WorldWideScience

Sample records for cell transformations

  1. Characteristics of Mitochondrial Transformation into Human Cells

    Science.gov (United States)

    Kesner, E. E.; Saada-Reich, A.; Lorberboum-Galski, H.

    2016-01-01

    Mitochondria can be incorporated into mammalian cells by simple co-incubation of isolated mitochondria with cells, without the need of transfection reagents or any other type of intervention. This phenomenon was termed mitochondrial transformation, and although it was discovered in 1982, currently little is known regarding its mechanism(s). Here we demonstrate that mitochondria can be transformed into recipient cells very quickly, and co-localize with endogenous mitochondria. The isolated mitochondria interact directly with cells, which engulf the mitochondria with cellular extensions in a way, which may suggest the involvement of macropinocytosis or macropinocytosis-like mechanisms in mitochondrial transformation. Indeed, macropinocytosis inhibitors but not clathrin-mediated endocytosis inhibition-treatments, blocks mitochondria transformation. The integrity of the mitochondrial outer membrane and its proteins is essential for the transformation of the mitochondria into cells; cells can distinguish mitochondria from similar particles and transform only intact mitochondria. Mitochondrial transformation is blocked in the presence of the heparan sulfate molecules pentosan polysulfate and heparin, which indicate crucial involvement of cellular heparan sulfate proteoglycans in the mitochondrial transformation process. PMID:27184109

  2. Characteristics of Mitochondrial Transformation into Human Cells.

    Science.gov (United States)

    Kesner, E E; Saada-Reich, A; Lorberboum-Galski, H

    2016-01-01

    Mitochondria can be incorporated into mammalian cells by simple co-incubation of isolated mitochondria with cells, without the need of transfection reagents or any other type of intervention. This phenomenon was termed mitochondrial transformation, and although it was discovered in 1982, currently little is known regarding its mechanism(s). Here we demonstrate that mitochondria can be transformed into recipient cells very quickly, and co-localize with endogenous mitochondria. The isolated mitochondria interact directly with cells, which engulf the mitochondria with cellular extensions in a way, which may suggest the involvement of macropinocytosis or macropinocytosis-like mechanisms in mitochondrial transformation. Indeed, macropinocytosis inhibitors but not clathrin-mediated endocytosis inhibition-treatments, blocks mitochondria transformation. The integrity of the mitochondrial outer membrane and its proteins is essential for the transformation of the mitochondria into cells; cells can distinguish mitochondria from similar particles and transform only intact mitochondria. Mitochondrial transformation is blocked in the presence of the heparan sulfate molecules pentosan polysulfate and heparin, which indicate crucial involvement of cellular heparan sulfate proteoglycans in the mitochondrial transformation process.

  3. Mechanisms of cell transformation induced by polyomavirus

    Directory of Open Access Journals (Sweden)

    M.L.S. Oliveira

    1999-07-01

    Full Text Available Polyomavirus is a DNA tumor virus that induces a variety of tumors in mice. Its genome encodes three proteins, namely large T (LT, middle T (MT, and small T (ST antigens, that have been implicated in cell transformation and tumorigenesis. LT is associated with cell immortalization, whereas MT plays an essential role in cell transformation by binding to and activating several cytoplasmic proteins that participate in growth factor-induced mitogenic signal transduction to the nucleus. The use of different MT mutants has led to the identification of MT-binding proteins as well as analysis of their importance during cell transformation. Studying the molecular mechanisms of cell transformation by MT has contributed to a better understanding of cell cycle regulation and growth control.

  4. Cell of origin of transformed follicular lymphoma.

    Science.gov (United States)

    Kridel, Robert; Mottok, Anja; Farinha, Pedro; Ben-Neriah, Susana; Ennishi, Daisuke; Zheng, Yvonne; Chavez, Elizabeth A; Shulha, Hennady P; Tan, King; Chan, Fong Chun; Boyle, Merrill; Meissner, Barbara; Telenius, Adele; Sehn, Laurie H; Marra, Marco A; Shah, Sohrab P; Steidl, Christian; Connors, Joseph M; Scott, David W; Gascoyne, Randy D

    2015-10-29

    Follicular lymphoma (FL) is an indolent disease but transforms in 2% to 3% of patients per year into aggressive, large cell lymphoma, a critical event in the course of the disease associated with increased lymphoma-related mortality. Early transformation cannot be accurately predicted at the time of FL diagnosis and the biology of transformed FL (TFL) is poorly understood. Here, we assembled a cohort of 126 diagnostic FL specimens including 40 patients experiencing transformation (transformation for at least 5 years. In addition, we assembled an overlapping cohort of 155 TFL patients, including 114 cases for which paired samples were available, and assessed temporal changes of routinely available biomarkers, outcome after transformation, as well as molecular subtypes of TFL. We report that the expression of IRF4 is an independent predictor of early transformation (Hazard ratio, 13.3; P transformation predicts favorable prognosis. Moreover, applying the Lymph2Cx digital gene expression assay for diffuse large B-cell lymphoma (DLBCL) cell-of-origin determination to 110 patients with DLBCL-like TFL, we demonstrate that TFL is of the germinal-center B-cell-like subtype in the majority of cases (80%) but that a significant proportion of cases is of the activated B-cell-like (ABC) subtype (16%). These latter cases are commonly negative for BCL2 translocation and arise preferentially from BCL2 translocation-negative and/or IRF4-expressing FLs. Our study demonstrates the existence of molecular heterogeneity in TFL as well as its relationship to the antecedent FL. PMID:26307535

  5. Cell of origin of transformed follicular lymphoma.

    Science.gov (United States)

    Kridel, Robert; Mottok, Anja; Farinha, Pedro; Ben-Neriah, Susana; Ennishi, Daisuke; Zheng, Yvonne; Chavez, Elizabeth A; Shulha, Hennady P; Tan, King; Chan, Fong Chun; Boyle, Merrill; Meissner, Barbara; Telenius, Adele; Sehn, Laurie H; Marra, Marco A; Shah, Sohrab P; Steidl, Christian; Connors, Joseph M; Scott, David W; Gascoyne, Randy D

    2015-10-29

    Follicular lymphoma (FL) is an indolent disease but transforms in 2% to 3% of patients per year into aggressive, large cell lymphoma, a critical event in the course of the disease associated with increased lymphoma-related mortality. Early transformation cannot be accurately predicted at the time of FL diagnosis and the biology of transformed FL (TFL) is poorly understood. Here, we assembled a cohort of 126 diagnostic FL specimens including 40 patients experiencing transformation (transformation for at least 5 years. In addition, we assembled an overlapping cohort of 155 TFL patients, including 114 cases for which paired samples were available, and assessed temporal changes of routinely available biomarkers, outcome after transformation, as well as molecular subtypes of TFL. We report that the expression of IRF4 is an independent predictor of early transformation (Hazard ratio, 13.3; P transformation predicts favorable prognosis. Moreover, applying the Lymph2Cx digital gene expression assay for diffuse large B-cell lymphoma (DLBCL) cell-of-origin determination to 110 patients with DLBCL-like TFL, we demonstrate that TFL is of the germinal-center B-cell-like subtype in the majority of cases (80%) but that a significant proportion of cases is of the activated B-cell-like (ABC) subtype (16%). These latter cases are commonly negative for BCL2 translocation and arise preferentially from BCL2 translocation-negative and/or IRF4-expressing FLs. Our study demonstrates the existence of molecular heterogeneity in TFL as well as its relationship to the antecedent FL.

  6. Progressive transformation of immortalized esophageal epithelial cells

    Institute of Scientific and Technical Information of China (English)

    Zhong-YingShen; Li-YanXu; Min-HuaChen; JianShen; Wei-JiaCai; YiZeng

    2002-01-01

    AIM:To investigate the progressive transformation of immortal cells of human fetal esophageal epithelium induced by human papillomavirus,and to examine biological criteria of sequential passage of cells,including cellular phenotype,proliferative rate,telomerase,chromosome and tumorigenicity.

  7. Methionine-sensitive glycolysis in transformed cells.

    Science.gov (United States)

    Boerner, P; Racker, E

    1985-10-01

    Glycolysis in several tumor cell lines grown in tissue culture was inhibited by methionine. Kirsten murine sarcoma virus-transformed rat kidney cells (K-NRK) were inhibited 60-75% by 10 mM methionine, whereas normal rat kidney (NRK-49F) cells showed little or no inhibition. Inhibition of glycolysis in K-NRK cells was manifest 2-4 hr after exposure to the amino acid. Glycolysis in a chemically transformed cell line of Madin-Darby canine kidney cells was also sensitive to methionine, but maximal inhibition (75%) required 18-24 hr of incubation with the amino acid. Under the same conditions glycolysis in the nontransformed canine cells was less than 20% inhibited by methionine. In Ehrlich ascites tumor cells grown in tissue culture, 10 mM methionine inhibited glycolysis by about 50%. Inhibition of glycolysis, even by 50 mM methionine, was rapidly reversible. Within 2 hr after removal of methionine the rate of glycolytic activity was restored to that observed in control cells. Furthermore, inhibition by methionine required a minimum level (7%) of serum in the growth medium and inhibition was not sensitive to cycloheximide. Only amino acids that are transported by system A (including the nonmetabolized analogue methylaminoisobutyric acid) specifically inhibited glycolysis in tumor cells. The only exception was phenylalanine, which was toxic to both transformed and normal cell lines.

  8. Genetic changes in Mammalian cells transformed by helium cells

    Energy Technology Data Exchange (ETDEWEB)

    Durante, M.; Grossi, G. (Naples Univ. (Italy). Dipt. di Scienze Fisiche); Yang, T.C.; Roots, R. (Lawrence Berkeley Lab., CA (USA))

    1990-11-01

    Midterm Syrian Hamster embryo (SHE) cells were employed to study high LET-radiation induced tumorigenesis. Normal SHE cells (secondary passage) were irradiated with accelerated helium ions at an incident energy of 22 MeV/u (9--10 keV/{mu}m). Transformed clones were isolated after growth in soft agar of cells obtained from the foci of the initial monolayer plated postirradiation. To study the progression process of malignant transformation, the transformed clones were followed by monolayer subculturing for prolonged periods of time. Subsequently, neoplasia tests in nude mice were done. In this work, however, we have focused on karyotypic changes in the banding patterns of the chromosomes during the early part of the progressive process of cell transformation for helium ion-induced transformed cells. 26 refs., 5 figs., 2 tabs.

  9. Cell transformation as aberrant differentiation:Environmentally dependent spontaneous transformation of NIH 3T3 cells

    Institute of Scientific and Technical Information of China (English)

    XUKANG; HARRYRUBIN

    1990-01-01

    NIH 3T3 cells,a mouse fibroblast cell line used as routine target cells for transfection experiments,undergo spontaneous transformation in our experiments after they form a confluent sheet in medium containing fetal bovine serum (FBS) of lower concentration of calf serum (CS).The transformation takes the form of foci of multiplying cells among the surrounding cells which have stopped cell division.However,no focus of trans formed cells could be seen in medium containing high concentration (10%) of CS.Further experiments indicated that the frequency of transformation is highly dependent on the concentration of serum and the transformation in CS is changeable when the cells are passaged in FBS.&3H-thymidine autoradiography has been proved to be a sensitive measurement indicator for focus formation.Our results suggest that the high frequency of transformation and its dependence on confluency as well as on medium composition are characteristics of cell differentiation rather than mutation.The role of the NIH 3T3 cell line as a cancer-initiated cell population and its accelerated transformation by ras oncogene might be considered as a form of tumor promotion is discussed.

  10. Chemical modification of neoplastic cell transformation by heavy ion radiation

    International Nuclear Information System (INIS)

    Quantitative data on chemical modification of neoplastic cell transformation by heavy-ion radiation was obtained using in-vitro cell transformation technique. The specific aims were 1) to test the potential effects of various chemicals on the expression of cell transformation, and 2) to systematically collect information on the mechanisms of expression and progression of cell transformation by ionizing radiation. Recent experimental studies with DMSO, 5-azacytidine, and dexamethasone suggest that DMSO can effectively suppress the neoplastic cell transformation by high-LET radiation and that some nonmutagenic changes in DNA may be important in modifying the expression, and progression of radiation-induced cell transformation

  11. Mechanisms of radiation-induced neoplastic cell transformation

    Energy Technology Data Exchange (ETDEWEB)

    Yang, T.C.H.; Tobias, C.A.

    1984-04-01

    Studies with cultured mammalian cells demonstrated clearly that radiation can transform cells directly and can enhance the cell transformation by oncogenic DNA viruses. In general, high-LET heavy-ion radiation can be more effective than X and gamma rays in inducing neoplastic cell transformation. Various experimental results indicate that radiation-induced DNA damage, most likely double-strand breaks, is important for both the initiation of cell transformation and for the enhancement of viral transformation. Some of the transformation and enhancement lesions can be repaired properly in the cell, and the amount of irrepairable lesions produced by a given dose depends on the quality of radiation. An inhibition of repair processes with chemical agents can increase the transformation frequency of cells exposed to radiation and/or oncogenic viruses, suggesting that repair mechanisms may play an important role in the radiation transformation. The progression of radiation-transformed cells appears to be a long and complicated process that can be modulated by some nonmutagenic chemical agents, e.g., DMSO. Normal cells can inhibit the expression of transforming properties of tumorigenic cells through an as yet unknown mechanism. The progression and expression of transformation may involve some epigenetic changes in the irradiated cells. 38 references, 15 figures, 1 table.

  12. TRANSFORMATION

    Energy Technology Data Exchange (ETDEWEB)

    LACKS,S.A.

    2003-10-09

    Transformation, which alters the genetic makeup of an individual, is a concept that intrigues the human imagination. In Streptococcus pneumoniae such transformation was first demonstrated. Perhaps our fascination with genetics derived from our ancestors observing their own progeny, with its retention and assortment of parental traits, but such interest must have been accelerated after the dawn of agriculture. It was in pea plants that Gregor Mendel in the late 1800s examined inherited traits and found them to be determined by physical elements, or genes, passed from parents to progeny. In our day, the material basis of these genetic determinants was revealed to be DNA by the lowly bacteria, in particular, the pneumococcus. For this species, transformation by free DNA is a sexual process that enables cells to sport new combinations of genes and traits. Genetic transformation of the type found in S. pneumoniae occurs naturally in many species of bacteria (70), but, initially only a few other transformable species were found, namely, Haemophilus influenzae, Neisseria meningitides, Neisseria gonorrheae, and Bacillus subtilis (96). Natural transformation, which requires a set of genes evolved for the purpose, contrasts with artificial transformation, which is accomplished by shocking cells either electrically, as in electroporation, or by ionic and temperature shifts. Although such artificial treatments can introduce very small amounts of DNA into virtually any type of cell, the amounts introduced by natural transformation are a million-fold greater, and S. pneumoniae can take up as much as 10% of its cellular DNA content (40).

  13. Cell Transformation by RNA Viruses: An Overview

    Directory of Open Access Journals (Sweden)

    Hung Fan

    2011-06-01

    Full Text Available Studies of oncogenic viruses have made seminal contributions to the molecular biology of cancer. Key discoveries include the identification of viral oncogenes and cellular proto-oncogenes, elucidation of signal transduction pathways, and identification of tumor suppressor genes. The origins of cancer virology began almost exactly one hundred years ago with the discovery of avian sarcoma and acute leukemia viruses—RNA-containing viruses of the retrovirus family. The study of animal cancer viruses accelerated beginning in the late 1960s and early 1970s, with the discovery of DNA viruses that could transform cells in culture, and the development of quantitative assays for transformation by DNA and RNA-containing tumor viruses. The discovery of reverse transcriptase in retroviruses in 1970 also greatly accelerated research on these viruses. Indeed RNA and DNA tumor viruses led the way in cancer molecular biology during this era before molecular cloning. It was possible to physically purify virus particles and generate specific hybridization probes for viral DNA and RNA at a time when it was not possible to analyze cellular genes in the same manner. [...

  14. Radiogenic transformation of human mammary epithelial cells in vitro

    Science.gov (United States)

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

    1996-01-01

    Cancer induction by space radiations is a major concern for manned space exploration. Accurate assessment of radiation risk at low doses requires basic understanding of mechanism(s) of radiation carcinogenesis. For determining the oncogenic effects of ionizing radiation in human epithelial cells, we transformed a mammary epithelial cell line (185B5), which was immortalized by benzo(a)pyrene, with energetic heavy ions and obtained several transformed clones. These transformed cells showed growth properties on Matrigel similar to human mammary tumor cells. To better understand the mechanisms of radiogenic transformation of human cells, we systematically examined the alterations in chromosomes and cancer genes. Among 16 autosomes examined for translocations, by using fluorescence in situ hybridization (FISH) technique, chromosomes 3, 12, 13, 15, 16, and 18 appeared to be normal in transformed cells. Chromosomes 1, 4, 6, 8, and 17 in transformed cells, however, showed patterns different from those in nontransformed cells. Southern blot analyses indicated no detectable alterations in myc, ras, Rb, or p53 genes. Further studies of chromosome 17 by using in situ hybridization with unique sequence p53 gene probe and a centromere probe showed no loss of p53 gene in transformed cells. Experimental results from cell fusion studies indicated that the transforming gene(s) is recessive. The role of genomic instability and tumor suppressor gene(s) in radiogenic transformation of human breast cells remains to be identified.

  15. In Vitro transformation of LW13 Rat liver epithelial Cells

    Institute of Scientific and Technical Information of China (English)

    SHICAN; KARLFETNANSKY; 等

    1992-01-01

    A rat liver epithelial cell line designated LW 13 was established using a sequential sedimentation method.The cell line retained many normal proerties of liver epithelial cells and showed some structural and functional features resembling those of liver parenchymal cells,LW13 cells became malignant after the intrduction of exogenous transforming EJ Ha ras gene,Tumors produced by inoculation of the transformed cells into baby rats contained areas of poorly differentialted hepatocellular carcinoma,In situ hybridization analysis confirmed the random rather than specific integration of exogenous ras gene into host chromosomes.Furthermore,an at least tenfold increase in the expression of the endogenous c mys gene was detected among transformed cell lines,suggesting the involvement of the c myc proto oncogene in the in vitro transformation of rat liver epithelial cells by EJ Ha ras oncogene.

  16. Species-specific transformation of T cells by HVMNE

    International Nuclear Information System (INIS)

    HVMNE is an Epstein-Barr virus (EBV)-like lymphocryptovirus (LCV) originally isolated from a Macaca nemestrina with CD8+ T cell mycosis fungoides/cutaneous T cell lymphoma (Blood 98 (2001), 2193). HVMNE transforms rabbit T cells in vitro and causes T cell lymphoma in New Zealand white rabbits. Here we demonstrate that HVMNE also immortalizes T cells from mustached tamarins but not those from owl monkeys, common marmosets, squirrel monkeys, black-capped capuchins, and humans. Cytogenetic and FACS analysis revealed the true origin and T cell lineage of the transformed tamarin T cell lines. Tamarin T cells contained HVMNE DNA sequence and displayed a decreased requirement for the IL-2 cytokine for growth. Thus, this EBV-like virus from M. nemestrina differs from the other EBV-like viruses found in nonhuman primates inasmuch as it appears to preferentially transform T cells

  17. Intracellular levels of calmodulin are increased in transformed cells

    Institute of Scientific and Technical Information of China (English)

    WANG; HONGQINGZHANG; 等

    1992-01-01

    By using Hoechst 33342,rabbit anti calmodulin antibody,FITC-labeled goat anti rabbit IgG and SR101(sulfo rhodamine 101)simultaneously to stain individual normal and transformed cells,the microspectrophotometric analysis demonstrated that 3 markers which represented the nucleus,calmodulin and total protein respectively,could be recognized in individualj cells without interference,The phase of the cell cycle was determined by DNA content(Hoechst 33342),We found that in transformed cells(NIH3T3) tsRSV-LA90,cultured at 33℃ and transformed C3H10T1/2 Cells),the ration of calmodulin to total protein (based on the phases of cell cycle)was higher than that in normal cells (NIH3T3 tsRSV-LA90 cells,cultured at 39℃ and C3H10T1/2 cells)in every cell cycle phase,This ration increased obviously only from G1 to S phase in either normal or transformed cells.The results showed that calmodulinreally increased during the transformation,and its increase was specific.In the meantime when cells proceeded from G1 to S.the intraceollular calmodulin content also increased specifically.

  18. Battery Cell Voltage Sensing and Balancing Using Addressable Transformers

    Science.gov (United States)

    Davies, Francis

    2009-01-01

    A document discusses the use of saturating transformers in a matrix arrangement to address individual cells in a high voltage battery. This arrangement is able to monitor and charge individual cells while limiting the complexity of circuitry in the battery. The arrangement has inherent galvanic isolation, low cell leakage currents, and allows a single bad cell in a battery of several hundred cells to be easily spotted.

  19. A color discriminating broad range cell staining technology for early detection of cell transformation

    Directory of Open Access Journals (Sweden)

    Sagiv Idit

    2009-01-01

    Full Text Available Background: Advanced diagnostic tools stand today at the heart of successful cancer treatment. CellDetect® is a new histochemical staining technology that enables color discrimination between normal cells and a wide variety of neoplastic tissues. Using this technology, normal cells are colored blue/green, while neoplastic cells color red. This tinctorial difference coincides with clear morphological visualization properties, mainly in tissue samples. Here we show that the CellDetect® technology can be deployed to distinguish normal cells from transformed cells and most significantly detect cells in their early pre-cancerous transformed state. Materials and Methods: In tissue culture, we studied the ability of the CellDetect® technology to color discriminate foci in a number of two stage transformation systems as well as in a well defined cellular model for cervical cancer development, using HPV16 transformed keratinocytes. Results: In all these cellular systems, the CellDetect® technology was able to sensitively show that all transformed cells, including pre-cancerous HPV 16 transformed cells, are colored red, whereas normal cells are colored blue/green. The staining technology was able to pick up: (i early transformation events in the form of small type 1 foci (non-invasive, not piled up small, with parallel alignment of cells, and (ii early HPV16 transformed cells, even prior to their ability to form colonies in soft agar. The study shows the utility of the CellDetect® technology in early detection of transformation events.

  20. Cell Phones Transform a Science Methods Course

    Science.gov (United States)

    Madden, Lauren

    2012-01-01

    A science methods instructor intentionally encouraged cell phone use for class work to discover how cell phones can be used as research tools to enhance the content and engage the students. The anecdotal evidence suggested that students who used their smartphones as research tools experienced the science content and pedagogical information…

  1. Cell-mediated mutagenesis and cell transformation of mammalian cells by chemical carcinogens

    International Nuclear Information System (INIS)

    We have developed a cell-mediated mutagenesis assay in which cells with the appropriate markers for mutagenesis are co-cultivated with either lethally irradiated rodent embryonic cells that can metabolize carcinogenic hydrocarbons or with primary rat liver cells that can metabolize chemicals carcinogenic to the liver. During co-cultivation, the reactive metabolites of the procarcinogen appear to be transmitted to the mutable cells and induce mutations in them. Assays of this type make it possible to demonstrate a relationship between carcinogenic potency of the chemicals and their ability to induce mutations in mammalian cells. In addition, by simultaneously comparing the frequencies of transformation and mutation induced in normal diploid hamster cells by benzo(a)pyrene (BP) and one of its metabolites, it is possible to estimate the genetic target size for cell transformation in vitro

  2. CD30+ large cell transformation of mycosis fungoides during pregnancy

    Directory of Open Access Journals (Sweden)

    Farahnaz Fatemi Naeini

    2013-01-01

    Full Text Available Mycosis fungoides (MF a cutaneous T-cell lymphoma, is a subgroup of non-Hodgkin′s lymphomas, characterized by skin infiltration and occasionally systemic involvement. MF coincidence with pregnancy is rare. The effect of pregnancy on MF and the effect of this disease on pregnancy are still unknown. There are few case reports about pregnancy and its deleterious effect on the clinical course of MF. This case report is about a 30-years-old female with MF who became pregnant and after delivery developed CD30+ large cell transformation; this is the first report of large cell transformation of MF related to pregnancy.

  3. Implementation of additional cell types for transformation studies

    International Nuclear Information System (INIS)

    Our experience with 10T1/2 cells, the cell line generally used for such experiments, indicates that these cells are not suitable for our studies. We have recently made arrangements to obtain two additional cell lines recently developed by G.W. Barendsen. One of these, the NBCH-3 cell line, was derived from a clone which developed spontaneously in a primary cell culture of tissues from a newborn Chinese hamster. The assay procedure to be used with this cell line is the same as that for the C3H 10T1/2 cells; however, clonal development and morphology are considerably clearer. In addition, another cell line, denoted WAGR-2, was also derived in Barendsen's laboratory from the tissues of a newborn Wistar rat. The origin of the cells is again uncertain, but the procedures used for determining transformation frequencies with this cell line are essentially the same as for C3H 10T1/2 cells. Use of one or both of these new cell systems for our transformation experiments should not only increase the capabilities of the studies, but their use should make the assay both more accurate and simpler to perform

  4. Fuel Transformer Solid Oxide Fuel Cell

    Energy Technology Data Exchange (ETDEWEB)

    Norman Bessette; Douglas S. Schmidt; Jolyon Rawson; Lars Allfather; Anthony Litka

    2005-08-01

    The following report documents the technical approach and conclusions made by Acumentrics Corporation during latest budget period toward the development of a low cost 10kW tubular SOFC power system. The present program, guided under direction from the National Energy Technology Laboratory of the US DOE, is a nine-year cost shared Cooperative Agreement totaling close to $74M funded both by the US DOE as well as Acumentrics Corporation and its partners. The latest budget period ran from January of 2005 through June 2005. Work focused on cell technology enhancements as well as BOP and power electronics improvements and overall system design. Significant progress was made in increasing cell power enhancements as well as decreasing material cost in a drive to meet the SECA cost targets. The following report documents these accomplishments in detail as well as the layout plans for further progress in next budget period.

  5. FUEL TRANSFORMER SOLID OXIDE FUEL CELL

    Energy Technology Data Exchange (ETDEWEB)

    Norman Bessette; Douglas S. Schmidt; Jolyon Rawson; Lars Allfather; Anthony Litka

    2005-03-24

    The following report documents the technical approach and conclusions made by Acumentrics Corporation during latest budget period toward the development of a low cost 10kW tubular SOFC power system. The present program, guided under direction from the National Energy Technology Laboratory of the US DOE, is a nine-year cost shared Cooperative Agreement totaling close to $74M funded both by the US DOE as well as Acumentrics Corporation and its partners. The latest budget period ran from July of 2004 through January 2004. Work was focused on cell technology enhancements as well as BOP and power electronics improvements and overall system design. Significant progress was made in increasing cell power enhancements as well as decreasing material cost in a drive to meet the SECA cost targets. The following report documents these accomplishments in detail as well as the lay out plans for further progress in next budget period.

  6. Fuel Transformer Solid Oxide Fuel Cell

    Energy Technology Data Exchange (ETDEWEB)

    Norman Bessette; Douglas S. Schmidt; Jolyon Rawson; Rhys Foster; Anthony Litka

    2006-07-27

    The following report documents the technical approach and conclusions made by Acumentrics Corporation during latest budget period toward the development of a low cost 10kW tubular SOFC power system. The present program, guided under direction from the National Energy Technology Laboratory of the US DOE, is a nine-year cost shared Cooperative Agreement totaling close to $74M funded both by the US DOE as well as Acumentrics Corporation and its partners. The latest budget period ran from January of 2006 through June 2006. Work focused on cell technology enhancements as well as BOP and power electronics improvements and overall system design. Significant progress was made in increasing cell power enhancements as well as decreasing material cost in a drive to meet the SECA cost targets. The following report documents these accomplishments in detail as well as the layout plans for further progress in next budget period.

  7. Altered cytoskeletal structures in transformed cells exhibiting obviously metastatic capabilities

    Institute of Scientific and Technical Information of China (English)

    LINZHONGXIANG; WUBINGQUAN; 等

    1990-01-01

    Cytoskeletal changes in transformed cells (LM-51) eshibiting obviously metastatic capabilities were investigated by utilization of double-fluorescent labelling through combinations of:(1) tubulin indirect immunofluorescence plus Rhodamine-phalloidin staining of F-actins;(2) indirect immunofluorescent staining with α-actinin polyclonal-and vinculin monoclonal antibodies.The LM-51 cells which showed metastatic index of >50% were derived from lung metastasis in nude mice after subcutaneous inoculation of human highly metastatic tumor DNA transfected NIH3T3 cell transformants.The parent NIH3T3 cells exhibited well-organized microtubules,prominent stress fibers and adhesion plaques while their transformants showed remarkable cytoskeletal alterations:(1)reduced microtubules but increased MTOC fluorescence;(2)disrupted stress fibers and fewer adhesion plaques with their protein components redistributed in the cytoplasm;(3)Factin-and α-actinin/vinculin aggregates appeared in the cytoplasm.These aggregates were dot-like,varied in size(0.1-0.4μm) and number,located near the ventral surface of the cells.TPA-induced actin/vinculin bodies were studied too.Indications that actin and α-actinin/vinculin redistribution might be important alterations involved in the expression of metastatic capabilities of LM-51 transformed cells were discussed.

