than that in the control group (P < 0.05. The protein and mRNA expression levels of survivin, MMP-2, VEGF-C, and VEGFR-3 in the combined treatment group were lower than that in the cisplatin group and the metformin group (P < 0.05. Conclusions: Metformin inhibited the expression of MMP-2, cisplatin and the combined treatment inhibited the expression of survivin, MMP-2, VEGF-C, and VEGFR-3, and the combined treatment of metformin with cisplatin resulted in enhanced anti-tumor efficacy.

  14. Molecular mechanisms involved in the inhibition of MDA-MB-435 breast cancer cells by phenolic acids from the red-flesh peach BY00P6653

    Science.gov (United States)

    A wide variety of fruits and vegetables extracts have been shown to protect against cancer cell growth in vitro. Increasing evidence suggests that phenolics compounds found in fruits and vegetables may have anticancer properties. However, the molecular mechanisms involved in the anti-proliferative...

  15. Change of the cell cycle after flutamide treatment in prostate cancer cells and its molecular mechanism

    Institute of Scientific and Technical Information of China (English)

    Yong Wang; Wei-Jun Qin; He Wang; Guo-Xing Shao; Chen Shao; Chang-Hong Shi; Lei Zhang; Hong-Hong Yue; Peng-Fei Wang; Bo Yang; Yun-Tao Zhang; Fan Liu

    2005-01-01

    Aim: To explore the effect of androgen receptor (AR) on the expression of the cell cycle-related genes, such as CDKN1A and BTG1, in prostate cancer cell line LNCaP. Methods: After AR antagonist flutamide treatment and confirmation of its effect by phase contrast microscope and flow cytometry, the differential expression of the cell cycle-related genes was analyzed by a cDNA microarray. The flutamide treated cells were set as the experimental group and the LNCaP cells as the control. We labeled cDNA probes of the experimental group and control group with Cy5 and Cy3 dyes, respectively, through reverse transcription. Then we hybridized the cDNA probes with cDNA microarrays, which contained 8 126 unique human cDNA sequences and the chip was scanned to get the fluorescent values of Cy5 and Cy3 on each spot. After primary analysis, reverse transcription polymerase chain reaction (RTPCR) tests were carried out to confirm the results of the chips. Results:After AR antagonist flutamide treatment,three hundred and twenty-six genes (3.93 %) expressed differentially, 97 down-regulated and 219 up-regulated.Among them, eight up-regulated genes might be cell cycle-related, namely CDC10, NRAS, BTG1, Weel, CLK3,DKFZP564A122, CDKN1A and BTG2. The CDKN1A and BTG1 gene mRNA expression was confirmed to be higher in the experimental group by RT-PCR, whilep53 mRNA expression had no significant changes. Conclusion: Flutamide treatment might up-regulate CDKN1A and BTG1 expression in prostate cancer cells. The protein expressions of CDKN1A and BTG1 play an important role in inhibiting the proliferation of cancer cells. CDKN1A has a great impact on the cell cycle of prostate cancer cells and may play a role in the cancer cells in a p53-independent pathway. The prostate cancer cells might affect the cell cycle-related genes by activating AR and thus break the cell cycle control.

  16. Molecular Mechanism of BCAR3-p130Cas in Breast Cancer

    Science.gov (United States)

    2013-05-01

    et al. PEA-15 inhibits tumorigenesis in an MDA-MB-468 triple -negative breast cancer xenograft model through increased cytoplasmic localization of...was not included in the model . The C-terminal domain of p130Cas is defined by electron density from residues 739–872 and adopts the four- helix ...crystallization (months 3-6). 1c. Diffraction data collection and structure determination (months 6-12). 1d. Model building and analysis (months 6-12

  17. Anticancer molecular mechanisms of resveratrol

    Directory of Open Access Journals (Sweden)

    Elena Maria Varoni

    2016-04-01

    Full Text Available Resveratrol is a pleiotropic phytochemical belonging to the stilbene family. Despite it is only significantly present in grape products, a huge amount of preclinical studies investigated its anticancer properties in a plethora of cellular and animal models. Molecular mechanisms of resveratrol involved signaling pathways related to: extracellular growth factors and receptor tyrosine kinases; formation of multiprotein complexes and cell metabolism; cell proliferation and genome instability; cytoplasmic tyrosine kinase signaling (cytokine, integrin and developmental pathways; signal transduction by the transforming growth factor-β super-family; apoptosis and inflammation; immune-surveillance and hormone signaling. Resveratrol also showed a promising role to counteract multi-drug resistance: in adjuvant therapy, associated with 5-fluoruracyl and cisplatin, resveratrol had additive and/or synergistic effects increasing the chemosensitization of cancer cells. Resveratrol, by acting on diverse mechanisms simultaneously, has been emphasized as a promising, multi-target, anticancer agent, relevant in both cancer prevention and treatment.

  18. Protective effect of ulinastatin on acute lung injury after radiotherapy in patients with lung cancer and the related molecular mechanism

    Institute of Scientific and Technical Information of China (English)

    Guang-Ping Fan

    2016-01-01

    Objective:To analyze the protective effect of ulinastatin on acute lung injury after radiotherapy in patients with lung cancer and the related molecular mechanism.Methods:A total of 78 patients who received radiotherapy and developed acute lung injury in our hospital between December 2013 and December 2015 were randomly divided into observation group and control group, control group received symptomatic treatment, observation group received symptomatic + ulinastatin treatment, and the content of growth factors, inflammatory factors, disease-related proteins in serum as well as the expression of P38MAPK signaling pathway molecules in alveolar lavage fluid were compared between two groups of patients after treatment.Results:Ten days after treatment, HGF, KGF, VEGF, IL-1β, IL-8, IL-10, IL-18, IL-13, PCT, S100A8, S100A9 and SP-D content in serum of observation group were significantly lower than those of control group while Clara cell protein content was significantly higher than that of control group; phosphorylated p38MAPK, MAPK, MKK3/6 and ATF-2 protein expression levels in alveolar lavage fluid were significantly lower than those of control group.Conclusions:Ulinastatin can alleviate the overall condition in patients with acute lung injury after radiotherapy, and the specific mechanism is associated with P38MAPK signaling pathway.

  19. Non-small-cell lung cancer: molecular targeted therapy and personalized medicine – drug resistance, mechanisms, and strategies

    Directory of Open Access Journals (Sweden)

    Sechler M

    2013-04-01

    Full Text Available Marybeth Sechler,1,2 Amber D Cizmic,3 Sreedevi Avasarala,1 Michelle Van Scoyk,1 Christine Brzezinski,1 Nicole Kelley,1 Rama Kamesh Bikkavilli,1 Robert A Winn1–3 1Division of Pulmonary Sciences and Critical Care, 2Program in Cancer Biology, University of Colorado, Aurora, CO, USA; 3Veterans Affairs Medical Center, Denver, CO, USA Abstract: Targeted therapies for cancer bring the hope of specific treatment, providing high efficacy and in some cases lower toxicity than conventional treatment. Although targeted therapeutics have helped immensely in the treatment of several cancers, like chronic myelogenous leukemia, colon cancer, and breast cancer, the benefit of these agents in the treatment of lung cancer remains limited, in part due to the development of drug resistance. In this review, we discuss the mechanisms of drug resistance and the current strategies used to treat lung cancer. A better understanding of these drug-resistance mechanisms could potentially benefit from the development of a more robust personalized medicine approach for the treatment of lung cancer. Keywords: lung cancer, drug targets, personalized medicine, NSCLC

  20. Glycoprotein mucin molecular brush on cancer cell surface acting as mechanical barrier against drug delivery

    Science.gov (United States)

    Wang, Xin; Shah, Aalok A.; Campbell, Robert B.; Wan, Kai-tak

    2010-12-01

    Uptake of cytotoxic drugs by typical tumor cells is limited by the dense dendritic network of oligosaccharide mucin chains that forms a mechanical barrier. Atomic force microscopy is used to directly measure the force needed to pierce the mucin layer to reach the cell surface. Measurements are analyzed by de Gennes' steric reptation theory. Multidrug resistant ovarian tumor cells shows significantly larger penetration load compared to the wide type. A pool of pancreatic, lung, colorectal, and breast cells are also characterized. The chemotherapeutic agent, benzyl-α-GalNac, for inhibiting glycosylation is shown to be effective in reducing the mechanical barrier.

  1. Molecular biology of pancreatic cancer

    Institute of Scientific and Technical Information of China (English)

    Miroslav Zavoral; Petra Minarikova; Filip Zavada; Cyril Salek; Marek Minarik

    2011-01-01

    In spite of continuous research efforts directed at early detection and treatment of pancreatic cancer, the outlook for patients affected by the disease remains dismal. With most cases still being diagnosed at advanced stages, no improvement in survival prognosis is achieved with current diagnostic imaging approaches. In the absence of a dominant precancerous condition, several risk factors have been identified including family history, chronic pancreatitis, smoking, diabetes mellitus, as well as certain genetic disorders such as hereditary pancreatitis, cystic fibrosis, familial atypical multiple Most pancreatic carcinomas, however, remain sporadic. Current progress in experimental molecular techniques has enabled detailed understanding of the molecular processes of pancreatic cancer development. According to the latest information, malignant pancreatic transformation involves multiple oncogenes and tumor-suppressor genes that are involved in a variety of signaling pathways. The most characteristic aberrations (somatic point mutations and allelic losses) affect oncogenes and tumor-suppressor genes within RAS, AKT and Wnt signaling, and have a key role in transcription and proliferation, as well as systems that regulate the cell cycle (SMAD/DPC, CDKN2A/p16) and apoptosis (TP53). Understanding of the underlying molecular mechanisms should promote development of new methodology for early diagnosis and facilitate improvement in current approaches for pancreatic cancer treatment.

  2. Advances in the Molecular Mechanisms and Prognostic Significance of EMT 
in Non-small Cell Lung Cancer

    Directory of Open Access Journals (Sweden)

    Qinchen CAO

    2014-07-01

    Full Text Available Epithelial to mesenchymal transition (EMT has an important role in the development of embryo, as well as that in the metastasis of non-small cell lung cancer (NSCLC. Recent researches have demonstrated that both morphological and phenotypic conversions emerge in cells undergoing EMT. As most of relevant studies were on other cancers, it is essential to uncover whether it is the similar mechanisms accounting for EMT in NSCLC. With the progress of the studies, EMT-related basic researches are gradually applied to predicting the prognosis of NSCLC. The aim of this article was to discuss the mechanisms related to EMT emerging in NSCLC.

  3. Understanding molecular structure from molecular mechanics.

    Science.gov (United States)

    Allinger, Norman L

    2011-04-01

    Molecular mechanics gives us a well known model of molecular structure. It is less widely recognized that valence bond theory gives us structures which offer a direct interpretation of molecular mechanics formulations and parameters. The electronic effects well-known in physical organic chemistry can be directly interpreted in terms of valence bond structures, and hence quantitatively calculated and understood. The basic theory is outlined in this paper, and examples of the effects, and their interpretation in illustrative examples is presented.

  4. Mechanisms of cancer metastasis to the bone

    Institute of Scientific and Technical Information of China (English)

    Juan Juan YIN; Claire B. POLLOCK; Kathleen KELLY

    2005-01-01

    Some of the most common human cancers, including breast cancer, prostate cancer, and lung cancer, metastasize with avidity to bone. What is the basis for their preferential growth within the bone microenvironment? Bidirectional interactions between tumor cells and cells that make up bone result in a selective advantage for tumor growth and can lead to bone destruction or new bone matrix deposition. This review discusses our current understanding of the molecular components and mechanisms that are responsible for those interactions.

  5. The molecular biology of cancer.

    Science.gov (United States)

    Bertram, J S

    2000-12-01

    The process by which normal cells become progressively transformed to malignancy is now known to require the sequential acquisition of mutations which arise as a consequence of damage to the genome. This damage can be the result of endogenous processes such as errors in replication of DNA, the intrinsic chemical instability of certain DNA bases or from attack by free radicals generated during metabolism. DNA damage can also result from interactions with exogenous agents such as ionizing radiation, UV radiation and chemical carcinogens. Cells have evolved means to repair such damage, but for various reasons errors occur and permanent changes in the genome, mutations, are introduced. Some inactivating mutations occur in genes responsible for maintaining genomic integrity facilitating the acquisition of additional mutations. This review seeks first to identify sources of mutational damage so as to identify the basic causes of human cancer. Through an understanding of cause, prevention may be possible. The evolution of the normal cell to a malignant one involves processes by which genes involved in normal homeostatic mechanisms that control proliferation and cell death suffer mutational damage which results in the activation of genes stimulating proliferation or protection against cell death, the oncogenes, and the inactivation of genes which would normally inhibit proliferation, the tumor suppressor genes. Finally, having overcome normal controls on cell birth and cell death, an aspiring cancer cell faces two new challenges: it must overcome replicative senescence and become immortal and it must obtain adequate supplies of nutrients and oxygen to maintain this high rate of proliferation. This review examines the process of the sequential acquisition of mutations from the prospective of Darwinian evolution. Here, the fittest cell is one that survives to form a new population of genetically distinct cells, the tumor. This review does not attempt to be comprehensive but

  6. Breast cancer heterogeneity: mechanisms, proofs, and implications

    Directory of Open Access Journals (Sweden)

    Yi-Hsuan Hsiao, Ming-Chih Chou, Carol Fowler, Jeffrey T. Mason, Yan-gao Man

    2010-01-01

    Full Text Available Human breast cancer represents a group of highly heterogeneous lesions consisting of about 20 morphologically distinct subtypes with substantially different molecular and/or biochemical signatures, clinical courses, and prognoses. This study analyzed the possible correlation between the morphological presentations of breast cancer and two hypothesized models of carcinogenesis, in order to identify the intrinsic mechanism(s and clinical implications of breast cancer heterogeneity.

  7. 乳腺癌骨转移分子机制研究进展%Research progress on the molecular mechanism of breast cancer bone metastasis

    Institute of Scientific and Technical Information of China (English)

    曾慧娟(综述); 王少华(审校)

    2015-01-01

    Breast cancer is one of the most common malignant tumors in women. Bone is commonly affected in the context of metastatic breast cancer.Once bone metastasis happens, patient would experience poor prognosis and impaired quality of life.However, there is a lack of approaches for more sensitive and specific diagnosis and treatments for breast cancer bone metastasis.Thus, it is im-perative to find new treatment target from molecular mechanism.In this paper, we review the current research progress on the molecular mechanism from several levels including gene profile, proteins and microRNAs.We also review the establishment of animal models of breast cancer bone metastasis.With the achievements acquired in the completed or undergoing researches on breast cancer bone metasta-sis, we hope the finding of the optimal diagnostic and therapeutic targets could lead the breast cancer research into a new era.%乳腺癌是女性最常见的恶性肿瘤之一,骨为其最易发生转移的部位。一旦发生骨转移,患者预后及生活质量明显下降,然而目前仍缺乏有力证据证实的、能够应用于临床的特异性诊疗手段。因此,迫切需要从其分子机制入手,寻找新的分子靶点。文中就乳腺癌骨转移在基因、蛋白及miRNA3个层面机制的研究进展作一综述,并阐述了乳腺癌骨转移动物模型的建立方法。

  8. Biological Significance and the Related Molecular Mechanism of Ets1 mRNA Expression in Lung Cancer by Tissue Microarray (TMA)

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Objective: To investigate the expressions and molecular mechanism of Ets-1 mRNA, and TGFβ1 and c-Met proteins in the pathogenesis, progression of lung cancer by tissue microarray (TMA) method. Methods: The expressions of Ets-1 mRNA, and TGFβ1 and c-Met proteins were detected in 89 primary lung cancers, 12 lung cancer with lymph-node metastasis and 12 precancerous lesions by FISH(fluorescence in situ hybridization) and immunohistochemical method, and 10 normal lung tissues were used as controls. Results: The expressions of Ets-1 mRNA, and TGFβ1 and c-Met proteins were significantly higher in 89 primary lung cancer than in the control group (P<0.05). The expressions of Ets-1 mRNA, and TGFβ1 and c-Met proteins were related to lymph node metastasis and clinical stages. There was a positive correlation between the Ets-1 mRNA expression and TGFβ1 and c-Met proteins (P<0.05). Conclusion: Ets-1 mRNA, TGFβ1 and c-Met proteins may be related to the pathogenesis, progression and malignant behavior of lung cancer. They may play an important role in prognosis assessment of lung cancer.

  9. In silico analysis of molecular mechanisms of Galanthus nivalis agglutinin-related lectin-induced cancer cell death from carbohydrate-binding motif evolution hypothesis.

    Science.gov (United States)

    Yu, Qi-Jia; Li, Zi-Yue; Yao, Shun; Ming, Miao; Wang, Shu-Ya; Liu, Bo; Bao, Jin-Ku

    2011-10-01

    Galanthus nivalis agglutinin-related lectins, a superfamily of strictly mannose-binding-specific lectins widespread amongst monotyledonous plants, have drawn a rising attention for their remarkable anti-proliferative and apoptosis-inducing activities toward various types of cancer cells; however, the precise molecular mechanisms by which they induce tumor cell apoptosis are still only rudimentarily understood. Herein, we found that the three conserved motifs "QXDXNXVXY," the mannose-specific binding sites, could mutate at one or more amino acid sites, which might be a driving force for the sequential evolution and thus ultimately leading to the complete disappearance of the three conserved motifs. In addition, we found that the motif evolution could result in the diversification of sugar-binding types that G. nivalis agglutinin-related lectins could bind from specific mannose receptors to more types of sugar-containing receptors in cancer cells. Subsequently, we indicated that some sugar-containing receptors such as TNFR1, EGFR, Hsp90, and Hsp70 could block downstream anti-apoptotic or survival signaling pathways, which, in turn, resulted in tumor cell apoptosis. Taken together, our hypothesis that carbohydrate-binding motif evolution may impact the G. nivalis agglutinin-related lectin-induced survival or anti-apoptotic pathways would provide a new perspective for further elucidating the intricate relationships between the carbohydrate-binding specificities and complex molecular mechanisms by which G. nivalis agglutinin-related lectins induce cancer cell death.

  10. Molecular and genetic bases of pancreatic cancer.

    Science.gov (United States)

    Vaccaro, Vanja; Gelibter, Alain; Bria, Emilio; Iapicca, Pierluigi; Cappello, Paola; Di Modugno, Francesca; Pino, Maria Simona; Nuzzo, Carmen; Cognetti, Francesco; Novelli, Francesco; Nistico, Paola; Milella, Michele

    2012-06-01

    Pancreatic cancer remains a formidable challenge for oncologists and patients alike. Despite intensive efforts, attempts at improving survival in the past 15 years, particularly in advanced disease, have failed. This is true even with the introduction of molecularly targeted agents, chosen on the basis of their action on pathways that were supposedly important in pancreatic cancer development and progression: indeed, with the notable exception of the epidermal growth factor receptor (EGFR) inhibitor erlotinib, that has provided a minimal survival improvement when added to gemcitabine, other agents targeting EGFR, matrix metallo-proteases, farnesyl transferase, or vascular endothelial growth factor have not succeeded in improving outcomes over standard gemcitabine monotherapy for a variety of different reasons. However, recent developments in the molecular epidemiology of pancreatic cancer and an ever evolving understanding of the molecular mechanisms underlying pancreatic cancer initiation and progression raise renewed hope to find novel, relevant therapeutic targets that could be pursued in the clinical setting. In this review we focus on molecular epidemiology of pancreatic cancer, epithelial-to-mesenchymal transition and its influence on sensitivity to EGFR-targeted approaches, apoptotic pathways, hypoxia-related pathways, developmental pathways (such as the hedgehog and Notch pathways), and proteomic analysis as keys to a better understanding of pancreatic cancer biology and, most importantly, as a source of novel molecular targets to be exploited therapeutically.

  11. [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.

  12. MOLECULAR PROGNOSTIC MARKERS OF URINE BLADDER CANCER

    Directory of Open Access Journals (Sweden)

    V. N. Pavlov

    2012-01-01

    Full Text Available Bladder cancer (BC remains a current problem in oncourology. Despite that bladder cancer risk factors have been studied and described in the literature, new molecular and genetic mechanisms have been identified that predisposes to the disease development. There are numerous cellular processes involve in BC pathogenesis. The less-aggressive, non-invasive slow progressing bladder cancer types are defined by Ras-MAPK system activation. Tumors that are more aggressive and have low cancer-specific survival rate are characterized by changes in retinoblastoma genes and p53. Attempts are made to develop prognostic tests to predict tumor behavior, targeted treatment. perspectively, BC patients will be treated using molecular genetic markers allowing the accurate prediction of the patient’s tumor behavior and fitting the treatment tactics on the individual basis.

  13. 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.

  14. Molecular therapeutics in pancreas cancer

    Institute of Scientific and Technical Information of China (English)

    Vignesh Narayanan; Colin D Weekes

    2016-01-01

    The emergence of the "precision-medicine" paradigm in oncology has ushered in tremendous improvements in patient outcomes in a wide variety of malignancies. However, pancreas ductal adenocarcinoma(PDAC) has remained an obstinate challenge to the oncology community and continues to be associated with a dismal prognosis with 5-year survival rates consistently less than 5%. Cytotoxic chemotherapy with gemcitabine-based regimens has been the cornerstone of treatment in PDAC especially because most patients present with inoperable disease. But in recent years remarkable basic science research has improved our understanding of the molecular and genetic basis of PDAC. Whole genomic analysis has exemplified the genetic heterogeneity of pancreas cancer and has led to ingenious efforts to target oncogenes and their downstream signaling cascades. Novel stromal depletion strategies have been devised based on our enhanced recognition of the complex architecture of the tumor stroma and the various mechanisms in the tumor microenvironment that sustain tumorigenesis. Immunotherapy using vaccines and immune checkpoint inhibitors has also risen to the forefront of therapeutic strategies against PDAC. Furthermore, adoptive T cell transfer and strategies to target epigenetic regulators are being explored with enthusiasm. This review will focus on the recent advances in molecularly targeted therapies in PDAC and offer future perspectives to tackle this lethal disease.

  15. Molecular mechanisms of paclitaxel and NM-3 on human gastric cancer in a severe combined immune deficiency mice orthotopic implantation model

    Institute of Scientific and Technical Information of China (English)

    Jin-Shui Zhu; Ming-Quan Song; Guo-Qiang Chen; Qin Li; Qun Sun; Qiang Zhang

    2007-01-01

    AIM: To explore the molecular mechanisms of action of paclitaxel and NM-3 on human gastric cancer in severe combined immune deficiency (SCID) mice.METHODS: Human gastric cancer cells SGC-7901 were implanted into SCID mice and mice were treated with paclitaxel and NM-3. The effects of paclitaxel and NM-3 on apoptosis of human gastric cancer cells were analyzed using flow cytometry, TUNEL assays, and DNA fragment analyses.RESULTS: Apoptosis of SGC-7901 cells was successfully induced by paclitaxel, NM-3, and the combination of paclitaxel and NM-3 24 h after injection as shown by the presence of apoptotic hypodiploid peaks on the flow cytometer before G1-S and a characteristic apoptotic band pattern in the DNA electrophoresis. The apoptotic rate detected by TUNEL assay was found to be significantly higher in the paclitaxel/NM-3 compared to the control group (38.5% ± 5.14% vs 13.2% ± 1.75%,P < 0.01).CONCLUSION: Paclitaxel in combination with NM-3 is able to induce apoptosis of the human gastric cancer cells in SCID mice effectively and synergistically.

  16. Understanding the molecular mechanisms of cancer prevention by dietary phytochemicals:From experimental models to clinical trials

    Institute of Scientific and Technical Information of China (English)

    Girish B Maru; Rasika R Hudlikar; Gaurav Kumar; Khushboo Gandhi; Manoj B Mahimkar

    2016-01-01

    Chemoprevention is one of the cancer prevention approaches wherein natural/synthetic agent(s) are prescribed with the aim to delay or disrupt multiple pathways and processes involved at multiple steps, i.e., initiation, promotion, and progression of cancer. Amongst environmental chemopreventive compounds, diet/beverage-derived components are under evaluation, because of their long history of exposure to humans, high tolerability, low toxicity, and reported biological activities. This compilation briefly covers and compares the available evidence on chemopreventive efficacy and probable mechanism of chemoprevention by selected dietary phytochemicals(capsaicin, curcumin, diallyl sulphide, genistein, green/black tea polyphenols, indoles, lycopene, phenethyl isocyanate, resveratrol, retinoids and tocopherols) in experimental systems and clinical trials. All the dietary phytochemicals covered in this review have demonstrated chemopreventive efficacy against spontaneous or carcinogen-induced experimental tumors and/or associated biomarkers and processes in rodents at several organ sites. The observed anti-initiating, anti-promoting and anti-progression activity of dietary phytochemicals in carcinogen-induced experimental models involve phytochemical-mediated redox changes, modulation of enzymes and signaling kinases resulting to effects on multiple genes and cell signaling pathways. Results from clinical trials using these compounds have not shown them to be chemopreventive. This may be due to our:(1) inability to reproduce the exposure conditions, i.e., levels, complexity, other host and lifestyle factors; and(2) lack of understanding about the mechanisms of action and agent-mediated toxicity in several organs and physiological processes in the host. Current research efforts in addressing the issues of exposure conditions, bioavailability, toxicity and the mode of action of dietary phytochemicals may help address the reason for observed mismatch that may ultimately lead

  17. Molecular imaging in cancer treatment

    Energy Technology Data Exchange (ETDEWEB)

    Michalski, Mark H. [Stanford University School of Medicine, Stanford, CA (United States); Chen, Xiaoyuan [National Institutes of Health (NIH), Laboratory of Molecular Imaging and Nanomedicine (LOMIN), National Institute of Biomedical Imaging and Bioengineering (NIBIB), Bethesda, MD (United States)

    2011-02-15

    The success of cancer therapy can be difficult to predict, as its efficacy is often predicated upon characteristics of the cancer, treatment, and individual that are not fully understood or are difficult to ascertain. Monitoring the response of disease to treatment is therefore essential and has traditionally been characterized by changes in tumor volume. However, in many instances, this singular measure is insufficient for predicting treatment effects on patient survival. Molecular imaging allows repeated in vivo measurement of many critical molecular features of neoplasm, such as metabolism, proliferation, angiogenesis, hypoxia, and apoptosis, which can be employed for monitoring therapeutic response. In this review, we examine the current methods for evaluating response to treatment and provide an overview of emerging PET molecular imaging methods that will help guide future cancer therapies. (orig.)

  18. Molecular mechanisms of meditation.

    Science.gov (United States)

    Jindal, Vishal; Gupta, Sorab; Das, Ritwik

    2013-12-01

    Meditation is a complex process involving change in cognition, memory, and social and emotional control, and causes improvement in various cardiovascular, neurological, autoimmune, and renal pathologies. Meditation also become widely used in medical and psychological treatment therapies for stress-related physical and mental disorders. But still, biological mechanisms in terms of effect on brain and body are poorly understood. This paper explains the basic changes due to meditation in cerebral cortex, prefrontal area, cingulate gyrus, neurotransmitters, white matter, autonomic nervous system, limbic system, cytokines, endorphins, hormones, etc. The following is a review of the current literature regarding the various neurophysiological mechanisms, neuro-endocrine mechanisms, neurochemical substrates, etc. that underlies the complex processes of meditation.

  19. Preliminary research on regulatory effect of estrogen on malignant biological behaviors of triple-negative breast cancer cells and its molecular mechanisms

    Institute of Scientific and Technical Information of China (English)

    Tian-Fang Zhou

    2016-01-01

    Objective:To study the regulating effect of estrogen on malignant biological behaviors of triple-negative breast cancer cells and its molecular mechanisms. Methods:Triple-negative breast cancer cell lines MDA-MB-468 were cultured and treated with different doses of estrogen and 10-6 mol/L estrogen combined with GPR30 antagonist G15 for 12 h, 24 h and 48 h, and then cell viability, migration as well as mRNA expression levels of ITGβ1, Sema 4D, MK, c-Met and AEG-1 were detected. Results:Estradiol could increase cell viability, reduce scratch area and increase mRNA expression levels of ITGβ1, Sema 4D, MK, c-Met and AEG-1 in dose-dependent and time-dependent manner;after estradiol combined with G15 treatment, cell viability was significantly lower than that of estradiol treatment alone, scratch area was significantly larger than that of estradiol treatment alone, and mRNA contents of ITGβ1, Sema 4D, MK, c-Met and AEG-1 were significantly lower than those of estradiol treatment alone. Conclusion:Estrogen can regulate the malignant biological behaviors of triple-negative breast cancer cells, promote cell proliferation and migration, and increase the expression of related genes through GPR30.

  20. Construction and application of a lung cancer stem cell model: antitumor drug screening and molecular mechanism of the inhibitory effects of sanguinarine.

    Science.gov (United States)

    Yang, Jia; Fang, Zhihong; Wu, Jianchun; Yin, Xiaoling; Fang, Yuan; Zhao, Fanchen; Zhu, Shiguo; Li, Yan

    2016-10-01

    Lung cancer is a neoplasm with a 5-year survival rate of less than 15 % and a leading cause of death worldwide, despite recent progress in treatment and diagnostic methods. Lung cancer stem-like cells (CSCs) are pivotal in lung cancer metastasis and drug resistance. This study aimed to develop lung CSCs that stably express stem cell properties through transfection to further screen traditional Chinese herbal compounds. Lung adenocarcinoma stem cells, which include various phenotypic subgroups, are normally characterized by high expression levels of pluripotent stem cell genes, particularly Nanog and OCT4. Plasmids containing Nanog and OCT4 were constructed and transfected into cells, and lung CSCs were identified not only in vitro using RT-PCR, Western blotting, plate cloning, sphere formation, drug resistance, and transwell migration but also in vivo using a nude mouse tumorigenicity assay. Subsequently, sanguinarine, which is derived from the whole leaves of the traditional Chinese medicine celandine, was identified through the high-throughput screening of a small-molecule compound library. Investigation of the molecular mechanisms of the effects of sanguinarine revealed that it significantly inhibited lung CSC proliferation, invasion, and apoptosis, possibly via downregulation of the Wnt/β-catenin signaling pathway. Our results indicate that lung CSCs established by gene transfection may provide a stable and effective method of constructing CSCs to effectively screen potential antitumor drugs. Furthermore, these results suggest that sanguinarine may be a natural antitumor compound that targets lung CSCs, laying a foundation for further clinical study.

  1. Molecular mechanisms in gliomagenesis

    DEFF Research Database (Denmark)

    Hulleman, Esther; Helin, Kristian

    2005-01-01

    brain development, such as the differentiation of neural stem cells (NSCs) into astrocytes, might contribute to GBM formation. These pathways include growth factor-induced signal transduction routes and processes that control cell cycle progression, such as the p16-CDK4-RB and the ARF-MDM2-p53 pathways....... The expression of several of the components of these signaling cascades has been found altered in GBM, and recent data indicate that combinations of mutations in these pathways may contribute to GBM formation, although the exact mechanisms are still to be uncovered. Use of novel techniques including large...

  2. Molecular Mechanisms of Parturition

    Directory of Open Access Journals (Sweden)

    F. Ferré

    1997-01-01

    Full Text Available The initial signal for triggering human parturition might be fetal but of trophoblastic origin. Concomitantly, this placental signal would have as its target not only the uterus but also the fetus by activating its hypothalamo-pituitary-adrenocortical axis. The latter would represent a second fetal signal which, at the fetomaternal interface, would amplify and define in time the mechanisms responsible for the onset of labor, implying changes in the myometrial and cervical extracellular matrix associated with the accession of the contractile phenotype for myometrial cells. At each phase of these processes in the utero-feto-placental system, the nature of these signals remains to be identified. Is there a single substance, or rather, and more likely, a combination of several?

  3. Molecular mechanisms of rosacea pathogenesis

    Directory of Open Access Journals (Sweden)

    Davydova A.M.

    2013-09-01

    Full Text Available The article presents possible molecular mechanisms for rosacea pathogenesis from current domestic and foreign clinical observations and laboratory research: regulation and expression defects of antimicrobial peptides, vascular endothelial growth factor, the effect of serine proteases, oxidative stress, reactive oxygen species and ferritin on the occurrence and course of rosacea. New developments in molecular biology and genetics are advanced for researching the interaction of multiple factors involved in rosacea pathogenesis, as well as providing the bases for potentially new therapies.

  4. Molecular mechanisms and clinical applications of miR-22 in regulating malignant progression in human cancer (Review)

    Science.gov (United States)

    Wang, Jingyu; Li, Yuan; Ding, Meiman; Zhang, Honghe; Xu, Xiaoming; Tang, Jinlong

    2017-01-01

    miRNAs (microRNAs) have been validated to play fateful roles in the occurrence and development of cancers by post-transcriptionally targeting 3′-untranslated regions of the downstream gene mRNAs to repress mRNA expression. Mounting investigations forcefully document that not only does miR-22 biologically impinge on the processes of senescence, energy supply, angiogenesis, EMT (epithelial-mesenchymal transition), proliferation, migration, invasion, metastasis and apoptosis, but also it genetically or epigenetically exerts dual (inhibitory/promoting cancer) effects in various cancers via CNAs (copy number alterations), SNPs (single nucleotide polymorphisms), methylation, acetylation and even more momentously hydroxymethylation. Additionally, miR-22 expression may fluctuate with cancer progression in the body fluids of cancer patients and miR-22 could amplify its inhibitory or promoting effects through partaking in positive or negative feedback loops and interplaying with many other related miRNAs in the cascade of events, making it possible for miR-22 to be a promising and complementary or even independent cancer biomarker in some cancers and engendering profound influences on the early diagnosis, therapeutics, supervising curative effects and prognosis. PMID:28000852

  5. Molecular Testing for Gastrointestinal Cancer

    Science.gov (United States)

    Lee, Hye Seung; Kim, Woo Ho; Kwak, Yoonjin; Koh, Jiwon; Bae, Jeong Mo; Kim, Kyoung-Mee; Chang, Mee Soo; Han, Hye Seung; Kim, Joon Mee; Kim, Hwal Woong; Chang, Hee Kyung; Choi, Young Hee; Park, Ji Y.; Gu, Mi Jin; Lhee, Min Jin; Kim, Jung Yeon; Kim, Hee Sung; Cho, Mee-Yon

    2017-01-01

    With recent advances in molecular diagnostic methods and targeted cancer therapies, several molecular tests have been recommended for gastric cancer (GC) and colorectal cancer (CRC). Microsatellite instability analysis of gastrointestinal cancers is performed to screen for Lynch syndrome, predict favorable prognosis, and screen patients for immunotherapy. The epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor has been approved in metastatic CRCs with wildtype RAS (KRAS and NRAS exon 2–4). A BRAF mutation is required for predicting poor prognosis. Additionally, amplification of human epidermal growth factor receptor 2 (HER2) and MET is also associated with resistance to EGFR inhibitor in metastatic CRC patients. The BRAF V600E mutation is found in sporadic microsatellite unstable CRCs, and thus is helpful for ruling out Lynch syndrome. In addition, the KRAS mutation is a prognostic biomarker and the PIK3CA mutation is a molecular biomarker predicting response to phosphoinositide 3-kinase/AKT/mammalian target of rapamycin inhibitors and response to aspirin therapy in CRC patients. Additionally, HER2 testing should be performed in all recurrent or metastatic GCs. If the results of HER2 immunohistochemistry are equivocal, HER2 silver or fluorescence in situ hybridization testing are essential for confirmative determination of HER2 status. Epstein-Barr virus–positive GCs have distinct characteristics, including heavy lymphoid stroma, hypermethylation phenotype, and high expression of immune modulators. Recent advances in next-generation sequencing technologies enable us to examine various genetic alterations using a single test. Pathologists play a crucial role in ensuring reliable molecular testing and they should also take an integral role between molecular laboratories and clinicians. PMID:28219002

  6. Molecular Imaging of Prostate Cancer: A Concise Synopsis

    Directory of Open Access Journals (Sweden)

    Hossein Jadvar

    2009-03-01

    Full Text Available Prostate cancer is the most common malignancy in men and continues to be a major public health problem. Imaging of prostate cancer remains particularly challenging owing to disease heterogeneity. Molecular imaging can provide unprecedented opportunities for deciphering the molecular mechanisms that are involved in the development and natural progression of prostate cancer from a localized process to the hormone-refractory metastatic disease. Such understanding will be the key for targeted imaging and therapy and for predicting and evaluating treatment response and prognosis. In this article, we review briefly the contribution of multimodality molecular imaging methods for the in vivo characterization of the pathophysiology of prostate cancer.

  7. The Molecular Mechanism of the Supra-Additive Response of Prostate Cancer to Androgen Ablation and Radiotherapy

    Science.gov (United States)

    2001-02-01

    months, 6 months, 1 year and 2 years after completion of treatment. In addition, a more specific questionaire designed to assess radiotherapy sexual ... Health and Human Services; Grant numbers: CA 06294, CA 16672; Grant sponsor: DOD; Grant number: DAMD 17-98-1-8483; Grant sponsor: Prostate Cancer...16672 awarded construct (Ad5-p53). A key question was whether Ad5-p53 by the National Cancer Institute, United States Department of Health and Human

  8. [Molecular diagnostics of lung cancer].

    Science.gov (United States)

    Ryska, A; Dziadziuszko, R; Olszewski, W; Berzinec, P; Öz, B; Gottfried, M; Cufer, T; Samarzija, M; Plank, L; Ostoros, Gy; Tímár, J

    2015-09-01

    Development of the target therapies of lung cancer was a rapid process which fundamentally changed the pathological diagnosis as well. Furthermore, molecular pathology became essential part of the routine diagnostics of lung cancer. These changes generated several practical problems and in underdeveloped countries or in those with reimbursement problems have been combined with further challenges. The central and eastern region of Europe are characterized by similar problems in this respect which promoted the foundation of NSCLC Working Group to provide up to date protocols or guidelines. This present paper is a summary of the molecular pathology and target therapy guidelines written with the notion that it has to be upgraded continuously according to the development of the field.

  9. Molecular mechanisms underlying bacterial persisters

    DEFF Research Database (Denmark)

    Maisonneuve, Etienne; Gerdes, Kenn

    2014-01-01

    All bacteria form persisters, cells that are multidrug tolerant and therefore able to survive antibiotic treatment. Due to the low frequencies of persisters in growing bacterial cultures and the complex underlying molecular mechanisms, the phenomenon has been challenging to study. However, recent...

  10. STATINS AND MYOPATHY: MOLECULAR MECHANISMS

    Directory of Open Access Journals (Sweden)

    O. M. Drapkina

    2012-01-01

    Full Text Available The safety of statin therapy is considered. In particular the reasons of a complication such as myopathy are discussed in detail. The molecular mechanisms of statin myopathy , as well as its risk factors are presented. The role of coenzyme Q10 in the myopathy development and coenzyme Q10 application for the prevention of this complication are considered. 

  11. Molecular Mechanism of Local Drug Delivery with Paclitaxel-Eluting Membranes in Biliary and Pancreatic Cancer: New Application for an Old Drug

    Directory of Open Access Journals (Sweden)

    Sookhee Bang

    2015-01-01

    Full Text Available Implantation of self-expanding metal stents (SEMS is palliation for patients suffering from inoperable malignant obstructions associated with biliary and pancreatic cancers. Chemotherapeutic agent-eluting stents have been developed because SEMS are susceptible to occlusion by tumor in-growth. We reported recently that paclitaxel-eluting SEMS provide enhanced local drug delivery in an animal model. However, little is known about the molecular mechanisms by which paclitaxel-eluting stents attenuate tumor growth. We investigated the signal transduction pathways underlying the antiproliferative effects of a paclitaxel-eluting membrane (PEM implanted in pancreatic/cholangiocarcinoma tumor bearing nude mice. Molecular and cellular alterations were analyzed in the PEM-implanted pancreatic/cholangiocarcinoma xenograft tumors by Western blot, immunoprecipitation, and immunofluorescence. The quantities of paclitaxel released into the tumor and plasma were determined by liquid chromatography-tandem mass spectroscopy. Paclitaxel from the PEM and its diffusion into the tumor inhibited angiogenesis, which involved suppression of mammalian target of rapamycin (mTOR through regulation of hypoxia inducible factor (HIF-1 and increased apoptosis. Moreover, implantation of the PEM inhibited tumor-stromal interaction-related expression of proteins such as CD44, SPARC, matrix metalloproteinase-2, and vimentin. Local delivery of paclitaxel from a PEM inhibited growth of pancreatic/cholangiocarcinoma tumors in nude mice by suppressing angiogenesis via the mTOR and inducing apoptosis signal pathway.

  12. Study of molecular mechanisms of pro-apoptotic activity of NCX 4040, a novel nitric oxide-releasing aspirin, in colon cancer cell lines

    Directory of Open Access Journals (Sweden)

    Vannini Ivan

    2007-10-01

    Full Text Available Abstract Background Despite numerous studies aimed at verifying the antitumor activity of nitric oxide-releasing nonsteroidal antiflammatory drugs (NO-NSAIDs, little is known about the molecular targets responsible for their antineoplastic properties. In the present study, we investigated the mechanisms underlying the cytotoxicity of NCX 4040, a novel NO-aspirin with promising antineoplastic action, in in vitro human colon cancer models. Methods The effect on tumor growth was evaluated in four human colon cancer cell lines (LoVo, LRWZ, WiDr and LoVo Dx by sulforhodamine B assay, oxidative stress by immunohistochemistry, apoptosis by laddering assay, mitochondrial membrane potential (ΔΨm by flow cytometry, and apoptosis- and chemoresistance-related markers by western-blot and real-time method, respectively. Prostaglandin E2 levels were determined by ELISA. Results NCX 4040 produced a higher cytotoxic effect in all the cell lines than that produced by other NO donors tested. In particular, in LoVo and LRWZ cells, NCX 4040 induced a cytocidal effect and apoptosis through p53 and NAG-1 expression, an early ΔΨm collapse, and a sequential release of cytoplasmatic cytochrome c and caspase -9 and -3 active forms. 8-hydroxyguanine lesions, indicative of oxidative stress, were also observed. Conversely, in WiDr line, the drug caused a cytocidal effect, albeit not through apoptosis, and a concomitant increase in COX-2 activity. In LoVo Dx line, characterized by high levels drug resistance and DNA repair-related markers, only a cytostatic effect was observed, again in concomitance with the increase in COX-2 enzyme activity. Conclusion This study highlights the multiplicity of mechanisms involved in sensitivity or resistance to NCX 4040 and could provide useful indications for tailored therapy by identifying potentially drug-responsive tumors.

  13. Molecular mechanisms for inhibition of colon cancer cells by combined epigenetic-modulating epigallocatechin gallate and sodium butyrate

    OpenAIRE

    Sabita N. Saldanha; Kala, Rishabh; Tollefsbol, Trygve O.

    2014-01-01

    Bioactive compounds are considered safe and have been shown to alter genetic and epigenetic profiles of tumor cells. However, many of these changes have been reported at molecular concentrations higher than physiologically achievable levels. We investigated the role of the combinatorial effects of epigallocatechin gallate (EGCG), a predominant polyphenol in green tea, and sodium butyrate (NaB), a dietary microbial fermentation product of fiber, in the regulation of survivin, which is an overe...

  14. Molecular mechanism underlying the antiproliferative effect of suppressor of cytokine signaling-1 in non-small-cell lung cancer cells.

    Science.gov (United States)

    Shimada, Kazuki; Serada, Satoshi; Fujimoto, Minoru; Nomura, Shintaro; Nakatsuka, Rie; Harada, Emi; Iwahori, Kota; Tachibana, Isao; Takahashi, Tsuyoshi; Kumanogoh, Atsushi; Kishimoto, Tadamitsu; Naka, Tetsuji

    2013-11-01

    Lung cancer (LC) is the major cause of death by cancer and the number of LC patients is increasing worldwide. This study investigated the therapeutic potential of gene delivery using suppressor of cytokine signaling 1 (SOCS-1), an endogenous inhibitor of intracellular signaling pathways, for the treatment of LC. To examine the antitumor effect of SOCS-1 overexpression on non-small-cell lung cancer (NSCLC) cells, NSCLC cells (A549, LU65, and PC9) were infected with adenovirus-expressing SOCS-1 vector. The cell proliferation assay showed that A549 and LU65, but not PC9, were sensitive to SOCS-1 gene-mediated suppression of cell growth. Although JAK inhibitor I could also inhibit proliferation of A549 and LU65 cells, SOCS-1 gene delivery appeared to be more potent as SOCS-1 could suppress focal adhesion kinase and epidermal growth factor receptor, as well as the JAK/STAT3 signaling pathway. Enhanced phosphorylation of the p53 protein was detected by means of phospho-kinase array in SOCS-1 overexpressed A549 cells compared with control cells, whereas no phosphorylation of p53 was observed when JAK inhibitor I was used. Furthermore, treatment with adenoviral vector AdSOCS-1 in vivo significantly suppressed NSCLC proliferation in a xenograft model. These results suggest that the overexpression of SOCS-1 gene is effective for antitumor therapy by suppressing the JAK/STAT, focal adhesion kinase, and epidermal growth factor receptor signaling pathways and enhancing p53-mediated antitumor activity in NSCLC.

  15. Genetics and molecular biology of breast cancer

    Energy Technology Data Exchange (ETDEWEB)

    King, M.C. [California Univ., Berkeley, CA (United States); Lippman, M. [Georgetown Univ. Medical Center, Washington, DC (United States)] [comps.

    1992-12-31

    This volume contains the abstracts of oral presentations and poster sessions presented at the Cold Springs Harbor Meeting on Cancer Cells, this meeting entitled Genetics and Molecular Biology of Breast Cancer.

  16. Effects of miR-424 on Proliferation and Migration Abilities in Non-small Cell Lung Cancer A549 Cells and Its Molecular Mechanism

    Directory of Open Access Journals (Sweden)

    Hongmin LI

    2016-09-01

    Full Text Available Background and objective The inhibitory ability of miR-424 on the proliferation of renal carcinoma cell and the migration and invasion of cancer cells has been widely explored and demonstrated. However, the effects of miR-424 on non-small cell lung cancer (NSCLC have not been systematically examined. In this study, detected the growth and invasion effect of miR-424 in NSCLC A549 cell. The migration and molecular mechanism of this cell are also detected. Methods NSCLC A549 cell was transfected with miR-424 and its inhibitor. After transfection, the proliferation ability of A549 cell was detectedby CCK8 assay. Then, the migration ability in A549 cell was detected by migration assays. Furthermore, the expression level of MMP2 and MMP9 in A549 was detected by Western blot and immune fluorescence. The 3'UTR of E2F6 was cloned into luciferase reporter vector and its enzymatic activitywas detected to verify whether miR-424 can target E2F6. The expression level of E2F6 in a549 cell after transfecing with miR-424 was detected by Western blot. Results After transfection of miR-424, the proliferation and migration abilities were remarkably decreased and the expression level of MMP-2 and MMP-9 were down-regulated in A549. Moreover, MiR-424 inhibited the enzymatic activity of luviferase reporter vector of E2F6. Specifically, the expression level of E2F6 was down-regulated in A549. Conclusion miR-424 can inhibit the proliferation and migration abilities of A549 by negatively regulating the expression of E2F6.

  17. Superspreading: mechanisms and molecular design.

    Science.gov (United States)

    Theodorakis, Panagiotis E; Müller, Erich A; Craster, Richard V; Matar, Omar K

    2015-03-03

    The intriguing ability of certain surfactant molecules to drive the superspreading of liquids to complete wetting on hydrophobic substrates is central to numerous applications that range from coating flow technology to enhanced oil recovery. Despite significant experimental efforts, the precise mechanisms underlying superspreading remain unknown to date. Here, we isolate these mechanisms by analyzing coarse-grained molecular dynamics simulations of surfactant molecules of varying molecular architecture and substrate affinity. We observe that for superspreading to occur, two key conditions must be simultaneously satisfied: the adsorption of surfactants from the liquid-vapor surface onto the three-phase contact line augmented by local bilayer formation. Crucially, this must be coordinated with the rapid replenishment of liquid-vapor and solid-liquid interfaces with surfactants from the interior of the droplet. This article also highlights and explores the differences between superspreading and conventional surfactants, paving the way for the design of molecular architectures tailored specifically for applications that rely on the control of wetting.

  18. Fernblock (Polypodium leucotomos Extract: Molecular Mechanisms and Pleiotropic Effects in Light-Related Skin Conditions, Photoaging and Skin Cancers, a Review

    Directory of Open Access Journals (Sweden)

    Concepcion Parrado

    2016-06-01

    Full Text Available Healthier life styles include increased outdoors time practicing sports and walking. This means increased exposure to the sun, leading to higher risk of sunburn, photoaging and skin cancer. In addition to topical barrier products, oral supplementations of various botanicals endowed with antioxidant activity are emerging as novel method of photoprotection. Polypodium leucotomos extract (PL, commercial name Fernblock®, IFC Group, Spain is a powerful antioxidant due to its high content of phenolic compounds. PL is administered orally, with proven safety, and it can also be used topically. Its mechanisms include inhibition of the generation and release of reactive oxygen species (ROS by ultraviolet (UV light. It also prevents UV- and ROS-induced DNA damage with inhibition of AP1 and NF-κB and protection of natural antioxidant enzyme systems. At the cellular level, PL decreases cellular apoptosis and necrosis mediated UV and inhibits abnormal extracellular matrix remodeling. PL reduces inflammation, prevents immunosuppression, activates tumor suppressor p53 and inhibits UV-induced cyclooxygenase-2 (COX-2 enzyme expression. In agreement with increased p53 activity, PL decreased UV radiation-induced cell proliferation. PL also prevents common deletions mitochondrial DNA damage induced by UVA, and MMP-1 expression induced Visible Light and Infrared Radiation. These cellular and molecular effects are reflected in inhibitions of carcinogenesis and photoaging.

  19. Cancer and molecular biomarkers of phase 2

    DEFF Research Database (Denmark)

    Dalhoff, Kim; Enghusen Poulsen, Henrik

    2005-01-01

    as molecular genetic biomarkers of risk. GSTM(my)1 has been associated with an increased risk of colorectal cancer, lung cancer, and bladder cancer and GSTP(pi)1 with prostate cancer. UGT1A1*28 and *37 are both associated with an increased risk of breast cancer as is SULT1A1*2. The presence of UGT1A1...

  20. [Molecular bases of cancer immunology].

    Science.gov (United States)

    Barrera-Rodríguez, R; Peralta-Zaragoza, O; Madrid-Marina, V

    1995-01-01

    The immune system is a tight network of different types of cells and molecules. The coordinated action of these elements mounts a precise immune response against tumor cells. However, these cells present several escape mechanisms, leading to tumor progression. This paper shows several cellular and molecular events involved in the regulation of the immune response against tumor cells. The interaction of several molecules such as MHC, TcR, adhesins, tumor antigens and cytokines are discussed, as well as the most recent knowledge about escape mechanisms and immunotherapy.

  1. Epigenetic mechanisms in gastric cancer.

    Science.gov (United States)

    Gigek, Carolina Oliveira; Chen, Elizabeth Suchi; Calcagno, Danielle Queiroz; Wisnieski, Fernanda; Burbano, Rommel Rodriguez; Smith, Marilia Arruda Cardoso

    2012-06-01

    Cancer is considered one of the major health issues worldwide, and gastric cancer accounted for 8% of total cases and 10% of total deaths in 2008. Gastric cancer is considered an age-related disease, and the total number of newly diagnosed cases has been increasing as a result of the higher life expectancy. Therefore, the basic mechanisms underlying gastric tumorigenesis is worth investigation. This review provides an overview of the epigenetic mechanisms, such as DNA methylation, histone modifications, chromatin remodeling complex and miRNA, involved in gastric cancer. As the studies in gastric cancer continue, the mapping of an epigenome code is not far for this disease. In conclusion, an epigenetic therapy might appear in the not too distant future.

  2. Molecular Mechanism of Somite Development

    Directory of Open Access Journals (Sweden)

    Gulfidan Coskun

    2013-06-01

    Full Text Available From third week of gestation, notochord and the neural folds begin to gather at the center of the embryo to form the paraxial mesoderm. Paraxial mesoderm separates into blocks of cells called somitomers at the lateral sides of the neural tube of the head region. At the beginning of the third week somitomeres take ring shapes and form blocks of somites from occipital region to caudal region. Although somites are transient structures, they are extremely important in organizing the segmental pattern of vertebrate embryos. Somites give rise to the cells that form the vertebrae and ribs, the dermis of the dorsal skin, the skeletal muscles of the back, and the skeletal muscles of the body wall and limbs. Somitogenesis are formed by a genetic mechanism that is regulated by cyclical expression of genes in the Notch, Wnt and fibroblast growth factor signaling pathways. The prevailing model of the mechanism governing somitogenesis is the “clock and wave front”. Somitogenesis has components of periodicity, separation, epithelialization and axial specification. According to this model, the clock causes cells to undergo repeated oscillations, with a particular phase of each oscillation defining the competency of cells in the presomitic mesoderm to form a somite. Any disruption in this mechanism can be cause of severe segmentation defects of the vertebrae and congenital anomalies. In this review, we discuss the molecular mechanisms underlying the somitogenesis which is an important part of morphogenesis. [Archives Medical Review Journal 2013; 22(3.000: 362-376

  3. Molecular Mechanisms Underlying Hepatocellular Carcinoma

    Directory of Open Access Journals (Sweden)

    Christian Trepo

    2009-11-01

    Full Text Available Hepatocarcinogenesis is a complex process that remains still partly understood. That might be explained by the multiplicity of etiologic factors, the genetic/epigenetic heterogeneity of tumors bulks and the ignorance of the liver cell types that give rise to tumorigenic cells that have stem cell-like properties. The DNA stress induced by hepatocyte turnover, inflammation and maybe early oncogenic pathway activation and sometimes viral factors, leads to DNA damage response which activates the key tumor suppressive checkpoints p53/p21Cip1 and p16INK4a/pRb responsible of cell cycle arrest and cellular senescence as reflected by the cirrhosis stage. Still obscure mechanisms, but maybe involving the Wnt signaling and Twist proteins, would allow pre-senescent hepatocytes to bypass senescence, acquire immortality by telomerase reactivation and get the last genetic/epigenetic hits necessary for cancerous transformation. Among some of the oncogenic pathways that might play key driving roles in hepatocarcinogenesis, c-myc and the Wnt/β-catenin signaling seem of particular interest. Finally, antiproliferative and apoptosis deficiencies involving TGF-β, Akt/PTEN, IGF2 pathways for instance are prerequisite for cancerous transformation. Of evidence, not only the transformed liver cell per se but the facilitating microenvironment is of fundamental importance for tumor bulk growth and metastasis.

  4. Molecular Diagnostic Applications in Colorectal Cancer

    Directory of Open Access Journals (Sweden)

    Laura Huth

    2014-06-01

    Full Text Available Colorectal cancer, a clinically diverse disease, is a leading cause of cancer-related death worldwide. Application of novel molecular diagnostic tests, which are summarized in this article, may lead to an improved survival of colorectal cancer patients.  Distinction of these applications is based on the different molecular principles found in colorectal cancer (CRC. Strategies for molecular analysis of single genes (as KRAS or TP53 as well as microarray based techniques are discussed. Moreover, in addition to the fecal occult blood testing (FOBT and colonoscopy some novel assays offer approaches for early detection of colorectal cancer like the multitarget stool DNA test or the blood-based Septin 9 DNA methylation test. Liquid biopsy analysis may also exhibit great diagnostic potential in CRC for monitoring developing resistance to treatment. These new diagnostic tools and the definition of molecular biomarkers in CRC will improve early detection and targeted therapy of colorectal cancer.

  5. Molecular Mechanisms Behind the Chemopreventive Effects of Anthocyanidins

    Directory of Open Access Journals (Sweden)

    De-Xing Hou

    2004-01-01

    Full Text Available Anthocyanins are polyphenolic ring-based flavonoids, and are widespread in fruits and vegetables of red-blue color. Epidemiological investigations and animal experiments have indicated that anthocyanins may contribute to cancer chemoprevention. The studies on the mechanism have been done recently at molecular level. This review summarizes current molecular bases for anthocyanidins on several key steps involved in cancer chemoprevention: (i inhibition of anthocyanidins in cell transformation through targeting mitogen-activated protein kinase (MAPK pathway and activator protein 1 (AP-1 factor; (ii suppression of anthocyanidins in inflammation and carcinogenesis through targeting nuclear factor kappa B (NF-κB pathway and cyclooxygenase 2 (COX-2 gene; (iii apoptotic induction of cancer cells by anthocyanidins through reactive oxygen species (ROS / c-Jun NH2-terminal kinase (JNK-mediated caspase activation. These data provide a first molecular view of anthocyanidins contributing to cancer chemoprevention.

  6. Molecular mechanisms of cryptococcal meningitis.

    Science.gov (United States)

    Liu, Tong-Bao; Perlin, David S; Xue, Chaoyang

    2012-01-01

    Fungal meningitis is a serious disease caused by a fungal infection of the central nervous system (CNS) mostly in individuals with immune system deficiencies. Fungal meningitis is often fatal without proper treatment, and the mortality rate remains unacceptably high even with antifungal drug interventions. Currently, cryptococcal meningitis is the most common fungal meningitis in HIV-1/AIDS, and its disease mechanism has been extensively studied. The key steps for fungi to infect brain and cause meningitis after establishment of local infection are the dissemination of fungal cells to the bloodstream and invasion through the blood brain barrier to reach the CNS. In this review, we use cryptococcal CNS infection as an example to describe the current molecular understanding of fungal meningitis, including the establishment of the infection, dissemination, and brain invasion. Host and microbial factors that contribute to these infection steps are also discussed.

  7. Molecular Mechanisms of Bacterial Pathogenicity

    Science.gov (United States)

    Fuchs, Thilo Martin

    Cautious optimism has arisen over recent decades with respect to the long struggle against bacteria, viruses, and parasites. This has been offset, however, by a fatal complacency stemming from previous successes such as the development of antimicrobial drugs, the eradication of smallpox, and global immunization programs. Infectious diseases nevertheless remain the world's leading cause of death, killing at least 17 million persons annually [61]. Diarrheal diseases caused by Vibrio cholerae or Shigella dysenteriae kill about 3 million persons every year, most of them young children: Another 4 million die of tuberculosis or tetanus. Outbreaks of diphtheria in Eastern Europe threatens the population with a disease that had previously seemed to be overcome. Efforts to control infectious diseases more comprehensively are undermined not only by socioeconomic conditions but also by the nature of the pathogenic organisms itself; some isolates of Staphylococcus aureus and Enterobacter have become so resistant to drugs by horizontal gene transfer that they are almost untreatable. In addition, the mechanism of genetic variability helps pathogens to evade the human immune system, thus compromising the development of powerful vaccines. Therefore detailed knowledge of the molecular mechanisms of microbial pathogenicity is absolutely necessary to develop new strategies against infectious diseases and thus to lower their impact on human health and social development.

  8. 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.

  9. Molecular toxicity mechanism of nanosilver

    Directory of Open Access Journals (Sweden)

    Danielle McShan

    2014-03-01

    Full Text Available Silver is an ancient antibiotic that has found many new uses due to its unique properties on the nanoscale. Due to its presence in many consumer products, the toxicity of nanosilver has become a hot topic. This review summarizes recent advances, particularly the molecular mechanism of nanosilver toxicity. The surface of nanosilver can easily be oxidized by O2 and other molecules in the environmental and biological systems leading to the release of Ag+, a known toxic ion. Therefore, nanosilver toxicity is closely related to the release of Ag+. In fact, it is difficult to determine what portion of the toxicity is from the nano-form and what is from the ionic form. The surface oxidation rate is closely related to the nanosilver surface coating, coexisting molecules, especially thiol-containing compounds, lighting conditions, and the interaction of nanosilver with nucleic acids, lipid molecules, and proteins in a biological system. Nanosilver has been shown to penetrate the cell and become internalized. Thus, nanosilver often acts as a source of Ag+ inside the cell. One of the main mechanisms of toxicity is that it causes oxidative stress through the generation of reactive oxygen species and causes damage to cellular components including DNA damage, activation of antioxidant enzymes, depletion of antioxidant molecules (e.g., glutathione, binding and disabling of proteins, and damage to the cell membrane. Several major questions remain to be answered: (1 the toxic contribution from the ionic form versus the nano-form; (2 key enzymes and signaling pathways responsible for the toxicity; and (3 effect of coexisting molecules on the toxicity and its relationship to surface coating.

  10. Molecular imaging of prostate cancer with PET.

    Science.gov (United States)

    Jadvar, Hossein

    2013-10-01

    Molecular imaging is paving the way for precision and personalized medicine. In view of the significant biologic and clinical heterogeneity of prostate cancer, molecular imaging is expected to play an important role in the evaluation of this prevalent disease. The natural history of prostate cancer spans from an indolent localized process to biochemical relapse after radical treatment with curative intent to a lethal castrate-resistant metastatic disease. The ongoing unraveling of the complex tumor biology of prostate cancer uniquely positions molecular imaging with PET to contribute significantly to every clinical phase of prostate cancer evaluation. The purpose of this article was to provide a concise review of the current state of affairs and potential future developments in the diagnostic utility of PET in prostate cancer.

  11. Genetic and molecular changes in ovarian cancer

    Institute of Scientific and Technical Information of China (English)

    Robert L Hollis; Charlie Gourley

    2016-01-01

    Epithelial ovarian cancer represents the most lethal gynecological malignancy in the developed world, and can be divided into five main histological subtypes: high grade serous, endometrioid, clear cell, mucinous and low grade serous. These subtypes represent distinct disease entities, both clinically and at the molecular level. Molecular analysis has revealed significant genetic heterogeneity in ovarian cancer, particularly within the high grade serous subtype. As such, this subtype has been the focus of much research effort to date, revealing molecular subgroups at both the genomic and transcriptomic level that have clinical implications. However, stratification of ovarian cancer patients based on the underlying biology of their disease remains in its infancy. Here, we summarize the molecular changes that characterize the five main ovarian cancer subtypes, highlight potential opportunities for targeted therapeutic intervention and outline priorities for future research.

  12. Molecular Diagnosis in Bladder Cancer

    NARCIS (Netherlands)

    T.C.M. Zuiverloon (Tahlita)

    2013-01-01

    textabstractEpidemiologyBladder cancer (BC) is the most prevalent type of urothelial cancer and is associated with thehighest costs of all cancer types due to intensive patient surveillance. Because bladder tumorsfrequently recur, patients need to be monitored extensively [1-4]. Incidence increases

  13. Molecular imaging of breast cancer

    NARCIS (Netherlands)

    Adams, A.L.L.

    2014-01-01

    Breast cancer is the most common type of cancer in women. Imaging techniques play a pivotal role in breast cancer management, especially in lesion detection, treatment planning and evaluation, and prognostication. These imaging techniques have however limitations such as the use of ionizing radiatio

  14. Experimental therapy of ovarian cancer with synthetic makaluvamine analog: in vitro and in vivo anticancer activity and molecular mechanisms of action.

    Directory of Open Access Journals (Sweden)

    Tao Chen

    Full Text Available The present study was designed to determine the biological effects of novel marine alkaloid analog 7-(4-fluorobenzylamino-1,3,4,8-tetrahydropyrrolo[4,3,2-de]quinolin-8(1H-one (FBA-TPQ on human ovarian cancer cells for its anti-tumor potential and the underlying mechanisms as a novel chemotherapeutic agent. Human ovarian cancer cells (A2780 and OVCAR-3, and Immortalized non-tumorigenic human Ovarian Surface Epithelial cells (IOSE-144, were exposed to FBA-TPQ for initial cytotoxicity evaluation (via MTS assay kit, Promega. The detailed in-vitro (cell level and in-vivo (animal model studies on the antitumor effects and possible underlying mechanisms of action of the compounds were then performed. FBA-TPQ exerted potent cytotoxicity against human ovarian cancer A2780 and OVCAR-3 cells as an effective inhibitor of cell growth and proliferation, while exerting lesser effects on non-tumorigenic IOSE-144 cells. Further study in the more sensitive OVCAR-3 cell line showed that it could potently induce cell apoptosis (Annexin V-FITC assay, G2/M cell cycle arrest (PI staining analysis and also dose-dependently inhibit OVCAR-3 xenograft tumors' growth on female athymic nude mice (BALB/c, nu/nu. Mechanistic studies (both in vitro and in vivo revealed that FBA-TPQ might exert its activity through Reactive Oxygen Species (ROS-associated activation of the death receptor, p53-MDM2, and PI3K-Akt pathways in OVCAR-3 cells, which is in accordance with in vitro microarray (Human genome microarrays, Agilent data analysis (GEO accession number: GSE25317. In conclusion, FBA-TPQ exhibits significant anticancer activity against ovarian cancer cells, with minimal toxicity to non-tumorigenic human IOSE-144 cells, indicating that it may be a potential therapeutic agent for ovarian cancer.

  15. Genitourinary cancers: molecular determinants for personalized therapies.

    Science.gov (United States)

    Mazzucchelli, Roberta; Gasparrini, Silvia; Galosi, Andrea B; Massari, Francesco; Raspollini, Maria Rosaria; Scarpelli, Marina; Lopez-Beltran, Antonio; Cheng, Liang; Montironi, Rodolfo

    2016-09-26

    Recent insights and emerging strategies for individualized therapeutic approaches in patients with genitourinary (GU) cancers are based on patient's genomic and cancer's molecular profiles. This depends on the significant advances made in molecular biology technologies, such as next-generation sequencing and whole-exome sequencing. The rise of such novel techniques has grayly increased our knowledge on cancer cell biology and development, thus allowing to identify complex abnormalities at the genomic level. These findings have paved the way toward what is called precision medicine, thus providing healthcare from an individual perspective in patients with GU tumors.

  16. Molecular mechanisms of synaptic plasticity and memory.

    Science.gov (United States)

    Elgersma, Y; Silva, A J

    1999-04-01

    To unravel the molecular and cellular bases of learning and memory is one of the most ambitious goals of modern science. The progress of recent years has not only brought us closer to understanding the molecular mechanisms underlying stable, long-lasting changes in synaptic strength, but it has also provided further evidence that these mechanisms are required for memory formation.

  17. Exploiting novel molecular targets in gastrointestinal cancers

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Novel molecular targets are being discovered as we learn more about the aberrant processes underlying various cancers. Efforts to translate this knowledge are starting to impact on the care of patients with gastrointestinal cancers. The epidermal growth factor receptor (EGFR) pathway and angiogenesis have been targeted successfully in colorectal cancer with cetuximab, panitunumab and bevacizumab. Similarly, EGFR-targeting with erlotinib yielded significant survival benefit in pancreatic cancer when combined with gemcitabine. The multi-targeting approach with sorafenib has made it the first agent to achieve significant survival benefit in hepatocellular carcinoma. Efforts to exploit the dysregulated Akt/mTOR pathway in GI cancer therapy are ongoing. These molecular targets can be disrupted by various approaches, including the use of monoclonal antibody to intercept extracellular ligands and disrupt receptor-ligand binding, and small molecule inhibitors that interrupt the activation of intracellular kinases.

  18. DNA aptamers as molecular probes for colorectal cancer study.

    Directory of Open Access Journals (Sweden)

    Kwame Sefah

    Full Text Available BACKGROUND: Understanding the molecular features of specific tumors can increase our knowledge about the mechanism(s underlying disease development and progression. This is particularly significant for colorectal cancer, which is a heterogeneous complex of diseases developed in a sequential manner through a multistep carcinogenic process. As such, it is likely that tumors with similar characteristics might originate in the same manner and have a similar molecular behavior. Therefore, specific mapping of the molecular features can be potentially useful for both tumor classification and the development of appropriate therapeutic regimens. However, this can only be accomplished by developing high-affinity molecular probes with the ability to recognize specific markers associated with different tumors. Aptamers can most easily meet this challenge based on their target diversity, flexible manipulation and ease of development. METHODOLOGY AND RESULTS: Using a method known as cell-based Systematic Evolution of Ligands by Exponential enrichment (cell-SELEX and colorectal cancer cultured cell lines DLD-1 and HCT 116, we selected a panel of target-specific aptamers. Binding studies by flow cytometry and confocal microscopy showed that these aptamers have high affinity and selectivity. Our data further show that these aptamers neither recognize normal colon cells (cultured and fresh, nor do they recognize most other cancer cell lines tested. CONCLUSION/SIGNIFICANCE: The selected aptamers can identify specific biomarkers associated with colorectal cancers. We believe that these probes could be further developed for early disease detection, as well as prognostic markers, of colorectal cancers.

  19. Molecular mechanism of cisplatin resistance

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Cisplatin is widely used in the treatment of many tumors,particularly in ovarian cancer.GST-π,metallothionein(MT), multidrug resistance associated proteins(MRPs), nucleotide excision repair(NER), mismatch repair(MMR) and oncogenes contribute to drug resistance of cisplatin.

  20. Molecular-targeted therapy for elderly patients with advanced non-small cell lung cancer

    OpenAIRE

    Antonelli,Giovanna; Libra, Massimo; PANEBIANCO, VINCENZO; Russo,Alessia Erika; Vitale, Felice Vito; COLINA, PAOLO; D'Angelo,Alessandro; ROSSELLO, ROSALBA; Ferraù, Francesco

    2015-01-01

    Lung cancer is the most common cause of cancer-related mortality in men and women. Non-small cell lung cancer (NSCLC) represents close to 90% of all lung cancers. When diagnosed, >50% of patients are >65 years old. Through an improved understanding of the molecular mechanisms involved in lung oncogenesis, molecular-targeted approaches have become an essential element for the treatment of patients with NSCLC. As the toxicity profiles of the techniques are definitely more favorable compared wit...

  1. Insights into cancer severity from biomolecular interaction mechanisms

    Science.gov (United States)

    Raimondi, Francesco; Singh, Gurdeep; Betts, Matthew J.; Apic, Gordana; Vukotic, Ranka; Andreone, Pietro; Stein, Lincoln; Russell, Robert B.

    2016-01-01

    To attain a deeper understanding of diseases like cancer, it is critical to couple genetics with biomolecular mechanisms. High-throughput sequencing has identified thousands of somatic mutations across dozens of cancers, and there is a pressing need to identify the few that are pathologically relevant. Here we use protein structure and interaction data to interrogate nonsynonymous somatic cancer mutations, identifying a set of 213 molecular interfaces (protein-protein, -small molecule or –nucleic acid) most often perturbed in cancer, highlighting several potentially novel cancer genes. Over half of these interfaces involve protein-small-molecule interactions highlighting their overall importance in cancer. We found distinct differences in the predominance of perturbed interfaces between cancers and histological subtypes and presence or absence of certain interfaces appears to correlate with cancer severity. PMID:27698488

  2. Acoustic and photoacoustic molecular imaging of cancer.

    Science.gov (United States)

    Wilson, Katheryne E; Wang, Tzu Yin; Willmann, Jürgen K

    2013-11-01

    Ultrasound and combined optical and ultrasonic (photoacoustic) molecular imaging have shown great promise in the visualization and monitoring of cancer through imaging of vascular and extravascular molecular targets. Contrast-enhanced ultrasound with molecularly targeted microbubbles can detect early-stage cancer through the visualization of targets expressed on the angiogenic vasculature of tumors. Ultrasonic molecular imaging can be extended to the imaging of extravascular targets through use of nanoscale, phase-change droplets and photoacoustic imaging, which provides further molecular information on cancer given by the chemical composition of tissues and by targeted nanoparticles that can interact with extravascular tissues at the receptor level. A new generation of targeted contrast agents goes beyond merely increasing imaging signal at the site of target expression but shows activatable and differential contrast depending on their interactions with the tumor microenvironment. These innovations may further improve our ability to detect and characterize tumors. In this review, recent developments in acoustic and photoacoustic molecular imaging of cancer are discussed.

  3. Acoustic and Photoacoustic Molecular Imaging of Cancer

    Science.gov (United States)

    Wilson, Katheryne E.; Wang, Tzu Yin; Willmann, Jürgen K.

    2014-01-01

    Ultrasound and combined optical and ultrasonic (photoacoustic) molecular imaging have shown great promise in the visualization and monitoring of cancer through imaging of vascular and extravascular molecular targets. Contrast-enhanced ultrasound with molecularly targeted microbubbles can detect early-stage cancer through the visualization of targets expressed on the angiogenic vasculature of tumors. Ultrasonic molecular imaging can be extended to the imaging of extravascular targets through use of nanoscale, phase-change droplets and photoacoustic imaging, which provides further molecular information on cancer given by the chemical composition of tissues and by targeted nanoparticles that can interact with extravascular tissues at the receptor level. A new generation of targeted contrast agents goes beyond merely increasing imaging signal at the site of target expression but shows activatable and differential contrast depending on their interactions with the tumor microenvironment. These innovations may further improve our ability to detect and characterize tumors. In this review, recent developments in acoustic and photoacoustic molecular imaging of cancer are discussed. PMID:24187042

  4. Molecular mechanisms of NCAM function

    DEFF Research Database (Denmark)

    Hinsby, Anders M; Berezin, Vladimir; Bock, Elisabeth

    2004-01-01

    receptor that responds to both homophilic and heterophilic cues, as well as a mediator of cell-cell adhesion. This review describes NCAM function at the molecular level. We discuss recent models for extracellular ligand-interactions of NCAM, and the intracellular signaling cascade that follows to define...

  5. Quantum mechanics of molecular structures

    CERN Document Server

    Yamanouchi, Kaoru

    2012-01-01

    At a level accessible to advanced undergraduates, this textbook explains the fundamental role of quantum mechanics in determining the structure, dynamics, and other properties of molecules. Readers will come to understand the quantum-mechanical basis for harmonic oscillators, angular momenta and scattering processes. Exercises are provided to help readers deepen their grasp of the essential phenomena.

  6. Molecular deformation mechanisms in polyethylene

    CERN Document Server

    Coutry, S

    2001-01-01

    adjacent labelled stems is significantly larger when the DPE guest is a copolymer molecule. Our comparative studies on various types of polyethylene lead to the conclusion that their deformation behaviour under drawing has the same basis, with additional effects imputed to the presence of tie-molecules and branches. Three major points were identified in this thesis. The changes produced by drawing imply (1) the crystallisation of some of the amorphous polymer and the subsequent orientation of the newly formed crystals, (2) the re-orientation of the crystalline ribbons and (3) the beginning of crystallite break-up. However, additional effects were observed for the high molecular weight linear sample and the copolymer sample and were attributed, respectively, to the presence of tie-molecules and of branches. It was concluded that both the tie-molecules and the branches are restricting the molecular movement during deformation, and that the branches may be acting as 'anchors'. This work is concerned with details...

  7. Molecular and Clinical Markers of Pancreas Cancer

    OpenAIRE

    James L Buxbaum; Eloubeidi, Mohamad A

    2010-01-01

    Pancreas cancer has the worst prognosis of any solid tumor but is potentially treatable if it is diagnosed at an early stage. Thus there is critical interest in delineating clinical and molecular markers of incipient disease. The currently available biomarker, CA 19-9, has an inadequate sensitivity and specificity to achieve this objective. Diabetes mellitus, tobacco use, and chronic pancreatitis are associated with pancreas cancer. However, screening is currently only recommended in those wi...

  8. Bladder cancer: molecular determinants of personalized therapy.

    Science.gov (United States)

    Lopez-Beltran, Antonio; Santoni, Matteo; Massari, Francesco; Ciccarese, Chiara; Tortora, Giampaolo; Cheng, Liang; Moch, Holger; Scarpelli, Marina; Reymundo, Carlos; Montironi, Rodolfo

    2015-01-01

    Several molecular and genetic studies have provided new perspectives on the histologic classification of bladder tumors. Recent developments in the field of molecular mutational pathway analyses based on next generation sequencing technology together with classic data derived from the description of mutations in the FGFR3 (fibroblast growth factor receptor 3) gene, mutations on TP53 gene, and cDNA technology profiling data gives support to a differentiated taxonomy of bladder cancer. All these changes are behind the use of non-traditional approach to therapy of bladder cancer patients and are ready to change our daily practice of uro-oncology. The observed correlation of some molecular alterations with tumor behavior and the identification of their targets at cellular level might support the use of molecular changes together with morphological data to develop new clinical and biological strategies to manage patients with urothelial cancer. The current review provides comprehensive data to support personalized therapy for bladder cancer based on an integrated approach including pathologic and clinical features and molecular biology.

  9. Resveratrol and calcium signaling: molecular mechanisms and clinical relevance.

    Science.gov (United States)

    McCalley, Audrey E; Kaja, Simon; Payne, Andrew J; Koulen, Peter

    2014-06-05

    Resveratrol is a naturally occurring compound contributing to cellular defense mechanisms in plants. Its use as a nutritional component and/or supplement in a number of diseases, disorders, and syndromes such as chronic diseases of the central nervous system, cancer, inflammatory diseases, diabetes, and cardiovascular diseases has prompted great interest in the underlying molecular mechanisms of action. The present review focuses on resveratrol, specifically its isomer trans-resveratrol, and its effects on intracellular calcium signaling mechanisms. As resveratrol's mechanisms of action are likely pleiotropic, its effects and interactions with key signaling proteins controlling cellular calcium homeostasis are reviewed and discussed. The clinical relevance of resveratrol's actions on excitable cells, transformed or cancer cells, immune cells and retinal pigment epithelial cells are contrasted with a review of the molecular mechanisms affecting calcium signaling proteins on the plasma membrane, cytoplasm, endoplasmic reticulum, and mitochondria. The present review emphasizes the correlation between molecular mechanisms of action that have recently been identified for resveratrol and their clinical implications.

  10. Molecular and Clinical Markers of Pancreas Cancer

    Directory of Open Access Journals (Sweden)

    James L Buxbaum

    2010-11-01

    Full Text Available Pancreas cancer has the worst prognosis of any solid tumor but is potentially treatable if it is diagnosed at an early stage. Thus there is critical interest in delineating clinical and molecular markers of incipient disease. The currently available biomarker, CA 19-9, has an inadequate sensitivity and specificity to achieve this objective. Diabetes mellitus, tobacco use, and chronic pancreatitis are associated with pancreas cancer. However, screening is currently only recommended in those with hereditary pancreatitis and genetic syndromes which predispose to cancer. Ongoing work to identify early markers of pancreas cancer consists of high throughput discovery methods including gene arrays and proteomics as well as hypothesis driven methods. While several promising candidates have been identified none has yet been convincingly proven to be better than CA 19-9. New methods including endoscopic ultrasound are improving detection of pancreas cancer and are being used to acquire tissue for biomarker discovery.

  11. Molecular markers for prostate cancer.

    NARCIS (Netherlands)

    Reynolds, M.A.; Kastury, K.; Groskopf, J.; Schalken, J.A.; Rittenhouse, H.G.

    2007-01-01

    Serum PSA testing has been used for over 20 years as an aid in the diagnosis and management of prostate cancer. Although highly sensitive, it suffers from a lack of specificity, showing elevated serum levels in a variety of other conditions including prostatitis, benign prostate hyperplasia, and non

  12. Molecular mechanism of insulin resistance

    Indian Academy of Sciences (India)

    Samir Bhattacharya; Debleena Dey; Sib Sankar Roy

    2007-03-01

    Free fatty acids are known to play a key role in promoting loss of insulin sensitivity, thereby causing insulin resistance and type 2 diabetes. However, the underlying mechanism involved is still unclear. In searching for the cause of the mechanism, it has been found that palmitate inhibits insulin receptor (IR) gene expression, leading to a reduced amount of IR protein in insulin target cells. PDK1-independent phosphorylation of PKCε causes this reduction in insulin receptor gene expression. One of the pathways through which fatty acid can induce insulin resistance in insulin target cells is suggested by these studies. We provide an overview of this important area, emphasizing the current status.

  13. Molecular mechanisms of antibiotic resistance.

    Science.gov (United States)

    Blair, Jessica M A; Webber, Mark A; Baylay, Alison J; Ogbolu, David O; Piddock, Laura J V

    2015-01-01

    Antibiotic-resistant bacteria that are difficult or impossible to treat are becoming increasingly common and are causing a global health crisis. Antibiotic resistance is encoded by several genes, many of which can transfer between bacteria. New resistance mechanisms are constantly being described, and new genes and vectors of transmission are identified on a regular basis. This article reviews recent advances in our understanding of the mechanisms by which bacteria are either intrinsically resistant or acquire resistance to antibiotics, including the prevention of access to drug targets, changes in the structure and protection of antibiotic targets and the direct modification or inactivation of antibiotics.

  14. Molecular mechanism of traditional chinese medicine inhibited colon cancer proliferation and promoted apoptosis%中药抑制结肠癌细胞增殖、促进凋亡的分子机制

    Institute of Scientific and Technical Information of China (English)

    印滇; 姚登福

    2012-01-01

    结肠癌(colon cancer)已为常见的恶性肿瘤之一,有转移者5年生存率仅有8%.我国传统的中医在治疗结肠癌中,彰显了增效减毒的优势,具有抗肿瘤作用.近年来,中药对结肠癌细胞系体外培养生长的抑制作用、增强机体免疫功能以及对细胞周期、细胞凋亡的影响等进行了有益的探索.本文就中药抑制结肠癌细胞增殖、促进凋亡的分子机制与研究进展作一综述.%Colon cancer ( CC) is one of the common cancers worldwide, and the 5-year survival rate of the CC patients with metastasis is only 8% . Chinese traditional medicine shows the synergistic and attenuated advantages than western medicine, also has some anti-tumor effect. This article reviews the molecular mechanisms and research progress of traditional Chinese medicine treatment of colon cancer.

  15. Molecular mechanisms and treatment options for muscle wasting eiseases

    OpenAIRE

    Rüegg, Markus A; Glass, David J.

    2010-01-01

    Loss of muscle mass can be the consequence of pathological changes, as observed in muscular dystrophies; or it can be secondary to cachexia-inducing diseases that cause muscle atrophy, such as cancer, heart disease, or chronic obstructive pulmonary disease; or it can be a consequence of aging or simple disuse. Although muscular dystrophies are rare, muscle loss affects millions of people worldwide.Wediscuss the molecular mechanisms involved in muscular dystrophy and in muscle atrophy and pres...

  16. Cancer cachexia, mechanism and treatment

    Institute of Scientific and Technical Information of China (English)

    Tomoyoshi Aoyagi; Krista P Terracina; Ali Raza; Hisahiro Matsubara; Kazuaki Takabe

    2015-01-01

    It is estimated that half of all patients with cancereventually develop a syndrome of cachexia, with anorexiaand a progressive loss of adipose tissue and skeletalmuscle mass. Cancer cachexia is characterized by systemicinflammation, negative protein and energy balance, andan involuntary loss of lean body mass. It is an insidioussyndrome that not only has a dramatic impact on patientquality of life, but also is associated with poor responsesto chemotherapy and decreased survival. Cachexia isstill largely an underestimated and untreated condition,despite the fact that multiple mechanisms are reported tobe involved in its development, with a number of cytokinespostulated to play a role in the etiology of the persistentcatabolic state. Existing therapies for cachexia, includingorexigenic appetite stimulants, focus on palliation ofsymptoms and reduction of the distress of patients andfamilies rather than prolongation of life. Recent therapiesfor the cachectic syndrome involve a multidisciplinaryapproach. Combination therapy with diet modificationand/or exercise has been added to novel pharmaceuticalagents, such as Megestrol acetate, medroxyprogesterone,ghrelin, omega-3-fatty acid among others. These agentsare reported to have improved survival rates as well asquality of life. In this review, we will discuss the emergingunderstanding of the mechanisms of cancer cachexia,the current treatment options including multidisciplinarycombination therapies, as well an update on new andongoing clinical trials.

  17. Ovarian cancer: a molecularly insidious disease.

    Science.gov (United States)

    Mezzanzanica, Delia

    2015-01-01

    In this issue of the Chinese Journal of Cancer, European, American, and Chinese experts review the current management and future perspectives of epithelial ovarian cancer (EOC), the leading cause of gynecological cancer deaths. Although major advances have been made in understanding the cellular and molecular biology of this highly heterogeneous malignancy, the survival rate of women with EOC has changed little since the introduction of platinum-based treatment as a front-line therapy. The papers describe the progress in deciphering the molecular complexity of this disease and the newly available molecular-driven therapies, which have been applied by shifting trial designs toward restricting eligibility to specific subgroups of patients rather than testing agents in unselected populations. These new trial designs provide potential opportunities for improved efficacy in targeted populations. Given the molecular complexity of this disease, patient survival may be increased by searching for new molecular prognostic/predictive signatures as well as by translating the recent insight of microRNA involvement in EOC progression into new, targeted therapies. Particular attention has been given to the issue of fertility sparing for women affected by curable diseases.

  18. Molecular Mechanisms of Appetite Regulation

    Directory of Open Access Journals (Sweden)

    Ji Hee Yu

    2012-12-01

    Full Text Available The prevalence of obesity has been rapidly increasing worldwide over the last several decades and has become a major health problem in developed countries. The brain, especially the hypothalamus, plays a key role in the control of food intake by sensing metabolic signals from peripheral organs and modulating feeding behaviors. To accomplish these important roles, the hypothalamus communicates with other brain areas such as the brainstem and reward-related limbic pathways. The adipocyte-derived hormone leptin and pancreatic β-cell-derived insulin inform adiposity to the hypothalamus. Gut hormones such as cholecystokinin, peptide YY, pancreatic polypeptide, glucagon-like peptide 1, and oxyntomodulin transfer satiety signals to the brain and ghrelin relays hunger signals. The endocannabinoid system and nutrients are also involved in the physiological regulation of food intake. In this article, we briefly review physiological mechanisms of appetite regulation.

  19. Cellular and molecular effects of yeast probiotics on cancer.

    Science.gov (United States)

    Saber, Amir; Alipour, Beitollah; Faghfoori, Zeinab; Yari Khosroushahi, Ahmad

    2017-02-01

    The cancer is one of the main causes of human deaths worldwide. The exact mechanisms of initiation and progression of malignancies are not clear yet, but there is a common agreement about the role of colonic microbiota in the etiology of different cancers. Probiotics have been examined for their anti-cancer effects, and different mechanisms have been suggested about their antitumor functions. Nonpathogenic yeasts, as members of probiotics family, can be effective on gut microbiota dysbiosis. Generally safe yeasts have shown so many beneficial effects on human health. Probiotic yeasts influence physiology, metabolism, and immune homeostasis in the colon and contribute to cancer treatment due to possessing anti-inflammatory, anti-proliferative and anti-cancer properties. This study reviews some of the health-beneficial effects of probiotic yeasts and their biological substances like folic acid and β-glucan on cancer and focuses on the possible cellular and molecular mechanisms of probiotic yeasts such as influencing pathogenic bacteria, inactivation of carcinogenic compounds, especially those derived from food, improvement of intestinal barrier function, modulation of immune responses, antitoxic function, apoptosis, and anti-proliferative effects.

  20. Molecular pathogenesis ofsporadic colorectal cancers

    Institute of Scientific and Technical Information of China (English)

    HidetsuguYamagishi; HajimeKuroda; YasuoImai; HideyukiHiraishi

    2016-01-01

    Colorectal cancer (CRC) results from the progressive accumulation of genetic and epigenetic alterations that lead to the transformation of normal colonic mucosa to adenocarcinoma. Approximately 75% of CRCs are sporadic and occur in people without genetic predisposition or family history of CRC. During the past two decades, sporadic CRCs were classiifed into three major groups according to frequently altered/mutated genes. These genes have been identiifed by linkage analyses of cancer-prone families and by individual mutation analyses of candidate genes selected on the basis of functional data. In the ifrst half of this review, we describe the genetic pathways of sporadic CRCs and their clinicopathologic features. Recently, large-scale genome analyses have detected many infrequently mutated genes as well as a small number of frequently mutated genes. These infrequently mutated genes are likely described in a lim-ited number of pathways. Gene-oriented models of CRC progression are being replaced by pathway-oriented models. In the second half of this review, we summarize the present knowledge of this research ifeld and discuss its prospects.

  1. Quantum Mechanics/Molecular Mechanics Modeling of Drug Metabolism

    DEFF Research Database (Denmark)

    Lonsdale, Richard; Fort, Rachel M; Rydberg, Patrik;

    2016-01-01

    The mechanism of cytochrome P450(CYP)-catalyzed hydroxylation of primary amines is currently unclear and is relevant to drug metabolism; previous small model calculations have suggested two possible mechanisms: direct N-oxidation and H-abstraction/rebound. We have modeled the N-hydroxylation of (R......)-mexiletine in CYP1A2 with hybrid quantum mechanics/molecular mechanics (QM/MM) methods, providing a more detailed and realistic model. Multiple reaction barriers have been calculated at the QM(B3LYP-D)/MM(CHARMM27) level for the direct N-oxidation and H-abstraction/rebound mechanisms. Our calculated barriers...... indicate that the direct N-oxidation mechanism is preferred and proceeds via the doublet spin state of Compound I. Molecular dynamics simulations indicate that the presence of an ordered water molecule in the active site assists in the binding of mexiletine in the active site...

  2. Molecular mechanisms of DNA photodamage

    Energy Technology Data Exchange (ETDEWEB)

    Starrs, S.M

    2000-05-01

    Photodamage in DNA, caused by ultraviolet (UV) light, can occur by direct excitation of the nucleobases or indirectly via the action of photosensitisers. Such, DNA photodamage can be potentially mutagenic or lethal. Among the methods available for detecting UV-induced DNA damage, gel sequencing protocols, utilising synthetic oligodeoxyribonucleotides as targets for UV radiation, allow photolesions to be mapped at nucleotide resolution. This approach has been applied to investigate both DNA damage mechanisms. Following a general overview of DNA photoreactivity, and a description of the main experimental procedures, Chapter 3 identifies the origin of an anomalous mobility shift observed in purine chemical sequence ladders that can confuse the interpretation of DNA cleavage results; measures to abolish this shift are also described. Chapters 4 and 5 examine the alkali-labile DNA damage photosensitised by representative nonsteroidal antiinflammatory drugs (NSAIDs) and the fluoroquinolone antibiotics. Suprofen was the most photoactive NSAID studied, producing different patterns of guanine-specific damage in single-stranded and duplex DNA. Uniform modification of guanine bases, typifying attack by singlet oxygen, was observed in single-stranded oligodeoxyribonucleotides. In duplex molecules, modification was limited to the 5'-G of GG doublets, which is indicative of an electron transfer. The effect of quenchers and photoproduct analysis substantiated these findings. The quinolone, nalidixic acid, behaves similarly. The random base cleavage photosensitised by the fluoroquinolones, has been attributed to free radicals produced during their photodecomposition. Chapter 6 addresses the photoreactivity of purines within unusual DNA structures formed by the repeat sequences (GGA){sub n} and (GA){sub n}, and a minihairpin. There was no definitive evidence for enhanced purine reactivity caused by direct excitation. Finally, Chapter 7 investigates the mutagenic potential of a

  3. Cocoa phytochemicals: recent advances in molecular mechanisms on health.

    Science.gov (United States)

    Kim, Jiyoung; Kim, Jaekyoon; Shim, Jaesung; Lee, Chang Yong; Lee, Ki Won; Lee, Hyong Joo

    2014-01-01

    Recent reports on cocoa are appealing in that a food commonly consumed for pure pleasure might also bring tangible benefits for human health. Cocoa consumption is correlated with reduced health risks of cardiovascular diseases, hypertension, atherosclerosis, and cancer, and the health-promoting effects of cocoa are mediated by cocoa-driven phytochemicals. Cocoa is rich in procyanidins, theobromine, (-)-epicatechin, catechins, and caffeine. Among the phytochemicals present in consumed cocoa, theobromine is most available in human plasma, followed by caffeine, (-)-epicatechin, catechin, and procyanidins. It has been reported that cocoa phytochemicals specifically modulate or interact with specific molecular targets linked to the pathogenesis of chronic human diseases, including cardiovascular diseases, cancer, neurodegenerative diseases, obesity, diabetes, and skin aging. This review summarizes comprehensive recent findings on the beneficial actions of cocoa-driven phytochemicals in molecular mechanisms of human health.

  4. Molecular diagnosis of prostate cancer: Topical issues

    Directory of Open Access Journals (Sweden)

    E. N. Knyazev

    2014-12-01

    Full Text Available Prostate cancer (PC is the second most common cancer and the fifth highest malignancy mortality rate in men worldwide. Although PC is detectable in 15-20% of men during life, its death risk is only about 3%. This means that not all PC cases require the same management tactics. The given review analyzes the current investigations searching for molecular biological markers to predict the course of PC and to choose its treatment policy, including that in the development of resistance to androgen-deprivation therapy.

  5. Loss of post-transcriptional regulation of DNMT3b by microRNAs: a possible molecular mechanism for the hypermethylation defect observed in a subset of breast cancer cell lines.

    Science.gov (United States)

    Sandhu, Rupninder; Rivenbark, Ashley G; Coleman, William B

    2012-08-01

    A hypermethylation defect associated with DNMT hyperactivity and DNMT3b overexpression characterizes a subset of breast cancers and breast cancer cell lines. We analyzed breast cancer cell lines for differential expression of regulatory miRs to determine if loss of miR-mediated post-transcriptional regulation of DNMT3b represents the molecular mechanism that governs the overexpression of DNMT3b that drives the hypermethylation defect in breast cancer. MicroRNAs (miRs) that regulate (miR-29a, miR-29b, miR-29c, miR-148a, miR-148b) or are predicted (miR-26a, miR-26b, miR-203, miR-222) to regulate DNMT3b were examined among 10 hypermethylator and 6 non-hypermethylator breast cancer cell lines. Hypermethylator cell lines express diminished levels of miR-29c, miR-148a, miR-148b, miR-26a, miR-26b, and miR-203 compared to non-hypermethylator cell lines. miR expression patterns correlate inversely with methylation-sensitive gene expression (r=-0.66, p=0.0056) and directly with the methylation status of these genes (r=0.72, p=0.002). To determine the mechanistic role of specific miRs in the dysregulation of DNMT3b among breast cancer cell lines, miR levels were modulated by transfection of pre-miR precursors for miR-148b, miR-26b, and miR-29c into hypermethylator cell lines (Hs578T, HCC1937, SUM185) and transfection of antagomirs directed against miR-148b, miR-26b, and miR-29c into non-hypermethylator cell lines (BT20, MDA-MB-415, MDA-MB-468). Antagomir-mediated knock-down of miR-148b, miR-29c, and miR-26b significantly increased DNMT3b mRNA in non-hypermethylator cell lines, and re-expression of miR-148b, miR-29c, and miR-26b following transfection of pre-miR precursors significantly reduced DNMT3b mRNA in hypermethylator cell lines. These findings strongly suggest that: i) post-transcriptional regulation of DNMT3b is combinatorial, ii) diminished expression of regulatory miRs contributes to DNMT3b overexpression, iii) re-expression of regulatory miRs reduces DNMT3b m

  6. 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

  7. Cellular and molecular aspects of gastric cancer

    Institute of Scientific and Technical Information of China (English)

    Malcolm G Smith; Georgina L Hold; Eiichi Tahara; Emad M El-Omar

    2006-01-01

    Gastric cancer remains a global killer with a shifting burden from the developed to the developing world.The cancer develops along a multistage process that is defined by distinct histological and pathophysiological phases. Several genetic and epigenetic alterations mediate the transition from one stage to another and these include mutations in oncogenes, tumour suppressor genes and cell cycle and mismatch repair genes. The most significant advance in the fight against gastric caner came with the recognition of the role of Helicobacter pylori (H pylori) as the most important acquired aetiological agent for this cancer. Recent work has focussed on elucidating the complex host/microbial interactions that underlie the neoplastic process. There is now considerable insight into the pathogenesis of this cancer and the prospect of preventing and eradicating the disease has become a reality. Perhaps more importantly, the study of H pylori-induced gastric carcinogenesis offers a paradigm for understanding more complex human cancers. In this review, we examine the molecular and cellular events that underlie H pyloriinduced gastric cancer.

  8. Pathogenesis and Molecular Mechanisms of Zika Virus.

    Science.gov (United States)

    Nayak, Shriddha; Lei, Jun; Pekosz, Andrew; Klein, Sabra; Burd, Irina

    2016-09-01

    Zika virus (ZIKV) is one of the most important emerging viruses of 2016. A developing outbreak in the Americas has demonstrated an association between the virus and serious clinical manifestations, such as Guillain-Barré syndrome in adults and congenital malformations in infants born to infected mothers. Pathogenesis and mechanisms of neurologic or immune disease by ZIKV have not been clearly delineated. However, several pathways have been described to explain viral involvement in brain and immune system as well as other organ systems such as eye, skin, and male and female reproductive tracts. ZIKV activates toll-like receptor 3 and several pathways have been described to explain the mechanisms at a molecular level. The mechanism of microcephaly has been more difficult to demonstrate experimentally, likely due to the multifactorial and complex nature of the phenotype. This article provides an overview of existing literature on ZIKV pathogenicity and possible molecular mechanisms of disease as outlined to date.

  9. Modelling the molecular mechanisms of aging.

    Science.gov (United States)

    Mc Auley, Mark T; Guimera, Alvaro Martinez; Hodgson, David; Mcdonald, Neil; Mooney, Kathleen M; Morgan, Amy E; Proctor, Carole J

    2017-02-28

    The aging process is driven at the cellular level by random molecular damage that slowly accumulates with age. Although cells possess mechanisms to repair or remove damage, they are not 100% efficient and their efficiency declines with age. There are many molecular mechanisms involved and exogenous factors such as stress also contribute to the aging process. The complexity of the aging process has stimulated the use of computational modelling in order to increase our understanding of the system, test hypotheses and make testable predictions. As many different mechanisms are involved, a wide range of models have been developed. This paper gives an overview of the types of models that have been developed, the range of tools used, modelling standards and discusses many specific examples of models that have been grouped according to the main mechanisms that they address. We conclude by discussing the opportunities and challenges for future modelling in this field.

  10. Molecular biology of breast cancer stem cells: potential clinical applications.

    Science.gov (United States)

    Nguyen, Nam P; Almeida, Fabio S; Chi, Alex; Nguyen, Ly M; Cohen, Deirdre; Karlsson, Ulf; Vinh-Hung, Vincent

    2010-10-01

    Breast cancer stem cells (CSC) have been postulated recently as responsible for failure of breast cancer treatment. The purpose of this study is to review breast CSCs molecular biology with respect to their mechanism of resistance to conventional therapy, and to develop treatment strategies that may improve survival of breast cancer patients. A literature search has identified in vitro and in vivo studies of breast CSCs. Breast CSCs overexpress breast cancer resistance protein (BCRP) which allows cancer cells to transport actively chemotherapy agents out of the cells. Radioresistance is modulated through activation of Wnt signaling pathway and overexpression of genes coding for glutathione. Lapatinib can selectively target HER-2 positive breast CSCs and improves disease-free survival in these patients. Metformin may target basal type breast CSCs. Parthenolide and oncolytic viruses are promising targeting agents for breast CSCs. Future clinical trials for breast cancer should include anti-cancer stem cells targeting agents in addition to conventional chemotherapy. Hypofractionation radiotherapy may be indicated for residual disease post chemotherapy.

  11. Pain and nociception: mechanisms of cancer-induced bone pain.

    Science.gov (United States)

    Falk, Sarah; Dickenson, Anthony H

    2014-06-01

    Cancer pain, especially pain caused by metastasis to bone, is a severe type of pain, and unless the cause and consequences can be resolved, the pain will become chronic. As detection and survival among patients with cancer have improved, pain has become an increasing challenge, because traditional therapies are often only partially effective. Until recently, knowledge of cancer pain mechanisms was poor compared with understanding of neuropathic and inflammatory pain states. We now view cancer-induced bone pain as a complex pain state involving components of both inflammatory and neuropathic pain but also exhibiting elements that seem unique to cancer pain. In addition, the pain state is often unpredictable, and the intensity of the pain is highly variable, making it difficult to manage. The establishment of translational animal models has started to reveal some of the molecular components involved in cancer pain. We present the essential pharmacologic and neurobiologic mechanisms involved in the generation and continuance of cancer-induced bone pain and discuss these in the context of understanding and treating patients. We discuss changes in peripheral signaling in the area of tumor growth, examine spinal cord mechanisms of sensitization, and finally address central processing. Our aim is to provide a mechanistic background for the sensory characteristics of cancer-induced bone pain as a basis for better understanding and treating this condition.

  12. Molecular mechanisms of drug-induced thrombocytopenia

    NARCIS (Netherlands)

    Burgess, Janette K.

    2001-01-01

    A wide range of drugs can induce thrombocytopenia. Molecular mechanisms for the formation of specific epitopes for all the drug-dependent antibodies appear to be very similar. A restricted set of glycoproteins on the platelet surface interacts with the drugs to form neoepitopes, to which the drug-de

  13. Mechanical transduction mechanisms of RecA-like molecular motors.

    Science.gov (United States)

    Liao, Jung-Chi

    2011-12-01

    A majority of ATP-dependent molecular motors are RecA-like proteins, performing diverse functions in biology. These RecA-like molecular motors consist of a highly conserved core containing the ATP-binding site. Here I examined how ATP binding within this core is coupled to the conformational changes of different RecA-like molecular motors. Conserved hydrogen bond networks and conformational changes revealed two major mechanical transduction mechanisms: (1) intra-domain conformational changes and (2) inter-domain conformational changes. The intra-domain mechanism has a significant hydrogen bond rearrangement within the domain containing the P-loop, causing relative motion between two parts of the protein. The inter-domain mechanism exhibits little conformational change in the P-loop domain. Instead, the major conformational change is observed between the P-loop domain and an adjacent domain or subunit containing the arginine finger. These differences in the mechanical transduction mechanisms may link to the underlying energy surface governing a Brownian ratchet or a power stroke.

  14. [Cellular and molecular mechanisms of memory].

    Science.gov (United States)

    Laroche, Serge

    2010-01-01

    A defining characteristic of the brain is its remarkable capacity to undergo activity-dependent functional and morphological remodelling via mechanisms of plasticity that form the basis of our capacity to encode and retain memories. Today, it is generally accepted that one key neurobiological mechanism underlying the formation of memories reside in activity-driven modifications of synaptic strength and structural remodelling of neural networks activated during learning. The discovery and detailed report of the phenomenon generally known as long-term potentiation, a long-lasting activity-dependent form of synaptic strengthening, opened a new chapter in the study of the neurobiological substrate of memory in the vertebrate brain, and this form of synaptic plasticity has now become the dominant model in the search for the cellular bases of learning and memory. To date, the key events in the cellular and molecular mechanisms underlying synaptic plasticity and memory formation are starting to be identified. They require the activation of specific receptors and of several molecular cascades to convert extracellular signals into persistent functional changes in neuronal connectivity. Accumulating evidence suggests that the rapid activation of neuronal gene programs is a key mechanism underlying the enduring modification of neural networks required for the laying down of memory. The recent developments in the search for the cellular and molecular mechanisms of memory storage are reviewed.

  15. Combination of metformin with chemotherapeutic drugs via different molecular mechanisms.

    Science.gov (United States)

    Peng, Mei; Darko, Kwame Oteng; Tao, Ting; Huang, Yanjun; Su, Qiongli; He, Caimei; Yin, Tao; Liu, Zhaoqian; Yang, Xiaoping

    2017-03-01

    Metformin, a widely prescribed drug for treating type II diabetes, is one of the most extensively recognized metabolic modulators which has shown an important anti-cancer property. However, fairly amount of clinical trials on its single administration have not demonstrated a convincing efficiency yet. Thus, recent studies tend to combine metformin with clinical commonly used chemotherapeutic drugs to decrease their toxicity and attenuate their tumor resistance. These strategies have displayed promising clinical benefits. Interestingly, metformin experiences a diversity of molecular mechanisms when it combines different chemotherapeutic drugs. For example, AMPK/mTOR signaling pathway activation plays a major role when it combines with hormone modulating drugs. In contrast, suppression of HIF-1, p-gp and MRP1 protein expression is its main mechanism when metformin combines with anti-metabolites. Furthermore, when combining of metformin with antibiotics, inhibition of oxidative stress and inflammatory signaling pathway becomes a novel pharmaceutical mechanism for its cardio-protective effect. Induction of apoptotic mitochondria and nucleus could be the major player for the synergistic effect of its combination with cisplatin. In contrast, down-regulation of lipoprotein or cholesterol synthesis might be the undefined molecular base when metformin combines with taxane. Thus, deep exploration of molecular mechanisms of metformin with these different drugs is critical to understand its synergistic effect and help for personalized administration. In this mini-review, detailed molecular mechanisms of these combinations are discussed and summarized. This work will promote better understanding of molecular mechanisms of metformin and provide precise targets to identify specific patient groups to achieve satisfactory treatment efficacy.

  16. Teratogenic effects of thalidomide: molecular mechanisms.

    Science.gov (United States)

    Ito, Takumi; Ando, Hideki; Handa, Hiroshi

    2011-05-01

    Fifty years ago, prescription of the sedative thalidomide caused a worldwide epidemic of multiple birth defects. The drug is now used in the treatment of leprosy and multiple myeloma. However, its use is limited due to its potent teratogenic activity. The mechanism by which thalidomide causes limb malformations and other developmental defects is a long-standing question. Multiple hypotheses exist to explain the molecular mechanism of thalidomide action. Among them, theories involving oxidative stress and anti-angiogenesis have been widely supported. Nevertheless, until recently, the direct target of thalidomide remained elusive. We identified a thalidomide-binding protein, cereblon (CRBN), as a primary target for thalidomide teratogenicity. Our data suggest that thalidomide initiates its teratogenic effects by binding to CRBN and inhibiting its ubiquitin ligase activity. In this review, we summarize the biology of thalidomide, focusing on the molecular mechanisms of its teratogenic effects. In addition, we discuss the questions still to be addressed.

  17. Trastuzumab: updated mechanisms of action and resistance in breast cancer

    Directory of Open Access Journals (Sweden)

    Francois X. Claret

    2012-06-01

    Full Text Available HER2-postitive breast cancer has the second-poorest prognosis among breast cancer subtypes. One of the most effective targeted therapies for patients with HER2-positive breast cancer is trastuzumab-based. However, primary or acquired resistance to trastuzumab has been a major obstacle in the clinical management of this disease. Therefore, to better control HER2-postitive breast cancer, it is necessary to gain a deeper understanding of trastuzumab’s actions and the pathways that cancer cells use to dodge its effects. In this review, we attempt to give an overview of the widely accepted and currently proposed molecular mechanisms for these actions and highlight recent advances in our understanding of HER2 targeted therapies.

  18. Sampling Molecular Conformers in Solution with Quantum Mechanical Accuracy at a Nearly Molecular-Mechanics Cost.

    Science.gov (United States)

    Rosa, Marta; Micciarelli, Marco; Laio, Alessandro; Baroni, Stefano

    2016-09-13

    We introduce a method to evaluate the relative populations of different conformers of molecular species in solution, aiming at quantum mechanical accuracy, while keeping the computational cost at a nearly molecular-mechanics level. This goal is achieved by combining long classical molecular-dynamics simulations to sample the free-energy landscape of the system, advanced clustering techniques to identify the most relevant conformers, and thermodynamic perturbation theory to correct the resulting populations, using quantum-mechanical energies from density functional theory. A quantitative criterion for assessing the accuracy thus achieved is proposed. The resulting methodology is demonstrated in the specific case of cyanin (cyanidin-3-glucoside) in water solution.

  19. Molecular mechanisms for tumour resistance to chemotherapy.

    Science.gov (United States)

    Pan, Shu-Ting; Li, Zhi-Ling; He, Zhi-Xu; Qiu, Jia-Xuan; Zhou, Shu-Feng

    2016-08-01

    Chemotherapy is one of the prevailing methods used to treat malignant tumours, but the outcome and prognosis of tumour patients are not optimistic. Cancer cells gradually generate resistance to almost all chemotherapeutic drugs via a variety of distinct mechanisms and pathways. Chemotherapeutic resistance, either intrinsic or acquired, is caused and sustained by reduced drug accumulation and increased drug export, alterations in drug targets and signalling transduction molecules, increased repair of drug-induced DNA damage, and evasion of apoptosis. In order to better understand the mechanisms of chemoresistance, this review highlights our current knowledge of the role of altered drug metabolism and transport and deregulation of apoptosis and autophagy in the development of tumour chemoresistance. Reduced intracellular activation of prodrugs (e.g. thiotepa and tegafur) or enhanced drug inactivation by Phase I and II enzymes contributes to the development of chemoresistance. Both primary and acquired resistance can be caused by alterations in the transport of anticancer drugs which is mediated by a variety of drug transporters such as P-glycoprotein (P-gp), multidrug resistance associated proteins, and breast cancer resistance protein. Presently there is a line of evidence indicating that deregulation of programmed cell death including apoptosis and autophagy is also an important mechanism for tumour resistance to anticancer drugs. Reversal of chemoresistance is likely via pharmacological and biological approaches. Further studies are warranted to grasp the full picture of how each type of cancer cells develop resistance to anticancer drugs and to identify novel strategies to overcome it.

  20. Cellular and molecular mechanisms underlie the anti-tumor activities exerted by Walterinnesia aegyptia venom combined with silica nanoparticles against multiple myeloma cancer cell types.

    Directory of Open Access Journals (Sweden)

    Gamal Badr

    +NP and the underlying mechanisms against myeloma cancer cells.

  1. Molecular Mechanisms of Neuroplasticity: An Expanding Universe.

    Science.gov (United States)

    Gulyaeva, N V

    2017-03-01

    Biochemical processes in synapses and other neuronal compartments underlie neuroplasticity (functional and structural alterations in the brain enabling adaptation to the environment, learning, memory, as well as rehabilitation after brain injury). This basic molecular level of brain plasticity covers numerous specific proteins (enzymes, receptors, structural proteins, etc.) participating in many coordinated and interacting signal and metabolic processes, their modulation forming a molecular basis for brain plasticity. The articles in this issue are focused on different "hot points" in the research area of biochemical mechanisms supporting neuroplasticity.

  2. Molecular mechanism of Endosulfan action in mammals

    Indian Academy of Sciences (India)

    ROBIN SEBASTIAN; SATHEES C RAGHAVAN

    2017-03-01

    Endosulfan is a broad-spectrum organochlorine pesticide, speculated to be detrimental to human health in areas ofactive exposure. However, the molecular insights to its mechanism of action remain poorly understood. In two recentstudies, our group investigated the physiological and molecular aspects of endosulfan action using in vitro, ex vivo andin vivo analyses. The results showed that apart from reducing fertility levels in male animals, Endosulfan inducedDNA damage that triggers compromised DNA damage response leading to undesirable processing of broken DNAends. In this review, pesticide use especially of Endosulfan in the Indian scenario is summarized and the importance ofour findings, especially the rationalized use of pesticides in the future, is emphasized.

  3. Molecular aspects of prostate cancer: implications for future directions

    Directory of Open Access Journals (Sweden)

    Etel R. P. Gimba

    2003-10-01

    Full Text Available Many studies have been developed trying to understand the complex molecular mechanisms involved in oncogenesis and progression of prostate cancer (PCa. Current biotechnological methodologies, especially genomic studies, are adding important aspects to this area. The construction of extensive DNA sequence data and gene expression profiles have been intensively explored to search for candidate biomarkers to evaluate PCa. The use of DNA micro-array robotic systems constitutes a powerful approach to simultaneously monitor the expression of a great number of genes. The resulting gene expressing profiles can be used to specifically describe tumor staging and response to cancer therapies. Also, it is possible to follow PCa pathological properties and to identify genes that anticipate the behavior of clinical disease. The molecular pathogenesis of PCa involves many contributing factors, such as alterations in signal transduction pathways, angiogenesis, adhesion molecules expression and cell cycle control. Also, molecular studies are making clear that many genes, scattered through several different chromosomal regions probably cause predisposition to PCa. The discovery of new molecular markers for PCa is another relevant advance resulting from molecular biology studies of prostate tumors. Interesting tissue and serum markers have been reported, resulting in many cases in useful novelties to diagnostic and prognostic approaches to follow-up PCa. Finally, gene therapy comes as an important approach for therapeutic intervention in PCa. Clinical trials for PCa have been demonstrating that gene therapy is relatively safe and well tolerated, although some improvements are yet to be developed.

  4. Emerging Anticancer Potentials of Goniothalamin and Its Molecular Mechanisms

    Directory of Open Access Journals (Sweden)

    Mohamed Ali Seyed

    2014-01-01

    Full Text Available The treatment of most cancers is still inadequate, despite tremendous steady progress in drug discovery and effective prevention. Nature is an attractive source of new therapeutics. Several medicinal plants and their biomarkers have been widely used for the treatment of cancer with less known scientific basis of their functioning. Although a wide array of plant derived active metabolites play a role in the prevention and treatment of cancer, more extensive scientific evaluation of their mechanisms is still required. Styryl-lactones are a group of secondary metabolites ubiquitous in the genus Goniothalamus that have demonstrated to possess antiproliferative activity against cancer cells. A large body of evidence suggests that this activity is associated with the induction of apoptosis in target cells. In an effort to promote further research on the genus Goniothalamus, this review offers a broad analysis of the current knowledge on Goniothalamin (GTN or 5, 6, dihydro-6-styryl-2-pyronone (C13H12O2, a natural occurring styryl-lactone. Therefore, it includes (i the source of GTN and other metabolites; (ii isolation, purification, and (iii the molecular mechanisms of actions of GTN, especially the anticancer properties, and summarizes the role of GTN which is crucial for drug design, development, and application in future for well-being of humans.

  5. Molecular mechanism of cisplatin resistance in ovarian cancer%卵巢癌顺铂耐药分子生物学研究进展

    Institute of Scientific and Technical Information of China (English)

    韩雪川; 樊杨

    2012-01-01

    化疗耐药是有效治疗卵巢癌的重大障碍.卵巢癌耐药是多因素、多因子共同作用的结果,耐药相关基因的深入研究为从根本上逆转肿瘤耐药提供了新的思路.%Chemotherapy resistance is a great obstacle for effective treatment of ovarian cancer.Drug resistance of ovarian cancer is the results of combined action of multi- factors.Further study of drug resistancerelated genes can provide new ideas for reversing drug resistance fundamentally.

  6. SU-E-I-39: Molecular Image Guided Cancer Stem Cells Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Abdollahi, H

    2014-06-01

    Purpose: Cancer stem cells resistance to radiation is a problematic issue that has caused a big fail in cancer treatment. Methods: As a primary work, molecular imaging can indicate the main mechanisms of radiation resistance of cancer stem cells. By developing and commissioning new probes and nanomolecules and biomarkers, radiation scientist will able to identify the essential pathways of radiation resistance of cancer stem cells. As the second solution, molecular imaging is a best way to find biological target volume and delineate cancer stem cell tissues. In the other hand, by molecular imaging techniques one can image the treatment response in tumor and also in normal tissue. In this issue, the response of cancer stem cells to radiation during therapy course can be imaged, also the main mechanisms of radiation resistance and finding the best radiation modifiers (sensitizers) can be achieved by molecular imaging modalities. In adaptive radiotherapy the molecular imaging plays a vital role to have higher tumor control probability by delivering high radiation doses to cancer stem cells in any time of treatment. The outcome of a feasible treatment is dependent to high cancer stem cells response to radiation and removing all of which, so a good imaging modality can show this issue and preventing of tumor recurrence and metastasis. Results: Our results are dependent to use of molecular imaging as a new modality in the clinic. We propose molecular imaging as a new radiobiological technique to solve radiation therapy problems due to cancer stem cells. Conclusion: Molecular imaging guided cancer stem cell diagnosis and therapy is a new approach in the field of cancer treatment. This new radiobiological imaging technique should be developed in all clinics as a feasible tool that is more biological than physical imaging.

  7. Molecular mechanism for the umami taste synergism.

    Science.gov (United States)

    Zhang, Feng; Klebansky, Boris; Fine, Richard M; Xu, Hong; Pronin, Alexey; Liu, Haitian; Tachdjian, Catherine; Li, Xiaodong

    2008-12-30

    Umami is one of the 5 basic taste qualities. The umami taste of L-glutamate can be drastically enhanced by 5' ribonucleotides and the synergy is a hallmark of this taste quality. The umami taste receptor is a heteromeric complex of 2 class C G-protein-coupled receptors, T1R1 and T1R3. Here we elucidate the molecular mechanism of the synergy using chimeric T1R receptors, site-directed mutagenesis, and molecular modeling. We propose a cooperative ligand-binding model involving the Venus flytrap domain of T1R1, where L-glutamate binds close to the hinge region, and 5' ribonucleotides bind to an adjacent site close to the opening of the flytrap to further stabilize the closed conformation. This unique mechanism may apply to other class C G-protein-coupled receptors.

  8. Molecular mechanism of the sweet taste enhancers.

    Science.gov (United States)

    Zhang, Feng; Klebansky, Boris; Fine, Richard M; Liu, Haitian; Xu, Hong; Servant, Guy; Zoller, Mark; Tachdjian, Catherine; Li, Xiaodong

    2010-03-01

    Positive allosteric modulators of the human sweet taste receptor have been developed as a new way of reducing dietary sugar intake. Besides their potential health benefit, the sweet taste enhancers are also valuable tool molecules to study the general mechanism of positive allosteric modulations of T1R taste receptors. Using chimeric receptors, mutagenesis, and molecular modeling, we reveal how these sweet enhancers work at the molecular level. Our data argue that the sweet enhancers follow a similar mechanism as the natural umami taste enhancer molecules. Whereas the sweeteners bind to the hinge region and induce the closure of the Venus flytrap domain of T1R2, the enhancers bind close to the opening and further stabilize the closed and active conformation of the receptor.

  9. Estrogenic endocrine disruptors: Molecular mechanisms of action.

    Science.gov (United States)

    Kiyama, Ryoiti; Wada-Kiyama, Yuko

    2015-10-01

    A comprehensive summary of more than 450 estrogenic chemicals including estrogenic endocrine disruptors is provided here to understand the complex and profound impact of estrogen action. First, estrogenic chemicals are categorized by structure as well as their applications, usage and effects. Second, estrogenic signaling is examined by the molecular mechanism based on the receptors, signaling pathways, crosstalk/bypassing and autocrine/paracrine/homeostatic networks involved in the signaling. Third, evaluation of estrogen action is discussed by focusing on the technologies and protocols of the assays for assessing estrogenicity. Understanding the molecular mechanisms of estrogen action is important to assess the action of endocrine disruptors and will be used for risk management based on pathway-based toxicity testing.

  10. Molecular mechanism and regulation of autophagy

    Institute of Scientific and Technical Information of China (English)

    Ya-ping YANG; Zhong-qin LIANG; Zhen-lun GU; Zheng-hong QIN

    2005-01-01

    Autophagy is a major cellular pathway for the degradation of long-lived proteins and cytoplasmic organelles in eukaryotic cells. A large number of intracellular/extracellular stimuli, including amino acid starvation and invasion of microorganisms, are able to induce the autophagic response in cells. The discovery of the ATG genes in yeast has greatly advanced our understanding of the molecular mechanisms participating in autophagy and the genes involved in regulating the autophagic pathway. Many yeast genes have mammalian homologs,suggesting that the basic machinery for autophagy has been evolutionarily conserved along the eukaryotic phylum. The regulation of autophagy is a very complex process. Many signaling pathways, including target of rapamycin (TOR) or mammalian target of rapamycin (mTOR), phosphatidylinositol 3-kinase-I (PI3K-I)/PKB, GTPases, calcium and protein synthesis all play important roles in regulating autophagy. The molecular mechanisms and regulation of autophagy are discussed in this review.

  11. Mechanisms of inherited cancer susceptibility

    Institute of Scientific and Technical Information of China (English)

    Shirley HODGSON

    2008-01-01

    A small proportion of many cancers are due to inherited mutations in genes, which result in a high risk to the individual of developing specific cancers. There are several classes of genes that may be involved: tumour suppressor genes, oncogenes, genes encoding proteins involved in DNA repair and cell cycle control, and genes involved in stimulating the angiogenic pathway. Alterations in susceptibility to cancer may also be due to variations in genes involved in carcinogen metabolism. This review discusses examples of some of these genes and the associated clinical conditions caused by the inheritance of mutations in such genes.

  12. 胃癌细胞p16和CDK4的表达及调控的分子机制%Molecular mechanism of p16 and CDK4 expression and regulation in gastric cancer

    Institute of Scientific and Technical Information of China (English)

    马炬明; 王伟国; 胡慧珍; 施正杰

    2011-01-01

    目的 通过腺病毒携带p16基因感染胃癌细胞,研究p16功能恢复对CDK4表达的调节作用.方法 构建携带p16基因的重组腺病毒AdCMV-p16感染胃癌细胞系.Western blotting检测p16和CDK4的表达,MTT法检测癌细胞的增殖活性,DAPI染色计数癌细胞的凋亡比例.结果 胃癌细胞感染腺病毒载体AdCMV-p16后获得p16表达,对细胞整体CDK4表达无影响,但可明显降低细胞核CDK4的表达量;AdCMV-p16感染后引起癌细胞增殖活性下降,当感染复数(MOI)为1、10、20时,细胞存活率已经分别低于50%、20%和5%;p16表达可诱导癌细胞凋亡,细胞凋亡率达(13.86±4.65)%.结论 p16功能恢复后核CDK4含量减少,可能是诱导细胞周期阻滞和细胞凋亡、抑制癌细胞生长的主要分子机制.%Objective To investigate the regulation of CDK4 expression by reactivating p16 function through adenovirus vector in gastric cancer. Methods The adenovirus vector carrying p16 gene of AdCMV-p16 was constructed and used to infect gastric cancer cell lines. Western blotting was used to detect the expression of p16 and CDK4, MTT assay was used to detect the proliferation activity of cancer cells, and DAPI was used to stain and count the percentages of cancer cell apoptosis. Results After reactivation of p16 in gastric cancer cells, the expression level of CDK4 in whole cell extracts was not affected, but the nuclear CDK4 was decreased obviously. This phenomenon resulted in the depression of cancer cell proliferation activity, with the cell viability of lower than 50% ,20%, or 5% when MOl was 1, 10 or 20, respectively. p16 expression induced gastric cancer cells apoptosis with the apoptotic rate of ( 13. 86 ±4. 65)%. Conclusion The reactivation of p16 function in gastric cancer cells resulted in the decrease of nuclear CDK4,which may be the main molecular mechanism of pl6-induced cell cycle arrest and p16-mediated inhibition of cancer cell proliferation.

  13. Oral cancer: molecular technologies for risk assessment and diagnosis

    Institute of Scientific and Technical Information of China (English)

    Wan Tao Chen

    2008-01-01

    @@ Purpose: The effective biomarkers related to diagnosis, metastasis, drug resistance and irradiation sensitivity of oral cancers will help the pathologist and oncologist to determine the molecular taxonomy diagnosis and design the individualization treatment for the patients with oral cancers.