  8. Characterization of a transformed rat retinal ganglion cell line.

    Science.gov (United States)

    Krishnamoorthy, R R; Agarwal, P; Prasanna, G; Vopat, K; Lambert, W; Sheedlo, H J; Pang, I H; Shade, D; Wordinger, R J; Yorio, T; Clark, A F; Agarwal, N

    2001-01-31

    The purpose of the present study was to establish a rat retinal ganglion cell line by transformation of rat retinal cells. For this investigation, retinal cells were isolated from postnatal day 1 (PN1) rats and transformed with the psi2 E1A virus. In order to isolate retinal ganglion cells (RGC), single cell clones were chosen at random from the transformed cells. Expression of Thy-1 (a marker for RGC), glial fibrillary acidic protein (GFAP, a positive marker for Muller cells), HPC-1/syntaxin (a marker for amacrine cells), 8A1 (a marker for horizontal and ganglion cells) and neurotrophins was studied using reverse transcriptase-polymerase chain reaction (RT-PCR), immunoblotting and immunocytochemistry. One of the retinal cell clones, designated RGC-5, was positive for Thy-1, Brn-3C, Neuritin, NMDA receptor, GABA-B receptor, and synaptophysin expression and negative for GFAP, HPC-1, and 8A1, suggesting that it represented a putative RGC clone. The results of RT-PCR analysis were confirmed by immunocytochemistry for Thy-1 and GFAP. Upon further characterization by immunoblotting, the RGC-5 clone was positive for Thy-1, negative for GFAP, 8A1 and syntaxin. RGC 5 cells were also positive for the expression of neurotrophins and their cognate receptors. To establish the physiological relevance of RGC-5, the effects of serum/trophic factor deprivation and glutamate toxicity were analyzed to determine if these cells would undergo apoptosis. The protective effects of neurotrophins on RGC-5 after serum deprivation was also investigated. Apoptosis was studied by terminal deoxynucleotidyl transferase-mediated fluoresceinated dUTP nick end labeling (TUNEL). Serum deprivation resulted in apoptosis and supplementation with both BDNF and NT-4 in the growth media, protected the RGC-5 cells from undergoing apoptosis. On differentiation with succinyl concanavalin A (sConA), RGC-5 cells became sensitive to glutamate toxicity, which could be reversed by inclusion of ciplizone (MK801

  9. The Quest for Targets Executing MYC-Dependent Cell Transformation

    Science.gov (United States)

    Hartl, Markus

    2016-01-01

    MYC represents a transcription factor with oncogenic potential converting multiple cellular signals into a broad transcriptional response, thereby controlling the expression of numerous protein-coding and non-coding RNAs important for cell proliferation, metabolism, differentiation, and apoptosis. Constitutive activation of MYC leads to neoplastic cell transformation, and deregulated MYC alleles are frequently observed in many human cancer cell types. Multiple approaches have been performed to isolate genes differentially expressed in cells containing aberrantly activated MYC proteins leading to the identification of thousands of putative targets. Functional analyses of genes differentially expressed in MYC-transformed cells had revealed that so far more than 40 upregulated or downregulated MYC targets are actively involved in cell transformation or tumorigenesis. However, further systematic and selective approaches are required for determination of the known or yet unidentified targets responsible for processing the oncogenic MYC program. The search for critical targets in MYC-dependent tumor cells is exacerbated by the fact that during tumor development, cancer cells progressively evolve in a multistep process, thereby acquiring their characteristic features in an additive manner. Functional expression cloning, combinatorial gene expression, and appropriate in vivo tests could represent adequate tools for dissecting the complex scenario of MYC-specified cell transformation. In this context, the central goal is to identify a minimal set of targets that suffices to phenocopy oncogenic MYC. Recently developed genomic editing tools could be employed to confirm the requirement of crucial transformation-associated targets. Knowledge about essential MYC-regulated genes is beneficial to expedite the development of specific inhibitors to interfere with growth and viability of human tumor cells in which MYC is aberrantly activated. Approaches based on the principle of

  10. The quest for targets executing MYC-dependent cell transformation

    Directory of Open Access Journals (Sweden)

    Markus eHartl

    2016-06-01

    Full Text Available MYC represents a transcription factor with oncogenic potential converting multiple cellular signals into a broad transcriptional response, thereby controlling the expression of numerous protein-coding and non-coding RNAs important for cell proliferation, metabolism, differentiation, and apoptosis. Constitutive activation of MYC leads to neoplastic cell transformation, and deregulated MYC alleles are frequently observed in many human cancer cell types. Multiple approaches have been performed to isolate genes differentially expressed in cells containing aberrantly activated MYC proteins leading to the identification of thousands of putative targets. Functional analyses of genes differentially expressed in MYC-transformed cells had revealed that so far more than forty upregulated or downregulated MYC targets are actively involved in cell transformation or tumorigenesis. However, for determination which of the known, or yet unidentified targets are responsible for processing the oncogenic MYC program, further systematic and selective approaches are required. The search for critical targets in MYC-dependent tumor cells is exacerbated by the fact that during tumor development, cancer cells progressively evolve in a multistep process thereby acquiring their characteristic features in an additive manner. Functional expression cloning, combinatorial gene expression and appropriate in vivo tests could represent adequate tools for dissecting the complex scenario of MYC-specified cell transformation. In this context, the central goal is to identify a minimal set of targets that suffices to phenocopy oncogenic MYC. Recently developed genomic editing tools could be employed to confirm the requirement of crucial transformation-associated targets.Knowledge about essential MYC regulated genes is beneficial to expedite the development of specific inhibitors to interfere with growth and viability of human tumor cells in which MYC is aberrantly activated

  11. Inhibition of Geranylgeranyl Transferase-I Decreases Cell Viability of HTLV-1-Transformed Cells

    Directory of Open Access Journals (Sweden)

    Cynthia A. Pise-Masison

    2011-10-01

    Full Text Available Human T-cell leukemia virus type-1 (HTLV-1 is the etiological agent of adult T-cell leukemia (ATL, an aggressive and highly chemoresistant malignancy. Rho family GTPases regulate multiple signaling pathways in tumorigenesis: cytoskeletal organization, transcription, cell cycle progression, and cell proliferation. Geranylgeranylation of Rho family GTPases is essential for cell membrane localization and activation of these proteins. It is currently unknown whether HTLV-1-transformed cells are preferentially sensitive to geranylgeranylation inhibitors, such as GGTI-298. In this report, we demonstrate that GGTI-298 decreased cell viability and induced G2/M phase accumulation of HTLV-1-transformed cells, independent of p53 reactivation. HTLV-1-LTR transcriptional activity was inhibited and Tax protein levels decreased following treatment with GGTI-298. Furthermore, GGTI-298 decreased activation of NF-κB, a downstream target of Rho family GTPases. These studies suggest that protein geranylgeranylation contributes to dysregulation of cell survival pathways in HTLV-1-transformed cells.

  12. UV stimulation of DNA-mediated transformation of human cells

    International Nuclear Information System (INIS)

    Irradiation of dominant marker DNA with UV light (150 to 1,000 J/m2) was found to stimulate the transformation of human cells by this marker from two- to more than fourfold. This phenomenon is also displayed by xeroderma pigmentosum cells, which are deficient in the excision repair of UV-induced pyrimidine dimers in the DNA. Also, exposure to UV of the transfected (xeroderma pigmentosum) cells enhanced the transfection efficiency. Removal of the pyrimidine dimers from the DNA by photoreactivating enzyme before transfection completely abolished the stimulatory effect, indicating that dimer lesions are mainly responsible for the observed enhancement. A similar stimulation of the transformation efficiency is exerted by 2-acetoxy-2-acetylaminofluorene modification of the DNA. These findings suggest that lesions which are targets for the excision repair pathway induce the increase in transformation frequency. The stimulation was found to be independent of sequence homology between the irradiated DNA and the host chromosomal DNA. Therefore, the increase of the transformation frequency is not caused by a mechanism inducing homologous recombination between these two DNAs. UV treatment of DNA before transfection did not have a significant effect on the amount of DNA integrated into the xeroderma pigmentosum genome

  13. Plant Cell Division Analyzed by Transient Agrobacterium-Mediated Transformation of Tobacco BY-2 Cells.

    Science.gov (United States)

    Buschmann, Henrik

    2016-01-01

    The continuing analysis of plant cell division will require additional protein localization studies. This is greatly aided by GFP-technology, but plant transformation and the maintenance of transgenic lines can present a significant technical bottleneck. In this chapter I describe a method for the Agrobacterium-mediated genetic transformation of tobacco BY-2 cells. The method allows for the microscopic analysis of fluorescence-tagged proteins in dividing cells in within 2 days after starting a coculture. This transient transformation procedure requires only standard laboratory equipment. It is hoped that this rapid method would aid researchers conducting live-cell localization studies in plant mitosis and cytokinesis.

  14. Red Blood Cells Estimation Using Hough Transform Technique

    Directory of Open Access Journals (Sweden)

    Nasrul Humaimi Mahmood

    2012-05-01

    Full Text Available The number of red blood cells contributes more to clinical diagnosis with respect to blood diseases. Theaim of this research is to produce a computer vision system that can detect and estimate the number of redblood cells in the blood sample image. Morphological is a very powerful tool in image processing, and it isbeen used to segment and extract the red blood cells from the background and other cells. The algorithmused features such as shape of red blood cells for counting process, and Hough transform is introduced inthis process. The result presented here is based on images with normal blood cells. The tested data consistsof 10 samples and produced the accurate estimation rate closest to 96% from manual counting.

  15. Evaluation of tellurium toxicity in transformed and non-transformed human colon cells.

    Science.gov (United States)

    Vij, Puneet; Hardej, Diane

    2012-11-01

    Diphenyl ditelluride (DPDT) and tellurium tetrachloride (TeCl(4)) were evaluated for toxicity in transformed (HT-29, Caco-2) and non-transformed colon cells (CCD-18Co). Significant decreases in viability were observed with DPDT exposure in HT-29 (62.5-1000 μM), Caco-2 (31.25-1000 μM) and CCD-18Co cells (500-1000 μM) and with TeCl(4) in HT-29 (31.25-1000 μM), Caco-2 (31.25-1000 μM) and CCD-18Co cells (500-1000 μM). Light microscopy confirmed viability analysis. Significant increases in caspase 3/7 and 9 activity were observed with DPDT in HT-29 (500-1000 μM) and CCD-18Co cells (1000 μM) indicating apoptosis. No significant increases in caspases were seen with TeCl(4) indicating necrosis. Apoptosis or necrosis was confirmed with fluorescent staining (FITC-Annexin, Hoechst 33342 and Ethidium Homodimer). Significant decreases in GSH/GSSG ratio were observed with DPDT in HT-29 (62.5-1000 μM), and CCD-18Co cells (1000 μM) and with TeCl(4) in HT-29 (62.5-1000 μM) and CCD-18Co cells (250-1000 μM). We concluded that cells treated with DPDT resulted in apoptosis and TeCl(4) treatment in necrosis. GSH/GSSG ratio shifts indicate oxidative mechanisms are involved. PMID:23068156

  16. Whole-cell fungal transformation of precursors into dyes

    Directory of Open Access Journals (Sweden)

    Jarosz-Wilkołazka Anna

    2010-07-01

    Full Text Available Abstract Background Chemical methods of producing dyes involve extreme temperatures and unsafe toxic compounds. Application of oxidizing enzymes obtained from fungal species, for example laccase, is an alternative to chemical synthesis of dyes. Laccase can be replaced by fungal biomass acting as a whole-cell biocatalyst with properties comparable to the isolated form of the enzyme. The application of the whole-cell system simplifies the transformation process and reduces the time required for its completion. In the present work, four fungal strains with a well-known ability to produce laccase were tested for oxidation of 17 phenolic and non-phenolic precursors into stable and non-toxic dyes. Results An agar-plate screening test of the organic precursors was carried out using four fungal strains: Trametes versicolor, Fomes fomentarius, Abortiporus biennis, and Cerrena unicolor. Out of 17 precursors, nine were transformed into coloured substances in the presence of actively growing fungal mycelium. The immobilized fungal biomass catalyzed the transformation of 1 mM benzene and naphthalene derivatives in liquid cultures yielding stable and non-toxic products with good dyeing properties. The type of fungal strain had a large influence on the absorbance of the coloured products obtained after 48-hour transformation of the selected precursors, and the most effective was Fomes fomentarius (FF25. Whole-cell transformation of AHBS (3-amino-4-hydroxybenzenesulfonic acid into a phenoxazinone dye was carried out in four different systems: in aqueous media comprising low amounts of carbon and nitrogen source, in buffer, and in distilled water. Conclusions This study demonstrated the ability of four fungal strains belonging to the ecological type of white rot fungi to transform precursors into dyes. This paper highlights the potential of fungal biomass for replacing isolated enzymes as a cheaper industrial-grade biocatalyst for the synthesis of dyes and other

  17. Metric dynamics for membrane transformation through regulated cell proliferation

    OpenAIRE

    Ito, Hiroshi C.

    2016-01-01

    This study develops an equation for describing three-dimensional membrane transformation through proliferation of its component cells regulated by morphogen density distributions on the membrane. The equation is developed in a two-dimensional coordinate system mapped on the membrane, referred to as the membrane coordinates. When the membrane expands, the membrane coordinates expand in the same manner so that the membrane is invariant in the coordinates. In the membrane coordinate system, the ...

  18. Cell-to-cell transformation in Escherichia coli: a novel type of natural transformation involving cell-derived DNA and a putative promoting pheromone.

    Directory of Open Access Journals (Sweden)

    Rika Etchuuya

    Full Text Available Escherichia coli is not assumed to be naturally transformable. However, several recent reports have shown that E. coli can express modest genetic competence in certain conditions that may arise in its environment. We have shown previously that spontaneous lateral transfer of non-conjugative plasmids occurs in a colony biofilm of mixed E. coli strains (a set of a donor strain harbouring a plasmid and a plasmid-free recipient strain. In this study, with high-frequency combinations of strains and a plasmid, we constructed the same lateral plasmid transfer system in liquid culture. Using this system, we demonstrated that this lateral plasmid transfer was DNase-sensitive, indicating that it is a kind of transformation in which DNase-accessible extracellular naked DNA is essential. However, this transformation did not occur with purified plasmid DNA and required a direct supply of plasmid from co-existing donor cells. Based on this feature, we have termed this transformation type as 'cell-to-cell transformation'. Analyses using medium conditioned with the high-frequency strain revealed that this strain released a certain factor(s that promoted cell-to-cell transformation and arrested growth of the other strains. This factor is heat-labile and protease-sensitive, and its roughly estimated molecular mass was between ∼9 kDa and ∼30 kDa, indicating that it is a polypeptide factor. Interestingly, this factor was effective even when the conditioned medium was diluted 10(-5-10(-6, suggesting that it acts like a pheromone with high bioactivity. Based on these results, we propose that cell-to-cell transformation is a novel natural transformation mechanism in E. coli that requires cell-derived DNA and is promoted by a peptide pheromone. This is the first evidence that suggests the existence of a peptide pheromone-regulated transformation mechanism in E. coli and in Gram-negative bacteria.

  19. Image classifiers for the cell transformation assay: a progress report

    Science.gov (United States)

    Urani, Chiara; Crosta, Giovanni F.; Procaccianti, Claudio; Melchioretto, Pasquale; Stefanini, Federico M.

    2010-02-01

    The Cell Transformation Assay (CTA) is one of the promising in vitro methods used to predict human carcinogenicity. The neoplastic phenotype is monitored in suitable cells by the formation of foci and observed by light microscopy after staining. Foci exhibit three types of morphological alterations: Type I, characterized by partially transformed cells, and Types II and III considered to have undergone neoplastic transformation. Foci recognition and scoring have always been carried visually by a trained human expert. In order to automatically classify foci images one needs to implement some image understanding algorithm. Herewith, two such algorithms are described and compared by performance. The supervised classifier (as described in previous articles) relies on principal components analysis embedded in a training feedback loop to process the morphological descriptors extracted by "spectrum enhancement" (SE). The unsupervised classifier architecture is based on the "partitioning around medoids" and is applied to image descriptors taken from histogram moments (HM). Preliminary results suggest the inadequacy of the HMs as image descriptors as compared to those from SE. A justification derived from elementary arguments of real analysis is provided in the Appendix.

  20. Insect cell transformation vectors that support high level expression and promoter assessment in insect cell culture

    Science.gov (United States)

    A somatic transformation vector, pDP9, was constructed that provides a simplified means of producing permanently transformed cultured insect cells that support high levels of protein expression of foreign genes. The pDP9 plasmid vector incorporates DNA sequences from the Junonia coenia densovirus th...

  1. Transformation

    DEFF Research Database (Denmark)

    Peters, Terri

    2011-01-01

    Artiklen diskuterer ordet "transformation" med udgangspunkt i dels hvorledes ordet bruges i arkitektfaglig terminologi og dels med fokus på ordets potentielle indhold og egnethed i samme teminologi.......Artiklen diskuterer ordet "transformation" med udgangspunkt i dels hvorledes ordet bruges i arkitektfaglig terminologi og dels med fokus på ordets potentielle indhold og egnethed i samme teminologi....

  2. Multiple host-cell recombination pathways act in Agrobacterium-mediated transformation of plant cells.

    Science.gov (United States)

    Mestiri, Imen; Norre, Frédéric; Gallego, Maria E; White, Charles I

    2014-02-01

    Using floral-dip, tumorigenesis and root callus transformation assays of both germline and somatic cells, we present here results implicating the four major non-homologous and homologous recombination pathways in Agrobacterium-mediated transformation of Arabidopsis thaliana. All four single mutant lines showed similar mild reductions in transformability, but knocking out three of four pathways severely compromised Agrobacterium-mediated transformation. Although integration of T-DNA into the plant genome is severely compromised in the absence of known DNA double-strand break repair pathways, it does still occur, suggesting the existence of other pathways involved in T-DNA integration. Our results highlight the functional redundancy of the four major plant recombination pathways in transformation, and provide an explanation for the lack of strong effects observed in previous studies on the roles of plant recombination functions in transformation.

  3. Scientific projection paper for mutagenesis, transformation and cell killing

    International Nuclear Information System (INIS)

    Our knowledge about mutagenesis, transformation, and cell killing by ionizing radiation consists of large bodies of data, which are potentially useful in terms of application to human risk assessment and to the constructive use of radiation, as in cancer treatment. The three end-points discussed above are united by at least five significant concepts in radiation research strategy: (1) The inter-relationships among the important end-points, mutation, carcinogenesis, and cell killing. Research on one is meaningful only in the context of information about the other two. (2) The interaction of radiations with other agents in producing these end-points. (3) The mechanisms of action of other environmental mutagenic, carcinogenic, and cytotoxic agents. (4) The use of repair deficient human mutant cells. (5) The study of radiation damage mechanisms. There is no better way to extrapolate laboratory data to the clinical and public worlds than to understand the underlying biological mechanisms that produced the data

  4. TRANSFORMER

    Science.gov (United States)

    Baker, W.R.

    1959-08-25

    Transformers of a type adapted for use with extreme high power vacuum tubes where current requirements may be of the order of 2,000 to 200,000 amperes are described. The transformer casing has the form of a re-entrant section being extended through an opening in one end of the cylinder to form a coaxial terminal arrangement. A toroidal multi-turn primary winding is disposed within the casing in coaxial relationship therein. In a second embodiment, means are provided for forming the casing as a multi-turn secondary. The transformer is characterized by minimized resistance heating, minimized external magnetic flux, and an economical construction.

  5. EDAC: Epithelial defence against cancer-cell competition between normal and transformed epithelial cells in mammals.

    Science.gov (United States)

    Kajita, Mihoko; Fujita, Yasuyuki

    2015-07-01

    During embryonic development or under certain pathological conditions, viable but suboptimal cells are often eliminated from the cellular society through a process termed cell competition. Cell competition was originally identified in Drosophila where cells with different properties compete for survival; 'loser' cells are eliminated from tissues and consequently 'winner' cells become dominant. Recent studies have shown that cell competition also occurs in mammals. While apoptotic cell death is the major fate for losers in Drosophila, outcompeted cells show more variable phenotypes in mammals, such as cell death-independent apical extrusion and cellular senescence. Molecular mechanisms underlying these processes have been recently revealed. Especially, in epithelial tissues, normal cells sense and actively eliminate the neighbouring transformed cells via cytoskeletal proteins by the process named epithelial defence against cancer (EDAC). Here, we introduce this newly emerging research field: cell competition in mammals. PMID:25991731

  6. Culture models of human mammary epithelial cell transformation

    Energy Technology Data Exchange (ETDEWEB)

    Stampfer, Martha R.; Yaswen, Paul

    2000-11-10

    Human pre-malignant breast diseases, particularly ductal carcinoma in situ (DCIS)3 already display several of the aberrant phenotypes found in primary breast cancers, including chromosomal abnormalities, telomerase activity, inactivation of the p53 gene and overexpression of some oncogenes. Efforts to model early breast carcinogenesis in human cell cultures have largely involved studies in vitro transformation of normal finite lifespan human mammary epithelial cells (HMEC) to immortality and malignancy. We present a model of HMEC immortal transformation consistent with the know in vivo data. This model includes a recently described, presumably epigenetic process, termed conversion, which occurs in cells that have overcome stringent replicative senescence and are thus able to maintain proliferation with critically short telomeres. The conversion process involves reactivation of telomerase activity, and acquisition of good uniform growth in the absence and presence of TFGB. We propose th at overcoming the proliferative constraints set by senescence, and undergoing conversion, represent key rate-limiting steps in human breast carcinogenesis, and occur during early stage breast cancer progression.

  7. The input-output transformation of the hippocampal granule cells: from grid cells to place fields

    OpenAIRE

    de Almeida, Licurgo; Idiart, Marco; Lisman, John E.

    2009-01-01

    Grid cells in the rat medial entorhinal cortex fire (periodically) over the entire environment. These cells provide input to hippocampal granule cells whose output is characterized by one or more small place fields. We sought to understand how this input-output transformation occurs. Available information allows simulation of this process with no freely adjustable parameters. We first examined the spatial distribution of excitation in granule cells produced by the convergence of excitatory in...

  8. Liver cell adenoma with malignant transformation: A case report

    Institute of Scientific and Technical Information of China (English)

    Masahiro Ito; Makoto Sasaki; Chun-Yang Wen; Masahiro Nakashima; Toshihito Ueki; Hiromi Ishibashi; Michitami Yano; Masayoshi Kage; Masamichi Kojiro

    2003-01-01

    A 57-year-old woman was referred to our hospital because of a liver mass detected by computed tomography. She had taken oral contraceptives for only one month at the age of thirty. Physical examination revealed no abnormalities, and laboratory data, including hepatic function tests, were within the normal range, with the exception of elevated levels of those serum proteins induced by the absence of vitamin K or by raised levels of the antagonist (PIVKA)-Ⅱ (3 502 AU/ml).Abdominal ultrasonography revealed a hyperechoic mass measuring 10x10 cm in the left posterior segment of the liver. Because hepatocellular carcinoma could not be completely excluded, this mass was resected. The tumor consisted of sheets of uniform cells with clear cytoplasm,perinuclear eosinophilic granules and round nuclei. These histological findings were consistent with liver cell adenoma.Background hepatic tissue appeared normal. After resection of the tumor, serum PIVKA-Ⅱ fell to within the normal range.An area of hepatocellular carcinoma (HCC) with a midtrabecular pattern was immunohistochemically found, which was positive for PIVKA-Ⅱ. Sinusoidal endothelial cells were CD34-positive, containing scattered PIVKA-Ⅱ positive cells.This tumor was therefore finally diagnosed as liver cell adenoma with focal malignant transformation to HCC.

  9. Spontaneous malignant transformation of conventional giant cell tumor

    Energy Technology Data Exchange (ETDEWEB)

    Grote, H.J.; Pomjanski, N.; Boecking, A. [Institute of Cytopathology, Heinrich Heine University, Moorenstrasse 5, 40225, Duesseldorf (Germany); Braun, M. [Orthopedic Hospital Volmarstein, University of Witten/Herdecke, Hartmannstrasse 24, 58300, Wetter (Ruhr) (Germany); Kalinski, T.; Roessner, A. [Department of Pathology, Otto von Guericke University, Leipziger Strasse 44, 39120, Magdeburg (Germany); Back, W.; Bleyl, U. [Department of Pathology, Ruprecht Karls University Heidelberg, University Hospital Mannheim, Theodor-Kutzer-Ufer, 68167, Mannheim (Germany)

    2004-03-01

    Spontaneous malignant transformation of conventional giant cell tumor (GCT) of bone is exceedingly rare. We report on a case of GCT of the iliac crest in a 35-year-old woman with malignant change into a high-grade osteosarcoma 10 years after the first appearance of GCT on a radiograph. Since the patient refused therapy for personal reasons the tumor remained untreated until sarcomatous transformation occurred. Image cytometry showed DNA aneuploidy and a suspiciously high 2c deviation index (2cDI) in the primary bone lesion. A thorough review of the world literature revealed only seven fully documented cases of secondary malignant GCT which matched the definition of a ''sarcomatous growth that occurs at the site of a previously documented benign giant cell tumor'' and not treated by radiotherapy. These cases as well as the current one suggest that a spontaneous secondary malignant GCT presents as a frankly sarcomatous tumor in the form of an osteosarcoma or malignant fibrous histiocytoma. It usually appears at sites of typical GCTs - often without any recurrent intermediate state - and is diagnosed 3 or more years after the primary bone lesion. The prognosis is poor. (orig.)

  10. Spontaneous transformation of adult mesenchymal stem cells from cynomolgus macaques in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Ren, Zhenhua [Cell Therapy Center, Xuanwu Hospital, Capital Medical University, Beijing (China); Key Laboratory of Neurodegeneration, Ministry of Education, Beijing (China); Department of Anatomy, Anhui Medical University, Hefei, 230032 (China); Wang, Jiayin; Zhu, Wanwan; Guan, Yunqian; Zou, Chunlin [Cell Therapy Center, Xuanwu Hospital, Capital Medical University, Beijing (China); Key Laboratory of Neurodegeneration, Ministry of Education, Beijing (China); Chen, Zhiguo, E-mail: chenzhiguo@gmail.com [Cell Therapy Center, Xuanwu Hospital, Capital Medical University, Beijing (China); Key Laboratory of Neurodegeneration, Ministry of Education, Beijing (China); Stanford Institute for Stem Cell Biology and Regenerative Medicine and Department of Neurosurgery, Stanford, CA (United States); Zhang, Y. Alex, E-mail: yaz@bjsap.org [Cell Therapy Center, Xuanwu Hospital, Capital Medical University, Beijing (China); Key Laboratory of Neurodegeneration, Ministry of Education, Beijing (China)

    2011-12-10

    Mesenchymal stem cells (MSCs) have shown potential clinical utility in cell therapy and tissue engineering, due to their ability to proliferate as well as to differentiate into multiple lineages, including osteogenic, adipogenic, and chondrogenic specifications. Therefore, it is crucial to assess the safety of MSCs while extensive expansion ex vivo is a prerequisite to obtain the cell numbers for cell transplantation. Here we show that MSCs derived from adult cynomolgus monkey can undergo spontaneous transformation following in vitro culture. In comparison with MSCs, the spontaneously transformed mesenchymal cells (TMCs) display significantly different growth pattern and morphology, reminiscent of the characteristics of tumor cells. Importantly, TMCs are highly tumorigenic, causing subcutaneous tumors when injected into NOD/SCID mice. Moreover, no multiple differentiation potential of TMCs is observed in vitro or in vivo, suggesting that spontaneously transformed adult stem cells may not necessarily turn into cancer stem cells. These data indicate a direct transformation of cynomolgus monkey MSCs into tumor cells following long-term expansion in vitro. The spontaneous transformation of the cultured cynomolgus monkey MSCs may have important implications for ongoing clinical trials and for models of oncogenesis, thus warranting a more strict assessment of MSCs prior to cell therapy. -- Highlights: Black-Right-Pointing-Pointer Spontaneous transformation of cynomolgus monkey MSCs in vitro. Black-Right-Pointing-Pointer Transformed mesenchymal cells lack multipotency. Black-Right-Pointing-Pointer Transformed mesenchymal cells are highly tumorigenic. Black-Right-Pointing-Pointer Transformed mesenchymal cells do not have the characteristics of cancer stem cells.