  14. Molecular Taxonomy and Tumourigenesis of Colorectal Cancer.

    Science.gov (United States)

    Biswas, S; Holyoake, D; Maughan, T S

    2016-02-01

    Over the last 5 years there has been a surge in interest in the molecular classification of colorectal cancer. The effect of molecular subtyping on current treatment decisions is limited to avoidance of adjuvant 5-fluorouracil chemotherapy in stage II microsatellite unstable-high disease and avoidance of epidermal growth factor receptor-targeted antibodies in extended RAS mutant tumours. The emergence of specific novel combination therapy for the BRAF-mutant cohort and of the microsatellite unstable-high cohort as a responsive group to immune checkpoint inhibition shows the growing importance of a clinically relevant molecular taxonomy. Clinical trials such as the Medical Research Council FOCUS4 trial using biomarkers to select patients for specific therapies are currently open and testing such approaches. The integration of mutation, gene expression and pathological analyses is refining our understanding of the biological subtypes within colorectal cancer. Sharing of data sets of parallel sequencing and gene expression of thousands of cancers among independent groups has allowed the description of disease subsets and the need for a validated consensus classification has become apparent. This biological understanding of the disease is a key step forward in developing a stratified approach to patient management. The discovery of stratifiers that predict a response to existing and emerging therapies will enable better use of these treatments. Improved scientific understanding of the biological characteristics of poorly responsive subgroups will facilitate the design of novel biologically rational combinations. Novel treatment regimens, including the combination of new drugs with radiation, and the discovery and validation of their associated predictive biomarkers will gradually lead to improved outcomes from therapy.

  15. Clinical Advances in Molecular Biomarkers for Cancer Diagnosis and Therapy

    OpenAIRE

    Sarkar, Fazlul H.; Philip, Philip A.; Seema Sethi; Shadan Ali

    2013-01-01

    Cancer diagnosis is currently undergoing a paradigm shift with the incorporation of molecular biomarkers as part of routine diagnostic panel. The molecular alteration ranges from those involving the DNA, RNA, microRNAs (miRNAs) and proteins. The miRNAs are recently discovered small non-coding endogenous single-stranded RNAs that critically regulates the development, invasion and metastasis of cancers. They are altered in cancers and have the potential to serve as diagnostic markers for cancer...

  16. Molecular markers for thyroid cancer diagnosis, prognosis, and targeted therapy.

    Science.gov (United States)

    Yip, Linwah

    2015-01-01

    Molecular markers including gene expression profiles, somatic gene alterations, and circulating peripheral markers have augmented diagnostic, prognostic, and therapeutic options for thyroid cancer patients.

  17. Molecular profiling of childhood cancer: Biomarkers and novel therapies

    Directory of Open Access Journals (Sweden)

    Federica Saletta

    2014-06-01

    General significance: The increasing recognition of the heterogeneity of molecular causes of cancer favors the continued development of molecularly targeted agents, and their transfer to pediatric and adolescent populations.

  18. Antineoplastic mechanisms of Iodine in cancers that take up Iodine

    Directory of Open Access Journals (Sweden)

    Carmen Aceves

    2015-12-01

    Full Text Available Purpose: In addition to being a component of thyroid hormone (TH, iodine can be an antioxidant as well as an antiproliferative and differentiation agent that helps to maintain the integrity of several organs with the ability to take up iodine.Methods and Results: Studies from our laboratory shown that in preclinical (cell culture, induced animal cancer and xenographs and clinical studies (mammary cancer protocol, molecular iodine (I2 supplementation exerts suppressive effects on implantation, development, and progression of cancer neoplasias. These effects can be mediated by a variety of mechanisms and pathways, including direct actions, in which the oxidized iodine modulates the immune/tumor response and through iodolipid formation and the activation of peroxisome proliferator-activated receptors type gamma (PPARγ triggering apoptotic and/or differentiation pathways.Conclusion: The absence of side effects and the easy availability and handling of I2 have allowed the establishment of clinical protocols to utilize I2 supplementation as an adjuvant in therapies against cancers that take up iodine.-----------------------------------------Cite this article as:  Aceves C, Anguiano B. Antineoplastic mechanisms of Iodine in cancers that take up Iodine. Int J Cancer Ther Oncol 2015; 3(4:3401.[This abstract was presented at the BIT’s 8th Annual World Cancer Congress, which was held from May 15-17, 2015 in Beijing, China.

  19. Breast cancer and possible mechanisms of therapy resistance

    Directory of Open Access Journals (Sweden)

    Ana-Maria Florea

    2013-03-01

    Full Text Available Breast cancer represents one of the most common cancers in women and is a major life threatening illness found all over the world. Therapy approaches include irradiation and surgery, with chemotherapy considered an important strategy to treat breast cancer. Platinum based anticancer drugs, such as cisplatin (cis-di-amino-dichloride-platin, CDDP, carboplatin, orthoplatin, etc., have been successfully used in breast cancer therapy because they activate multiple mechanisms to induce apoptosis in tumor cells. Nevertheless, during chemotherapy, drug resistance frequently develops; this impairs the successful treatment of breast cancer and often leads to patients’ decease. While combinations of anticancer drugs used in chemotherapy regimens reduced the occurrence of drug resistance (e.g. doxorubicin + docetaxel, doxorubicin + cyclophosphamide, docetaxel + herceptin + carboplatin the molecular mechanism of those effects are not completely understood. Here we review possible mechanisms related to breast cancer treatment and resistance to current therapies as well as possible new therapeutic targets (e.g. calcium signaling which could be used in the future.

  20. Molecular mechanisms for protein-encoded inheritance

    Energy Technology Data Exchange (ETDEWEB)

    Wiltzius, Jed J.W.; Landau, Meytal; Nelson, Rebecca; Sawaya, Michael R.; Apostol, Marcin I.; Goldschmidt, Lukasz; Soriaga, Angela B.; Cascio, Duilio; Rajashankar, Kanagalaghatta; Eisenberg, David; (Cornell); (HHMI)

    2009-12-01

    In prion inheritance and transmission, strains are phenotypic variants encoded by protein 'conformations'. However, it is unclear how a protein conformation can be stable enough to endure transmission between cells or organisms. Here we describe new polymorphic crystal structures of segments of prion and other amyloid proteins, which offer two structural mechanisms for the encoding of prion strains. In packing polymorphism, prion strains are encoded by alternative packing arrangements (polymorphs) of {beta}-sheets formed by the same segment of a protein; in segmental polymorphism, prion strains are encoded by distinct {beta}-sheets built from different segments of a protein. Both forms of polymorphism can produce enduring conformations capable of encoding strains. These molecular mechanisms for transfer of protein-encoded information into prion strains share features with the familiar mechanism for transfer of nucleic acid-encoded information into microbial strains, including sequence specificity and recognition by noncovalent bonds.

  1. Molecular mechanisms for protein-encoded inheritance.

    Science.gov (United States)

    Wiltzius, Jed J W; Landau, Meytal; Nelson, Rebecca; Sawaya, Michael R; Apostol, Marcin I; Goldschmidt, Lukasz; Soriaga, Angela B; Cascio, Duilio; Rajashankar, Kanagalaghatta; Eisenberg, David

    2009-09-01

    In prion inheritance and transmission, strains are phenotypic variants encoded by protein 'conformations'. However, it is unclear how a protein conformation can be stable enough to endure transmission between cells or organisms. Here we describe new polymorphic crystal structures of segments of prion and other amyloid proteins, which offer two structural mechanisms for the encoding of prion strains. In packing polymorphism, prion strains are encoded by alternative packing arrangements (polymorphs) of beta-sheets formed by the same segment of a protein; in segmental polymorphism, prion strains are encoded by distinct beta-sheets built from different segments of a protein. Both forms of polymorphism can produce enduring conformations capable of encoding strains. These molecular mechanisms for transfer of protein-encoded information into prion strains share features with the familiar mechanism for transfer of nucleic acid-encoded information into microbial strains, including sequence specificity and recognition by noncovalent bonds.

  2. Molecular Link between Vitamin D and Cancer Prevention

    Directory of Open Access Journals (Sweden)

    William B. Grant

    2013-09-01

    Full Text Available The metabolite of vitamin D, 1α,25-dihydroxyvitamin D3 (also known as calcitriol, is a biologically active molecule required to maintain the physiological functions of several target tissues in the human body from conception to adulthood. Its molecular mode of action ranges from immediate nongenomic responses to longer term mechanisms that exert persistent genomic effects. The genomic mechanisms of vitamin D action rely on cross talk between 1α,25-dihydroxyvitamin D3 signaling pathways and that of other growth factors or hormones that collectively regulate cell proliferation, differentiation and cell survival. In vitro and in vivo studies demonstrate a role for vitamin D (calcitriol in modulating cellular growth and development. Vitamin D (calcitriol acts as an antiproliferative agent in many tissues and significantly slows malignant cellular growth. Moreover, epidemiological studies have suggested that ultraviolet-B exposure can help reduce cancer risk and prevalence, indicating a potential role for vitamin D as a feasible agent to prevent cancer incidence and recurrence. With the preventive potential of this biologically active agent, we suggest that countries where cancer is on the rise—yet where sunlight and, hence, vitamin D may be easily acquired—adopt awareness, education and implementation strategies to increase supplementation with vitamin D in all age groups as a preventive measure to reduce cancer risk and prevalence.

  3. Epigenetic: a molecular link between testicular cancer and environmental exposures?

    Directory of Open Access Journals (Sweden)

    Aurelie eVega

    2012-11-01

    Full Text Available In the last decades, studies in rodents have highlighted links between in utero and/or neonatal exposures to molecules that alter endocrine functions and the development of genital tract abnormalities, such as cryptorchidism, hypospadias, and impaired spermatogenesis. Most of these molecules, called endocrine disrupters (EDs exert estrogenic and/or antiandrogenic activities. These data led to the hypothesis of the Testicular Dysgenesis Syndrome which postulates that these disorders are one clinical entity and are linked by epidemiological and pathophysiological relations. Futhermore, infertility has been stated as a risk factor for testicular cancer. The incidence of testicular cancer has been increasing over the past decades. Most of testicular germ cell cancers develop through a pre-invasive carcinoma in situ (CIS from fetal germ cells (primordial germ cell or gonocyte. During their development, fetal germ cells undergo epigenetic modifications. Interestingly, several lines of evidence have shown that gene regulation through epigenetic mechanisms (DNA and histone modifications plays an important role in normal development as well as in various diseases, including testicular cancer.Here we will review chromatin modifications which can affect testicular physiology leading to the development of testicular cancer; and highlight potential molecular pathways involved in these alterations in the context of environmental exposures.

  4. Understanding the molecular pathogenesis and prognostics of bladder cancer: an overview.

    Science.gov (United States)

    Zhao, Ming; He, Xiang-Lei; Teng, Xiao-Dong

    2016-02-01

    The knowledge of cellular mechanisms in malignances of the bladder has grown exponentially. Molecular technologies have led to the discovery of the molecular pathways distinguishing low-and high-grade urothelial neoplasms. This trend portends the future in which the classification and diagnosis of the bladder tumors through morphologic analysis will be supported by molecular information correlating with prognosis and targeted therapy. This article outlines tumor molecular pathology of bladder cancer with an emphasis on several promising candidate biomarkers that may soon make their transition to the realm of clinical management of bladder cancer.

  5. Molecular model with quantum mechanical bonding information.

    Science.gov (United States)

    Bohórquez, Hugo J; Boyd, Russell J; Matta, Chérif F

    2011-11-17

    The molecular structure can be defined quantum mechanically thanks to the theory of atoms in molecules. Here, we report a new molecular model that reflects quantum mechanical properties of the chemical bonds. This graphical representation of molecules is based on the topology of the electron density at the critical points. The eigenvalues of the Hessian are used for depicting the critical points three-dimensionally. The bond path linking two atoms has a thickness that is proportional to the electron density at the bond critical point. The nuclei are represented according to the experimentally determined atomic radii. The resulting molecular structures are similar to the traditional ball and stick ones, with the difference that in this model each object included in the plot provides topological information about the atoms and bonding interactions. As a result, the character and intensity of any given interatomic interaction can be identified by visual inspection, including the noncovalent ones. Because similar bonding interactions have similar plots, this tool permits the visualization of chemical bond transferability, revealing the presence of functional groups in large molecules.

  6. Fecal Molecular Markers for Colorectal Cancer Screening

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    Rani Kanthan

    2012-01-01

    Full Text Available Despite multiple screening techniques, including colonoscopy, flexible sigmoidoscopy, radiological imaging, and fecal occult blood testing, colorectal cancer remains a leading cause of death. As these techniques improve, their sensitivity to detect malignant lesions is increasing; however, detection of precursor lesions remains problematic and has generated a lack of general acceptance for their widespread usage. Early detection by an accurate, noninvasive, cost-effective, simple-to-use screening technique is central to decreasing the incidence and mortality of this disease. Recent advances in the development of molecular markers in faecal specimens are encouraging for its use as a screening tool. Genetic mutations and epigenetic alterations that result from the carcinogenetic process can be detected by coprocytobiology in the colonocytes exfoliated from the lesion into the fecal matter. These markers have shown promising sensitivity and specificity in the detection of both malignant and premalignant lesions and are gaining popularity as a noninvasive technique that is representative of the entire colon. In this paper, we summarize the genetic and epigenetic fecal molecular markers that have been identified as potential targets in the screening of colorectal cancer.

  7. Glucose restriction induces cell death in parental but not in homeodomain-interacting protein kinase 2-depleted RKO colon cancer cells: molecular mechanisms and implications for tumor therapy.

    Science.gov (United States)

    Garufi, A; Ricci, A; Trisciuoglio, D; Iorio, E; Carpinelli, G; Pistritto, G; Cirone, M; D'Orazi, G

    2013-05-23

    Tumor cell tolerance to nutrient deprivation can be an important factor for tumor progression, and may depend on deregulation of both oncogenes and oncosuppressor proteins. Homeodomain-interacting protein kinase 2 (HIPK2) is an oncosuppressor that, following its activation by several cellular stress, induces cancer cell death via p53-dependent or -independent pathways. Here, we used genetically matched human RKO colon cancer cells harboring wt-HIPK2 (HIPK2(+/+)) or stable HIPK2 siRNA interference (siHIPK2) to investigate in vitro whether HIPK2 influenced cell death in glucose restriction. We found that glucose starvation induced cell death, mainly due to c-Jun NH2-terminal kinase activation, in HIPK2(+/+)cells compared with siHIPK2 cells that did not die. (1)H-nuclear magnetic resonance quantitative metabolic analyses showed a marked glycolytic activation in siHIPK2 cells. However, treatment with glycolysis inhibitor 2-deoxy-D-glucose induced cell death only in HIPK2(+/+) cells but not in siHIPK2 cells. Similarly, siGlut-1 interference did not re-establish siHIPK2 cell death under glucose restriction, whereas marked cell death was reached only after zinc supplementation, a condition known to reactivate misfolded p53 and inhibit the pseudohypoxic phenotype in this setting. Further siHIPK2 cell death was reached with zinc in combination with autophagy inhibitor. We propose that the metabolic changes acquired by cells after HIPK2 silencing may contribute to induce resistance to cell death in glucose restriction condition, and therefore be directly relevant for tumor progression. Moreover, elimination of such a tolerance might serve as a new strategy for cancer therapy.

  8. Dissecting molecular mechanisms in the living brain of dementia patients.

    Science.gov (United States)

    Barrio, Jorge R; Satyamurthy, Nagichettiar; Huang, Sung-Cheng; Petric, Andrej; Small, Gary W; Kepe, Vladimir

    2009-07-21

    Understanding the molecular mechanisms associated with the development of dementia is essential for designing successful interventions. Dementia, like cancer and cardiovascular disease, requires early detection to potentially arrest or prevent further disease progression. By the time a neurologist begins to manage clinical symptoms, the disease has often damaged the brain significantly. Because successful treatment is the logical goal, detecting the disease when brain damage is still limited is of the essence. The role of chemistry in this discovery process is critical. With the advent of molecular imaging, the understanding of molecular mechanisms in human neurodegenerative diseases has exploded. Traditionally, knowledge of enzyme and neurotransmitter function in humans has been extrapolated from animal studies, but now we can acquire data directly from both healthy and diseased human subjects. In this Account, we describe the use of molecular imaging probes to elucidate the biochemical and cellular bases of dementia (e.g., Alzheimer's disease) and the application of these discoveries to the design of successful therapeutic interventions. Molecular imaging permits observation and evaluation of the basic molecular mechanisms of disease progression in the living brains of patients. 2-Deoxy-2-[(18)F]fluoro-d-glucose is used to assess the effect of Alzheimer's disease progression on neuronal circuits projecting from and to the temporal lobe (one of the earliest metabolic signs of the disease). Recently, we have developed imaging probes for detection of amyloid neuropathology (both tau and beta-amyloid peptide deposits) and neuronal losses. These probes allow us to visualize the development of pathology in the living brain of dementia patients and its consequences, such as losses of critical neurons associated with memory deficits and other neuropsychiatric impairments. Because inflammatory processes are tightly connected to the brain degenerative processes

  9. Molecular mechanics conformational analysis of tylosin

    Science.gov (United States)

    Ivanov, Petko M.

    1998-01-01

    The conformations of the 16-membered macrolide antibiotic tylosin were studied with molecular mechanics (AMBER∗ force field) including modelling of the effect of the solvent on the conformational preferences (GB/SA). A Monte Carlo conformational search procedure was used for finding the most probable low-energy conformations. The present study provides complementary data to recently reported analysis of the conformations of tylosin based on NMR techniques. A search for the low-energy conformations of protynolide, a 16-membered lactone containing the same aglycone as tylosin, was also carried out, and the results were compared with the observed conformation in the crystal as well as with the most probable conformations of the macrocyclic ring of tylosin. The dependence of the results on force field was also studied by utilizing the MM3 force field. Some particular conformations were computed with the semiempirical molecular orbital methods AM1 and PM3.

  10. Molecular mechanisms of resistance to the EGFR monoclonal antibody cetuximab.

    Science.gov (United States)

    Brand, Toni M; Iida, Mari; Wheeler, Deric L

    2011-05-01

    The epidermal growth factor receptor (EGFR) is a receptor tyrosine kinase belonging to the HER family of receptor tyrosine kinases. Receptor activation upon ligand binding leads to down stream activation of the PI3K/AKT, RAS/RAF/MEK/ERK and PLCγ/PKC pathways that influence cell proliferation, survival and the metastatic potential of tumor cells. Increased activation by gene amplification, protein overexpression or mutations of the EGFR has been identified as an etiological factor in a number of human epithelial cancers (e.g., NSCLC, CRC, glioblastoma and breast cancer). Therefore, targeting the EGFR has been intensely pursued as a cancer treatment strategy over the last two decades. To date, five EGFR inhibitors, including three small molecule tyrosine kinase inhibitors (TKIs) and two monoclonal antibodies have gained FDA approval for use in oncology. Both approaches to targeting the EGFR have shown clinical promise and the anti-EGFR antibody cetuximab is used to treat HNSCC and CRC. Despite clinical gains arising from use of cetuximab, both intrinsic resistance and the development of acquired resistance are now well recognized. In this review we focus on the biology of the EGFR, the role of EGFR in human cancer, the development of antibody-based anti-EGFR therapies and a summary of their clinical successes. Further, we provide an in depth discussion of described molecular mechanisms of resistance to cetuximab and potential strategies to circumvent this resistance.

  11. Inhibitory effects of polyphenol-enriched extract from Ziyang tea against human breast cancer MCF-7 cells through reactive oxygen species-dependent mitochondria molecular mechanism

    Directory of Open Access Journals (Sweden)

    Wenfeng Li

    2016-07-01

    Full Text Available A polyphenol-enriched extract from selenium-enriched Ziyang green tea (ZTP was selected to evaluate its antitumor effects against human breast cancer MCF-7 cells. In ZTP, (−-epigallocatechin gallate (28.2% was identified as the major catechin, followed by (−-epigallocatechin (5.7% and (−-epicatechin gallate (12.6%. ZTP was shown to inhibit MCF-7 cell proliferation (half maximal inhibitory concentration, IC50 = 172.2 μg/mL by blocking cell-cycle progression at the G0/G1 phase and inducing apoptotic death. Western blotting assay indicated that ZTP induced cell-cycle arrest by upregulation of p53 and reduced the expression of CDK2 in MCF-7 cells. ZTP-caused cell apoptosis was associated with an increase in Bax/Bcl-2 ratio, and activation of caspase-3 and -9. MCF-7 cells treated with ZTP also showed an overproduction of reactive oxygen species, suggesting that reactive oxygen species played an important role in the induction of apoptosis in MCF-7 cells. This is the first report showing that ZTP is a potential novel dietary agent for cancer chemoprevention or chemotherapy.

  12. Modeling molecular mechanisms in the axon

    Science.gov (United States)

    de Rooij, R.; Miller, K. E.; Kuhl, E.

    2017-03-01

    Axons are living systems that display highly dynamic changes in stiffness, viscosity, and internal stress. However, the mechanistic origin of these phenomenological properties remains elusive. Here we establish a computational mechanics model that interprets cellular-level characteristics as emergent properties from molecular-level events. We create an axon model of discrete microtubules, which are connected to neighboring microtubules via discrete crosslinking mechanisms that obey a set of simple rules. We explore two types of mechanisms: passive and active crosslinking. Our passive and active simulations suggest that the stiffness and viscosity of the axon increase linearly with the crosslink density, and that both are highly sensitive to the crosslink detachment and reattachment times. Our model explains how active crosslinking with dynein motors generates internal stresses and actively drives axon elongation. We anticipate that our model will allow us to probe a wide variety of molecular phenomena—both in isolation and in interaction—to explore emergent cellular-level features under physiological and pathological conditions.

  13. Molecular mechanisms of sex determination in reptiles.

    Science.gov (United States)

    Rhen, T; Schroeder, A

    2010-01-01

    Charles Darwin first provided a lucid explanation of how gender differences evolve nearly 140 years ago. Yet, a disconnect remains between his theory of sexual selection and the mechanisms that underlie the development of males and females. In particular, comparisons between representatives of different phyla (i.e., flies and mice) reveal distinct genetic mechanisms for sexual differentiation. Such differences are hard to comprehend unless we study organisms that bridge the phylogenetic gap. Analysis of variation within monophyletic groups (i.e., amniotes) is just as important if we hope to elucidate the evolution of mechanisms underlying sexual differentiation. Here we review the molecular, cellular, morphological, and physiological changes associated with sex determination in reptiles. Most research on the molecular biology of sex determination in reptiles describes expression patterns for orthologs of mammalian sex-determining genes. Many of these genes have evolutionarily conserved expression profiles (i.e., DMRT1 and SOX9 are expressed at a higher level in developing testes vs. developing ovaries in all species), which suggests functional conservation. However, expression profiling alone does not test gene function and will not identify novel sex-determining genes or gene interactions. For that reason, we provide a prospectus on various techniques that promise to reveal new sex-determining genes and regulatory interactions among these genes. We offer specific examples of novel candidate genes and a new signaling pathway in support of these techniques.

  14. Thymic Output: Influence Factors and Molecular Mechanism

    Institute of Scientific and Technical Information of China (English)

    Rong Jin; Jun Zhang; Weifeng Chen

    2006-01-01

    Thymus is a primary lymphoid organ, able to generate mature T cells that eventually colonize secondary lymphoid organs, and is therefore essential for peripheral T cell renewal. Recent data showed that normal thymocyte export can be altered by several influence factors including several chemokines,sphingosinel-phosphate (S1P),transcription factors such as Foxjl, Kruppel-like transcription factor 2 (KLF2) and antigen stimulation, etc. In this review, we summarized the recent reports about study strategies, influence factors and possible molecular mechanisms in thymic output.

  15. Molecular mechanism of size control in development and human diseases

    Institute of Scientific and Technical Information of China (English)

    Xiaolong Yang; Tian Xu

    2011-01-01

    How multicellular organisms control their size is a fundamental question that fascinated generations of biologists.In the past 10 years, tremendous progress has been made toward our understanding of the molecular mechanism underlying size control. Original studies from Drosophila showed that in addition to extrinsic nutritional and hormonal cues, intrinsic mechanisms also play important roles in the control of organ size during development. Several novel signaling pathways such as insulin and Hippo-LATS signaling pathways have been identified that control organ size by regulating cell size and/or cell number through modulation of cell growth, cell division, and cell death. Later studies using mammalian cell and mouse models also demonstrated that the signaling pathways identified in flies are also conserved in mammals. Significantly, recent studies showed that dysregulation of size control plays important roles in the development of many human diseases sucha as cancer,diabetes,and hypertrophy.

  16. Molecular mechanisms of glucocorticoid receptor signaling

    Directory of Open Access Journals (Sweden)

    Marta Labeur

    2010-10-01

    Full Text Available This review highlights the most recent findings on the molecular mechanisms of the glucocorticoid receptor (GR. Most effects of glucocorticoids are mediated by the intracellular GR which is present in almost every tissue and controls transcriptional activation via direct and indirect mechanisms. Nevertheless the glucocorticoid responses are tissue -and gene- specific. GR associates selectively with corticosteroid ligands produced in the adrenal gland in response to changes of humoral homeostasis. Ligand interaction with GR promotes either GR binding to genomic glucocorticoid response elements, in turn modulating gene transcription, or interaction of GR monomers with other transcription factors activated by other signalling pathways leading to transrepression. The GR regulates a broad spectrum of physiological functions, including cell differentiation, metabolism and inflammatory responses. Thus, disruption or dysregulation of GR function will result in severe impairments in the maintenance of homeostasis and the control of adaptation to stress.

  17. [Molecular mechanisms regulating the activity of macrophages].

    Science.gov (United States)

    Onoprienko, L V

    2011-01-01

    This article reviews modern concepts of the most common types of macrophage activation: classical, alternative, and type II. Molecular mechanisms of induction and regulation of these three types of activation are discussed. Any population of macrophages was shown to change its properties depending on its microenvironment and concrete biological situation (the "functional plasticity of macrophages"). Many intermediate states of macrophages were described along with the most pronounced and well-known activation types (classical activation, alternative activation, and type II activation). These intermediate states are characterized by a variety of combinations of their biological properties, including elements of the three afore mentioned types of activation. Macrophage activity is regulated by a complex network of interrelated cascade mechanisms.

  18. Multiscale Quantum Mechanics/Molecular Mechanics Simulations with Neural Networks.

    Science.gov (United States)

    Shen, Lin; Wu, Jingheng; Yang, Weitao

    2016-10-11

    Molecular dynamics simulation with multiscale quantum mechanics/molecular mechanics (QM/MM) methods is a very powerful tool for understanding the mechanism of chemical and biological processes in solution or enzymes. However, its computational cost can be too high for many biochemical systems because of the large number of ab initio QM calculations. Semiempirical QM/MM simulations have much higher efficiency. Its accuracy can be improved with a correction to reach the ab initio QM/MM level. The computational cost on the ab initio calculation for the correction determines the efficiency. In this paper we developed a neural network method for QM/MM calculation as an extension of the neural-network representation reported by Behler and Parrinello. With this approach, the potential energy of any configuration along the reaction path for a given QM/MM system can be predicted at the ab initio QM/MM level based on the semiempirical QM/MM simulations. We further applied this method to three reactions in water to calculate the free energy changes. The free-energy profile obtained from the semiempirical QM/MM simulation is corrected to the ab initio QM/MM level with the potential energies predicted with the constructed neural network. The results are in excellent accordance with the reference data that are obtained from the ab initio QM/MM molecular dynamics simulation or corrected with direct ab initio QM/MM potential energies. Compared with the correction using direct ab initio QM/MM potential energies, our method shows a speed-up of 1 or 2 orders of magnitude. It demonstrates that the neural network method combined with the semiempirical QM/MM calculation can be an efficient and reliable strategy for chemical reaction simulations.

  19. Early-onset gastric cancers have a different molecular expression profile than conventional gastric cancers

    NARCIS (Netherlands)

    A.N.A. Milne; R. Carvalho; F.M. Morsink; A.R. Musler; W.W.J. de Leng; A. Ristimaki; G.J.A. Offerhaus

    2006-01-01

    Many studies examine the molecular genetics of gastric cancer, but few look at young patients in particular and there is no comparison of molecular expression between early-onset gastric cancer (<= 45 years old) and conventional gastric cancers. Expression of cycloxygenase-2 (COX-2) is elevated in g

  20. Molecular Mechanisms Regulating Macrophage Response to Hypoxia

    Directory of Open Access Journals (Sweden)

    Michal Amit Rahat

    2011-09-01

    Full Text Available Monocytes and Macrophages (Mo/Mϕ exhibit great plasticity, as they can shift between different modes of activation and, driven by their immediate microenvironment, perform divergent functions. These include, among others, patrolling their surroundings and maintaining homeostasis (resident Mo/Mϕ, combating invading pathogens and tumor cells (classically activated or M1 Mo/Mϕ, orchestrating wound healing (alternatively activated or M2 Mo/Mϕ, and restoring homeostasis after an inflammatory response (resolution Mϕ. Hypoxia is an important factor in the Mϕ microenvironment, is prevalent in many physiological and pathological conditions, and is interdependent with the inflammatory response. Although Mo/Mϕ have been studied in hypoxia, the mechanisms by which hypoxia influences the different modes of their activation, and how it regulates the shift between them, remain unclear. Here we review the current knowledge about the molecular mechanisms that mediate this hypoxic regulation of Mϕ activation. Much is known about the hypoxic transcriptional regulatory network, which includes the master regulators HIF-1 and NF-κB, as well as other transcription factors (e.g. AP-1, Erg-1, but we also highlight the role of post-transcriptional and post-translational mechanisms. These mechanisms mediate hypoxic induction of Mϕ pro-angiogenic mediators, suppress M1 Mϕ by post-transcriptionally inhibiting pro-inflammatory mediators, and help shift the classically activated Mϕ into an activation state which approximate the alternatively activated or resolution Mϕ.

  1. Hormonal and molecular aspects of endometrioid endometrial cancer

    NARCIS (Netherlands)

    Jongen, Vincentius Hubertus Willibrordus Maria

    2008-01-01

    This thesis concerns the expression and prognostic value of various hormones and molecular markers playing a role n endometrioid endometrial cancer. Especially we were interested in the enzyme aromatase, its expression and (prognostic) role in endometrioid endometrial cancer. Endometrial cancer is t

  2. Cellular and molecular mechanisms of muscle atrophy

    Directory of Open Access Journals (Sweden)

    Paolo Bonaldo

    2013-01-01

    Full Text Available Skeletal muscle is a plastic organ that is maintained by multiple pathways regulating cell and protein turnover. During muscle atrophy, proteolytic systems are activated, and contractile proteins and organelles are removed, resulting in the shrinkage of muscle fibers. Excessive loss of muscle mass is associated with poor prognosis in several diseases, including myopathies and muscular dystrophies, as well as in systemic disorders such as cancer, diabetes, sepsis and heart failure. Muscle loss also occurs during aging. In this paper, we review the key mechanisms that regulate the turnover of contractile proteins and organelles in muscle tissue, and discuss how impairments in these mechanisms can contribute to muscle atrophy. We also discuss how protein synthesis and degradation are coordinately regulated by signaling pathways that are influenced by mechanical stress, physical activity, and the availability of nutrients and growth factors. Understanding how these pathways regulate muscle mass will provide new therapeutic targets for the prevention and treatment of muscle atrophy in metabolic and neuromuscular diseases.

  3. Molecular Markers with Predictive and Prognostic Relevance in Lung Cancer

    Directory of Open Access Journals (Sweden)

    Alphy Rose-James

    2012-01-01

    Full Text Available Lung cancer accounts for the majority of cancer-related deaths worldwide of which non-small-cell lung carcinoma alone takes a toll of around 85%. Platinum-based therapy is the stronghold for lung cancer at present. The discovery of various molecular alterations that underlie lung cancer has contributed to the development of specifically targeted therapies employing specific mutation inhibitors. Targeted chemotherapy based on molecular profiling has shown great promise in lung cancer treatment. Various molecular markers with predictive and prognostic significance in lung cancer have evolved as a result of advanced research. Testing of EGFR and Kras mutations is now a common practice among community oncologists, and more recently, ALK rearrangements have been added to this group. This paper discusses various predictive and prognostic markers that are being investigated and have shown significant relevance which can be exploited for targeted treatment in lung cancer.

  4. Conjugated linoleic acids (CLAs) decrease prostate cancer cell proliferation: different molecular mechanisms for cis-9, trans-11 and trans-10, cis-12 isomers.

    Science.gov (United States)

    Ochoa, Julio J; Farquharson, Andrew J; Grant, Ian; Moffat, L E; Heys, Steven D; Wahle, Klaus W J

    2004-07-01

    The aims of this study were to examine the anti-proliferative effects of different concentrations of a commercial preparation of conjugated linoleic acids (CLA) mixture of isomers [cis-9, trans-11 CLA (c9,t11 CLA): trans-10, cis-12 CLA (50:50)] and their constituent isomers on PC-3, a human prostatic carcinoma cell line, and to study their effects on gene expression (mRNA and protein levels) of different enzymes and oncoproteins involved in oncogenesis and progression of prostate cancer. This includes pathways for arachidonic acid metabolism [cyclooxygenase 1 (COX-1), 2 (COX-2) and 5-lipoxygenase (5-LOX)], apoptosis (bcl-2) and cell cycle control (p21(WAF/Cip1)). Our results indicate a significant decrease in PC-3 proliferation elicited by CLA, although with high variability between isomers. The trans-10, cis-12 CLA was the most effective isomer (55% inhibition). This isomer was also able to decrease bcl-2 gene expression and to increase p21(WAF1/Cip1) mRNA levels (60% increase at highest concentration). In contrast, cis-9, trans-11 had no effect on these proteins but had a clear effect on 5-LOX expression and to a lesser degree on COX-2 protein level isomers. In conclusion, the anti-proliferative effects on PC-3 of CLA mixture and their constituent isomers are not equivalent, due to the different pathways involved for individual isomers. Trans-10, cis-12 seems to work preferentially through modulation of apoptosis and cell cycle control, while c9,t11 CLA isomer affects arachidonic acid metabolism.

  5. The iron chelator, deferasirox, as a novel strategy for cancer treatment: oral activity against human lung tumor xenografts and molecular mechanism of action.

    Science.gov (United States)

    Lui, Goldie Y L; Obeidy, Peyman; Ford, Samuel J; Tselepis, Chris; Sharp, Danae M; Jansson, Patric J; Kalinowski, Danuta S; Kovacevic, Zaklina; Lovejoy, David B; Richardson, Des R

    2013-01-01

    Deferasirox is an orally effective iron (Fe) chelator currently used for the treatment of iron-overload disease and has been implemented as an alternative to the gold standard chelator, desferrioxamine (DFO). Earlier studies demonstrated that DFO exhibits anticancer activity due to its ability to deplete cancer cells of iron. In this investigation, we examined the in vitro and in vivo activity of deferasirox against cells from human solid tumors. To date, there have been no studies to investigate the effect of deferasirox on these types of tumors in vivo. Deferasirox demonstrated similar activity at inhibiting proliferation of DMS-53 lung carcinoma and SK-N-MC neuroepithelioma cell lines compared with DFO. Furthermore, deferasirox was generally similar or slightly more effective than DFO at mobilizing cellular (59)Fe and inhibiting iron uptake from human transferrin depending on the cell type. However, deferasirox potently inhibited DMS-53 xenograft growth in nude mice when given by oral gavage, with no marked alterations in normal tissue histology. To understand the antitumor activity of deferasirox, we investigated its effect on the expression of molecules that play key roles in metastasis, cell cycle control, and apoptosis. We demonstrated that deferasirox increased expression of the metastasis suppressor protein N-myc downstream-regulated gene 1 and upregulated the cyclin-dependent kinase inhibitor p21(CIP1/WAF1) while decreasing cyclin D1 levels. Moreover, this agent increased the expression of apoptosis markers, including cleaved caspase-3 and cleaved poly(ADP-ribose) polymerase 1. Collectively, we demonstrate that deferasirox is an orally effective antitumor agent against solid tumors.

  6. Quantum mechanics/molecular mechanics dual Hamiltonian free energy perturbation.

    Science.gov (United States)

    Polyak, Iakov; Benighaus, Tobias; Boulanger, Eliot; Thiel, Walter

    2013-08-14

    The dual Hamiltonian free energy perturbation (DH-FEP) method is designed for accurate and efficient evaluation of the free energy profile of chemical reactions in quantum mechanical/molecular mechanical (QM/MM) calculations. In contrast to existing QM/MM FEP variants, the QM region is not kept frozen during sampling, but all degrees of freedom except for the reaction coordinate are sampled. In the DH-FEP scheme, the sampling is done by semiempirical QM/MM molecular dynamics (MD), while the perturbation energy differences are evaluated from high-level QM/MM single-point calculations at regular intervals, skipping a pre-defined number of MD sampling steps. After validating our method using an analytic model potential with an exactly known solution, we report a QM/MM DH-FEP study of the enzymatic reaction catalyzed by chorismate mutase. We suggest guidelines for QM/MM DH-FEP calculations and default values for the required computational parameters. In the case of chorismate mutase, we apply the DH-FEP approach in combination with a single one-dimensional reaction coordinate and with a two-dimensional collective coordinate (two individual distances), with superior results for the latter choice.

  7. Animal models and therapeutic molecular targets of cancer: utility and limitations

    Directory of Open Access Journals (Sweden)

    Cekanova M

    2014-10-01

    Full Text Available Maria Cekanova, Kusum Rathore Department of Small Animal Clinical Sciences, College of Veterinary Medicine, The University of Tennessee, Knoxville, TN, USA Abstract: Cancer is the term used to describe over 100 diseases that share several common hallmarks. Despite prevention, early detection, and novel therapies, cancer is still the second leading cause of death in the USA. Successful bench-to-bedside translation of basic scientific findings about cancer into therapeutic interventions for patients depends on the selection of appropriate animal experimental models. Cancer research uses animal and human cancer cell lines in vitro to study biochemical pathways in these cancer cells. In this review, we summarize the important animal models of cancer with focus on their advantages and limitations. Mouse cancer models are well known, and are frequently used for cancer research. Rodent models have revolutionized our ability to study gene and protein functions in vivo and to better understand their molecular pathways and mechanisms. Xenograft and chemically or genetically induced mouse cancers are the most commonly used rodent cancer models. Companion animals with spontaneous neoplasms are still an underexploited tool for making rapid advances in human and veterinary cancer therapies by testing new drugs and delivery systems that have shown promise in vitro and in vivo in mouse models. Companion animals have a relatively high incidence of cancers, with biological behavior, response to therapy, and response to cytotoxic agents similar to those in humans. Shorter overall lifespan and more rapid disease progression are factors contributing to the advantages of a companion animal model. In addition, the current focus is on discovering molecular targets for new therapeutic drugs to improve survival and quality of life in cancer patients. Keywords: mouse cancer model, companion animal cancer model, dogs, cats, molecular targets

  8. Vibrational spectrum at a water surface: a hybrid quantum mechanics/molecular mechanics molecular dynamics approach.

    Science.gov (United States)

    Ishiyama, Tatsuya; Takahashi, Hideaki; Morita, Akihiro

    2012-03-28

    A hybrid quantum mechanics/molecular mechanics (QM/MM) molecular dynamics (MD) simulation is applied to the calculation of surface orientational structure and vibrational spectrum (second-order nonlinear susceptibility) at the vapor/water interface for the first time. The surface orientational structure of the QM water molecules is consistent with the previous MD studies, and the calculated susceptibility reproduces the experimentally reported one, supporting the previous results using the classical force field MD simulation. The present QM/MM MD simulation also demonstrates that the positive sign of the imaginary part of the second-order nonlinear susceptibility at the lower hydrogen bonding OH frequency region originates not from individual molecular orientational structure, but from cooperative electronic structure through the hydrogen bonding network.

  9. Molecular mechanisms of HIV-1 associated neurodegeneration

    Indian Academy of Sciences (India)

    Hakan Ozdener

    2005-06-01

    Since identification of the human immunodeficiency virus-1 (HIV-1), numerous studies suggest a link between neurological impairments, in particular dementia, with acquired immunodeficiency syndrome (AIDS) with alarming occurrence worldwide. Approximately, 60% of HIV-infected people show some form of neurological impairment, and neuropathological changes are found in 90% of autopsied cases. Approximately 30% of untreated HIV-infected persons may develop dementia. The mechanisms behind these pathological changes are still not understood. Mounting data obtained by in vivo and in vitro experiments suggest that neuronal apoptosis is a major feature of HIV associated dementia (HAD), which can occur in the absence of direct infection of neurons. The major pathway of neuronal apoptosis occurs indirectly through release of neurotoxins by activated cells in the central nervous system (CNS) involving the induction of excitotoxicity and oxidative stress. In addition a direct mechanism induced by viral proteins in the pathogenesis of HAD may also play a role. This review focuses on the molecular mechanisms of HIV-associated dementia and possible therapeutic strategies.

  10. 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.

  11. Expression, clinical significance and mechanism of Slit2 in papillary thyroid cancer.

    Science.gov (United States)

    Shi, Rong-Liang; Qu, Ning; Liao, Tian; Wang, Yu-Long; Wang, Yu; Sun, Guo-Hua; Ji, Qing-Hai

    2016-05-01

    Thyroid cancer is a common endocrine malignancy. The last decade has seen exciting progress in understanding thyroid cancer molecular pathogenesis. Several major signaling pathways and related molecular derangements have been elucidated, which represent novel diagnostic and prognostic molecular markers for thyroid cancer. Based on the molecular biology of thyroid cancer, a series of therapeutic targets have been developed, which provide unprecedented opportunities. Thus, histological characterization of subgroups of patients and the correct molecular characterization of patients are thought to be key aspects for future clinical management of these patients. In the present study, we identified Slit2 as a prognostic marker for thyroid cancer oncogenesis and recurrence. Mechanistically, Slit2 regulated Warburg effect in thyroid cancer cells through regulation of HIF1α and HIF1α transcriptional activity. Taken together, our present data uncovered Slit2 as a novel predictive marker for thyroid cancer. The mechanism study indicated that Slit2 regulated the Warburg effect. Additional study on the function of Slit2 in thyroid cancer is required to provide new insights into the potential mechanisms of oncogenesis and recurrence potential of thyroid cancer.

  12. Mechanisms by which circadian rhythm disruption may lead to cancer

    Directory of Open Access Journals (Sweden)

    L. C. Roden

    2010-02-01

    Full Text Available Humans have evolved in a rhythmic environment and display daily (circadian rhythms in physiology, metabolism and behaviour that are in synchrony with the solar day. Modern lifestyles have compromised the exposure to bright light during the day and dark nights, resulting in the desynchronisation of endogenously generated circadian rhythms from the external environment and loss of coordination between rhythms within the body. This has detrimental effects on physical and mental health, due to the misregulation and uncoupling of important cellular and physiological processes. Long-term shift workers who are exposed to bright light at night experience the greatest disruption of their circadian rhythms. Studies have shown an association between exposure to light at night, circadian rhythm disruption and an increased risk of cancer. Previous reviews have explored the relevance of light and melatonin in cancer, but here we explore the correlation of circadian rhythm disruption and cancer in terms of molecular mechanisms affecting circadian gene expression and melatonin secretion.

  13. Molecular mechanisms involved in intestinal iron absorption

    Institute of Scientific and Technical Information of China (English)

    Paul Sharp; Surjit Kaila Srai

    2007-01-01

    Iron is an essential trace metal in the human diet due to its obligate role in a number of metabolic processes.In the diet, iron is present in a number of different forms, generally described as haem (from haemoglobin and myoglobin in animal tissue) and non-haem iron (including ferric oxides and salts, ferritin and lactoferrin).This review describes the molecular mechanisms that co-ordinate the absorption of iron from the diet and its release into the circulation. While many components of the iron transport pathway have been elucidated, a number of key issues still remain to be resolved. Future work in this area will provide a clearer picture regarding the transcellular flux of iron and its regulation by dietary and humoral factors.

  14. Molecular mechanism of TNF signaling and beyond

    Institute of Scientific and Technical Information of China (English)

    Zheng-gang LIU

    2005-01-01

    Tumor necrosis factor (TNF) is a proinflammatory cytokine that plays a critical role in diverse cellular events,including cell proliferation, differentiation and apoptosis. TNF is also involved in many types of diseases. In recent years, the molecular mechanisms of TNF functions have been intensively investigated. Studies from many laboratories have demonstrated that the TNF-mediated diverse biological responses are achieved through activating multiple signaling pathways. Especially the activation of transcription factors NF-κB and AP-1 plays a critical role in mediating these cellular responses. Several proteins, including FADD, the death domain kinase RIP and the TNF receptor associated factor TRAF2 have been identified as the key effectors of TNF signaling. Recently, we found that the effector molecules of TNF signaling, such as RIP and TRAF2, are also involved in other cellular responses. These finding suggests that RIP and TRAF2 serve a broader role than as just an effector of TNF signaling.

  15. Molecular Mechanisms of Neonatal Brain Injury

    Directory of Open Access Journals (Sweden)

    Claire Thornton

    2012-01-01

    Full Text Available Fetal/neonatal brain injury is an important cause of neurological disability. Hypoxia-ischemia and excitotoxicity are considered important insults, and, in spite of their acute nature, brain injury develops over a protracted time period during the primary, secondary, and tertiary phases. The concept that most of the injury develops with a delay after the insult makes it possible to provide effective neuroprotective treatment after the insult. Indeed, hypothermia applied within 6 hours after birth in neonatal encephalopathy reduces neurological disability in clinical trials. In order to develop the next generation of treatment, we need to know more about the pathophysiological mechanism during the secondary and tertiary phases of injury. We review some of the critical molecular events related to mitochondrial dysfunction and apoptosis during the secondary phase and report some recent evidence that intervention may be feasible also days-weeks after the insult.

  16. Phenotypic plasticity: molecular mechanisms and adaptive significance.

    Science.gov (United States)

    Kelly, Scott A; Panhuis, Tami M; Stoehr, Andrew M

    2012-04-01

    Phenotypic plasticity can be broadly defined as the ability of one genotype to produce more than one phenotype when exposed to different environments, as the modification of developmental events by the environment, or as the ability of an individual organism to alter its phenotype in response to changes in environmental conditions. Not surprisingly, the study of phenotypic plasticity is innately interdisciplinary and encompasses aspects of behavior, development, ecology, evolution, genetics, genomics, and multiple physiological systems at various levels of biological organization. From an ecological and evolutionary perspective, phenotypic plasticity may be a powerful means of adaptation and dramatic examples of phenotypic plasticity include predator avoidance, insect wing polymorphisms, the timing of metamorphosis in amphibians, osmoregulation in fishes, and alternative reproductive tactics in male vertebrates. From a human health perspective, documented examples of plasticity most commonly include the results of exercise, training, and/or dieting on human morphology and physiology. Regardless of the discipline, phenotypic plasticity has increasingly become the target of a plethora of investigations with the methodological approaches utilized ranging from the molecular to whole organsimal. In this article, we provide a brief historical outlook on phenotypic plasticity; examine its potential adaptive significance; emphasize recent molecular approaches that provide novel insight into underlying mechanisms, and highlight examples in fishes and insects. Finally, we highlight examples of phenotypic plasticity from a human health perspective and underscore the use of mouse models as a powerful tool in understanding the genetic architecture of phenotypic plasticity.

  17. Exact and Optimal Quantum Mechanics/Molecular Mechanics Boundaries.

    Science.gov (United States)

    Sun, Qiming; Chan, Garnet Kin-Lic

    2014-09-09

    Motivated by recent work in density matrix embedding theory, we define exact link orbitals that capture all quantum mechanical (QM) effects across arbitrary quantum mechanics/molecular mechanics (QM/MM) boundaries. Exact link orbitals are rigorously defined from the full QM solution, and their number is equal to the number of orbitals in the primary QM region. Truncating the exact set yields a smaller set of link orbitals optimal with respect to reproducing the primary region density matrix. We use the optimal link orbitals to obtain insight into the limits of QM/MM boundary treatments. We further analyze the popular general hybrid orbital (GHO) QM/MM boundary across a test suite of molecules. We find that GHOs are often good proxies for the most important optimal link orbital, although there is little detailed correlation between the detailed GHO composition and optimal link orbital valence weights. The optimal theory shows that anions and cations cannot be described by a single link orbital. However, expanding to include the second most important optimal link orbital in the boundary recovers an accurate description. The second optimal link orbital takes the chemically intuitive form of a donor or acceptor orbital for charge redistribution, suggesting that optimal link orbitals can be used as interpretative tools for electron transfer. We further find that two optimal link orbitals are also sufficient for boundaries that cut across double bonds. Finally, we suggest how to construct "approximately" optimal link orbitals for practical QM/MM calculations.

  18. An immunosurveillance mechanism controls cancer cell ploidy.

    Science.gov (United States)

    Senovilla, Laura; Vitale, Ilio; Martins, Isabelle; Tailler, Maximilien; Pailleret, Claire; Michaud, Mickaël; Galluzzi, Lorenzo; Adjemian, Sandy; Kepp, Oliver; Niso-Santano, Mireia; Shen, Shensi; Mariño, Guillermo; Criollo, Alfredo; Boilève, Alice; Job, Bastien; Ladoire, Sylvain; Ghiringhelli, François; Sistigu, Antonella; Yamazaki, Takahiro; Rello-Varona, Santiago; Locher, Clara; Poirier-Colame, Vichnou; Talbot, Monique; Valent, Alexander; Berardinelli, Francesco; Antoccia, Antonio; Ciccosanti, Fabiola; Fimia, Gian Maria; Piacentini, Mauro; Fueyo, Antonio; Messina, Nicole L; Li, Ming; Chan, Christopher J; Sigl, Verena; Pourcher, Guillaume; Ruckenstuhl, Christoph; Carmona-Gutierrez, Didac; Lazar, Vladimir; Penninger, Josef M; Madeo, Frank; López-Otín, Carlos; Smyth, Mark J; Zitvogel, Laurence; Castedo, Maria; Kroemer, Guido

    2012-09-28

    Cancer cells accommodate multiple genetic and epigenetic alterations that initially activate intrinsic (cell-autonomous) and extrinsic (immune-mediated) oncosuppressive mechanisms. Only once these barriers to oncogenesis have been overcome can malignant growth proceed unrestrained. Tetraploidization can contribute to oncogenesis because hyperploid cells are genomically unstable. We report that hyperploid cancer cells become immunogenic because of a constitutive endoplasmic reticulum stress response resulting in the aberrant cell surface exposure of calreticulin. Hyperploid, calreticulin-exposing cancer cells readily proliferated in immunodeficient mice and conserved their increased DNA content. In contrast, hyperploid cells injected into immunocompetent mice generated tumors only after a delay, and such tumors exhibited reduced DNA content, endoplasmic reticulum stress, and calreticulin exposure. Our results unveil an immunosurveillance system that imposes immunoselection against hyperploidy in carcinogen- and oncogene-induced cancers.

  19. Molecular targets of selenium in prostate cancer prevention (Review).

    Science.gov (United States)

    Abdulah, Rizky; Kobayashi, Kenji; Yamazaki, Chiho; Koyama, Hiroshi

    2011-08-01

    Prostate cancer is one of the leading causes of cancer-related deaths among males. Although use of the micro-nutrient selenium in prostate cancer clinical trials is limited, the outcomes indicate that selenium is a promising treatment. Furthermore, selenium inhibits prostate cancer through multiple mechanisms, and it is beneficial in controlling the development of this disease. This review highlights the latest epidemiological and biomolecular research on selenium in prostate cancer, as well as its prospects for future clinical use.

  20. 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.

  1. Castration-Resistant Prostate Cancer: Mechanisms, Targets, and Treatment

    Directory of Open Access Journals (Sweden)

    Teresa Maria Santos Amaral

    2012-01-01

    Full Text Available Patients with castration-resistant prostate cancer (CRPC, who progress after docetaxel therapy, had until very recently, only a few therapeutic options. Recent advances in this field brought about new perspectives in the treatment of this disease. Molecular, basic, and translational research has given us a better understanding on the mechanisms of CRPC. This great investment has turned into a more rational approach to the development of new drugs. Some of the new treatments are already available to our patients outside clinical trials and may include inhibitors of androgen biosynthesis; new chemotherapy agents; bone-targeted therapy; and immunotherapy. This paper aims to review the mechanisms of prostate cancer resistance, possible therapeutic targets, as well as new options to treat CRPC.

  2. Novel Insights into the Molecular Mechanisms Governing Mdm2 Ubiquitination and Destruction

    OpenAIRE

    Fukushima, Hidefumi; Inuzuka, Hiroyuki; Shaik, Shavali; Wei, Wenyi

    2010-01-01

    The Mdm2/p53 pathway is compromised in more than 50% of all human cancers, therefore it is an intensive area of research to understand the upstream regulatory pathways governing Mdm2/p53 activity. Mdm2 is frequently overexpressed in human cancers while the molecular mechanisms underlying the timely destruction of Mdm2 remain unclear. We recently reported that Casein Kinase I phosphorylates Mdm2 at multiple sites to trigger Mdm2 interaction with, and subsequent ubiquitination and destruction b...

  3. Drug-DNA intercalation: from discovery to the molecular mechanism.

    Science.gov (United States)

    Mukherjee, Arnab; Sasikala, Wilbee D

    2013-01-01

    The ability of small molecules to perturb the natural structure and dynamics of nucleic acids is intriguing and has potential applications in cancer therapeutics. Intercalation is a special binding mode where the planar aromatic moiety of a small molecule is inserted between a pair of base pairs, causing structural changes in the DNA and leading to its functional arrest. Enormous progress has been made to understand the nature of the intercalation process since its idealistic conception five decades ago. However, the biological functions were detected even earlier. In this review, we focus mainly on the acridine and anthracycline types of drugs and provide a brief overview of the development in the field through various experimental methods that led to our present understanding of the subject. Subsequently, we discuss the molecular mechanism of the intercalation process, free-energy landscapes, and kinetics that was revealed recently through detailed and rigorous computational studies.

  4. Anti-cancer chalcones: Structural and molecular target perspectives.

    Science.gov (United States)

    Mahapatra, Debarshi Kar; Bharti, Sanjay Kumar; Asati, Vivek

    2015-06-15

    Chalcone or (E)-1,3-diphenyl-2-propene-1-one scaffold remained a fascination among researchers in the 21st century due to its simple chemistry, ease of synthesis and a wide variety of promising biological activities. Several natural and (semi) synthetic chalcones have shown anti-cancer activity due to their inhibitory potential against various targets namely ABCG2/P-gp/BCRP, 5α-reductase, aromatase, 17-β-hydroxysteroid dehydrogenase, HDAC/Situin-1, proteasome, VEGF, VEGFR-2 kinase, MMP-2/9, JAK/STAT signaling pathways, CDC25B, tubulin, cathepsin-K, topoisomerase-II, Wnt, NF-κB, B-Raf and mTOR etc. In this review, a comprehensive study on molecular targets/pathways involved in carcinogenesis, mechanism of actions (MOAs), structure activity relationships (SARs) and patents granted have been highlighted. With the knowledge of molecular targets, structural insights and SARs, this review may be helpful for (medicinal) chemists to design more potent, safe, selective and cost effective anti-cancer chalcones.

  5. 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.

  6. Quantum mechanics/molecular mechanics restrained electrostatic potential fitting.

    Science.gov (United States)

    Burger, Steven K; Schofield, Jeremy; Ayers, Paul W

    2013-12-05

    We present a quantum mechanics/molecular mechanics (QM/MM) method to evaluate the partial charges of amino acid residues for use in MM potentials based on their protein environment. For each residue of interest, the nearby residues are included in the QM system while the rest of the protein is treated at the MM level of theory. After a short structural optimization, the partial charges of the central residue are fit to the electrostatic potential using the restrained electrostatic potential (RESP) method. The resulting charges and electrostatic potential account for the individual environment of the residue, although they lack the transferable nature of library partial charges. To evaluate the quality of the QM/MM RESP charges, thermodynamic integration is used to measure the pKa shift of the aspartic acid residues in three different proteins, turkey egg lysozyme, beta-cryptogein, and Thioredoxin. Compared to the AMBER ff99SB library values, the QM/MM RESP charges show better agreement between the calculated and experimental pK(a) values for almost all of the residues considered.

  7. 益生菌抗结肠癌作用及分子机制研究进展%Research Progress of Probiotics in Colon Cancer Prevention and Its Molecular Mechanism

    Institute of Scientific and Technical Information of China (English)

    李冰; 单毓娟; 张兰威; 张英春; 陈镜羽

    2013-01-01

    Probiotics are usually live microorganisms which confer health benefits on host like improving intestinal flora balance. It can improve a number of physiological functions such as enhancing immunity, relieving hypersensitivity and inflammatory bowel disease, defencing infection, as well as anticancer, etc. This review summary the research progress of anti-colon-cancer effectiveness of probiotics, its fermentation broth, its bacteria composition and metabolic compositions firstly. Then the molecular mechanisms of its anti-colon carcinoma properties are introduced. Its molecular mechanisms mainly includes: immune-modulatory properties and anti-inflammatory, inhibiting proliferation and promoting apoptosis, producing beneficial metabolites, inhibiting carcinogens-activated enzyme and an-ti-genotoxic activity. Finally, the applications of probiotics in clinic are presented. The results show that probiotics not only play a protective role in the development of colon cancer, but also greatly improve the gut symptoms of patients with carcinoma after colostomy. At present, separation of active probiotic bacteria ingredients and its function research has become a research focus. These will provide the novel strategies and idea for exploring , exploiting and applying the products of probiotics in future.%益生菌是指一类通过改善肠内菌群平衡,对宿主起到有益作用的活性微生物,具有提高免疫力、抗过敏、缓解炎性肠道疾病、抗感染、抗癌等生物学功能.本文首先阐述益生菌、益生菌发酵液、其菌体成分、代谢成分抗结肠癌作用的研究进展;随后阐述其抗结肠癌的分子机制,主要包括;免疫调节和抗炎症作用,抑制细胞增殖和促进细胞凋亡,产生有益的代谢物和抑制致癌物活化酶与遗传解毒;最后介绍益生菌在临床医学研究中的应用情况,益生菌不仅可以在结肠癌发生过程中起到一定的保护作用,且能够很好的改善结肠

  8. Multiresolution molecular mechanics: Implementation and efficiency

    Science.gov (United States)

    Biyikli, Emre; To, Albert C.

    2017-01-01

    Atomistic/continuum coupling methods combine accurate atomistic methods and efficient continuum methods to simulate the behavior of highly ordered crystalline systems. Coupled methods utilize the advantages of both approaches to simulate systems at a lower computational cost, while retaining the accuracy associated with atomistic methods. Many concurrent atomistic/continuum coupling methods have been proposed in the past; however, their true computational efficiency has not been demonstrated. The present work presents an efficient implementation of a concurrent coupling method called the Multiresolution Molecular Mechanics (MMM) for serial, parallel, and adaptive analysis. First, we present the features of the software implemented along with the associated technologies. The scalability of the software implementation is demonstrated, and the competing effects of multiscale modeling and parallelization are discussed. Then, the algorithms contributing to the efficiency of the software are presented. These include algorithms for eliminating latent ghost atoms from calculations and measurement-based dynamic balancing of parallel workload. The efficiency improvements made by these algorithms are demonstrated by benchmark tests. The efficiency of the software is found to be on par with LAMMPS, a state-of-the-art Molecular Dynamics (MD) simulation code, when performing full atomistic simulations. Speed-up of the MMM method is shown to be directly proportional to the reduction of the number of the atoms visited in force computation. Finally, an adaptive MMM analysis on a nanoindentation problem, containing over a million atoms, is performed, yielding an improvement of 6.3-8.5 times in efficiency, over the full atomistic MD method. For the first time, the efficiency of a concurrent atomistic/continuum coupling method is comprehensively investigated and demonstrated.

  9. Novel Tissue‐Specific Mechanism of Regulation of Angiogenesis and Cancer Growth in Response to Hyperglycemia

    OpenAIRE

    Bhattacharyya, Sanghamitra; Sul, Kristina; Krukovets, Irene; Nestor, Carla; Li, Jianbo; Adognravi, Olga Stenina

    2012-01-01

    Background Hyperglycemia is an independent risk factor for the development of vascular diabetic complications, which are characterized by endothelial dysfunction and tissue‐specific aberrant angiogenesis. Tumor growth is also dependent on angiogenesis. Diabetes affects several cancers in a tissue‐specific way. For example, it positively correlates with the incidence of breast cancer but negatively correlates with the incidence of prostate cancer. The tissue‐specific molecular mechanisms activ...

  10. The current state of molecular cytogenetics in cancer diagnosis.

    Science.gov (United States)

    Liehr, Thomas; Othman, Moneeb A K; Rittscher, Katharina; Alhourani, Eyad

    2015-04-01

    Cytogenetics and molecular cytogenetics are and will continue to be indispensable tools in cancer diagnostics. Leukemia and lymphoma diagnostics are still emphases of routine (molecular) cytogenetics and corresponding studies of solid tumors gain more and more prominence. Here, first a historical perspective of molecular tumor cytogenetics is provided, which is followed by the basic principles of the fluorescence in situ hybridization (FISH) approach. Finally the current state of molecular cytogenetics in cancer diagnostics is discussed. Nowadays routine diagnostics includes basic FISH approaches rather than multicolor-FISH. The latter together with modern high-throughput methods have their impact on research to identify new tumor-associated genomic regions.

  11. Molecular Mechanisms of Prostate Cancer Progression

    Science.gov (United States)

    2005-01-01

    Government Member, Texas A&M University, College Station, TX 1988-1989 Dean’s List, The Colorado College, Colorado Springs, CO 1988 Most Dedicated Football ...was digested using six restriction enzymes Alu I, Msp I, Rsa I, Cfo I, Hae III, and Hinf I (Gibco-BRL) for 2 hours at 37°C. A telomere-specific probe

  12. Molecular Mechanisms of Breast Cancer Metastasis

    Science.gov (United States)

    2005-05-01

    sites. Genetica 117, 135-147. Society of America, Pittsburgh, PA, p. 231B. Festenstein, R., Sharghi-Namini, S., Fox, M., Roderick, K., Tolaini, M...V. and Vagin, V. V. Genetica , 2003, 117, 239. 86. Aravin, A. A., Klenov, M. S., Vagin, V. V., Bantignies, F., Cavalli, G. and Gvozdev, V. A. Mol Cell

  13. Breast cancer prevention: lessons to be learned from mechanisms of early pregnancy-mediated breast cancer protection.

    Science.gov (United States)

    Meier-Abt, Fabienne; Bentires-Alj, Mohamed; Rochlitz, Christoph

    2015-03-01

    Pregnancy at early, but not late age, has a strong and life-long protective effect against breast cancer. The expected overall increase in breast cancer incidence demands the development of a pharmaceutical mimicry of early-age pregnancy-mediated protection. Recently, converging results from rodent models and women on molecular and cellular mechanisms underlying the protective effect of early-age pregnancy have opened the door for translational studies on pharmacologic prevention against breast cancer. In particular, alterations in Wnt and TGFβ signaling in mammary stem/progenitor cells reveal new potential targets for preventive interventions, and thus might help to significantly reduce the incidence of breast cancer in the future.

  14. Molecular cytogenetics: recent developments and applications in cancer.

    Science.gov (United States)

    Das, K; Tan, P

    2013-10-01

    Aneuploidy or alteration in chromosome numbers is a characteristic feature in cancer that is generally a consequence of defective chromosome segregation during cell division. Molecular cytogenetic analyses have conferred substantial evidence with regards to the chromosomal architectures in cancer. Most importantly, the fluorescence in situ hybridization (FISH) technique that plays a leading role in diagnostic pathology for its single-cell analysis has provided crucial information regarding genomic variations in malignant cells. Further development of molecular cytogenetic methodologies such as chromosome specific FISH karyotyping and comparative genomic hybridization have also helped in the detection of cryptic genetic changes in cancer. But, the recent advancement of high throughput sequencing technologies have provided a more comprehensive genomic analyses resulting in novel chromosome rearrangements, somatic mutations as well as identification of fusion genes leading to new therapeutic targets. This review highlights the application of early molecular cytogenetics and the recent high throughput genomic approaches in characterizing various cancers and their invaluable support in cancer therapeutics.

  15. Molecular Imaging of Breast Cancer: Role of RGD Peptides.

    Science.gov (United States)

    Chakravarty, Rubel; Chakraborty, Sudipta; Dash, Ashutosh

    2015-01-01

    Breast cancer is the leading cause of cancer deaths among women of all ages worldwide. With advances in molecular imaging procedures, it has been possible to detect breast cancer in its early stage, determine the extent of the disease to administer appropriate therapeutic protocol and also monitor the effects of treatment. By accurately characterizing the tumor properties and biological processes involved, molecular imaging can play a crucial role in minimizing the morbidity and mortality associated with breast cancer. The integrin αvβ3 plays an important role in breast cancer angiogenesis and is expressed on tumor endothelial cells as well as on some tumor cells. It is a receptor for the extracellular matrix proteins with the exposed arginine-glycine-aspartic acid (RGD) tripeptide sequence and therefore RGD peptides can preferentially bind to integrin αvβ3. In this context, targeting tumor vasculature or tumor cells by RGD-based probes is a promising strategy for molecular imaging of breast cancer. Using RGD-based probes, several preclinical studies have employed different imaging modalities such as positron emission tomography (PET), single photon emission computed tomography (SPECT), magnetic resonance imaging (MRI), ultrasound and optical imaging for visualization of integrin αvβ3 expression in breast cancer models. Limited clinical trials using (18)F-labeled RGD peptides have also been initiated for non-invasive detection and staging of breast cancer. Herein, we provide a comprehensive overview of the latest advances in molecular imaging of breast cancer using RGD peptide-based probes and discuss the challenges and opportunities for advancement of the field. The reported strategies for molecular imaging of breast cancer using RGD peptide-based probes holds promise for making clinically translatable advances that can positively impact the overall diagnostic and therapeutic processes and result in improved quality of life for breast cancer patients.

  16. Basic evidence of molecular targeted therapy for oral cancer and salivary gland cancer.

    NARCIS (Netherlands)

    Hamakawa, H.; Nakashiro, K.; Sumida, T.; Shintani, S.; Myers, J.N.; Takes, R.P.; Rinaldo, A.; Ferlito, A.

    2008-01-01

    BACKGROUND: Recently, attention has been focused on molecular targeted cancer therapy in various tumors. Although there is no single consistent molecular target specific for oral squamous cell carcinoma (OSCC) and salivary gland cancer (SGC), there are a number of promising candidate proteins. The a

  17. Population pharmacokinetics and pharmacodynamics of paclitaxel and carboplatin in ovarian cancer patients : A study by the European Organization for Research and Treatment of Cancer-Pharmacology and Molecular Mechanisms Group and New Drug Development Group

    NARCIS (Netherlands)

    Joerger, Markus; Huitema, Alwin D. R.; Richel, Dick J.; Dittrich, Christian; Pavlidis, Nikolas; Briasoulis, Evangelos; Vermorken, Jan B.; Strocchi, Elena; Martoni, Andrea; Sorio, Roberto; Sleeboom, Henk P.; Izquierdo, Miguel A.; Jodrell, Duncan I.; Calvert, Hilary; Boddy, Alan V.; Hollema, Harry; Fety, Regine; Van der Vijgh, Wjf J. F.; Hempel, Georg; Chatelut, Etienne; Karlsson, Mats; Wilkins, Justin; Tranchand, Brigitte; Schrijvers, Ad H. G. J.; Twelves, Christian; Beijnen, Jos H.; Schellens, Jan H. M.

    2007-01-01

    Purpose: Paclitaxel and carboplatin are frequently used in advanced ovarian cancer following cytoreductive surgery. Threshold models have been used to predict paclitaxel pharmacokinetic-pharmacodynamics, whereas the time above paclitaxel plasma concentration of 0.05 to 0.2 mu mol/L (t(c > 0.05-0.2))

  18. Function and molecular mechanism of protease inhibitor MG132 in cancer cachexia%蛋白酶体抑制剂MG132对肿瘤恶病质的作用及其分子机制

    Institute of Scientific and Technical Information of China (English)

    张刘平; 唐华; 寇耀; 郑曰勇; 陈志雄; 安昌勇

    2013-01-01

    Objective To investigate the function and possible molecular mechanism of protease inhibitor MG132 in cancer cachexia. Methods Twenty-four male BALB/c mice were divided into healthy control (HC), cancer cachexia (CC) and MG132 treatment (MG) groups. The mice in HC group were uninjected, while those in CC and MG groups were injected s.c. with colon adenocarcinoma C26 cells to establish the mouse model of cancer cachexia. The model mice in MG group were injected i.p. with 0. 1 mg/kg MG132, while those in CC group with 0. 1 ml physiological saline. The mice in various groups were killed 7 d after treatment, of which the tumor, left gastrocnemius muscle and epididymis adipose tissue were weighed, the fiber crosscut area of gastrocnemius muscle was measured, the TNF-a and IL-6 levels in sera were determined by ELISA, while the mRNA transcription and protein expression levels of IkBa, P65, MuRF1 and MAFbx were determined by RT-PCR and Western blot respectively. Results Compared with those in CC group, the weights of gastrocnemius muscle and epididymis adipose tissue of mice in MG group increased by 31. 6% and 39. 5% respectively(P < 0. 05), the fiber crosscut area of gastrocnemius muscle increased by 36. 1% (P < 0. 05), while the TNF-a and IL-6 levels in sera decreased by 20. 9% and 42. 0% respectively (P < 0. 05); however, the mRNA transcription and protein expression levels of IKBa in gastrocnemius muscle increased by 132. 7% and 56. 5% respectively (P < 0. 05), while those of MuRFl decreased by 70. 1% and 42. 6%(P < 0. 05), those of MAFbx decreased by 76. 8% and 47. 3% (P < 0. 05), and those of P65 decreased by 59. 1% and 53. 1%, respectively (P < 0. 05). Conclusion The molecular mechanism of MG132 in improving cancer cachexia may be related to the inhibitions of NF-KB pathway, MuRFl and MAFbx expressions, inflammatory reaction and tumor growth.%目的 探讨蛋白酶体抑制剂MG132对肿瘤恶病质的作用及其可能的分子机制.方法 经小

  19. 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

  20. Survivin-T34A: molecular mechanism and therapeutic potential

    Directory of Open Access Journals (Sweden)

    Jonathan R Aspe

    2010-12-01

    Full Text Available Jonathan R Aspe, Nathan R WallCenter for Health Disparities Research and Molecular Medicine, Division of Biochemistry and Microbiology, Department of Basic Sciences, Loma Linda University, Loma Linda, CA, USAAbstract: The inhibitor of apoptosis protein survivin's threonine 34 to alanine (T34A mutation abolishes a phosphorylation site for p34(cdc2–cyclin B1, resulting in initiation of the mitochondrial apoptotic pathway in cancer cells; however, it has little known direct effects on normal cells. The possibility that targeting survivin in this way may provide a novel approach for selective cancer gene therapy has yet to be fully evaluated. Although a flurry of work was undertaken in the late 1990s and early 2000s, only minor advances on this mutant have recently taken place. We recently described that cells generated to express a stable form of the mutant protein released this survivin-T34A to the conditioned medium. When this conditioned medium was collected and deposited on naive tumor cells, conditioned medium T34A was as effective as some chemotherapeutics in the induction of tumor cell apoptosis, and when combined with other forms of genotoxic stressors potentiated their killing effects. We hope with this review to revitalize the T34A field, as there is still much that needs to be investigated. In addition to determining the therapeutic dose and the duration of drug therapy required at the disease site, a better understanding of other key factors is also important. These include knowledge of target cell populations, cell-surface receptors, changes that occur in the target tissue at the molecular and cellular level with progression of the disease, and the mechanism and site of therapeutic action.Keywords: survivin, T34A, apoptosis, proliferation, therapy

  1. Silica Synthesis by Sponges: Unanticipated Molecular Mechanism

    Science.gov (United States)

    Morse, D. E.; Weaver, J. C.

    2001-12-01

    substitutions of specific amino acid sidechains, in conjunction with computer-assisted molecular modeling and biomimetic synthesis, allowed us to probe the determinants of catalytic activity and confirm the identification of the amino acid sidechains required for hydrolysis of the silicon alkoxides. If, as suggested by the data of others, silicic acid is conjugated with organic moieties after its transport into the cell, the catalytic mechanism described here may be important in biosilicification by sponges. As is often the case, we have been better able to answer mechanistic questions about "how" silica can be formed biologically, than "why" the diversity of structures is elaborated. Studies of spicule formation during cellular regeneration in Tethya aurantia reveal that synthesis of the larger silica needles (megascleres) and smaller starburst-shaped microscleres may be independently regulated, presumably at the genetic level. The spatial segregation of these morphologically-distinct spicule types within the sponge further suggests an adaptive significance of the different skeletal elements.

  2. New generation of breast cancer clinical trials implementing molecular profiling

    Institute of Scientific and Technical Information of China (English)

    Dimitrios Zardavas; Martine Piccart-Gebhart

    2016-01-01

    The implementation of molecular profiling technologies in oncology deepens our knowledge for the molecular landscapes of cancer diagnoses, identifying aberrations that could be linked with specific therapeutic vulnerabilities. In particular, there is an increasing list of molecularly targeted anticancer agents undergoing clinical development that aim to block specific molecular aberrations. This leads to a paradigm shift, with an increasing list of specific aberrations dictating the treatment of patients with cancer. This paradigm shift impacts the field of clinical trials, since the classical approach of having clinico-pathological disease characteristics dictating the patients' enrolment in oncology trials shifts towards the implementation of molecular profiling as pre-screening step. In order to facilitate the successful clinical development of these new anticancer drugs within specific molecular niches of cancer diagnoses, there have been developed new, innovative trial designs that could be classified as follows: i) longitudinal cohort studies that implement (or not) "nested" downstream trials, 2) studies that assess the clinical utility of molecular profiling, 3) "master" protocol trials, iv) "basket" trials, v) trials following an adaptive design. In the present article, we review these innovative study designs, providing representative examples from each category and we discuss the challenges that still need to be addressed in this era of new generation oncology trials implementing molecular profiling. Emphasis is put on the field of breast cancer clinical trials.

  3. Molecular mechanisms of cholangiocarcinoma cell inhibition by medicinal plants

    Science.gov (United States)

    Leelawat, Surang; Leelawat, Kawin

    2017-01-01

    Cholangiocarcinoma (CCA) is one of the most common causes of cancer-associated mortality in Thailand. Certain phytochemicals have been demonstrated to modulate apoptotic signaling pathways, which may be targeted for the prevention and treatment of cancer. Therefore, the aim of the present study was to investigate the effect of specific medicinal plants on the inhibition of CCA cell proliferation, and to identify the molecular mechanisms underlying this. A WST-1 cell proliferation assay was performed using an RMCCA1 cell line, and apoptotic signaling pathways were also investigated using a PathScan Stress and Apoptosis Signaling Antibody Array Kit. The cell proliferation assay indicated that extracts from the Phyllanthus emblica fruit pulp (PEf), Phyllanthus emblica seed (PEs), Terminalia chebula fruit pulp (TCf), Terminalia chebula seed (TCs), Areca catechu seed (ACs), Curcuma longa (CL) and Moringa oleifera seed (MOs) exerted anti-proliferative activity in RMCCA1 cells. In addition, the PathScan assay revealed that certain pro-apoptotic molecules, including caspase-3, poly (ADP-ribose) polymerase, checkpoint kinase 2 and tumor protein 53, exhibited increased activity in RMCCA1 cells treated with the aforementioned selected plant extracts, with the exception of PEf. The mitogen-activated protein kinase (MAPK) pathways (including ERK1/2 and p38 MAPK) expression level was significantly increased in RMCCA1 cells pre-treated with extracts of PEs, TCf, CL and MOs. The activation of protein kinase B (Akt) was significantly demonstrated in RMCCA1 cells pre-treated with extracts of TCf, ACs and MOs. In summary, the present study demonstrated that extracts of PEs, TCf, TCs, ACs, CL and MOs exhibited anti-proliferative effects in CCA cells by inducing pro-apoptotic signals and modulating signal transduction molecules. Further studies in vivo are required to demonstrate the potential applications of specific plant extracts for the treatment of human cancer.

  4. Mechanisms of multidrug resistance in cancer.

    Science.gov (United States)

    Gillet, Jean-Pierre; Gottesman, Michael M

    2010-01-01

    The development of multidrug resistance (MDR) to chemotherapy remains a major challenge in the treatment of cancer. Resistance exists against every effective anticancer drug and can develop by numerous mechanisms including decreased drug uptake, increased drug efflux, activation of detoxifying systems, activation of DNA repair mechanisms, evasion of drug-induced apoptosis, etc. In the first part of this chapter, we briefly summarize the current knowledge on individual cellular mechanisms responsible for MDR, with a special emphasis on ATP-binding cassette transporters, perhaps the main theme of this textbook. Although extensive work has been done to characterize MDR mechanisms in vitro, the translation of this knowledge to the clinic has not been crowned with success. Therefore, identifying genes and mechanisms critical to the development of MDR in vivo and establishing a reliable method for analyzing clinical samples could help to predict the development of resistance and lead to treatments designed to circumvent it. Our thoughts about translational research needed to achieve significant progress in the understanding of this complex phenomenon are therefore discussed in a third section. The pleotropic response of cancer cells to chemotherapy is summarized in a concluding diagram.

  5. 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.

  6. Novel approaches for the molecular classification of prostate cancer

    Institute of Scientific and Technical Information of China (English)

    Robert H. Getzenberg

    2010-01-01

    @@ Among the urologic cancers, prostate cancer is by far the most common, and it appears to have the potential to affect almost all men throughout the world as they age. A number of studies have shown that many men with prostate cancer will not die from their disease, but rather with the disease but from other causes. These men have a form of prostate cancer that is de-scribed as "very low risk" and has often been called indolent. There are however a group of men that have a form of prostate cancer that is much more aggressive and life threatening. Unlike other cancer types, we have few tools to provide for the molecular classification of prostate cancer.

  7. Ultrasound for molecular imaging and therapy in cancer

    OpenAIRE

    Kaneko, Osamu F; Willmann, Jürgen K.

    2012-01-01

    Over the past decade, molecularly-targeted contrast enhanced ultrasound (ultrasound molecular imaging) has attracted significant attention in preclinical research of cancer diagnostic and therapy. Potential applications for ultrasound molecular imaging run the gamut from early detection and characterization of malignancies to monitoring treatment responses and guiding therapies. There may also be a role for ultrasound contrast agents for improved delivery of chemotherapeutic drugs and gene th...

  8. Molecular Concordance Between Primary Breast Cancer and Matched Metastases

    DEFF Research Database (Denmark)

    Krøigård, Anne Bruun; Larsen, Martin Jakob; Thomassen, Mads;

    2016-01-01

    . The purpose of this review is to illuminate the extent of cancer genome evolution through disease progression and the degree of molecular concordance between primary breast cancers and matched metastases. We present an overview of the most prominent studies investigating the expression of endocrine receptors......Clinical management of breast cancer is increasingly personalized and based on molecular profiling. Often, primary tumors are used as proxies for systemic disease at the time of recurrence. However, recent studies have revealed substantial discordances between primary tumors and metastases, both......, transcriptomics, and genome aberrations in primary tumors and metastases. In conclusion, biopsy of metastatic lesions at recurrence of breast cancer is encouraged to provide optimal treatment of the disease. Furthermore, molecular profiling of metastatic tissue provides invaluable mechanistic insight...

  9. Anatomical and molecular imaging of skin cancer

    OpenAIRE

    Cai, Weibo

    2008-01-01

    Hao Hong1, Jiangtao Sun1, Weibo Cai1,21Departments of Radiology and Medical Physics, School of Medicine and Public Health, University of Wisconsin – Madison, Madison, Wisconsin, USA; 2University of Wisconsin Paul P. Carbone Comprehensive Cancer Center, Madison, Wisconsin, USAAbstract: Skin cancer is the most common form of cancer types. It is generally divided into two categories: melanoma (∼5%) and nonmelanoma (∼95%), which can be further categorized into basal cell...

  10. Statistical mechanics of quasispecies theories of molecular evolution

    Science.gov (United States)

    Munoz Tavera, Enrique

    This thesis presents a statistical mechanical analysis of different formulations of quasispecies theory of molecular evolution. These theories, characterized by two different families of models, the Crow-Kimura and the Eigen model, constitute a microscopie description of evolution. These models are most often used for RNA viruses, where a phase transition is predicted, in agreement with experiments, between an organized or quasispecies phase, and a disordered non-selective phase when the mutation rate exceeds a critical value. The methods of statistical mechanics, in particular field-theoretic methods, are employed to obtain analytic solutions to four problems relevant to biological interest. The first chapter presents the study of evolution under a multiple-peak fitness landscape, with biological applications in the study of the proliferation of viruses or cancer under the control of drugs or the immune system. The second chapter studies the effect of incorporating different forms of horizontal gene transfer and two-parent recombination to the classical formulation of quasispecies models. As an example, we study the effect of the sign of epistasis of the fitness landscape on the advantage or disadvantage of recombination for the mean fitness. The third chapter considers the relaxation of the purine/pyrimidine assumption in the classical formulation of the models, by formulating and solving the parallel and Eigen models in the context of a four-letter alphabet. The fourth and final chapter studies finite population effects, both in the presence and in the absence of horizontal gene transfer.

  11. The molecular mechanism of thalidomide analogs in hematologic malignancies.

    Science.gov (United States)

    Lindner, Stefanie; Krönke, Jan

    2016-12-01

    Thalidomide was sold in the 1950s as a sedative and was also used by pregnant women to treat morning sickness. It became notorious for causing severe birth defects and was removed from the market. More than four decades later, thalidomide had a renaissance in the treatment of cancer. Thalidomide and its more potent analogs, lenalidomide and pomalidomide, are nowadays approved treatments for multiple myeloma and myelodysplastic syndrome with deletion of chromosome 5q. In addition, thalidomide and its analogs inhibit release of tumor necrosis factor-α and increase interleukin-2 (IL-2) and interferon-γ release from T cells. The underlying molecular mechanisms for these pleiotropic effects remained obscure until the identification of the cereblon (CRBN) E3 ubiquitin ligase as the primary target of thalidomide and its analogs in 2010. Binding of thalidomide or lenalidomide increases the affinity of CRBN to the transcription factors IKZF1 and IKZF3 and casein kinase 1α (CK1α). Ubiquitination and degradation of these neo-substrates results in IL-2 release and growth arrest of multiple myeloma and MDS cells. The discovery of this previously undescribed mechanism for an approved drug provides a proof-of-concept for the development of new therapeutics that exploit ubiquitin ligases for specific degradation of disease-associated proteins.

  12. Defective DNA repair mechanisms in prostate cancer: impact of olaparib

    Directory of Open Access Journals (Sweden)

    De Felice F

    2017-03-01

    Full Text Available Francesca De Felice,1 Vincenzo Tombolini,1 Francesco Marampon,2 Angela Musella,3 Claudia Marchetti3 1Department of Radiotherapy, Policlinico Umberto I, “Sapienza” University of Rome, Rome, 2Department of Biotechnological and Applied Clinical Sciences, Laboratory of Radiobiology, University of L’Aquila, L’Aquila, 3Department of Gynecological and Obstetrical Sciences and Urological Sciences, “Sapienza” University of Rome, Rome, Italy Abstract: The field of prostate oncology has continued to change dramatically. It has truly become a field that is intensely linked to molecular genetic alterations, especially DNA-repair defects. Germline breast cancer 1 gene (BRCA1 and breast cancer 2 gene (BRCA2 mutations are implicated in the highest risk of prostate cancer (PC predisposition and aggressiveness. Poly adenosine diphosphate ribose polymerase (PARP proteins play a key role in DNA repair mechanisms and represent a valid target for new therapies. Olaparib is an oral PARP inhibitor that blocks DNA repair pathway and coupled with BRCA mutated-disease results in tumor cell death. In phase II clinical trials, including patients with advanced castration-resistant PC, olaparib seems to be efficacious and well tolerated. Waiting for randomized phase III trials, olaparib should be considered as a promising treatment option for PC. Keywords: prostate cancer, metastatic disease, castration resistant, BRCA, DNA-repair, PARP, olaparib

  13. VEGF and colon cancer growth beyond angiogenesis: does VEGF directly mediate colon cancer growth via a non-angiogenic mechanism?

    Science.gov (United States)

    Ahluwalia, Amrita; Jones, Michael K; Matysiak-Budnik, Tamara; Tarnawski, Andrzej S

    2014-01-01

    In this article we review the role of vascular endothelial growth factor (VEGF) in colon cancer growth and the underlying mechanisms. Angiogenesis, the growth of new capillary blood vessels in the body, is critical for tissue injury healing and cancer growth. In 1971, Judah Folkman proposed the concept that tumor growth beyond 2 mm is critically dependent on angiogenesis. Tumors including colon cancers release angiogenic growth factors that stimulate blood vessels to grow into the tumors thus providing oxygen and nutrients that enable exponential growth. VEGF is the most potent angiogenic growth factor. Several studies have highlighted the role of VEGF in colon cancer, specifically in the stimulation of angiogenesis. This role of VEGF is strongly supported by studies showing that inhibition of VEGF using the blocking antibody, bevacizumab, results in decreased angiogenesis and abrogation of cancer growth. In the United States, bevacizumab in combination with chemotherapy is FDA approved for the treatment of metastatic colon cancer. However, the source of VEGF in colon cancer tissue, the mechanisms of VEGF generation in colon cancer cells and the molecular pathways involved in VEGF mediated angiogenesis in colon cancer are not fully known. The possibility that VEGF directly stimulates cancer cell growth in an autocrine manner has not been explored in depth.

  14. Common mechanisms of onset of cancer and neurodegenerative diseases.

    Science.gov (United States)

    Ariga, Hiroyoshi

    2015-01-01

    Onset of cancer and neurodegenerative disease occurs by abnormal cell growth and neuronal cell death, respectively, and the number of patients with both diseases has been increasing in parallel with an increase in mean lifetime, especially in developed countries. Although both diseases are sporadic, about 10% of the diseases are genetically inherited, and analyses of such familial forms of gene products have contributed to an understanding of the molecular mechanisms underlying the onset and pathogenesis of these diseases. I have been working on c-myc, a protooncogene, for a long time and identified various c-Myc-binding proteins that play roles in c-Myc-derived tumorigenesis. Among these proteins, some proteins have been found to be also responsible for the onset of neurodegenerative diseases, including Parkinson's disease, retinitis pigmentosa and cerebellar atrophy. In this review, I summarize our findings indicating the common mechanisms of onset between cancer and neurodegenerative diseases, with a focus on genes such as DJ-1 and Myc-Modulator 1 (MM-1) and signaling pathways that contribute to the onset and pathogenesis of cancer and neurodegenerative diseases.

  15. Gallic acid: molecular rival of cancer.

    Science.gov (United States)

    Verma, Sharad; Singh, Amit; Mishra, Abha

    2013-05-01

    Gallic acid, a predominant polyphenol, has been shown to inhibit carcinogenesis in animal models and in vitro cancerous cell lines. The inhibitory effect of gallic acid on cancer cell growth is mediated via the modulation of genes which encodes for cell cycle, metastasis, angiogenesis and apoptosis. Gallic acid inhibits activation of NF-κB and Akt signaling pathways along with the activity of COX, ribonucleotide reductase and GSH. Moreover, gallic acid activates ATM kinase signaling pathways to prevent the processes of carcinogenesis. The data so far available, both from in vivo and in vitro studies, indicate that this dietary polyphenol could be promising agent in the field of cancer chemoprevention.

  16. Targets for molecular therapy of skin cancer.

    Science.gov (United States)

    Green, Cheryl L; Khavari, Paul A

    2004-02-01

    Cancers of the skin encompass the first and second most common neoplasms in the United States, epidermal basal cell carcinoma (BCC) and squamous cell carcinoma (SCC), respectively, as well as the melanocytic malignancy, malignant melanoma (MM). Recently identified alterations in the function of specific genes in these cancers provide new potential therapeutic targets. These alterations affect conserved regulators of cellular proliferation and viability, including the Sonic Hedgehog, Ras/Raf, ARF/p53, p16(INK4A)/CDK4/Rb and NF-kappaB pathways. New modalities designed to target these specific proteins may represent promising approaches to therapy of human skin cancers.

  17. [Local immune tolerance mechanisms in kidney cancer].

    Science.gov (United States)

    Patard, Jean-Jacques; Bouet, Françoise; Rioux-Leclercq, Nathalie; Lobel, Bernard; Catros-Quemener, Véronique; Guillé, François

    2002-04-01

    Many arguments suggest that renal tumours are immunogenic. However, the immune cells present around or within the tumour are unable to induce tumour rejection and the results of immunotherapy in metastatic renal cancer remain disappointing regardless of the protocols used. The objective of this study was to review the main mechanisms by which a renal tumour can escape immune destruction. These mechanisms can concern: tumour antigens, antigen-presenting molecules on the cell surface or defects of the cell machinery leading to the preparation of these molecules. Defects may also concern intercellular communications, especially adhesion and co-stimulation molecules. The immune cells present may also be defective, presenting qualitative or quantitative deficits, abnormalities of the T receptor, defect of cytokine production and these defects may concern both effector cells and antigen-presenting cells. The capacity of tumour cells to release anergic substances, i.e. substances which paralyze the immune system, also constitutes another very powerful immunosuppressive mechanism. These substances are cytokines, especially TGF-b. This anergy can also be mediated by intercellular contacts between tumour cells and lymphocytes, especially via the Fas system. It is important to study these mechanisms for several reasons: 1/Understanding of anergy mechanisms in order to discover new therapeutic targets or to short-circuit these mechanisms in vitro; 2/Definition of an "immune phenotype" of the tumour which should be evaluated as a prognostic marker both for survival after radical surgery of localized tumours as a prognostic factor for response to immunotherapy in metastatic forms.

  18. Precursor lesions in pancreatic cancer: morphological and molecular pathology.

    Science.gov (United States)

    Scarlett, Christopher J; Salisbury, Elizabeth L; Biankin, Andrew V; Kench, James

    2011-04-01

    Pancreatic cancer has a dismal prognosis and is the fourth most common cause of cancer related death in Western societies. In large part this is due to its typically late presentation, usually as locally advanced or metastatic disease. Identification of the non-invasive precursor lesions to pancreatic cancer raises the possibility of surgical treatment or chemoprevention at an early stage in the evolution of this disease, when more amenable to therapeutic interventions. Precursor lesions to pancreatic ductal adenocarcinoma, in particular pancreatic intraepithelial neoplasia (PanIN), have been recognised under a variety of synonyms for over 50 years. Over the past decade our understanding of the morphology, biological significance and molecular aberrations of these lesions has grown rapidly and there is now a widely accepted progression model integrating the accumulated morphological and molecular observations. Further progress is likely to be accelerated by improved mouse models of pancreatic cancer and by insight into the cancer genome gained by the International Cancer Genome Consortium (ICGC), in which an Australian consortium is leading the pancreatic cancer initiative. This review also outlines the morphological and molecular features of the other two precursors of pancreatic ductal adenocarcinoma, i.e., intraductal papillary mucinous neoplasms and mucinous cystic neoplasms.

  19. [Matrix metalloproteases as molecular markers in gastric cancer].

    Science.gov (United States)

    de la Peña, Sol; Sampieri, Clara L; León-Córdoba, Kenneth

    2010-02-06

    Gastric cancer is the second leading cause of cancer-associated mortality in the world. Prognosis in patients with gastric cancer is difficult to establish because it is commonly diagnosed when gastric wall invasion and metastasis have occurred. Currently, some members of the extracellular matrix metalloproteinases have been identified, whose expression in gastric tumor tissue is significantly elevated compared to healthy gastric tissue. Matrix metalloproteinases are 24 zinc-dependent endopeptidases that catalyze the proteolysis of the extracellular matrix. This degradation allows the cancer cells invade the surrounding stroma and trigger metastasis. Upregulation of certain matrix metalloproteinases in gastric cancer has been associated with a poor prognosis and elevated invasive capacity. This review compiles evidence about the genetic expression of matrix metalloproteinases in gastric cancer and their role in tumour invasion and metastasis, emphasizing their potential as molecular markers of prognosis.

  20. 2. Molecular Biology as a Tool in Cancer Epidemiology

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@There can be little doubt that we are entering a new era in our understanding of the origins of human cancer. Unfortunately from the point of view of the cancer epidemiology community, some of the more recent advances in the molecular biology of cancer (once fully assimilated) will tend to make the talk of the up-to-date cancer epidemiologist a great deal less straightforward than many of us had previously envisaged it to be, There may still be a few cancers that will prove to result from only a few distinctive types of mutation in a relatively small number of genes, but I strongly suspect that the great majority of human cancers that we wish to study will prove to have their origins in a complex set of DNA changes whose precise

  1. The cognitive life of mechanical molecular models.

    Science.gov (United States)

    Charbonneau, Mathieu

    2013-12-01

    The use of physical models of molecular structures as research tools has been central to the development of biochemistry and molecular biology. Intriguingly, it has received little attention from scholars of science. In this paper, I argue that these physical models are not mere three-dimensional representations but that they are in fact very special research tools: they are cognitive augmentations. Despite the fact that they are external props, these models serve as cognitive tools that augment and extend the modeler's cognitive capacities and performance in molecular modeling tasks. This cognitive enhancement is obtained because of the way the modeler interacts with these models, the models' materiality contributing to the solving of the molecule's structure. Furthermore, I argue that these material models and their component parts were designed, built and used specifically to serve as cognitive facilitators and cognitive augmentations.

  2. Transcriptional Network Architecture of Breast Cancer Molecular Subtypes

    Science.gov (United States)

    de Anda-Jáuregui, Guillermo; Velázquez-Caldelas, Tadeo E.; Espinal-Enríquez, Jesús; Hernández-Lemus, Enrique

    2016-01-01

    Breast cancer heterogeneity is evident at the clinical, histological and molecular level. High throughput technologies allowed the identification of intrinsic subtypes that capture transcriptional differences among tumors. A remaining question is whether said differences are associated to a particular transcriptional program which involves different connections between the same molecules. In other words, whether particular transcriptional network architectures can be linked to specific phenotypes. In this work we infer, construct and analyze transcriptional networks from whole-genome gene expression microarrays, by using an information theory approach. We use 493 samples of primary breast cancer tissue classified in four molecular subtypes: Luminal A, Luminal B, Basal and HER2-enriched. For comparison, a network for non-tumoral mammary tissue (61 samples) is also inferred and analyzed. Transcriptional networks present particular architectures in each breast cancer subtype as well as in the non-tumor breast tissue. We find substantial differences between the non-tumor network and those networks inferred from cancer samples, in both structure and gene composition. More importantly, we find specific network architectural features associated to each breast cancer subtype. Based on breast cancer networks' centrality, we identify genes previously associated to the disease, either, generally (i.e., CNR2) or to a particular subtype (such as LCK). Similarly, we identify LUZP4, a gene barely explored in breast cancer, playing a role in transcriptional networks with subtype-specific relevance. With this approach we observe architectural differences between cancer and non-cancer at network level, as well as differences between cancer subtype networks which might be associated with breast cancer heterogeneity. The centrality measures of these networks allow us to identify genes with potential biomedical implications to breast cancer. PMID:27920729

  3. Transcriptional Network Architecture of Breast Cancer Molecular Subtypes

    Directory of Open Access Journals (Sweden)

    Guillermo de Anda-Jáuregui

    2016-11-01

    Full Text Available Breast cancer heterogeneity is evident at the clinical, histological and molecular level. High throughput technologies allowed the identification of intrinsic subtypes that capture transcriptional differences among tumors. A remaining question is whether said differences are associated to a particular transcriptional program which involves different connections between the same molecules. In other words, whether particular transcriptional network architectures can be linked to specific phenotypes.In this work we infer, construct and analyze transcriptional networks from whole-genome gene expression microarrays, by using an information theory approach. We use 493 samples of primary breast cancer tissue classified in four molecular subtypes: Luminal A, Luminal B, Basal and HER2-enriched. For comparison, a network for non-tumoral mammary tissue (61 samples is also inferred and analyzed.Transcriptional networks present particular architectures in each breast cancer subtype as well as in the non-tumor breast tissue. We find substantial differences between the non-tumor network and those networks inferred from cancer samples, in both structure and gene composition. More importantly, we find specific network architectural features associated to each breast cancer subtype. Based on breast cancer networks' centrality, we identify genes previously associated to the disease, either, generally (i.e. CNR2 or to a particular subtype (such as LCK. Similarly, we identify LUZP4, a gene barely explored in breast cancer, playing a role in transcriptional networks with subtype-specific relevance.With this approach we observe architectural differences between cancer and non-cancer at network level, as well as differences between cancer subtype networks which might be associated with breast cancer heterogeneity. The centrality measures of these networks allow us to identify genes with potential biomedical implications to breast cancer.

  4. Transcriptional Network Architecture of Breast Cancer Molecular Subtypes.

    Science.gov (United States)

    de Anda-Jáuregui, Guillermo; Velázquez-Caldelas, Tadeo E; Espinal-Enríquez, Jesús; Hernández-Lemus, Enrique

    2016-01-01

    Breast cancer heterogeneity is evident at the clinical, histological and molecular level. High throughput technologies allowed the identification of intrinsic subtypes that capture transcriptional differences among tumors. A remaining question is whether said differences are associated to a particular transcriptional program which involves different connections between the same molecules. In other words, whether particular transcriptional network architectures can be linked to specific phenotypes. In this work we infer, construct and analyze transcriptional networks from whole-genome gene expression microarrays, by using an information theory approach. We use 493 samples of primary breast cancer tissue classified in four molecular subtypes: Luminal A, Luminal B, Basal and HER2-enriched. For comparison, a network for non-tumoral mammary tissue (61 samples) is also inferred and analyzed. Transcriptional networks present particular architectures in each breast cancer subtype as well as in the non-tumor breast tissue. We find substantial differences between the non-tumor network and those networks inferred from cancer samples, in both structure and gene composition. More importantly, we find specific network architectural features associated to each breast cancer subtype. Based on breast cancer networks' centrality, we identify genes previously associated to the disease, either, generally (i.e., CNR2) or to a particular subtype (such as LCK). Similarly, we identify LUZP4, a gene barely explored in breast cancer, playing a role in transcriptional networks with subtype-specific relevance. With this approach we observe architectural differences between cancer and non-cancer at network level, as well as differences between cancer subtype networks which might be associated with breast cancer heterogeneity. The centrality measures of these networks allow us to identify genes with potential biomedical implications to breast cancer.

  5. Mechanisms of environmental chemicals that enable the cancer hallmark of evasion of growth suppression

    Science.gov (United States)

    Nahta, Rita; Al-Mulla, Fahd; Al-Temaimi, Rabeah; Amedei, Amedeo; Andrade-Vieira, Rafaela; Bay, Sarah; G. Brown, Dustin; Calaf, Gloria M.; Castellino, Robert C.; Cohen-Solal, Karine A.; Colacci, Annamaria; Cruickshanks, Nichola; Dent, Paul; Di Fiore, Riccardo; Forte, Stefano; Goldberg, Gary S.; Hamid, Roslida A.; Krishnan, Harini; Laird, Dale W.; Lasfar, Ahmed; Marignani, Paola A.; Memeo, Lorenzo; Mondello, Chiara; Naus, Christian C.; Ponce-Cusi, Richard; Raju, Jayadev; Roy, Debasish; Roy, Rabindra; P. Ryan, Elizabeth; Salem, Hosni K.; Scovassi, A. Ivana; Singh, Neetu; Vaccari, Monica; Vento, Renza; Vondráček, Jan; Wade, Mark; Woodrick, Jordan; Bisson, William H.

    2015-01-01

    As part of the Halifax Project, this review brings attention to the potential effects of environmental chemicals on important molecular and cellular regulators of the cancer hallmark of evading growth suppression. Specifically, we review the mechanisms by which cancer cells escape the growth-inhibitory signals of p53, retinoblastoma protein, transforming growth factor-beta, gap junctions and contact inhibition. We discuss the effects of selected environmental chemicals on these mechanisms of growth inhibition and cross-reference the effects of these chemicals in other classical cancer hallmarks. PMID:26106139

  6. Quantum mechanics of molecular rate processes

    CERN Document Server

    Levine, Raphael D

    1999-01-01

    This survey of applications of the theory of collisions and rate processes to molecular problems explores collisions of molecules with internal structure, generalized Ehrenfest theorem, theory of reactive collisions, and role of symmetry. It also reviews partitioning technique, equivalent potentials and quasibound states, theory of direct reactions, more. 1969 edition.

  7. Quantum Mechanics/Molecular Mechanics Study of the Sialyltransferase Reaction Mechanism.

    Science.gov (United States)

    Hamada, Yojiro; Kanematsu, Yusuke; Tachikawa, Masanori

    2016-10-11

    The sialyltransferase is an enzyme that transfers the sialic acid moiety from cytidine 5'-monophospho-N-acetyl-neuraminic acid (CMP-NeuAc) to the terminal position of glycans. To elucidate the catalytic mechanism of sialyltransferase, we explored the potential energy surface along the sialic acid transfer reaction coordinates by the hybrid quantum mechanics/molecular mechanics method on the basis of the crystal structure of sialyltransferase CstII. Our calculation demonstrated that CstII employed an SN1-like reaction mechanism via the formation of a short-lived oxocarbenium ion intermediate. The computational barrier height was 19.5 kcal/mol, which reasonably corresponded with the experimental reaction rate. We also found that two tyrosine residues (Tyr156 and Tyr162) played a vital role in stabilizing the intermediate and the transition states by quantum mechanical interaction with CMP.

  8. Molecular genetics and genomics progress in urothelial bladder cancer.

    Science.gov (United States)

    Netto, George J

    2013-11-01

    The clinical management of solid tumor patients has recently undergone a paradigm shift as the result of the accelerated advances in cancer genetics and genomics. Molecular diagnostics is now an integral part of routine clinical management in lung, colon, and breast cancer patients. In a disappointing contrast, molecular biomarkers remain largely excluded from current management algorithms of urologic malignancies. The need for new treatment alternatives and validated prognostic molecular biomarkers that can help clinicians identify patients in need of early aggressive management is pressing. Identifying robust predictive biomarkers that can stratify response to newly introduced targeted therapeutics is another crucially needed development. The following is a brief discussion of some promising candidate biomarkers that may soon become a part of clinical management of bladder cancers.

  9. Molecular therapy of colorectal cancer: progress and future directions.

    Science.gov (United States)

    Weng, Wenhao; Feng, Junlan; Qin, Huanlong; Ma, Yanlei

    2015-02-01

    Colorectal cancer (CRC) remains one of the most common types of cancer and leading causes of cancer death worldwide. Although the introduction of cytotoxic drugs such as oxaliplatin, irinotecan and fluorouracil has improved the treatment of advanced CRC, the individual response to chemoradiotherapy varies tremendously from one patient to another. However, recent progress in CRC molecular therapies may provide new insight into the treatment of this disease. Currently, components of the EGFR, VEGF, Wnt and NF-kB pathways are the most important targets for CRC therapy. This review chronicles the development of molecular CRC therapies over the past few decades. We also provide an update on the current progress of research concerning the molecular pathways leading to CRC and discuss the possible implications for CRC therapy.

  10. Molecular targeted agents for gastric and gastroesophageal junction cancer.

    Science.gov (United States)

    Oshima, Takashi; Masuda, Munetaka

    2012-04-01

    Despite recent improvements in surgical techniques and chemotherapy, advanced cancers of the stomach and gastroesophageal junction (GEJ) continue to have poor clinical outcomes. However, molecules intimately related to cancer cell proliferation, invasion, and metastasis have been studied as candidates for molecular targeted agents. Target molecules, such as the epidermal growth factor receptor, vascular endothelial growth factor receptor, and P13k/Akt/mTor pathway, as well as the insulin-like growth factor receptor, c-Met pathways, fibroblast growth factor receptor, and other pathways are considered to be promising candidates for molecular targeted therapy for gastric and GEJ cancer. In this review we focus on the recent developments in targeting relevant pathways in these types of cancer.

  11. CD24 as a Molecular Marker in Ovarian Cancer: A Literature Review

    Directory of Open Access Journals (Sweden)

    Lu Huang

    2016-01-01

    Full Text Available Ovarian cancer is the most lethal gynecologic cancer, with a mortality rate of > 60%. Cancer stem cell (CSC hypothesis offers an attractive explanation of chemoresistance, metastasis, etc., associated with the disease. However, there are still controversy and limitation in defining the CSC markers. CD24 is a mucin-type glycosyl-phosphatidylinositol-linked glycoprotein, expressed on the surface of cells, which serves as a normal receptor for P-selectin and is found involved in molecular adhesion and metastatic tumor spread. Expression rate of CD24 has been associated with progression of various cancers and poor survival rates. In this review, the function of CD24 in ovarian cancer, especially in ovarian CSC system, was discussed in an effort to broaden the interpretation of potential mechanism.

  12. Molecular Cell Biology of Apoptosis and Necroptosis in Cancer.

    Science.gov (United States)

    Dillon, Christopher P; Green, Douglas R

    2016-01-01

    Cell death is a major mechanism to eliminate cells in which DNA is damaged, organelles are stressed, or oncogenes are overexpressed, all events that would otherwise predispose cells to oncogenic transformation. The pathways that initiate and execute cell death are complex, genetically encoded, and subject to significant regulation. Consequently, while these pathways are often mutated in malignancy, there is considerable interest in inducing cell death in tumor cells as therapy. This chapter addresses our current understanding of molecular mechanisms contributing to two cell death pathways, apoptotic cell death and necroptosis, a regulated form of necrotic cell death. Apoptosis can be induced by a wide variety of signals, leading to protease activation that dismantles the cell. We discuss the physiological importance of each apoptosis pathway and summarize their known roles in cancer suppression and the current efforts at targeting each pathway therapeutically. The intricate mechanistic link between death receptor-mediated apoptosis and necroptosis is described, as well as the potential opportunities for utilizing necroptosis in the treatment of malignancy.

  13. Cellular and molecular processes in ovarian cancer metastasis. A Review in the Theme: Cell and Molecular Processes in Cancer Metastasis.

    Science.gov (United States)

    Yeung, Tsz-Lun; Leung, Cecilia S; Yip, Kay-Pong; Au Yeung, Chi Lam; Wong, Stephen T C; Mok, Samuel C

    2015-10-01

    Ovarian cancer is the most lethal gynecological malignancy. It is usually diagnosed at a late stage, with a 5-yr survival rate of metastasis. Although metastasis plays a crucial role in promoting ovarian tumor progression and decreasing patient survival rates, the underlying mechanisms of ovarian cancer spread have yet to be thoroughly explored. For many years, researchers have believed that ovarian cancer metastasizes via a passive mechanism by which ovarian cancer cells are shed from the primary tumor and carried by the physiological movement of peritoneal fluid to the peritoneum and omentum. However, the recent discovery of hematogenous metastasis of ovarian cancer to the omentum via circulating tumor cells instigated rethinking of the mode of ovarian cancer metastasis and the importance of the "seed-and-soil" hypothesis for ovarian cancer metastasis. In this review we discuss the possible mechanisms by which ovarian cancer cells metastasize from the primary tumor to the omentum, the cross-talk signaling events between ovarian cancer cells and various stromal cells that play crucial roles in ovarian cancer metastasis, and the possible clinical implications of these findings in the management of this deadly, highly metastatic disease.

  14. The Landscape of Pancreatic Cancer Therapeutic Resistance Mechanisms.

    Science.gov (United States)

    Chand, Saswati; O'Hayer, Kevin; Blanco, Fernando F; Winter, Jordan M; Brody, Jonathan R

    2016-01-01

    Pancreatic cancer (pancreatic ductal adenocarcinoma, PDA) is infamously moving to the top of the list as one of the most lethal cancers with an overall 5 year survival rate of 7%. Multiple genomic-based and molecular characterization studies of PDA specimens and established animal models have provided the field with multiple targets and a progression model of this disease. Still, to date, the best therapeutic options are surgery and combination cytotoxic therapies. In general, even in the best case scenario (i.e., an early stage diagnosis and a response to a specific therapy), most of these fortunate patients' PDA cells acquire or exert resistance mechanisms and eventually kill the patient. Herein, we touch on a growing field of investigation that focuses on PDA cell therapeutic resistance mechanisms. We examine extrinsic elements (i.e., the tumor microenvironment, hypoxia) to the intrinsic processes within the cell (i.e., post-transcriptional gene regulation and somatic mutations) that are important for therapeutic efficacy and resistance. Even as better targeted and personalized approaches move through the clinical trial pipeline the discussed resistance mechanisms will most likely play a role in the management of this deadly disease.

  15. Molecular mechanisms involved in convergent crop domestication.

    Science.gov (United States)

    Lenser, Teresa; Theißen, Günter

    2013-12-01

    Domestication has helped to understand evolution. We argue that, vice versa, novel insights into evolutionary principles could provide deeper insights into domestication. Molecular analyses have demonstrated that convergent phenotypic evolution is often based on molecular changes in orthologous genes or pathways. Recent studies have revealed that during plant domestication the causal mutations for convergent changes in key traits are likely to be located in particular genes. These insights may contribute to defining candidate genes for genetic improvement during the domestication of new plant species. Such efforts may help to increase the range of arable crops available, thus increasing crop biodiversity and food security to help meet the predicted demands of the continually growing global population under rapidly changing environmental conditions.

  16. Transcriptional networks inferred from molecular signatures of breast cancer.

    Science.gov (United States)

    Tongbai, Ron; Idelman, Gila; Nordgard, Silje H; Cui, Wenwu; Jacobs, Jonathan L; Haggerty, Cynthia M; Chanock, Stephen J; Børresen-Dale, Anne-Lise; Livingston, Gary; Shaunessy, Patrick; Chiang, Chih-Hung; Kristensen, Vessela N; Bilke, Sven; Gardner, Kevin

    2008-02-01

    Global genomic approaches in cancer research have provided new and innovative strategies for the identification of signatures that differentiate various types of human cancers. Computational analysis of the promoter composition of the genes within these signatures may provide a powerful method for deducing the regulatory transcriptional networks that mediate their collective function. In this study we have systematically analyzed the promoter composition of gene classes derived from previously established genetic signatures that recently have been shown to reliably and reproducibly distinguish five molecular subtypes of breast cancer associated with distinct clinical outcomes. Inferences made from the trends of transcription factor binding site enrichment in the promoters of these gene groups led to the identification of regulatory pathways that implicate discrete transcriptional networks associated with specific molecular subtypes of breast cancer. One of these inferred pathways predicted a role for nuclear factor-kappaB in a novel feed-forward, self-amplifying, autoregulatory module regulated by the ERBB family of growth factor receptors. The existence of this pathway was verified in vivo by chromatin immunoprecipitation and shown to be deregulated in breast cancer cells overexpressing ERBB2. This analysis indicates that approaches of this type can provide unique insights into the differential regulatory molecular programs associated with breast cancer and will aid in identifying specific transcriptional networks and pathways as potential targets for tumor subtype-specific therapeutic intervention.

  17. Colorectal Cancer & Molecular Mutations and Polymorphism

    Directory of Open Access Journals (Sweden)

    Aga Syed Sameer

    2013-05-01

    Full Text Available Colorectal cancer (CRC is one of the major causes of mortality and morbidity, and is the third most common cancer in men and the second most common cancer in women worldwide. The incidence of CRC shows considerable variation among racially or ethnically defined populations in multiracial/ethnic countries. The tumorigenesis of CRC is either because of the chromosomal instability (CIN or microsatellite instability (MIN or involving various proto-oncogenes, tumor suppressor genes and also epigenetic changes in the DNA. In this review I have focused on the mutations and polymorphisms of various important genes of the CIN and MIN pathways which have been implicated in the development of CRC.

  18. Correlation of morphological and molecular parameters for colon cancer

    Science.gov (United States)

    Yuan, Shuai; Roney, Celeste A.; Li, Qian; Jiang, James; Cable, Alex; Summers, Ronald M.; Chen, Yu

    2010-02-01

    Colorectal cancer (CRC) is the second leading cause of cancer death in the United States. There is great interest in studying the relationship among microstructures and molecular processes of colorectal cancer during its progression at early stages. In this study, we use our multi-modality optical system that could obtain co-registered optical coherence tomography (OCT) and fluorescence molecular imaging (FMI) images simultaneously to study CRC. The overexpressed carbohydrate α-L-fucose on the surfaces of polyps facilitates the bond of adenomatous polyps with UEA-1 and is used as biomarker. Tissue scattering coefficient derived from OCT axial scan is used as quantitative value of structural information. Both structural images from OCT and molecular images show spatial heterogeneity of tumors. Correlations between those values are analyzed and demonstrate that scattering coefficients are positively correlated with FMI signals in conjugated. In UEA-1 conjugated samples (8 polyps and 8 control regions), the correlation coefficient is ranged from 0.45 to 0.99. These findings indicate that the microstructure of polyps is changed gradually during cancer progression and the change is well correlated with certain molecular process. Our study demonstrated that multi-parametric imaging is able to simultaneously detect morphology and molecular information and it can enable spatially and temporally correlated studies of structure-function relationships during tumor progression.

  19. Chemopreventive functions and molecular mechanisms of garlic organosulfur compounds.

    Science.gov (United States)

    Trio, Phoebe Zapanta; You, Sixiang; He, Xi; He, Jianhua; Sakao, Kozue; Hou, De-Xing

    2014-05-01

    Garlic (Allium sativum L.) has long been used both for culinary and medicinal purposes by many cultures. Population and preclinical investigations have suggested that dietary garlic intake has health benefits, such as lowering the risk of esophageal, stomach and prostate cancers. Extensive studies from laboratory and animal models have revealed that garlic has a wide range of biological activities, and garlic organosulfur compounds (OSCs) are responsible for the biological activities. However, the presence and potency of garlic OSCs vary with respect to the mode of garlic preparation and extraction. Cooked or processed garlic products showed different kinds of garlic OSCs, some of which are highly unstable and instantly decomposed. These facts, possibly gave paradoxical results on the garlic effects. In this review, we first summarized the biotransformation processes of garlic alliin into different garlic OSCs as well as the garlic OSCs compositions from different garlic preparations. Next, we reviewed the chemopreventive functions and molecular mechanisms focusing on the anti-inflammation, antioxidation, anti-diabetes and anticancer activity behind different garlic OSCs.

  20. Comparative Proteomic Analysis of Anti-Cancer Mechanism by Periplocin Treatment in Lung Cancer Cells

    Directory of Open Access Journals (Sweden)

    Zejun Lu

    2014-03-01

    Full Text Available Background: Periplocin is used for treatment of rheumatoid arthritis, reinforcement of bones and tendons, palpitations or shortness of breath and lower extremity edema in traditional medicine. Our previous findings suggested that periplocin could inhibit the growth of lung cancer both in vitro and in vivo. But the biological processes and molecular pathways by which periplocin induces these beneficial effects remain largely undefined. Methods: To explore the molecular mechanisms of periplocin involved in anti-cancer activity, in the present study the protein profile changes of human lung cancer cell lines A549 in response to periplocin treatment were investigated using the proteomics approaches (2-DE combined with MS/MS. Western blot was employed to verify the changed proteins. Interactions between changed proteins were analyzed by STRING. Results: 29 down-regulated protein species named GTP-binding nuclear protein Ran (RAN, Rho GDP-dissociation inhibitor 1 (ARHGDIA, eukaryotic translation initiation factor 5A-1 (EIF5A and Profilin-1(PFN1, and 10 up-regulated protein species named Heat shock cognate 71 kDa protein (HSPA8,10 kDa heat shock protein (HSPE1, and Cofilin-1(CFL-1 were identified. Among them, GTP-binding nuclear protein Ran (RAN and Rho GDP-dissociation inhibitor 1 (ARHGDIA were the most significantly changed (over tenfold. The proteasome subunit beta type-6 (PSMB6, ATP synthase ecto-α-subunit (ATP5A1, Aldehyde dehydrogenase 1 (ALDH1 and EIF5A were verified by immunoblot assays to be dramatically down-regulated. By STRING bioinformatics analysis revealing interactions and signaling networks it became apparent that the proteins changed they are primarily involved in transcription and proteolysis. Conclusion: Periplocin inhibited growth of lung cancer by down-regulating proteins, such as ATP5A1, EIF5A, ALDH1 and PSMB6. These findings may improve our understanding of the molecular mechanisms underlying the anti-cancer effects of

  1. [New molecular classification of colorectal cancer, pancreatic cancer and stomach cancer: Towards "à la carte" treatment?].

    Science.gov (United States)

    Dreyer, Chantal; Afchain, Pauline; Trouilloud, Isabelle; André, Thierry

    2016-01-01

    This review reports 3 of recently published molecular classifications of the 3 main gastro-intestinal cancers: gastric, pancreatic and colorectal adenocarcinoma. In colorectal adenocarcinoma, 6 independent classifications were combined to finally hold 4 molecular sub-groups, Consensus Molecular Subtypes (CMS 1-4), linked to various clinical, molecular and survival data. CMS1 (14% MSI with immune activation); CMS2 (37%: canonical with epithelial differentiation and activation of the WNT/MYC pathway); CMS3 (13% metabolic with epithelial differentiation and RAS mutation); CMS4 (23%: mesenchymal with activation of TGFβ pathway and angiogenesis with stromal invasion). In gastric adenocarcinoma, 4 groups were established: subtype "EBV" (9%, high frequency of PIK3CA mutations, hypermetylation and amplification of JAK2, PD-L1 and PD-L2), subtype "MSI" (22%, high rate of mutation), subtype "genomically stable tumor" (20%, diffuse histology type and mutations of RAS and genes encoding integrins and adhesion proteins including CDH1) and subtype "tumors with chromosomal instability" (50%, intestinal type, aneuploidy and receptor tyrosine kinase amplification). In pancreatic adenocarcinomas, a classification in four sub-groups has been proposed, stable subtype (20%, aneuploidy), locally rearranged subtype (30%, focal event on one or two chromosoms), scattered subtype (36%,200 structural variation events, defects in DNA maintenance). Although currently away from the care of patients, these classifications open the way to "à la carte" treatment depending on molecular biology.

  2. Molecular Mechanisms of Sex Determination in Reptiles

    OpenAIRE

    Rhen, T; Schroeder, A

    2010-01-01

    Charles Darwin first provided a lucid explanation of how gender differences evolve nearly 140 years ago. Yet, a disconnect remains between his theory of sexual selection and the mechanisms that underlie the development of males and females. In particular, comparisons between representatives of different phyla (i.e., flies and mice) reveal distinct genetic mechanisms for sexual differentiation. Such differences are hard to comprehend unless we study organisms that bridge the phylogenetic gap. ...

  3. Molecular functions and significance of the MTA family in hormone-independent cancer.

    Science.gov (United States)

    Ning, Zhifeng; Gan, Jinfeng; Chen, Chaoying; Zhang, Dianzheng; Zhang, Hao

    2014-12-01

    The members of the metastasis-associated protein (MTA) family play pivotal roles in both physiological and pathophysiological processes, especially in cancer development and metastasis, and their role as master regulators has come to light. Due to the fact that they were first identified as crucial factors in estrogen receptor-mediated breast cancer metastasis, most of the early studies focused on their hormone-dependent functions. However, the accumulating evidence shows that the members of MTA family are deregulated in most, if not all, the cancers studied so far. Therefore, the levels as well as the activities of the MTA family members are widely accepted as potential biomarkers for diagnosis, prognosis, and predictors of overall survival. They function differently in different cancers with specific mechanisms. p53 and HIF-1α appear to be the respectively common upstream and downstream regulator of the MTA family in both development and metastasis of a wide spectrum of cancers. Here, we review the expression and clinical significance of the MTA family, focusing on hormone-independent cancers. To illustrate the molecular mechanisms, we analyze the MTA family-related signaling pathways in different cancers. Finally, targeting the MTA family directly or the pathways involved in the MTA family indirectly could be invaluable strategies in the development of cancer therapeutics.

  4. Advanced imaging of colorectal cancer: From anatomy to molecular imaging

    OpenAIRE

    García-Figueiras, Roberto; Baleato-González, Sandra; Padhani, Anwar R.; Marhuenda, Ana; Luna, Antonio; Alcalá, Lidia; Carballo-Castro, Ana; Álvarez-Castro, Ana

    2016-01-01

    Abstract Imaging techniques play a key role in the management of patients with colorectal cancer. The introduction of new advanced anatomical, functional, and molecular imaging techniques may improve the assessment of diagnosis, prognosis, planning therapy, and assessment of response to treatment of these patients. Functional and molecular imaging techniques in clinical practice may allow the assessment of tumour-specific characteristics and tumour heterogeneity. This paper will review recent...

  5. A novel mechanism of methylglyoxal cytotoxicity in prostate cancer cells.

    Science.gov (United States)

    Antognelli, Cinzia; Mezzasoma, Letizia; Fettucciari, Katia; Talesa, Vincenzo Nicola

    2013-04-01

    Methylglyoxal is one of the most powerful glycating agents of proteins and other important cellular components and has been shown to be toxic to cultured cells. Methylglyoxal cytotoxicity appears to occur through cell-cycle arrest but, more often, through induction of apoptosis. In this study we examined whether, and through which molecular mechanism, methylglyoxal affects the growth of poorly aggressive LNCaP and invasive PC3 human prostate cancer cells, where its role has not been exhaustively investigated yet. We demonstrated that methylglyoxal is cytotoxic on LNCaP and PC3 and that such cytotoxicity occurs not via cell proliferation but apoptosis control. Moreover, we demonstrated that methylglyoxal cytotoxicity, potentiated by the silencing of its major scavenging enzyme Glyoxalase I, occurred via different apoptotic responses in LNCaP and PC3 cells that also showed a different susceptibility to this metabolite. Finally, we showed that the observed methylglyoxal apoptogenic role involved different molecular pathways, specifically mediated by methylglyoxal or methylglyoxal-derived argpyrimidine intracellular accumulation and NF-kB signaling-pathway. In particular, in LNCaP cells, methylglyoxal, through the accumulation of argpyrimidine, desensitized the key cell survival NF-kB signaling pathway, which was consistent with the modulation of NF-kB-regulated genes, triggering a mitochondrial apoptotic pathway. The results suggest that this physiological compound merits investigation as a potential chemo-preventive/-therapeutic agent, in differently aggressive prostate cancers.

  6. Molecular markers as therapeutic targets in lung cancer

    Institute of Scientific and Technical Information of China (English)

    Hsin-Hui Tseng; Biao He

    2013-01-01

    Lung cancer is responsible for 29% of cancer deaths in the United States and has very low 5-year survival rates of approximately 11% in men and 15% in women.Although the early diagnosis of lung cancer may increase the survival rate with adequate treatment,advanced lung cancers are often metastasized and receive limited benefit from therapeutic regimens.As conventional treatments for lung cancer reach their limitations,researchers have attempted to discover novel drug therapies aimed at specific targets contributing to the progression of tumorigenesis.Recent advances in systems biology have enabled the molecular biology of lung carcinogenesis to be elucidated.Our understanding of the physiologic processes of tumor development provide a means to design more effective and specific drugs with less toxicity,thereby accelerating the delivery of new drug therapies to the patient's bedside.

  7. Clinical variability and molecular heterogeneity in prostate cancer

    Directory of Open Access Journals (Sweden)

    Jonathan Shoag

    2016-01-01

    Full Text Available Prostate cancer is a clinically heterogeneous disease, with some men having indolent disease that can safely be observed, while others have aggressive, lethal disease. Over the past decade, researchers have begun to unravel some of the genomic heterogeneity that contributes to these varying clinical phenotypes. Distinct molecular sub-classes of prostate cancer have been identified, and the uniqueness of these sub-classes has been leveraged to predict clinical outcomes, design novel biomarkers for prostate cancer diagnosis, and develop novel therapeutics. Recent work has also elucidated the temporal and spatial heterogeneity of prostate cancer, helping us understand disease pathogenesis, response to therapy, and progression. New genomic techniques have provided us with a window into the remarkable clinical and genomic heterogeneity of prostate cancer, and this new perspective will increasingly impact patient care.