  11. Spontaneous transformation of adult mesenchymal stem cells from cynomolgus macaques in vitro

    International Nuclear Information System (INIS)

    Mesenchymal stem cells (MSCs) have shown potential clinical utility in cell therapy and tissue engineering, due to their ability to proliferate as well as to differentiate into multiple lineages, including osteogenic, adipogenic, and chondrogenic specifications. Therefore, it is crucial to assess the safety of MSCs while extensive expansion ex vivo is a prerequisite to obtain the cell numbers for cell transplantation. Here we show that MSCs derived from adult cynomolgus monkey can undergo spontaneous transformation following in vitro culture. In comparison with MSCs, the spontaneously transformed mesenchymal cells (TMCs) display significantly different growth pattern and morphology, reminiscent of the characteristics of tumor cells. Importantly, TMCs are highly tumorigenic, causing subcutaneous tumors when injected into NOD/SCID mice. Moreover, no multiple differentiation potential of TMCs is observed in vitro or in vivo, suggesting that spontaneously transformed adult stem cells may not necessarily turn into cancer stem cells. These data indicate a direct transformation of cynomolgus monkey MSCs into tumor cells following long-term expansion in vitro. The spontaneous transformation of the cultured cynomolgus monkey MSCs may have important implications for ongoing clinical trials and for models of oncogenesis, thus warranting a more strict assessment of MSCs prior to cell therapy. -- Highlights: ► Spontaneous transformation of cynomolgus monkey MSCs in vitro. ► Transformed mesenchymal cells lack multipotency. ► Transformed mesenchymal cells are highly tumorigenic. ► Transformed mesenchymal cells do not have the characteristics of cancer stem cells.

  12. Intervention of oxygen-control ability to radiation sensitivity, cell aging and cell transformation

    International Nuclear Information System (INIS)

    Oxygen is essential for life, and cells have therefore developed numerous adaptive responses to oxygen change. Here, we examined the difference in oxygen-control functions of human (HE), mouse (ME), and Syrian hamster embryo (SHE) cells cultured under different oxygen conditions (0.5%, 2% and 20%), and also examined whether oxygen tensions contributed to cellular lifespan and transformation. HE cells had their replicative lifespan slightly extended under hypoxic (0.5% and 2% oxygen) conditions, but were not immortalized under any of the oxygen concentrations. On the other hand, although ME cells cultured under 20% oxygen tension decreased their proliferation potency temporarily at early stage, all rodent cells were immortalized and acquired anchorage-independency, regardless of oxygen tension. These results suggest that cellular oxygen control function is related to sensitivities cellular immortalization and transformation. To understand intervention of oxygen control ability on cellular immortalization and transformation, we examined the intracellular oxidative level, mitochondria functions and radiation sensitivity. Intracellular oxidative levels of hypoxically cultured rodent cells were significantly enhanced. Mitochondrial membrane potential was altered depend on oxygen tensions, but the change was not parallel to mitochondria number in rodent cells. ME cells were particularly sensitive to oxygen change, and showed a clear oxygen effect on the X-ray survival. However, there was no difference in frequency of radiation-induced micronuclei between HE and ME cells. These results suggest that the response to oxygen change differs markedly in HE and rodent cells. (author)

  13. CELL SHAPE AND HEXOSE TRANSPORT IN NORMAL AND VIRUS-TRANSFORMED CELLS IN CULTURE

    Energy Technology Data Exchange (ETDEWEB)

    Bissell, M.J.; Farson, D.; Tung, A.S.C.

    1976-07-01

    The rate of hexose transport was compared in normal and virus-transformed cells on a monolayer and in suspension. It was shown that: (1) Both trypsin-removed cells and those suspended for an additional day in methyl cellulose had decreased rates of transport and lower available water space when compared with cells on a monolayer. Thus, cell shape affects the overall rate of hexose transport, especially at higher sugar concentrations. (2) Even in suspension, the initial transport rates remained higher in transformed cells with reference to normal cells. Scanning electron micrographs of normal and transformed chick cells revealed morphological differences only in the flat state. This indicates that the increased rate of hexose transport after transformation is not due to a difference in the shape of these cells on a monolayer. The relation between the geometry of cells, transport rates, and growth regulation is undoubtedly very complex, and our knowledge of these relationships is still very elementary. In a recent review on the influence of geometry on control of cell growth, Folkman and Greenspan (1) pointed out that the permeability of cells in a flat versus a spherical state may indeed be very different. The growth properties of cells on a surface and in suspension have been compared often (1-5). However, with one exception. little is known about the changes in transport properties when cell shape is changed. Foster and Pardee (6) demonstrated that the active transport of a-aminoisobutyric acid was reduced 2.5 times in suspension cultures of Chinese hamster cells with respect to the cells grown on a coverslip. They attributed this to the smaller surface area of suspended cells. While it is not clear why active transport should be dependent on the surface area available, it is possible that once the cells assume a spherical configuration, the carrier proteins are redistributed in such a way as to make them less accessible to the substrate. What happens to

  14. Liquid chromatography/Fourier transform IR spectrometry interface flow cell

    Science.gov (United States)

    Johnson, Charles C.; Taylor, Larry T.

    1986-01-01

    A zero dead volume (ZDV) microbore high performance liquid chromatography (.mu.HPLC)/Fourier transform infrared (FTIR) interface flow cell includes an IR transparent crystal having a small diameter bore therein through which a sample liquid is passed. The interface flow cell further includes a metal holder in combination with a pair of inner, compressible seals for directly coupling the thus configured spectrometric flow cell to the outlet of a .mu.HPLC column end fitting to minimize the transfer volume of the effluents exiting the .mu.HPLC column which exhibit excellent flow characteristics due to the essentially unencumbered, open-flow design. The IR beam passes transverse to the sample flow through the circular bore within the IR transparent crystal, which is preferably comprised of potassium bromide (KBr) or calcium fluoride (CaF.sub.2), so as to minimize interference patterns and vignetting encountered in conventional parallel-plate IR cells. The long IR beam pathlength and lensing effect of the circular cross-section of the sample volume in combination with the refractive index differences between the solvent and the transparent crystal serve to focus the IR beam in enhancing sample detection sensitivity by an order of magnitude.

  15. Interferon-induced revertants of ras-transformed cells: resistance to transformation by specific oncogenes and retransformation by 5-azacytidine.

    Science.gov (United States)

    Samid, D; Flessate, D M; Friedman, R M

    1987-01-01

    Prolonged alpha/beta interferon (IFN-alpha/beta) treatment of NIH 3T3 cells transformed by a long terminal repeat-activated Ha-ras proto-oncogene resulted in revertants that maintained a nontransformed phenotype long after IFN treatment had been discontinued. Cloned persistent revertants (PRs) produced large amounts of the ras-encoded p21 and were refractile to transformation by EJras DNA and by transforming retroviruses which carried the v-Ha-ras, v-Ki-ras, v-abl, or v-fes oncogene. Transient treatment either in vitro or in vivo with cytidine analogs that alter gene expression by inhibiting DNA methylation resulted in transformation of PR, but not of NIH 3T3, cells. The PR retransformants reverted again with IFN, suggesting that DNA methylation is involved in IFN-induced persistent reversion. Images PMID:2439904

  16. Enumeration of the Simian Virus 40 Early Region Elements Necessary for Human Cell Transformation

    OpenAIRE

    Hahn, William C.; Scott K Dessain; Brooks, Mary W.; King, Jessie E.; Elenbaas, Brian; Sabatini, David M.; DeCaprio, James A.; Weinberg, Robert A.

    2002-01-01

    While it is clear that cancer arises from the accumulation of genetic mutations that endow the malignant cell with the properties of uncontrolled growth and proliferation, the precise combinations of mutations that program human tumor cell growth remain unknown. The study of the transforming proteins derived from DNA tumor viruses in experimental models of transformation has provided fundamental insights into the process of cell transformation. We recently reported that coexpression of the si...

  17. Chromosomal changes in cultured human epithelial cells transformed by low- and high-LET radiation

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Tracy Chui-hsu; Craise, L.M; Prioleau, J.C.; Stampfer, M.R.; Rhim, J.S.

    1990-11-01

    For a better assessment of radiation risk in space, an understanding of the responses of human cells, especially the epithelial cells, to low- and high-LET radiation is essential. In our laboratory, we have successfully developed techniques to study the neoplastic transformation of two human epithelial cell systems by ionizing radiation. These cell systems are human mammary epithelial cells (H184B5) and human epidermal keratinocytes (HEK). Both cell lines are immortal, anchorage dependent for growth, and nontumorigenic in athymic nude nice. Neoplastic transformation was achieved by irradiation cells successively. Our results showed that radiogenic cell transformation is a multistep process and that a single exposure of ionizing radiation can cause only one step of transformation. It requires, therefore, multihits to make human epithelial cells fully tumorigenic. Using a simple karyotyping method, we did chromosome analysis with cells cloned at various stages of transformation. We found no consistent large terminal deletion of chromosomes in radiation-induced transformants. Some changes of total number of chromosomes, however, were observed in the transformed cells. These transformants provide an unique opportunity for further genetic studies at a molecular level. 15 refs., 9 figs., 2 tabs.

  18. Chromosomal changes in cultured human epithelial cells transformed by low- and high-LET radiation

    Science.gov (United States)

    Craise, L. M.; Prioleau, J. C.; Stampfer, M. R.; Rhim, J. S.; Yang, TC-H (Principal Investigator)

    1992-01-01

    For a better assessment of radiation risk in space, an understanding of the responses of human cells, especially the epithelial cells, to low- and high-LET radiation is essential. In our laboratory, we have successfully developed techniques to study the neoplastic transformation of two human epithelial cell systems by ionizing radiation. These cell systems are human mammary epithelial cells (H184B5) and human epidermal keratinocytes (HEK). Both cell lines are immortal, anchorage dependent for growth, and nontumorigenic in athymic nude mice. Neoplastic transformation was achieved by irradiating cells successively. Our results showed that radiogenic cell transformation is a multistep process and that a single exposure of ionizing radiation can cause only one step of transformation. It requires, therefore, multihits to make human epithelial cells fully tumorigenic. Using a simple karyotyping method, we did chromosome analysis with cells cloned at various stages of transformation. We found no consistent large terminal deletion of chromosomes in radiation-induced transformants. Some changes of total number of chromosomes, however, were observed in the transformed cells. These transformants provide an unique opportunity for further genetic studies at a molecular level.

  19. Sulbutiamine counteracts trophic factor deprivation induced apoptotic cell death in transformed retinal ganglion cells.

    Science.gov (United States)

    Kang, Kui Dong; Majid, Aman Shah Abdul; Kim, Kyung-A; Kang, Kyungsu; Ahn, Hong Ryul; Nho, Chu Won; Jung, Sang Hoon

    2010-11-01

    Sulbutiamine is a highly lipid soluble synthetic analogue of vitamin B(1) and is used clinically for the treatment of asthenia. The aim of our study was to demonstrate whether sulbutiamine is able to attenuate trophic factor deprivation induced cell death to transformed retinal ganglion cells (RGC-5). Cells were subjected to serum deprivation for defined periods and sulbutiamine at different concentrations was added to the cultures. Various procedures (e.g. cell viability assays, apoptosis assay, reactive oxygen species analysis, Western blot analysis, flow cytometric analysis, glutathione (GSH) and glutathione-S-transferase (GST) measurement) were used to demonstrate the effect of sulbutiamine. Sulbutiamine dose-dependently attenuated apoptotic cell death induced by serum deprivation and stimulated GSH and GST activity. Moreover, sulbutiamine decreased the expression of cleaved caspase-3 and AIF. This study demonstrates for the first time that sulbutiamine is able to attenuate trophic factor deprivation induced apoptotic cell death in neuronal cells in culture. PMID:20809085

  20. Histopathological transformation to small-cell lung carcinoma in non-small cell lung carcinoma tumors

    Science.gov (United States)

    Ruiz-Morales, José Manuel; Cano-García, Fernando

    2016-01-01

    Lung cancer is the principal cause of cancer-related death worldwide. The use of targeted therapies, especially tyrosine kinase inhibitors (TKIs), in specific groups of patients has dramatically improved the prognosis of this disease, although inevitably some patients will develop resistance to these drugs during active treatment. The most common cancer-associated acquired mutation is the epidermal growth factor receptor (EGFR) Thr790Met (T790M) mutation. During active treatment with targeted therapies, histopathological transformation to small-cell lung carcinoma (SCLC) can occur in 3–15% of patients with non-small-cell lung carcinoma (NSCLC) tumors. By definition, SCLC is a high-grade tumor with specific histological and genetic characteristics. In the majority of cases, a good-quality hematoxylin and eosin (H&E) stain is enough to establish a diagnosis. Immunohistochemistry (IHC) is used to confirm the diagnosis and exclude other neoplasia such as sarcomatoid carcinomas, large-cell carcinoma, basaloid squamous-cell carcinoma, chronic inflammation, malignant melanoma, metastatic carcinoma, sarcoma, and lymphoma. A loss of the tumor-suppressor protein retinoblastoma 1 (RB1) is found in 100% of human SCLC tumors; therefore, it has an essential role in tumorigenesis and tumor development. Other genetic pathways probably involved in the histopathological transformation include neurogenic locus notch homolog (NOTCH) and achaete-scute homolog 1 (ASCL1). Histological transformation to SCLC can be suspected in NSCLC patients who clinically deteriorate during active treatment. Biopsy of any new lesion in this clinical setting is highly recommended to rule out a SCLC transformation. New studies are trying to assess this histological transformation by noninvasive measures such as measuring the concentration of serum neuron-specific enolase.

  1. Histopathological transformation to small-cell lung carcinoma in non-small cell lung carcinoma tumors.

    Science.gov (United States)

    Dorantes-Heredia, Rita; Ruiz-Morales, José Manuel; Cano-García, Fernando

    2016-08-01

    Lung cancer is the principal cause of cancer-related death worldwide. The use of targeted therapies, especially tyrosine kinase inhibitors (TKIs), in specific groups of patients has dramatically improved the prognosis of this disease, although inevitably some patients will develop resistance to these drugs during active treatment. The most common cancer-associated acquired mutation is the epidermal growth factor receptor (EGFR) Thr790Met (T790M) mutation. During active treatment with targeted therapies, histopathological transformation to small-cell lung carcinoma (SCLC) can occur in 3-15% of patients with non-small-cell lung carcinoma (NSCLC) tumors. By definition, SCLC is a high-grade tumor with specific histological and genetic characteristics. In the majority of cases, a good-quality hematoxylin and eosin (H&E) stain is enough to establish a diagnosis. Immunohistochemistry (IHC) is used to confirm the diagnosis and exclude other neoplasia such as sarcomatoid carcinomas, large-cell carcinoma, basaloid squamous-cell carcinoma, chronic inflammation, malignant melanoma, metastatic carcinoma, sarcoma, and lymphoma. A loss of the tumor-suppressor protein retinoblastoma 1 (RB1) is found in 100% of human SCLC tumors; therefore, it has an essential role in tumorigenesis and tumor development. Other genetic pathways probably involved in the histopathological transformation include neurogenic locus notch homolog (NOTCH) and achaete-scute homolog 1 (ASCL1). Histological transformation to SCLC can be suspected in NSCLC patients who clinically deteriorate during active treatment. Biopsy of any new lesion in this clinical setting is highly recommended to rule out a SCLC transformation. New studies are trying to assess this histological transformation by noninvasive measures such as measuring the concentration of serum neuron-specific enolase.

  2. Initiation of oncogenic transformation in human mammary epithelial cells by charged particles

    Science.gov (United States)

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

    1997-01-01

    Experimental studies have shown that high linear-energy transfer (LET) charged particles can be more effective than x-rays and gamma-rays in inducing oncogenic transformation in cultured cells and tumors in animals. Based on these results, experiments were designed and performed with an immortal human mammary epithelial cell line (H184B5), and several clones transformed by heavy ions were obtained. Cell fusion experiments were subsequently done, and results indicate that the transforming gene(s) is recessive. Chromosome analysis with fluorescence in situ hybridization (FISH) techniques also showed additional translocations in transformed human mammary epithelial cells. In addition, studies with these cell lines indicate that heavy ions can effectively induce deletion, break, and dicentrics. Deletion of tumor suppressor gene(s) and/or formation of translocation through DNA double strand breaks is a likely mechanism for the initiation of oncogenic transformation in human mammary epithelial cells.

  3. Malignant transformation of guinea pig cells after exposure to ultraviolet-irradiated guinea pig cytomegalovirus

    International Nuclear Information System (INIS)

    Guinea pig cells were malignantly transformed in vitro by ultraviolet (uv)-irradiated guinea pig cytomegalovirus (GPCMV). When guinea pig hepatocyte monolayers were infected with uv-irradiated GPCMV, three continuous epithelioid cell lines which grew in soft agarose were established. Two independently derived GPCMV-transformed liver cells and a cell line derived from a soft agarose clone of one of these lines induced invasive tumors when inoculated subcutaneously or intraperitoneally into nude mice. The tumors were sarcomas possibly derived from hepatic stroma or sinusoid. Transformed cell lines were also established after infection of guinea pig hepatocyte monolayers with human cytomegalovirus (HCMV) or simian virus 40 (SV40). These cell lines also formed colonies in soft agarose and induced sarcomas in nude mice. It is concluded that (i) GPCMV can malignantly transform guinea pig cells; (ii) cloning of GPCMV-transformed cells in soft agarose produced cells that induced tumors with a shorter latency period but with no alteration in growth rate or final tumor size; and (iii) the tumors produced by GPCMV-and HCMV-transformed guinea pig cells were more similar to each other in growth rate than to those induced by SV40-transformed guinea pig cells

  4. Modeling human endothelial cell transformation in vascular neoplasias

    Directory of Open Access Journals (Sweden)

    Victoria W. Wen

    2013-09-01

    Full Text Available Endothelial cell (EC-derived neoplasias range from benign hemangioma to aggressive metastatic angiosarcoma, which responds poorly to current treatments and has a very high mortality rate. The development of treatments that are more effective for these disorders will be expedited by insight into the processes that promote abnormal proliferation and malignant transformation of human ECs. The study of primary endothelial malignancy has been limited by the rarity of the disease; however, there is potential for carefully characterized EC lines and animal models to play a central role in the discovery, development and testing of molecular targeted therapies for vascular neoplasias. This review describes molecular alterations that have been identified in EC-derived neoplasias, as well as the processes that underpin the immortalization and tumorigenic conversion of ECs. Human EC lines, established through the introduction of defined genetic elements or by culture of primary tumor tissue, are catalogued and discussed in relation to their relevance as models of vascular neoplasia.

  5. Room temperature electrocompetent bacterial cells improve DNA transformation and recombineering efficiency

    OpenAIRE

    Qiang Tu; Jia Yin; Jun Fu; Jennifer Herrmann; Yuezhong Li; Yulong Yin; Francis Stewart, A.; Rolf Müller; Youming Zhang

    2016-01-01

    Bacterial competent cells are essential for cloning, construction of DNA libraries, and mutagenesis in every molecular biology laboratory. Among various transformation methods, electroporation is found to own the best transformation efficiency. Previous electroporation methods are based on washing and electroporating the bacterial cells in ice-cold condition that make them fragile and prone to death. Here we present simple temperature shift based methods that improve DNA transformation and re...

  6. Methionine restriction inhibits chemically-induced malignant transformation in the BALB/c 3T3 cell transformation assay.

    Science.gov (United States)

    Nicken, Petra; Empl, Michael T; Gerhard, Daniel; Hausmann, Julia; Steinberg, Pablo

    2016-09-01

    High consumption of red meat entails a higher risk of developing colorectal cancer. Methionine, which is more frequently a component of animal proteins, and folic acid are members of the one carbon cycle and as such important players in DNA methylation and cancer development. Therefore, dietary modifications involving altered methionine and folic acid content might inhibit colon cancer development. In the present study, the BALB/c 3T3 cell transformation assay was used to investigate whether methionine and folic acid are able to influence the malignant transformation of mouse fibroblasts after treatment with the known tumour initiator 3-methylcholanthrene. Three different methionine concentrations (representing a -40%, a "normal" and a +40% cell culture medium concentration, respectively) and two different folic acid concentrations (6 and 20 μM) were thereby investigated. Methionine restriction led to a decrease of type III foci, while enhancement of both methionine and folic acid did not significantly increase the cell transformation rate. Interestingly, the focus-lowering effect of methionine was only significant in conjunction with an elevated folic acid concentration. In summary, we conclude that the malignant transformation of mouse fibroblasts is influenced by methionine levels and that methionine restriction could be a possible approach to reduce cancer development.

  7. Methionine restriction inhibits chemically-induced malignant transformation in the BALB/c 3T3 cell transformation assay.

    Science.gov (United States)

    Nicken, Petra; Empl, Michael T; Gerhard, Daniel; Hausmann, Julia; Steinberg, Pablo

    2016-09-01

    High consumption of red meat entails a higher risk of developing colorectal cancer. Methionine, which is more frequently a component of animal proteins, and folic acid are members of the one carbon cycle and as such important players in DNA methylation and cancer development. Therefore, dietary modifications involving altered methionine and folic acid content might inhibit colon cancer development. In the present study, the BALB/c 3T3 cell transformation assay was used to investigate whether methionine and folic acid are able to influence the malignant transformation of mouse fibroblasts after treatment with the known tumour initiator 3-methylcholanthrene. Three different methionine concentrations (representing a -40%, a "normal" and a +40% cell culture medium concentration, respectively) and two different folic acid concentrations (6 and 20 μM) were thereby investigated. Methionine restriction led to a decrease of type III foci, while enhancement of both methionine and folic acid did not significantly increase the cell transformation rate. Interestingly, the focus-lowering effect of methionine was only significant in conjunction with an elevated folic acid concentration. In summary, we conclude that the malignant transformation of mouse fibroblasts is influenced by methionine levels and that methionine restriction could be a possible approach to reduce cancer development. PMID:27427305

  8. Immunofluorescence on avian sarcoma virus-transformed cells: localization of the src gene product.

    Science.gov (United States)

    Rohrschneider, L R

    1979-01-01

    The localization of the avian sarcoma virus src gene product (termed p60src) was examined by indirect immunofluorescence in cells transformed by the Schmidt-Ruppin strain of Rous sarcoma virus, subgroup D (SR-RSV-D). Antiserum to p60src was obtained from rabbits bearing SR-RSV-D-induced tumors, and immunofluorescence was performed on chicken embryo fibroblasts (CEF) transformed with SR-RSV-D, as well as normal rat kidney (NRK) cells transformed by the same virus (termed SR-RK cells). Both acetone and formaldehyde fixation were used for the immunofluorescence tests. The specificity of the anti-tumor serum was first demonstrated in both cell systems by gel electrophoresis of immunoprecipitates prepared from 35S--methionine-labeled cells. Anti-tumor serum precipitated p60src from SR-RSV-D-transformed CEF but not from CEF infected with a transformation-defective mutant of SR-RSV-D. All viral structural proteins and precursors contained in these immunoprecipitates could be eliminated by competition with unlabeled virus. Similar experiments on SR-RK cells indicated that no viral proteins other than p60src were expressed in these cells, and this observation was supported by immunofluorescence tests using antiserum to whole virus. For immunofluorescence localization of p60src, reactions with viral structural proteins were blocked with unlabeled virus. This presaturation step, obligatory for p60src detection in the SR-RSV-D-transformed CEF, was unnecessary when antitumor serum was tested on SR-RK cells, since p60src was the only viral protein detectable in these cells. With acetone-fixed cells, p60src-specific immunofluorescence revealed a characteristic fluorescence pattern which was similar in both cell systems. The principal pattern was diffuse and situated in the cytoplasm. A clear nuclear fluorescence was never observed. Immunofluorescence on formaldehyde-fixed cells also indicated the cytoplasmic location of p60src and revealed a specific subcytoplasmic concentration

  9. Improving Plant Transformation Using Zygote as the Recipient Cell

    Institute of Scientific and Technical Information of China (English)

    Y.H. Yang; H.Q. Tian

    2007-01-01

    @@ Since the first transgenic plant was obtained from tobacco in the 1980's, the transformation of higher plants has been a vigorous field of study using applications of molecular biology. To date, transgenic methods of introducing foreign genes into higher plants include techniques of electrofusion, eletroporation, microinjection and transformation mediated by PEG and Agrobacterium.

  10. Comparison of gene expression profiles in chromate transformed BEAS-2B cells.

    Directory of Open Access Journals (Sweden)

    Hong Sun

    Full Text Available BACKGROUND: Hexavalent chromium [Cr(VI] is a potent human carcinogen. Occupational exposure has been associated with increased risk of respiratory cancer. Multiple mechanisms have been shown to contribute to Cr(VI induced carcinogenesis, including DNA damage, genomic instability, and epigenetic modulation, however, the molecular mechanism and downstream genes mediating chromium's carcinogenicity remain to be elucidated. METHODS/RESULTS: We established chromate transformed cell lines by chronic exposure of normal human bronchial epithelial BEAS-2B cells to low doses of Cr(VI followed by anchorage-independent growth. These transformed cell lines not only exhibited consistent morphological changes but also acquired altered and distinct gene expression patterns compared with normal BEAS-2B cells and control cell lines (untreated that arose spontaneously in soft agar. Interestingly, the gene expression profiles of six Cr(VI transformed cell lines were remarkably similar to each other yet differed significantly from that of either control cell lines or normal BEAS-2B cells. A total of 409 differentially expressed genes were identified in Cr(VI transformed cells compared to control cells. Genes related to cell-to-cell junction were upregulated in all Cr(VI transformed cells, while genes associated with the interaction between cells and their extracellular matrices were down-regulated. Additionally, expression of genes involved in cell proliferation and apoptosis were also changed. CONCLUSION: This study is the first to report gene expression profiling of Cr(VI transformed cells. The gene expression changes across individual chromate exposed clones were remarkably similar to each other but differed significantly from the gene expression found in anchorage-independent clones that arose spontaneously. Our analysis identified many novel gene expression changes that may contribute to chromate induced cell transformation, and collectively this type of

  11. Evaluation of EBV transformation of human memory B-cells isolated by FACS and MACS techniques.

    Science.gov (United States)

    Sadreddini, Sanam; Jadidi-Niaragh, Farhad; Younesi, Vahid; Pourlak, Tala; Afkham, Amir; Shokri, Fazel; Yousefi, Mehdi

    2016-07-01

    Several studies have been performed to develop effective neutralizing monoclonal antibodies. The Epstein-Barr virus (EBV) can efficiently immortalize B-cells to establish lymphoblastoid cell lines (LCL) and so it has been used extensively for transformation of B-cells to produce and secrete immunoglobulin. The present study addressed the effect of TLR7/8 agonist (R848), feeder cells layer and fluorescence-activated cell sorting (FACS) and magnetic-activated cell sorting (MACS) cell separation methods on the transformation efficiency of antibody-producing memory B-cells. For these studies, the antigen used for analyses of antibody formation was the tetanus neurotoxin (TeNT) derived from Clostridium tetani. The results here showed that employing an HFFF.PI6 feeder cell layer, R848 agonist and FACS-mediated purification of memory B-cells led to increased transformation efficiency. Altogether, the effects of the R848 and the feeder cells provided an efficient method for EBV transformation of human B-cells. Moreover, there was an advantage in using FACS sorting of B-cells over the MACS method in the context of EBV transformation and immortalization of precursors of antigen-specific B-cells. PMID:27043044

  12. The input-output transformation of the hippocampal granule cells: from grid cells to place fields.

    Science.gov (United States)

    de Almeida, Licurgo; Idiart, Marco; Lisman, John E

    2009-06-10

    Grid cells in the rat medial entorhinal cortex fire (periodically) over the entire environment. These cells provide input to hippocampal granule cells whose output is characterized by one or more small place fields. We sought to understand how this input-output transformation occurs. Available information allows simulation of this process with no freely adjustable parameters. We first examined the spatial distribution of excitation in granule cells produced by the convergence of excitatory inputs from randomly chosen grid cells. Because the resulting summation depends on the number of inputs, it is necessary to use a realistic number (approximately 1200) and to take into consideration their 20-fold variation in strength. The resulting excitation maps have only modest peaks and valleys. To analyze how this excitation interacts with inhibition, we used an E%-max (percentage of maximal suprathreshold excitation) winner-take-all rule that describes how gamma-frequency inhibition affects firing. We found that simulated granule cells have firing maps that have one or more place fields whose size and number approximates those observed experimentally. A substantial fraction of granule cells have no place fields, as observed experimentally. Because the input firing rates and synaptic properties are known, the excitatory charge into granule cells could be calculated (2-3 pC) and was found to be only somewhat larger than required to fire granule cells (1 pC). We conclude that the input-output transformation of dentate granule does not depend strongly on synaptic modification; place field formation can be understood in terms of simple summation of randomly chosen excitatory inputs, in conjunction with a winner-take-all network mechanism.

  13. Responsiveness of fetal rat brain cells to glia maturation factor during neoplastic transformation in cell culture

    DEFF Research Database (Denmark)

    Haugen, A; Laerum, O D; Bock, E

    1981-01-01

    The effect of partially purified extracts from adult pig brains containing a glia maturation protein factor (BE) has been investigated on neural cells during carcinogenesis. Pregnant BD IX-rats were given a single transplacental dose of the carcinogen ethylnitrosourea (EtNU) on the 18th day...... of gestation. The brains of the treated fetuses were transferred to cell culture and underwent neoplastic transformation with a characteristic sequence of phenotypic alterations which could be divided into five different stages. During the first 40 days after explantation (stage I & II) BE induced...