  8. Symposium on molecular and cellular mechanisms of mutagenesis

    Energy Technology Data Exchange (ETDEWEB)

    1981-01-01

    These proceedings contain abstracts only of the 21 papers presented at the Sympsoium. The papers dealt with molecular mechanisms of mutagenesis and cellular responses to chemical and physical mutagenic agents. (ERB)

  9. [Advances of molecular targeted therapy in squamous cell lung cancer].

    Science.gov (United States)

    Ma, Li; Zhang, Shucai

    2013-12-01

    Squamous cell lung cancer (SQCLC) is one of the most prevalent subtypes of lung cancer worldwide, about 400,000 persons die from squamous-cell lung cancer around the world, and its pathogenesis is closely linked with tobacco exposure. Unfortunately, squamous-cell lung cancer patients do not benefit from major advances in the development of targeted therapeutics such as epidermal growth factor receptor (EGFR) inhibitors or anaplastic lymphoma kinase (ALK) inhibitors that show exquisite activity in lung adenocarcinomas with EGFR mutations or echinoderm microtubule associated protein like-4 (EML4)-ALK fusions, respectively. Major efforts have been launched to characterize the genomes of squamous-cell lung cancers. Among the new results emanating from these efforts are amplifications of the fibroblast growth factor receptor 1 (FGFR1) gene, the discoidin domain receptor 2 (DDR2) gene mutation as potential novel targets for the treatment of SQCLCs. Researchers find that there are many specific molecular targeted genes in the genome of squamous-cell lung cancer patients. These changes play a vital role in cell cycle regulation, oxidative stress, cell apoptosis, squamous epithelium differentiation, may be the candidate targeted moleculars in SQCLCs. Here, we provide a review on these discoveries and their implications for clinical trials in squamous-cell lung cancer assessing the value of novel therapeutics addressing these targets.

  10. Molecular Markers for Breast Cancer: Prediction on Tumor Behavior

    Directory of Open Access Journals (Sweden)

    Bruna Karina Banin Hirata

    2014-01-01

    Full Text Available Breast cancer is one of the most common cancers with greater than 1,300,000 cases and 450,000 deaths each year worldwide. The development of breast cancer involves a progression through intermediate stages until the invasive carcinoma and finally into metastatic disease. Given the variability in clinical progression, the identification of markers that could predict the tumor behavior is particularly important in breast cancer. The determination of tumor markers is a useful tool for clinical management in cancer patients, assisting in diagnostic, staging, evaluation of therapeutic response, detection of recurrence and metastasis, and development of new treatment modalities. In this context, this review aims to discuss the main tumor markers in breast carcinogenesis. The most well-established breast molecular markers with prognostic and/or therapeutic value like hormone receptors, HER-2 oncogene, Ki-67, and p53 proteins, and the genes for hereditary breast cancer will be presented. Furthermore, this review shows the new molecular targets in breast cancer: CXCR4, caveolin, miRNA, and FOXP3, as promising candidates for future development of effective and targeted therapies, also with lower toxicity.

  11. Molecular-Genetic Aspects of Breast Cancer

    Directory of Open Access Journals (Sweden)

    Krasteva M.

    2014-12-01

    Full Text Available Breast cancer is the most frequent malignancy among women. Advances in breast cancer knowledge have deciphered the involvement of a number of tumor suppressor genes and proto-oncogenes in disease pathogenesis. These genes are part of the complex biochemical pathways, which enable cell cycle control and maintenance of genome integrity. Their function may be disrupted as a result of alterations in gene sequence or misregulation of gene expression including alterations in DNA methylation pattern. The present review summarizes the main findings on major breast cancer related genes BRCA1/2, p53, ATM, CHEK2, HER2, PIK3CA and their tumorigenic inactivation/activation. The potential clinical importance of these genes with respect to patients’ prognosis and therapy are also discussed. The possible implication of other putative breast cancer related genes is also outlined. The first elaborate data on the genetic and epigenetic status of the above mentioned genes concerning Bulgarian patients with the sporadic form of the disease are presented. The studies indicate for a characteristic mutational spectrum in some of the genes for the Bulgarian patients and specific correlation between the status of different genes and clinicopathological characteristics.

  12. Oncogenic miR-544 is an important molecular target in gastric cancer.

    Science.gov (United States)

    Zhi, Qiaoming; Guo, Xiaobo; Guo, Lei; Zhang, Rongjuan; Jiang, Jinling; Ji, Jun; Zhang, Jianian; Zhang, Jun; Chen, Xuehua; Cai, Qu; Li, Jianfang; Liu, Bingya; Zhu, Zhenggang; Yu, Yingyan

    2013-02-01

    MicroRNAs (miRNAs) and promoter hypermethylation are vital epigenetic mechanisms for transcriptional inactivation of tumor suppressor. IRX1 is a newly identified tumor suppressor gene and hypermethylation involves the decreased expression in gastric cancer. However, the microRNA regulatory mechanism on IRX1 expression is still unclear. In this study, we report an IRX1-targeting miRNA-544, which directly targets 3'-UTR of IRX1 gene by luciferase reporter assay. miR-544 suppresses the protein expression of IRX1 gene by Western blot and immunocytochemistry. Ectopic expression of miR-544 promotes cell proliferation and cell cycle progression significantly in vitro on gastric cancer cells. The study suggests that miR-544 is an oncogenic microRNA in gastric cancer. Over expression of miR-544 contributes to the inactivation and low-expression of IRX1 in gastric cancer. These findings are helpful for clarifying the molecular mechanisms involved in gastric carcinogenesis and indicate that miR-544 is a key regulator in switching cell cycle on or off. miR-544 may be a potential molecular target in miRNA-based strategy on gastric cancer.

  13. Molecular and cellular mechanisms of pulmonary fibrosis

    Directory of Open Access Journals (Sweden)

    Todd Nevins W

    2012-07-01

    Full Text Available Abstract Pulmonary fibrosis is a chronic lung disease characterized by excessive accumulation of extracellular matrix (ECM and remodeling of the lung architecture. Idiopathic pulmonary fibrosis is considered the most common and severe form of the disease, with a median survival of approximately three years and no proven effective therapy. Despite the fact that effective treatments are absent and the precise mechanisms that drive fibrosis in most patients remain incompletely understood, an extensive body of scientific literature regarding pulmonary fibrosis has accumulated over the past 35 years. In this review, we discuss three broad areas which have been explored that may be responsible for the combination of altered lung fibroblasts, loss of alveolar epithelial cells, and excessive accumulation of ECM: inflammation and immune mechanisms, oxidative stress and oxidative signaling, and procoagulant mechanisms. We discuss each of these processes separately to facilitate clarity, but certainly significant interplay will occur amongst these pathways in patients with this disease.

  14. Review on the Applications and Molecular Mechanisms of Xihuang Pill in Tumor Treatment

    Directory of Open Access Journals (Sweden)

    Qiujun Guo

    2015-01-01

    Full Text Available Xihuang pill (XH is a complementary and alternative medicine that has been used in traditional Chinese medicine (TCM for the treatment of tumors since the 18th century. XH has clinical effects on non-Hodgkin lymphoma, breast cancer, gastric cancer, liver cancer, and bone metastasis. XH can also inhibit the growth of tumor cells and cancer stem cells, prevent tumor invasion and angiogenesis, and regulate the tumor microenvironment. XH is composed of Ru Xiang (olibanum, Mo Yao (Commiphora myrrha, She Xiang (Moschus, and Niu Huang (Calculus bovis. Some of the compounds found in these ingredients exert multiple antitumor effects and may synergize with the other ingredients. We aimed to summarize the clinical applications and molecular mechanisms of XH and its chemical composition. This review will provide potential new strategies and alternative perspectives for tumor treatments and basic research into complementary and alternative medicine.

  15. An Overview of Carcinogenic Heavy Metal: Molecular Toxicity Mechanism and Prevention

    Science.gov (United States)

    Kim, Hyun Soo; Kim, Yeo Jin; Seo, Young Rok

    2015-01-01

    Almost all heavy metals are serious toxicants as carcinogens. However, due to their chemical and physiological properties, heavy metals are useful in industrial areas including alloy, smelting and production of commercial products. Such applications increase the opportunity for heavy metal exposure. Waste from industrial processes is also a major source of environmental contamination and accumulation in the human body. Arsenic, cadmium, chromium, and nickel are classified as group 1 carcinogens by the International Agency for Research on Cancer, and are utilized commercially. In this review, we used molecular pathway analysis to understand the toxicity and carcinogenic mechanisms of these metals. Our analyzed data showed that above-mentioned metallic substances induce oxidative stress, DNA damage, and cell death processes, resulting in increase the risk of cancer and cancer-related diseases. Thus, we might think phytochelatin molecules and antioxidative phytochemical substances are helpful for prevention of heavy metal-induced cancer. PMID:26734585

  16. Review on the Applications and Molecular Mechanisms of Xihuang Pill in Tumor Treatment.

    Science.gov (United States)

    Guo, Qiujun; Lin, Jinyin; Liu, Rui; Gao, Yebo; He, Shulin; Xu, Xinyao; Hua, Baojin; Li, Conghuang; Hou, Wei; Zheng, Honggang; Bao, Yanju

    2015-01-01

    Xihuang pill (XH) is a complementary and alternative medicine that has been used in traditional Chinese medicine (TCM) for the treatment of tumors since the 18th century. XH has clinical effects on non-Hodgkin lymphoma, breast cancer, gastric cancer, liver cancer, and bone metastasis. XH can also inhibit the growth of tumor cells and cancer stem cells, prevent tumor invasion and angiogenesis, and regulate the tumor microenvironment. XH is composed of Ru Xiang (olibanum), Mo Yao (Commiphora myrrha), She Xiang (Moschus), and Niu Huang (Calculus bovis). Some of the compounds found in these ingredients exert multiple antitumor effects and may synergize with the other ingredients. We aimed to summarize the clinical applications and molecular mechanisms of XH and its chemical composition. This review will provide potential new strategies and alternative perspectives for tumor treatments and basic research into complementary and alternative medicine.

  17. Molecular mechanisms of STIM/Orai communication

    Science.gov (United States)

    Derler, Isabella; Jardin, Isaac

    2016-01-01

    Ca2+ entry into the cell via store-operated Ca2+ release-activated Ca2+ (CRAC) channels triggers diverse signaling cascades that affect cellular processes like cell growth, gene regulation, secretion, and cell death. These store-operated Ca2+ channels open after depletion of intracellular Ca2+ stores, and their main features are fully reconstituted by the two molecular key players: the stromal interaction molecule (STIM) and Orai. STIM represents an endoplasmic reticulum-located Ca2+ sensor, while Orai forms a highly Ca2+-selective ion channel in the plasma membrane. Functional as well as mutagenesis studies together with structural insights about STIM and Orai proteins provide a molecular picture of the interplay of these two key players in the CRAC signaling cascade. This review focuses on the main experimental advances in the understanding of the STIM1-Orai choreography, thereby establishing a portrait of key mechanistic steps in the CRAC channel signaling cascade. The focus is on the activation of the STIM proteins, the subsequent coupling of STIM1 to Orai1, and the consequent structural rearrangements that gate the Orai channels into the open state to allow Ca2+ permeation into the cell. PMID:26825122

  18. TCGA divides gastric cancer into four molecular subtypes:implications for individualized therapeutics

    Institute of Scientific and Technical Information of China (English)

    Wei Zhang

    2014-01-01

    Gastric cancer is a leading cause of cancer deaths in the world. The treatment of gastric cancer is chalenging because of its highly heterogeneous etiology and clinical characteristics. Recent genomic and molecular characterization of gastric cancer, especialy the findings reported by the Cancer Genome Atlas (TCGA), have shed light on the heterogeneity and potential targeted therapeutics for four different subtypes of gastric cancer.

  19. Multi-modality molecular imaging for gastric cancer research

    Science.gov (United States)

    Liang, Jimin; Chen, Xueli; Liu, Junting; Hu, Hao; Qu, Xiaochao; Wang, Fu; Nie, Yongzhan

    2011-12-01

    Because of the ability of integrating the strengths of different modalities and providing fully integrated information, multi-modality molecular imaging techniques provide an excellent solution to detecting and diagnosing earlier cancer, which remains difficult to achieve by using the existing techniques. In this paper, we present an overview of our research efforts on the development of the optical imaging-centric multi-modality molecular imaging platform, including the development of the imaging system, reconstruction algorithms and preclinical biomedical applications. Primary biomedical results show that the developed optical imaging-centric multi-modality molecular imaging platform may provide great potential in the preclinical biomedical applications and future clinical translation.

  20. Molecular imaging of cancer using PET and SPECT

    DEFF Research Database (Denmark)

    Kjaer, Andreas

    2006-01-01

    for molecular imaging of cancer. Especially the possibility of a quick transfer of methods developed in animals to patients (translational research) is an important strength. This article will briefly discuss the newest applications and their importance and perspective in relation to the shift in paradigm......Molecular imaging allows for the study of molecular and cellular events in the living intact organism. The nuclear medicine methodologies of positron emission tomography (PET) and single photon emission computer tomography (SPECT) posses several advantages, which make them particularly suited...

  1. Normal and disease-related biological functions of Twist1 and underlying molecular mechanisms

    Institute of Scientific and Technical Information of China (English)

    Qian Qin; Young Xu; Tao He; Chunlin Qin; Jianming Xu

    2012-01-01

    This article reviews the molecular structure,expression pattern,physiological function,pathological roles and molecular mechanisms of Twist1 in development,genetic disease and cancer.Twist1 is a basic helix-loop-helix domaincontaining transcription factor.It forms homo- or hetero-dimers in order to bind the Nde1 E-box element and activate or repress its target genes.During development,Twistl is essential for mesoderm specification and differentiation.Heterozygous loss-of-function mutations of the human Twist1 gene cause several diseases including the SaethreChotzen syndrome.The Twist1-null mouse embryos die with unclosed cranial neural tubes and defective head mesenchyme,somites and limb buds.Twist1 is expressed in breast,liver,prostate,gastric and other types of cancers,and its expression is usually associated with invasive and metastatic cancer phenotypes.In cancer cells,Twistl is upregulated by multiple factors including SRC-1,STAT3,MSX2,HIF-1α,integrin-linked kinase and NF-κB.Twist1 significantly enhances epithelial-mesenchymal transition (EMT) and cancer cell migration and invasion,hence promoting cancer metastasis.Twistl promotes EMT in part by directly repressing E-cadherin expression by recruiting the nucleosome remodeling and deacetylase complex for gene repression and by upregulating Bmil,AKT2,YB-1,etc.Emerging evidence also suggests that Twist1 plays a role in expansion and chemotherapeutic resistance of cancer stem cells.Further understanding of the mechanisms by which Twist1 promotes metastasis and identification of Twist1 functional modulators may hold promise for developing new strategies to inhibit EMT and cancer metastasis.

  2. Male sex determination: insights into molecular mechanisms

    Institute of Scientific and Technical Information of China (English)

    Kathryn McClelland; Josephine Bowles; Peter Koopman

    2012-01-01

    Disorders of sex development often arise from anomalies in the molecular or cellular networks that guide the differentiation of the embryonic gonad into either a testis or an ovary,two functionally distinct organs.The activation of the Y-linked gene Sry(sexdetermining region Y) and its downstream target Sox9 (Sry box-containinggene 9) triggers testis differentiation by stimulating the differentiation of Sertoli cells,which then direct testis morphogenesis.Once engaged,a genetic pathway promotes the testis development while actively suppressing genes involved in ovarian development.This review focuses on the events of testis determination and the struggle to maintain male fate in the face of antagonistic pressure from the underlying female programme.

  3. Mechanism of Molecular Exchange in Copolymer Micelles

    Science.gov (United States)

    Choi, Soo-Hyung; Lodge, Timothy; Bates, Frank

    2010-03-01

    Compared to thermodynamic structure, much less has been known about the kinetics of block copolymer micelles which should underlay the attainment of thermodynamic equilibrium. In this presentation, molecular exchange between spherical micelles formed by isotopically labeled diblock copolymers was investigated using time-resolved small-angle neutron scattering. Two pairs of structurally matched poly(styrene-b-ethylene-alt-propylene) (PS-PEP) were synthesized and dispersed in isotopic mixture of squalane, highly selective to PEP block. Each pair includes polymers with fully deuterated (dPS-PEP) and a normal (hPS-PEP) PS blocks. Temperature dependence of the micelle exchange rate R(t) is consistent with melt dynamics for the core polymer. Furthermore, R(t) is significantly sensitive to the core block length N due to the thermodynamic penalty associated with ejecting a core block into the solvent. This hypersensitivity, combined with modest polydispersity in N, leads to an approximately logarithmic decay in R(t).

  4. Molecular Imaging of Breast Cancer: Present and future directions

    Directory of Open Access Journals (Sweden)

    David eAlcantara

    2014-12-01

    Full Text Available Medical imaging technologies have undergone explosive growth over the past few decades and now play a central role in clinical oncology. But the truly transformative power of imaging in the clinical management of cancer patients lies ahead. Today, imaging is at a crossroads, with molecularly targeted imaging agents expected to broadly expand the capabilities of conventional anatomical imaging methods. Molecular imaging will allow clinicians to not only see where a tumour is located in the body, but also to visualize the expression and activity of specific molecules (e.g. proteases and protein kinases and biological processes (e.g. apoptosis, angiogenesis, and metastasis that influence tumour behavior and/or response to therapy. Breast cancer, the most common cancer among women and a research area where our group is actively involved, is a very heterogeneous disease with diverse patterns of development and response to treatment. Hence, molecular imaging is expected to have a major impact on this type of cancer, leading to important improvements in diagnosis, individualized treatment, and drug development, as well as our understanding of how breast cancer arises.

  5. Molecular Characterization of Indolent Prostate Cancer

    Science.gov (United States)

    2015-10-01

    Luo, Ph.D. CONTRACTING ORGANIZATION: Johns Hopkins University Baltimore, MD 21218-2680 REPORT DATE: October 2015 TYPE OF REPORT: Annual...DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. 1. REPORT DATE October 2015 2. REPORT TYPE Annual Report 3. DATES COVERED 15 Sep 2014- 14 Sep 2015...detected at biopsy , leading to the contemporary problem of prostate cancer over-diagnosis and over-treatment. The objective of the project is to

  6. Miniature and Molecularly Specific Optical Screening Technologies for Breast Cancer

    Science.gov (United States)

    2008-10-01

    and molecular contrast in breast cancer V. Millon SR, Provenzano PP, Elicieri, KW, Brown, JQ, Keely, PJ, Ramanujam, N. "Imaging of ALA-induced PpIX...calculating tissue optical properties. Part I: Theory and validation on synthetic phantoms. Appl Opt, 2006. 45(5): p. 1062-71. 4. Baumann, M., C

  7. Immunophenotyping invasive breast cancer: paving the road for molecular imaging.

    NARCIS (Netherlands)

    Vermeulen, J.F.; Brussel, A.S. van; Groep, P. van der; Morsink, F.H.; Bult, P.; Wall, E. van der; Diest, P.J. van

    2012-01-01

    ABSTRACT: BACKGROUND: Mammographic population screening in The Netherlands has increased the number of breast cancer patients with small and non-palpable breast tumors. Nevertheless, mammography is not ultimately sensitive and specific for distinct subtypes. Molecular imaging with targeted tracers m

  8. Molecular prostate cancer pathology: current issues and achievements.

    NARCIS (Netherlands)

    Schalken, J.A.; Bergh, A. von; Bono, A.V.; Foster, C.; Gospadarowicz, M.; Isaacs, W.B.; Rubin, M.; Schroder, F.H.; Tribukait, B.; Tsukamotot, T.; Wiklund, P.

    2005-01-01

    Recent developments in the field of molecular techniques have provided new tools that have led to the discovery of many new promising biomarkers for prostate cancer. These biomarkers may be instrumental in the development of new tests that will have a high specificity for the diagnosis and prognosis

  9. Methodologies in cancer cytogenetics and molecular cytogenetics.

    Science.gov (United States)

    Wang, Nancy

    2002-10-30

    Various types of cytogenetic and molecular cytogenetic approaches, including conventional banding, fluorescence in situ hybridization (FISH), fiber-FISH, comparative genomic hybridization (CGH), matrix array CGH, chromosome microdissection, and microcell-mediated chromosome transfer are summarized. The rationale, advantage, and limitations of each approach are discussed with respect to research and clinical applications in human neoplasia.

  10. Molecular Pathways: Isocitrate Dehydrogenase Mutations in Cancer.

    Science.gov (United States)

    Clark, Owen; Yen, Katharine; Mellinghoff, Ingo K

    2016-04-15

    IDH1 and IDH2 are homodimeric enzymes that catalyze the conversion of isocitrate to α-ketoglutarate (α-KG) and concomitantly produce reduced NADPH from NADP(+) Mutations in the genes encoding IDH1 and IDH2 have recently been found in a variety of human cancers, most commonly glioma, acute myeloid leukemia (AML), chondrosarcoma, and intrahepatic cholangiocarcinoma. The mutant protein loses its normal enzymatic activity and gains a new ability to produce the "oncometabolite" R(-)-2-hydroxyglutarate (R-2-HG). R-2-HG competitively inhibits α-KG-dependent enzymes which play crucial roles in gene regulation and tissue homeostasis. Expression of mutant IDH impairs cellular differentiation in various cell lineages and promotes tumor development in cooperation with other cancer genes. First-generation inhibitors of mutant IDH have entered clinical trials, and have shown encouraging results in patients with IDH-mutant AML. This article summarizes recent progress in our understanding of the role of mutant IDH in tumorigenesis.Clin Cancer Res; 22(8); 1837-42. ©2016 AACR.

  11. Vancomycin Molecular Interactions: Antibiotic and Enantioselective Mechanisms

    Science.gov (United States)

    Ward, Timothy J.; Gilmore, Aprile; Ward, Karen; Vowell, Courtney

    Medical studies established that vancomycin and other related macrocyclic antibiotics have an enhanced antimicrobial activity when they are associated as dimers. The carbohydrate units attached to the vancomycin basket have an essential role in the dimerization reaction. Covalently synthesized dimers were found active against vancomycin-resistant bacterial strains. A great similarity between antibiotic potential and enantioselectivity was established. A covalent vancomycin dimer was studied in capillary electrophoresis producing excellent chiral separation of dansyl amino acids. Balhimycin is a macrocyclic glycopeptide structurally similar to vancomycin. The small differences are, however, responsible for drastic differences in enantioselectivity in the same experimental conditions. Contributions from studies examining vancomycin's mechanism for antimicrobial activity have substantially aided our understanding of its mechanism in chiral recognition.

  12. Molecular Mechanisms of Lymphocyte-Mediated Cytotoxicity

    Institute of Scientific and Technical Information of China (English)

    Zusen Fan; Qixiang Zhang

    2005-01-01

    Granule-mediated cytotoxicity is the major mechanism for lymphocytes to kill viruses, intracellular bacteria and tumors. The cytotoxic granules move to the immunological synapse by exocytosis after recognition of a killer cell.The contents of the granules are delivered into target cells with the help of perforin by endocytosis. A group of serine protease granzymes cleave their critical substrates to initiate DNA damage and cell death. The most abundant granzymes are granzyme A and B. They induce cell death through alternate and nonoverlapping pathways. The substrates and functions of the majority of the orphan granzymes have not yet been identified. It is possible that the diversity of granzymes provides fail-safe mechanisms for killing viruses and tumor cells.

  13. Molecular imaging of cell-mediated cancer immunotherapy.

    Science.gov (United States)

    Lucignani, Giovanni; Ottobrini, Luisa; Martelli, Cristina; Rescigno, Maria; Clerici, Mario

    2006-09-01

    New strategies based on the activation of a patient's immune response are being sought to complement present conventional exogenous cancer therapies. Elucidating the trafficking pathways of immune cells in vivo, together with their migratory properties in relation to their differentiation and activation status, is useful for understanding how the immune system interacts with cancer. Methods based on tissue sampling to monitor immune responses are inadequate for repeatedly characterizing the responses of the immune system in different organs. A solution to this problem might come from molecular and cellular imaging - a branch of biomedical sciences that combines biotechnology and imaging methods to characterize, in vivo, the molecular and cellular processes involved in normal and pathologic states. The general concepts of noninvasive imaging of targeted cells as well as the technology and probes applied to cell-mediated cancer immunotherapy imaging are outlined in this review.

  14. Molecular Mechanisms of Mechanosensitivity in Focal Adhesions

    OpenAIRE

    2016-01-01

    Physical environment guides tissue regeneration and morphology in both health and disease. In the past three decades, several experiments illustrated that mechanical cues are captured and transduced to biochemical signals in the cellular level (mechanotransduction) mediated by cell adhesion. Cells adhere to their microenvironment through large protein assemblies known as focal adhesions that directly couple intra- and extra-cellular matrices and play a critical role in many vital cell functio...

  15. Epigenetic Markers for Molecular Detection of Prostate Cancer

    Directory of Open Access Journals (Sweden)

    Vera L. Costa

    2007-01-01

    Full Text Available Prostate cancer is a highly prevalent malignancy, which is clinically silent but curable while organ-confined. Because available screening methods show poor sensitivity and specificity, the development of new molecular markers is warranted. Epigenetic alterations, mainly promoter hypermethylation of cancer-related genes, are common events in prostate cancer and might be used as cancer biomarkers. Moreover, the development of quantitative, high-throughput techniques to assess promoter methylation enabled the simultaneous screening of multiple clinical samples. From the numerous cancer-related genes hypermethylated in prostate cancer only a few proved to be strong candidates to become routine biomarkers. This small set of genes includes GSTP1, APC, RARβ2, Cyclin D2, MDR1, and PTGS2. Single and/or multigene analyses demonstrated the feasibility of detecting early prostate cancer, with high sensitivity and specificity, in body fluids (serum, plasma, urine, and ejaculates and tissue samples. In addition, quantitative hypermethylation of several genes has been associated with clinicopathologic features of tumor aggressiveness, and also reported as independent prognostic factor for relapse. The identification of age-related methylation at specific loci and the differential frequency of methylation among ethnical groups, also provided interesting data linking methylation and prostate cancer risk. Although large trials are needed to validate these findings, the clinical use of these markers might be envisaged for the near future.

  16. Evolving molecularly targeted therapies for advanced-stage thyroid cancers.

    Science.gov (United States)

    Bible, Keith C; Ryder, Mabel

    2016-07-01

    Increased understanding of disease-specific molecular targets of therapy has led to the regulatory approval of two drugs (vandetanib and cabozantinib) for the treatment of medullary thyroid cancer (MTC), and two agents (sorafenib and lenvatinib) for the treatment of radioactive- iodine refractory differentiated thyroid cancer (DTC) in both the USA and in the EU. The effects of these and other therapies on overall survival and quality of life among patients with thyroid cancer, however, remain to be more-clearly defined. When applied early in the disease course, intensive multimodality therapy seems to improve the survival outcomes of patients with anaplastic thyroid cancer (ATC), but salvage therapies for ATC are of uncertain benefit. Additional innovative, rationally designed therapeutic strategies are under active development both for patients with DTC and for patients with ATC, with multiple phase II and phase III randomized clinical trials currently ongoing. Continued effort is being made to identify further signalling pathways with potential therapeutic relevance in thyroid cancers, as well as to elaborate on the complex interactions between signalling pathways, with the intention of translating these discoveries into effective and personalized therapies. Herein, we summarize the progress made in molecular medicine for advanced-stage thyroid cancers of different histotypes, analyse how these developments have altered - and might further refine - patient care, and identify open questions for future research.

  17. Advances of Molecular Targeted Therapy in Squamous Cell Lung Cancer

    Directory of Open Access Journals (Sweden)

    Li MA

    2013-12-01

    Full Text Available Squamous cell lung cancer (SQCLC is one of the most prevalent subtypes of lung cancer worldwide, about 400,000 persons die from squamous-cell lung cancer around the world, and its pathogenesis is closely linked with tobacco exposure. Unfortunately, squamous-cell lung cancer patients do not benefit from major advances in the development of targeted therapeutics such as epidermal growth factor receptor (EGFR inhibitors or anaplastic lymphoma kinase (ALK inhibitors that show exquisite activity in lungadenocarcinomas with EGFR mutations or echinoderm microtubule associated protein like-4 (EML4-ALK fusions, respectively. Major efforts have been launched to characterize the genomes of squamous-cell lung cancers. Among the new results emanating from these efforts are amplifications of the fibroblast growth factor receptor 1 (FGFR1 gene, the discoidin domain receptor 2 (DDR2 gene mutation as potential novel targets for the treatment of SQCLCs. Researchers find that there are many specific molecular targeted genes in the genome of squamous-cell lung cancer patients. These changes play a vital role in cell cycle regulation, oxidative stress, cell apoptosis, squamous epithelium differentiation, may be the candidate targeted moleculars in SQCLCs. Here, we provide a review on these discoveries and their implications for clinical trials in squamous-cell lungcancer assessing the value of novel therapeutics addressing these targets.

  18. Pathological Bases for a Robust Application of Cancer Molecular Classification

    Directory of Open Access Journals (Sweden)

    Salvador J. Diaz-Cano

    2015-04-01

    Full Text Available Any robust classification system depends on its purpose and must refer to accepted standards, its strength relying on predictive values and a careful consideration of known factors that can affect its reliability. In this context, a molecular classification of human cancer must refer to the current gold standard (histological classification and try to improve it with key prognosticators for metastatic potential, staging and grading. Although organ-specific examples have been published based on proteomics, transcriptomics and genomics evaluations, the most popular approach uses gene expression analysis as a direct correlate of cellular differentiation, which represents the key feature of the histological classification. RNA is a labile molecule that varies significantly according with the preservation protocol, its transcription reflect the adaptation of the tumor cells to the microenvironment, it can be passed through mechanisms of intercellular transference of genetic information (exosomes, and it is exposed to epigenetic modifications. More robust classifications should be based on stable molecules, at the genetic level represented by DNA to improve reliability, and its analysis must deal with the concept of intratumoral heterogeneity, which is at the origin of tumor progression and is the byproduct of the selection process during the clonal expansion and progression of neoplasms. The simultaneous analysis of multiple DNA targets and next generation sequencing offer the best practical approach for an analytical genomic classification of tumors.

  19. Molecular mechanisms of somatostatin receptor trafficking.

    Science.gov (United States)

    Csaba, Zsolt; Peineau, Stéphane; Dournaud, Pascal

    2012-02-01

    The neuropeptide somatostatin (SRIF) is an important modulator of neurotransmission in the central nervous system and acts as a potent inhibitor of hormone and exocrine secretion. In addition, SRIF regulates cell proliferation in normal and tumorous tissues. The six somatostatin receptor subtypes (sst1, sst2A, sst2B, sst3, sst4, and sst5), which belong to the G protein-coupled receptor (GPCR) family, share a common molecular topology: a hydrophobic core of seven transmembrane-spanning α-helices, three intracellular loops, three extracellular loops, an amino-terminus outside the cell, and a carboxyl-terminus inside the cell. For most of the GPCRs, intracytosolic sequences, and more particularly the C-terminus, are believed to interact with proteins that are mandatory for either exporting neosynthesized receptor, anchoring receptor at the plasma membrane, internalization, recycling, or degradation after ligand binding. Accordingly, most of the SRIF receptors can traffic not only in vitro within different cell types but also in vivo. A picture of the pathways and proteins involved in these processes is beginning to emerge.

  20. Molecular mechanisms of male germ cell differentiation.

    Science.gov (United States)

    Hecht, N B

    1998-07-01

    During spermatogenesis, diploid stem cells differentiate, undergo meiosis, and transform into haploid spermatozoa. As this precisely timed series of events proceeds, chromosomal ploidy is reduced and the nucleosomes of the chromatin are replaced by a transcriptionally quiescent protamine-containing nucleus. The premature termination of transcription during the haploid phase of spermatogenesis necessitates an especially prominent role for posttranscriptional regulation in the temporal and spatial expression of many testis-specific proteins and isozymes. In this review article, discussion will focus on novel mechanisms regulating gene expression in mammalian male germ cells from genome to protein.

  1. Application of Proteomics to Cancer Molecular Diagnostics

    Institute of Scientific and Technical Information of China (English)

    Sam HANASH

    2009-01-01

    @@ Strategies to achieve personalized medicine and improve public health encompass assessment of an individual's risk for disease, early detection and molecular classification of disease resulting in an informed choice of the most appropriate treatment instituted at an early stage of disease develop- ment. A major contribution of proteomics in this field is the development of blood based tests to achieve the goals of personalized medicine.

  2. Targets and mechanisms of berberine, a natural drug with potential to treat cancer with special focus on breast cancer.

    Science.gov (United States)

    Jabbarzadeh Kaboli, Parham; Rahmat, Asmah; Ismail, Patimah; Ling, King-Hwa

    2014-10-05

    Breast cancer is the most common cancer among women worldwide and novel therapeutic agents are needed to treat this disease. The plant-based alkaloid berberine has potential therapeutic applications for breast cancer, although a better understanding of the genes and cellular pathways regulated by this compound is needed to define the mechanism of its action in cancer treatment. In this review, the molecular targets of berberine in various cancers, particularly breast cancer, are discussed. Berberine was shown to be effective in inhibiting cell proliferation and promoting apoptosis in various cancerous cells. Some signaling pathways affected by berberine, including the MAP (mitogen-activated protein) kinase and Wnt/β-catenin pathways, are critical for reducing cellular migration and sensitivity to various growth factors. This review will discuss recent studies and consider the application of new prospective approaches based on microRNAs and other crucial regulators for use in future studies to define the action of berberine in cancer. The effects of berberine on cancer cell survival and proliferation are also outlined.

  3. Molecular Determinants of Hormone Refractory Prostate Cancer

    Science.gov (United States)

    2013-07-01

    to known prostate cancer oncogenes, Never In Mitosis A (NIMA) related kinase 6 (NEK6) reproducibly yielded androgen-independent tumors in female...constitutively active MEK, RAF1, ERBB2, AKT1, PIM1 and PIM2), overexpression of the Never In Mitosis A (NIMA) related kinase 6 (NEK6) reproducibly yielded...Never In Mitosis A (NIMA) related kinase 6 (NEK6), and nemo-like kinase (NLK). Aim 1. Elucidating the role of NIMA-related kinase 6 (NEK6) and nemo

  4. Molecular-targeted therapy for elderly patients with advanced non-small cell lung cancer.

    Science.gov (United States)

    Antonelli, Giovanna; Libra, Massimo; Panebianco, Vincenzo; Russo, Alessia Erika; Vitale, Felice Vito; Colina, Paolo; D'Angelo, Alessandro; Rossello, Rosalba; Ferraù, Francesco

    2016-01-01

    Lung cancer is the most common cause of cancer-related mortality in men and women. Non-small cell lung cancer (NSCLC) represents close to 90% of all lung cancers. When diagnosed, >50% of patients are >65 years old. Through an improved understanding of the molecular mechanisms involved in lung oncogenesis, molecular-targeted approaches have become an essential element for the treatment of patients with NSCLC. As the toxicity profiles of the techniques are definitely more favorable compared with chemotherapy, they are particularly attractive for use in elderly patients, who are potentially more susceptible to the toxicity of systemic oncological therapies. However, studies on the activity of molecular-targeted agents in this aged patient setting are much more limited compared with those in their younger counterparts. In the present review, the literature on molecular-targeted therapy for elderly patients with advanced NSCLC is discussed. It is concluded that bevacizumab should be reserved only for highly select elderly patients with advanced NSCLC when the clinician deems it useful in the face of acceptable toxicities. In elderly patients with advanced epidermal growth factor receptor mutation-positive NSCLC, erlotinib and gefitinib appear to repeat the same favorable performance as that documented on a larger scale in the overall population of patients with activating mutations. A good toxicity profile is also confirmed for active molecules on different pathways, such as crizotinib.

  5. Mechanical properties of fibroblasts depend on level of cancer transformation.

    Science.gov (United States)

    Efremov, Yu M; Lomakina, M E; Bagrov, D V; Makhnovskiy, P I; Alexandrova, A Y; Kirpichnikov, M P; Shaitan, K V

    2014-05-01

    Recently, it was revealed that tumor cells are significantly softer than normal cells. Although this phenomenon is well known, it is connected with many questions which are still unanswered. Among these questions are the molecular mechanisms which cause the change in stiffness and the correlation between cell mechanical properties and their metastatic potential. We studied mechanical properties of cells with different levels of cancer transformation. Transformed cells in three systems with different transformation types (monooncogenic N-RAS, viral and cells of tumor origin) were characterized according to their morphology, actin cytoskeleton and focal adhesion organization. Transformation led to reduction of cell spreading and thus decreasing the cell area, disorganization of actin cytoskeleton, lack of actin stress fibers and decline in the number and size of focal adhesions. These alterations manifested in a varying degree depending on type of transformation. Force spectroscopy by atomic force microscopy with spherical probes was carried out to measure the Young's modulus of cells. In all cases the Young's moduli were fitted well by log-normal distribution. All the transformed cell lines were found to be 40-80% softer than the corresponding normal ones. For the cell system with a low level of transformation the difference in stiffness was less pronounced than for the two other systems. This suggests that cell mechanical properties change upon transformation, and acquisition of invasive capabilities is accompanied by significant softening.

  6. Molecular Pathways: Cachexia Signaling-A Targeted Approach to Cancer Treatment.

    Science.gov (United States)

    Miyamoto, Yuji; Hanna, Diana L; Zhang, Wu; Baba, Hideo; Lenz, Heinz-Josef

    2016-08-15

    Cancer cachexia is a multifactorial syndrome characterized by an ongoing loss of skeletal muscle mass, which negatively affects quality of life and portends a poor prognosis. Numerous molecular substrates and mechanisms underlie the dysregulation of skeletal muscle synthesis and degradation observed in cancer cachexia, including proinflammatory cytokines (TNFα, IL1, and IL6), and the NF-κB, IGF1/AKT/mTOR, and myostatin/activin-SMAD pathways. Recent preclinical and clinical studies have demonstrated that anti-cachexia drugs (such as MABp1 and soluble receptor antagonist of myostatin/activin) not only prevent muscle wasting but also may prolong overall survival. In this review, we focus on the significance of cachexia signaling in patients with cancer and highlight promising drugs targeting tumor cachexia in clinical development. Clin Cancer Res; 22(16); 3999-4004. ©2016 AACR.

  7. Membrane curvature in cell biology: An integration of molecular mechanisms.

    Science.gov (United States)

    Jarsch, Iris K; Daste, Frederic; Gallop, Jennifer L

    2016-08-15

    Curving biological membranes establishes the complex architecture of the cell and mediates membrane traffic to control flux through subcellular compartments. Common molecular mechanisms for bending membranes are evident in different cell biological contexts across eukaryotic phyla. These mechanisms can be intrinsic to the membrane bilayer (either the lipid or protein components) or can be brought about by extrinsic factors, including the cytoskeleton. Here, we review examples of membrane curvature generation in animals, fungi, and plants. We showcase the molecular mechanisms involved and how they collaborate and go on to highlight contexts of curvature that are exciting areas of future research. Lessons from how membranes are bent in yeast and mammals give hints as to the molecular mechanisms we expect to see used by plants and protists.

  8. Molecular Mechanisms of Circadian Regulation During Spaceflight

    Science.gov (United States)

    Zanello, S. B.; Boyle, R.

    2012-01-01

    The physiology of both vertebrates and invertebrates follows internal rhythms coordinated in phase with the 24-hour daily light cycle. This circadian clock is governed by a central pacemaker, the suprachiasmatic nucleus (SCN) in the brain. However, peripheral circadian clocks or oscillators have been identified in most tissues. How the central and peripheral oscillators are synchronized is still being elucidated. Light is the main environmental cue that entrains the circadian clock. Under the absence of a light stimulus, the clock continues its oscillation in a free-running condition. In general, three functional compartments of the circadian clock are defined. The vertebrate retina contains endogenous clocks that control many aspects of retinal physiology, including retinal sensitivity to light, neurohormone synthesis (melatonin and dopamine), rod disk shedding, signalling pathways and gene expression. Neurons with putative local circadian rhythm generation are found among all the major neuron populations in the mammalian retina. In the mouse, clock genes and function are more localized to the inner retinal and ganglion cell layers. The photoreceptor, however, secrete melatonin which may still serve a an important circadian signal. The reception and transmission of the non-visual photic stimulus resides in a small subpopulation (1-3%) or retinal ganglion cells (RGC) that express the pigment melanopsin (Opn4) and are called intrisically photoreceptive RGC (ipRGC). Melanopsin peak absorption is at 420 nm and all the axons of the ipRGC reach the SCN. A common countermeasure for circadian re-entrainment utilizes blue-green light to entrain the circadian clock and mitigate the risk of fatigue and health and performance decrement due to circadian rhythm disruption. However, an effective countermeasure targeting the photoreceptor system requires that the basic circadian molecular machinery remains intact during spaceflight. We hypothesize that spaceflight may affect ip

  9. Quantum Mechanics/Molecular Mechanics Free Energy Maps and Nonadiabatic Simulations for a Photochemical Reaction in DNA: Cyclobutane Thymine Dimer.

    Science.gov (United States)

    Mendieta-Moreno, Jesús I; Trabada, Daniel G; Mendieta, Jesús; Lewis, James P; Gómez-Puertas, Paulino; Ortega, José

    2016-11-03

    The absorption of ultraviolet radiation by DNA may result in harmful genetic lesions that affect DNA replication and transcription, ultimately causing mutations, cancer, and/or cell death. We analyze the most abundant photochemical reaction in DNA, the cyclobutane thymine dimer, using hybrid quantum mechanics/molecular mechanics (QM/MM) techniques and QM/MM nonadiabatic molecular dynamics. We find that, due to its double helix structure, DNA presents a free energy barrier between nonreactive and reactive conformations leading to the photolesion. Moreover, our nonadiabatic simulations show that most of the photoexcited reactive conformations return to standard B-DNA conformations after an ultrafast nonradiative decay to the ground state. This work highlights the importance of dynamical effects (free energy, excited-state dynamics) for the study of photochemical reactions in biological systems.

  10. [Molecular mechanisms of skeletal muscle hypertrophy].

    Science.gov (United States)

    Astratenkova, I V; Rogozkin, V A

    2014-06-01

    Enzymes Akt, AMPK, mTOR, S6K and PGC-1a coactivator take part in skeletal muscles in the regulation of synthesis of proteins. The expression of these proteins is regulated by growth factors, hormones, nutrients, mechanical loading and leads to an increase in muscle mass and skeletal muscle hypertrophy. The review presents the results of studies published in the past four years, which expand knowledge on the effects of various factors on protein synthesis in skeletal muscle. The attention is focused on the achievements that reveal and clarify the signaling pathways involved in the regulation of protein synthesis in skeletal muscle. The central place is taken by mTOR enzyme which controls and regulates the main stages of the cascade of reactions of muscle proteins providing synthesis in the conditions of human life. coactivator PGC-1a.

  11. Nutritional links to plausible mechanisms underlying pancreatic cancer: a conference report.

    Science.gov (United States)

    Hine, R Jean; Srivastava, Sudhir; Milner, John A; Ross, Sharon A

    2003-11-01

    Adenocarcinoma of the pancreas is one of most catastrophic and least understood of cancers. Evidence from clinical studies indicates that the development of pancreas cancer progresses over many years before symptoms appear. Most people with pancreatic cancer die within six months of diagnosis. The lack of early disease markers, the paucity of direct subject/patient interview data and limited availability of high quality biological samples have slowed progress toward identifying environmental and genetic disease risk factors. Much remains to be learned about the development of pancreatic cancer and about potential interventions for disease prevention. Epidemiological and mechanistic studies examining risk factors for pancreatic cancer supply little consistent or strong evidence to provide a cohesive prevention strategy for this cancer, but offer clues for future research concerning the prevention and early detection of this devastating disease. This Executive Summary provides background discussion on pancreatic cancer and summaries of each of the topics discussed at the workshop, including 1) Molecular aspects, 2) Dietary and other risk factors for pancreatic cancer, 3) The metabolic hypothesis for pancreatic cancer, 4) Preclinical studies on pancreatic cancer, 5) Methylation, 6) Oxidative stress and 7) Biomarker Profiling. This document also contains a compilation of recommendations for future research, concluding remarks, a list of speakers and participants attending the workshop, and a selection of key references to aid future research into nutritional links to mechanisms underlying pancreas cancer. The recommendations section suggests gaps in current knowledge and articulates future directions for this area of investigation.

  12. Molecular mechanisms of ETS transcription factor-mediated tumorigenesis.

    Science.gov (United States)

    Kar, Adwitiya; Gutierrez-Hartmann, Arthur

    2013-01-01

    The E26 transformation-specific (ETS) family of transcription factors is critical for development, differentiation, proliferation and also has a role in apoptosis and tissue remodeling. Changes in expression of ETS proteins therefore have a significant impact on normal physiology of the cell. Transcriptional consequences of ETS protein deregulation by overexpression, gene fusion, and modulation by RAS/MAPK signaling are linked to alterations in normal cell functions, and lead to unlimited increased proliferation, sustained angiogenesis, invasion and metastasis. Existing data show that ETS proteins control pathways in epithelial cells as well as stromal compartments, and the crosstalk between the two is essential for normal development and cancer. In this review, we have focused on ETS factors with a known contribution in cancer development. Instead of focusing on a prototype, we address cancer associated ETS proteins and have highlighted the diverse mechanisms by which they affect carcinogenesis. Finally, we discuss strategies for ETS factor targeting as a potential means for cancer therapeutics.

  13. Substrate binding and catalytic mechanism in phospholipase C from Bacillus cereus. a molecular mechanics and molecular dynamics study

    DEFF Research Database (Denmark)

    da Graça Thrige, D; Buur, J R; Jørgensen, Flemming Steen

    1997-01-01

    For the first time a consistent catalytic mechanism of phospholipase C from Bacillus cereus is reported based on molecular mechanics calculations. We have identified the position of the nucleophilic water molecule, which is directly involved in the hydrolysis of the natural substrate phosphatidyl...

  14. Molecular mechanisms of alcohol associated pancreatitis

    Institute of Scientific and Technical Information of China (English)

    Dahn; L; Clemens; Mark; A; Wells; Katrina; J; Schneider; Shailender; Singh

    2014-01-01

    Alcohol abuse is commonly associated with the development of both acute and chronic pancreatitis. Despite this close association, the fact that only a small percentage of human beings who abuse alcohol develop pancreatitis indicates that alcohol abuse alone is not sufficient to initiate clinical pancreatitis. This contention is further supported by the fact that administration of ethanol to experimental animals does not cause pancreatitis. Because of these findings, it is widely believed that ethanol sensitizes the pancreas to injury and additional factors trigger the development of overt pancreatitis. How ethanol sensitizes the pancreas to pancreatitis is not entirely known. Numerous studies have demonstrated that ethanol and its metabolites have a number of deleterious effects on acinar cells. Important acinar cells properties that are affected by ethanol include: calcium signaling, secretion of zymogens, autophagy, cellular regeneration, the unfolded protein response, and mitochondrial membrane integrity. In addition to the actions of ethanol on acinar cells, it is apparent that ethanol also affects pancreatic stellatecells. Pancreatic stellate cells have a critical role in normal tissue repair and the pathologic fibrotic response. Given that ethanol and its metabolites affect so many pancreatic functions, and that all of these effects occur simultaneously, it is likely that none of these effects is "THE" effect. Instead, it is most likely that the cumulative effect of ethanol on the pancreas predisposes the organ to pancreatitis. The focus of this article is to highlight some of the important mechanisms by which ethanol alters pancreatic functions and may predispose the pancreas to disease.

  15. Molecular markers and targets for colorectal cancer prevention

    Institute of Scientific and Technical Information of China (English)

    Naveena B JANAKIRAM; Chinthalapally V RAO

    2008-01-01

    Colorectal cancer is the third most prevalent cancer in the world. If detected at an early stage, treatment often might lead to cure. As prevention is better than cure, epidemiological studies reveal that having a healthy diet often protects from pro-moting/developing cancer. An important consideration in evaluating new drugs and devices is determining whether a product can effectively treat a targeted disease. There are quite a number of biomarkers making their way into clinical trials and few are awaiting the preclinical efficacy and safety results to enter into clinical trials. Researchers are facing challenges in modifying trial design and defining the right control population, validating biomarker assays from the bio-logical and analytical perspective and using biomarker data as a guideline for decision making. In spite of following all guidelines, the results are disappointing from many of the large clinical trials. To avoid these disappointments, selection of biomarkers and its target drug needs to be evaluated in appropriate animal models for its toxicities and efficacies. The focus of this review is on the few of the potential molecular targets and their biomarkers in colorectal cancers. Strengths and limitations of biomarkers/surrogate endpoints are also discussed. Various pathways involved in tumor cells and the specific agents to target the altered molecular biomarkerin biomolecular pathwayare elucidated. Importance of emerging new platforms siRNAs and miRNAs technology for colorectal cancer therapeutics is reviewed.

  16. Telomerase promoter mutations in cancer: an emerging molecular biomarker?

    Science.gov (United States)

    Vinagre, João; Pinto, Vasco; Celestino, Ricardo; Reis, Marta; Pópulo, Helena; Boaventura, Paula; Melo, Miguel; Catarino, Telmo; Lima, Jorge; Lopes, José Manuel; Máximo, Valdemar; Sobrinho-Simões, Manuel; Soares, Paula

    2014-08-01

    Cell immortalization has been considered for a long time as a classic hallmark of cancer cells. Besides telomerase reactivation, such immortalization could be due to telomere maintenance through the "alternative mechanism of telomere lengthening" (ALT) but the mechanisms underlying both forms of reactivation remained elusive. Mutations in the coding region of telomerase gene are very rare in the cancer setting, despite being associated with some degenerative diseases. Recently, mutations in telomerase (TERT) gene promoter were found in sporadic and familial melanoma and subsequently in several cancer models, notably in gliomas, thyroid cancer and bladder cancer. The importance of these findings has been reinforced by the association of TERT mutations in some cancer types with tumour aggressiveness and patient survival. In the first part of this review, we summarize the data on the biology of telomeres and telomerase, available methodological approaches and non-neoplastic diseases associated with telomere dysfunction. In the second part, we review the information on telomerase expression and genetic alterations in the most relevant types of cancer (skin, thyroid, bladder and central nervous system) on record, and discuss the value of telomerase as a new biomarker with impact on the prognosis and survival of the patients and as a putative therapeutic target.

  17. Molecular targeting of acid ceramidase: implications to cancer therapy.

    Science.gov (United States)

    Zeidan, Youssef H; Jenkins, Russell W; Korman, John B; Liu, Xiang; Obeid, Lina M; Norris, James S; Hannun, Yusuf A

    2008-08-01

    Increasingly recognized as bioactive molecules, sphingolipids have been studied in a variety of disease models. The impact of sphingolipids on cancer research facilitated the entry of sphingolipid analogues and enzyme modulators into clinical trials. Owing to its ability to regulate two bioactive sphingolipids, ceramide and sphingosine-1-phosphate, acid ceramidase (AC) emerges as an attractive target for drug development within the sphingolipid metabolic pathway. Indeed, there is extensive evidence supporting a pivotal role for AC in lipid metabolism and cancer biology. In this article, we review the current knowledge of the biochemical properties of AC, its relevance to tumor promotion, and its molecular targeting approaches.

  18. Growth-inhibitory Effects of Curcumin on Ovary Cancer Cells and Its Mechanisms

    Institute of Scientific and Technical Information of China (English)

    郑丽端; 童强松; 吴翠环

    2004-01-01

    Summary: To study the growth-inhibitory ettects ot curcumin on human ovary cancer A2780 cells in vitro and its molecular mechanisms, the growth inhibition rates of A2780 cancer cells, after being treated with 10 μmol/L-50 μmol/L curcumin for 6-24 h, were examined by MTT method. The morphological changes of cancer cells were observed under inversion microscopy. Cellular apoptotic rates were determined by using TUNEL. The protein expression levels of bcl-2, p53 and MDM2 in cancer cells were examined by SP immunohistochemistry. After being treated by various concentrations of curcumin, the growth of cancer cells was inhibited significantly. Some cancer cells presented characteristic morphological changes of apoptosis. The rates of apoptosis were 6.41% -28.48% (P<0.01). The expression of bcl-2 and p53 was decreased, which depended on the action time (P<0.01). There were no obvious changes in MDM2 expression. It was concluded that curcumin could significantly inhibit the growth of ovary cancer cells. The induction of apoptosis by down-regulating the expression of bcl-2 and p53 was probably one of its molecular mechanisms.

  19. 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.

  20. Molecular damage in cancer: an argument for mTOR-driven aging.

    Science.gov (United States)

    Blagosklonny, Mikhail V

    2011-12-01

    Despite common belief, accumulation of molecular damage does not play a key role in aging. Still, cancer (an age-related disease) is initiated by molecular damage. Cancer and aging share a lot in common including the activation of the TOR pathway. But the role of molecular damage distinguishes cancer and aging. Furthermore, an analysis of the role of both damage and aging in cancer argues against "a decline, caused by accumulation of molecular damage" as a cause of aging. I also discuss how random molecular damage, via rounds of multiplication and selection, brings about non-random hallmarks of cancer.

  1. Mini-review: Molecular mechanisms of antifouling compounds

    KAUST Repository

    Qian, Pei-Yuan

    2013-04-01

    Various antifouling (AF) coatings have been developed to protect submerged surfaces by deterring the settlement of the colonizing stages of fouling organisms. A review of the literature shows that effective AF compounds with specific targets are ones often considered non-toxic. Such compounds act variously on ion channels, quorum sensing systems, neurotransmitters, production/release of adhesive, and specific enzymes that regulate energy production or primary metabolism. In contrast, AF compounds with general targets may or may not act through toxic mechanisms. These compounds affect a variety of biological activities including algal photosynthesis, energy production, stress responses, genotoxic damage, immunosuppressed protein expression, oxidation, neurotransmission, surface chemistry, the formation of biofilms, and adhesive production/release. Among all the targets, adhesive production/release is the most common, possibly due to a more extensive research effort in this area. Overall, the specific molecular targets and the molecular mechanisms of most AF compounds have not been identified. Thus, the information available is insufficient to draw firm conclusions about the types of molecular targets to be used as sensitive biomarkers for future design and screening of compounds with AF potential. In this review, the relevant advantages and disadvantages of the molecular tools available for studying the molecular targets of AF compounds are highlighted briefly and the molecular mechanisms of the AF compounds, which are largely a source of speculation in the literature, are discussed. © 2013 Copyright Taylor and Francis Group, LLC.

  2. Immunophenotyping invasive breast cancer: paving the road for molecular imaging

    Directory of Open Access Journals (Sweden)

    Vermeulen Jeroen F

    2012-06-01

    Full Text Available Abstract Background Mammographic population screening in The Netherlands has increased the number of breast cancer patients with small and non-palpable breast tumors. Nevertheless, mammography is not ultimately sensitive and specific for distinct subtypes. Molecular imaging with targeted tracers might increase specificity and sensitivity of detection. Because development of new tracers is labor-intensive and costly, we searched for the smallest panel of tumor membrane markers that would allow detection of the wide spectrum of invasive breast cancers. Methods Tissue microarrays containing 483 invasive breast cancers were stained by immunohistochemistry for a selected set of membrane proteins known to be expressed in breast cancer. Results The combination of highly tumor-specific markers glucose transporter 1 (GLUT1, epidermal growth factor receptor (EGFR, insulin-like growth factor-1 receptor (IGF1-R, human epidermal growth factor receptor 2 (HER2, hepatocyte growth factor receptor (MET, and carbonic anhydrase 9 (CAIX 'detected' 45.5% of tumors, especially basal/triple negative and HER2-driven ductal cancers. Addition of markers with a 2-fold tumor-to-normal ratio increased the detection rate to 98%. Including only markers with >3 fold tumor-to-normal ratio (CD44v6 resulted in an 80% detection rate. The detection rate of the panel containing both tumor-specific and less tumor-specific markers was not dependent on age, tumor grade, tumor size, or lymph node status. Conclusions In search of the minimal panel of targeted probes needed for the highest possible detection rate, we showed that 80% of all breast cancers express at least one of a panel of membrane markers (CD44v6, GLUT1, EGFR, HER2, and IGF1-R that may therefore be suitable for molecular imaging strategies. This study thereby serves as a starting point for further development of a set of antibody-based optical tracers with a high breast cancer detection rate.

  3. MicroRNAs as molecular markers in lung cancer

    Directory of Open Access Journals (Sweden)

    Javier Silva

    2013-10-01

    Full Text Available Lung cancer is the most common cause of cancer death in the western world for both men and women. Lung cancer appears to be a perfect candidate for a screening program, since it is the number one cancer killer, it has a long preclinical phase, curative treatment for the minority of patients who are diagnosed early and a target population at risk (smokers and it is also a major economic burden. The earliest approaches to identifying cancer markers were based on preliminary clinical or pathological observations, although molecular biology is a strong candidate for occupying a place among the set of methods. In search of markers, several alterations, such as mutations, loss of heterozygosity, microsatellite instability, DNA methylation, mitochondrial DNA mutations, viral DNA, modified expression of mRNA, miRNA and proteins, and structurally altered proteins have all been analysed. MicroRNAs (miRNA are small RNA molecules, about 19-25 nucleotides long and encoded in genomes of plants, animals, fungi and viruses. It has been reported that miRNAs may have multiple functions in lung development and that aberrant expression of miRNAs could induce lung tumorigenesis. We review here the role of miRNAs in lung tumorigenesis and also as a novel type of biomarker.-----------------------------------Cite this article as:Silva J, Garcia V, Lopez-Gonzalez A, Provencio M. MicroRNAs as molecular markers in lung cancer. Int J Cancer Ther Oncol 2013;1(1:010111. DOI: http://dx.doi.org/10.14319/ijcto.0101.11

  4. Molecular deformation mechanisms of the wood cell wall material.

    Science.gov (United States)

    Jin, Kai; Qin, Zhao; Buehler, Markus J

    2015-02-01

    Wood is a biological material with outstanding mechanical properties resulting from its hierarchical structure across different scales. Although earlier work has shown that the cellular structure of wood is a key factor that renders it excellent mechanical properties at light weight, the mechanical properties of the wood cell wall material itself still needs to be understood comprehensively. The wood cell wall material features a fiber reinforced composite structure, where cellulose fibrils act as stiff fibers, and hemicellulose and lignin molecules act as soft matrix. The angle between the fiber direction and the loading direction has been found to be the key factor controlling the mechanical properties. However, how the interactions between theses constitutive molecules contribute to the overall properties is still unclear, although the shearing between fibers has been proposed as a primary deformation mechanism. Here we report a molecular model of the wood cell wall material with atomistic resolution, used to assess the mechanical behavior under shear loading in order to understand the deformation mechanisms at the molecular level. The model includes an explicit description of cellulose crystals, hemicellulose, as well as lignin molecules arranged in a layered nanocomposite. The results obtained using this model show that the wood cell wall material under shear loading deforms in an elastic and then plastic manner. The plastic regime can be divided into two parts according to the different deformation mechanisms: yielding of the matrix and sliding of matrix along the cellulose surface. Our molecular dynamics study provides insights of the mechanical behavior of wood cell wall material at the molecular level, and paves a way for the multi-scale understanding of the mechanical properties of wood.

  5. Reaction Mechanism of Mycobacterium Tuberculosis Glutamine Synthetase Using Quantum Mechanics/Molecular Mechanics Calculations.

    Science.gov (United States)

    Moreira, Cátia; Ramos, Maria J; Fernandes, Pedro Alexandrino

    2016-06-27

    This paper is devoted to the understanding of the reaction mechanism of mycobacterium tuberculosis glutamine synthetase (mtGS) with atomic detail, using computational quantum mechanics/molecular mechanics (QM/MM) methods at the ONIOM M06-D3/6-311++G(2d,2p):ff99SB//B3LYP/6-31G(d):ff99SB level of theory. The complete reaction undergoes a three-step mechanism: the spontaneous transfer of phosphate from ATP to glutamate upon ammonium binding (ammonium quickly loses a proton to Asp54), the attack of ammonia on phosphorylated glutamate (yielding protonated glutamine), and the deprotonation of glutamine by the leaving phosphate. This exothermic reaction has an activation free energy of 21.5 kcal mol(-1) , which is consistent with that described for Escherichia coli glutamine synthetase (15-17 kcal mol(-1) ). The participating active site residues have been identified and their role and energy contributions clarified. This study provides an insightful atomic description of the biosynthetic reaction that takes place in this enzyme, opening doors for more accurate studies for developing new anti-tuberculosis therapies.

  6. Platinum drugs and DNA repair mechanisms in lung cancer.

    Science.gov (United States)

    Bonanno, Laura; Favaretto, Adolfo; Rosell, Rafael

    2014-01-01

    The standard first-line treatment for around 80% of newly-diagnosed advanced non-small cell lung cancer (NSCLC) is chemotherapy. Currently, patients are allocated to chemotherapy on the basis of clinical conditions, comorbidities and histology. If feasible, platinum-based chemotherapy is considered as the most efficacious option. Due to the heterogeneity in terms of platinum-sensitivity among patients with NSCLC, great efforts have been made in order to identify molecular predictive markers of platinum resistance. Based on the mechanism of action of platinum, several components of DNA repair pathways have been investigated as potential predictive markers. The main DNA repair pathways involved in the repair of platinum-induced DNA damage are nucleotide excision repair and homologous recombination. The most studied potential predictive markers of platinum-sensitivity are Excision Repair Cross Complementing-1 (ERCC1) and Brest Cancer Type-I Susceptibility protein (BRCA1); however, increasing biological knowledge about DNA repair pathways suggests the potential clinical usefulness of integrated analysis of multiple DNA repair components.