  14. Transformation of UV-hypersensitive Chinese hamster ovary cell mutants with UV-irradiated plasmids

    International Nuclear Information System (INIS)

    Transfection of UV-hypersensitive, DNA repair-deficient Chinese hamster ovary (CHO) cell lines and parental, repair-proficient CHO cells with UV-irradiated pHaprt-1 or pSV2gpt plasmids resulted in different responses by recipient cell lines to UV damage in transfected DNA. Unlike results reported for human cells, UV irradiation of transfecting DNA did not stimulate genetic transformation of CHO recipient cells. In repair-deficient CHO cells, proportionally fewer transformants were produced with increasing UV damage than in repair-proficient cells in transfections with UV-irradiated hamster adenine phosphoribosyltransferase (APRT) gene contained in plasmid pHaprt-1. Transfection of CHO cells with UV-irradiated pSV2gpt resulted in neither decline in transformation frequencies in repair-deficient cell lines relative to repair-proficient cells nor stimulation of genetic transformation by UV damage in the plasmid. Blot hybridization analysis of DNA samples isolated from transformed cells showed no dramatic changes in copy number or arrangement of transfected plasmid DNA with increasing UV dose. The authors conclude responses of recipient cells to UV-damaged transfecting plasmids depend on type of recipient cell and characteristics of the genetic sequence used for transfection. (author)

  15. Binase induces apoptosis of transformed myeloid cells and does not induce T-cell immune response.

    Science.gov (United States)

    Ilinskaya, Olga N; Zelenikhin, Pavel V; Petrushanko, Irina Yu; Mitkevich, Vladimir A; Prassolov, Vladimir S; Makarov, Alexander A

    2007-10-01

    Microbial RNases along with such animal RNases as onconase and BS-RNase are a promising basis for developing new antitumor drugs. We have shown that the Bacillus intermedius RNase (binase) induces selective apoptosis of transformed myeloid cells. It attacks artificially expressing activated c-Kit myeloid progenitor FDC cells and chronic myelogenous leukemia cells K562. Binase did not induce apoptosis in leukocytes of healthy donors and in normal myeloid progenitor cells. The inability of binase to initiate expression of activation markers CD69 and IFN-gamma in CD4+ and CD8+ T-lymphocytes testifies that enzyme is devoid of superantigenic properties. Altogether, these results demonstrate that binase possesses therapeutic opportunities for treatment of genotyped human neoplasms expressing activated kit.

  16. Ouabain sensitivity is linked to ras -transformation in human HOS cells

    International Nuclear Information System (INIS)

    Mouse cells transformed by the retroviral oncogene v-Ki- ras are significantly more sensitive to the toxic effects of 1mM ouabain than are their nontransformed counterparts. We have extended these findings to a human cell line (HOS). HOS cells (ATCC CRL 1543) are relatively resistant to treatment with 1 microM ouabain while KHOS cells (transformed by Kirsten murine sarcoma virus) are extremely sensitive. Two flat revertant cell lines isolated from the KHOS line and lacking the v- ras gene sequences are resistant to ouabain. This effect may be observed morphologically and can also be demonstrated by dye exclusion and plating efficiency tests. In addition, the toxic effects of ouabain may be rapidly and efficiently quantitated in a 51Cr-release assay. This differential lethality may be used to enrich the proportion of non-transformed revertants in populations of mutagen-treated transformed cells

  17. Objective scoring of transformed foci in BALB/c 3T3 cell transformation assay by statistical image descriptors

    OpenAIRE

    Urani, Chiara; Corvi, Raffaella; CALLEGARO G.; Stefanini, Federico Mattia

    2013-01-01

    In vitro cell transformation assays (CTAs) have been shown to model important stages of in vivo carcinogenesis and have the potential to predict carcinogenicity in humans. Advantages of CTAs are their ability of revealing both genotoxic and non-genotoxic carcinogens while reducing both experimental costs and the number of animals used. The endpoint of the CTA is foci formation, and requires classification under light microscopy based on morphology. Thus current limitations for the wide ado...

  18. Optimization of energy-consuming pathways towards rapid growth in HPV-transformed cells.

    Directory of Open Access Journals (Sweden)

    Sarit Mizrachy-Schwartz

    Full Text Available Cancer is a complex, multi-step process characterized by misregulated signal transduction and altered metabolism. Cancer cells divide faster than normal cells and their growth rates have been reported to correlate with increased metabolic flux during cell transformation. Here we report on progressive changes in essential elements of the biochemical network, in an in vitro model of transformation, consisting of primary human keratinocytes, human keratinocytes immortalized by human papillomavirus 16 (HPV16 and passaged repeatedly in vitro, and the extensively-passaged cells subsequently treated with the carcinogen benzo[a]pyrene. We monitored changes in cell growth, cell size and energy metabolism. The more transformed cells were smaller and divided faster, but the cellular energy flux was unchanged. During cell transformation the protein synthesis network contracted, as shown by the reduction in key cap-dependent translation factors. Moreover, there was a progressive shift towards internal ribosome entry site (IRES-dependent translation. The switch from cap to IRES-dependent translation correlated with progressive activation of c-Src, an activator of AMP-activated protein kinase (AMPK, which controls energy-consuming processes, including protein translation. As cellular protein synthesis is a major energy-consuming process, we propose that the reduction in cell size and protein amount provide energy required for cell survival and proliferation. The cap to IRES-dependent switch seems to be part of a gradual optimization of energy-consuming mechanisms that redirects cellular processes to enhance cell growth, in the course of transformation.

  19. Cell Dynamics Simulation of Kolmogorov-Johnson-Mehl-Avrami Kinetics of Phase Transformation

    OpenAIRE

    Iwamatsu, Masao; Nakamura, Masato

    2005-01-01

    In this study, we use the cell dynamics method to test the validity of the Kormogorov-Johnson-Mehl-Avrami (KJMA) theory of phase transformation. This cell dynamics method is similar to the well-known phase-field model, but it is a more simple and efficient numerical method for studying various scenarios of phase transformation in a unified manner. We find that the cell dynamics method reproduces the time evolution of the volume fraction of the transformed phase predicted by the KJMA theory. S...

  20. Neoplastic transformation of chimpanzee cells induced by adenovirus type 12--simian virus 40 hybrid virus.

    OpenAIRE

    Rhim, J S; Trimmer, R; Arnstein, P; Huebner, R J

    1981-01-01

    The adenovirus 12--simian virus 40 hybrid virus produced neoplastic transformation of chimpanzee skin fibroblasts in vitro. The transformed fibroblasts showed morphological alteration and became permanent lines. The transformed cells contained both adenovirus 12 and simian virus 40 large tumor antigens and were virus producers. However at passage 9, one line (WES) was found to be a nonproducer, producing neither infectious virus nor virus-specific antigen detectable by the complement fixation...

  1. Efficient retrovirus-mediated transfer of cell-cycle control genes to transformed cells

    Directory of Open Access Journals (Sweden)

    B.E. Strauss

    1999-07-01

    Full Text Available The use of gene therapy continues to be a promising, yet elusive, alternative for the treatment of cancer. The origins of cancer must be well understood so that the therapeutic gene can be chosen with the highest chance of successful tumor regression. The gene delivery system must be tailored for optimum transfer of the therapeutic gene to the target tissue. In order to accomplish this, we study models of G1 cell-cycle control in both normal and transformed cells in order to understand the reasons for uncontrolled cellular proliferation. We then use this information to choose the gene to be delivered to the cells. We have chosen to study p16, p21, p53 and pRb gene transfer using the pCL-retrovirus. Described here are some general concepts and specific results of our work that indicate continued hope for the development of genetically based cancer treatments.

  2. Alterations of FHIT Gene and P16 Gene in Nickel Transformed Human Bronchial Epithelial Cells

    Institute of Scientific and Technical Information of China (English)

    WEI-DONG JI; JIA-KUN CHEN; JIA-CHUN LU; ZHONG-LIANG WU; FEI YI; SU-MEI FENG

    2006-01-01

    To study the alterations of FHIT gene and P16 gene in malignant transformed human bronchial epithelial cells induced by crystalline nickel sulfide using an immoral human bronchial epithelial cell line, and to explore the molecular mechanism of nickel carcinogenesis. Methods 16HBE cells were treated 6 times with different concentrations of NiS in vitro, and the degree of malignant transformation was determined by assaying the anchorage-independent growth and tumorigenicity. Malignant transformed cells and tumorigenic cells were examined for alterations of FHIT gene and P16 gene using RT-PCR, DNA sequencing, silver staining PCR-SSCP and Western blotting. Results NiS-treated cells exhibited overlapping growth. Compared with that of negative control cells, soft agar colony formation efficiency of NiS-treated cells showed significant increases (P<0.01) and dose-dependent effects. NiS-treated cells could form tumors in nude mice, and a squamous cell carcinoma was confirmed by histopathological examination. No mutation of exon 2 and exons 2-3, no abnormal expression in p16 gene and mutation of FHIT exons 5-8 and exons 1-4 or exons 5-9 were observed in transformed cells and tumorigenic cells. However, aberrant transcripts or loss of expression of the FHIT gene and Fhit protein was observed in transformed cells and tumorigenic cells. One of the aberrant transcripts in the FHIT gene was confirmed to have a deletion of exon 6, exon 7, exon 8, and an insertion of a 36 bp sequence replacing exon 6-8. Conclusions The FHIT gene rather than the P16 gene, plays a definite role in nickel carcinogenesis. Alterations of the FHIT gene induced by crystalline NiS may be a molecular event associated with carcinogen, chromosome fragile site instability and cell malignant transformation. FHIT may be an important target gene activated by nickel and other exotic carcinogens.

  3. Friend leukemia virus transformed cells exposed to microgravity in the presence of DMSO (7-IML-1)

    Science.gov (United States)

    Cogoli, Augusto

    1992-01-01

    The purpose of this experiment is to study the adaptation of living cells to microgravity. The in vitro transformation of Friend cells by Dimethylsufoxide (DMSO) is a good model for the study of cell differentiation and protein biosynthesis. Cultures of cells will be prepared shortly before launch. Once in space, transformation will be induced by injection of DMSO. One set of cultures will be chemically fixed with glutaraldehyde for electron microscope investigations; another set will be preserved for determining the amount of hemogloben produced and the extent of cell proliferation.

  4. Fucolipid metabolism as a function of cell population density in normal and murine sarcoma virus-transformed rat cells

    International Nuclear Information System (INIS)

    The incorporation of isotopically labeled fucose into the lipids of normal and murine sarcoma virus-transformed rat cells as a function of cell population density was examined. When normal cells were seeded at low cell density, the levels of the major fucolipids, i.e., fucolipids III and IV, were substantially reduced, but then they increased as the cells approached confluency. This variation in synthesis of fucolipids III and IV appeared to be primarily related to cell density and not to cell growth. Chase experiments revealed that the reduced level of fucolipids III and IV in sparse normal cells is due to decreased synthesis rather than to increased catabolism. In contrast to the observations with normal rat cells, the high level of fucolipid III and the low level of fucolipid IV in murine sarcoma virus-transformed rat cells was shown to be independent of cell population density

  5. Tumor suppressors Sav/Scrib and oncogene Ras regulate stem cell transformation in adult Drosophila Malpighian Tubules

    OpenAIRE

    Zeng, Xiankun; Singh, Shree Ram; Hou, David; Steven X Hou

    2010-01-01

    An increasing body of evidence suggests that tumors might originate from a few transformed cells that share many properties with normal stem cells. However, it remains unclear how normal stem cells are transformed into cancer stem cells. Here, we demonstrated that mutations causing the loss of tumor suppressor Sav or Scrib or activation of the oncogene Ras transform normal stem cells into cancer stem cells through a multistep process in the adult Drosophila Malpighian Tubules (MTs). In wild-t...

  6. Bhas 42 cell transformation activity of cigarette smoke condensate is modulated by selenium and arsenic.

    Science.gov (United States)

    Han, Sung Gu; Pant, Kamala; Bruce, Shannon W; Gairola, C Gary

    2016-04-01

    Cigarette smoking remains a major health risk worldwide. Development of newer tobacco products requires the use of quantitative toxicological assays. Recently, v-Ha-ras transfected BALB/c3T3 (Bhas 42) cell transformation assay was established that simulates the two-stage animal tumorigenesis model and measures tumor initiating and promoting activities of chemicals. The present study was performed to assess the feasibility of using this Bhas 42 cell transformation assay to determine the initiation and promotion activities of cigarette smoke condensate (CSC) and its water soluble fraction. Further, the modulating effects of selenium and arsenic on cigarette smoke-induced cell transformation were investigated. Dimethyl sulfoxide (DMSO) and water extracts of CSC (CSC-D and CSC-W, respectively) were tested at concentrations of 2.5-40 µg mL(-1) in the initiation or promotion assay formats. Initiation protocol of the Bhas 42 assay showed a 3.5-fold increase in transformed foci at 40 µg mL(-1) of CSC-D but not CSC-W. The promotion phase of the assay yielded a robust dose response with CSC-D (2.5-40 µg mL(-1)) and CSC-W (20-40 µg mL(-1)). Preincubation of cells with selenium (100 nM) significantly reduced CSC-induced increase in cell transformation in initiation assay. Co-treatment of cells with a sub-toxic dose of arsenic significantly enhanced cell transformation activity of CSC-D in promotion assay. The results suggest a presence of both water soluble and insoluble tumor promoters in CSC, a role of oxidative stress in CSC-induced cell transformation, and usefulness of Bhas 42 cell transformation assay in comparing tobacco product toxicities and in studying the mechanisms of tobacco carcinogenesis.

  7. SPONTANEOUS TRANSFORMATION OF CULTURED PORCINE BONE MARROW STROMAL CELLS

    DEFF Research Database (Denmark)

    Zou, Lijin; Zou, Xuenong; Li, Haisheng;

    INTRODUCTION Recently, the possibility that tumors originate from cancer stem cells (CSCs) has been proposed. Stem cells and CSCs share certain features such as self-renewal and differentiation potential. The aim of this study was to evaluate whether bone marrow stromal cells (BMSC) after long-te...

  8. Role of reactive oxygen species in arsenic-induced transformation of human lung bronchial epithelial (BEAS-2B) cells

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Zhuo, E-mail: zhuo.zhang@uky.edu [Graduate Center for Toxicology, University of Kentucky, Lexington, KY 40536 (United States); Pratheeshkumar, Poyil; Budhraja, Amit; Son, Young-Ok [Center for Research on Environmental Diseases, University of Kentucky, Lexington, KY 40536 (United States); Kim, Donghern [Graduate Center for Toxicology, University of Kentucky, Lexington, KY 40536 (United States); Shi, Xianglin [Center for Research on Environmental Diseases, University of Kentucky, Lexington, KY 40536 (United States)

    2015-01-09

    Highlights: • Short term exposure of cells to arsenic causes ROS generation. • Chronical exposure of cells to arsenic causes malignant cell transformation. • Inhibition of ROS generation reduces cell transformation by arsenic. • Arsenic-transformed cells exhibit reduced capacity of generating ROS. • Arsenic-transformed cells exhibit increased levels of antioxidants. - Abstract: Arsenic is an environmental carcinogen, its mechanisms of carcinogenesis remain to be investigated. Reactive oxygen species (ROS) are considered to be important. A previous study (Carpenter et al., 2011) has measured ROS level in human lung bronchial epithelial (BEAS-2B) cells and arsenic-transformed BEAS-2B cells and found that ROS levels were higher in transformed cells than that in parent normal cells. Based on these observations, the authors concluded that cell transformation induced by arsenic is mediated by increased cellular levels of ROS. This conclusion is problematic because this study only measured the basal ROS levels in transformed and parent cells and did not investigate the role of ROS in the process of arsenic-induced cell transformation. The levels of ROS in arsenic-transformed cells represent the result and not the cause of cell transformation. Thus question concerning whether ROS are important in arsenic-induced cell transformation remains to be answered. In the present study, we used expressions of catalase (antioxidant against H{sub 2}O{sub 2}) and superoxide dismutase 2 (SOD2, antioxidant against O{sub 2}{sup ·−}) to decrease ROS level and investigated their role in the process of arsenic-induced cell transformation. Our results show that inhibition of ROS by antioxidant enzymes decreased arsenic-induced cell transformation, demonstrating that ROS are important in this process. We have also shown that in arsenic-transformed cells, ROS generation was lower and levels of antioxidants are higher than those in parent cells, in a disagreement with the previous

  9. Malignant transformation of ectopic pancreatic cells in the duodenal wall

    Institute of Scientific and Technical Information of China (English)

    Roberto; Bini; Paolo; Voghera; Alberto; Tapparo; Raffaele; Nunziata; Andrea; Demarchi; Matteo; Capocefalo; Renzo; Leli

    2010-01-01

    Ectopic pancreas (EP) is the relatively uncommon presence of pancreatic tissue outside the normal location of the pancreas. This condition is usually asymptomatic and rarely complicated by pancreatitis and malignant transformation. A few cases of neoplastic phenomena that developed from EP into the duodenal wall are described in the literature. Herein we report a case of gastric outlet obstruction due to adenocarcinoma arising from EP of the duodenal wall. The patient underwent a Whipple's procedure and had...

  10. Timescale of silver nanoparticle transformation in neural cell cultures impacts measured cell response

    Energy Technology Data Exchange (ETDEWEB)

    Hume, Stephanie L.; Chiaramonti, Ann N.; Rice, Katherine P.; Schwindt, Rani K. [National Institute of Standards and Technology (NIST), Applied Chemicals and Materials Division (United States); MacCuspie, Robert I. [National Institute of Standards and Technology (NIST), Materials Measurement Science Division (United States); Jeerage, Kavita M., E-mail: jeerage@boulder.nist.gov [National Institute of Standards and Technology (NIST), Applied Chemicals and Materials Division (United States)

    2015-07-15

    Both serum protein concentration and ionic strength are important factors in nanoparticle transformation within cell culture environments. However, silver nanoparticles are not routinely tracked at their working concentration in the specific medium used for in vitro toxicology studies. Here we evaluated the transformation of electrostatically stabilized citrate nanoparticles (C-AgNPs) and sterically stabilized polyvinylpyrrolidone nanoparticles (PVP-AgNPs) in a low-serum (∼ 0.2 mg/mL bovine serum albumin) culture medium, while measuring the response of rat cortex neural progenitor cells, which differentiate in this culture environment. After 24 h, silver nanoparticles at concentrations up to 10 µg/mL did not affect adenosine triphosphate levels, whereas silver ions decreased adenosine triphosphate levels at concentrations of 1.1 µg/mL or higher. After 240 h, both silver nanoparticles, as well as silver ion, unambiguously decreased adenosine triphosphate levels at concentrations of 1 and 1.1 µg/mL, respectively, suggesting particle dissolution. Particle transformation was investigated in 1:10 diluted, 1:2 diluted, or undiluted differentiation medium, all having an identical protein concentration, to separate the effect of serum protein stabilization from ionic strength destabilization. Transmission electron microscopy images indicated that particles in 1:10 medium were not surrounded by proteins, whereas particles became clustered within a non-crystalline protein matrix after 24 h in 1:2 medium and at 0 h in undiluted medium. Despite evidence for a protein corona, particles were rapidly destabilized by high ionic strength media. Polyvinylpyrrolidone increased the stability of singly dispersed particles compared to citrate ligands; however, differences were negligible after 4 h in 1:2 medium or after 1 h in undiluted medium. Thus low-serum culture environments do not provide sufficient colloidal stability for long-term toxicology studies with citrate

  11. Timescale of silver nanoparticle transformation in neural cell cultures impacts measured cell response

    International Nuclear Information System (INIS)

    Both serum protein concentration and ionic strength are important factors in nanoparticle transformation within cell culture environments. However, silver nanoparticles are not routinely tracked at their working concentration in the specific medium used for in vitro toxicology studies. Here we evaluated the transformation of electrostatically stabilized citrate nanoparticles (C-AgNPs) and sterically stabilized polyvinylpyrrolidone nanoparticles (PVP-AgNPs) in a low-serum (∼ 0.2 mg/mL bovine serum albumin) culture medium, while measuring the response of rat cortex neural progenitor cells, which differentiate in this culture environment. After 24 h, silver nanoparticles at concentrations up to 10 µg/mL did not affect adenosine triphosphate levels, whereas silver ions decreased adenosine triphosphate levels at concentrations of 1.1 µg/mL or higher. After 240 h, both silver nanoparticles, as well as silver ion, unambiguously decreased adenosine triphosphate levels at concentrations of 1 and 1.1 µg/mL, respectively, suggesting particle dissolution. Particle transformation was investigated in 1:10 diluted, 1:2 diluted, or undiluted differentiation medium, all having an identical protein concentration, to separate the effect of serum protein stabilization from ionic strength destabilization. Transmission electron microscopy images indicated that particles in 1:10 medium were not surrounded by proteins, whereas particles became clustered within a non-crystalline protein matrix after 24 h in 1:2 medium and at 0 h in undiluted medium. Despite evidence for a protein corona, particles were rapidly destabilized by high ionic strength media. Polyvinylpyrrolidone increased the stability of singly dispersed particles compared to citrate ligands; however, differences were negligible after 4 h in 1:2 medium or after 1 h in undiluted medium. Thus low-serum culture environments do not provide sufficient colloidal stability for long-term toxicology studies with citrate

  12. The transforming parasite Theileria co-opts host cell mitotic and central spindles to persist in continuously dividing cells.

    Directory of Open Access Journals (Sweden)

    Conrad von Schubert

    Full Text Available The protozoan parasite Theileria inhabits the host cell cytoplasm and possesses the unique capacity to transform the cells it infects, inducing continuous proliferation and protection against apoptosis. The transforming schizont is a multinucleated syncytium that resides free in the host cell cytoplasm and is strictly intracellular. To maintain transformation, it is crucial that this syncytium is divided over the two daughter cells at each host cell cytokinesis. This process was dissected using different cell cycle synchronization methods in combination with the targeted application of specific inhibitors. We found that Theileria schizonts associate with newly formed host cell microtubules that emanate from the spindle poles, positioning the parasite at the equatorial region of the mitotic cell where host cell chromosomes assemble during metaphase. During anaphase, the schizont interacts closely with host cell central spindle. As part of this process, the schizont recruits a host cell mitotic kinase, Polo-like kinase 1, and we established that parasite association with host cell central spindles requires Polo-like kinase 1 catalytic activity. Blocking the interaction between the schizont and astral as well as central spindle microtubules prevented parasite segregation between the daughter cells during cytokinesis. Our findings provide a striking example of how an intracellular eukaryotic pathogen that evolved ways to induce the uncontrolled proliferation of the cells it infects usurps the host cell mitotic machinery, including Polo-like kinase 1, one of the pivotal mitotic kinases, to ensure its own persistence and survival.

  13. Agrobacterium-mediated transformation of Vitis Cv. Monastrell suspension-cultured cells: Determination of critical parameters.

    Science.gov (United States)

    Chu, Mingyu; Quiñonero, Carmen; Akdemir, Hülya; Alburquerque, Nuria; Pedreño, María Ángeles; Burgos, Lorenzo

    2016-05-01

    Although some works have explored the transformation of differentiated, embryogenic suspension-cultured cells (SCC) to produce transgenic grapevine plants, to our knowledge this is one of the first reports on the efficient transformation of dedifferentiated Vitis vinifera cv Monastrell SCC. This protocol has been developed using the sonication-assisted Agrobacterium-mediated transformation (SAAT) method. A construct harboring the selectable nptII and the eyfp/IV2 marker genes was used in the study and transformation efficiencies reached over 50 independent transformed SCC per gram of infected cells. Best results were obtained when cells were infected at the exponential phase. A high density plating (500 mg/dish) gave significantly better results. As selective agent, kanamycin was inefficient for the selection of Monastrell transformed SCC since wild type cells were almost insensitive to this antibiotic whereas application of paromomycin resulted in very effective selection. Selected eyfp-expressing microcalli were grown until enough tissue was available to scale up a new transgenic SCC. These transgenic SCC lines were evaluated molecularly and phenotypically demonstrating the presence and integration of both transgenes, the absence of Agrobacterium contamination and the ability of the transformed SCC to grow in highly selective liquid medium. The methodology described here opens the possibility of improving the production of valuable metabolites. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:725-734, 2016.

  14. Novel cellular genes essential for transformation of endothelial cells by Kaposi's sarcoma-associated herpesvirus.

    Science.gov (United States)

    Raggo, Camilo; Ruhl, Rebecca; McAllister, Shane; Koon, Henry; Dezube, Bruce J; Früh, Klaus; Moses, Ashlee V

    2005-06-15

    Kaposi's sarcoma-associated herpesvirus (KSHV) is involved in the development of lymphoproliferative diseases and Kaposi's sarcoma. The oncogenicity of this virus is reflected in vitro by its ability to transform B cells and endothelial cells. Infection of dermal microvascular endothelial cells (DMVEC) transforms the cells from a cobblestone-like monolayer to foci-forming spindle cells. This transformation is accompanied by dramatic changes in the cellular transcriptome. Known oncogenes, such as c-Kit, are among the KSHV-induced host genes. We previously showed that c-Kit is an essential cellular component of the KSHV-mediated transformation of DMVEC. Here, we test the hypothesis that the transformation process can be used to discover novel oncogenes. When expression of a panel of KSHV-induced cellular transcripts was inhibited with antisense oligomers, we observed inhibition of DMVEC proliferation and foci formation using antisense molecules to RDC1 and Neuritin. We further showed that transformation of KSHV-infected DMVEC was inhibited by small interfering RNA directed at RDC1 or Neuritin. Ectopic expression of Neuritin in NIH 3T3 cells resulted in changes in cell morphology and anchorage-independent growth, whereas RDC1 ectopic expression significantly increased cell proliferation. In addition, both RDC1- and Neuritin-expressing cells formed tumors in nude mice. RDC1 is an orphan G protein-coupled receptor, whereas Neuritin is a growth-promoting protein known to mediate neurite outgrowth. Neither gene has been previously implicated in tumorigenesis. Our data suggest that KSHV-mediated transformation involves exploitation of the hitherto unrealized oncogenic properties of RDC1 and Neuritin. PMID:15958552

  15. Role of Pin1 in UVA-induced cell proliferation and malignant transformation in epidermal cells

    International Nuclear Information System (INIS)

    Highlights: → Pin1 expression is enhanced by low energy UVA irradiation in both skin tissues of hairless mice and JB6 C141 epidermal cells. → UVA irradiation increases activator protein-1 activity and cyclin D1 in a Pin1-dependent manner. → UVA potentiates EGF-inducible, anchorage-independent growth of epidermal cells, and this is suppressed by Pin1 inhibition or by anti-oxidant. -- Abstract: Ultraviolet A (UVA) radiation (λ = 320-400 nm) is considered a major cause of human skin cancer. Pin1, a peptidyl prolyl isomerase, is overexpressed in most types of cancer tissues and plays an important role in cell proliferation and transformation. Here, we demonstrated that Pin1 expression was enhanced by low energy UVA (300-900 mJ/cm2) irradiation in both skin tissues of hairless mice and JB6 C141 epidermal cells. Exposure of epidermal cells to UVA radiation increased cell proliferation and cyclin D1 expression, and these changes were blocked by Pin1 inhibition. UVA irradiation also increased activator protein-1 (AP-1) minimal reporter activity and nuclear levels of c-Jun, but not c-Fos, in a Pin1-dependent manner. The increases in Pin1 expression and in AP-1 reporter activity in response to UVA were abolished by N-acetylcysteine (NAC) treatment. Finally, we found that pre-exposure of JB6 C141 cells to UVA potentiated EGF-inducible, anchorage-independent growth, and this effect was significantly suppressed by Pin1inhibition or by NAC.

  16. Conditionally reprogrammed normal and transformed mouse mammary epithelial cells display a progenitor-cell-like phenotype.

    Directory of Open Access Journals (Sweden)

    Francisco R Saenz

    Full Text Available Mammary epithelial (ME cells cultured under conventional conditions senesce after several passages. Here, we demonstrate that mouse ME cells isolated from normal mammary glands or from mouse mammary tumor virus (MMTV-Neu-induced mammary tumors, can be cultured indefinitely as conditionally reprogrammed cells (CRCs on irradiated fibroblasts in the presence of the Rho kinase inhibitor Y-27632. Cell surface progenitor-associated markers are rapidly induced in normal mouse ME-CRCs relative to ME cells. However, the expression of certain mammary progenitor subpopulations, such as CD49f+ ESA+ CD44+, drops significantly in later passages. Nevertheless, mouse ME-CRCs grown in a three-dimensional extracellular matrix gave rise to mammary acinar structures. ME-CRCs isolated from MMTV-Neu transgenic mouse mammary tumors express high levels of HER2/neu, as well as tumor-initiating cell markers, such as CD44+, CD49f+, and ESA+ (EpCam. These patterns of expression are sustained in later CRC passages. Early and late passage ME-CRCs from MMTV-Neu tumors that were implanted in the mammary fat pads of syngeneic or nude mice developed vascular tumors that metastasized within 6 weeks of transplantation. Importantly, the histopathology of these tumors was indistinguishable from that of the parental tumors that develop in the MMTV-Neu mice. Application of the CRC system to mouse mammary epithelial cells provides an attractive model system to study the genetics and phenotype of normal and transformed mouse epithelium in a defined culture environment and in vivo transplant studies.

  17. Chemicals as the Sole Transformers of Cell Fate

    Science.gov (United States)

    Ebrahimi, Behnam

    2016-01-01

    Forced expression of lineage-specific transcription factors in somatic cells can result in the generation of different cell types in a process named direct reprogramming, bypassing the pluripotent state. However, the introduction of transgenes limits the therapeutic applications of the produced cells. Numerous small-molecules have been introduced in the field of stem cell biology capable of governing self-renewal, reprogramming, transdifferentiation and regeneration. These chemical compounds are versatile tools for cell fate conversion toward desired outcomes. Cell fate conversion using small-molecules alone (chemical reprogramming) has superiority over arduous traditional genetic techniques in several aspects. For instance, rapid, transient, and reversible effects in activation and inhibition of functions of specific proteins are of the profits of small-molecules. They are cost-effective, have a long half-life, diversity on structure and function, and allow for temporal and flexible regulation of signaling pathways. Additionally, their effects could be adjusted by fine-tuning concentrations and combinations of different small-molecules. Therefore, chemicals are powerful tools in cell fate conversion and study of stem cell and chemical biology in vitro and in vivo. Moreover, transgene-free and chemical-only transdifferentiation approaches provide alternative strategies for the generation of various cell types, disease modeling, drug screening, and regenerative medicine. The current review gives an overview of the recent findings concerning transdifferentiation by only small-molecules without the use of transgenes. PMID:27426081

  18. Transformation of quiescent adult oligodendrocyte precursor cells into malignant glioma through a multistep reactivation process.

    Science.gov (United States)

    Galvao, Rui Pedro; Kasina, Anita; McNeill, Robert S; Harbin, Jordan E; Foreman, Oded; Verhaak, Roel G W; Nishiyama, Akiko; Miller, C Ryan; Zong, Hui

    2014-10-01

    How malignant gliomas arise in a mature brain remains a mystery, hindering the development of preventive and therapeutic interventions. We previously showed that oligodendrocyte precursor cells (OPCs) can be transformed into glioma when mutations are introduced perinatally. However, adult OPCs rarely proliferate compared with their perinatal counterparts. Whether these relatively quiescent cells have the potential to transform is unknown, which is a critical question considering the late onset of human glioma. Additionally, the premalignant events taking place between initial mutation and a fully developed tumor mass are particularly poorly understood in glioma. Here we used a temporally controllable Cre transgene to delete p53 and NF1 specifically in adult OPCs and demonstrated that these cells consistently give rise to malignant gliomas. To investigate the transforming process of quiescent adult OPCs, we then tracked these cells throughout the premalignant phase, which revealed a dynamic multistep transformation, starting with rapid but transient hyperproliferative reactivation, followed by a long period of dormancy, and then final malignant transformation. Using pharmacological approaches, we discovered that mammalian target of rapamycin signaling is critical for both the initial OPC reactivation step and late-stage tumor cell proliferation and thus might be a potential target for both glioma prevention and treatment. In summary, our results firmly establish the transforming potential of adult OPCs and reveal an actionable multiphasic reactivation process that turns slowly dividing OPCs into malignant gliomas.

  19. Inhibition of the growth of transformed and neoplastic cells by the dipeptide carnosine.

    OpenAIRE

    Holliday, R; McFarland, G. A.

    1996-01-01

    Human diploid fibroblasts growth normally in medium containing physiological concentrations of the naturally occurring dipeptide carnosine (beta-alanyl-L-histidine). These concentrations are cytotoxic to transformed and neoplastic cells lines in modified Eagle medium (MEM), whereas these cells grow vigorously in Dulbecco's modified Eagle medium (DMEM) containing carnosine. This difference is due to the presence of 1 mM sodium pyruvate in DMEM. Seven human cell lines and two rodent cell lines ...

  20. Differential behaviour of normal, transformed and Fanconi's anemia lymphoblastoid cells to modeled microgravity

    Directory of Open Access Journals (Sweden)

    Sancandi Monica

    2010-07-01

    Full Text Available Abstract Background Whether microgravity might influence tumour growth and carcinogenesis is still an open issue. It is not clear also if and how normal and transformed cells are differently solicited by microgravity. The present study was designed to verify this issue. Methods Two normal, LB and HSC93, and two transformed, Jurkat and 1310, lymphoblast cell lines were used as representative for the two conditions. Two lymphoblast lines from Fanconi's anemia patients group A and C (FA-A and FA-C, respectively, along with their isogenic corrected counterparts (FA-A-cor and FA-C-cor were also used. Cell lines were evaluated for their proliferative ability, vitality and apoptotic susceptibility upon microgravity exposure in comparison with unexposed cells. Different parameters correlated to energy metabolism, glucose consumption, mitochondrial membrane potential (MMP, intracellular ATP content, red-ox balance and ability of the cells to repair the DNA damage product 8-OHdG induced by the treatment of the cells with 20 mM KBrO3 were also evaluated. Results Transformed Jurkat and 1310 cells appear resistant to the microgravitational challenge. On the contrary normal LB and HSC93 cells display increased apoptotic susceptibility, shortage of energy storages and reduced ability to cope with oxidative stress. FA-A and FA-C cells appear resistant to microgravity exposure, analogously to transformed cells. FA corrected cells did shown intermediate sensitivity to microgravity exposure suggesting that genetic correction does not completely reverts cellular phenotype. Conclusions In the light of the reported results microgravity should be regarded as an harmful condition either when considering normal as well as transformed cells. Modeled microgravity and space-based technology are interesting tools in the biomedicine laboratory and offer an original, useful and unique approach in the study of cellular biochemistry and in the regulation of metabolic pathways.

  1. Transformation-deformation bands in C60 after the treatment in a shear diamond anvil cell

    Science.gov (United States)

    Kulnitskiy, B. A.; Blank, V. D.; Levitas, V. I.; Perezhogin, I. A.; Popov, M. Yu; Kirichenko, A. N.; Tyukalova, E. V.

    2016-04-01

    The C60 fullerene has been investigated by high-resolution transmission electron microscopy and electron energy loss spectroscopy in a shear diamond anvil cell after applying pressure and shear deformation treatment of fcc phase. Shear transformation-deformation bands are revealed consisting of shear-strain-induced nanocrystals of linearly polymerized fullerene and polytypes, the triclinic, monoclinic, and hcp C60, fragments of amorphous structures, and voids. Consequently, after pressure release, the plastic strain retains five high pressure phases, which is potentially important for their engineering applications. Localized shear deformation initially seems contradictory because high pressure phases of C60 are stronger than the initial low pressure phase. However, this was explained by transformation-induced plasticity during localized phase transformations. It occurs due to a combination of applied stresses and internal stresses from a volume reduction during phase transformations. Localized phase transformations and plastic shear deformation promote each other, which produce positive mechanochemical feedback and cascading transformation-deformation processes. Since the plastic shear in a band is much larger than is expected based on the torsion angle, five phase transformations occur in the same region with no transformation outside the band. The results demonstrate that transformation kinetics cannot be analyzed in terms of prescribed shear, and methods to measure local shear should be developed.

  2. Enhanced Agrobacterium-mediated transformation efficiencies in monocot cells is associated with attenuated defense responses.

    Science.gov (United States)

    Zhang, Wan-Jun; Dewey, Ralph E; Boss, Wendy; Phillippy, Brian Q; Qu, Rongda

    2013-02-01

    Plant defense responses can lead to altered metabolism and even cell death at the sites of Agrobacterium infection, and thus lower transformation frequencies. In this report, we demonstrate that the utilization of culture conditions associated with an attenuation of defense responses in monocot plant cells led to highly improved Agrobacterium-mediated transformation efficiencies in perennial ryegrass (Lolium perenne L.). The removal of myo-inositol from the callus culture media in combination with a cold shock pretreatment and the addition of L-Gln prior to and during Agrobacterium-infection resulted in about 84 % of the treated calluses being stably transformed. The omission of myo-inositol from the callus culture media was associated with the failure of certain pathogenesis related genes to be induced after Agrobacterium infection. The addition of a cold shock and supplemental Gln appeared to have synergistic effects on infection and transformation efficiencies. Nearly 60 % of the stably transformed calluses regenerated into green plantlets. Calluses cultured on media lacking myo-inositol also displayed profound physiological and biochemical changes compared to ones cultured on standard growth media, such as reduced lignin within the cell walls, increased starch and inositol hexaphosphate accumulation, enhanced Agrobacterium binding to the cell surface, and less H(2)O(2) production after Agrobacterium infection. Furthermore, the cold treatment greatly reduced callus browning after infection. The simple modifications described in this report may have broad application for improving genetic transformation of recalcitrant monocot species.

  3. UV-stimulation of DNA-mediated transformation of human cells.

    NARCIS (Netherlands)

    M. van Duin (Mark); A. Westerveld (Andries); J.H.J. Hoeijmakers (Jan)

    1985-01-01

    textabstractIrradiation of dominant marker DNA with UV light (150 to 1,000 J/m2) was found to stimulate the transformation of human cells by this marker from two- to more than fourfold. This phenomenon is also displayed by xeroderma pigmentosum cells (complementation groups A and F), which are defic

  4. Mechanisms of chemical modification of neoplastic cell transformation by ionizing radiation

    International Nuclear Information System (INIS)

    During space travel, astronauts will be continuously exposed to ionizing radiation; therefore, it is necessary to minimize the radiation damage by all possible means. The authors' studies show that DMSO (when present during irradiation) can protect cells from being killed and transformed by X rays and that low concentration of DMSO can reduce the transformation frequency significantly when it is applied to cells, even many days after irradiation. The process of neoplastic cell transformation is a complicated one and includes at least two different stages: induction and expression. DMSO apparently can modify the radiation damage during both stages. There are several possible mechanisms for the DMSO effect: (1) changing the cell membrane structure and properties; (2) inducing cell differentiation by acting on DNA; and (3) scavanging free radicals in the cell. Recent studies with various chemical agents, e.g., 5-azacytidine, dexamethane, rhodamin-123, etc., indicate that the induction of cell differentiation by acting on DNA may be an important mechanism for the suppression of expression of neoplastic cell transformation by DMSO

  5. Low creep and hysteresis silicon load cell based on a force-to-liquid pressure transformation

    NARCIS (Netherlands)

    Zwijze, Robert A.F.; Wiegerink, Remco J.; Lammerink, Theo S.J.; Elwenspoek, Miko

    1998-01-01

    Important problems in load cells are creep and hysteresis. Expensive high grade steels are used in order to reduce these effects. In this paper a silicon load cell design is presented which is based on a force-to-liquid-pressure transformation. The design is insensitive to hysteresis and creep, can

  6. Study of cancer cell lines with Fourier transform infrared (FTIR)/vibrational absorption (VA) spectroscopy

    DEFF Research Database (Denmark)

    Uceda Otero, E. P.; Eliel, G. S. N.; Fonseca, E. J. S.;

    2013-01-01

    In this work we have used Fourier transform infrared (FTIR) / vibrational absorption (VA) spectroscopy to study two cancer cell lines: the Henrietta Lacks (HeLa) human cervix carcinoma and 5637 human bladder carcinoma cell lines. Our goal is to experimentally investigate biochemical changes and d...

  7. A conundrum in molecular toxicology: molecular and biological changes during neoplastic transformation of human cells.

    Science.gov (United States)

    Milo, G E; Shuler, C F; Lee, H; Casto, B C

    1995-12-01

    The process of multistage carcinogenesis lends itself to the concept that the effects of carcinogens are mediated through dose-related, multi-hit, linear changes. Multiple in vitro model systems have been developed that are designed to examine the cellular changes associated with the progression of cells through the different stages in the process; however, these systems may have inherent limitations due to the cell lines used for these studies, the manner of assessing the effects of the carcinogens, and the subsequent growth and differentiation of the exposed cells. Each of these variables results in increasing levels of uncertainty relative to the correlation of the events with the actual process of human tumor development. Therefore, the prediction of the ultimate effect of any carcinogen is difficult. Moreover, relationships between individual biological endpoints resulting from carcinogen treatment appear at best to be approximations. The presence of an activated carcinogen inside the cell can give rise to multiple outcomes, only some of which may be critical events. For example, site-specific modification of the 12th and 13th codons of H-ras is different than that in the adjacent 14th and 15th codons. It is interesting to speculate what effect these differences might have on a biological outcome, e.g., transformation to anchorage-independent growth. The use of different model systems to examine the effects of activated carcinogens also creates additional problems. Comparisons of in vitro transformed cells with similar cells isolated from human tumors indicate that the culture environment appears to influence the expression of a particular phenotype, in that human tumor cells in culture express many of the same parameters as those found in cells transformed with carcinogens in vitro. If the process of transformation is linear, then less aggressive phenotypes should progress to a more aggressive transformed stage. However, in carcinogen-transformed human cells

  8. Neoplastic transformation of a human prostate epithelial cell line by the v-Ki-ras oncogene.

    Science.gov (United States)

    Parda, D S; Thraves, P J; Kuettel, M R; Lee, M S; Arnstein, P; Kaighn, M E; Rhim, J S; Dritschilo, A

    1993-01-01

    Investigations of mechanisms of human prostate carcinogenesis are limited by the unavailability of a suitable in vitro model system. We have demonstrated that an immortal, but nontumorigenic, human epithelial cell line (267B1) established from fetal prostate tissue can be malignantly transformed by a biological carcinogen, and can serve as a useful model for investigations of the progression steps of carcinogenesis. Activated Ki-ras was introduced into 267B1 cells by infection with the Kirsten murine sarcoma virus. Morphological alterations and anchorage-independent growth were observed; when cells were injected into nude mice, poorly differentiated adenocarcinomas developed. These findings represent the first evidence of malignant transformation of human prostate epithelial cells in culture, and support a role for Ki-ras activation in a multistep process for prostate neoplastic transformation.

  9. Post-transcriptional regulation of connexin43 in H-Ras-transformed cells.

    Directory of Open Access Journals (Sweden)

    Mustapha Kandouz

    Full Text Available Connexin43 (Cx43 expression is lost in cancer cells and many studies have reported that Cx43 is a tumor suppressor gene. Paradoxically, in a cellular NIH3T3 model, we have previously shown that Ha-Ras-mediated oncogenic transformation results in increased Cx43 expression. Although the examination of transcriptional regulation revealed essential regulatory elements, it could not solve this paradox. Here we studied post-transcriptional regulation of Cx43 expression in cancer using the same model in search of novel gene regulatory elements. Upon Ras transformation, both Cx43 mRNA stability and translation efficiency were increased. We investigated the role of Cx43 mRNA 3' and 5'Untranslated regions (UTRs and found an opposing effect; a 5'UTR-driven positive regulation is observed in Ras-transformed cells (NIH-3T3(Ras, while the 3'UTR is active only in normal NIH-3T3(Neo cells and completely silenced in NIH-3T3(Ras cells. Most importantly, we identified a previously unknown regulatory element within the 3'UTR, named S1516, which accounts for this 3'UTR-mediated regulation. We also examined the effect of other oncogenes and found that Ras- and Src-transformed cells show a different Cx43 UTRs post-transcriptional regulation than ErbB2-transformed cells, suggesting distinct regulatory pathways. Next, we detected different patterns of S1516 RNA-protein complexes in NIH-3T3(Neo compared to NIH-3T3(Ras cells. A proteomic approach identified most of the S1516-binding proteins as factors involved in post-transcriptional regulation. Building on our new findings, we propose a model to explain the discrepancy between the Cx43 expression in Ras-transformed NIH3T3 cells and the data in clinical specimens.

  10. Construction and characteristics of a transformed lepidopteran cell clone expressing baculovirus p35

    Institute of Scientific and Technical Information of China (English)

    ZHENG Guiling; LI Changyou; LI Guoxun; WANG Ping; Robert R. Granados

    2005-01-01

    A transformed cell line was constructed from Mythimna separata cells Ms7311 by lipofection method. TMs7311 cells were generated using a double selection technique involving a selection in the antibiotic Zeocin, followed by a second round of selection by exhibiting cell characterization. A cell clone expressing p35 was obtained with high level of AcMNPV and recombinant proteins. Compared with wild type Ms7311 cells, the cell clone showed increased resistance to Actinamycin D-induced apoptosis and a profound resistance to nutrient development (PBS). When the cell clone was infected with recombinant baculoviruses expressing secreted alkaline phosphatase (SEAP) and β-galactosi- dase, expression of the recombinant proteins from TMs7311 cells exceeded that from parental Ms7311 cells. Production of budded virus and occlusion body was significantly higher than that from parental cells Ms7311.

  11. Morphological transformation of an established Syrian hamster dermal cell with the anti-tussive agent noscapine.

    Science.gov (United States)

    Porter, R; Parry, E M; Parry, J M

    1992-05-01

    Following exposure to the alkaloid noscapine hydrochloride over a concentration range of 10-120 micrograms/ml immortal cultures of Syrian hamster dermal fibroblasts were shown to undergo morphological transformation. The resultant transformed foci produced cultures which were anchorage independent as confirmed by soft agar tests. Karyotype analysis of a noscapine transformed colony demonstrated an increase in chromosome number compared to the immortal culture and the non-random duplication of a translocated chromosome 9 previously identified in the immortal culture. These data indicate that noscapine, which has previously been shown to be a spindle inhibitor and inducer of polyploidy in cultured cells, is capable of inducing in vitro cell transformation. Such data indicate a carcinogenic potential for this widely used cough suppressant. PMID:1602976

  12. Room temperature electrocompetent bacterial cells improve DNA transformation and recombineering efficiency.

    Science.gov (United States)

    Tu, Qiang; Yin, Jia; Fu, Jun; Herrmann, Jennifer; Li, Yuezhong; Yin, Yulong; Stewart, A Francis; Müller, Rolf; Zhang, Youming

    2016-01-01

    Bacterial competent cells are essential for cloning, construction of DNA libraries, and mutagenesis in every molecular biology laboratory. Among various transformation methods, electroporation is found to own the best transformation efficiency. Previous electroporation methods are based on washing and electroporating the bacterial cells in ice-cold condition that make them fragile and prone to death. Here we present simple temperature shift based methods that improve DNA transformation and recombineering efficiency in E. coli and several other gram-negative bacteria thereby economizing time and cost. Increased transformation efficiency of large DNA molecules is a significant advantage that might facilitate the cloning of large fragments from genomic DNA preparations and metagenomics samples. PMID:27095488

  13. Manipulating mammalian cell by phase transformed titanium surface fabricated through ultra-short pulsed laser synthesis.

    Science.gov (United States)

    Chinnakkannu Vijayakumar, Sivaprasad; Venkatakrishnan, Krishnan; Tan, Bo

    2016-01-15

    Developing cell sensitive indicators on interacting substrates that allows specific cell manipulation by a combination of physical, chemical or mechanical cues is a challenge for current biomaterials. Hence, various fabrication approaches have been created on a variety of substrates to mimic or create cell specific cues. However, to achieve cell specific cues a multistep process or a post-chemical treatment is often necessitated. So, a simple approach without any chemical or biological treatment would go a long way in developing bio-functionalized substrates to effectively modulate cell adhesion and interaction. The present investigation is aimed to study the manipulative activity induced by phase transformed titanium surface. An ultra-short laser is used to fabricate the phase transformed titanium surface where a polymorphic titanium oxide phases with titanium monoxide (TiO), tri-titanium oxide (Ti3O) and titanium dioxide (TiO2) have been synthesized on commercially pure titanium. Control over oxide phase transformed area was demonstrated via a combination of laser scanning time (laser pulse interaction time) and laser pulse widths (laser pulse to pulse separation time). The interaction of phase transformed titanium surface with NIH3T3 fibroblasts and MC3T3-E1 osteoblast cells developed a new bio-functionalized platforms on titanium based biomaterials to modulate cell migration and adhesion. The synthesized phase transformed titanium surface on the whole appeared to induce directional cues for cell migration with unique preferential cell adhesion unseen by other fabrication approaches. The precise bio-functionalization controllability exhibited during fabrication offers perceptible edge for developing a variety of smart bio-medical devices, implants and cardiovascular stents where the need in supressing specific cell adhesion and proliferation is of great demand.

  14. Inherited susceptibility to retrovirus-induced transformation of Gardner syndrome cells.

    OpenAIRE

    Rasheed, S; Rhim, J S; Gardner, E J

    1983-01-01

    Skin fibroblasts from patients with Gardner syndrome (GS), those with familial polyposis coli (FPC), and spouse or unrelated controls were karyotyped and tested for various growth properties including susceptibility to transformation by viral or chemical agents. Our results indicated that based on the higher susceptibility to retrovirus-induced transformation and chromosomal aneuploidy, the GS and FPC cells could be distinguished from those of the general population with more than 70% accurac...

  15. Extracellular localization of catalase is associated with the transformed state of malignant cells.

    Science.gov (United States)

    Böhm, Britta; Heinzelmann, Sonja; Motz, Manfred; Bauer, Georg

    2015-12-01

    Oncogenic transformation is dependent on activated membrane-associated NADPH oxidase (NOX). However, the resultant extracellular superoxide anions are also driving the NO/peroxynitrite and the HOCl pathway, which eliminates NOX-expressing transformed cells through selective apoptosis induction. Tumor progression is dependent on dominant interference with intercellular apoptosis-inducing ROS signaling through membrane-associated catalase, which decomposes H2O2 and peroxynitrite and oxidizes NO. Particularly, the decomposition of extracellular peroxynitrite strictly requires membrane-associated catalase. We utilized small interfering RNA (siRNA)-mediated knockdown of catalase and neutralizing antibodies directed against the enzyme in combination with challenging H2O2 or peroxynitrite to determine activity and localization of catalase in cells from three distinct steps of multistage oncogenesis. Nontransformed cells did not generate extracellular superoxide anions and only showed intracellular catalase activity. Transformed cells showed superoxide anion-dependent intercellular apoptosis-inducing ROS signaling in the presence of suboptimal catalase activity in their membrane. Tumor cells exhibited tight control of intercellular apoptosis-inducing ROS signaling through a high local concentration of membrane-associated catalase. These data demonstrate that translocation of catalase to the outside of the cell membrane is already associated with the transformation step. A strong local increase in the concentration of membrane-associated catalase is achieved during tumor progression and is controlled by tumor cell-derived H2O2 and by transglutaminase.

  16. Transient expression of minimum linear gene cassettes in onion epidermal cells via direct transformation.

    Science.gov (United States)

    Cheng, Yun-Qing; Yang, Jun; Xu, Feng-Ping; An, Li-Jia; Liu, Jian-Feng; Chen, Zhi-Wen

    2009-12-01

    A new method without any special devices for direct transformation of linear gene cassettes was developed. Its feasibility was verified through 5'-fluorescent dye (fluorescein isothiocyanate, FITC)-labeled fluorescent tracing and transient expression of a gus reporter gene. Minimal linear gene cassettes, containing necessary regulation elements and a gus reporter gene, was prepared by polymerase chain reaction and dissolved in transformation buffer solution to 100 ng/mL. The basic transformation solution used was Murashige and Skoog basal salt mixture (MS) liquid medium. Hypertonic pretreatment of explants and transformation cofactors, including Ca(2+), surfactant assistants, Agrobacterium LBA4404 cell culture on transformation efficiency were evaluated. Prior to the incubation of the explants and target linear cassette in each designed transformation solution for 3 h, the onion low epidermal explants were pre-cultured in darkness at 27 degrees C for 48 h and then transferred to MS solid media for 72 h. FITC-labeled linear DNA was used to trace the delivery of DNA entry into the cell and the nuclei. By GUS staining and flow-cytometry-mediated fluorescent detection, a significant increase of the ratios of fluorescent nuclei as well as expression of the gus reporter gene was observed by each designed transformation solution. This potent and feasible method showed prospective applications in plant transgenic research. PMID:19255730

  17. Adenovirus E1A/E1B Transformed Amniotic Fluid Cells Support Human Cytomegalovirus Replication

    Directory of Open Access Journals (Sweden)

    Natascha Krömmelbein

    2016-02-01

    Full Text Available The human cytomegalovirus (HCMV replicates to high titers in primary human fibroblast cell cultures. A variety of primary human cells and some tumor-derived cell lines do also support permissive HCMV replication, yet at low levels. Cell lines established by transfection of the transforming functions of adenoviruses have been notoriously resistant to HCMV replication and progeny production. Here, we provide first-time evidence that a permanent cell line immortalized by adenovirus type 5 E1A and E1B (CAP is supporting the full HCMV replication cycle and is releasing infectious progeny. The CAP cell line had previously been established from amniotic fluid cells which were likely derived from membranes of the developing fetus. These cells can be grown under serum-free conditions. HCMV efficiently penetrated CAP cells, expressed its immediate-early proteins and dispersed restrictive PML-bodies. Viral DNA replication was initiated and viral progeny became detectable by electron microscopy in CAP cells. Furthermore, infectious virus was released from CAP cells, yet to lower levels compared to fibroblasts. Subviral dense bodies were also secreted from CAP cells. The results show that E1A/E1B expression in transformed cells is not generally repressive to HCMV replication and that CAP cells may be a good substrate for dense body based vaccine production.

  18. A Methodology for Cell Merging Circuit Transformation on Post-placement High Speed Design

    Directory of Open Access Journals (Sweden)

    Diana Tan Hui Lyn

    2012-01-01

    Full Text Available This paper proposes a localize circuit transformation algorithm to further optimize the post-placement netlist in order to improve the overall timing of a design. The proposed algorithm reduces the total cell delay and net delay of timing violation paths by replacing a small group of cells (form up by two to three cells that are placed close to each other with a functional equivalent standard cell available in the technology library. The algorithm has been implemented and applied to a number of optimized postplacement netlists which have went through conventional post-placement circuit transformation optimization processes such as gate relocation, cell re-sizing, repeater insertion and cell replication. The experimental results show that on average, this algorithm is able to further improve the timing of the optimized post-placement netlist by 27.75%, while keeping the design area increase by 0.2%.

  19. Oncogene activation induces metabolic transformation resulting in insulin-independence in human breast cancer cells.

    Directory of Open Access Journals (Sweden)

    Aliccia Bollig-Fischer

    Full Text Available Normal breast epithelial cells require insulin and EGF for growth in serum-free media. We previously demonstrated that over expression of breast cancer oncogenes transforms MCF10A cells to an insulin-independent phenotype. Additionally, most breast cancer cell lines are insulin-independent for growth. In this study, we investigated the mechanism by which oncogene over expression transforms MCF10A cells to an insulin-independent phenotype. Analysis of the effects of various concentrations of insulin and/or IGF-I on proliferation of MCF10A cells demonstrated that some of the effects of insulin were independent from those of IGF-I, suggesting that oncogene over expression drives a true insulin-independent proliferative phenotype. To test this hypothesis, we examined metabolic functions of insulin signaling in insulin-dependent and insulin-independent cells. HER2 over expression in MCF10A cells resulted in glucose uptake in the absence of insulin at a rate equal to insulin-induced glucose uptake in non-transduced cells. We found that a diverse set of oncogenes induced the same result. To gain insight into how HER2 oncogene signaling affected increased insulin-independent glucose uptake we compared HER2-regulated gene expression signatures in MCF10A and HER2 over expressing MCF10A cells by differential analysis of time series gene expression data from cells treated with a HER2 inhibitor. This analysis identified genes specifically regulated by the HER2 oncogene, including VAMP8 and PHGDH, which have known functions in glucose uptake and processing of glycolytic intermediates, respectively. Moreover, these genes specifically implicated in HER2 oncogene-driven transformation are commonly altered in human breast cancer cells. These results highlight the diversity of oncogene effects on cell regulatory pathways and the importance of oncogene-driven metabolic transformation in breast cancer.

  20. Fourier transform infrared spectroscopic study of intact cells of the nitrogen-fixing bacterium Azospirillum brasilense

    Science.gov (United States)

    Kamnev, A. A.; Ristić, M.; Antonyuk, L. P.; Chernyshev, A. V.; Ignatov, V. V.

    1997-06-01

    The data of Fourier transform infrared (FTIR) spectroscopic measurements performed on intact cells of the soil nitrogen-fixing bacterium Azospirillum brasilense grown in a standard medium and under the conditions of an increased metal uptake are compared and discussed. The structural FTIR information obtained is considered together with atomic absorption spectrometry (AAS) data on the content of metal cations in the bacterial cells. Some methodological aspects concerning preparation of bacterial cell samples for FTIR measurements are also discussed.

  1. Silencing KRAS overexpression in arsenic-transformed prostate epithelial and stem cells partially mitigates malignant phenotype.

    Science.gov (United States)

    Ngalame, Ntube N O; Tokar, Erik J; Person, Rachel J; Waalkes, Michael P

    2014-12-01

    Inorganic arsenic is a human carcinogen that likely targets the prostate. Chronic arsenic exposure malignantly transforms the RWPE-1 human prostate epithelial line to chronic arsenic exposed-prostate epithelial (CAsE-PE) cells, and a derivative normal prostate stem cell (SC) line, WPE-stem to arsenic-cancer SCs (As-CSCs). The KRAS oncogene is highly overexpressed in CAsE-PE cells and activation precedes transformation, inferring mechanistic significance. As-CSCs also highly overexpress KRAS. Thus, we hypothesize KRAS activation is key in causing and maintaining an arsenic-induced malignant phenotype, and hence, KRAS knockdown (KD) may reverse this malignant phenotype. RNA interference using shRNAmirs to obtain KRAS KD was used in CAsE-PE and As-CSC cells. Cells analyzed 2 weeks post transduction showed KRAS protein decreased to 5% of control after KD, confirming stable KD. KRAS KD decreased phosphorylated ERK, indicating inhibition of RAS/ERK signaling, a proliferation/survival pathway activated with arsenic transformation. Secreted metalloproteinase (MMP) activity was increased by arsenic-induced malignant transformation, but KRAS KD from 4 weeks on decreased secreted MMP-9 activity by 50% in As-CSCs. Colony formation, a characteristic of cancer cells, was decreased in both KRAS KD transformants. KRAS KD also decreased the invasive capacity of both cell types. KRAS KD decreased proliferation in As-CSCs, consistent with loss of rapid tumor growth. Genes predicted to impact cell proliferation (eg, Cyclin D1, p16, and p21) changed accordingly in both KD cell types. Thus, KRAS silencing impacts aspects of arsenic-induced malignant phenotype, inducing loss of many typical cancer characteristics particularly in As-CSCs.