  7. Molecular targeted therapy in the treatment of advanced stage non-small cell lung cancer (NSCLC).

    Science.gov (United States)

    Kumarakulasinghe, Nesaretnam Barr; van Zanwijk, Nico; Soo, Ross A

    2015-04-01

    Historically, patients with advanced stage non-small cell lung cancer (NSCLC) were treated with chemotherapy alone, but a therapeutic plateau has been reached. Advances in the understanding of molecular genetics have led to the recognition of multiple molecularly distinct subsets of NSCLC. This in turn has led to the development of rationally directed molecular targeted therapy, leading to improved clinical outcomes. Tumour genotyping for EGFR mutations and ALK rearrangement has meant chemotherapy is no longer given automatically as first-line treatment but reserved for when patients do not have a 'druggable' driver oncogene. In this review, we will address the current status of clinically relevant driver mutations and emerging new molecular subsets in lung adenocarcinoma and squamous cell carcinoma, and the role of targeted therapy and mechanisms of acquired resistance to targeted therapy.

  8. Alcohol and breast cancer: reconciling epidemiological and molecular data.

    Science.gov (United States)

    Zakhari, Samir; Hoek, Jan B

    2015-01-01

    Breast cancer is the most diagnosed cancer in women worldwide. Epidemiological studies have suggested a possible causative role of alcohol consumption as a risk factor for breast cancer. However, such conclusions should be interpreted with considerable caution for several reasons. While epidemiological studies can help identify the roots of health problems and disease incidence in a community, they are by necessity associative and cannot determine cause and effect relationships. In addition, all these studies rely on self-reporting to determine the amount and type of alcoholic beverage consumed, which introduces recall bias. This is documented in a recent study which stated that the apparent increased risk of cancer among light-moderate drinkers may be "substantially due to underreporting of intake." Another meta-analysis about alcohol and breast cancer declared "the modest size of the association and variation in results across studies leave the causal role of alcohol in question." Furthermore, breast cancer develops over decades; thus, correlations between alcohol consumption and breast cancer cannot be determined in epidemiological studies with windows of alcohol exposure that captures current or recent alcohol intake, after clinical diagnosis. Numerous risk factors are involved in breast carcinogenesis; some are genetic and beyond the control of a woman; others are influenced by lifestyle factors. Breast cancer is a heterogeneous and polygenic disease which is further influenced by epigenetic mechanisms that affect the transciptomes, proteomes and metabolomes, and ultimately breast cancer evolution. Environmental factors add another layer of complexity by their interactions with the susceptibility genes for breast cancer and metabolic diseases. The current state-of-knowledge about alcohol and breast cancer association is ambiguous and confusing to both a woman and her physician. Confronting the huge global breast cancer issue should be addressed by sound

  9. Molecular epidemiology, cancer-related symptoms, and cytokines pathway.

    Science.gov (United States)

    Reyes-Gibby, Cielito C; Wu, Xifeng; Spitz, Margaret; Kurzrock, Razelle; Fisch, Michael; Bruera, Eduardo; Shete, Sanjay

    2008-08-01

    The Human Genome Project and HapMap have led to a better appreciation of the importance of common genetic variation in determining cancer risk, created potential for predicting response to therapy, and made possible the development of targeted prevention and therapeutic interventions. Advances in molecular epidemiology can be used to explore the role of genetic variation in modulating the risk for severe and persistent symptoms, such as pain, depression, and fatigue, in patients with cancer. The same genes that are implicated in cancer risk might also be involved in the modulation of therapeutic outcomes. For example, polymorphisms in several cytokine genes are potential markers for genetic susceptibility both for cancer risk and for cancer-related symptoms. These genetic polymorphisms are stable markers and easily and reliably assayed to explore the extent to which genetic variation might prove useful in identifying patients with cancer at high-risk of symptom development. Likewise, they could identify subgroups who might benefit most from symptom intervention, and contribute to developing personalized and more effective therapies for persistent symptoms.

  10. AN EPIDEMIOLOGY AND MOLECULAR GENETIC STUDY ON BREAST CANCER SUSCEPTIBILITY

    Institute of Scientific and Technical Information of China (English)

    贾卫华; 王继先; 李本孝; 李征

    2000-01-01

    Objectives. To investigate the genetic susceptibility for breast cancer of Chinese, a hospital-based case-control study, pedigree survey and molecular genetic study were conducted. Methods. Logistic regression model and stratification methods were used in the risk factors analysis. Li-Mantel art and Falconer methods were used to analyze the segregation ratio and heritability. Polymerase chain reaction (PCR) and polyacrylamide gel electrophoresis were used to detect AI, G-banding technique was used to detect the chromosome aberration of peripheral blood lymphocyte. Results. Family history of breast cancer is related to enhanced breast cancer risk significartly, OR is 3.905 ( 95 % CI = 1.079 ~ 14.13), and it widely interacts with other risk factors. Accumulative incidence of breast cancer in first degree relatives is 9.99%, which is larger than that in second, third degree and non-blood relatives. Segregation ratio is 0.021, heritability among first degree relatives is 35.6 ± 5.8%. Frequencies of LOH at BRCA1 and BRCA2 loci in sporadic breast cancer are 6.12% and 5.77% respectively. In the sibs, both of them show LOH at D13S173 locus, and high frequencies of chromosome aberrations were observed. Conclusions. Genetic susceptibility contributes to breast cancer occurrence of Chinese, and its racial variation may be one of the important reasons for the large difference of incidence between western and eastern countries.

  11. AN EPIDEMIOLOGY AND MOLECULAR GENETIC STUDY ON BREAST CANCER SUSCEPTIBILITY

    Institute of Scientific and Technical Information of China (English)

    贾卫华; 王继先; 李本孝; 李征

    2000-01-01

    Obieaites. To investigate the genetic susceptibility for breast cancer of Chinese, a hospital-besed case-control study, pedigree survey and molecular genetic study were conducted. Methods. Logistic regression model and stratification methods were used in the risk factors analysis. Li-Mantel-Gart and Falconer methods were used to analyze the segregation ratio and heritability. Polymemse chain reaction (PCR) and polyacrylamide gel electrophoresis were used to detect AI, G-banding technique was used to detect the chromosome aberration of peripheral blood lymphocyte. Results. Family history of breast cancer is related to enhanced breast cancer risk significantly, OR is 3.905(95% CI = 1.079—14.13), and it widely interacts with other risk factors. Accumulative incidence of breast cancer in first degree relatives is 9.99%, which is larger than that in second, third degree and non-blnod relatives. Segregation ratio is 0.021, heritability among first degree relatives is 35.6 ± 5.8%. Frequencies of LDH at BRCA1 and BRCA2 loci in sporadic breast cancer are 6.12% and 5.77% respectively. In the sibs, both of them show LOH at D13S173 locus, and high frequencies of chromosome abermtions were observed.Condusions. Genetic susceptibility contributes to breast cancer occurrence of Chinese, and its racial variation may be one of the important reasons for the large difference of incidence between western and eastern countries.

  12. Chemopreventive potential of chlorophyllin: a review of the mechanisms of action and molecular targets.

    Science.gov (United States)

    Nagini, Siddavaram; Palitti, Fabrizio; Natarajan, Adayapalam T

    2015-01-01

    Chlorophyllin (CHL), a water soluble semisynthetic derivative of the ubiquitous plant pigment chlorophyll used as a food additive, is recognized to confer a wide range of health benefits. CHL has been shown to exhibit potent antigenotoxic, anti-oxidant, and anticancer effects. Numerous experimental and epidemiological studies have demonstrated that dietary supple-mentation of CHL lowers the risk of cancer. CHL inhibits cancer initiation and progression by targeting multiple molecules and pathways involved in the metabolism of carcinogens, cell cycle progression, apoptosis evasion, invasion, and angiogenesis. The modulatory effects of CHL on the hallmark capabilities of cancer appear to be mediated via abrogation of key oncogenic signal transduction pathways such as nuclear factor kappa B, Wnt/β-catenin, and phosphatidylinositol-3-kinase/Akt signaling. This review provides insights into the molecular mechanisms of the anticancer effects of dietary CHL.

  13. Probing molecular mechanisms of the Hsp90 chaperone: biophysical modeling identifies key regulators of functional dynamics.

    Directory of Open Access Journals (Sweden)

    Anshuman Dixit

    Full Text Available Deciphering functional mechanisms of the Hsp90 chaperone machinery is an important objective in cancer biology aiming to facilitate discovery of targeted anti-cancer therapies. Despite significant advances in understanding structure and function of molecular chaperones, organizing molecular principles that control the relationship between conformational diversity and functional mechanisms of the Hsp90 activity lack a sufficient quantitative characterization. We combined molecular dynamics simulations, principal component analysis, the energy landscape model and structure-functional analysis of Hsp90 regulatory interactions to systematically investigate functional dynamics of the molecular chaperone. This approach has identified a network of conserved regions common to the Hsp90 chaperones that could play a universal role in coordinating functional dynamics, principal collective motions and allosteric signaling of Hsp90. We have found that these functional motifs may be utilized by the molecular chaperone machinery to act collectively as central regulators of Hsp90 dynamics and activity, including the inter-domain communications, control of ATP hydrolysis, and protein client binding. These findings have provided support to a long-standing assertion that allosteric regulation and catalysis may have emerged via common evolutionary routes. The interaction networks regulating functional motions of Hsp90 may be determined by the inherent structural architecture of the molecular chaperone. At the same time, the thermodynamics-based "conformational selection" of functional states is likely to be activated based on the nature of the binding partner. This mechanistic model of Hsp90 dynamics and function is consistent with the notion that allosteric networks orchestrating cooperative protein motions can be formed by evolutionary conserved and sparsely connected residue clusters. Hence, allosteric signaling through a small network of distantly connected

  14. Breast cancer: mechanisms involved in action of phytoestrogens and epigenetic changes.

    Science.gov (United States)

    Dagdemir, Aslihan; Durif, Julie; Ngollo, Marjolaine; Bignon, Yves-Jean; Bernard-Gallon, Dominique

    2013-01-01

    In this review, we consider phytoestrogens and different epigenetic modifications in breast cancer. Epigenetic phenomena are mediated by several molecular mechanisms comprising histone modifications, small non-coding or anti-sense RNA and DNA methylation. These different modifications are closely interrelated. De-regulation of gene expression is a hallmark of cancer. Although genetic lesions have been the focus of cancer research for many years, it has become increasingly recognized that aberrant epigenetic modifications also play major roles in breast carcinogenesis. The incidence and mortality rates of breast cancer are high in the Western world compared with countries in Asia. There are also differences in the breast cancer incidence rates in different Western countries. This could be related to phytoestrogens.

  15. Roles of Ubiquitination and SUMOylation on Prostate Cancer: Mechanisms and Clinical Implications

    Directory of Open Access Journals (Sweden)

    Zhenbang Chen

    2015-02-01

    Full Text Available The initiation and progression of human prostate cancer are highly associated with aberrant dysregulations of tumor suppressors and proto-oncogenes. Despite that deletions and mutations of tumor suppressors and aberrant elevations of oncogenes at the genetic level are reported to cause cancers, emerging evidence has revealed that cancer progression is largely regulated by posttranslational modifications (PTMs and epigenetic alterations. PTMs play critical roles in gene regulation, cellular functions, tissue development, diseases, malignant progression and drug resistance. Recent discoveries demonstrate that ubiquitination and SUMOylation are complicated but highly-regulated PTMs, and make essential contributions to diseases and cancers by regulation of key factors and signaling pathways. Ubiquitination and SUMOylation pathways can be differentially modulated under various stimuli or stresses in order to produce the sustained oncogenic potentials. In this review, we discuss some new insights about molecular mechanisms on ubiquitination and SUMOylation, their associations with diseases, oncogenic impact on prostate cancer (PCa and clinical implications for PCa treatment.

  16. Green tea catechins: Proposed mechanisms of action in breast cancer focusing on the interplay between survival and apoptosis.

    Science.gov (United States)

    Yiannakopoulou, Eugenia Ch

    2014-02-01

    Recent data have shown strong chemopreventive and possibly cancer chemotherapeutic effects of green tea polyphenols against cancer. Despite advances in breast cancer treatment, mortality from breast cancer is still high. Undoubtedly novel treatment strategies are needed for chemoprevention of high risk women and for the treatment of receptor negative breast cancer. Green tea catechins have been shown to inhibit proliferation of breast cancer cells and to block carcinogenesis. This review attempts a critical presentation of the mechanisms of action of green tea catechins in breast cancer. Several mechanisms of action of green tea catechins in breast cancer have been proposed including modulation of extracellular signalling, induction of apoptosis through redox regulation, or through modulation of epigenetic alterations. A number of molecular targets of green tea catechins have been suggested i.e molecular chaperones, telomerase, apoptotic cascade. Although the molecular links among the proposed mechanisms of action of green tea catechins are often missing, it must be emphasized that all the proposed mechanisms indicate that green tea catechins inhibit growth and /or promote apoptosis. It would be interesting if future experimental trials could take into account that green tea catechins are multi-target agents and attempt to link every novel proposed target with the other already proposed targets of green tea catechins.

  17. Clinical implications of the intrinsic molecular subtypes of breast cancer.

    Science.gov (United States)

    Prat, Aleix; Pineda, Estela; Adamo, Barbara; Galván, Patricia; Fernández, Aranzazu; Gaba, Lydia; Díez, Marc; Viladot, Margarita; Arance, Ana; Muñoz, Montserrat

    2015-11-01

    Gene-expression profiling has had a considerable impact on our understanding of breast cancer biology. During the last 15 years, 5 intrinsic molecular subtypes of breast cancer (Luminal A, Luminal B, HER2-enriched, Basal-like and Claudin-low) have been identified and intensively studied. In this review, we will focus on the current and future clinical implications of the intrinsic molecular subtypes beyond the current pathological-based classification endorsed by the 2013 St. Gallen Consensus Recommendations. Within hormone receptor-positive and HER2-negative early breast cancer, the Luminal A and B subtypes predict 10-year outcome regardless of systemic treatment administered as well as residual risk of distant recurrence after 5 years of endocrine therapy. Within clinically HER2-positive disease, the 4 main intrinsic subtypes can be identified and dominate the biological and clinical phenotype. From a clinical perspective, patients with HER2+/HER2-enriched disease seem to benefit the most from neoadjuvant trastuzumab, or dual HER2 blockade with trastuzumab/lapatinib, in combination with chemotherapy, and patients with HER2+/Luminal A disease seem to have a relative better outcome compared to the other subtypes. Finally, within triple-negative breast cancer (TNBC), the Basal-like disease predominates (70-80%) and, from a biological perspective, should be considered a cancer-type by itself. Importantly, the distinction between Basal-like versus non-Basal-like within TNBC might predict survival following (neo)adjvuvant multi-agent chemotherapy, bevacizumab benefit in the neoadjuvant setting (CALGB40603), and docetaxel vs. carboplatin benefit in first-line metastatic disease (TNT study). Overall, this data suggests that intrinsic molecular profiling provides clinically relevant information beyond current pathology-based classifications.

  18. Molecular Targeted Approaches to Cancer Therapy and Prevention Using Chalcones

    OpenAIRE

    Jandial, Danielle D.; Blair, Christopher A.; Zhang, Saiyang; Krill, Lauren S; Zhang, Yan-Bing; Zi, Xiaolin

    2014-01-01

    There is an emerging paradigm shift in oncology that seeks to emphasize molecularly targeted approaches for cancer prevention and therapy. Chalcones (1,3-diphenyl-2-propen-1-ones), naturally-occurring compounds with widespread distribution in spices, tea, beer, fruits and vegetables, consist of open-chain flavonoids in which the two aromatic rings are joined by a three-carbon α, β-unsaturated carbonyl system. Due to their structural diversity, relative ease of chemical manipulation and reacti...

  19. Molecular characterization of the stomach microbiota in patients with gastric cancer and controls

    Energy Technology Data Exchange (ETDEWEB)

    Dicksved, J.; Lindberg, M.; Rosenquist, M.; Enroth, H.; Jansson, J.K.; Engstrand, L.

    2009-01-15

    Persistent infection of the gastric mucosa by Helicobacter pylori, can initiate an inflammatory cascade that progresses into atrophic gastritis, a condition associated with reduced capacity for secretion of gastric acid and an increased risk in developing gastric cancer. The role of H. pylori as an initiator of inflammation is evident but the mechanism for development into gastric cancer has not yet been proven. A reduced capacity for gastric acid secretion allows survival and proliferation of other microbes that normally are killed by the acidic environment. It has been postulated that some of these species may be involved in the development of gastric cancer, however their identities are poorly defined. In this study, the gastric microbiota from ten patients with gastric cancer was characterized and compared with five dyspeptic controls using the molecular profiling approach, terminal-restriction fragment length polymorphism (T-RFLP), in combination with 16S rRNA gene cloning and sequencing. T-RFLP analysis revealed a complex bacterial community in the cancer patients that was not significantly different from the controls. Sequencing of 140 clones revealed 102 phylotypes, with representatives from five bacterial phyla (Firmicutes, Bacteroidetes, Proteobacteria, Actinobacteria and Fusobacteria). The data revealed a relatively low abundance of H. pylori and showed that the gastric cancer microbiota was instead dominated by different species of the genera Streptococcus, Lactobacillus, Veillonella and Prevotella. The respective role of these species in development of gastric cancer remains to be determined.

  20. Status and Advances of RGD Molecular Imaging in Lung Cancer

    Directory of Open Access Journals (Sweden)

    Ning YUE

    2014-12-01

    Full Text Available Lung cancer has been one of the most common and the highest mortality rates malignant tumors at home and abroad. Sustained angiogenesis was not only the characteristic of malignant tumors, but also the foundation of tumor proliferation, invasion, recurrence and metastasis, it was also one of the hot spots of treatments in lung cancer biology currently. Integrins played an important part in tumor angiogenesis. Arg-Gly-Asp (RGD peptides could combine with integrins specifically, and the application of radionuclide-labeled RGD molecular probes enabled imaging of tumor blood vessels to reflect its changes. The lung cancer imaging of RGD peptides at home and abroad in recent years was reviewed in this article.

  1. Multifunctional Gold Nanostars for Molecular Imaging and Cancer Therapy

    Science.gov (United States)

    Liu, Yang; Yuan, Hsiangkuo; Fales, Andrew; Register, Janna; Vo-Dinh, Tuan

    2015-08-01

    Plasmonics-active gold nanoparticles offer excellent potential in molecular imaging and cancer therapy. Among them, gold nanostars (AuNS) exhibit cross-platform flexibility as multimodal contrast agents for macroscopic X-ray computer tomography (CT), magnetic resonance imaging (MRI), positron emission tomography (PET), as well as nanoprobes for photoacoustic tomography (PAT), two-photon photoluminescence (TPL) and surface-enhanced Raman spectroscopy (SERS). Their surfactant-free surface enables versatile functionalization to enhance cancer targeting, and allow triggered drug release. AuNS can also be used as an efficient platform for drug carrying, photothermal therapy, and photodynamic therapy. This review paper presents the latest progress regarding AuNS as a promising nanoplatform for cancer nanotheranostics. Future research directions with AuNS for biomedical applications will also be discussed.

  2. Multifunctional Gold Nanostars for Molecular Imaging and Cancer Therapy

    Directory of Open Access Journals (Sweden)

    Yang eLiu

    2015-08-01

    Full Text Available Plasmonics-active gold nanoparticles offer excellent potential in molecular imaging and cancer therapy. Among them, gold nanostars (AuNS exhibit cross-platform flexibility as multimodal contrast agents for macroscopic X-ray computer tomography (CT, magnetic resonance imaging (MRI, positron emission tomography (PET, as well as nanoprobes for photoacoustic tomography (PAT, two-photon photoluminescence (TPL and surface-enhanced Raman spectroscopy (SERS. Their surfactant-free surface enables versatile functionalization to enhance cancer targeting, and allow triggered drug release. AuNS can also be used as an efficient platform for drug carrying, photothermal therapy, and photodynamic therapy. This review paper presents the latest progress regarding AuNS as a promising nanoplatform for cancer nanotheranostics. Future research directions with AuNS for biomedical applications will also be discussed.

  3. Molecular mechanisms controlling the cell cycle in embryonic stem cells.

    Science.gov (United States)

    Abdelalim, Essam M

    2013-12-01

    Embryonic stem (ES) cells are originated from the inner cell mass of a blastocyst stage embryo. They can proliferate indefinitely, maintain an undifferentiated state (self-renewal), and differentiate into any cell type (pluripotency). ES cells have an unusual cell cycle structure, consists mainly of S phase cells, a short G1 phase and absence of G1/S checkpoint. Cell division and cell cycle progression are controlled by mechanisms ensuring the accurate transmission of genetic information from generation to generation. Therefore, control of cell cycle is a complicated process, involving several signaling pathways. Although great progress has been made on the molecular mechanisms involved in the regulation of ES cell cycle, many regulatory mechanisms remain unknown. This review summarizes the current knowledge about the molecular mechanisms regulating the cell cycle of ES cells and describes the relationship existing between cell cycle progression and the self-renewal.

  4. Molecular Classification of Gastric Cancer: A new paradigm

    Science.gov (United States)

    Shah, Manish A.; Khanin, Raya; Tang, Laura; Janjigian, Yelena Y.; Klimstra, David S.; Gerdes, Hans; Kelsen, David P.

    2011-01-01

    Purpose Gastric cancer may be subdivided into three distinct subtypes –proximal, diffuse, and distal gastric cancer– based on histopathologic and anatomic criteria. Each subtype is associated with unique epidemiology. Our aim is to test the hypothesis that these distinct gastric cancer subtypes may also be distinguished by gene expression analysis. Experimental Design Patients with localized gastric adenocarcinoma being screened for a phase II preoperative clinical trial (NCI 5917) underwent endoscopic biopsy for fresh tumor procurement. 4–6 targeted biopsies of the primary tumor were obtained. Macrodissection was performed to ensure >80% carcinoma in the sample. HG-U133A GeneChip (Affymetrix) was used for cDNA expression analysis, and all arrays were processed and analyzed using the Bioconductor R-package. Results Between November 2003 and January 2006, 57 patients were screened to identify 36 patients with localized gastric cancer who had adequate RNA for expression analysis. Using supervised analysis, we built a classifier to distinguish the three gastric cancer subtypes, successfully classifying each into tightly grouped clusters. Leave-one-out cross validation error was 0.14, suggesting that >85% of samples were classified correctly. Gene set analysis with the False Discovery Rate set at 0.25 identified several pathways that were differentially regulated when comparing each gastric cancer subtype to adjacent normal stomach. Conclusions Subtypes of gastric cancer that have epidemiologic and histologic distinction are also distinguished by gene expression data. These preliminary data suggest a new classification of gastric cancer with implications for improving our understanding of disease biology and identification of unique molecular drivers for each gastric cancer subtype. PMID:21430069

  5. Molecular imaging of prostate cancer: translating molecular biology approaches into the clinical realm

    Energy Technology Data Exchange (ETDEWEB)

    Vargas, Hebert Alberto; Sala, Evis; Hricak, Hedvig [Memorial Sloan Kettering Cancer Center, Department of Radiology, New York, NY (United States); Grimm, Jan [Memorial Sloan Kettering Cancer Center, Department of Radiology, New York, NY (United States); Program in Molecular Pharmacology and Chemistry, Memorial Sloan Kettering Cancer Center, New York (United States); Donati, Olivio F. [Memorial Sloan Kettering Cancer Center, Department of Radiology, New York, NY (United States); University Hospital Zurich, Institute of Diagnostic and Interventional Radiology, Zurich (Switzerland)

    2015-05-01

    The epidemiology of prostate cancer has dramatically changed since the introduction of prostate-specific antigen (PSA) screening in the 1980's. Most prostate cancers today are detected at early stages of the disease and are considered 'indolent'; however, some patients' prostate cancers demonstrate a more aggressive behaviour which leads to rapid progression and death. Increasing understanding of the biology underlying the heterogeneity that characterises this disease has led to a continuously evolving role of imaging in the management of prostate cancer. Functional and metabolic imaging techniques are gaining importance as the impact on the therapeutic paradigm has shifted from structural tumour detection alone to distinguishing patients with indolent tumours that can be managed conservatively (e.g., by active surveillance) from patients with more aggressive tumours that may require definitive treatment with surgery or radiation. In this review, we discuss advanced imaging techniques that allow direct visualisation of molecular interactions relevant to prostate cancer and their potential for translation to the clinical setting in the near future. The potential use of imaging to follow molecular events during drug therapy as well as the use of imaging agents for therapeutic purposes will also be discussed. (orig.)

  6. Wilson's disease: a comprehensive review of the molecular mechanisms.

    Science.gov (United States)

    Wu, Fei; Wang, Jing; Pu, Chunwen; Qiao, Liang; Jiang, Chunmeng

    2015-01-01

    Wilson's disease (WD), also known as hepatolenticular degeneration, is an autosomal recessive inherited disorder resulting from abnormal copper metabolism. Reduced copper excretion causes an excessive deposition of the copper in many organs such as the liver, central nervous system (CNS), cornea, kidney, joints, and cardiac muscle where the physiological functions of the affected organs are impaired. The underlying molecular mechanisms for WD have been extensively studied. It is now believed that a defect in P-type adenosine triphosphatase (ATP7B), the gene encoding the copper transporting P-type ATPase, is responsible for hepatic copper accumulation. Deposited copper in the liver produces toxic effects via modulating several molecular pathways. WD can be a lethal disease if left untreated. A better understanding of the molecular mechanisms causing the aberrant copper deposition and organ damage is the key to developing effective management approaches.

  7. Molecular basis of the potential of mesalazine to prevent colorectal cancer

    Institute of Scientific and Technical Information of China (English)

    Carmine Stolfi; Roberto Pellegrini; Eleonora Franzè; Francesco Pallone; Giovanni Monteleone

    2008-01-01

    Patients with ulcerative colitis (UC) and Crohn's disease (CD) are at increased risk for developing colorectal cancer (CRC), and this is believed to be a result of chronic inflammation. Although conclusive evidence is still missing, both epidemiological and experimental observations suggest that certain drugs used to treat inflammation, such as mesalazine,can reduce the incidence of colitis-associated CRC.Therefore, in recent years, several studies have been conducted to dissect the mechanisms by which mesalazine interferes with CRC cell growth and survival. This review summarizes the current information on the molecular mechanisms that underlie the antineoplastic action of mesalazine.

  8. Molecular mechanisms in muscular dystrophy : a gene expression profiling study.

    NARCIS (Netherlands)

    Turk, Rolf

    2006-01-01

    The muscular dystrophies are a group of neuromuscular disorders characterized by progres¬sive muscle weakness and wasting. Although the underlying genetic defects of a large number of muscular dystrophies are now know, the molecular mechanisms resulting in the devastating effects of the disease are

  9. Molecular mechanisms of novel regulators in cytokine signal transduction

    NARCIS (Netherlands)

    Xiaofei, Zhang

    2013-01-01

    By identifying and studying novel regulators, the studies described in this thesis give substantive insights into the molecular mechanisms and different levels of control of TGF-β/BMP, IL-1β and Wnt signaling pathways. Crucially, our work for the first time demonstrated the monoubiquitination of an

  10. Predictive and prognostic molecular markers for cancer medicine.

    Science.gov (United States)

    Mehta, Sunali; Shelling, Andrew; Muthukaruppan, Anita; Lasham, Annette; Blenkiron, Cherie; Laking, George; Print, Cristin

    2010-03-01

    Over the last 10 years there has been an explosion of information about the molecular biology of cancer. A challenge in oncology is to translate this information into advances in patient care. While there are well-formed routes for translating new molecular information into drug therapy, the routes for translating new information into sensitive and specific diagnostic, prognostic and predictive tests are still being developed. Similarly, the science of using tumor molecular profiles to select clinical trial participants or to optimize therapy for individual patients is still in its infancy. This review will summarize the current technologies for predicting treatment response and prognosis in cancer medicine, and outline what the future may hold. It will also highlight the potential importance of methods that can integrate molecular, histopathological and clinical information into a synergistic understanding of tumor progression. While these possibilities are without doubt exciting, significant challenges remain if we are to implement them with a strong evidence base in a widely available and cost-effective manner.

  11. Molecular Biology and Prevention of Endometrial Cancer. Addendum

    Science.gov (United States)

    2008-07-01

    gain insight into the biologic mechanism underlying the chemopreventive effect of the oral contraceptive pill (OCP). Project 1: Objectives completed...oral contraceptive pill and hormone replacement therapy on reproductive organs. This objective has been completed and the results were submitted...protective effect of oral contraceptive (OC) therapy. Methods: 1) Oligonucleotide microarray analysis was performed on a panel of endometrial cancers

  12. Molecular subtypes and imaging phenotypes of breast cancer

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Nariya [Dept. of Radiology, Seoul National University Hospital, Seoul (Korea, Republic of)

    2016-08-15

    During the last 15 years, traditional breast cancer classifications based on histopathology have been reorganized into the luminal A, luminal B, human epidermal growth factor receptor 2 (HER2), and basal-like subtypes based on gene expression profiling. Each molecular subtype has shown varying risk for progression, response to treatment, and survival outcomes. Research linking the imaging phenotype with the molecular subtype has revealed that non-calcified, relatively circumscribed masses with posterior acoustic enhancement are common in the basal-like subtype, spiculated masses with a poorly circumscribed margin and posterior acoustic shadowing in the luminal subtype, and pleomorphic calcifications in the HER2-enriched subtype. Understanding the clinical implications of the molecular subtypes and imaging phenotypes could help radiologists guide precision medicine, tailoring medical treatment to patients and their tumor characteristics.

  13. [Molecular-targeted therapy for hormone-refractory prostate cancer].

    Science.gov (United States)

    Nishimura, Kazuo; Takayama, Hitoshi; Nakayama, Masashi; Nonomura, Norio; Okuyama, Akihiko

    2006-06-01

    Molecular-targeted therapy is to treat pathologic pathways specifically in tumor cell or tumor microenvironment. Specific molecular-targeted therapeutic agents for hormone-refractory prostate cancer (HRPC) include endothelin-A receptor antagonist, EGF receptor (EGFR) inhibitor, platelet derived growth factor receptor (PDGFR) inhibitor, nuclear factor of kappaB (NF-kappaB) inhibitor, cyclooxygenase-2 (COX2) inhibitor, and active form of Vitamin D. These agents have been investigated in clinical trials. So far, none of the above-mentioned agent has shown a sufficient clinical efficacy alone. However, docetaxel-based combinations with thalidomide or calcitriol have promising clinical activities. Further investigations are needed to optimize the molecular-targeted agents in the combinations with chemotherapeutic agents for the treatment of HRPC.

  14. Mechanisms of CTC Biomarkers in Breast Cancer Brain Metastasis

    Science.gov (United States)

    2015-10-01

    represents the most devastating and feared consequence of breast cancer . BCBM is usually fatal and is increasing in frequency with occult brain...metastatic breast cancer (stage IV) patients with or without clinically diagnosed BCBM employing multiparametric flow cytometry (FACS; ARIA IIID system)(10...AWARD NUMBER: W81XWH-14-1-0214 TITLE: Mechanisms of CTC Biomarkers in Breast Cancer Brain Metastasis PRINCIPAL INVESTIGATOR: Dario

  15. Molecular targets of cancer chemoprevention by garlic-derived organosulfides

    Institute of Scientific and Technical Information of China (English)

    Anna HERMAN-ANTOSIEWICZ; Anna A POWOLNY; Shivendra V SINGH

    2007-01-01

    The medicinal benefits of Allium vegetables, especially garlic, have been noted throughout recorded history. The known health benefits of Allium vegetables and their constituents include cardiovascular protective effects, stimulation of immune function, reduction of blood glucose level, radioprotection, improvement of memory loss, protection against microbial, viral and fungal infections, as well as anticancer effects. Population-based case control studies have suggested an inverse correlation between dietary intake of Allium vegetables and the risk of different types of cancers. The anticarcinogenic effect of Allium vegetables in-eluding garlic is attributed to organosulfur compounds (OSC), which are highly effective in affording protection against cancer in animal models induced by a variety of chemical carcinogens. More recent studies have shown that certain naturally occurring OSC analogues can suppress proliferation of cancer cells in culture and in vivo. The OSC-induced changes in the proliferation of cancer Cellsare frequently associated with perturbations in cell cycle progression and induc-tion of G2/M phase arrest. The OSC have also been demonstrated to induce apoptosis via the intrinsic pathway by altering the ratio of the Bc1-2 family of proteins both in cell culture and in in vivo models. Anti-angiogenic activity for garlic-derived OSC has also been documented. This article summarizes current knowledge on molecular targets of cancer chemoprevention by OSC.

  16. Xenogeneic homologous genes, molecular evolution and cancer therapy

    Institute of Scientific and Technical Information of China (English)

    田聆; 魏于全

    2001-01-01

    Cancer is one of the main causes for death of human beings to date, and cancer biotherapy (mainlyimmunotherapy and gene therapy) has become the most promising approach after surgical therapy, radiotherapy andchemotherapy. However, there are still many limitations on cancer immunotherapy and gene therapy; therefore great ef-fort is being made to develop new strategies. It has been known that, in the process of evolution, a number of genes, theso-called xenogeneic homologous genes, are well-conserved and show the structural and/or functional similarity betweenvarious species to some degree. The nucleotide changes between various xenogeneic homologous genes are derived frommutation, and most of them are neutral mutations. Considering that the subtle differences in xenogeneic homologousgenes can break immune tolerance, enhance the immunogenicity and induce autologous immune response so as to elimi-nate tumor cells, we expect that a strategy of inducing autoimmune response using the property of xenogeneic homologousgenes will become a new therapy for cancer. Moreover, this therapy can also be used in the treatment of other diseases,such as autoimmune diseases and AIDS. This article will discuss the xenogeneic homologous genes, molecular evolutionand cancer therapy.

  17. Molecular cytogenetic applications in analysis of the cancer genome.

    Science.gov (United States)

    Rao, Pulivarthi H; Nandula, Subhadra V; Murty, Vundavalli V

    2007-01-01

    Cancer cells exhibit nonrandom and complex chromosome abnormalities. The role of genomic changes in cancer is well established. However, the identification of complex and cryptic chromosomal changes is beyond the resolution of conventional banding methods. The fluorescence microscopy afforded by imaging technologies, developed recently, facilitates a precise identification of these chromosome alterations in cancer. The three most commonly utilized molecular cytogenetics methods comparative genomic hybridization, spectral karyotype, and fluorescence in situ hybridization, that have already become benchmark tools in cancer cytogenetics, are described in this chapter. Comparative genomic hybridization is a powerful tool for screening copy-number changes in tumor genomes without the need for preparation of metaphases from tumor cells. Multicolor spectral karyotype permits visualization of all chromosomes in one experiment permitting identification of precise chromosomal changes on metaphases derived from tumor cells. The uses of fluorescence in situ hybridization are diverse, including mapping of alteration in single copy genes, chromosomal regions, or entire chromosomes. The opportunities to detect genetic alterations in cancer cells continue to evolve with the use of these methodologies both in diagnosis and research.

  18. A Physical Mechanism and Global Quantification of Breast Cancer

    Science.gov (United States)

    Yu, Chong; Wang, Jin

    2016-01-01

    Initiation and progression of cancer depend on many factors. Those on the genetic level are often considered crucial. To gain insight into the physical mechanisms of breast cancer, we construct a gene regulatory network (GRN) which reflects both genetic and environmental aspects of breast cancer. The construction of the GRN is based on available experimental data. Three basins of attraction, representing the normal, premalignant and cancer states respectively, were found on the phenotypic landscape. The progression of breast cancer can be seen as switching transitions between different state basins. We quantified the stabilities and kinetic paths of the three state basins to uncover the biological process of breast cancer formation. The gene expression levels at each state were obtained, which can be tested directly in experiments. Furthermore, by performing global sensitivity analysis on the landscape topography, six key genes (HER2, MDM2, TP53, BRCA1, ATM, CDK2) and four regulations (HER2⊣TP53, CDK2⊣BRCA1, ATM→MDM2, TP53→ATM) were identified as being critical for breast cancer. Interestingly, HER2 and MDM2 are the most popular targets for treating breast cancer. BRCA1 and TP53 are the most important oncogene of breast cancer and tumor suppressor gene, respectively. This further validates the feasibility of our model and the reliability of our prediction results. The regulation ATM→MDM2 has been extensive studied on DNA damage but not on breast cancer. We notice the importance of ATM→MDM2 on breast cancer. Previous studies of breast cancer have often focused on individual genes and the anti-cancer drugs are mainly used to target the individual genes. Our results show that the network-based strategy is more effective on treating breast cancer. The landscape approach serves as a new strategy for analyzing breast cancer on both the genetic and epigenetic levels and can help on designing network based medicine for breast cancer. PMID:27410227

  19. Identifying molecular targets of lifestyle modifications in colon cancer prevention

    Directory of Open Access Journals (Sweden)

    Molly Marie Derry

    2013-05-01

    Full Text Available One in four deaths in the United States is cancer-related, and colorectal cancer (CRC is the second leading cause of cancer-associated deaths. Screening strategies are utilized but have not reduced disease incidence or mortality. In this regard, there is an interest in cancer preventive strategies focusing on lifestyle intervention, where specific etiologic factors involved in cancer initiation, promotion, and progression could be targeted. For example, exposure to dietary carcinogens, such as nitrosamines and polycyclic aromatic hydrocarbons influences colon carcinogenesis. Furthermore, dietary deficiencies could alter sensitivity to genetic damage and influence carcinogen metabolism contributing to CRC. High alcohol consumption increases the risk of mutations including the fact that acetaldehyde, an ethanol metabolite, is classified as a group 1 carcinogen. Tobacco smoke exposure is also a risk factor for cancer development; ~20% of CRCs are associated with smoking. Additionally, obese patients have a higher risk of cancer development, which is further supported by the fact that physical activity decreases CRC risk by 55%. Similarly, chronic inflammatory conditions also increase the risk of CRC development. Moreover, the circadian clock alters digestion and regulates other biochemical, physiological and behavioral processes that could positively influence CRC. Taken together, colon carcinogenesis involves a number of etiological factors, and therefore, to create effective preventive strategies, molecular targets need to be identified and beleaguered prior to disease progression. With this in mind, the following is a comprehensive review identifying downstream target proteins of the above lifestyle risk factors, which are modulated during colon carcinogenesis and could be targeted for CRC prevention by novel agents including phytochemicals.

  20. Mechanistic insights into Mg2+-independent prenylation by CloQ from classical molecular mechanics and hybrid quantum mechanics/molecular mechanics molecular dynamics simulations.

    Science.gov (United States)

    Bayse, Craig A; Merz, Kenneth M

    2014-08-05

    Understanding the mechanism of prenyltransferases is important to the design of engineered proteins capable of synthesizing derivatives of naturally occurring therapeutic agents. CloQ is a Mg(2+)-independent aromatic prenyltransferase (APTase) that transfers a dimethylallyl group to 4-hydroxyphenylpyruvate in the biosynthetic pathway for clorobiocin. APTases consist of a common ABBA fold that defines a β-barrel containing the reaction cavity. Positively charged basic residues line the inside of the β-barrel of CloQ to activate the pyrophosphate leaving group to replace the function of the Mg(2+) cofactor in other APTases. Classical molecular dynamics simulations of CloQ, its E281G and F68S mutants, and the related NovQ were used to explore the binding of the 4-hydroxyphenylpyruvate (4HPP) and dimethylallyl diphosphate substrates in the reactive cavity and the role of various conserved residues. Hybrid quantum mechanics/molecular mechanics potential of mean force (PMF) calculations show that the effect of the replacement of the Mg(2+) cofactor with basic residues yields a similar activation barrier for prenylation to Mg(2+)-dependent APTases like NphB. The topology of the binding pocket for 4HPP is important for selective prenylation at the ortho position of the ring. Methylation at this position alters the conformation of the substrate for O-prenylation at the phenol group. Further, a two-dimensional PMF scan shows that a "reverse" prenylation product may be a possible target for protein engineering.

  1. Investigation of deformation mechanisms of staggered nanocomposites using molecular dynamics

    Science.gov (United States)

    Mathiazhagan, S.; Anup, S.

    2016-08-01

    Biological materials with nanostructure of regularly or stair-wise staggered arrangements of hard platelets reinforced in a soft protein matrix have superior mechanical properties. Applications of these nanostructures to ceramic matrix composites could enhance their toughness. Using molecular dynamics simulations, mechanical behaviour of the bio-inspired nanocomposites is studied. Regularly staggered model shows better flow behaviour compared to stair-wise staggered model due to the symmetrical crack propagation along the interface. Though higher stiffness and strength are obtained for stair-wise staggered models, rapid crack propagation reduces the toughness. Arresting this crack propagation could lead to superior mechanical properties in stair-wise staggered models.

  2. Molecular mechanisms underlying the fetal programming of adult disease.

    Science.gov (United States)

    Vo, Thin; Hardy, Daniel B

    2012-08-01

    Adverse events in utero can be critical in determining quality of life and overall health. It is estimated that up to 50 % of metabolic syndrome diseases can be linked to an adverse fetal environment. However, the mechanisms linking impaired fetal development to these adult diseases remain elusive. This review uncovers some of the molecular mechanisms underlying how normal physiology may be impaired in fetal and postnatal life due to maternal insults in pregnancy. By understanding the mechanisms, which include epigenetic, transcriptional, endoplasmic reticulum (ER) stress, and reactive oxygen species (ROS), we also highlight how intervention in fetal and neonatal life may be able to prevent these diseases long-term.

  3. Molecular analysis of precursor lesions in familial pancreatic cancer.

    Directory of Open Access Journals (Sweden)

    Tatjana Crnogorac-Jurcevic

    Full Text Available BACKGROUND: With less than a 5% survival rate pancreatic adenocarcinoma (PDAC is almost uniformly lethal. In order to make a significant impact on survival of patients with this malignancy, it is necessary to diagnose the disease early, when curative surgery is still possible. Detailed knowledge of the natural history of the disease and molecular events leading to its progression is therefore critical. METHODS AND FINDINGS: We have analysed the precursor lesions, PanINs, from prophylactic pancreatectomy specimens of patients from four different kindreds with high risk of familial pancreatic cancer who were treated for histologically proven PanIN-2/3. Thus, the material was procured before pancreatic cancer has developed, rather than from PanINs in a tissue field that already contains cancer. Genome-wide transcriptional profiling using such unique specimens was performed. Bulk frozen sections displaying the most extensive but not microdissected PanIN-2/3 lesions were used in order to obtain the holistic view of both the precursor lesions and their microenvironment. A panel of 76 commonly dysregulated genes that underlie neoplastic progression from normal pancreas to PanINs and PDAC were identified. In addition to shared genes some differences between the PanINs of individual families as well as between the PanINs and PDACs were also seen. This was particularly pronounced in the stromal and immune responses. CONCLUSIONS: Our comprehensive analysis of precursor lesions without the invasive component provides the definitive molecular proof that PanIN lesions beget cancer from a molecular standpoint. We demonstrate the need for accumulation of transcriptomic changes during the progression of PanIN to PDAC, both in the epithelium and in the surrounding stroma. An identified 76-gene signature of PDAC progression presents a rich candidate pool for the development of early diagnostic and/or surveillance markers as well as potential novel preventive

  4. A Modiifed Molecular Structure Mechanics Method for Analysis of Graphene

    Institute of Scientific and Technical Information of China (English)

    HUA Jun; LI Dongbo; ZHAO Dong; LIANG Shengwei; LIU Qinlong; JIA Ruiyan

    2015-01-01

    Based on molecular mechanics and the deformation characteristics of the atomic lattice structure of graphene, a modiifed molecular structure mechanics method was developed to improve the original one, that is, the semi-rigid connections were used to model the bond angle variations between the C-C bonds in graphene. The simulated results show that the equivalent space frame model with semi-rigid connections for graphene proposed in this article is a simple, efifcient, and accurate model to evaluate the equivalent elastic properties of graphene. Though the present computational model of the semi-rigid connected space frame is only applied to characterize the mechanical behaviors of the space lattices of graphene, it has more potential applications in the static and dynamic analyses of graphene and other nanomaterials.

  5. Molecular Mechanisms Underlying Genomic Instability in Brca-Deficient Cells

    Science.gov (United States)

    2014-11-01

    Instability during DNA Replication." 10: April 12, 2013-University of Zurich Cancer Mini-Symposium in Grindelwald, Switzerland - “Genome Stability during...53BP1DB, 53BP18A, o 45 min recovery) and immunoprecipitation was performed with anti- FLAG antib immunoprecipitated protein (right). (B) Isogenic...explore the mechanism of PTIP recruitment to DSBs, we expressed FLAG -tagged PTIP in WT, 53BP1/, and ATM/ MEFs and irradiated them with 10 Gy (Figure 6A

  6. Molecular mechanics methods for individual carbon nanotubes and nanotube assemblies

    Science.gov (United States)

    Eberhardt, Oliver; Wallmersperger, Thomas

    2015-04-01

    Since many years, carbon nanotubes (CNTs) have been considered for a wide range of applications due to their outstanding mechanical properties. CNTs are tubular structures, showing a graphene like hexagonal lattice. Our interest in the calculation of the mechanical properties is motivated by several applications which demand the knowledge of the material behavior. One application in which the knowledge of the material behavior is vital is the CNT based fiber. Due to the excellent stiffness and strength of the individual CNTs, these fibers are expected to be a promising successor for state of the art carbon fibers. However, the mechanical properties of the fibers fall back behind the properties of individual CNTs. It is assumed that this gap in the properties is a result of the van-der-Waals interactions of the individual CNTs within the fiber. In order to understand the mechanical behavior of the fibers we apply a molecular mechanics approach. The mechanical properties of the individual CNTs are investigated by using a modified structural molecular mechanics approach. This is done by calculating the properties of a truss-beam element framework representing the CNT with the help of a chemical force field. Furthermore, we also investigate the interactions of CNTs arranged in basic CNT assemblies, mimicking the ones in a simple CNT fiber. We consider the van-der-Waals interactions in the structure and calculate the potential surface of the CNT assemblies.

  7. Molecular mechanism of hepatitis B virus (HBV) on suppression of raf kinase inhibitor protein (RKIP) expression

    Science.gov (United States)

    Cheng, Xiao-Ke; Yu, Guo-Zheng; Li, Xiao-Dong; Ren, Xue-Qun

    2017-01-01

    Raf kinase inhibitor protein (RKIP) has been shown to be a suppressor of the mitogen-activated protein kinase pathway and is reported to be involved in human malignancy. However, the molecular mechanism of hepatitis B virus (HBV) in regulating RKIP expression is not yet clarified. In this study, we compared RKIP expression in 107 pairs of matched liver cancer and adjacent non-cancerous liver tissues. Among seven HBV-encoded proteins, we found HBV X (HBX) protein could significantly inhibit the expression level of RKIP, indicating that HBV could suppress RKIP expression through regulating HBX. To further elucidate the mechanism, analyses on transcriptional regulation and promoter methylation inhibition were conducted in Huh7 cells. Our results showed that HBX can interact with AP1 protein to inhibit the RKIP transcription. Moreover, we observed that the promoter methylation level of RKIP could be enhanced by HBV. In conclusion, our study revealed that RKIP could act as a molecular marker for HBV-infected liver cancer, but had no tumor-suppressing effect. PMID:27902472

  8. Protective mechanism against cancer found in progeria patient cells

    Science.gov (United States)

    NCI scientists have studied cells of patients with an extremely rare genetic disease that is characterized by drastic premature aging and discovered a new protective cellular mechanism against cancer. They found that cells from patients with Hutchinson Gi

  9. Molecular mechanisms of thyroid tumorigenesis; Molekulare Mechanismen der Schilddruesentumorgenese

    Energy Technology Data Exchange (ETDEWEB)

    Krause, K.; Fuehrer, D. [Universitaetsklinikum Leipzig (Germany). Abt. fuer Endokrinolgoie, Diabetologie und Nephrologie

    2008-09-15

    Thyroid nodules are the most frequent endocrine disorder and occur in approximately 30% of the German population. Thyroid nodular disease constitutes a very heterogeneous entity. A striking diversity of possible functional and morphological features of a thyroid tumour derived from the same thyroid ancestor cell, is a hallmark of thyroid tumorigenesis and is due to specific genetic alterations. Defects in known candidate genes can be found in up to 70% of differentiated thyroid carcinomas and determine the respective cancer phenotype. Papillary thyroid cancers (PTC) harbour BRAF (or much less frequently RAS) mutations in sporadically occurring tumours, while radiation-induced PTC display chromosomal rearrangements such as RET, TRK, APR9 / BRAF. These genetic events results in constitutive MAPKinase activation. Follicular thyroid cancers (FTC) harbour RAS mutations or PAX8/ PPAR{gamma} rearrangements, both of which, however have also been identified in follicular adenoma. In addition, recent studies show, that activation of PI3K/AKT signalling occurs with high frequency in follicular thyroid tumours. Undifferentiated (anaplastic) thyroid cancers (ATC) display genetic features of FTC or PTC, in addition to aberant activation of multiple tyrosinkinase pathways (overexpression or mutations in PI3K and MAPK pathways). This underscores the concept of a sequential evolution of ATC from differentiated thyroid cancer, a process widely conceived to be triggered by p53 inactivation. In contrast, the molecular pathogenesis of benign thyroid tumours, in particular cold thyroid nodules is less known, except for toxic thyroid nodules, which arise from constitutive activation of cAMP signalling, predominantly through TSHR mutations. (orig.)

  10. Biologia molecular do câncer cervical Molecular biology of cervical cancer

    Directory of Open Access Journals (Sweden)

    Waldemar Augusto Rivoire

    2006-01-01

    Full Text Available A carcinogênese é um processo de múltiplas etapas. Alterações no equilíbrio citogenético ocorrem na transformação do epitélio normal a câncer cervical. Numerosos estudos apoiam a hipótese de que a infecção por HPV está associada com o desenvolvimento de alterações malignas e pré-malignas do trato genital inferior. Neste trabalho são apresentadas as bases para a compreensão da oncogênese cervical. O ciclo celular é controlado por proto-oncogenes e genes supressores. Quando ocorrem mutações, proto-oncogenes tornam-se oncogenes, que são carcinogênicos e causam multiplicação celular excessiva. A perda da ação de genes supressores funcionais pode levar a célula ao crescimento inadequado. O ciclo celular também pode ser alterado pela ação de vírus, entre eles o HPV (Human Papiloma Virus, de especial interesse na oncogênese cervical. Os tipos de HPV 16 e 18 são os de maior interesse, freqüentemente associados a câncer cervical e anal. O conhecimento das bases moleculares que estão envolvidas na oncogênese cervical tem sido possível devido a utilização de técnicas avançadas de biologia molecular. A associação destas técnicas aos métodos diagnósticos clássicos, poderão levar a uma melhor avaliação das neoplasias cervicais e auxiliar no desenvolvimento de novas terapias, talvez menos invasivas e mais efetivas.Carcinogenesis involves several steps. Disorders of the cytogenetic balance occur during the evolution from normal epithelium to cervical cancer. Several studies support the hypothesis that the Human Papiloma Virus (HPV infection is associated to development of premalignant and malignant lesions of cervical cancer. In this review we show the basis to understand cervical oncogenesis. The cell cycle is controlled by protooncogenes and supressive genes. This orchestrated cell cycle can be affected by virus such as HPV. Of special interest in the cervical carcinogenesis are the HPV subtypes 16 and 18

  11. Optical contrast agents to visualize molecular expression in breast cancer

    Science.gov (United States)

    Langsner, Robert James

    Breast cancer is the second leading cause of death of women in the United States. Improvements in screening technology have increased the breast cancer incidence rate, as smaller lesions are being detected. Due to the small size of lesions, patients can choose to receive breast conservation therapy (BCT) rather than a modified radical mastectomy. Even though the breast retains cosmesis after BCT, there is an increased risk of the patient having residual microscopic disease, known as positive margins. Patients with positive margins receive increased radiation and have an increased chance of second surgery. Pathology with hematoxylin and eosin (H&E) remains the gold standard for diagnosing margin status in patients. Intraoperative pathology has been shown to reduce the rate of positive margins in BCT. However, a minority of surgery centers have intraoperative pathology centers, limiting the number of patients that receive this standard of care. The expression profiles of surface receptors such as ErbB2 (HER2-positive) and epidermal growth factor receptor (EGFR) provide information about the aggressiveness of a particular tumor. Recent research has shown that there was elevated EGFR expression in patients with a local recurrence even though the biopsies were assessed to be disease free using standard H&E. If the physicians had known the molecular expression of these biopsies, a different treatment regimen or excision of more tissue might have prevented the recurrence. This thesis investigates targeted molecular contrast agents that enhance the visualization of molecular markers such as glucose transporters (GLUTs) and growth factor receptors in tissue specimens. First, application of 2-NBDG, a fluorescent deoxyglucose, enhances signal in cancerous tissue with a 20-minute incubation. Then, antibody functionalized silica-gold nanoshells enhance the visualization of ErbB2 overexpression in specimens with a 5-minute incubation. To image these contrast agents in cancerous

  12. Microscopic and macroscopic polarization within a combined quantum mechanics and molecular mechanics model

    NARCIS (Netherlands)

    Jensen, L; Swart, M; van Duijnen, PT

    2005-01-01

    A polarizable quantum mechanics and molecular mechanics model has been extended to account for the difference between the macroscopic electric field and the actual electric field felt by the solute molecule. This enables the calculation of effective microscopic properties which can be related to mac

  13. Molecular dynamics simulations of diffusion mechanisms in NiAl

    Energy Technology Data Exchange (ETDEWEB)

    Soule De Bas, B.; Farkas, D

    2003-03-14

    Molecular dynamics simulations of the diffusion process in ordered B2 NiAl at high temperature were performed using an embedded atom interatomic potential. Diffusion occurs through a variety of cyclic mechanisms that accomplish the motion of the vacancy through nearest neighbor jumps restoring order to the alloy at the end of the cycle. The traditionally postulated six-jump cycle is only one of the various cycles observed and some of these are quite complex. A detailed sequential analysis of the observed six-jump cycles was performed and the results are analyzed in terms of the activation energies for individual jumps calculated using molecular statics simulations.

  14. Molecular mechanisms involved in mammalian primary sex determination.

    Science.gov (United States)

    She, Zhen-Yu; Yang, Wan-Xi

    2014-08-01

    Sex determination refers to the developmental decision that directs the bipotential genital ridge to develop as a testis or an ovary. Genetic studies on mice and humans have led to crucial advances in understanding the molecular fundamentals of sex determination and the mutually antagonistic signaling pathway. In this review, we summarize the current molecular mechanisms of sex determination by focusing on the known critical sex determining genes and their related signaling pathways in mammalian vertebrates from mice to humans. We also discuss the underlying delicate balance between testis and ovary sex determination pathways, concentrating on the antagonisms between major sex determining genes.

  15. Women at high risk of breast cancer: Molecular characteristics, clinical presentation and management.

    Science.gov (United States)

    Kleibl, Zdenek; Kristensen, Vessela N

    2016-08-01

    The presence of breast cancer in any first-degree female relative in general nearly doubles the risk for a proband and the risk gradually increases with the number of affected relatives. Current advances in molecular oncology and oncogenetics may enable the identification of high-risk individuals with breast-cancer predisposition. The best-known forms of hereditary breast cancer (HBC) are caused by mutations in the high-penetrance genes BRCA1 and BRCA2. Other genes, including PTEN, TP53, STK11/LKB1, CDH1, PALB2, CHEK2, ATM, MRE11, RAD50, NBS1, BRIP1, FANCA, FANCC, FANCM, RAD51, RAD51B, RAD51C, RAD51D, and XRCC2 have been described as high- or moderate-penetrance breast cancer-susceptibility genes. The majority of breast cancer-susceptibility genes code for tumor suppressor proteins that are involved in critical processes of DNA repair pathways. This is of particular importance for those women who, due to their increased risk of breast cancer, may be subjected to more frequent screening but due to their repair deficiency might be at the risk of developing radiation-induced malignancies. It has been proven that cancers arising from the most frequent BRCA1 gene mutation carriers differ significantly from the sporadic disease of age-matched controls in their histopathological appearances and molecular characteristics. The increased depth of mutation detection brought by next-generation sequencing and a better understanding of the mechanisms through which these mutations cause the disease will bring novel insights in terms of oncological prevention, diagnostics, and therapeutic options for HBC patients.

  16. Targeting Cell Surface Proteins in Molecular Photoacoustic Imaging to Detect Ovarian Cancer Early

    Science.gov (United States)

    2013-07-01

    10-1-0422 TITLE: Targeting Cell Surface Proteins in Molecular Photoacoustic Imaging to Detect Ovarian Cancer Early PRINCIPAL...DATES COVERED 1 July 2010 - 30 June 2013 4. TITLE AND SUBTITLE Targeting Cell Surface Proteins in Molecular 5a. CONTRACT NUMBER Photoacoustic ...upon request). Aim 2) Prioritize ovarian cancer-associated surface proteins for their utility as molecular photoacoustic imaging targets and

  17. Molecular Modification of Metadherin/MTDH Impacts the Sensitivity of Breast Cancer to Doxorubicin.

    Directory of Open Access Journals (Sweden)

    Zhenchuan Song

    Full Text Available Breast cancer is a leading cause of death in women and with an increasing worldwide incidence. Doxorubicin, as a first-line anthracycline-based drug is conventional used on breast cancer clinical chemotherapy. However, the drug resistances limited the curative effect of the doxorubicin therapy in breast cancer patients, but the molecular mechanism determinants of breast cancer resistance to doxorubicin chemotherapy are not fully understood. In order to explore the association between metadherin (MTDH and doxorubicin sensitivity, the differential expressions of MTDH in breast cancer cell lines and the sensitivity to doxorubicin of breast cancer cell lines were investigated.The mRNA and protein expression of MTDH were determined by real-time PCR and Western blot in breast cancer cells such as MDA-MB-231, MCF-7, MDA-MB-435S, MCF-7/ADR cells. Once MTDH gene was knocked down by siRNA in MCF-7/ADR cells and overexpressed by MTDH plasmid transfection in MDA-MB-231 cells, the cell growth and therapeutic sensitivity of doxorubicin were evaluated using MTT and the Cell cycle assay and apoptosis rate was determined by flow cytometry.MCF-7/ADR cells revealed highly expressed MTDH and MDA-MB-231 cells had the lowest expression of MTDH. After MTDH gene was knocked down, the cell proliferation was inhibited, and the inhibitory rate of cell growth and apoptosis rate were enhanced, and the cell cycle arrest during the G0/G1 phase in the presence of doxorubicin treatment. On the other hand, the opposite results were observed in MDA-MB-231 cells with overexpressed MTDH gene.MTDH gene plays a promoting role in the proliferation of breast cancer cells and its high expression may be associated with doxorubicin sensitivity of breast cancer.

  18. Quantum Mechanical/Molecular Mechanical Studies on Spectral Tuning Mechanisms of Visual Pigments and Other Photoactive Proteins†

    Science.gov (United States)

    Altun, Ahmet; Yokoyama, Shozo; Morokuma, Keiji

    2008-01-01

    The protein environments surrounding the retinal tune electronic absorption maximum from 350 to 630 nm. Hybrid quantum mechanical/molecular mechanical (QM/MM) methods can be used in calculating excitation energies of retinal in its native protein environments and in studying the molecular basis of spectral tuning. We hereby review recent QM/MM results on the phototransduction of bovine rhodopsin, bacteriorhodopsin, sensory rhodopsin II, nonretinal photoactive yellow protein and their mutants. PMID:18331400

  19. Quantum Mechanical/Molecular Mechanical Studies on Spectral Tuning Mechanisms of Visual Pigments and Other Photoactive Proteins†

    OpenAIRE

    Altun, Ahmet; Yokoyama, Shozo; Morokuma, Keiji

    2008-01-01

    The protein environments surrounding the retinal tune electronic absorption maximum from 350 to 630 nm. Hybrid quantum mechanical/molecular mechanical (QM/MM) methods can be used in calculating excitation energies of retinal in its native protein environments and in studying the molecular basis of spectral tuning. We hereby review recent QM/MM results on the phototransduction of bovine rhodopsin, bacteriorhodopsin, sensory rhodopsin II, nonretinal photoactive yellow protein and their mutants.