  2. Down-regulation of Rab5 decreases characteristics associated with maintenance of cell transformation

    International Nuclear Information System (INIS)

    The early endosomal protein Rab5 is highly expressed in tumor samples, although a causal relationship between Rab5 expression and cell transformation has not been established. Here, we report the functional effects of targeting endogenous Rab5 with specific shRNA sequences in different tumor cell lines. Rab5 down-regulation in B16-F10 cells decreased tumor formation by subcutaneous injection into C57/BL6 mice. Accordingly, Rab5 targeting in B16-F10 and A549, but not MDA-MB-231 cells was followed by decreased cell proliferation, increased apoptosis and decreased anchorage-independent growth. These findings suggest that Rab5 expression is required to maintain characteristics associated with cell transformation. - Highlights: • Rab5 is important to the maintenance of cell transformation characteristics. • Down-regulation of Rab5 decreases cell proliferation and increases apoptosis in different cancer cells. • Rab5 is required for anchorage-independent growth and tumorigenicity in-vivo

  3. Down-regulation of Rab5 decreases characteristics associated with maintenance of cell transformation

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Patricio; Soto, Nicolás [Institute for Research in Dental Sciences, Faculty of Dentistry, Universidad de Chile, Santiago (Chile); Díaz, Jorge [Institute for Research in Dental Sciences, Faculty of Dentistry, Universidad de Chile, Santiago (Chile); Center for Molecular Studies of the Cell, Institute of Biomedical Sciences (ICBM), Faculty of Medicine, Universidad de Chile, Santiago (Chile); Mendoza, Pablo [Institute for Research in Dental Sciences, Faculty of Dentistry, Universidad de Chile, Santiago (Chile); Díaz, Natalia [Institute for Research in Dental Sciences, Faculty of Dentistry, Universidad de Chile, Santiago (Chile); Center for Molecular Studies of the Cell, Institute of Biomedical Sciences (ICBM), Faculty of Medicine, Universidad de Chile, Santiago (Chile); Quest, Andrew F.G. [Center for Molecular Studies of the Cell, Institute of Biomedical Sciences (ICBM), Faculty of Medicine, Universidad de Chile, Santiago (Chile); Advanced Center for Chronic Diseases (ACCDiS), Faculty of Medicine, Universidad de Chile, Santiago (Chile); Torres, Vicente A., E-mail: vatorres@med.uchile.cl [Institute for Research in Dental Sciences, Faculty of Dentistry, Universidad de Chile, Santiago (Chile); Advanced Center for Chronic Diseases (ACCDiS), Faculty of Medicine, Universidad de Chile, Santiago (Chile)

    2015-08-21

    The early endosomal protein Rab5 is highly expressed in tumor samples, although a causal relationship between Rab5 expression and cell transformation has not been established. Here, we report the functional effects of targeting endogenous Rab5 with specific shRNA sequences in different tumor cell lines. Rab5 down-regulation in B16-F10 cells decreased tumor formation by subcutaneous injection into C57/BL6 mice. Accordingly, Rab5 targeting in B16-F10 and A549, but not MDA-MB-231 cells was followed by decreased cell proliferation, increased apoptosis and decreased anchorage-independent growth. These findings suggest that Rab5 expression is required to maintain characteristics associated with cell transformation. - Highlights: • Rab5 is important to the maintenance of cell transformation characteristics. • Down-regulation of Rab5 decreases cell proliferation and increases apoptosis in different cancer cells. • Rab5 is required for anchorage-independent growth and tumorigenicity in-vivo.

  4. Program Area of Interest: Fuel Transformer Solid Oxide Fuel Cell

    Energy Technology Data Exchange (ETDEWEB)

    Norman Bessette; Douglas S. Schmidt; Jolyon Rawson; Rhys Foster; Anthony Litka

    2006-02-01

    The following report documents the technical approach and conclusions made by Acumentrics Corporation during latest budget period toward the development of a low cost 10kW tubular SOFC power system. The present program, guided under direction from the National Energy Technology Laboratory of the US DOE, is a nine-year cost shared Cooperative Agreement totaling close to $74M funded both by the US DOE as well as Acumentrics Corporation and its partners. The latest budget period ran from July of 2005 through December 2005. Work focused on cell technology enhancements as well as BOP and power electronics improvements and overall system design. Significant progress was made in increasing cell power enhancements as well as decreasing material cost in a drive to meet the SECA cost targets. The following report documents these accomplishments in detail as well as the layout plans for further progress in next budget period.

  5. Malignant transformation and treatment of cystic mixed germ cell tumor

    Institute of Scientific and Technical Information of China (English)

    Yapeng Zhao; Hongyu Duan; Qinghui Zhang; Bingxin Shi; Hui Liang; Yuqi Zhang

    2016-01-01

    Objective: The authors report an extremely unusual presentation and management of a children pineal mixed germ cell tumor mainly composed of immature teratoma, aiming to summarize main theraptic points by literature review. Methods: A cystic lesion located in the rear of third ventricle in a child was detected 3 years ago with no other therapy performed except for a ventriculo-peritoneal shunt. During the following 3 years, intermitted regular brain MRI demonstrated no evidence of lesion aggrandizement. However from 20 days before admission to our institute the patient began to present acutely with exacerbating clinical symptoms meanwhile brain MRI showed signs of abrupt revulsions of initial lesion without any incentive cause. Neurological examination revealed a significant rising of serum tumor marker level. Then surgical resection was performed immediately after admission which was followed by correlative two-course chemotherapy. Results: Postoperative brain MRI demonstrated totally removing of the lesion in rear of third ventricle. Serum tumor marker level decreased remarkably after surgery and declined to normal level after two-course chemotherapy. No obvious neurological deficit occurred except for short-term memory difficulty which gradually recovered within two weeks. Soon after the second course chemotherapy the patient was currently asymptomatic and returned to school. Conclusions: (1) To ensure definitive diagnosis and proper therapecutic protocols benefit from grasping clinical features of mixed germ cell tumor. (2) Overall preoperative investigation including serum tumor marker level is as critical as neurological imaging examination. (3) Surgical excision is confirmed to be the key modality of treatment. With the regarding of mixed germ cell tumor, never highlight total resection too much. (4) Postoperative adjuvant chemotherapy is recommended as further intensive treatment to improve the prognosis of mix germ cell tumor.

  6. Introduction of transformed chloroplasts from tobacco into petunia by asymmetric cell fusion.

    Science.gov (United States)

    Sigeno, Asako; Hayashi, Sugane; Terachi, Toru; Yamagishi, Hiroshi

    2009-11-01

    Plastid engineering technique has been established only in Nicotiana tabacum, and the widespread application is severely limited so far. In order to exploit a method to transfer the genetically transformed plastomes already obtained in tobacco into other plant species, somatic cell fusion was conducted between a plastome transformant of tobacco and a cultivar of petunia (Petunia hybrida). A tobacco strain whose plastids had been transformed with aadA (a streptomycin/spectinomycin adenylyltransferase gene) and mdar [a gene for monodehydroascorbate reductase (MDAR)] and a petunia variety, 'Telstar', were used as cell fusion partners. An efficient regeneration system from the protoplasts of both the parents, and effectiveness of selection for the aadA gene with spectinomycin were established before the cell fusion. In addition, the influence of UV irradiation on the callus development from the protoplasts and shoot regeneration of tobacco was investigated. Protoplasts were cultured after cell fusion treatment with polyethylene glycol, and asymmetric somatic cybrids were selected using the aadA gene as a marker. Although many shoots of tobacco that had escaped the UV irradiation regenerated, several shoots possessing the morphology of petunia and the resistance to spectinomycin were obtained. Molecular analyses of the petunia type regenerants demonstrated that they had the nuclear and mitochondrial genomes derived from petunia besides the chloroplasts of tobacco transformed with aadA and mdar. Furthermore, it was ascertained that mdar was transcribed in the somatic cybrids. The results indicate the success in intergeneric transfer of transformed plastids of tobacco into petunia. PMID:19727738

  7. Influence of fungal elicitation on glycyrrhizin production in transformed cell cultures of Abrus precatorius Linn

    Directory of Open Access Journals (Sweden)

    Vijai Singh Karwasara

    2011-01-01

    Full Text Available Background: Glycyrrhizin, obtained from Abrus precatorius (Indian liquorice, is a phytoconstituent of importance for pharmaceutical and food industries. Materials and Methods: High producing and fast growing cell lines of A. precatorius were developed by transformation with Agrobacterium tumefaciens for glycyrrhizin production. Its maximum transformation efficiency of 85% was obtained by infecting leaves with A. tumefaciens MTCC-431 supplemented with 50 μM acetosyringone. Thorough culture growth kinetics with sugar consumption profiles was established. Results: A twofold increase in glycyrrhizin productivity was obtained in transformed A. precatorius cell suspension cultures over the untransformed cultures. The fungal elicitors prepared from Aspergillus niger and Rhizopus stolonifer were tested at different concentrations to enhance glycyrrhizin production in transformed cell suspension cultures of A. precatorius. Maximum enhancement of 4.9- and 3.8-fold in glycyrrhizin contents, were obtained with A. niger (7.5% v/v and R. stolonifer (5.0% v/v, respectively, on the 5th day after elicitor treatment. Conclusion: This study indicates the prospective of the amalgamation of elicitation methodology with transformed cell cultures for the large-scale production of glycyrrhizin.

  8. Highly efficient transformation of intact yeast-like conidium cells of Tremella fuciformin by electroporation

    Institute of Scientific and Technical Information of China (English)

    GUO LiQiong; LIU Yong; ZHAO ShuXian; LIU ErXian; LIU JunFang

    2008-01-01

    Tremella fuciformis is one of higher basidiomycetes. Its basidiospore can reproduce yeast-like conidia, also called the blastospore by budding. The yeast-like conidia of T. Fuciformis is monokaryotic and easy to culture by submerged fermentation similar to yeast. So it is a good recipient cell for exogenous gone expression. In this study, two expression vectors pGIg-gfp containing gpd-GI promoter and gfp gone and pGIg-hph containing gpd-GI promoter and hph gone were constructed. The lowest sensitive concentration of hygromycin for the blastospore was determined on three types of media. Our ex-perimenta showed that the lowest sensitive concentration of hygromycin for the blastospore was 5 μg/mL on MA medium. The intact blastospores were transformed with the expression vector pGIg-hph by electroporation. The putative transformants were obtained by the MA selective medium. Experi-mental results showed that the most effective parameters for the electroporation of intact blastospores were obtained by using STM buffer, 1.0×108 cells/mL of blastospores, 200 μL in transformation volume, 6 μg plasmid, 2.0 kV/cm of electric pulse voltage, stillness culturing on MB liquid medium for 48 h after electroporation. In these transformation conditions, the efficiency reached 277 colonies/μg DNA. With the optimal parameters. The putative co-transformants were obtained by the MA selective medium. Eight randomly selected colonies from the vast putative co-transformants were analyzed by PCR de-tection and Southern blotting. The experiments showed that the gfp was integrated into the genomes of three transformants. The co-transformation efficiency was 37.5%. Green fluorescence was observed under laser scanning confocal microscope in these gfp positive transformants. This indicates that the exogenous gfp can be expressed effectively in the yeast-like conidia of T. Fuciformis.

  9. Rearrangements of chicken immunoglobulin genes in lymphoid cells transformed by the avian retroviral oncogene v-rel.

    Science.gov (United States)

    Chen, L; Lim, M Y; Bose, H; Bishop, J M

    1988-01-01

    The retroviral oncogene v-rel transforms poorly characterized lymphoid cells. We have explored the nature of these cells by analyzing the configuration and expression of immunoglobulin genes in chicken hemopoietic cells transformed by v-rel. None of the transformed cells expressed their immunoglobulin genes. The cells fell into three classes: class I cells have their immunoglobulin genes potentially in an embryonic configuration; class II and class III cells have lost one copy of the lambda light chain locus and have one copy of the heavy chain locus rearranged into a configuration that differs from what is found in mature B cells. In class II cells, the other heavy chain locus may be in embryonic configuration, whereas it is deleted in class III cells. The first of these classes may represent the earliest stage of the lymphoid lineage yet encountered among virus-transformed cells, whereas the second and third classes represent an apparently anomalous rearrangement whose origin remains unknown.

  10. Transformation from non-small-cell lung cancer to small-cell lung cancer: molecular drivers and cells of origin.

    Science.gov (United States)

    Oser, Matthew G; Niederst, Matthew J; Sequist, Lecia V; Engelman, Jeffrey A

    2015-04-01

    Lung cancer is the most common cause of cancer deaths worldwide. The two broad histological subtypes of lung cancer are small-cell lung cancer (SCLC), which is the cause of 15% of cases, and non-small-cell lung cancer (NSCLC), which accounts for 85% of cases and includes adenocarcinoma, squamous-cell carcinoma, and large-cell carcinoma. Although NSCLC and SCLC are commonly thought to be different diseases owing to their distinct biology and genomic abnormalities, the idea that these malignant disorders might share common cells of origin has been gaining support. This idea has been supported by the unexpected findings that a subset of NSCLCs with mutated EGFR return as SCLC when resistance to EGFR tyrosine kinase inhibitors develops. Additionally, other case reports have described the coexistence of NSCLC and SCLC, further challenging the commonly accepted view of their distinct lineages. Here, we summarise the published clinical observations and biology underlying tumours with combined SCLC and NSCLC histology and cancers that transform from adenocarcinoma to SCLC. We also discuss pre-clinical studies pointing to common potential cells of origin, and speculate how the distinct paths of differentiation are determined by the genomics of each disease.

  11. Relationship between transformation of human embryo lung cell and DNA strand break induced by γ-irradiation

    International Nuclear Information System (INIS)

    γ-irradiation effects on transformation and DNA strand break of human embryo lung cell were studied by means of cell and molecular biology. The cell transformation appeared at 20 th passage post 0.25∼5.0 Gy γ-irradiation. The transformation was relative to doses and post-time of irradiation. DNA strand break was detected by NTA (nick translation assay). The result indicated DNA strand break was arisen from γ ray with different doses. DNA strand break also was relative to radiation doses as cell transformation. Correlation between DNA strand break and cell transformation was analysed. The analysis indicated that effect of cell transformation enhanced with increase of DNA strand break. It was suggested that carcinogenesis by radiation is closely relative to DNA damage

  12. In vitro cytocidal effect of lytic peptides on several transformed mammalian cell lines.

    Science.gov (United States)

    Jaynes, J M; Julian, G R; Jeffers, G W; White, K L; Enright, F M

    1989-01-01

    Several types of transformed mammalian cells, derived from established cell lines, were found to be lysed in vitro by three novel lytic peptides (SB-37, SB-37*, and Shiva-1). This is in contrast with the behavior of normal cells, where the observed lytic activity of the peptides is greatly reduced. Based on experiments utilizing compounds which disrupt the cytoskeleton (colchicine and cytochalasin-D), it is surmised that alterations in the cytoskeleton of transformed cells increase their sensitivity to the cytolytic activity exerted by the peptides, primarily by causing a loss of osmotic integrity. Thus, a stable and regenerative cytoskeletal system, as that possessed by normal cells, would seem requisite to withstanding the lytic effects of the peptides.

  13. Relative efficiencies of three ultraviolet radiation wavelengths for cell killing and transformation in mouse cells in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Papadopoulo, D.; Muel, B.; Latarjet, R. (Institut du Radium, 75 - Paris (France). Lab. Curie)

    1983-09-01

    C3H 10 T 1/2 clone 8 mouse cells were irradiated in vitro with three U.V. wavelengths 280, 254, and 230 nm. Two effects were investigated, survival and malignant transformation, and the relative efficiences were determined for the three radiation. For transformation, these efficiences were: 280 nm: 3.9; 254 nm: 5.1; 230 nm: 2.3 (transformations produced by 5 J m/sup -2/ of U.V. for 1000 surviving cells). For cell killing the efficiencies were, in relative units, 34, 100, and 50 respectively. These efficiencies are in agreement with the hypothesis that the main chromophore for both effects is the nucleic acid, and not the protein moiety of the genome. This conclusion agrees with that previously reached by other investigators, but our present results obtained with the short wave-length 230 nm provide an especially strong new argument.

  14. Relative efficiencies of three ultraviolet radiation wavelengths for cell killing and transformation in mouse cells in vitro.

    Science.gov (United States)

    Papadopoulo, D; Muel, B; Latarjet, R

    1983-09-01

    C3H 10 T 1/2 clone 8 mouse cells were irradiated in vitro with three U.V. wavelengths 280, 254, and 230 nm. Two effects were investigated, survival and malignant transformation, and the relative efficiencies were determined for the three radiations. For transformation, these efficiencies were: 280nm:3.9; 254nm:5.1; 230nm:2.3 (transformations produced by 5 Jm-2 of U.V. for 1000 surviving cells). For cell killing the efficiencies were, in relative units, 34, 100, and 50 respectively. These efficiencies are in agreement with the hypothesis that the main chromophore for both effects is the nucleic acid, and not the protein moiety of the genome. This conclusion agrees with that previously reached by other investigators, but our present results obtained with the short wave-length 230 nm provide an especially strong new argument.

  15. Upregulated expression of Ezrin and invasive phenotype in malignantly transformed esophageal epithelial cells

    Institute of Scientific and Technical Information of China (English)

    Zhong-Ying Shen; Li-Yan Xu; Ming-Hua Chen; En-Min Li; Jin-Tao Li; Xian-Ying Wu; Yi Zeng

    2003-01-01

    AIM: To investigate the correlation between ezrin expression and invasive phenotype formation in malignantly transformed esophageal epithelial cells. METHODS: The experimental cell line employed in the present study was originated form the progressive induction of a human embryonic esophageal epithelial cell line (SHEE)by the E6E7 genes of human papillomavirus (HPV) type 18.The cells at the 35th passage after induction called SHEEIMM were in a state of immortalized phase and used as the control,while that of the 85th passage denominated as SHEEMT represented the status of cells that were malignantly transformed. The expression changes of ezrin and its mRNA in both cell passages were respectively analyzed by RT-PCR and Western blot. Invasive phenotype was assessed in vivo by inoculating these cells into the severe combined immunodeficient (SCID) mice via subcutaneous and intraperitoneal injection, and in vitro by inoculating them on the surface of the amnion membranes, which then was determined by light microscopy and scanning electron microscopy. RESULTS: Upregulated expression of ezrin protein and its mRNA was observed in SHEEMT compared with that in SHEEIMM cells. The SHEEMT cells inoculated in SCID mice were observed forming tumor masses in both visceral organs and soft tissues in a period of 40 days with a special propensity to invading mesentery and pancreas, but did not exhibit hepatic metastases. Pathologically, these tumor cells harboring larger nucleus, nucleolus and less cytoplasm could infiltrate and destroy adjacent tissues. In the in vitro study,the inoculated SHEEMT cells could grow in cluster on the amniotic epithelial surface and intrude into the amniotic stroma. In contrast, unrestricted growth and invasiveness were not found in SHEEIMM cells in both in vivo and in vitroexperiment. CONCLUSION: The upregulated ezrin expression is one of the important factors that are possibly associated with the invasive phenotype formation in malignantly

  16. Yeast Actin-Related Protein ARP6 Negatively Regulates Agrobacterium-Mediated Transformation of Yeast Cell.

    Science.gov (United States)

    Luo, Yumei; Chen, Zikai; Zhu, Detu; Tu, Haitao; Pan, Shen Quan

    2015-01-01

    The yeasts, including Saccharomyces cerevisiae and Pichia pastoris, are single-cell eukaryotic organisms that can serve as models for human genetic diseases and hosts for large scale production of recombinant proteins in current biopharmaceutical industry. Thus, efficient genetic engineering tools for yeasts are of great research and economic values. Agrobacterium tumefaciens-mediated transformation (AMT) can transfer T-DNA into yeast cells as a method for genetic engineering. However, how the T-DNA is transferred into the yeast cells is not well established yet. Here our genetic screening of yeast knockout mutants identified a yeast actin-related protein ARP6 as a negative regulator of AMT. ARP6 is a critical member of the SWR1 chromatin remodeling complex (SWR-C); knocking out some other components of the complex also increased the transformation efficiency, suggesting that ARP6 might regulate AMT via SWR-C. Moreover, knockout of ARP6 led to disruption of microtubule integrity, higher uptake and degradation of virulence proteins, and increased DNA stability inside the cells, all of which resulted in enhanced transformation efficiency. Our findings have identified molecular and cellular mechanisms regulating AMT and a potential target for enhancing the transformation efficiency in yeast cells.

  17. Yeast Actin-Related Protein ARP6 Negatively Regulates Agrobacterium-Mediated Transformation of Yeast Cell

    Directory of Open Access Journals (Sweden)

    Yumei Luo

    2015-01-01

    Full Text Available The yeasts, including Saccharomyces cerevisiae and Pichia pastoris, are single-cell eukaryotic organisms that can serve as models for human genetic diseases and hosts for large scale production of recombinant proteins in current biopharmaceutical industry. Thus, efficient genetic engineering tools for yeasts are of great research and economic values. Agrobacterium tumefaciens-mediated transformation (AMT can transfer T-DNA into yeast cells as a method for genetic engineering. However, how the T-DNA is transferred into the yeast cells is not well established yet. Here our genetic screening of yeast knockout mutants identified a yeast actin-related protein ARP6 as a negative regulator of AMT. ARP6 is a critical member of the SWR1 chromatin remodeling complex (SWR-C; knocking out some other components of the complex also increased the transformation efficiency, suggesting that ARP6 might regulate AMT via SWR-C. Moreover, knockout of ARP6 led to disruption of microtubule integrity, higher uptake and degradation of virulence proteins, and increased DNA stability inside the cells, all of which resulted in enhanced transformation efficiency. Our findings have identified molecular and cellular mechanisms regulating AMT and a potential target for enhancing the transformation efficiency in yeast cells.

  18. Methods for transforming and expression screening of filamentous fungal cells with a DNA library

    Energy Technology Data Exchange (ETDEWEB)

    Teter, Sarah; Lamsa, Michael; Cherry, Joel; Ward, Connie

    2015-06-02

    The present invention relates to methods for expression screening of filamentous fungal transformants, comprising: (a) isolating single colony transformants of a DNA library introduced into E. coli; (b) preparing DNA from each of the single colony E. coli transformants; (c) introducing a sample of each of the DNA preparations of step (b) into separate suspensions of protoplasts of a filamentous fungus to obtain transformants thereof, wherein each transformant contains one or more copies of an individual polynucleotide from the DNA library; (d) growing the individual filamentous fungal transformants of step (c) on selective growth medium, thereby permitting growth of the filamentous fungal transformants, while suppressing growth of untransformed filamentous fungi; and (e) measuring activity or a property of each polypeptide encoded by the individual polynucleotides. The present invention also relates to isolated polynucleotides encoding polypeptides of interest obtained by such methods, to nucleic acid constructs, expression vectors, and recombinant host cells comprising the isolated polynucleotides, and to methods of producing the polypeptides encoded by the isolated polynucleotides.

  19. Surveying selenium speciation from soil to cell - forms and transformations

    Energy Technology Data Exchange (ETDEWEB)

    Gammelgaard, Bente; Gabel-Jensen, Charlotte [University of Copenhagen, Department of Pharmaceutics and Analytical Chemistry, Faculty of Pharmaceutical Sciences, Copenhagen (Denmark); Jackson, Matthew I. [Grand Forks Human Nutrition Research Center, Agricultural Research Service, United States Department of Agriculture, Grand Forks, ND (United States)

    2011-02-15

    The aim of this review is to present and evaluate the present knowledge of which selenium species are available to the general population in the form of food and common supplements and how these species are metabolized in mammals. The overview of the selenium sources takes a horizontal approach, which encompasses identification of new metabolites in yeast and food of plant and animal origin, whereas the survey of the mammalian metabolism takes a horizontal as well as a vertical approach. The vertical approach encompasses studies on dynamic conversions of selenium compounds within cells, tissues or whole organisms. New and improved sample preparation, separation and detection methods are evaluated from an analytical chemical perspective to cover the progress in horizontal speciation, whereas the analytical methods for the vertical speciation and the interpretations of the results are evaluated from a biological angle as well. (orig.)

  20. Effects of transforming growth interacting factor on biological behaviors of gastric carcinoma cells

    Institute of Scientific and Technical Information of China (English)

    Zhong-Liang Hu; Ji-Fang Wen; De-Sheng Xiao; Hui Zhen; Chun-Yan Fu

    2005-01-01

    AIM:Transforming growth interacting factor (TGIF) is an inhibitor of both transforming growth factor β (TGF-β) and retinoid signaling pathways. Moreover, the activation of MAPK pathway can prolong its half-life. However, its role in carcinogenesis is still unknown. Thus we attempted to investigate the effect of TGIF on biologic behaviors of gastric carcinoma cells.METHODS: Gastric carcinoma cell line, SGC-7901, was stably transfected with plasmid PcDNA3.1-TGIF. Western blotting and cell immunohistochemistry screening for the highly expressing clone of TGIF were employed. The growth of transfected cells was investigated by MTT and colonyformation assays, and apoptosis was measured by flow cytometry (FCM) and transmission electron microscopy.Tumorigenicity of the transfectant cells was also analyzed.RESULTS: TGIF had no effect on the proliferation, cell cycle and apoptosis of SGC-7901 cells, but cellular organelles of cells transfected with TGIF were richer than those of vector control or parental cells. Its clones were smaller than the control ones in plate efficiency, and its tumor tissues also had no obvious necrosis compared with the vector control or parental cells. Moreover, TGIF could resist TGF-β mediated growth inhibition.CONCLUSION: TGIF may induce differentiation of stomach neoplastic cells. In addition, TGIF can counteract the growth inhibition induced by TGF-β.

  1. Butachlor, a suspected carcinogen, alters growth and transformation characteristics of mouse liver cells.

    Science.gov (United States)

    Ou, Y H; Chung, P C; Chang, Y C; Ngo, F Q; Hsu, K Y; Chen, F D

    2000-12-01

    Butachlor is a widely used herbicide in Asia and South America. Previous investigations have indicated that it is a suspected carcinogen. To understand more about the biological effects of butachlor on cultured cells and the mechanism(s) of its carcinogenicity, we studied the alteration of the growth characteristics that was induced by butachlor in normal mouse liver cells (BNL CL2). This study demonstrates that butachlor decreases the population-doubling time of BNL CL2 cells, suggesting that it stimulates cell proliferation. To support this finding, a thymidine incorporation assay was conducted and a similar result that butachlor stimulates cell proliferation was elucidated. In addition, we show that butachlor increases the saturation density of the BNL CL2 cells. When combined with the tumor initiator N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), butachlor transforms cells efficiently, as demonstrated by loss of contact inhibition. These findings indicate that butachlor alters the growth characteristics of BNL CL2 cells and suggest that butachlor may induce malignant transformation through stimulation of cell proliferation, alteration of cell cycle regulation, and suppression of cell density-dependent inhibition of proliferation.

  2. Toward genetic transformation of mitochondria in mammalian cells using a recoded drug-resistant selection marker

    Institute of Scientific and Technical Information of China (English)

    Young Geol Yoon; Michael Duane Koob

    2011-01-01

    Due to technical difficulties, the genetic transformation of mitochondria in mammalian cells is still a challenge. In this report, we described our attempts to transform mammalian mitochondria with an engineered mitochondrial genome based on selection using a drug resistance gene. Because the standard drug-resistant neomycin phosphotransferase confers resistance to high concentrations of G418 when targeted to the mitochondria, we generated a recoded neomycin resistance gene that uses the mammalian mitochondrial genetic code to direct the synthesis of this protein in the mitochondria, but not in the nucleus (mitochondrial version). We also generated a universal version of the recoded neomycin resistance gene that allows synthesis of the drug-resistant proteins both in the mitochondria and nucleus. When we transfected these recoded neomycin resistance genes that were incorporated into the mouse mitochondrial genome clones into mouse tissue culture cells by electroporation, no DNA constructs were delivered into the mitochondria. We found that the universal version of the recoded neomycin resistance gene was expressed in the nucleus and thus conferred drug resistance to G418 selection, while the synthetic mitochondrial version of the gene produced no background drug-resistant cells from nuclear transformation. These recoded synthetic drug-resistant genes could be a useful tool for selecting mitochondrial genetic transformants as a precise technology for mitochondrial transformation is developed.

  3. Identification of a region of simian virus 40 large T antigen required for cell transformation.

    OpenAIRE

    Chen, S.; Paucha, E

    1990-01-01

    A series of replication-competent simian virus 40 (SV40) large T antigens with point and deletion mutations in the amino acid sequence between residues 105 and 115 were examined for the ability to immortalize primary cultures of mouse and rat cells. The results show that certain mutants, including one that deletes the entire region, are able to immortalize. However, consistent with previous data, the immortalized cells are not fully transformed, as judged by doubling time, sensitivity to conc...

  4. [Key molecular mechanisms associated with cell malignant transformation in acute myeloid leukemia].

    Science.gov (United States)

    Orlova, N N; Lebedev, T D; Spirin, P V; Prassolov, V S

    2016-01-01

    Cancer, along with cardiovascular disorders, is one of the most important problems of healthcare. Pathologies of the hematopoietic system are the most prevalent in patients under 30 years of age, including acute myeloid leukemia (AML), which is widespread and difficult to treat. The review considers the mechanisms that play a significant role in AML cell malignant transformation and shows the contributions of certain genes to both remission and resistance of AML cells to various treatments.

  5. Molecular Mechanisms of Malignant Transformation by Low Dose Cadmium in Normal Human Bronchial Epithelial Cells.

    Directory of Open Access Journals (Sweden)

    Laura Cartularo

    Full Text Available Cadmium is a carcinogenic metal, the mechanisms of which are not fully understood. In this study, human bronchial epithelial cells were transformed with sub-toxic doses of cadmium (0.01, 0.05, and 0.1 μM and transformed clones were characterized for gene expression changes using RNA-seq, as well as other molecular measurements. 440 genes were upregulated and 47 genes were downregulated in cadmium clones relative to control clones over 1.25-fold. Upregulated genes were associated mostly with gene ontology terms related to embryonic development, immune response, and cell movement, while downregulated genes were associated with RNA metabolism and regulation of transcription. Several embryonic genes were upregulated, including the transcription regulator SATB2. SATB2 is critical for normal skeletal development and has roles in gene expression regulation and chromatin remodeling. Small hairpin RNA knockdown of SATB2 significantly inhibited growth in soft agar, indicating its potential as a driver of metal-induced carcinogenesis. An increase in oxidative stress and autophagy was observed in cadmium clones. In addition, the DNA repair protein O6-methylguanine-DNA-methyltransferase was depleted by transformation with cadmium. MGMT loss caused significant decrease in cell viability after treatment with the alkylating agent temozolomide, demonstrating diminished capacity to repair such damage. Results reveal various mechanisms of cadmium-induced malignant transformation in BEAS-2B cells including upregulation of SATB2, downregulation of MGMT, and increased oxidative stress.

  6. Complex forms of mitochondrial DNA in human B cells transformed by Epstein-Barr virus (EBV)

    DEFF Research Database (Denmark)

    Christiansen, Gunna; Christiansen, C; Zeuthen, J

    1983-01-01

    Human lymphocytes and lymphoid cell lines were analyzed for the presence of complex forms of mitochondrial DNA (mtDNA) by electron microscopy. A high frequency (9%-14.5%) of catenated dimers, circular dimers, or oligomers were found in samples from Epstein-Barr-virus-(EBV) transformed...

  7. Islet amyloid polypeptide and insulin expression are controlled differently in primary and transformed islet cells

    DEFF Research Database (Denmark)

    Madsen, O D; Michelsen, Bo Thomas; Westermark, P;

    1991-01-01

    the tissue specificity of expressions of IAPP and insulin are controlled differently, and that coexpression of IAPP with hormones different from insulin may be a marker for pluripotent transformed rat islet cell clones, which are able to activate insulin gene transcription during passage in vivo....

  8. Constitutive phosphorylation of eps8 in tumor cell lines: relevance to malignant transformation

    DEFF Research Database (Denmark)

    Matoskova, B; Wong, W T; Salcini, A E;

    1995-01-01

    eps8, a recently identified tyrosine kinase substrate, has been shown to augment epidermal growth factor (EGF) responsiveness, implicating it in EGF receptor (EGFR)-mediated mitogenic signaling. We investigated the status of eps8 phosphorylation in normal and transformed cells and the role of eps...

  9. Insertional transformation of hematopoietic cells by self-inactivating lentiviral and gammaretroviral vectors.

    Science.gov (United States)

    Modlich, Ute; Navarro, Susana; Zychlinski, Daniela; Maetzig, Tobias; Knoess, Sabine; Brugman, Martijn H; Schambach, Axel; Charrier, Sabine; Galy, Anne; Thrasher, Adrian J; Bueren, Juan; Baum, Christopher

    2009-11-01

    Gene transfer vectors may cause clonal imbalance and even malignant cell transformation by insertional upregulation of proto-oncogenes. Lentiviral vectors (LV) with their preferred integration in transcribed genes are considered less genotoxic than gammaretroviral vectors (GV) with their preference for integration next to transcriptional start sites and regulatory gene regions. Using a sensitive cell culture assay and a series of self-inactivating (SIN) vectors, we found that the lentiviral insertion pattern was approximately threefold less likely than the gammaretroviral to trigger transformation of primary hematopoietic cells. However, lentivirally induced mutants also showed robust replating, in line with the selection for common insertion sites (CIS) in the first intron of the Evi1 proto-oncogene. This potent proto-oncogene thus represents a CIS for both GV and LV, despite major differences in their integration mechanisms. Altering the vectors' enhancer-promoter elements had a greater effect on safety than the retroviral insertion pattern. Clinical grade LV expressing the Wiskott-Aldrich syndrome (WAS) protein under control of its own promoter had no transforming potential. Mechanistic studies support the conclusion that enhancer-mediated gene activation is the major cause for insertional transformation of hematopoietic cells, opening rational strategies for risk prevention.

  10. β-Catenin Does Not Confer Tumorigenicity When Introduced into Partially Transformed Human Mesenchymal Stem Cells

    Directory of Open Access Journals (Sweden)

    Sajida Piperdi

    2012-01-01

    Full Text Available Although osteosarcoma is the most common primary malignant bone tumor in children and adolescents, its cell of origin and the genetic alterations are unclear. Previous studies have shown that serially introducing hTERT, SV40 large TAg, and H-Ras transforms human mesenchymal stem cells into two distinct sarcomas cell populations, but they do not form osteoid. In this study, β-catenin was introduced into mesenchymal stem cells already containing hTERT and SV40 large TAg to analyze if this resulted in a model which more closely recapitulated osteosarcoma. Results. Regardless of the level of induced β-catenin expression in the stable transfectants, there were no marked differences induced in their phenotype or invasion and migration capacity. Perhaps more importantly, none of them formed tumors when injected into immunocompromised mice. Moreover, the resulting transformed cells could be induced to osteogenic and chondrogenic differentiation but not to adipogenic differentiation. Conclusions. β-catenin, although fostering osteogenic differentiation, does not induce the malignant features and tumorigenicity conveyed by oncogenic H-RAS when introduced into partly transformed mesenchymal stem cells. This may have implications for the role of β-catenin in osteosarcoma pathogenesis. It also may suggest that adipogenesis is an earlier branch point than osteogenesis and chondrogenesis in normal mesenchymal differentiation.

  11. Increased Association of Dynamin Ⅱ with Myosin Ⅱ in Ras Transformed NIH3T3 Cells

    Institute of Scientific and Technical Information of China (English)

    Soon-Jeong JEONG; Su-Gwan KIM; Jiyun YOO; Mi-Young HAN; Joo-Cheol PARK; Heung-Joong KIM; Seong Soo KANG; Baik-Dong CHOI; Moon-Jin JEONG

    2006-01-01

    Dynamin has been implicated in the formation of nascent vesicles through both endocytic and secretory pathways. However, dynamin has recently been implicated in altering the cell membrane shape during cell migration associated with cytoskeleton-related proteins. Myosin Ⅱ has been implicated in maintaining cell morphology and in cellular movement. Therefore, reciprocal immunoprecipitation was carried out to identify the potential relationship between dynamin Ⅱ and myosin Ⅱ. The dynamin Ⅱ expression level was higher when co-expressed with myosin Ⅱ in Ras transformed NIH3T3 cells than in normal NIH3T3 cells.Confocal microscopy also confirmed the interaction between these two proteins. Interestingly, exposing the NIH3T3 cells to platelet-derived growth factor altered the interaction and localization of these two proteins.The platelet-derived growth factor treatment induced lamellipodia and cell migration, and dynamin Ⅱ interacted with myosin Ⅱ. Grb2, a 24 kDa adaptor protein and an essential element of the Ras signaling pathway,was found to be associated with dynamin Ⅱ and myosin Ⅱ gene expression in the Ras transformed NIH3T3 cells. These results suggest that dynamin Ⅱ acts as an intermediate messenger in the Ras signal transduction pathway leading to membrane ruffling and cell migration.

  12. Organotypic culture in three dimensions prevents radiation-induced transformation in human lung epithelial cells

    Science.gov (United States)

    El-Ashmawy, Mariam; Coquelin, Melissa; Luitel, Krishna; Batten, Kimberly; Shay, Jerry W.

    2016-08-01

    The effects of radiation in two-dimensional (2D) cell culture conditions may not recapitulate tissue responses as modeled in three-dimensional (3D) organotypic culture. In this study, we determined if the frequency of radiation-induced transformation and cancer progression differed in 3D compared to 2D culture. Telomerase immortalized human bronchial epithelial cells (HBECs) with shTP53 and mutant KRas expression were exposed to various types of radiation (gamma, +H, 56Fe) in either 2D or 3D culture. After irradiation, 3D structures were dissociated and passaged as a monolayer followed by measurement of transformation, cell growth and expression analysis. Cells irradiated in 3D produced significantly fewer and smaller colonies in soft agar than their 2D-irradiated counterparts (gamma P = 0.0004 +H P = 0.049 56Fe P culture conditions did not affect cell killing, the ability of cells to survive in a colony formation assay, and proliferation rates after radiation—implying there was no selection against cells in or dissociated from 3D conditions. However, DNA damage repair and apoptosis markers were increased in 2D cells compared to 3D cells after radiation. Ideally, expanding the utility of 3D culture will allow for a better understanding of the biological consequences of radiation exposure.

  13. Mos1 transposon-based transformation of fish cell lines using baculoviral vectors

    Energy Technology Data Exchange (ETDEWEB)

    Yokoo, Masako [Laboratory of Applied Molecular Entomology, Division of Applied Bioscience, Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589 (Japan); Fujita, Ryosuke [Laboratory of Applied Molecular Entomology, Division of Applied Bioscience, Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589 (Japan); Innate Immunity Laboratory, Graduate School of Life Science and Creative Research Institution, Hokkaido University, Sapporo 001-0021 (Japan); Nakajima, Yumiko [Functional Genomics Group, COMB, Tropical Biosphere Research Center, University of the Ryukyus, Okinawa 903-0213 (Japan); Yoshimizu, Mamoru; Kasai, Hisae [Faculty of Fisheries Sciences, Hokkaido University, Hakodate 041-8611 (Japan); Asano, Shin-ichiro [Laboratory of Applied Molecular Entomology, Division of Applied Bioscience, Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589 (Japan); Bando, Hisanori, E-mail: hban@abs.agr.hokudai.ac.jp [Laboratory of Applied Molecular Entomology, Division of Applied Bioscience, Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589 (Japan)

    2013-09-13

    Highlights: •The baculovirus vector infiltrates the cells of economic important fishes. •Drosophila Mos1 transposase expressed in fish cells maintains its ability to localize to the nucleus. •The baculoviral vector carrying Mos1 is a useful tool to stably transform fish cells. -- Abstract: Drosophila Mos1 belongs to the mariner family of transposons, which are one of the most ubiquitous transposons among eukaryotes. We first determined nuclear transportation of the Drosophila Mos1-EGFP fusion protein in fish cell lines because it is required for a function of transposons. We next constructed recombinant baculoviral vectors harboring the Drosophila Mos1 transposon or marker genes located between Mos1 inverted repeats. The infectivity of the recombinant virus to fish cells was assessed by monitoring the expression of a fluorescent protein encoded in the viral genome. We detected transgene expression in CHSE-214, HINAE, and EPC cells, but not in GF or RTG-2 cells. In the co-infection assay of the Mos1-expressing virus and reporter gene-expressing virus, we successfully transformed CHSE-214 and HINAE cells. These results suggest that the combination of a baculovirus and Mos1 transposable element may be a tool for transgenesis in fish cells.

  14. Naturally occurring variants of human Α9 nicotinic receptor differentially affect bronchial cell proliferation and transformation.

    Directory of Open Access Journals (Sweden)

    Anna Chikova

    Full Text Available Isolation of polyadenilated mRNA from human immortalized bronchial epithelial cell line BEP2D revealed the presence of multiple isoforms of RNA coded by the CHRNA9 gene for α9 nicotinic acetylcholine receptor (nAChR. BEP2D cells were homozygous for the rs10009228 polymorphism encoding for N442S amino acid substitution, and also contained mRNA coding for several truncated isoforms of α9 protein. To elucidate the biologic significance of the naturally occurring variants of α9 nAChR, we compared the biologic effects of overexpression of full-length α9 N442 and S442 proteins, and the truncated α9 variant occurring due to a loss of the exon 4 sequence that causes frame shift and early termination of the translation. These as well as control vector were overexpressed in the BEP2D cells that were used in the assays of proliferation rate, spontaneous vs. tobacco nitrosamine 4-(methylnitrosamino-1-(3-pyridyl-1-butanone (NNK-induced cellular transformation, and tumorigenicity in cell culture and mice. Overexpression of the S442 variant significantly increased cellular proliferation, and spontaneous and NNK-induced transformation. The N442 variant significantly decreased cellular transformation, without affecting proliferation rate. Overexpression of the truncated α9 significantly decreased proliferation and suppressed cellular transformation. These results suggested that α9 nAChR plays important roles in regulation of bronchial cell growth by endogenous acetylcholine and exogenous nicotine, and susceptibility to NNK-induced carcinogenic transformation. The biologic activities of α9 nAChR may be regulated at the splicing level, and genetic polymorphisms in CHRNA9 affecting protein levels, amino acid sequence and RNA splicing may influence the risk for lung cancer.

  15. Rat Testicular Germ Cells and Sertoli Cells Release Different Types of Bioactive Transforming Growth Factor-B in vitro

    NARCIS (Netherlands)

    Haagmans, B.L.; Hoogerbrugge, J.W.; Themmen, A.P.N.; Teerds, K.J.

    2003-01-01

    Several in vivo studies have reported the presence of immunoreactive transforming growth factor-ß's (TGF-ß's) in testicular cells at defined stages of their differentiation. The most pronounced changes in TGF-ß1 and TGF-ß2 immunoreactivity occurred during spermatogenesis. In the present study we hav

  16. Rat testicular germ cells and sertoli cells release different types of bioactive transforming growth factor beta in vitro

    NARCIS (Netherlands)

    B.L. Haagmans (Bart); J.W. Hoogerbrugge (Jos); A.P.N. Themmen (Axel); K.J. Teerds (Katja)

    2003-01-01

    textabstractSeveral in vivo studies have reported the presence of immunoreactive transforming growth factor-β's (TGF-β's) in testicular cells at defined stages of their differentiation. The most pronounced changes in TGF-β1 and TGF-β2 immunoreactivity occurred during spermatogenesis. In the present

  17. Karyotyping of Chromosomes in Human Bronchial Epithelial Cells Transformed by High Energy Fe Ions

    Science.gov (United States)

    Yeshitla, Samrawit; Zhang, Ye; Park, Seongmi; Story, Michael D.; Wilson, Bobby; Wu, Honglu

    2015-01-01

    Lung cancer induced from exposures to space radiation is one of the most significant health risks for long-term space travels. Evidences show that low- and high- Linear energy transfer (LET)-induced transformation of normal human bronchial epithelial cells (HBEC) that are immortalized through the expression of Cdk4 and hTERT. The cells were exposed to gamma rays and high-energy Fe ions for the selection of transformed clones. Transformed HBEC are identified and analyzed chromosome aberrations (i.e. genomic instability) using the multi-color fluorescent in situ hybridization (mFISH), as well as the multi-banding in situ hybridization (mBAND) techniques. Our results show chromosomal translocations between different chromosomes and several of the breaks occurred in the q-arm of chromosome 3. We also identified copy number variations between the transformed and the parental HBEC regardless of the exposure conditions. We observed chromosomal aberrations in the lowand high-LET radiation-induced transformed clones and they are imperfectly different from clones obtain in spontaneous soft agar growth.

  18. Menin expression is regulated by transforming growth factor beta signaling in leukemia cells

    Institute of Scientific and Technical Information of China (English)

    ZHANG Hui; LIU Zu-guo; HUA Xian-xin

    2011-01-01

    Background Menin is a ubiquitously expressed protein encoded by the multiple endocrine neoplasia type 1 (MEN1)gene. Besides its importance in endocrine organs, menin has been shown to interact with the mixed lineage leukemia (MLL) protein, a histone H3 lysine 4 methyltransferase, and plays a critical role in hematopoiesis and leukemogenesis.Previous studies have shown that menin promotes transforming growth factor beta (TGF-β) signaling in endocrine cells.However, little is known regarding the impact of TGF-β pathway on menin in hematopoietic system. Here, with leukemia cell lines generated from conditional MEN1 or TGF-p receptor (TβRII) knockout mouse models, we investigated the possible cross-talk of these two pathways in leukemia cells.Methods MEN1 or TβRII conditional knockout mice were bred and the bone marrow cells were transduced with retroviruses expressing oncogeneic MLL-AF9 (a mixed lineage leukemia fusion protein) to generate two leukemia cell lines. Cell proliferation assays were performed to investigate the effect of TGF-β treatment on MLL-AF9 transformed leukemia cells with/without MEN1 or TβRII excision. Menin protein was detected with Western blotting and mRNA levels of cell proliferation-related genes Cyclin A2 and Cyclin E2 were examined with real-time RT-PCR for each treated sample.In vivo effect of TGF-p signal on menin expression was also investigated in mouse liver tissue after TβRII excision.Results TGF-β not only inhibited the proliferation of wild type MLL-AF9 transformed mouse bone marrow cells, but also up-regulated menin expression in these cells. Moreover, TGF-P failed to further inhibit the proliferation of Men1-null cells as compared to Men1-expressing control cells. Furthermore, excision of TβRII, a vital component in TGF-β signaling pathway, down-regulated menin expression in MLL-AF9 transformed mouse bone marrow cells. In vivo data also confirmed that menin expression was decreased in liver samples of conditional T

  19. DUAL ION EXPOSURE VS. SPLIT-DOSE EXPOSURES IN HUMAN CELL NEOPLASTIC TRANSFORMATION.

    Energy Technology Data Exchange (ETDEWEB)

    BENNETT, P.V.; CUTTER, N.C.; SUTHERLAND, B.M.

    2006-06-05

    Since radiation fields of space contain many-fold more protons than high atomic number, high energy (HZE) particles, cells in astronaut crews will experience on average several proton hits before an HZE hit. Thus radiation regimes of proton exposure before HZE particle exposure simulate space radiation exposure, and measurement of the frequency of neoplastic transformation of human primary cells to anchorage-independent growth simulates in initial step in cancer induction. Previously our group found that exposure to 20 cGy 1 GeV/n protons followed within about 1 hr by a HZE ion (20 cGy 1 GeV/n Fe or Ti ions) hit gave about a 3-fold increase in transformation frequency ([1]). To provide insight into the H-HZE induced increased transformation frequencies, we asked if split doses of the same ion gave similar increased transformation frequencies. However, the data show that the split dose of 20 cGy plus 20 cGy of either H or HZE ions gave about the same effect as the 40 cGy uninterrupted dose, quite different from the effect of the mixed ion H + HZE irradiation. We also asked if lower proton doses than 20 cGy followed 15 minutes later by 20 cGy of HZE ions gave greater than additive transformation frequencies. Substantial increases in transformation levels were observed for all proton doses tested, including 1 cGy. These results point to the signal importance of protons in affecting the effect of space radiation on human cells.

  20. Highly efficient transformation of intact yeast-like conidium cells of Tremella fuciformis by electroporation

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Tremella fuciformis is one of higher basidiomycetes. Its basidiospore can reproduce yeast-like conidia, also called the blastospore by budding. The yeast-like conidia of T. fuciformis is monokaryotic and easy to culture by submerged fermentation similar to yeast. So it is a good recipient cell for exogenous gene expression. In this study, two expression vectors pGlg-gfp containing gpd-Gl promoter and gfp gene and pGlg-hph containing gpd-Gl promoter and hph gene were constructed. The lowest sensitive concentration of hygromycin for the blastospore was determined on three types of media. Our ex- periments showed that the lowest sensitive concentration of hygromycin for the blastospore was 5 μg/mL on MA medium. The intact blastospores were transformed with the expression vector pGlg-hph by electroporation. The putative transformants were obtained by the MA selective medium. Experi- mental results showed that the most effective parameters for the electroporation of intact blastospores were obtained by using STM buffer, 1.0×108 cells/mL of blastospores, 200 μL in transformation volume, 6 μg plasmid, 2.0 kV/cm of electric pulse voltage, stillness culturing on MB liquid medium for 48 h after electroporation. In these transformation conditions, the efficiency reached 277 colonies/μg DNA. Co-transformation of plasmid pGlg-gfp and pGlg-hph with ratio of 1:1 was performed by electroporation with the optimal parameters. The putative co-transformants were obtained by the MA selective medium. Eight randomly selected colonies from the vast putative co-transformants were analyzed by PCR de- tection and Southern blotting. The experiments showed that the gfp was integrated into the genomes of three transformants. The co-transformation efficiency was 37.5%. Green fluorescence was observed under laser scanning confocal microscope in these gfp positive transformants. This indicates that the exogenous gfp can be expressed effectively in the yeast-like conidia of T. fuciformis.

  1. A novel system for Agrobacterium-mediated transformation of wheat( Triticum aestivum L.) cells

    Institute of Scientific and Technical Information of China (English)

    XUYAO; BAOJIANLI; JINGFENJIA

    1993-01-01

    A new approach for transforming the cultured cells of wheat (Triticum aestivum L.cv.Ganmai 8)was developed vsing Agrobacterium tumefaciens. The features of the optimum procedure were:(a)both combined synthetic signal molecules and multiple natural extracts from susceptible plants were used to pretreat the primary vigorous Agrobacterium(PVA)cells for approximately 16h:(b)the gyratory magnetic field condition was used during cocultivation;(c)the cocultivating period and selecting condition were modified;(d)the recipient cells were at exuberant metabolism and active division while infected with Agrobacterium.Both neomycin phosphotransferase and nopaline synthase assays demonstrated the expression of NPT Ⅱ and NOS genes.located on the T-DNA segment of chimaeric plasmid pGV3850::1103neo.in transformed wheat cell colonies by adopting the techniques of dot blot ndPAGE or high voltage paper electrophoresis,Integration of the foreign genes into wheat genome was confirmed by Southerm blot hybridization.Moreover.a relatively rational method was described for the estimation of transformation frequencies from cultured cell levels.

  2. Pre-micro RNA signatures delineate stages of endothelial cell transformation in Kaposi sarcoma.

    Directory of Open Access Journals (Sweden)

    Andrea J O'Hara

    2009-04-01

    Full Text Available MicroRNAs (miRNA have emerged as key regulators of cell lineage differentiation and cancer. We used precursor miRNA profiling by a novel real-time QPCR method (i to define progressive stages of endothelial cell transformation cumulating in Kaposi sarcoma (KS and (ii to identify specific miRNAs that serve as biomarkers for tumor progression. We were able to compare primary patient biopsies to well-established culture and mouse tumor models. Loss of mir-221 and gain of mir-15 expression demarked the transition from merely immortalized to fully tumorigenic endothelial cells. Mir-140 and Kaposi sarcoma-associated herpesvirus viral miRNAs increased linearly with the degree of transformation. Mir-24 emerged as a biomarker specific for KS.

  3. Ethylene bisdithiocarbamate pesticides cause cytotoxicity in transformed and normal human colon cells.

    Science.gov (United States)

    Hoffman, Lisa; Hardej, Diane

    2012-09-01

    The effects of the fungicides Maneb, Mancozeb, and Zineb were investigated in transformed colon cells, HT-29, Caco2 and non-transformed cells, CCD-18Co. Significant decreases in viability were observed with Maneb and Mancozeb in HT-29 and CCD-18Co (80-260μM), and Caco2 cells (40-180μM). No significant decreases in viability were observed in all cell types up to 800μM with Zineb. MnCl(2) and ZnCl(2) exposure produced no loss of viability in all cell types up to 400μM. Light microscopy confirmed viability analysis. Lipid peroxidation was observed with Maneb and Mancozeb in cell types tested (60-200μM). Caspase 3/7, 8, and 9 activities were observed with Maneb and Mancozeb in cell types tested (40-200μM). Maneb and Mancozeb treated HT-29 and Caco2 cells demonstrated increases in manganese and zinc concentrations (20-200μM). The lack of toxicity observed with Zineb, MnCl(2), and ZnCl(2) suggests that both the metal moiety and the organic portion of these fungicides together contribute to toxicity. PMID:22824503

  4. Ethylene bisdithiocarbamate pesticides cause cytotoxicity in transformed and normal human colon cells.

    Science.gov (United States)

    Hoffman, Lisa; Hardej, Diane

    2012-09-01

    The effects of the fungicides Maneb, Mancozeb, and Zineb were investigated in transformed colon cells, HT-29, Caco2 and non-transformed cells, CCD-18Co. Significant decreases in viability were observed with Maneb and Mancozeb in HT-29 and CCD-18Co (80-260μM), and Caco2 cells (40-180μM). No significant decreases in viability were observed in all cell types up to 800μM with Zineb. MnCl(2) and ZnCl(2) exposure produced no loss of viability in all cell types up to 400μM. Light microscopy confirmed viability analysis. Lipid peroxidation was observed with Maneb and Mancozeb in cell types tested (60-200μM). Caspase 3/7, 8, and 9 activities were observed with Maneb and Mancozeb in cell types tested (40-200μM). Maneb and Mancozeb treated HT-29 and Caco2 cells demonstrated increases in manganese and zinc concentrations (20-200μM). The lack of toxicity observed with Zineb, MnCl(2), and ZnCl(2) suggests that both the metal moiety and the organic portion of these fungicides together contribute to toxicity.

  5. Morphological Transformation of Plant Cells in vitro and Its Effect on Plant Growth

    Institute of Scientific and Technical Information of China (English)

    GUO Zhigang; ZENG Zhaolin; LIU Ruizhi; DENG Ying

    2005-01-01

    Enhancement of cell growth in suspension cultures is urgently needed in plant cell culture engineering. This study investigates the relationship between morphological transformation and cell growth in callus and suspension cultures of saffron cells belonging to the cell line C96 induced from Crocus sativus L. In the suspension culture, an unbalanced osmotic pressure between the intracell and extracell regions induced a large morphological transformation which affected normal division of the saffron cells. An increase in osmotic pressure caused by the addition of sucrose inhibits the vacuolation and shrinkage of cytoplasm in the cells. As the sucrose concentration increases, the total amount of accumulated biomass also increases. Besides the sucrose concentration, increased ionic strength and inoculation ratio also help restrain to a large extent the vacuolation and shrinkage of the cytoplasm in the suspended cells, which results in increased biomass. The conditions for optimal biomass are: Murashige and Skoog's (MS) medium with 40 g/L sucrose and 60% (v/v) inoculation ratio.

  6. Constitutive activation of the interleukin 2 gene in the induction of spontaneous in vitro transformation and tumorigenicity of T cells.

    OpenAIRE

    Nagarkatti, M.; Hassuneh, M; Seth, A.; Manickasundari, K; Nagarkatti, P S

    1994-01-01

    There is growing evidence to suggest that tumorigenic transformation of cells may result from aberrant regulation of autocrine growth factor production. In the current study we describe the spontaneous in vitro transformation of T-lymphocyte cell lines during routine cell culture as evidenced by autonomous growth without any requirement for stimulation or exogenous interleukin 2 (IL-2). These cells constitutively expressed the IL-2 gene and were inhibited from proliferating by addition of ant...