  20. Genetic classification and molecular mechanisms of primary dystonia

    Institute of Scientific and Technical Information of China (English)

    Xueping Chen; Huifang Shang; Zuming Luo

    2008-01-01

    BACKGROUND: Primary dystonia is a heterogeneous disease, with a complex genetic basis. In previous studies, primary dystonia was classified according to age of onset, involved regions, and other clinical characteristics. With the development of molecular genetics, new virulence genes and sites have been discovered. Therefore, there is a gradual understanding of the various forms of dystonia, based on new viewpoints. There are 15 subtypes of dystonia, based on the molecular level, i.e., DYT1 to DYT15. OBJECTIVE: To analyze the genetic development of dystonia in detail, and to further investigate molecular mechanisms of dystonia. RETRIEVAL STRATEGY: A computer-based online search was conducted in PubMed for English language publications containing the keywords "dystonia and genetic" from January 1980 to March 2007. There were 105 articles in total. Inclusion criteria: ① the contents of the articles should closely address genetic classification and molecular mechanisms of primary dystonia; ② the articles published in recent years or in high-impact journals took preference. Exclusion criteria: duplicated articles. LITERATURE EVALUATION: The selected articles were on genetic classification and molecular genetics mechanism of primary dystonia. Of those, 27 were basic or clinical studies. DATA SYNTHESIS: ① Dystonia is a heterogeneous disease, with a complex genetic basis. According to the classification of the Human Genome Organization, there are 15 dystonia subtypes, based on genetics, i.e., DYT1-DYT15,including primary dystonia, dystonia plus syndrome, degeneration plus dystonia, and paroxysmal dyskinesia plus dystonia. ② To date, the chromosomes of 13 subtypes have been localized; however, DYT2 and DYT4 remain unclear. Six subtypes have been located within virulence genes. Specifically, torsinA gene expression results in the DYT1 genotype; autosomal dominant GTP cyclohydrolase I gene expression and recessive tyrosine hydroxylase expression result in the DYT5

  1. Molecular diagnosis of lung cancer: an overview of recent developments.

    Science.gov (United States)

    Mutti, Antonio

    2008-01-01

    Health surveillance of workers occupationally exposed to lung carcinogens calls for screening procedures which may not be fully justified, owing to current uncertainties about the outcome of early detection. Indeed, bias-free designs are difficult to set up, and the effects of lead time, length and screening biases can all result in an overestimation of the benefits of screenings, which certainly increase survival, but without any actual reduction of mortality. A major issue with modern imaging techniques is the very high incidence of discovery of lung nodules, usually false positive, but still calling for additional and sometimes painful examinations. Currently, the differential diagnosis is mainly based on additional imaging approaches, particularly positron emission tomography, which is very expensive and also shows limitations in terms of sensitivity and specificity. Therefore, purely morphological criteria seem to be insufficient to distinguish lung cancer at early stages from benign nodules with sufficient confidence. A molecular approach to the diagnosis of lung cancer through biomarkers measured by non-invasive means could greatly improve the specificity of imaging procedures. Extremely sensitive mass spectrometric techniques and polymerase chain reaction-based methods are available to detect, in accessible media, molecular alterations which characterise lung cancer at an early stage, thereby reducing the rate of false positives. The lessons learnt from decades of screening programmes based on imaging and the future prospects possibly enhanced by using biomarkers are briefly discussed in this overview. (www.actabiomedica.it)

  2. Emerging Molecularly Targeted Therapies in Castration Refractory Prostate Cancer

    Directory of Open Access Journals (Sweden)

    Jesal C. Patel

    2013-01-01

    Full Text Available Androgen deprivation therapy (ADT with medical or surgical castration is the mainstay of therapy in men with metastatic prostate cancer. However, despite initial responses, almost all men eventually develop castration refractory metastatic prostate cancer (CRPC and die of their disease. Over the last decade, it has been recognized that despite the failure of ADT, most prostate cancers maintain some dependence on androgen and/or androgen receptor (AR signaling for proliferation. Furthermore, androgen independent molecular pathways have been identified as drivers of continued progression of CRPC. Subsequently, drugs have been developed targeting these pathways, many of which have received regulatory approval. Agents such as abiraterone, enzalutamide, orteronel (TAK-700, and ARN-509 target androgen signaling. Sipuleucel-T, ipilimumab, and tasquinimod augment immune-mediated tumor killing. Agents targeting classic tumorogenesis pathways including vascular endothelial growth factor, hepatocyte growth factor, insulin like growth factor-1, tumor suppressor, and those which regulate apoptosis and cell cycles are currently being developed. This paper aims to focus on emerging molecular pathways underlying progression of CRPC, and the drugs targeting these pathways, which have recently been approved or have reached advanced stages of development in either phase II or phase III clinical trials.

  3. Guidance for laboratories performing molecular pathology for cancer patients.

    Science.gov (United States)

    Cree, Ian A; Deans, Zandra; Ligtenberg, Marjolijn J L; Normanno, Nicola; Edsjö, Anders; Rouleau, Etienne; Solé, Francesc; Thunnissen, Erik; Timens, Wim; Schuuring, Ed; Dequeker, Elisabeth; Murray, Samuel; Dietel, Manfred; Groenen, Patricia; Van Krieken, J Han

    2014-11-01

    Molecular testing is becoming an important part of the diagnosis of any patient with cancer. The challenge to laboratories is to meet this need, using reliable methods and processes to ensure that patients receive a timely and accurate report on which their treatment will be based. The aim of this paper is to provide minimum requirements for the management of molecular pathology laboratories. This general guidance should be augmented by the specific guidance available for different tumour types and tests. Preanalytical considerations are important, and careful consideration of the way in which specimens are obtained and reach the laboratory is necessary. Sample receipt and handling follow standard operating procedures, but some alterations may be necessary if molecular testing is to be performed, for instance to control tissue fixation. DNA and RNA extraction can be standardised and should be checked for quality and quantity of output on a regular basis. The choice of analytical method(s) depends on clinical requirements, desired turnaround time, and expertise available. Internal quality control, regular internal audit of the whole testing process, laboratory accreditation, and continual participation in external quality assessment schemes are prerequisites for delivery of a reliable service. A molecular pathology report should accurately convey the information the clinician needs to treat the patient with sufficient information to allow for correct interpretation of the result. Molecular pathology is developing rapidly, and further detailed evidence-based recommendations are required for many of the topics covered here.

  4. The Fluid Mechanics of Cancer and Its Therapy

    Science.gov (United States)

    Koumoutsakos, Petros; Pivkin, Igor; Milde, Florian

    2013-01-01

    Fluid mechanics is involved in the growth, progression, metastasis, and therapy of cancer. Blood vessels transport oxygen and nutrients to cancerous tissues, provide a route for metastasizing cancer cells to distant organs, and deliver drugs to tumors. The irregular and leaky tumor vasculature is responsible for increased interstitial pressure in the tumor microenvironment, whereas multiscale flow-structure interaction processes control tumor growth, metastasis, and nanoparticle-mediated drug delivery. We outline these flow-mediated processes, along with related experimental and computational methods for the diagnosis, predictive modeling, and therapy of cancer.

  5. A quantum mechanics/molecular mechanics study on the hydrolysis mechanism of New Delhi metallo-β-lactamase-1

    Science.gov (United States)

    Zhu, Kongkai; Lu, Junyan; Liang, Zhongjie; Kong, Xiangqian; Ye, Fei; Jin, Lu; Geng, Heji; Chen, Yong; Zheng, Mingyue; Jiang, Hualiang; Li, Jun-Qian; Luo, Cheng

    2013-03-01

    New Delhi metallo-β-lactamase-1 (NDM-1) has emerged as a major global threat to human health for its rapid rate of dissemination and ability to make pathogenic microbes resistant to almost all known β-lactam antibiotics. In addition, effective NDM-1 inhibitors have not been identified to date. In spite of the plethora of structural and kinetic data available, the accurate molecular characteristics of and details on the enzymatic reaction of NDM-1 hydrolyzing β-lactam antibiotics remain incompletely understood. In this study, a combined computational approach including molecular docking, molecular dynamics simulations and quantum mechanics/molecular mechanics calculations was performed to characterize the catalytic mechanism of meropenem catalyzed by NDM-1. The quantum mechanics/molecular mechanics results indicate that the ionized D124 is beneficial to the cleavage of the C-N bond within the β-lactam ring. Meanwhile, it is energetically favorable to form an intermediate if no water molecule coordinates to Zn2. Moreover, according to the molecular dynamics results, the conserved residue K211 plays a pivotal role in substrate binding and catalysis, which is quite consistent with previous mutagenesis data. Our study provides detailed insights into the catalytic mechanism of NDM-1 hydrolyzing meropenem β-lactam antibiotics and offers clues for the discovery of new antibiotics against NDM-1 positive strains in clinical studies.

  6. A quantum mechanics/molecular mechanics study on the hydrolysis mechanism of New Delhi metallo-β-lactamase-1.

    Science.gov (United States)

    Zhu, Kongkai; Lu, Junyan; Liang, Zhongjie; Kong, Xiangqian; Ye, Fei; Jin, Lu; Geng, Heji; Chen, Yong; Zheng, Mingyue; Jiang, Hualiang; Li, Jun-Qian; Luo, Cheng

    2013-03-01

    New Delhi metallo-β-lactamase-1 (NDM-1) has emerged as a major global threat to human health for its rapid rate of dissemination and ability to make pathogenic microbes resistant to almost all known β-lactam antibiotics. In addition, effective NDM-1 inhibitors have not been identified to date. In spite of the plethora of structural and kinetic data available, the accurate molecular characteristics of and details on the enzymatic reaction of NDM-1 hydrolyzing β-lactam antibiotics remain incompletely understood. In this study, a combined computational approach including molecular docking, molecular dynamics simulations and quantum mechanics/molecular mechanics calculations was performed to characterize the catalytic mechanism of meropenem catalyzed by NDM-1. The quantum mechanics/molecular mechanics results indicate that the ionized D124 is beneficial to the cleavage of the C-N bond within the β-lactam ring. Meanwhile, it is energetically favorable to form an intermediate if no water molecule coordinates to Zn2. Moreover, according to the molecular dynamics results, the conserved residue K211 plays a pivotal role in substrate binding and catalysis, which is quite consistent with previous mutagenesis data. Our study provides detailed insights into the catalytic mechanism of NDM-1 hydrolyzing meropenem β-lactam antibiotics and offers clues for the discovery of new antibiotics against NDM-1 positive strains in clinical studies.

  7. Challenges and opportunities in international molecular cancer prevention research: An ASPO Molecular Epidemiology and the Environment and International Cancer Prevention Interest Groups Report.

    Science.gov (United States)

    Epplein, Meira; Bostick, Roberd M; Mu, Lina; Ogino, Shuji; Braithwaite, Dejana; Kanetsky, Peter A

    2014-11-01

    The International Agency for Research on Cancer estimates that over half of the new cancer cases and almost two-thirds of the cancer deaths in 2012 occurred in low and middle income countries. To discuss the challenges and opportunities to reducing the burden of cancer worldwide, the Molecular Epidemiology and the Environment and the International Issues in Cancer Special Interest Groups joined forces to hold a session during the 38th Annual Meeting of the American Society of Preventive Oncology (March 2014, Arlington, Virginia). The session highlighted three topics of particular interest to molecular cancer prevention researchers working internationally, specifically: 1) biomarkers in cancer research; 2) environmental exposures and cancer; and 3) molecular pathological epidemiology. A major factor for successful collaboration illuminated during the discussion was the need for strong, committed, and reliable international partners. A key element of establishing such relationships is to thoroughly involve individual international collaborators in the development of the research question; engaged international collaborators are particularly motivated to champion and shepherd the project through all necessary steps, including issues relating to institutional review boards, political sensitivity, laboratory-based assays, and tumor subtyping. Also essential is allotting time for the building, maintaining, and investing in such relationships so that successful international collaborations may take root and bloom. While there are many challenges inherent to international molecular cancer research, the opportunities for furthering the science and prevention of cancer worldwide are great, particularly at this time of increasing cancer incidence and prevalence in low and middle income countries.

  8. Atomistic insight into the catalytic mechanism of glycosyltransferases by combined quantum mechanics/molecular mechanics (QM/MM) methods.

    Science.gov (United States)

    Tvaroška, Igor

    2015-02-11

    Glycosyltransferases catalyze the formation of glycosidic bonds by assisting the transfer of a sugar residue from donors to specific acceptor molecules. Although structural and kinetic data have provided insight into mechanistic strategies employed by these enzymes, molecular modeling studies are essential for the understanding of glycosyltransferase catalyzed reactions at the atomistic level. For such modeling, combined quantum mechanics/molecular mechanics (QM/MM) methods have emerged as crucial. These methods allow the modeling of enzymatic reactions by using quantum mechanical methods for the calculation of the electronic structure of the active site models and treating the remaining enzyme environment by faster molecular mechanics methods. Herein, the application of QM/MM methods to glycosyltransferase catalyzed reactions is reviewed, and the insight from modeling of glycosyl transfer into the mechanisms and transition states structures of both inverting and retaining glycosyltransferases are discussed.

  9. MicroRNAs and cancer resistance: A new molecular plot.

    Science.gov (United States)

    Fanini, F; Fabbri, M

    2016-05-01

    The most common cause of cancer relapse is drug resistance, acquired or intrinsic, which strongly limits the efficacy of both conventional and new targeted chemotherapy. MicroRNAs (miRNAs) are a growing, large family of short noncoding RNAs frequently dysregulated in malignancies. Although the mechanism of miRNA-mediated drug resistance is not fully understood, an increasing amount of evidence suggests their involvement in the acquisition of tumor cell drug resistance, pointing towards the need for novel and more innovative therapeutic approaches. Use of antagomiRs or mimics can modulate specific miRNAs in order to restore gene networks and signaling pathways, perhaps optimizing chemotherapies by increasing cancer cell sensitivity to drugs. The aim of this review is to provide a state-of-the-art scenario with regard to the most recent discoveries in the field of miRNAs involved in the process of resistance to cancer therapy.

  10. Delineating Molecular Mechanisms of Squamous Tissue Homeostasis and Neoplasia: Focus on p63

    Directory of Open Access Journals (Sweden)

    Kathryn E. King

    2013-01-01

    Full Text Available Mouse models have informed us that p63 is critical for normal epidermal development and homeostasis. The p53/p63/p73 family is expressed as multiple protein isoforms due to a combination of alternative promoter usage and C-terminal alternative splicing. These isoforms can mimic or interfere with one another, and their balance ultimately determines biological outcome in a context-dependent manner. While not frequently mutated, p63, and in particular the ΔNp63 subclass, is commonly overexpressed in human squamous cell cancers. In vitro keratinocytes and murine transgenic and transplantation models have been invaluable in elucidating the contribution of altered p63 levels to cancer development, and studies have identified the roles for ΔNp63 isoforms in keratinocyte survival and malignant progression, likely due in part to their transcriptional regulatory function. These findings can be extended to human cancers; for example, the novel recognition of NFκB/c-Rel as a downstream effector of p63 has identified a role for NFκB/c-Rel in human squamous cell cancers. These models will be critical in enhancing the understanding of the specific molecular mechanisms of cancer development and progression.

  11. Molecular Characterization of ERα-positive and Triple Negative Breast Cancer

    NARCIS (Netherlands)

    Severson, T.M.

    2016-01-01

    Breast cancer, one of the most common of all cancers, is diagnosed in over 1.5 million people world-wide each year. Overall, treatments for breast cancer are considered relatively successful, however recurrence is a clinical problem of paramount importance. Molecular subtypes of breast cancer, defin

  12. Molecular Endoscopic Ultrasound for Diagnosis of Pancreatic Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Bournet, Barbara [Department of Gastroenterology, University Hospital Center Rangueil, 1 avenue Jean Poulhès, TSA 50032, 31059 Toulouse Cedex 9 (France); INSERM U1037, University Hospital Center Rangueil, Toulouse (France); Pointreau, Adeline; Delpu, Yannick; Selves, Janick; Torrisani, Jerome [INSERM U1037, University Hospital Center Rangueil, Toulouse (France); Buscail, Louis, E-mail: buscail.l@chu-toulouse.fr [Department of Gastroenterology, University Hospital Center Rangueil, 1 avenue Jean Poulhès, TSA 50032, 31059 Toulouse Cedex 9 (France); INSERM U1037, University Hospital Center Rangueil, Toulouse (France); Cordelier, Pierre [INSERM U1037, University Hospital Center Rangueil, Toulouse (France)

    2011-02-24

    Endoscopic ultrasound-guided fine needle aspiration-biopsy is a safe and effective technique in diagnosing and staging of pancreatic ductal adenocarcinoma. However its predictive negative value does not exceed 50% to 60%. Unfortunately, the majority of pancreatic cancer patients have a metastatic and/or a locally advanced disease (i.e., not eligible for curative resection) which explains the limited access to pancreatic tissue specimens. Endoscopic ultrasound-guided fine needle aspiration-biopsy is the most widely used approach for cytological and histological material sampling in these situations used in up to two thirds of patients with pancreatic cancer. Based on this unique material, we and others developed strategies to improve the differential diagnosis between carcinoma and inflammatory pancreatic lesions by analysis of KRAS oncogene mutation, microRNA expression and methylation, as well as mRNA expression using both qRT-PCR and Low Density Array Taqman analysis. Indeed, differentiating pancreatic cancer from pseudotumoral chronic pancreatitis remains very difficult in current clinical practice, and endoscopic ultrasound-guided fine needle aspiration-biopsy analysis proved to be very helpful. In this review, we will compile the clinical and molecular advantages of using endoscopic ultrasound-guided fine needle aspiration-biopsy in managing pancreatic cancer.

  13. Review of Histopathological and Molecular Prognostic Features in Colorectal Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Marzouk, Ola; Schofield, John, E-mail: john.schofield@nhs.net [Department of Cellular Pathology, Maidstone Hospital, Hermitage Lane, Maidstone, Kent ME16 9QQ (United Kingdom)

    2011-06-23

    Prediction of prognosis in colorectal cancer is vital for the choice of therapeutic options. Histopathological factors remain paramount in this respect. Factors such as tumor size, histological type and subtype, presence of signet ring morphology and the degree of differentiation as well as the presence of lymphovascular invasion and lymph node involvement are well known factors that influence outcome. Our understanding of these factors has improved in the past few years with factors such as tumor budding, lymphocytic infiltration being recognized as important. Likewise the prognostic significance of resection margins, particularly circumferential margins has been appreciated in the last two decades. A number of molecular and genetic markers such as KRAS, BRAF and microsatellite instability are also important and correlate with histological features in some patients. This review summarizes our current understanding of the main histopathological factors that affect prognosis of colorectal cancer.

  14. Review of Histopathological and Molecular Prognostic Features in Colorectal Cancer

    Directory of Open Access Journals (Sweden)

    John Schofield

    2011-06-01

    Full Text Available Prediction of prognosis in colorectal cancer is vital for the choice of therapeutic options. Histopathological factors remain paramount in this respect. Factors such as tumor size, histological type and subtype, presence of signet ring morphology and the degree of differentiation as well as the presence of lymphovascular invasion and lymph node involvement are well known factors that influence outcome. Our understanding of these factors has improved in the past few years with factors such as tumor budding, lymphocytic infiltration being recognized as important. Likewise the prognostic significance of resection margins, particularly circumferential margins has been appreciated in the last two decades. A number of molecular and genetic markers such as KRAS, BRAF and microsatellite instability are also important and correlate with histological features in some patients. This review summarizes our current understanding of the main histopathological factors that affect prognosis of colorectal cancer.

  15. Mangiferin in cancer chemoprevention and treatment: pharmacokinetics and molecular targets.

    Science.gov (United States)

    Rajendran, Peramaiyan; Rengarajan, Thamaraiselvan; Nandakumar, Natarajan; Divya, H; Nishigaki, Ikuo

    2015-02-01

    A variety of bioactive food components have been shown to modulate inflammatory responses and to attenuate carcinogenesis. Polyphenols isolated several years ago from various medicinal plants now seem to have a prominent role in the prevention and therapy of a variety of ailments. Mangiferin, a unique, important, and highly investigated polyphenol, has attracted much attention of late for its potential as a chemopreventive and chemotherapeutic agent against various types of cancer. Mangiferin has been shown to target multiple proinflammatory transcription factors, cell- cycle proteins, growth factors, kinases, cytokines, chemokines, adhesion molecules, and inflammatory enzymes. These targets can potentially mediate the chemopreventive and therapeutic effects of mangiferin by inhibiting the initiation, promotion, and metastasis of cancer. This review not only summarizes the diverse molecular targets of mangiferin, but also gives the results of various preclinical studies that have been performed in the last decade with this promising polyphenol.

  16. Pancreatic Cancer Gene Therapy: From Molecular Targets to Delivery Systems

    Energy Technology Data Exchange (ETDEWEB)

    Fillat, Cristina, E-mail: cristina.fillat@crg.es; Jose, Anabel; Ros, Xavier Bofill-De; Mato-Berciano, Ana; Maliandi, Maria Victoria; Sobrevals, Luciano [Programa Gens i Malaltia, Centre de Regulació Genòmica-CRG, UPF, Parc de Recerca Biomedica de Barcelona-PRBB and Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Barcelona (Spain)

    2011-01-18

    The continuous identification of molecular changes deregulating critical pathways in pancreatic tumor cells provides us with a large number of novel candidates to engineer gene-targeted approaches for pancreatic cancer treatment. Targets—both protein coding and non-coding—are being exploited in gene therapy to influence the deregulated pathways to facilitate cytotoxicity, enhance the immune response or sensitize to current treatments. Delivery vehicles based on viral or non-viral systems as well as cellular vectors with tumor homing characteristics are a critical part of the design of gene therapy strategies. The different behavior of tumoral versus non-tumoral cells inspires vector engineering with the generation of tumor selective products that can prevent potential toxic-associated effects. In the current review, a detailed analysis of the different targets, the delivery vectors, the preclinical approaches and a descriptive update on the conducted clinical trials are presented. Moreover, future possibilities in pancreatic cancer treatment by gene therapy strategies are discussed.

  17. Mechanisms of Cancer Induction by Tobacco-Specific NNK and NNN

    Energy Technology Data Exchange (ETDEWEB)

    Xue, Jiaping [Department of Physiology and Biophysics, University of Illinois at Chicago, Chicago, IL 60612 (United States); Yang, Suping; Seng, Seyha, E-mail: sseng@bidmc.harvard.edu [Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215 (United States)

    2014-05-14

    Tobacco use is a major public health problem worldwide. Tobacco-related cancers cause millions of deaths annually. Although several tobacco agents play a role in the development of tumors, the potent effects of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) and N'-nitrosonornicotine (NNN) are unique. Metabolically activated NNK and NNN induce deleterious mutations in oncogenes and tumor suppression genes by forming DNA adducts, which could be considered as tumor initiation. Meanwhile, the binding of NNK and NNN to the nicotinic acetylcholine receptor promotes tumor growth by enhancing and deregulating cell proliferation, survival, migration, and invasion, thereby creating a microenvironment for tumor growth. These two unique aspects of NNK and NNN synergistically induce cancers in tobacco-exposed individuals. This review will discuss various types of tobacco products and tobacco-related cancers, as well as the molecular mechanisms by which nitrosamines, such as NNK and NNN, induce cancer.

  18. Mechanisms Involved in the Pro-Apoptotic Effect of Melatonin in Cancer Cells

    Directory of Open Access Journals (Sweden)

    Isaac Antolín

    2013-03-01

    Full Text Available It is well established that melatonin exerts antitumoral effects in many cancer types, mostly decreasing cell proliferation at low concentrations. On the other hand, induction of apoptosis by melatonin has been described in the last few years in some particular cancer types. The cytotoxic effect occurs after its administration at high concentrations, and the molecular pathways involved have been only partially determined. Moreover, a synergistic effect has been found in several cancer types when it is administered in combination with chemotherapeutic agents. In the present review, we will summarize published work on the pro-apoptotic effect of melatonin in cancer cells and the reported mechanisms involved in such action. We will also construct a hypothesis on how different cell signaling pathways may relate each other on account for such effect.

  19. Molecular Insights into Division of Single Human Cancer Cells in On-Chip Transparent Microtubes

    Science.gov (United States)

    2016-01-01

    In vivo, mammalian cells proliferate within 3D environments consisting of numerous microcavities and channels, which contain a variety of chemical and physical cues. External environments often differ between normal and pathological states, such as the unique spatial constraints that metastasizing cancer cells experience as they circulate the vasculature through arterioles and narrow capillaries, where they can divide and acquire elongated cylindrical shapes. While metastatic tumors cause most cancer deaths, factors impacting early cancer cell proliferation inside the vasculature and those that can promote the formation of secondary tumors remain largely unknown. Prior studies investigating confined mitosis have mainly used 2D cell culture systems. Here, we mimic aspects of metastasizing tumor cells dividing inside blood capillaries by investigating single-cell divisions of living human cancer cells, trapped inside 3D rolled-up, transparent nanomembranes. We assess the molecular effects of tubular confinement on key mitotic features, using optical high- and super-resolution microscopy. Our experiments show that tubular confinement affects the morphology and dynamics of the mitotic spindle, chromosome arrangements, and the organization of the cell cortex. Moreover, we reveal that membrane blebbing and/or associated processes act as a potential genome-safety mechanism, limiting the extent of genomic instability caused by mitosis in confined circumstances, especially in tubular 3D microenvironments. Collectively, our study demonstrates the potential of rolled-up nanomembranes for gaining molecular insights into key cellular events occurring in tubular 3D microenvironments in vivo. PMID:27267364

  20. Molecular mechanisms of insulin resistance in chronic hepatitis C

    Institute of Scientific and Technical Information of China (English)

    Mark W Douglas; Jacob George

    2009-01-01

    It is now widely recognized that chronic hepatitis C (CHC) is associated with insulin resistance (IR) and type 2 diabetes, so can be considered a metabolic disease. IR is most strongly associated with hepatitis C virus (HCV) genotype 1, in contrast to hepatic steatosis, which is associated with genotype 3 infection. Apart from the well-described complications of diabetes, IR in CHC predicts faster progression to fibrosis and cirrhosis that may culminate in liver failure and hepatocellular carcinoma. More recently, it has been recognized that IR in CHC predicts a poor response to antiviral therapy. The molecular mechanisms for the association between IR and HCV infection are not well defined. This review will elaborate on the clinical associations between CHC and IR and summarize current knowledge regarding the molecular mechanisms that potentially mediate HCV-associated IR.

  1. Lobular breast cancer: Clinical, molecular and morphological characteristics.

    Science.gov (United States)

    Christgen, Matthias; Steinemann, Doris; Kühnle, Elna; Länger, Florian; Gluz, Oleg; Harbeck, Nadia; Kreipe, Hans

    2016-07-01

    Infiltrating lobular breast cancer (ILBC) is the most common special breast cancer subtype. This review provides a comprehensive description of ILBC characteristics, including epidemiology, clinical features, molecular genetics and histomorphology. Twenty detailed supplemental data tables guide through primary data of more than 200 original studies. Meta-analyses indicate that ILBC is at least twice as common in the Western world as it is in other geographic regions. ILBC is over-represented in so-called interval carcinomas and in primary metastatic breast cancer. ILBC is also associated higher age, higher pT stage and hormone receptor (ER/PR) positivity. Pathological complete response rates after neoadjuvant chemotherapy are low, ranging between 0% and 11%. Positive resection margins after breast-conserving surgery are comparatively frequent and 17% to 65% of patients undergo a second surgical intervention. Depending on the morphological stringency in the diagnosis of ILBC, lack of E-cadherin expression is observed in 55% to 100% of cases. CDH1/E-cadherin mutation detection rates vary between 12% and 83%. Various additional molecular factors, including PIK3CA, TP53, FOXA1, FGFR1, ZNF703 and BCAR4, have been implicated in ILBC or progression of lobular carcinoma in situ (LCIS) to invasive cancer and are discussed in detail. Eight instructive figure plates recapitulate the histomorphology of ILBC and its variants. Furthermore, we draw attention to rarely addressed histological details, such as two-sided nuclear compression and fat-avoiding growth at the invasion front. Last but not least, we discuss future translational research directions and emphasize the concept of synthetic lethality, which promises new options for targeted ILBC therapy.

  2. Molecular Mechanisms of Casticin in Intervention of Cancer Cell Metastasis in Esophagus Squamous Cell Carci-noma%紫花牡荆素干预食管鳞状细胞癌细胞转移的分子机制

    Institute of Scientific and Technical Information of China (English)

    冉永刚; 游颜杰; 李海军

    2015-01-01

    目的 研究紫花牡荆素对人食管鳞状细胞癌(食管鳞癌)细胞恶性转移能力的抑制效应并探讨其分子机制. 方法 人食管鳞癌细胞株EC9706与EC109细胞经紫花牡荆素处理后,以MTT比色法测定细胞增殖能力,侵袭与迁移实验检测细胞转移能力,Western blot检测转移相关蛋白表达变化. 结果 不同浓度紫花牡荆素处理可显著抑制EC9706与EC109细胞的增殖、侵袭与迁移能力,同未加药组比较差异均有统计学意义(P<0. 05);紫花牡荆素处理下调兔抗人血管内皮生长因子(vascular endothelial growth factor,VEGF)、基质金属蛋白酶2(matrix metalloprotein-ase2,MMP2)与基质金属蛋白酶9(matrix metalloproteinase9,MMP9)表达水平,上调上皮细胞钙黏蛋白(E-cadherin)、周期素依赖性激酶10(cyclin-dependent kinase 10, CDK10)与兔抗人受体O型蛋白质酪氨酸磷酸酶(protein tyrosine phos-phatase receptor type O, PTPRO)表达. 结论 紫花牡荆素对食管鳞癌细胞恶性转移能力有明显的抑制作用,下调VEGF、MMP2与MMP9表达,上调E-cadherin、CDK10与PTPRO可能是其抑制转移的分子机制.%Objective To investigate the depressive effect of Casticin on malignant metastasis of human esopha-gus squamous cell carcinoma ( ESCC ) cells and to analyze its molecular mechanisms. Methods The EC9706 and EC109 cells in ESCC cell line were treated with Casticin, and then the thiazolyl blue ( MTT) colorimetry was used to de-tect cell abilities of proliferation, invasion and migration, and related protein expressions were detected using Western blot method. Results EC9706 and EC109 cells abilities of proliferation, invasion and migration were significantly inhib-ited after different concentrations of Casticin treatment, and the differences were statistically significant compared with those without Casticin treatment (P<0. 05);after the Casticin treatment, the expressions of vascular endothelial growth factor (VEGF), matrix

  3. Engineering molecular mechanics: an efficient static high temperature molecular simulation technique.

    Science.gov (United States)

    Subramaniyan, Arun K; Sun, C T

    2008-07-16

    Inspired by the need for an efficient molecular simulation technique, we have developed engineering molecular mechanics (EMM) as an alternative molecular simulation technique to model high temperature (T>0 K) phenomena. EMM simulations are significantly more computationally efficient than conventional techniques such as molecular dynamics simulations. The advantage of EMM is achieved by converting the dynamic atomistic system at high temperature (T>0 K) into an equivalent static system. Fundamentals of the EMM methodology are derived using thermal expansion to modify the interatomic potential. Temperature dependent interatomic potentials are developed to account for the temperature effect. The efficiency of EMM simulations is demonstrated by simulating the temperature dependence of elastic constants of copper and nickel and the thermal stress developed in a confined copper system.

  4. THE RESEARCH PROGRESSION OF MOLECULAR MECHANISM OFCORRELATION BETWEEN OBESITY AND CANCER%肥胖与癌症相关性的分子机制研究进展

    Institute of Scientific and Technical Information of China (English)

    马强; 李敏; 杨德志; 赵贵君

    2012-01-01

    肥胖是目前威胁全世界人民健康的重大公共卫生问题之一.近年来肥胖相关的肿瘤也成为一个人类主要的健康问题而受到广泛关注.对于肥胖相关肿瘤的危险性因子如胰岛素、胰岛素类生长因子、脂肪因子以及多个细胞内信号通路已有研究.本文综述肥胖引起的危险因子激活PI3K/Akt,MAPK及STAT3通路来促进肿瘤发生发展的分子机制,并对其进一步的研究与防治进行展望.%Recently, obesity has threatens the health of people as one of the major public health problems all over the world. In recent years, obesity-related tumors has become a major human health problem and drawn wide attention. Risk factors of obesity-related tumors, such as insulin, insulin-like growth factors, adipokines, as well as multiple intracellular signaling pathways have been studied. This article reviews the risk factors which activating PI3K/Akt,MAPK and STAT3 signal pathways because of obesity to promote the molecular mechanisms of tumorigenesis, and further research and prophylaxis and treatment.

  5. Multiple breast cancer cell-lines derived from a single tumor differ in their molecular characteristics and tumorigenic potential.

    Directory of Open Access Journals (Sweden)

    Goar Mosoyan

    Full Text Available BACKGROUND: Breast cancer cell lines are widely used tools to investigate breast cancer biology and to develop new therapies. Breast cancer tissue contains molecularly heterogeneous cell populations. Thus, it is important to understand which cell lines best represent the primary tumor and have similarly diverse phenotype. Here, we describe the development of five breast cancer cell lines from a single patient's breast cancer tissue. We characterize the molecular profiles, tumorigenicity and metastatic ability in vivo of all five cell lines and compare their responsiveness to 4-hydroxytamoxifen (4-OHT treatment. METHODS: Five breast cancer cell lines were derived from a single patient's primary breast cancer tissue. Expression of different antigens including HER2, estrogen receptor (ER, CK8/18, CD44 and CD24 was determined by flow cytometry, western blotting and immunohistochemistry (IHC. In addition, a Fluorescent In Situ Hybridization (FISH assay for HER2 gene amplification and p53 genotyping was performed on all cell lines. A xenograft model in nude mice was utilized to assess the tumorigenic and metastatic abilities of the breast cancer cells. RESULTS: We have isolated, cloned and established five new breast cancer cell lines with different tumorigenicity and metastatic abilities from a single primary breast cancer. Although all the cell lines expressed low levels of ER, their growth was estrogen-independent and all had high-levels of expression of mutated non-functional p53. The HER2 gene was rearranged in all cell lines. Low doses of 4-OHT induced proliferation of these breast cancer cell lines. CONCLUSIONS: All five breast cancer cell lines have different antigenic expression profiles, tumorigenicity and organ specific metastatic abilities although they derive from a single tumor. None of the studied markers correlated with tumorigenic potential. These new cell lines could serve as a model for detailed genomic and proteomic analyses to

  6. Clinical and Molecular Characteristics of Post-Colonoscopy Colorectal Cancer

    DEFF Research Database (Denmark)

    Stoffel, Elena M; Erichsen, Rune; Frøslev, Trine;

    2016-01-01

    BACKGROUND AND AIMS: Colonoscopy provides incomplete protection from colorectal cancer (CRC), but determinants of post-colonoscopy CRC are not well understood. We compared clinical features and molecular characteristics of CRCs diagnosed at different time intervals after a previous colonoscopy....... METHODS: We performed a population-based, cross-sectional study of incident CRC cases in Denmark (2007-2011), categorized as post-colonoscopy or detected during diagnostic colonoscopy (in patients with no prior colonoscopy). We compared prevalence of proximal location and DNA mismatch repair deficiency (d...

  7. Molecular Transport Mechanisms for Associating and Solvating Penetrant in Polymers

    Science.gov (United States)

    2007-11-02

    PIB ) at different vapor activities in order to understand complex diffusion mechanisms and probe molecular structures above the glass tranisition. The...the individual diffusion coefficients can be separated and that they are equal to each other for the acetic acid/ PIB system. The values of the...BOH) mixtures in polyisobutylene ( PIB ) was studied at varying mixture compositions. Diffusion coefficients and hydrogen bonding interactions were

  8. Molecular mechanisms in muscular dystrophy: a gene expression profiling study.

    OpenAIRE

    2006-01-01

    The muscular dystrophies are a group of neuromuscular disorders characterized by progres¬sive muscle weakness and wasting. Although the underlying genetic defects of a large number of muscular dystrophies are now know, the molecular mechanisms resulting in the devastating effects of the disease are not yet clear. Furthermore, the muscular dystrophies differ in clinical presentation and severity. The processes responsible for this di¬vergence are largely unknown as well. In this thesis, gene e...

  9. Molecular Composites: Processing, Post-Treatment and Mechanics

    Science.gov (United States)

    1987-07-01

    Mechanical Analyzer was used. 3.2 Articulated Matricies Several isotropic solutions (2.5, 3.0, and 3.2 wt%) were made from PBT36 and ABPBI in MSA at a fixed...built to address this problem. 22 3.3 Thermoplastic Matricies Thermoplastic matrix molecular composites could potentially be melt processed. This would...provide obvious advantages over PBT which is, of course, limited to solution processing. Several candidates were considered for matricies . The only re

  10. Molecular dynamics simulation of nanocrystalline nickel: structure and mechanical properties

    Energy Technology Data Exchange (ETDEWEB)

    Swygenhoven, H. van [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Caro, A. [Comision Nacional de Energia Atomica, San Carlos de Bariloche (Argentina). Centro Atomico Bariloche

    1997-09-01

    Molecular dynamics computer simulations of low temperature elastic and plastic deformation of Ni nanophase samples (3-7 nm) are performed. The samples are polycrystals nucleated from different seeds, with random locations and orientations. Bulk and Young`s modulus, onset of plastic deformation and mechanism responsible for the plastic behaviour are studied and compared with the behaviour of coarse grained samples. (author) 1 fig., 3 refs.

  11. Molecular mechanism of signaling by tumor necrosis factor

    Institute of Scientific and Technical Information of China (English)

    ZHA; Jikun(查纪坤); SHU; Hongbing(舒红兵)

    2002-01-01

    Tumor necrosis factor (TNF) is an important cytokine with multiple biological effects,including cell growth,differentiation,apoptosis,immune regulation and induction of inflammation. The effects of TNF are mediated by two receptors,TNF-R1 and TNF-R2. The major signal transduction pathways triggered by TNF include those that lead to apoptosis,activation of transcription factor NF-??B and protein kinase JNK. This review will discuss the molecular mechanisms of these signaling pathways.

  12. Molecular simulation of the reversible mechanical unfolding of proteins.

    Science.gov (United States)

    Rathore, Nitin; Yan, Qiliang; de Pablo, Juan J

    2004-03-22

    In this work we have combined a Wang-Landau sampling scheme [F. Wang and D. Landau, Phys. Rev. Lett. 86, 2050 (2001)] with an expanded ensemble formalism to yield a simple and powerful method for computing potentials of mean force. The new method is implemented to investigate the mechanical deformation of proteins. Comparisons are made with analytical results for simple model systems such as harmonic springs and Rouse chains. The method is then illustrated on a model 15-residue alanine molecule in an implicit solvent. Results for mechanical unfolding of this oligopeptide are compared to those of steered molecular dynamics calculations.

  13. Molecular mechanism of abnormal aggregation of α-synuclein

    Institute of Scientific and Technical Information of China (English)

    HU HongYua; LIN XiaoJing

    2007-01-01

    The abnormal aggregation of α-synuclein (α-Syn) is thought to be closely associated with Parkinson's disease, but the pathogenesis is still unclear. In this review, we survey the latest development in the molecular mechanism of abnormal α-Syn aggregation, especially in the aspects of the core sequences, aggregation inhibitors, structural transformation and filament morphologies. By exploring the mechanism of α-Syn aggregation, we will have a better understanding of the disease pathogenesis, and develop strategies for preventing and treating this severe disease.

  14. Simulated scaling method for localized enhanced sampling and simultaneous "alchemical" free energy simulations: a general method for molecular mechanical, quantum mechanical, and quantum mechanical/molecular mechanical simulations.

    Science.gov (United States)

    Li, Hongzhi; Fajer, Mikolai; Yang, Wei

    2007-01-14

    A potential scaling version of simulated tempering is presented to efficiently sample configuration space in a localized region. The present "simulated scaling" method is developed with a Wang-Landau type of updating scheme in order to quickly flatten the distributions in the scaling parameter lambdam space. This proposal is meaningful for a broad range of biophysical problems, in which localized sampling is required. Besides its superior capability and robustness in localized conformational sampling, this simulated scaling method can also naturally lead to efficient "alchemical" free energy predictions when dual-topology alchemical hybrid potential is applied; thereby simultaneously, both of the chemically and conformationally distinct portions of two end point chemical states can be efficiently sampled. As demonstrated in this work, the present method is also feasible for the quantum mechanical and quantum mechanical/molecular mechanical simulations.

  15. Molecular imaging for assessment of mesenchymal stem cells mediated breast cancer therapy.

    Science.gov (United States)

    Leng, Liang; Wang, Yuebing; He, Ningning; Wang, Di; Zhao, Qianjie; Feng, Guowei; Su, Weijun; Xu, Yang; Han, Zhongchao; Kong, Deling; Cheng, Zhen; Xiang, Rong; Li, Zongjin

    2014-06-01

    The tumor tropism of mesenchymal stem cells (MSCs) makes them an excellent delivery vehicle used in anticancer therapy. However, the exact mechanisms of MSCs involved in tumor microenvironment are still not well defined. Molecular imaging technologies with the versatility in monitoring the therapeutic effects, as well as basic molecular and cellular processes in real time, offer tangible options to better guide MSCs mediated cancer therapy. In this study, an in situ breast cancer model was developed with MDA-MB-231 cells carrying a reporter system encoding a double fusion (DF) reporter gene consisting of firefly luciferase (Fluc) and enhanced green fluorescent protein (eGFP). In mice breast cancer model, we injected human umbilical cord-derived MSCs (hUC-MSCs) armed with a triple fusion (TF) gene containing the herpes simplex virus truncated thymidine kinase (HSV-ttk), renilla luciferase (Rluc) and red fluorescent protein (RFP) into tumor on day 13, 18, 23 after MDA-MB-231 cells injection. Bioluminescence imaging of Fluc and Rluc provided the real time monitor of tumor cells and hUC-MSCs simultaneously. We found that tumors were significantly inhibited by hUC-MSCs administration, and this effect was enhanced by ganciclovir (GCV) application. To further demonstrate the effect of hUC-MSCs on tumor cells in vivo, we employed the near infrared (NIR) imaging and the results showed that hUC-MSCs could inhibit tumor angiogenesis and increased apoptosis to a certain degree. In conclusion, hUC-MSCs can inhibit breast cancer progression by inducing tumor cell death and suppressing angiogenesis. Moreover, molecular imaging is an invaluable tool in tracking cell delivery and tumor response to hUC-MSCs therapies as well as cellular and molecular processes in tumor.

  16. Computational Reconstruction of NFκB Pathway Interaction Mechanisms during Prostate Cancer.

    Science.gov (United States)

    Börnigen, Daniela; Tyekucheva, Svitlana; Wang, Xiaodong; Rider, Jennifer R; Lee, Gwo-Shu; Mucci, Lorelei A; Sweeney, Christopher; Huttenhower, Curtis

    2016-04-01

    Molecular research in cancer is one of the largest areas of bioinformatic investigation, but it remains a challenge to understand biomolecular mechanisms in cancer-related pathways from high-throughput genomic data. This includes the Nuclear-factor-kappa-B (NFκB) pathway, which is central to the inflammatory response and cell proliferation in prostate cancer development and progression. Despite close scrutiny and a deep understanding of many of its members' biomolecular activities, the current list of pathway members and a systems-level understanding of their interactions remains incomplete. Here, we provide the first steps toward computational reconstruction of interaction mechanisms of the NFκB pathway in prostate cancer. We identified novel roles for ATF3, CXCL2, DUSP5, JUNB, NEDD9, SELE, TRIB1, and ZFP36 in this pathway, in addition to new mechanistic interactions between these genes and 10 known NFκB pathway members. A newly predicted interaction between NEDD9 and ZFP36 in particular was validated by co-immunoprecipitation, as was NEDD9's potential biological role in prostate cancer cell growth regulation. We combined 651 gene expression datasets with 1.4M gene product interactions to predict the inclusion of 40 additional genes in the pathway. Molecular mechanisms of interaction among pathway members were inferred using recent advances in Bayesian data integration to simultaneously provide information specific to biological contexts and individual biomolecular activities, resulting in a total of 112 interactions in the fully reconstructed NFκB pathway: 13 (11%) previously known, 29 (26%) supported by existing literature, and 70 (63%) novel. This method is generalizable to other tissue types, cancers, and organisms, and this new information about the NFκB pathway will allow us to further understand prostate cancer and to develop more effective prevention and treatment strategies.

  17. Molecular Mechanism of Isocupressic Acid Supresses MA-10 Cell Steroidogenesis

    Directory of Open Access Journals (Sweden)

    Kuan-Hao Tsui

    2012-01-01

    Full Text Available Consumption of ponderosa pine needles causes late-term abortions in cattle and is a serious poisonous plant problem in foothill and mountain rangelands. Isocupressic acid (IA is the component of pine needles responsible for the abortifacient effect, its abortifacient effect may be due to inhibition of steroidogenesis. To investigate the more detail molecular mechanism, we used MA-10 cell, which is wild used to investigate molecular mechanism of steroidogenesis, to characterize the molecular mechanisms underlying the actions of IA in more detail. In this report, we focus on the function of IA on important steroidogenic genes, including steroidogenic acute regulatory protein (StAR, cytochrome P450 cholesterol side-chain cleavage (P450scc, and 3β-hydroxysteroid dehydrogenase (3β-HSD. We found that IA does not affect enzyme activities of these genes but inhibits transcription of P450scc and translation of StAR and P450scc through attenuating cAMP-PKA signaling. Thus, steroid productions of cells were suppressed.

  18. Genomic and molecular mechanisms for efficient biodegradation of aromatic dye.

    Science.gov (United States)

    Sun, Su; Xie, Shangxian; Chen, Hu; Cheng, Yanbing; Shi, Yan; Qin, Xing; Dai, Susie Y; Zhang, Xiaoyu; Yuan, Joshua S

    2016-01-25

    Understanding the molecular mechanisms for aromatic compound degradation is crucial for the development of effective bioremediation strategies. We report the discovery of a novel phenomenon for improved degradation of Direct Red 5B azo dye by Irpex lacteus CD2 with lignin as a co-substrate. Transcriptomics analysis was performed to elucidate the molecular mechanisms of aromatic degradation in white rot fungus by comparing dye, lignin, and dye/lignin combined treatments. A full spectrum of lignin degradation peroxidases, oxidases, radical producing enzymes, and other relevant components were up-regulated under DR5B and lignin treatments. Lignin induced genes complemented the DR5B induced genes to provide essential enzymes and redox conditions for aromatic compound degradation. The transcriptomics analysis was further verified by manganese peroxidase (MnP) protein over-expression, as revealed by proteomics, dye decolorization assay by purified MnP and increased hydroxyl radical levels, as indicated by an iron reducing activity assay. Overall, the molecular and genomic mechanisms indicated that effective aromatic polymer degradation requires synergistic enzymes and radical-mediated oxidative reactions to form an effective network of chemical processes. This study will help to guide the development of effective bioremediation and biomass degradation strategies.

  19. Obesity-related colon cancer: dietary factors and their mechanisms of anticancer action.

    Science.gov (United States)

    Zeng, Huawei; Lazarova, Darina L

    2012-02-01

    Overweight/obesity is an epidemic in the US as well as in other developed countries, affecting two-thirds of Americans and an estimated 2.3 billion people worldwide. Obesity increases the risk for Type 2 diabetes, cardiovascular disease and cancer. For example, epidemiological studies have established a strong association between obesity and colon cancer. It is generally accepted that metabolic changes associated with overweight/obesity, particularly abdominal obesity and changes in adipocyte function, contribute to the increased risk of colon cancer. Understanding the mechanisms underlying this association is important for the development of preventive strategies for colon cancer. Part of these preventive strategies may be based on dietary factors, such as vitamins, minerals (e.g. selenium), fibre, phytochemicals and phenolic compounds. These anticancer nutrients may counteract the molecular changes associated with obesity. The present article reviews the evidence that inflammation and insulin resistance induced by obesity are the molecular mediators of the association between obesity and colon cancer. We also evaluate the evidence for the ability of dietary factors to target the obesity-induced changes and, thus, protect against colon cancer.

  20. Molecular structure and elastic properties of thermotropic liquid crystals: Integrated molecular dynamics—Statistical mechanical theory vs molecular field approach

    Science.gov (United States)

    Capar, M. Ilk; Nar, A.; Ferrarini, A.; Frezza, E.; Greco, C.; Zakharov, A. V.; Vakulenko, A. A.

    2013-03-01

    The connection between the molecular structure of liquid crystals and their elastic properties, which control the director deformations relevant for electro-optic applications, remains a challenging objective for theories and computations. Here, we compare two methods that have been proposed to this purpose, both characterized by a detailed molecular level description. One is an integrated molecular dynamics-statistical mechanical approach, where the bulk elastic constants of nematics are calculated from the direct correlation function (DCFs) and the single molecule orientational distribution function [D. A. McQuarrie, Statistical Mechanics (Harper & Row, New York, 1973)]. The latter is obtained from atomistic molecular dynamics trajectories, together with the radial distribution function, from which the DCF is then determined by solving the Ornstein-Zernike equation. The other approach is based on a molecular field theory, where the potential of mean torque experienced by a mesogen in the liquid crystal phase is parameterized according to its molecular surface. In this case, the calculation of elastic constants is combined with the Monte Carlo sampling of single molecule conformations. Using these different approaches, but the same description, at the level of molecular geometry and torsional potentials, we have investigated the elastic properties of the nematic phase of two typical mesogens, 4'-n-pentyloxy-4-cyanobiphenyl and 4'-n-heptyloxy-4-cyanobiphenyl. Both methods yield K3(bend) >K1 (splay) >K2 (twist), although there are some discrepancies in the average elastic constants and in their anisotropy. These are interpreted in terms of the different approximations and the different ways of accounting for the structural properties of molecules in the two approaches. In general, the results point to the role of the molecular shape, which is modulated by the conformational freedom and cannot be fully accounted for by a single descriptor such as the aspect ratio.

  1. An argument for mechanism-based statistical inference in cancer.

    Science.gov (United States)

    Geman, Donald; Ochs, Michael; Price, Nathan D; Tomasetti, Cristian; Younes, Laurent

    2015-05-01

    Cancer is perhaps the prototypical systems disease, and as such has been the focus of extensive study in quantitative systems biology. However, translating these programs into personalized clinical care remains elusive and incomplete. In this perspective, we argue that realizing this agenda—in particular, predicting disease phenotypes, progression and treatment response for individuals—requires going well beyond standard computational and bioinformatics tools and algorithms. It entails designing global mathematical models over network-scale configurations of genomic states and molecular concentrations, and learning the model parameters from limited available samples of high-dimensional and integrative omics data. As such, any plausible design should accommodate: biological mechanism, necessary for both feasible learning and interpretable decision making; stochasticity, to deal with uncertainty and observed variation at many scales; and a capacity for statistical inference at the patient level. This program, which requires a close, sustained collaboration between mathematicians and biologists, is illustrated in several contexts, including learning biomarkers, metabolism, cell signaling, network inference and tumorigenesis.

  2. Breast cancer molecular subtypes: from TNBC to QNBC

    Science.gov (United States)

    Hon, Jane Date C; Singh, Baljit; Sahin, Aysegul; Du, Gang; Wang, Jinhua; Wang, Vincent Y; Deng, Fang-Ming; Zhang, David Y; Monaco, Marie E; Lee, Peng

    2016-01-01

    Treatment protocols for breast cancer depend predominantly on receptor status with respect to estrogen (estrogen receptor alpha), progesterone (progesterone receptor) and human epidermal growth factor [human epidermal growth factor receptor 2 (HER2)]. The presence of one or more of these receptors suggests that a treatment targeting these pathways might be effective, while the absence of, or in the case of HER2, lack of overexpression of, all of these receptors, termed triple negative breast cancer (TNBC), indicates a need for the more toxic chemotherapy. In an effort to develop targeted therapies for TNBC, it will be necessary to differentiate among specific TNBC subtypes. The subset of TNBC that expresses androgen receptor (AR) has been determined to express genes consistent with a luminal subtype and therefore may be amenable to therapies targeting either AR, itself, or other pathways typical of a luminal subtype. Recent investigations of the AR signal pathway within breast cancer lead to AR as a significant target for breast cancer therapy with several clinical trials currently in progress. The subclass of TNBC that lacks AR, which we have termed quadruple negative breast cancer (QNBC) currently lacks a defined targetable pathway. Unlike AR-positive TNBC, QNBC predominantly exhibits a basal-like molecular subtype. Several subtypes and related pathway proteins are preferentially expressed in QNBC that may serve as effective targets for treatment, such as ACSL4, SKP2 and EGFR. ACSL4 expression has been demonstrated to be inversely correlated with expression of hormone/growth factor receptors and may thus serve as a biomarker for QNBC as well as a target for therapy. In the following review we summarize some of the current efforts to develop alternatives to chemotherapy for TNBC and QNBC.

  3. Systematic study of imidazoles inhibiting IDO1 via the integration of molecular mechanics and quantum mechanics calculations.

    Science.gov (United States)

    Zou, Yi; Wang, Fang; Wang, Yan; Guo, Wenjie; Zhang, Yihua; Xu, Qiang; Lai, Yisheng

    2017-03-14

    Indoleamine 2,3-dioxygenase 1 (IDO1) is regarded as an attractive target for cancer immunotherapy. To rationalize the detailed interactions between IDO1 and its inhibitors at the atomic level, an integrated computational approach by combining molecular mechanics and quantum mechanics methods was employed in this report. Specifically, the binding modes of 20 inhibitors was initially investigated using the induced fit docking (IFD) protocol, which outperformed other two docking protocols in terms of correctly predicting ligand conformations. Secondly, molecular dynamics (MD) simulations and MM/PBSA free energy calculations were employed to determine the dynamic binding process and crucial residues were confirmed through close contact analysis, hydrogen-bond analysis and binding free energy decomposition calculations. Subsequent quantum mechanics and nonbonding interaction analysis were carried out to provide in-depth explanations on the critical role of those key residues, and Arg231 and 7-propionate of the heme group were major contributors to ligand binding, which lowed a great amount of interaction energy. We anticipate that these findings will be valuable for enzymatic studies and rational drug design.

  4. Spontaneous cancer-stromal cell fusion as a mechanism of prostate cancer androgen-independent progression.

    Directory of Open Access Journals (Sweden)

    Ruoxiang Wang

    Full Text Available We have previously shown that human prostate cancer cells are capable of acquiring malignant attributes through interaction with stromal cells in the tumor microenvironment, while the interacting stromal cells can also become affected with both phenotypic and genotypic alterations. This study used a co-culture model to investigate the mechanism underlying the co-evolution of cancer and stromal cells. Red fluorescent androgen-dependent LNCaP prostate cancer cells were cultured with a matched pair of normal and cancer-associated prostate myofibroblast cells to simulate cancer-stromal interaction, and cellular changes in the co-culture were documented by tracking the red fluorescence. We found frequent spontaneous fusions between cancer and stromal cells throughout the co-culture. In colony formation assays assessing the fate of the hybrid cells, most of the cancer-stromal fusion hybrids remained growth-arrested and eventually perished. However, some of the hybrids survived to form colonies from the co-culture with cancer-associated stromal cells. These derivative clones showed genomic alterations together with androgen-independent phenotype. The results from this study reveal that prostate cancer cells are fusogenic, and cancer-stromal interaction can lead to spontaneous fusion between the two cell types. While a cancer-stromal fusion strategy may allow the stromal compartment to annihilate invading cancer cells, certain cancer-stromal hybrids with increased survival capability may escape annihilation to form a derivative cancer cell population with an altered genotype and increased malignancy. Cancer-stromal fusion thus lays a foundation for an incessant co-evolution between cancer and the cancer-associated stromal cells in the tumor microenvironment.

  5. Role of mismatch in mechanical properties in cancer cell migration

    Science.gov (United States)

    Butcher, Julian; Das, Moumita

    2014-03-01

    Recent experiments suggest that the mechanical stiffness of cells and their interaction with their surroundings undergo remarkable changes during tumor progression. An intriguing experimental result in this area suggests that the mismatch in the elasticity and adhesive properties between cancer cells and cells that have not yet transformed may lead to enhanced cancer cell motility in a binary cell population. Motivated by this, we study the mechanical response and dynamics of a binary system of active and deformable particles using Langevin Dynamics simulations. We characterize their motility by studying particle trajectories, mean square displacements and correlation functions. Our study may provide an understanding of the interplay of mechanical and statistical mechanical properties underlying the enhanced motility of cancer cells during metastasis. This work was partially supported by a D-RIG grant from the College of Science at Rochester Institute of Technology.

  6. The superspreading mechanism unveiled via molecular dynamics simulations

    Science.gov (United States)

    Theodorakis, Panagiotis; Muller, Erich; Craster, Richard; Matar, Omar

    2014-11-01

    Superspreading, by which aqueous droplets laden with specific surfactants wet hydrophobic substrates, is an unusual and dramatic phenomenon. This is attributed to various factors, e.g., a particular surfactant geometry, Marangoni flow, unique solid-fluid interactions, however, direct evidence for a plausible mechanism for superspreading has not yet been provided. Here, we use molecular dynamics simulations of a coarse-grained model with force fields obtained from the SAFT- γ equation of state to capture the superspreading mechanism of water drops with surfactants on model surfaces. Our simulations highlight and monitor the main features of the molecular behavior that lead to the superspreading mechanism, and reproduce and explain the experimentally-observed characteristic maxima of the spreading rate of the droplet vs. surfactant concentration and wettability. We also present a comparison between superspreading and non-superspreading surfactants underlining the main morphological and energetic characteristics of superspreaders. We believe that this is the first time a plausible superspreading mechanism based on a microscopic description is proposed; this will enable the design of surfactants with enhanced spreading ability specifically tailored for applications. EPSRC Grant Number EP/J010502/1.

  7. A mechanically-induced colon cancer cell population shows increased metastatic potential

    KAUST Repository

    Tang, Xin

    2014-05-29

    Background: Metastasis accounts for the majority of deaths from cancer. Although tumor microenvironment has been shown to have a significant impact on the initiation and/or promotion of metastasis, the mechanism remains elusive. We previously reported that HCT-8 colon cancer cells underwent a phenotypic transition from an adhesive epithelial type (E-cell) to a rounded dissociated type (R-cell) via soft substrate culture, which resembled the initiation of metastasis. The objective of current study was to investigate the molecular and metabolic mechanisms of the E-R transition.Methods: Global gene expressions of HCT-8 E and R cells were measured by RNA Sequencing (RNA-seq); and the results were further confirmed by real-time PCR. Reactive oxygen species (ROS), anoikis resistance, enzyme activity of aldehyde dehydrogenase 3 family, member A1 (ALDH3A1), and in vitro invasion assay were tested on both E and R cells. The deformability of HCT-8 E and R cells was measured by atomic force microscopy (AFM). To study the in vivo invasiveness of two cell types, athymic nude mice were intra-splenically injected with HCT-8 E or R cells and sacrificed after 9 weeks. Incidences of tumor development and metastasis were histologically evaluated and analyzed with Fisher\\'s exact test.Results: Besides HCT-8, E-R transition on soft substrates was also seen in three other cancer cell lines (HCT116, SW480 colon and DU145 prostate cancer). The expression of some genes, such as ALDH3A1, TNS4, CLDN2, and AKR1B10, which are known to play important roles in cancer cell migration, invasion, proliferation and apoptosis, were increased in HCT-8 R cells. R cells also showed higher ALDH3A1 enzyme activity, higher ROS, higher anoikis resistance, and higher softness than E cells. More importantly, in vitro assay and in vivo animal models revealed that HCT-8 R cells were more invasive than E cells.Conclusions: Our comprehensive comparison of HCT-8 E and R cells revealed differences of molecular

  8. Comprehensive Molecular Portraits of Invasive Lobular Breast Cancer.

    Science.gov (United States)

    Ciriello, Giovanni; Gatza, Michael L; Beck, Andrew H; Wilkerson, Matthew D; Rhie, Suhn K; Pastore, Alessandro; Zhang, Hailei; McLellan, Michael; Yau, Christina; Kandoth, Cyriac; Bowlby, Reanne; Shen, Hui; Hayat, Sikander; Fieldhouse, Robert; Lester, Susan C; Tse, Gary M K; Factor, Rachel E; Collins, Laura C; Allison, Kimberly H; Chen, Yunn-Yi; Jensen, Kristin; Johnson, Nicole B; Oesterreich, Steffi; Mills, Gordon B; Cherniack, Andrew D; Robertson, Gordon; Benz, Christopher; Sander, Chris; Laird, Peter W; Hoadley, Katherine A; King, Tari A; Perou, Charles M

    2015-10-08

    Invasive lobular carcinoma (ILC) is the second most prevalent histologic subtype of invasive breast cancer. Here, we comprehensively profiled 817 breast tumors, including 127 ILC, 490 ductal (IDC), and 88 mixed IDC/ILC. Besides E-cadherin loss, the best known ILC genetic hallmark, we identified mutations targeting PTEN, TBX3, and FOXA1 as ILC enriched features. PTEN loss associated with increased AKT phosphorylation, which was highest in ILC among all breast cancer subtypes. Spatially clustered FOXA1 mutations correlated with increased FOXA1 expression and activity. Conversely, GATA3 mutations and high expression characterized luminal A IDC, suggesting differential modulation of ER activity in ILC and IDC. Proliferation and immune-related signatures determined three ILC transcriptional subtypes associated with survival differences. Mixed IDC/ILC cases were molecularly classified as ILC-like and IDC-like revealing no true hybrid features. This multidimensional molecular atlas sheds new light on the genetic bases of ILC and provides potential clinical options.

  9. Molecular cytogenetics: an indispensable tool for cancer diagnosis.

    Science.gov (United States)

    Wan, Thomas Sk; Ma, Edmond Sk

    2012-01-01

    Cytogenetic aberrations may escape detection or recognition in traditional karyotyping. The past decade has seen an explosion of methodological advances in molecular cytogenetics technology. These cytogenetics techniques add color to the black and white world of conventional banding. Fluorescence in-situ hybridization (FISH) study has emerged as an indispensable tool for both basic and clinical research, as well as diagnostics, in leukemia and cancers. FISH can be used to identify chromosomal abnormalities through fluorescent labeled DNA probes that target specific DNA sequences. Subsequently, FISH-based tests such as multicolor karyotyping, comparative genomic hybridization (CGH) and array CGH have been used in emerging clinical applications as they enable resolution of complex karyotypic aberrations and whole global scanning of genomic imbalances. More recently, crossspecies array CGH analysis has also been employed in cancer gene identification. The clinical impact of FISH is pivotal, especially in the diagnosis, prognosis and treatment decisions for hematological diseases, all of which facilitate the practice of personalized medicine. This review summarizes the methodology and current utilization of these FISH techniques in unraveling chromosomal changes and highlights how the field is moving away from conventional methods towards molecular cytogenetics approaches. In addition, the potential of the more recently developed FISH tests in contributing information to genetic abnormalities is illustrated.

  10. Molecular profiling of multiple human cancers defines an inflammatory cancer-associated molecular pattern and uncovers KPNA2 as a uniform poor prognostic cancer marker.

    Directory of Open Access Journals (Sweden)

    Saleh M Rachidi

    Full Text Available BACKGROUND: Immune evasion is one of the recognized hallmarks of cancer. Inflammatory responses to cancer can also contribute directly to oncogenesis. Since the immune system is hardwired to protect the host, there is a possibility that cancers, regardless of their histological origins, endow themselves with a common and shared inflammatory cancer-associated molecular pattern (iCAMP to promote oncoinflammation. However, the definition of iCAMP has not been conceptually and experimentally investigated. METHODS AND FINDINGS: Genome-wide cDNA expression data was analyzed for 221 normal and 324 cancer specimens from 7 cancer types: breast, prostate, lung, colon, gastric, oral and pancreatic. A total of 96 inflammatory genes with consistent dysregulation were identified, including 44 up-regulated and 52 down-regulated genes. Protein expression was confirmed by immunohistochemistry for some of these genes. The iCAMP contains proteins whose roles in cancer have been implicated and others which are yet to be appreciated. The clinical significance of many iCAMP genes was confirmed in multiple independent cohorts of colon and ovarian cancer patients. In both cases, better prognosis correlated strongly with high CXCL13 and low level of GREM1, LOX, TNFAIP6, CD36, and EDNRA. An "Inflammatory Gene Integrated Score" was further developed from the combination of 18 iCAMP genes in ovarian cancer, which predicted overall survival. Noticeably, as a selective nuclear import protein whose immuno-regulatory function just begins to emerge, karyopherin alpha 2 (KPNA2 is uniformly up-regulated across cancer types. For the first time, the cancer-specific up-regulation of KPNA2 and its clinical significance were verified by tissue microarray analysis in colon and head-neck cancers. CONCLUSION: This work defines an inflammatory signature shared by seven epithelial cancer types and KPNA2 as a consistently up-regulated protein in cancer. Identification of iCAMP may not only

  11. Mechanisms and treatment of cancer cachexia.

    Science.gov (United States)

    Argilés, J M; López-Soriano, F J; Busquets, S

    2013-12-01

    According to a recent consensus, cachexia is a complex metabolic syndrome associated with underlying illness and characterised by loss of muscle with or without loss of fat mass. The prominent clinical feature of cachexia is weight loss. Cachexia occurs in the majority of terminal cancer patients and it is responsible for the deaths of 22% of cancer patients. Although body weight is, indeed, an important factor to be taken into consideration in any cachexia treatment, body composition, physical performance and quality of life should be monitored. From the results presented here, one can speculate that a single therapy may not be completely successful in the treatment of cachexia. From this point of view, treatments involving different combinations are more likely to be successful. The objectives of any therapeutical combination are two: an anticatabolic aim directed towards both fat and muscle catabolism and an anabolic objective leading to the synthesis of macromolecules such as contractile proteins.

  12. Mechanisms of PCBS-Induced Breast Cancer

    Science.gov (United States)

    1998-09-01

    increase in GST activity. This is because the GST gene has a dioxin response element in its promoter region, which is activated by the Ah receptor complex... biomarkers of carcinogen exposure. The measurement of DNA adducts has important applications for cancer risk assessment. The goal of our work is to...on Halogenated Environmental Organic Pollutants ( DIOXIN 󈨦) (Stockholm, 1998). Organohalogen Compounds 37, 59-62, 1998. Paglia, D.E. and W.N

  13. [Current progress in functions of axon guidance molecule Robo and underlying molecular mechanism].

    Science.gov (United States)

    Li, Xiao-Tong; Zhou, Qi-Sheng; Yu, Qi; Zhao, Xiao; Liu, Qing-Xin

    2014-06-25

    The axon guidance molecule Robo is a transmembrane protein which is conserved during evolution. Robo and its ligand, Slit, have been implicated in regulating many developmental processes, such as axon guidance, neuronal migration, tumor metastasis, angiogenesis, lung morphogenesis, kidney morphogenesis, heart morphogenesis, ovary development and gonad development. Robo function mainly depends on the binding of its Ig1 domain to the LRR-2 domain of Slit ligand. Meanwhile, Robo function is also mediated by binding to some signaling molecules, including the heparan sulfate proteoglycans (HSPGs), GTPase-activating proteins (GAPs) and tyrosine kinase Abelson. Several transcription factors, including Hox, Midline and Nkx2.9, were shown to regulate robo expression. In addition, alternative splicing and transport regulation also affect Robo function. In this review, we summarized the studies on the molecular structure, functions and molecular mechanism of Robo, which would propose a novel strategy for the research of neural development, as well as prevention and treatment of nervous system diseases and cancers.

  14. Mechanism(s of Pancreatic Cancer-induced Diabetes

    Directory of Open Access Journals (Sweden)

    Suresh T Chari

    2014-09-01

    Full Text Available While long-standing diabetes (DM modestly increases the risk of pancreatic ductal adenocarcinoma (PC, there is growing evidence that PC frequently causes DM. Up to 85% of PC patients have DM or hyperglycemia, which frequently manifests in the 2 to 3 years preceding the diagnosis of cancer. Conversely, subjects with new-onset DM have a high probability (5-8 folds higher than the population of being diagnosed with PC within 1-3 years of DM onset. Resection of the PC leads to amelioration of DM. Type 2 DM occurs due to beta cell failure following decades of obesity-associated insulin resistance. As in type 2 DM, beta cell dysfunction and peripheral insulin resistance are seen in PC-induced DM (PC-DM. However, in contrast to type 2 DM, onset and progression of glucose intolerance in PC-DM occur in the face of ongoing, often profound, weight loss. The weight loss precedes the development of DM in PC and occurs months before the onset of cancer cachexia.

  15. Investigation of deformation mechanisms of staggered nanocomposites using molecular dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Mathiazhagan, S., E-mail: smathi.research@gmail.com; Anup, S., E-mail: anupiist@gmail.com

    2016-08-19

    Biological materials with nanostructure of regularly or stair-wise staggered arrangements of hard platelets reinforced in a soft protein matrix have superior mechanical properties. Applications of these nanostructures to ceramic matrix composites could enhance their toughness. Using molecular dynamics simulations, mechanical behaviour of the bio-inspired nanocomposites is studied. Regularly staggered model shows better flow behaviour compared to stair-wise staggered model due to the symmetrical crack propagation along the interface. Though higher stiffness and strength are obtained for stair-wise staggered models, rapid crack propagation reduces the toughness. Arresting this crack propagation could lead to superior mechanical properties in stair-wise staggered models. - Highlights: • The deformation behaviour of staggered nanocomposites is studied. • Stair-wise staggered model has high stiffness and strength, but low toughness. • Rapid crack growth in overlap region causes this low toughness. • Toughness could be enhanced by arresting interfacial crack in the overlap.

  16. T cell mediated pathogenesis in EAE: Molecular mechanisms

    Directory of Open Access Journals (Sweden)

    Florian C Kurschus

    2015-06-01

    Full Text Available T cells are major initiators and mediators of disease in multiple sclerosis (MS and in its animal model experimental autoimmune encephalomyelitis (EAE. EAE is an antigen-driven autoimmune model in which immunization against myelin autoantigens elicits strong T cell responses which initiate its pathology with CNS myelin destruction. T cells cause pathogenic events by several mechanisms; some work in a direct fashion in the CNS, such as direct cytokine-induced damage, granzyme-mediated killing, or glutamate-induced neurotoxicity, whereas most are indirect mechanisms, such as activation of other cell types like macrophages, B cells, or neutrophils. This review aims to describe and discuss the molecular effector mechanism by which T cells harm the CNS during EAE.

  17. Molecular targeted treatment and radiation therapy for rectal cancer

    Energy Technology Data Exchange (ETDEWEB)

    Marquardt, Friederike; Roedel, Franz; Capalbo, Gianni; Weiss, Christian; Roedel, Claus [Dept. of Radiation Therapy, Univ. of Frankfurt/Main (Germany)

    2009-06-15

    Background: EGFR (epidermal growth factor receptor) and VEGF (vascular endothelial growth factor) inhibitors confer clinical benefit in metastatic colorectal cancer when combined with chemotherapy. An emerging strategy to improve outcomes in rectal cancer is to integrate biologically active, targeted agents as triple therapy into chemoradiation protocols. Material and methods: cetuximab and bevacizumab have now been incorporated into phase I-II studies of preoperative chemoradiation therapy (CRT) for rectal cancer. The rationale of these combinations, early efficacy and toxicity data, and possible molecular predictors for tumor response are reviewed. Computerized bibliographic searches of Pubmed were supplemented with hand searches of reference lists and abstracts of ASCO and ASTRO meetings. Results: the combination of cetuximab and CRT can be safely applied without dose compromises of the respective treatment components. Disappointingly low rates of pathologic complete remission have been noted in several phase II studies. The K-ras mutation status and the gene copy number of EGFR may predict tumor response. The toxicity pattern (radiation-induced enteritis, perforations) and surgical complications (wound healing, fistula, bleeding) observed in at least some of the clinical studies with bevacizumab and CRT warrant further investigations. Conclusion: longer follow-up (and, finally, randomized trials) is needed to draw any firm conclusions with respect to local and distant failure rates, and toxicity associated with these novel treatment approaches. (orig.)

  18. Physiological, Molecular and Genetic Mechanisms of Long-Term Habituation

    Energy Technology Data Exchange (ETDEWEB)

    Calin-Jageman, Robert J

    2009-09-12

    Work funded on this grant has explored the mechanisms of long-term habituation, a ubiquitous form of learning that plays a key role in basic cognitive functioning. Specifically, behavioral, physiological, and molecular mechanisms of habituation have been explored using a simple model system, the tail-elicited siphon-withdrawal reflex (T-SWR) in the marine mollusk Aplysia californica. Substantial progress has been made on the first and third aims, providing some fundamental insights into the mechanisms by which memories are stored. We have characterized the physiological correlates of short- and long-term habituation. We found that short-term habituation is accompanied by a robust sensory adaptation, whereas long-term habituation is accompanied by alterations in sensory and interneuron synaptic efficacy. Thus, our data indicates memories can be shifted between different sites in a neural network as they are consolidated from short to long term. At the molecular level, we have accomplished microarray analysis comparing gene expression in both habituated and control ganglia. We have identified a network of putatively regulated transcripts that seems particularly targeted towards synaptic changes (e.g. SNAP25, calmodulin) . We are now beginning additional work to confirm regulation of these transcripts and build a more detailed understanding of the cascade of molecular events leading to the permanent storage of long-term memories. On the third aim, we have fostered a nascent neuroscience program via a variety of successful initiatives. We have funded over 11 undergraduate neuroscience scholars, several of whom have been recognized at national and regional levels for their research. We have also conducted a pioneering summer research program for community college students which is helping enhance access of underrepresented groups to life science careers. Despite minimal progress on the second aim, this project has provided a) novel insight into the network mechanisms by

  19. Studies on the molecular mechanisms of seed germination.

    Science.gov (United States)

    Han, Chao; Yang, Pingfang

    2015-05-01

    Seed germination that begins with imbibition and ends with radicle emergence is the first step for plant growth. Successful germination is not only crucial for seedling establishment but also important for crop yield. After being dispersed from mother plant, seed undergoes continuous desiccation in ecosystem and selects proper environment to trigger germination. Owing to the contribution of transcriptomic, proteomic, and molecular biological studies, molecular aspect of seed germination is elucidated well in Arabidopsis. Recently, more and more proteomic and genetic studies concerning cereal seed germination were performed on rice (Oryza sativa) and barley (Hordeum vulgare), which possess completely different seed structure and domestication background with Arabidopsis. In this review, both the common features and the distinct mechanisms of seed germination are compared among different plant species including Arabidopsis, rice, and maize. These features include morphological changes, cell and its related structure recovery, metabolic activation, hormone behavior, and transcription and translation activation. This review will provide more comprehensive insights into the molecular mechanisms of seed germination.

  20. Influence of low molecular weight heparin on cancer patients’ survival

    Directory of Open Access Journals (Sweden)

    V. V. Ptushkin

    2014-07-01

    Full Text Available There is an evidence of interaction between the hemostasis system and tumor progression factors. It is known that in addition to the fibrin formation and platelets activation, thrombin can influence many cells function interacting with protease-activating receptors including tumor cells. These receptors are involved in the malignant cell phenotype formation (adhesion, proliferation, proteolysis. Thrombin can also affect angiogenesis by stimulating endothelial cells penetration through basal membrane and its migration with new vessels formation. Furthermore, it can cause the release of main neoangiogenesis promoter – vascular endothelial growth factor. All of the above and many other linkages of coagulation and tumor create a theoretical background of possible affecting tumor by regulation of the coagulation activity. Thepromise of this approach is controversial, but there is some clinical and experimental evidence of their effectiveness. The most used group ofdrugs for this purpose was heparins. Several retrospective studies have shown a benefit of low molecular weight heparins (LMWH over unfractionated heparin in cancer patient survival. The appearance of a new heparins group – ultra LMWH are of interest from this point ofview and their possible use in cancer patients. To date bemiparin and semuloparin are used in clinic. Both (bemiparin about 3600 kDa,semuloparin 3000 kDa have substancially reduced molecular weight as compared with the smallest of LMWH – enoxaparin (4600 kDa.Use of bemiparin in patients with small cell lung cancer receiving chemotherapy resulted in increased of 2-year survival rate compared to the control group (68.6 % vs. 29.4 %, p = 0.0042.

  1. Growth Inhibition and Apoptosis Inducing Mechanisms of Curcumin on Human Ovarian Cancer Cell Line A2780

    Institute of Scientific and Technical Information of China (English)

    ZHENG Li-duan; TONG Qiang-song; WU Cui-huan

    2006-01-01

    Objective: To explore the growth inhibition effects and apoptosis inducing mechanisms of curcumin on human ovarian cancer cell line A2780. Methods: After treatment with 10-50 μmol/L curcumin for 6-24 h, the growth activity of A2780 cancer cells were studied by [ 4, 5-dimethylthiazol-2-yl]-2, 5-diphenyItetrazolium bromide (MTT) colorimetry. Cellular apoptosis was inspected by flow cytometery and acridine orange-ethidium bromide fluorescent staining methods. The fragmentation of cellular chromosome DNA was detected by DNA ladder, the ultrastructural change was observed under a transmission electron microscope,and the protein levels of nuclear factor-kappa B (NF-κB, P65) and cysteinyl aspartate specific protease-3 (Caspase-3) in ovarian cancer cells were measured by immunohistochemistry. Results: After treatment with various concentrations of curcumin, the growth inhibition rates of cancer cells reached 62.05%- 89.24%,with sub-G1 peaks appearing on histogram. Part of the cancer cells showed characteristic morphological changes of apoptosis under fluorescence and electron microscopes, and the rate of apoptosis was 21.5 % -33.5%. The protein expression of NF-κB was decreased, while that of Caspase-3 was increased in a timedependent manner. Conclusion: Curcumin could significantly inhibit the growth of human ovarian cancer cells;inducing apoptosis through up-regulating Caspase-3 and down-regulating gene expression of NF-κB is probably one of its molecular mechanisms.

  2. Deciphering Molecular Mechanism Underlying Hypolipidemic Activity of Echinocystic Acid

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    Li Han

    2014-01-01

    Full Text Available Our previous study showed that a triterpene mixture, consisting of echinocystic acid (EA and oleanolic acid (OA at a ratio of 4 : 1, dose-dependently ameliorated the hyperlipidemia and atherosclerosis in rabbits fed with high fat/high cholesterol diets. This study was aimed at exploring the mechanisms underlying antihyperlipidemic effect of EA. Molecular docking simulation of EA was performed using Molegro Virtual Docker (version: 4.3.0 to investigate the potential targets related to lipid metabolism. Based on the molecular docking information, isotope labeling method or spectrophotometry was applied to examine the effect of EA on the activity of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA reductase, acyl-CoA:cholesterol acyltransferase (ACAT, and diacylglycerol acyltransferase (DGAT in rat liver microsomes. Our results revealed a strong affinity of EA towards ACAT and DGAT in molecular docking analysis, while low binding affinity existed between EA and HMG-CoA reductase as well as between EA and cholesteryl ester transfer protein. Consistent with the results of molecular docking, in vitro enzyme activity assays showed that EA inhibited ACAT and DGAT, with IC50 values of 103 and 139 μM, respectively, and exhibited no significant effect on HMG-CoA reductase activity. The present findings suggest that EA may exert hypolipidemic effect by inhibiting the activity of ACAT and DGAT.

  3. Nuclear EGFR as a molecular target in cancer.

    Science.gov (United States)

    Brand, Toni M; Iida, Mari; Luthar, Neha; Starr, Megan M; Huppert, Evan J; Wheeler, Deric L

    2013-09-01

    The epidermal growth factor receptor (EGFR) has been one of the most targeted receptors in the field of oncology. While anti-EGFR inhibitors have demonstrated clinical success in specific cancers, most patients demonstrate either intrinsic or acquired resistance within one year of treatment. Many mechanisms of resistance to EGFR inhibitors have been identified, one of these being attributed to alternatively localized EGFR from the cell membrane into the cell's nucleus. Inside the nucleus, EGFR functions as a co-transcription factor for several genes involved in cell proliferation and angiogenesis, and as a tyrosine kinase to activate and stabilize proliferating cell nuclear antigen and DNA dependent protein kinase. Nuclear localized EGFR is highly associated with disease progression, worse overall survival in numerous cancers, and enhanced resistance to radiation, chemotherapy, and the anti-EGFR therapies gefitinib and cetuximab. In this review the current knowledge of how nuclear EGFR enhances resistance to cancer therapeutics is discussed, in addition to highlighting ways to target nuclear EGFR as an anti-cancer strategy in the future.

  4. The Molecular Mechanism of HDAC Inhibitors in Anticancer Effects

    Institute of Scientific and Technical Information of China (English)

    Gaofeng Bi; Guosheng Jiang

    2006-01-01

    HDACs and HATs are two kinds of enzymes which catalyse deacetylation and acetylation of histone in eukaryotes,whose dynamic balance has accurate regulation for gene transcription and gene expression of eukaryotes at DNA level. Disbalance of them can bring the disorder of proliferation and differentiation in normal cells, and then lead to the initiation of tumor. Their aberrant functions were directly related to the initiation and progression of various tumors, such as promyelocytic leukemia, Hodgkin lymphoma, colonic cancer and gastral cancer. The inhibitors of HDACs are used for treatment of tumor. They can restrain the activity of HDACs and block the inhibition of gene expression caused by the disorder of deacetylation. Its major biological effects lie in inducing differentiation of tumor cells, arresting cell circle at G0/G1, activating cell apoptosis gene, enhancing the sensitivity of chemical therapy and radioactive therapy. So far HDAC has been an important target enzyme in anticancer drug research.Cellular & Molecular Immunology. 2006;3(4):285-290.

  5. The lipid-reactive oxygen species phenotype of breast cancer. Raman spectroscopy and mapping, PCA and PLSDA for invasive ductal carcinoma and invasive lobular carcinoma. Molecular tumorigenic mechanisms beyond Warburg effect.

    Science.gov (United States)

    Surmacki, Jakub; Brozek-Pluska, Beata; Kordek, Radzislaw; Abramczyk, Halina

    2015-04-01

    Vibrational signatures of human breast tissue (invasive ductal carcinoma and invasive lobular carcinoma) were used to identify, characterize and discriminate structures in normal (noncancerous) and cancerous tissues by confocal Raman imaging, Raman spectroscopy and IR spectroscopy. The most important differences between normal and cancerous tissues were found in regions characteristic for vibrations of carotenoids, fatty acids, proteins, and interfacial water. Particular attention was paid to the role played by unsaturated fatty acids and their derivatives. K-means clustering and basis analysis followed by PCA and PLSDA is employed to analyze Raman spectroscopic maps of human breast tissue and for a statistical analysis of the samples (82 patients, 164 samples). Raman maps successfully identify regions of carotenoids, fatty acids, and proteins. The intensities, frequencies and profiles of the average Raman spectra differentiate the biochemical composition of normal and cancerous tissues. The paper demonstrates that Raman imaging has reached a clinically relevant level in regard to breast cancer diagnosis applications. The sensitivity and specificity obtained directly from PLSLD and cross validation are equal to 90.5% and 84.8% for calibration and 84.7% and 71.9% for cross-validation respectively.

  6. Alterations in cancer cell mechanical properties after fluid shear stress exposure: a micropipette aspiration study

    Directory of Open Access Journals (Sweden)

    Chivukula VK

    2015-01-01

    Full Text Available Venkat Keshav Chivukula,1 Benjamin L Krog,1,2 Jones T Nauseef,2 Michael D Henry,2 Sarah C Vigmostad1 1Department of Biomedical Engineering, 2Department of Molecular Physiology and Biophysics, Holden Comprehensive Cancer Center, University of Iowa, Seamans Center for the Engineering Arts and Sciences, Iowa City, IA, USA Abstract: Over 90% of cancer deaths result not from primary tumor development, but from metastatic tumors that arise after cancer cells circulate to distal sites via the circulatory system. While it is known that metastasis is an inefficient process, the effect of hemodynamic parameters such as fluid shear stress (FSS on the viability and efficacy of metastasis is not well understood. Recent work has shown that select cancer cells may be able to survive and possibly even adapt to FSS in vitro. The current research seeks to characterize the effect of FSS on the mechanical properties of suspended cancer cells in vitro. Nontransformed prostate epithelial cells (PrEC LH and transformed prostate cancer cells (PC-3 were used in this study. The Young's modulus was determined using micropipette aspiration. We examined cells in suspension but not exposed to FSS (unsheared and immediately after exposure to high (6,400 dyn/cm2 and low (510 dyn/cm2 FSS. The PrEC LH cells were ~140% stiffer than the PC-3 cells not exposed to FSS. Post-FSS exposure, there was an increase of ~77% in Young's modulus after exposure to high FSS and a ~47% increase in Young's modulus after exposure to low FSS for the PC-3 cells. There was no significant change in the Young's modulus of PrEC LH cells post-FSS exposure. Our findings indicate that cancer cells adapt to FSS, with an increased Young's modulus being one of the adaptive responses, and that this adaptation is specific only to PC-3 cells and is not seen in PrEC LH cells. Moreover, this adaptation appears to be graded in response to the magnitude of FSS experienced by the cancer cells. This is the first study

  7. Providing a molecular mechanism for P-glycoprotein; why would I bother?

    Science.gov (United States)

    Callaghan, Richard

    2015-10-01

    It is almost 40 years since the drug efflux pump P-glycoprotein (permeability glycoprotein or P-gp) was shown to confer multi-drug resistance in cancer cells. This protein has been one of the most extensively investigated transport proteins due to its intriguing mechanism and its affect in oncology. P-gp is known to interact with over 300 compounds and the ability to achieve this has not yet been revealed. Following the binding of substrate and nucleotide, a complex series of conformational changes in the membrane and cytosolic domains translocates substrate across the membrane. Despite over 30 years of biochemical investigation, the availability of structural data and a plethora of chemical tools to modulate its function, the molecular mechanism remains a mystery. In addition, overcoming its activity in resistant cancer cells has not been achieved in the clinic, thereby garnering some degree of pessimism in the field. This review highlights the progress that has been achieved in understanding this complex protein and the value of undertaking molecular studies.

  8. Combined quantum mechanics/molecular mechanics (QM/MM) methods in computational enzymology.

    Science.gov (United States)

    van der Kamp, Marc W; Mulholland, Adrian J

    2013-04-23

    Computational enzymology is a rapidly maturing field that is increasingly integral to understanding mechanisms of enzyme-catalyzed reactions and their practical applications. Combined quantum mechanics/molecular mechanics (QM/MM) methods are important in this field. By treating the reacting species with a quantum mechanical method (i.e., a method that calculates the electronic structure of the active site) and including the enzyme environment with simpler molecular mechanical methods, enzyme reactions can be modeled. Here, we review QM/MM methods and their application to enzyme-catalyzed reactions to investigate fundamental and practical problems in enzymology. A range of QM/MM methods is available, from cheaper and more approximate methods, which can be used for molecular dynamics simulations, to highly accurate electronic structure methods. We discuss how modeling of reactions using such methods can provide detailed insight into enzyme mechanisms and illustrate this by reviewing some recent applications. We outline some practical considerations for such simulations. Further, we highlight applications that show how QM/MM methods can contribute to the practical development and application of enzymology, e.g., in the interpretation and prediction of the effects of mutagenesis and in drug and catalyst design.

  9. Phenethyl isothiocyanate: a comprehensive review of anti-cancer mechanisms.

    Science.gov (United States)

    Gupta, Parul; Wright, Stephen E; Kim, Sung-Hoon; Srivastava, Sanjay K

    2014-12-01

    The epidemiological evidence suggests a strong inverse relationship between dietary intake of cruciferous vegetables and the incidence of cancer. Among other constituents of cruciferous vegetables, isothiocyanates (ITC) are the main bioactive chemicals present. Phenethyl isothiocyanate (PEITC) is present as gluconasturtiin in many cruciferous vegetables with remarkable anti-cancer effects. PEITC is known to not only prevent the initiation phase of carcinogenesis process but also to inhibit the progression of tumorigenesis. PEITC targets multiple proteins to suppress various cancer-promoting mechanisms such as cell proliferation, progression and metastasis. Pre-clinical evidence suggests that combination of PEITC with conventional anti-cancer agents is also highly effective in improving overall efficacy. Based on accumulating evidence, PEITC appears to be a promising agent for cancer therapy and is already under clinical trials for leukemia and lung cancer. This is the first review which provides a comprehensive analysis of known targets and mechanisms along with a critical evaluation of PEITC as a future anti-cancer agent.

  10. Complement system part I - molecular mechanisms of activation and regulation

    Directory of Open Access Journals (Sweden)

    Nicolas eMerle

    2015-06-01

    Full Text Available Complement is a complex innate immune surveillance system, playing a key role in defense against pathogens and in host homeostasis. The complement system is initiated by conformational changes in recognition molecular complexes upon sensing danger signals. The subsequent cascade of enzymatic reactions is tightly regulated to assure that complement is activated only at specific locations requiring defense against pathogens, thus avoiding host tissue damage. Here we discuss the recent advances describing the molecular and structural basis of activation and regulation of the complement pathways and their implication on physiology and pathology. This article will review the mechanisms of activation of alternative, classical and lectin pathways, the formation of C3 and C5 convertases, the action of anaphylatoxins and the membrane attack complex. We will also discuss the importance of structure-function relationships using the example of atypical hemolytic uremic syndrome. Lastly we will discuss the development and benefits of therapies using complement inhibitors.

  11. Neural tube closure: cellular, molecular and biomechanical mechanisms.

    Science.gov (United States)

    Nikolopoulou, Evanthia; Galea, Gabriel L; Rolo, Ana; Greene, Nicholas D E; Copp, Andrew J

    2017-02-15

    Neural tube closure has been studied for many decades, across a range of vertebrates, as a paradigm of embryonic morphogenesis. Neurulation is of particular interest in view of the severe congenital malformations - 'neural tube defects' - that result when closure fails. The process of neural tube closure is complex and involves cellular events such as convergent extension, apical constriction and interkinetic nuclear migration, as well as precise molecular control via the non-canonical Wnt/planar cell polarity pathway, Shh/BMP signalling, and the transcription factors Grhl2/3, Pax3, Cdx2 and Zic2. More recently, biomechanical inputs into neural tube morphogenesis have also been identified. Here, we review these cellular, molecular and biomechanical mechanisms involved in neural tube closure, based on studies of various vertebrate species, focusing on the most recent advances in the field.

  12. Mechanisms of Helicobacter pylori antibiotic resistance and molecular testing

    Directory of Open Access Journals (Sweden)

    Toshihiro eNishizawa

    2014-10-01

    Full Text Available Antibiotic resistance in Helicobacter pylori (H. pylori is the main factor affecting the efficacy of current treatment methods against infection caused by this organism. The traditional culture methods for testing bacterial susceptibility to antibiotics are expensive and require 10 to 14 days. Since resistance to clarithromycin, fluoroquinolone, and tetracycline seems to be exclusively caused by specific mutations in a small region of the responsible gene, molecular methods offer an attractive alternative to the above-mentioned techniques. The technique of polymerase chain reaction (PCR is an accurate and rapid method for the detection of mutations that confer antibiotic resistance. This review highlights the mechanisms of antibiotic resistance in H. pylori and the molecular methods for antibiotic susceptibility testing.

  13. The molecular mechanism and physiological role of cytoplasmic streaming.

    Science.gov (United States)

    Tominaga, Motoki; Ito, Kohji

    2015-10-01

    Cytoplasmic streaming occurs widely in plants ranging from algae to angiosperms. However, the molecular mechanism and physiological role of cytoplasmic streaming have long remained unelucidated. Recent molecular genetic approaches have identified specific myosin members (XI-2 and XI-K as major and XI-1, XI-B, and XI-I as minor motive forces) for the generation of cytoplasmic streaming among 13 myosin XIs in Arabidopsis thaliana. Simultaneous knockout of these myosin XI members led to a reduced velocity of cytoplasmic streaming and marked defects of plant development. Furthermore, the artificial modifications of myosin XI-2 velocity changed plant and cell sizes along with the velocity of cytoplasmic streaming. Therefore, we assume that cytoplasmic streaming is one of the key regulators in determining plant size.

  14. Molecular Mechanisms of Bone Metastasis: Which Targets Came from the Bench to the Bedside?

    Directory of Open Access Journals (Sweden)

    Sandra Casimiro

    2016-08-01

    Full Text Available Bone metastases ultimately result from a complex interaction between cancer cells and bone microenvironment. However, prior to the colonization of the bone, cancer cells must succeed through a series of steps that will allow them to detach from the primary tumor, enter into circulation, recognize and adhere to specific endothelium, and overcome dormancy. We now know that as important as the metastatic cascade, tumor cells prime the secondary organ microenvironment prior to their arrival, reflecting the existence of specific metastasis-initiating cells in the primary tumor and circulating osteotropic factors. The deep comprehension of the molecular mechanisms of bone metastases may allow the future development of specific anti-tumoral therapies, but so far the approved and effective therapies for bone metastatic disease are mostly based in bone-targeted agents, like bisphosphonates, denosumab and, for prostate cancer, radium-223. Bisphosphonates and denosumab have proven to be effective in blocking bone resorption and decreasing morbidity; furthermore, in the adjuvant setting, these agents can decrease bone relapse after breast cancer surgery in postmenopausal women. In this review, we will present and discuss some examples of applied knowledge from the bench to the bed side in the field of bone metastasis.

  15. ACK1/TNK2 tyrosine kinase: molecular signaling and evolving role in cancers.

    Science.gov (United States)

    Mahajan, K; Mahajan, N P

    2015-08-01

    Deregulated tyrosine kinase signaling alters cellular homeostasis to drive cancer progression. The emergence of a non-receptor tyrosine kinase (non-RTK), ACK1 (also known as activated Cdc42-associated kinase 1 or TNK2) as an oncogenic kinase, has uncovered novel mechanisms by which tyrosine kinase signaling promotes cancer progression. Although early studies focused on ACK1 as a cytosolic effector of activated transmembrane RTKs, wherein it shuttles between the cytosol and the nucleus to rapidly transduce extracellular signals from the RTKs to the intracellular effectors, recent data unfold a new aspect of its functionality as an epigenetic regulator. ACK1 interacts with the estrogen receptor (ER)/histone demethylase KDM3A (JHDM2a) complex, which modifies KDM3A by tyrosine phosphorylation to regulate the transcriptional outcome at HOXA1 locus to promote the growth of tamoxifen-resistant breast cancer. It is also well established that ACK1 regulates the activity of androgen receptor (AR) by tyrosine phosphorylation to fuel the growth of hormone-refractory prostate cancers. Further, recent explosion in genomic sequencing has revealed recurrent ACK1 gene amplification and somatic mutations in a variety of human malignancies, providing a molecular basis for its role in neoplastic transformation. In this review, we will discuss the various facets of ACK1 signaling, including its newly uncovered epigenetic regulator function, which enables cells to bypass the blockade to major survival pathways to promote resistance to standard cancer treatments. Not surprisingly, cancer cells appear to acquire an 'addiction' to ACK1-mediated survival, particularly under stress conditions, such as growth factor deprivation or genotoxic insults or hormone deprivation. With the accelerated development of potent and selective ACK1 inhibitors, targeted treatment for cancers harboring aberrant ACK1 activity may soon become a clinical reality.

  16. Molecular-dynamics study of detonation. II. The reaction mechanism

    Science.gov (United States)

    Rice, Betsy M.; Mattson, William; Grosh, John; Trevino, S. F.

    1996-01-01

    In this work, we investigate mechanisms of chemical reactions that sustain an unsupported detonation. The chemical model of an energetic crystal used in this study consists of heteronuclear diatomic molecules that, at ambient pressure, dissociate endothermically. Subsequent association of the products to form homonuclear diatomic molecules provides the energy release that sustains the detonation. A many-body interaction is used to simulate changes in the electronic bonding as a function of local atomic environment. The consequence of the many-body interaction in this model is that the intramolecular bond is weakened with increasing density. The mechanism of the reaction for this model was extracted by investigating the details of the molecular properties in the reaction zone with two-dimensional molecular dynamics. The mechanism for the initiation of the reaction in this model is pressure-induced atomization. There was no evidence of excitation of vibrational modes to dissociative states. This particular result is directly attributable to the functional form and choice of parameters for this model, but might also have more general applicability.

  17. Molecular mechanisms underlying noncoding risk variations in psychiatric genetic studies.

    Science.gov (United States)

    Xiao, X; Chang, H; Li, M

    2017-01-03

    Recent large-scale genetic approaches such as genome-wide association studies have allowed the identification of common genetic variations that contribute to risk architectures of psychiatric disorders. However, most of these susceptibility variants are located in noncoding genomic regions that usually span multiple genes. As a result, pinpointing the precise variant(s) and biological mechanisms accounting for the risk remains challenging. By reviewing recent progresses in genetics, functional genomics and neurobiology of psychiatric disorders, as well as gene expression analyses of brain tissues, here we propose a roadmap to characterize the roles of noncoding risk loci in the pathogenesis of psychiatric illnesses (that is, identifying the underlying molecular mechanisms explaining the genetic risk conferred by those genomic loci, and recognizing putative functional causative variants). This roadmap involves integration of transcriptomic data, epidemiological and bioinformatic methods, as well as in vitro and in vivo experimental approaches. These tools will promote the translation of genetic discoveries to physiological mechanisms, and ultimately guide the development of preventive, therapeutic and prognostic measures for psychiatric disorders.Molecular Psychiatry advance online publication, 3 January 2017; doi:10.1038/mp.2016.241.

  18. Molecular mechanical properties of short-sequence peptide enzyme mimics.

    Science.gov (United States)

    Takahashi, Tsukasa; Vo Ngo, Bao C; Xiao, Leyang; Arya, Gaurav; Heller, Michael J

    2016-01-01

    While considerable attempts have been made to recreate the high turnover rates of enzymes using synthetic enzyme mimics, most have failed and only a few have produced minimal reaction rates that can barely be considered catalytic. One particular approach we have focused on is the use of short-sequence peptides that contain key catalytic groups in close proximity. In this study, we designed six different peptides and tested their ability to mimic the catalytic mechanism of the cysteine proteases. Acetylation and deacylation by Ellman's Reagent trapping experiments showed the importance of having phenylalanine groups surrounding the catalytic sites in order to provide greater proximity between the cysteine, histidine, and aspartate amino acid R-groups. We have also carried out all-atom molecular dynamics simulations to determine the distance between these catalytic groups and the overall mechanical flexibility of the peptides. We found strong correlations between the magnitude of fluctuations in the Cys-His distance, which determines the flexibility and interactions between the cysteine thiol and histidine imidazole groups, and the deacylation rate. We found that, in general, shorter Cys-His distance fluctuations led to a higher deacylation rate constant, implying that greater confinement of the two residues will allow a higher frequency of the acetyl exchange between the cysteine thiol and histidine imidazole R-groups. This may be the key to future design of peptide structures with molecular mechanical properties that lead to viable enzyme mimics.

  19. High-molecular-mass hyaluronan mediates the cancer resistance of the naked mole rat.

    Science.gov (United States)

    Tian, Xiao; Azpurua, Jorge; Hine, Christopher; Vaidya, Amita; Myakishev-Rempel, Max; Ablaeva, Julia; Mao, Zhiyong; Nevo, Eviatar; Gorbunova, Vera; Seluanov, Andrei

    2013-07-18

    The naked mole rat (Heterocephalus glaber) displays exceptional longevity, with a maximum lifespan exceeding 30 years. This is the longest reported lifespan for a rodent species and is especially striking considering the small body mass of the naked mole rat. In comparison, a similarly sized house mouse has a maximum lifespan of 4 years. In addition to their longevity, naked mole rats show an unusual resistance to cancer. Multi-year observations of large naked mole-rat colonies did not detect a single incidence of cancer. Here we identify a mechanism responsible for the naked mole rat's cancer resistance. We found that naked mole-rat fibroblasts secrete extremely high-molecular-mass hyaluronan (HA), which is over five times larger than human or mouse HA. This high-molecular-mass HA accumulates abundantly in naked mole-rat tissues owing to the decreased activity of HA-degrading enzymes and a unique sequence of hyaluronan synthase 2 (HAS2). Furthermore, the naked mole-rat cells are more sensitive to HA signalling, as they have a higher affinity to HA compared with mouse or human cells. Perturbation of the signalling pathways sufficient for malignant transformation of mouse fibroblasts fails to transform naked mole-rat cells. However, once high-molecular-mass HA is removed by either knocking down HAS2 or overexpressing the HA-degrading enzyme, HYAL2, naked mole-rat cells become susceptible to malignant transformation and readily form tumours in mice. We speculate that naked mole rats have evolved a higher concentration of HA in the skin to provide skin elasticity needed for life in underground tunnels. This trait may have then been co-opted to provide cancer resistance and longevity to this species.

  20. High molecular weight hyaluronan mediates the cancer resistance of the naked mole-rat

    Science.gov (United States)

    Tian, Xiao; Azpurua, Jorge; Hine, Christopher; Vaidya, Amita; Myakishev-Rempel, Max; Ablaeva, Julia; Mao, Zhiyong; Nevo, Eviatar; Gorbunova, Vera; Seluanov, Andrei

    2013-01-01

    The naked mole-rat displays exceptional longevity, with a maximum lifespan exceeding 30 years1–3. This is the longest reported lifespan for a rodent species and is especially striking considering the small body mass of the naked mole-rat. In comparison, a similarly sized house mouse has a maximum lifespan of 4 years4,5. In addition to their longevity, naked mole-rats show an unusual resistance to cancer. Multi-year observations of large naked mole-rat colonies did not detect a single incidence of cancer2,6. Here we identify a mechanism responsible for the naked mole-rat’s cancer resistance. We found that naked mole-rat fibroblasts secrete extremely high molecular weight hyaluronan (HA), which is over five times larger than human or mouse HA. This high molecular weight HA accumulates abundantly in naked mole rat tissues due to the decreased activity of HA-degrading enzymes and a unique sequence of hyaluronan synthase 2 (HAS2). Furthermore, the naked mole-rat cells are more sensitive to HA signaling, as the naked mole rat cells have a higher affinity to HA than the mouse or human cells. Perturbation of the signaling pathways sufficient for malignant transformation of mouse fibroblasts fails to transform naked mole-rat cells. However, once high molecular weight HA is removed by either knocking down HAS2 or overexpressing the HA-degrading enzyme, Hyal2, naked mole-rat cells become susceptible to malignant transformation and readily form tumors in mice. We speculate that naked mole-rats have evolved a higher concentration of HA in the skin to provide skin elasticity needed for life in underground tunnels. This trait may have then been co-opted to provide cancer resistance and longevity to this species. PMID:23783513

  1. Common molecular pathways involved in human CD133+/CD34+ progenitor cell expansion and cancer

    Directory of Open Access Journals (Sweden)

    Vêncio Ricardo Z

    2007-06-01

    Full Text Available Abstract Background Uncovering the molecular mechanism underlying expansion of hematopoietic stem and progenitor cells is critical to extend current therapeutic applications and to understand how its deregulation relates to leukemia. The characterization of genes commonly relevant to stem/progenitor cell expansion and tumor development should facilitate the identification of novel therapeutic targets in cancer. Methods CD34+/CD133+ progenitor cells were purified from human umbilical cord blood and expanded in vitro. Correlated molecular changes were analyzed by gene expression profiling using microarrays covering up to 55,000 transcripts. Genes regulated during progenitor cell expansion were identified and functionally classified. Aberrant expression of such genes in cancer was indicated by in silico SAGE. Differential expression of selected genes was assessed by real-time PCR in hematopoietic cells from chronic myeloid leukemia patients and healthy individuals. Results Several genes and signaling pathways not previously associated with ex vivo expansion of CD133+/CD34+ cells were identified, most of which associated with cancer. Regulation of MEK/ERK and Hedgehog signaling genes in addition to numerous proto-oncogenes was detected during conditions of enhanced progenitor cell expansion. Quantitative real-time PCR analysis confirmed down-regulation of several newly described cancer-associated genes in CD133+/CD34+ cells, including DOCK4 and SPARCL1 tumor suppressors, and parallel results were verified when comparing their expression in cells from chronic myeloid leukemia patients Conclusion Our findings reveal potential molecular targets for oncogenic transformation in CD133+/CD34+ cells and strengthen the link between deregulation of stem/progenitor cell expansion and the malignant process.

  2. United polarizable multipole water model for molecular mechanics simulation

    Energy Technology Data Exchange (ETDEWEB)

    Qi, Rui; Wang, Qiantao; Ren, Pengyu, E-mail: pren@mail.utexas.edu [Department of Biomedical Engineering, The University of Texas at Austin, Austin, Texas 78712 (United States); Wang, Lee-Ping; Pande, Vijay S. [Department of Chemistry, Stanford University, Stanford, California 94305 (United States)

    2015-07-07

    We report the development of a united AMOEBA (uAMOEBA) polarizable water model, which is computationally 3–5 times more efficient than the three-site AMOEBA03 model in molecular dynamics simulations while providing comparable accuracy for gas-phase and liquid properties. In this coarse-grained polarizable water model, both electrostatic (permanent and induced) and van der Waals representations have been reduced to a single site located at the oxygen atom. The permanent charge distribution is described via the molecular dipole and quadrupole moments and the many-body polarization via an isotropic molecular polarizability, all located at the oxygen center. Similarly, a single van der Waals interaction site is used for each water molecule. Hydrogen atoms are retained only for the purpose of defining local frames for the molecular multipole moments and intramolecular vibrational modes. The parameters have been derived based on a combination of ab initio quantum mechanical and experimental data set containing gas-phase cluster structures and energies, and liquid thermodynamic properties. For validation, additional properties including dimer interaction energy, liquid structures, self-diffusion coefficient, and shear viscosity have been evaluated. The results demonstrate good transferability from the gas to the liquid phase over a wide range of temperatures, and from nonpolar to polar environments, due to the presence of molecular polarizability. The water coordination, hydrogen-bonding structure, and dynamic properties given by uAMOEBA are similar to those derived from the all-atom AMOEBA03 model and experiments. Thus, the current model is an accurate and efficient alternative for modeling water.

  3. Molecular mechanisms in autoimmune type 1 diabetes: a critical review.

    Science.gov (United States)

    Xie, Zhiguo; Chang, Christopher; Zhou, Zhiguang

    2014-10-01

    Autoimmune type 1 diabetes is characterized by selective destruction of insulin-secreting beta cells in the pancreas of genetically susceptible individuals. The mechanisms underlying the development of type 1 diabetes are not fully understood. However, a widely accepted point is that type 1 diabetes is caused by a combination of genetic and environmental factors. Although most type 1 diabetes patients do not have a family history, genetic susceptibility does play a vital role in beta cell autoimmunity and destruction. Human leukocyte antigen (HLA) regions are the strongest genetic determinants, which can contribute 40-50 % of the genetic risk to type 1 diabetes. Other genes, including INS also contribute to disease risk. The mechanisms of the susceptible genes in type 1 diabetes may relate to their respective roles in antigen presentation, beta cell autoimmunity, immune tolerance, and autoreactive T cell response. Environmental susceptibility factors also contribute to the risk of developing type 1 diabetes. From an epigenetic standpoint, the pathologic mechanisms involved in the development of type 1 diabetes may include DNA methylation, histone modification, microRNA, and molecular mimicry. These mechanisms may act through regulating of gene expression, thereby affecting the immune system response toward islet beta cells. One of the characteristics of type 1 diabetes is the recognition of islet autoantigens by autoreactive CD4(+) and CD8(+) T cells and autoantibodies. Autoantibodies against islet autoantigens are involved in autoantigen processing and presentation by HLA molecules. This review will mainly focus on the molecular mechanism by which genetic, epigenetic, and environmental factors contribute to the risk of type 1 diabetes.

  4. Molecular targets of dietary agents for prevention and therapy of cancer.

    Science.gov (United States)

    Aggarwal, Bharat B; Shishodia, Shishir

    2006-05-14

    While fruits and vegetables are recommended for prevention of cancer and other diseases, their active ingredients (at the molecular level) and their mechanisms of action less well understood. Extensive research during the last half century has identified various molecular targets that can potentially be used not only for the prevention of cancer but also for treatment. However, lack of success with targeted monotherapy resulting from bypass mechanisms has forced researchers to employ either combination therapy or agents that interfere with multiple cell-signaling pathways. In this review, we present evidence that numerous agents identified from fruits and vegetables can interfere with several cell-signaling pathways. The agents include curcumin (turmeric), resveratrol (red grapes, peanuts and berries), genistein (soybean), diallyl sulfide (allium), S-allyl cysteine (allium), allicin (garlic), lycopene (tomato), capsaicin (red chilli), diosgenin (fenugreek), 6-gingerol (ginger), ellagic acid (pomegranate), ursolic acid (apple, pears, prunes), silymarin (milk thistle), anethol (anise, camphor, and fennel), catechins (green tea), eugenol (cloves), indole-3-carbinol (cruciferous vegetables), limonene (citrus fruits), beta carotene (carrots), and dietary fiber. For instance, the cell-signaling pathways inhibited by curcumin alone include NF-kappaB, AP-1, STAT3, Akt, Bcl-2, Bcl-X(L), caspases, PARP, IKK, EGFR, HER2, JNK, MAPK, COX2, and 5-LOX. The active principle identified in fruit and vegetables and the molecular targets modulated may be the basis for how these dietary agents not only prevent but also treat cancer and other diseases. This work reaffirms what Hippocrates said 25 centuries ago, let food be thy medicine and medicine be thy food.

  5. Molecular mechanisms of methicillin resistance in Staphylococcus aureus.

    Science.gov (United States)

    Domínguez, M A; Liñares, J; Martín, R

    1997-09-01

    Methicillin-resistant Staphylococcus aureus (MRSA) strains are among the most common nosocomial pathogens. The most significant mechanism of resistance to methicillin in this-species is the acquisition of a genetic determinant (mecA gene). However, resistance seems to have a more complex molecular basis, since additional chromosomal material is involved in such resistance. Besides, overproduction of penicillinase and/or alterations in the PBPs can contribute to the formation of resistance phenotypes. Genetic and environmental factors leading to MRSA are reviewed.

  6. Buckling of microtubules: An insight by molecular and continuum mechanics

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Jin; Meguid, S. A., E-mail: meguid@mie.utoronto.ca [Mechanics and Aerospace Design Laboratory, Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, Ontario M5S 3G8 (Canada)

    2014-10-27

    The molecular structural mechanics method has been extended to investigate the buckling of microtubules (MTs) with various configurations. The results indicate that for relative short MTs the shear deformation effect, rather than the nonlocal effect, is mainly responsible for the limitation of their widely used Euler beam description and the observed length-dependence of their bending stiffness. In addition, the configuration effect of MTs is also studied and considered as an explanation for the large scattering of the critical buckling force and bending stiffness observed in existing experiments. This configuration effect is also found to mainly originate from the geometry of the MTs and is mainly determined by the protofilament number.

  7. The mechanism of selective molecular capture in carbon nanotube networks.

    Science.gov (United States)

    Wan, Yu; Guan, Jun; Yang, Xudong; Zheng, Quanshui; Xu, Zhiping

    2014-07-28

    Recently, air pollution issues have drawn significant attention to the development of efficient air filters, and one of the most promising materials for this purpose is nanofibers. We explore here the mechanism of selective molecular capture of volatile organic compounds in carbon nanotube networks by performing atomistic simulations. The results are discussed with respect to the two key parameters that define the performance of nanofiltration, i.e. the capture efficiency and flow resistance, which demonstrate the advantages of carbon nanotube networks with high surface-to-volume ratio and atomistically smooth surfaces. We also reveal the important roles of interfacial adhesion and diffusion that govern selective gas transport through the network.

  8. Mouse Low-Grade Gliomas Contain Cancer Stem Cells with Unique Molecular and Functional Properties

    Directory of Open Access Journals (Sweden)

    Yi-Hsien Chen

    2015-03-01

    Full Text Available The availability of adult malignant glioma stem cells (GSCs has provided unprecedented opportunities to identify the mechanisms underlying treatment resistance. Unfortunately, there is a lack of comparable reagents for the study of pediatric low-grade glioma (LGG. Leveraging a neurofibromatosis 1 (Nf1 genetically engineered mouse LGG model, we report the isolation of CD133+ multi-potent low-grade glioma stem cells (LG-GSCs, which generate glioma-like lesions histologically similar to the parent tumor following injection into immunocompetent hosts. In addition, we demonstrate that these LG-GSCs harbor selective resistance to currently employed conventional and biologically targeted anti-cancer agents, which reflect the acquisition of new targetable signaling pathway abnormalities. Using transcriptomic analysis to identify additional molecular properties, we discovered that mouse and human LG-GSCs harbor high levels of Abcg1 expression critical for protecting against ER-stress-induced mouse LG-GSC apoptosis. Collectively, these findings establish that LGG cancer stem cells have unique molecular and functional properties relevant to brain cancer treatment.

  9. Molecular Basis of the Anti-Cancer Effects of Genistein Isoflavone in LNCaP Prostate Cancer Cells.

    Directory of Open Access Journals (Sweden)

    Hartmann J

    2011-03-01

    Full Text Available Background: Prostate cancer is the most common form of non-skin cancer within the United States and the second leading cause of cancer deaths. Survival rates for the advanced disease remain relatively low, and conventional treatments may be accompanied by significant side effects. As a result, current research is aimed at alternative or adjuvant treatments that will target components of the signal transduction, cell-cycle and apoptosis pathways, to induce cell death with little or no toxic side effects to the patient. In this study, we investigated the effect of genistein isoflavone, a soy derivative, on expression levels of genes involved in these pathways. The mechanism of genistein-induced cell death was also investigated. The chemosensitivity of the LNCaP prostate cancer cells to genistein was investigated using ATP and MTS assays, and a caspase binding assay was used to determine apoptosis induction. Several molecular targets were determined using cDNA microarray and RT-PCR analysis.Results: The overall data revealed that genistein induces cell death in a time- and dose-dependent manner, and regulates expression levels of several genes involved in carcinogenesis and immunity. Several cell-cycle genes were down-regulated, including the mitotic kinesins, cyclins and cyclin-dependent kinases. Various members of the Bcl-2 family of apoptotic proteins were also affected. The DefB1 and the HLA membrane receptor genes involved in immunogenicity were also up-regulated.Conclusion: The results indicate that genistein inhibits growth of the hormone-dependent prostate cancer cells, LNCaP, via apoptosis induction through regulation of some of the genes involved in carcinogenesis of many tumors, and immunogenicity. This study augments the potential phytotherapeutic and immunotherapeutic significance of genistein isoflavone.

  10. Molecular and biochemical mechanisms of drug resistance in fungi.

    Science.gov (United States)

    Yamaguchi, H

    1999-01-01

    This paper reviews the current status of our understanding of resistance mechanisms of three major classes of antifungal drugs for systemic use, amphotericin B (AMPH), flucytosine (5-FC) and several azole antifungals, in particular fluconazole (FLCZ), at the molecular and cellular levels. Although the number of reports of AMPH- or 5-FC-resistant fungal species and strains is limited, several mechanisms of resistance have been described. AMPH-resistant Candida have a marked decrease in ergosterol content compared with AMPH-susceptible control isolates. A lesion in the UMP-pyrophosphorylase is the most frequent determinant of 5-FC resistance in C. albicans. Recently resistance of C. albicans to azoles has become an increasing problem. Extensive biochemical studies have highlighted a significant diversity in mechanisms conferring resistance to FLCZ and other azoles, which include alterations in sterol biosynthesis, target site, uptake and efflux. Among them, the most important mechanism clinically is reduced access of the drug to the intracellular P450 14 DM target, probably because of the action of a multidrug resistance efflux pump, and overproduction of that target. However, other possible resistance mechanisms for azoles remain to be identified.

  11. Book Review of "The Molecular Biology of Cancer" by Stella Pelengaris, Michael Khan (Editors

    Directory of Open Access Journals (Sweden)

    Schmidt Christian

    2007-11-01

    Full Text Available Abstract Here, a review of "The Molecular Biology of Cancer" (Stella Pelengaris and Michael Khan [Editors] is given. The detailed description of the book is provided here: Pelengaris S, Khan M (Eds: The Molecular Biology of Cancer; Blackwell Publishing, Oxford (U.K.; 2006. 531 pages, 214 illustrations, ISBN 9-78140-511-814-9, £31.99.

  12. Mechanisms linking dietary fiber, gut microbiota and colon cancer prevention.

    Science.gov (United States)

    Zeng, Huawei; Lazarova, Darina L; Bordonaro, Michael

    2014-02-15

    Many epidemiological and experimental studies have suggested that dietary fiber plays an important role in colon cancer prevention. These findings may relate to the ability of fiber to reduce the contact time of carcinogens within the intestinal lumen and to promote healthy gut microbiota, which modifies the host's metabolism in various ways. Elucidation of the mechanisms by which dietary fiber-dependent changes in gut microbiota enhance bile acid deconjugation, produce short chain fatty acids, and modulate inflammatory bioactive substances can lead to a better understanding of the beneficial role of dietary fiber. This article reviews the current knowledge concerning the mechanisms via which dietary fiber protects against colon cancer.

  13. Estimation of mechanical properties of single wall carbon nanotubes using molecular mechanics approach

    Indian Academy of Sciences (India)

    P Subba Rao; Sunil Anandatheertha; G Narayana Naik; G Gopalakrishnan

    2015-06-01

    Molecular mechanics based finite element analysis is adopted in the current work to evaluate the mechanical properties of Zigzag, Armchair and Chiral Single wall Carbon Nanotubes (SWCNT) of different diameters and chiralities. Three different types of atomic bonds, that is Carbon–Carbon covalent bond and two types of Carbon–Carbon van der Waals bonds are considered in the carbon nanotube system. The stiffness values of these bonds are calculated using the molecular potentials, namely Morse potential function and Lennard-Jones interaction potential function respectively and these stiffness’s are assigned to spring elements in the finite element model of the CNT. The geometry of CNT is built using a macro that is developed for the finite element analysis software. The finite element model of the CNT is constructed, appropriate boundary conditions are applied and the behavior of mechanical properties of CNT is studied.

  14. Redox control of GTPases: from molecular mechanisms to functional significance in health and disease.

    Science.gov (United States)

    Heo, Jongyun

    2011-02-15

    Small GTPases, including the proto-oncoprotein Ras and Rho GTPases, are involved in various cellular signaling events. Some of these small GTPases are redox sensitive, including Ras, Rho, Ran, Dexras1, and Rhes GTPases. Thus, the redox-mediated regulation of these GTPases often determines the course of their cellular signaling cascades. This article takes into consideration the application of Marcus theory to potential redox-based molecular mechanisms in the regulation of these redox-sensitive GTPases and the relevance of such mechanisms to a specific redox-sensitive motif. The discussion also takes into account various diseases, including cancers, heart, and neuronal disorders, that are often linked with the dysregulation of the redox signaling cascades associated with these redox-sensitive GTPases.

  15. Molecular mechanisms underlying the effects of statins in the central nervous system.

    Science.gov (United States)

    McFarland, Amelia J; Anoopkumar-Dukie, Shailendra; Arora, Devinder S; Grant, Gary D; McDermott, Catherine M; Perkins, Anthony V; Davey, Andrew K

    2014-11-10

    3-Hydroxy-3-methylglutaryl coenzyme A reductase inhibitors, commonly referred to as statins, are widely used in the treatment of dyslipidaemia, in addition to providing primary and secondary prevention against cardiovascular disease and stroke. Statins' effects on the central nervous system (CNS), particularly on cognition and neurological disorders such as stroke and multiple sclerosis, have received increasing attention in recent years, both within the scientific community and in the media. Current understanding of statins' effects is limited by a lack of mechanism-based studies, as well as the assumption that all statins have the same pharmacological effect in the central nervous system. This review aims to provide an updated discussion on the molecular mechanisms contributing to statins' possible effects on cognitive function, neurodegenerative disease, and various neurological disorders such as stroke, epilepsy, depression and CNS cancers. Additionally, the pharmacokinetic differences between statins and how these may result in statin-specific neurological effects are also discussed.

  16. Autophagy - Adaptive Molecular Mechanisms in Condition of Starvation

    Directory of Open Access Journals (Sweden)

    Pedrycz Agnieszka

    2015-09-01

    Full Text Available Autophagy is an extremely old process during which long-lived proteins and cellular organelles are removed by means of lysosomes. Autophagy may be caused by cellular stress mechanisms. Research has proven that autophagy plays a key role in obtaining nutrients and adapting to the conditions of starvation. Owing to this, it takes part in maintaining homeostasis in cytoplasm and cell nucleus. This objective may be achieved through a number of ways. Depending on the manner in which a substrate connects with the lysosome, we can talk about macroautophagy and microautophagy. Additionally, some authors also distinguish a chaperone-mediated autophagy. The article presented below describes molecular mechanisms of each type of autophagy and focuses particularly on macroautophagy, which is the best understood of all the autophagy types.

  17. Studies on Molecular Mechanisms Underlying Spinocerebellar Ataxia Type 3

    DEFF Research Database (Denmark)

    Kristensen, Line Vildbrad

    . Even though a range of mechanisms contributing to polyQ diseases have been uncovered, there is still no treatment available. One of the more common polyQ diseases is SCA3, which is caused by a polyQ expansion in the ataxin-3 protein that normally functions as a deubiquitinating enzyme involved...... in protein quality control. In SCA3 patients polyQ expanded ataxin-3 forms intranuclear inclusions in various brain areas, but why the polyQ expansion of ataxin-3 leads to neuronal dysfunction is still not well understood. This thesis describes molecular biological investigations of ataxin-3 biology, aimed...... at furthering our understanding of SCA3 disease mechanisms. In manuscript I, we investigated if post-translational modifications of ataxin-3 were changed by the polyQ expansion. The ubiquitin chain topology and ubiquitination pattern of ataxin-3 were unaltered by the polyQ expansion. In contrast...

  18. Molecular Mechanisms of Two-Component Signal Transduction.

    Science.gov (United States)

    Zschiedrich, Christopher P; Keidel, Victoria; Szurmant, Hendrik

    2016-09-25

    Two-component systems (TCS) comprising sensor histidine kinases and response regulator proteins are among the most important players in bacterial and archaeal signal transduction and also occur in reduced numbers in some eukaryotic organisms. Given their importance to cellular survival, virulence, and cellular development, these systems are among the most scrutinized bacterial proteins. In the recent years, a flurry of bioinformatics, genetic, biochemical, and structural studies have provided detailed insights into many molecular mechanisms that underlie the detection of signals and the generation of the appropriate response by TCS. Importantly, it has become clear that there is significant diversity in the mechanisms employed by individual systems. This review discusses the current knowledge on common themes and divergences from the paradigm of TCS signaling. An emphasis is on the information gained by a flurry of recent structural and bioinformatics studies.

  19. RNA processing-associated molecular mechanisms of neurodegenerative diseases.

    Science.gov (United States)

    Tang, Anna Y

    2016-08-01

    Dysfunctions of RNA processing and mutations of RNA binding proteins (RBPs) play a fundamental role in the pathogenesis of many neurodegenerative diseases. To elucidate the function of RNA processing and RBPs mutations in neuronal cells and to increase our understanding on the pathogenic mechanisms of neurodegeneration, I have reviewed recent advances on RNA processing-associated molecular mechanisms of neurodegenerative diseases, including RBPs-mediated dysfunction of RNA processing, dysfunctional microRNA (miRNA)-based regulation of gene expression, and oxidative RNA modification. I have focused on neurodegeneration induced by RBPs mutations, by dysfunction of miRNA regulation, and by the oxidized RNAs within neurons, and discuss how these dysfunctions have pathologically contributed to neurodegenerative diseases. The advances overviewed above will be valuable to basic investigation and clinical application of target diagnostic tests and therapies.

  20. A molecular understanding of the dynamic mechanism of aquaporin osmosis

    CERN Document Server

    Shua, Liangsuo; Qian, Xin; Wanga, Xiyun; Lin, Yixin; Tan, Kai; Shu, Chaohui; Jin, Shiping

    2014-01-01

    AQPs (aquaporins), the rapid water channels of cells, play a key role in maintaining osmotic equilibrium of cells. In this paper, we reported the dynamic mechanism of AQP osmosis at the molecular level. A theoretical model based on molecular dynamics was carried out and verified by the published experimental data. The reflection coefficients ({\\sigma}) of neutral molecules are mainly decided by their relative size with AQPs, and increase with a third power up to a constant value 1. This model also indicated that the reflection coefficient of a complete impermeable solute can be smaller than 1. The H+ concentration of solution can influence the driving force of the AQPs by changing the equivalent diameters of vestibules surrounded by loops with abundant polar amino acids. In this way, pH of solution can regulate water permeability of AQPs. Therefore, an AQP may not only work as a switch to open or close, but as a rapid response molecular valve to control its water flow. The vestibules can prevent the channel b...