  7. Andrographolide Sensitizes Ras-Transformed Cells to Radiation in vitro and in vivo

    International Nuclear Information System (INIS)

    Purpose: Increasing the sensitivity of tumor cells to radiation is a major goal of radiotherapy. The present study investigated the radiosensitizing effects of andrographolide and examined the molecular mechanisms of andrographolide-mediated radiosensitization. Methods and Materials: An H-ras-transformed rat kidney epithelial (RK3E) cell line was used to measure the radiosensitizing effects of andrographolide in clonogenic assays, 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H tetrazolium bromide assays, and a xenograft tumor growth model. The mechanism of andrographolide-sensitized cell death was analyzed using annexin V staining, caspase 3 activity assays, and terminal transferase uridyl nick end labeling assays. The roles of nuclear factor kappa B (NF-κB) and Akt in andrographolide-mediated sensitization were examined using reporter assays, electrophoretic mobility shift assays, and Western blotting. Results: Concurrent andrographolide treatment (10 μM, 3 h) sensitized Ras-transformed cells to radiation in vitro (sensitizer enhancement ratio, 1.73). Andrographolide plus radiation (one dose of 300 mg/kg peritumor andrographolide and one dose of 6 Gy radiation) resulted in significant tumor growth delay (27 ± 2.5 days) compared with radiation alone (22 ± 1.5 days; p <.05). Radiation induced apoptotic markers (e.g., caspase-3, membrane reversion, DNA fragmentation), and andrographolide treatment did not promote radiation-induced apoptosis. However, the protein level of activated Akt was significantly reduced by andrographolide. NF-κB activity was elevated in irradiated Ras-transformed cells, and andrographolide treatment significantly reduced radiation-induced NF-κB activity. Conclusion: Andrographolide sensitized Ras-transformed cells to radiation both in vitro and in vivo. Andrographolide-mediated radiosensitization was associated with downregulation of Akt and NF-κB activity. These observations indicate that andrographolide is a novel radiosensitizing agent

  8. Impaired antiviral response of adenovirus-transformed cell lines supports virus replication.

    Science.gov (United States)

    Bachmann, Mandy; Breitwieser, Theresa; Lipps, Christoph; Wirth, Dagmar; Jordan, Ingo; Reichl, Udo; Frensing, Timo

    2016-02-01

    Activation of the innate immune response represents one of the most important cellular mechanisms to limit virus replication and spread in cell culture. Here, we examined the effect of adenoviral gene expression on the antiviral response in adenovirus-transformed cell lines; HEK293, HEK293SF and AGE1.HN. We demonstrate that the expression of the early region protein 1A in these cell lines impairs their ability to activate antiviral genes by the IFN pathway. This property may help in the isolation of newly emerging viruses and the propagation of interferon-sensitive virus strains.

  9. Alteration of gene expression profiles during mycoplasma-induced malignant cell transformation

    International Nuclear Information System (INIS)

    Mycoplasmas are the smallest microorganisms capable of self-replication. Our previous studies show that some mycoplasmas are able to induce malignant transformation of host mammalian cells. This malignant transformation is a multistage process with the early infection, reversible and irreversible stages, and similar to human tumor development in nature. The purpose of this study is to explore mechanisms for this malignant transformation. To better understand mechanisms for this unique process, we examined gene expression profiles of C3H cells at different stages of the mycoplasma-induced transformation using cDNA microarray technology. A total of 1185 genes involved in oncogenesis, apoptosis, cell growth, cell-cycle regulation, DNA repair, etc. were examined. Differences in the expression of these genes were compared and analyzed using the computer software AtlasImage. Among 1185 genes screened, 135 had aberrant expression at the early infection stage, 252 at the reversible stage and 184 at the irreversible stage. At the early infection stage, genes with increased expression (92 genes) were twice more than those with decreased expression (42 genes). The global gene expression at the reversible stage appeared to be more volatile than that at any other stages but still resembled the profile at the early infection stage. The expression profile at the irreversible stage shows a unique pattern of a wide range of expression levels and an increased number of expressing genes, especially the cancer-related genes. Oncogenes and tumor suppressors are a group of molecules that showed significant changes in expression during the transformation. The majority of these changes occurred in the reversible and irreversible stages. A prolonged infection by mycoplasmas lead to the expression of more cancer related genes at the irreversible stage. The results indicate that the expression profiles correspond with the phenotypic features of the cells in the mycoplasma induced

  10. Impaired telomerase activity hinders proliferation and in vitro transformation of Penaeus monodon lymphoid cells.

    Science.gov (United States)

    Jayesh, P; Vrinda, S; Priyaja, P; Philip, Rosamma; Singh, I S Bright

    2016-08-01

    Retaining terminal transferase activity of telomerase, the ribonucleoprotein enzyme which add telomeric repeats on chromosome end is thought to be required to prevent cellular ageing. Additionally, telomerase considered as a marker for cell proliferation and immortalization in eukaryotes. We examined telomerase activity in tissues and lymphoid cell culture of Penaeus monodon. Along with telomerase activity, telomere repeats and an attempt on identification of telomerase reverse transcriptase (PmTERT) were made. Telomeric repeat amplification protocol revealed that telomerase-dependent telomeric lengthening has been taking place in P. monodon and the adult tissues were retaining this capacity throughout their lifespan with the highest activity in ovary, testis and lymphoid organ. However, telomerase activity could not be detected in lymphoid cells in culture. The canonical telomeric repeats added by telomerase of lymphoid tissue extract were identified as TTAGG, but pentameric repeats GGTTA and AGGTT were also added by the telomerase. PmTERT protein sequence (partial) shared 100 % identity with the TERT sequence of Daphnia pulex, 27 % sequence identity with Purple sea urchin and 24-25 % with Zebra fish. Undetectable telomerase activity in lymphoid cell culture supports the hypothesis that the inadequate telomerase activity or gene expression may be a reason that prevents neoplastic transformation and spontaneous immortalization of the cells in vitro. Thus, it is envisaged that telomerase activation in lymphoid cells may surmount cellular ageing for in vitro transformation and cell line establishment. PMID:26084784

  11. Impaired telomerase activity hinders proliferation and in vitro transformation of Penaeus monodon lymphoid cells.

    Science.gov (United States)

    Jayesh, P; Vrinda, S; Priyaja, P; Philip, Rosamma; Singh, I S Bright

    2016-08-01

    Retaining terminal transferase activity of telomerase, the ribonucleoprotein enzyme which add telomeric repeats on chromosome end is thought to be required to prevent cellular ageing. Additionally, telomerase considered as a marker for cell proliferation and immortalization in eukaryotes. We examined telomerase activity in tissues and lymphoid cell culture of Penaeus monodon. Along with telomerase activity, telomere repeats and an attempt on identification of telomerase reverse transcriptase (PmTERT) were made. Telomeric repeat amplification protocol revealed that telomerase-dependent telomeric lengthening has been taking place in P. monodon and the adult tissues were retaining this capacity throughout their lifespan with the highest activity in ovary, testis and lymphoid organ. However, telomerase activity could not be detected in lymphoid cells in culture. The canonical telomeric repeats added by telomerase of lymphoid tissue extract were identified as TTAGG, but pentameric repeats GGTTA and AGGTT were also added by the telomerase. PmTERT protein sequence (partial) shared 100 % identity with the TERT sequence of Daphnia pulex, 27 % sequence identity with Purple sea urchin and 24-25 % with Zebra fish. Undetectable telomerase activity in lymphoid cell culture supports the hypothesis that the inadequate telomerase activity or gene expression may be a reason that prevents neoplastic transformation and spontaneous immortalization of the cells in vitro. Thus, it is envisaged that telomerase activation in lymphoid cells may surmount cellular ageing for in vitro transformation and cell line establishment.

  12. (1)H NMR studies distinguish the water soluble metabolomic profiles of untransformed and RAS-transformed cells.

    Science.gov (United States)

    Marks, Vered; Munoz, Anisleidys; Rai, Priyamvada; Walls, Jamie D

    2016-01-01

    Metabolomic profiling is an increasingly important method for identifying potential biomarkers in cancer cells with a view towards improved diagnosis and treatment. Nuclear magnetic resonance (NMR) provides a potentially noninvasive means to accurately characterize differences in the metabolomic profiles of cells. In this work, we use (1)H NMR to measure the metabolomic profiles of water soluble metabolites extracted from isogenic control and oncogenic HRAS-, KRAS-, and NRAS-transduced BEAS2B lung epithelial cells to determine the robustness of NMR metabolomic profiling in detecting differences between the transformed cells and their untransformed counterparts as well as differences among the RAS-transformed cells. Unique metabolomic signatures between control and RAS-transformed cell lines as well as among the three RAS isoform-transformed lines were found by applying principal component analysis to the NMR data. This study provides a proof of principle demonstration that NMR-based metabolomic profiling can robustly distinguish untransformed and RAS-transformed cells as well as cells transformed with different RAS oncogenic isoforms. Thus, our data may potentially provide new diagnostic signatures for RAS-transformed cells. PMID:27330862

  13. Mapping of ESE-1 subdomains required to initiate mammary epithelial cell transformation via a cytoplasmic mechanism

    Directory of Open Access Journals (Sweden)

    Tentler John J

    2011-08-01

    Full Text Available Abstract Background The ETS family transcription factor ESE-1 is often overexpressed in human breast cancer. ESE-1 initiates transformation of MCF-12A cells via a non-transcriptional, cytoplasmic process that is mediated by a unique 40-amino acid serine and aspartic acid rich (SAR subdomain, whereas, ESE-1's nuclear transcriptional property is required to maintain the transformed phenotype of MCF7, ZR-75-1 and T47D breast cancer cells. Results To map the minimal functional nuclear localization (NLS and nuclear export (NES signals, we fused in-frame putative NLS and NES motifs between GFP and the SAR domain. Using these GFP constructs as reporters of subcellular localization, we mapped a single NLS to six basic amino acids (242HGKRRR247 in the AT-hook and two CRM1-dependent NES motifs, one to the pointed domain (NES1: 102LCNCALEELRL112 and another to the DNA binding domain (DBD, (NES2: 275LWEFIRDILI284. Moreover, analysis of a putative NLS located in the DBD (316GQKKKNSN323 by a similar GFP-SAR reporter or by internal deletion of the DBD, revealed this sequence to lack NLS activity. To assess the role of NES2 in regulating ESE-1 subcellular localization and subsequent transformation potency, we site-specifically mutagenized NES2, within full-length GFP-ESE-1 and GFP-NES2-SAR reporter constructs. These studies show that site-specific mutation of NES2 completely abrogates ESE-1 transforming activity. Furthermore, we show that exclusive cytoplasmic targeting of the SAR domain is sufficient to initiate transformation, and we report that an intact SAR domain is required, since block mutagenesis reveals that an intact SAR domain is necessary to maintain its full transforming potency. Finally, using a monoclonal antibody targeting the SAR domain, we demonstrate that the SAR domain contains a region accessible for protein - protein interactions. Conclusions These data highlight that ESE-1 contains NLS and NES signals that play a critical role in

  14. Hemizygosity for Atm and Brca1 influence the balance between cell transformation and apoptosis

    Directory of Open Access Journals (Sweden)

    Zhu Jiayun

    2010-02-01

    Full Text Available Abstract Background In recent years data from both mouse models and human tumors suggest that loss of one allele of genes involved in DNA repair pathways may play a central role in genomic instability and carcinogenesis. Additionally several examples in mouse models confirmed that loss of one allele of two functionally related genes may have an additive effect on tumor development. To understand some of the mechanisms involved, we examined the role of monoallelic loss or Atm and Brca1 on cell transformation and apoptosis induced by radiation. Methods Cell transformation and apoptosis were measured in mouse embryo fibroblasts (MEF and thymocytes respectively. Combinations of wild type and hemizygous genotypes for ATM and BRCA1 were tested in various comparisons. Results Haploinsufficiency of either ATM or BRCA1 resulted in an increase in the incidence of radiation-induced transformation of MEF and a corresponding decrease in the proportion of thymocytes dying an apoptotic death, compared with cells from wild-type animals. Combined haploinsufficiency for both genes resulted in an even larger effect on apoptosis. Conclusions Under stress, the efficiency and capacity for DNA repair mediated by the ATM/BRCA1 cell signalling network depends on the expression levels of both proteins.

  15. Hemizygosity for Atm and Brca1 influence the balance between cell transformation and apoptosis

    International Nuclear Information System (INIS)

    In recent years data from both mouse models and human tumors suggest that loss of one allele of genes involved in DNA repair pathways may play a central role in genomic instability and carcinogenesis. Additionally several examples in mouse models confirmed that loss of one allele of two functionally related genes may have an additive effect on tumor development. To understand some of the mechanisms involved, we examined the role of monoallelic loss or Atm and Brca1 on cell transformation and apoptosis induced by radiation. Cell transformation and apoptosis were measured in mouse embryo fibroblasts (MEF) and thymocytes respectively. Combinations of wild type and hemizygous genotypes for ATM and BRCA1 were tested in various comparisons. Haploinsufficiency of either ATM or BRCA1 resulted in an increase in the incidence of radiation-induced transformation of MEF and a corresponding decrease in the proportion of thymocytes dying an apoptotic death, compared with cells from wild-type animals. Combined haploinsufficiency for both genes resulted in an even larger effect on apoptosis. Under stress, the efficiency and capacity for DNA repair mediated by the ATM/BRCA1 cell signalling network depends on the expression levels of both proteins

  16. A bcl-xS adenovirus selectively induces apoptosis in transformed cells compared to normal mammary cells.

    Science.gov (United States)

    Sumantran, V N; Lee, D S; Woods Ignatoski, K M; Ethier, S P; Wicha, M S

    2000-01-01

    Oncogenes which drive the cell cycle, such as c-myc, can sensitize cells to apoptosis. This suggests the possibility that the expression of genes such as bcl-2 or bcl-xL is required to inhibit apoptosis induced by oncogene expression. We hypothesized that inhibition of Bcl-2/Bcl-xL by the pro-apoptotic Bcl-xS protein, would result in selective induction of apoptosis in mammary carcinoma cells compared to their nontransformed counterparts. Therefore, we compared the effects of Bcl-xS expression delivered by a bcl-xS adenovirus (bcl-xS-Adv) vector, on viability and apoptosis of nontransformed versus transformed mammary epithelial cells. We report that c-myc-transformed murine mammary cells are extremely sensitive to apoptosis induced by the bcl-xS adenovirus (bcl-xS-Adv) vector, whereas immortalized, nontransformed murine mammary cells are relatively resistant to apoptosis induced by this vector. Likewise, human mammary epithelial cells transduced with c-erbB-2 were more sensitive to apoptosis induced by the bcl-xS vector than the nontransformed parental cells. Similar results were obtained when we tested the effects of bcl-xS adenoviral infection on primary normal human mammary epithelial cells and SUM-190 PT cells, (a c-erbB-2 over-expressing human mammary carcinoma cell line) grown on Matrigel. These data are consistent with the hypothesis that inhibition of Bcl-2/Bcl-xL can result in selective killing of cancer cells compared to their nontransformed counterparts.

  17. An embryogenic suspension cell culture system for Agrobacterium-mediated transformation of citrus.

    Science.gov (United States)

    Dutt, M; Grosser, J W

    2010-11-01

    A method for the genetic transformation of several citrus cultivars is described, including cultivars observed to be recalcitrant to conventional epicotyl-mediated transformation. Embryogenic cell suspension cultures, established from unfertilized ovules were used as target tissues for Agrobacterium-mediated transformation. Several modifications were made to the culture environment to investigate factors required for efficient transfer of the T-DNA and the subsequent regeneration of transgenic citrus plants. It was determined that co-cultivation of citrus cells and Agrobacterium in EME medium supplemented with maltose (EME-M) and 100 μM acetosyringone for 5 days at 25°C was optimum for transformation of each of the citrus cultivars. Efficient selection was obtained and escapes were prevented when the antibiotic hygromycin B was used as a selection antibiotic following transformation with an Agrobacterium strain containing hptII in the T-DNA region. Transgenic embryo regeneration and development was enhanced in medium that contained a liquid overlay consisting of a 1:2 mixture of 0.6 M BH3 and 0.15 M EME-M media. PCR and Southern blot analyses confirmed the presence of the T-DNA and the stable integration into the genome of regenerated plants, while RT-PCR demonstrated variable amounts of RNA being transcribed in different transgenic lines. This protocol can create an avenue for insertion of useful traits into any polyembryonic citrus cultivar that can be established as embryogenic cell suspension cultures, including popular specialty mandarins and seedless cultivars.

  18. Comparison of oxygen consumption rates in minimally transformed BALB/3T3 and virus-transformed 3T3B-SV40 cells.

    Science.gov (United States)

    Leznev, E I; Popova, I I; Lavrovskaja, V P; Evtodienko, Y V

    2013-08-01

    In the recent years, bioenergetics of tumor cells and particularly cell respiration have been attracting great attention because of the involvement of mitochondria in apoptosis and growing evidence of the possibility to diagnose and treat cancer by affecting the system of oxidative phosphorylation in mitochondria. In the present work, a comparative study of oxygen consumption in 3T3B-SV40 cells transformed with oncovirus SV40 and parental BALB/3T3 cells was conducted. Such fractions of oxygen consumption as "phosphorylating" respiration coupled to ATP synthesis, "free" respiration not coupled to ATP synthesis, and "reserve" or hidden respiration observed in the presence of protonophore were determined. Maximal respiration was shown to be only slightly decreased in 3T3B-SV40 cells as compared to BALB/3T3. However, in the case of certain fractions of cellular respiration, the changes were significant. "Phosphorylating" respiration was found to be reduced to 54% and "reserve" respiration, on the contrary, increased up to 160% in virus-transformed 3T3B-SV40 cells. The low rate of "phosphorylating" respiration and high "reserve" respiration indicate that under normal incubation conditions the larger part of mitochondrial respiratory chains of the virus-transformed cells is in the resting state (i.e. there is no electron transfer to oxygen). The high "reserve" respiration is suggested to play an important role in preventing apoptosis of 3T3B-SV40 cells.

  19. Platelet-derived stromal cell-derived factor-1 is required for the transformation of circulating monocytes into multipotential cells.

    Directory of Open Access Journals (Sweden)

    Noriyuki Seta

    Full Text Available BACKGROUND: We previously described a primitive cell population derived from human circulating CD14(+ monocytes, named monocyte-derived multipotential cells (MOMCs, which are capable of differentiating into mesenchymal and endothelial lineages. To generate MOMCs in vitro, monocytes are required to bind to fibronectin and be exposed to soluble factor(s derived from circulating CD14(- cells. The present study was conducted to identify factors that induce MOMC differentiation. METHODS: We cultured CD14(+ monocytes on fibronectin in the presence or absence of platelets, CD14(- peripheral blood mononuclear cells, platelet-conditioned medium, or candidate MOMC differentiation factors. The transformation of monocytes into MOMCs was assessed by the presence of spindle-shaped adherent cells, CD34 expression, and the potential to differentiate in vitro into mesenchymal and endothelial lineages. RESULTS: The presence of platelets or platelet-conditioned medium was required to generate MOMCs from monocytes. A screening of candidate platelet-derived soluble factors identified stromal cell-derived factor (SDF-1 as a requirement for generating MOMCs. Blocking an interaction between SDF-1 and its receptor CXCR4 inhibited MOMC generation, further confirming SDF-1's critical role in this process. Finally, circulating MOMC precursors were found to reside in the CD14(+CXCR4(high cell population. CONCLUSION: The interaction of SDF-1 with CXCR4 is essential for the transformation of circulating monocytes into MOMCs.

  20. Graphene as a nanocarrier for tamoxifen induces apoptosis in transformed cancer cell lines of different origins.

    Science.gov (United States)

    Misra, Santosh K; Kondaiah, Paturu; Bhattacharya, Santanu; Rao, C N R

    2012-01-01

    A cationic amphiphile, cholest-5en-3β-oxyethyl pyridinium bromide (PY(+) -Chol), is able to efficiently disperse exfoliated graphene (GR) in water by the physical adsorption of PY(+) -Chol on the surface of GR to form stable, dark aqueous suspensions at room temperature. The GR-PY(+) -Chol suspension can then be used to solubilize Tamoxifen Citrate (TmC), a breast cancer drug, in water. The resulting TmC-GR-PY(+) -Chol is stable for a long time without any precipitation. Fluorescence emission and UV absorption spectra indicate the existence of noncovalent interactions between TmC, GR, and PY(+) -Chol in these suspensions. Electron microscopy shows the existence of segregated GR sheets and TmC 'ribbons' in the composite suspensions. Atomic force microscopy indicates the presence of 'extended' structures of GR-PY(+) -Chol, which grows wider in the presence of TmC. The slow time-dependent release of TmC is noticed in a reconstituted cell culture medium, a property useful as a drug carrier. TmC-GR-PY(+) -Chol selectively enhanced the cell death (apoptosis) of the transformed cancer cells compared to normal cells. This potency is found to be true for a wide range of transformed cancer cells viz. HeLa, A549, ras oncogene-transformed NIH3T3, HepG2, MDA-MB231, MCF-7, and HEK293T compared to the normal cell HEK293 in vitro. Confocal microscopy confirmed the high efficiency of TmC-GR-PY(+) -Chol in delivering the drug to the cells, compared to the suspensions devoid of GR. PMID:22102595

  1. Transformations of the wavelength of the light incident upon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Maruyama, T.; Kitamura, R. [Department of Chemical Engineering, Faculty of Engineering, Kyoto University, Sakyo-ku, 606-8501 Kyoto (Japan)

    2001-10-01

    A method for the improvement of the spectral response of solar cells was proposed. The attachment of the fluorescent plate on the CdS/CdTe cells made the cell sensitive to the light at wavelength below 510nm, transforming the wavelength of the incident light from non-photoresponsive region (below 510nm) to photoresponsive region (above 510nm). A simple analytical model for the maximum power of the cell showed that the increase in the maximum power for the irradiation of sunlight (Air Mass 1.5, direct) was 33%. Furthermore, a possible increase amounted to 40%, if the fluorescent quantum efficiency took the value of 1.0 and that the wavelength of the absorbed light was completely shifted above 510nm where internal quantum efficiency of the solar cell is equal to 1.0.

  2. Cell Transformation and Proteome Alteration in QSG7701 Cells Transfected with Hepatitis C Virus Non-structural Protein 3

    Institute of Scientific and Technical Information of China (English)

    Qiongqiong HE; Deyun FENG; Ruixue CHENG; Zhuchu CHEN; Xuxian XIAO; Zhiqiang XIAO; Cui LI; Bo LI; Pengfei ZHANG; Hui ZHENG

    2007-01-01

    Persistent hepatitis C virus (HCV) infection can cause liver cirrhosis and hepatocellular carcinoma. Non-structural protein 3 (NS3), an important part of HCV, has been implicated in the life cycle of the virus and interacts with host cellular proteins. In this study, we investigated the effect of NS3 protein on cell tranformation and related protein alteration in human hepatocyte QSG7701 cells. The results indicated that stable expression of the NS3 protein in QSG7701 cells induced transformed characters with reduced population doubling time, anchorage-independent growth and tumor development. Fifteen differentially-expressed proteins were separated and identified using 2-D electrophoresis and matrix-assisted laser desorption ionization-time of flight mass spectrometry. Western blot analysis confirmed that the increase of phospho-p44/42 and phospho-p38 proteins was associated with transformed cells. These results supported the view that HCV NS3 protein plays a transforming role and provided some clues to elucidate the carcinogenesis mechanism of HCV-related hepatocellular carcinoma.

  3. Selective cytotoxicity and modification activity of picornaviruses on transformed cell lines

    Directory of Open Access Journals (Sweden)

    Avagyan H. R.

    2011-10-01

    Full Text Available Aim. We do analyze of the dynamics of morphometabolic changes in transformed cells (of susceptoible lines demonstrating resistance to picrnaviral infection. Methods. The study was performed by application of cell culture technology and a complex of cytochemical and cytophotometric assays. Were used picornaviruses from various genu. Results. According to the results obtained, resistant to picornavirus infection cells of different susceptible lines have similar changes in the phenotype. They have decreased number of nucleoli and increased percentage of euploidy (and near euploid. In resistant cells of all cultures the reduction in amount of DNA and RNA both in nucleus and in cytoplasm was found. All these data correlated with the increased euploidy (and near euploid of the resistant population. All picornavirus resistant cells had a less transformed phenotype, and decreased proliferative activity. Decreased nucleolar status becomes apparent by reduction of all nucleolar indices. Conclusions. Picornaviruses on the susceptible cells produce 2 types of changes – selection and modification. Whatever the mechanism, it is specific for an individual virus, since no restrictions occur in case of infection caused by another picornavirus

  4. Persistent exposure to Mycoplasma induces malignant transformation of human prostate cells.

    Directory of Open Access Journals (Sweden)

    Kazunori Namiki

    Full Text Available Recent epidemiologic, genetic, and molecular studies suggest infection and inflammation initiate certain cancers, including those of the prostate. The American Cancer Society, estimates that approximately 20% of all worldwide cancers are caused by infection. Mycoplasma, a genus of bacteria that lack a cell wall, are among the few prokaryotes that can grow in close relationship with mammalian cells, often without any apparent pathology, for extended periods of time. In this study, the capacity of Mycoplasma genitalium, a prevalent sexually transmitted infection, and Mycoplasma hyorhinis, a mycoplasma found at unusually high frequency among patients with AIDS, to induce a malignant phenotype in benign human prostate cells (BPH-1 was evaluated using a series of in vitro and in vivo assays. After 19 weeks of culture, infected BPH-1 cells achieved anchorage-independent growth and increased migration and invasion. Malignant transformation of infected BPH-1 cells was confirmed by the formation of xenograft tumors in athymic mice. Associated with these changes was an increase in karyotypic entropy, evident by the accumulation of chromosomal aberrations and polysomy. This is the first report describing the capacity of M. genitalium or M. hyorhinis infection to lead to the malignant transformation of benign human epithelial cells and may serve as a model to further study the relationship between prostatitis and prostatic carcinogenesis.

  5. MicroRNAs involved in neoplastic transformation of liver cancer stem cells

    Directory of Open Access Journals (Sweden)

    Wang Xinchuan

    2010-12-01

    Full Text Available Abstract Background The existence of cancer stem cells in hepatocellular carcinoma (HCC has been verified by characterizing side population (SP cells based on efflux of Hoechst 33342 dye from stem cells. Recent advances in microRNA (miRNA biology have revealed that miRNAs play an important role in embryonic development and tumorigenesis. However, it is still unclear which miRNAs participate in the neoplastic transformation of liver cancer stem cells (LCSCs during hepatocarcinogenesis. Methods To identify the unique set of miRNAs differentially regulated in LCSCs, we applied SP sorting to primary cultures of F344 rat HCC cancer cells treated with diethylnitrosamine (DEN and normal syngenic fetal liver cells, and the stem-like characteristics of SP cells were verified through detecting expression of CD90.1, AFP and CK-7. Global miRNA expression profiles of two groups of SP cells were screened through microarray platform. Results A total of 68 miRNAs, including miR-10b, miR-21, miR-470*, miR-34c-3p, and let-7i*, were identified as overexpressed in SP of HCC cells compared to fetal liver cells. Ten miRNAs were underexpressed, including miR-200a* and miR-148b*. These miRNAs were validated using stem-loop real-time reverse transcriptase polymerase chain reaction (RT-PCR. Conclusions Our results suggest that LCSCs may have a distinct miRNA expression fingerprint during hepatocarcinogenesis. Dissecting these relationships will provide a new understanding of the function of miRNA in the process of neoplastic transformation of LCSCs.

  6. Cytogenetic characterization and H-ras associated transformation of immortalized human mammary epithelial cells

    Directory of Open Access Journals (Sweden)

    Larivee Siobhan

    2006-05-01

    Full Text Available Abstract Introduction Immortalization is a key step in malignant transformation, but immortalization alone is insufficient for transformation. Human mammary epithelial cell (HMEC transformation is a complex process that requires additional genetic changes beyond immortalization and can be accomplished in vitro by accumulation of genetic changes and expression of H-ras. Methods HMEC were immortalized by serial passaging and transduction with the catalytic subunit of the human telomerase gene (hTERT. The immortalized cells were passaged in vitro and studied by a combination of G- banding and Spectral Karyotyping (SKY. H-ras transduced, hTERT immortalized cells were cloned in soft agar and injected into nude mice. Extensive analysis was performed on the tumors that developed in nude mice, including immunohistochemistry and western blotting. Results Immortal HMEC alone were not tumorigenic in γ-irradiated nude mice and could not grow in soft agar. Late passage hTERT immortalized HMEC from a donor transduced with a retroviral vector containing the mutant, autoactive, human H-ras61L gene acquired anchorage independent growth properties and the capacity for tumorigenic growth in vivo. The tumors that developed in the nude mice were poorly differentiated epithelial carcinomas that continued to overexpress ras. These cells were resistant to doxorubicin mediated G1/S phase arrest but were sensitive to treatment with a farnesyltransferase inhibitor. Conclusion Some of the cytogenetic changes are similar to what is observed in premalignant and malignant breast lesions. Despite these changes, late passage immortal HMEC are not tumorigenic and could only be transformed with overexpression of a mutant H-ras oncogene.

  7. The Characterisation of Pluripotent and Multipotent Stem Cells Using Fourier Transform Infrared Microspectroscopy

    Directory of Open Access Journals (Sweden)

    Mark J. Tobin

    2013-08-01

    Full Text Available Fourier transform infrared (FTIR microspectroscopy shows potential as a benign, objective and rapid tool to screen pluripotent and multipotent stem cells for clinical use. It offers a new experimental approach that provides a holistic measurement of macromolecular composition such that a signature representing the internal cellular phenotype is obtained. The use of this technique therefore contributes information that is complementary to that acquired by conventional genetic and immunohistochemical methods.

  8. Transcriptional Profile of Ki-Ras-Induced Transformation of Thyroid Cells

    DEFF Research Database (Denmark)

    Visconti, Roberta; Federico, Antonella; Coppola, Valeria;

    2007-01-01

    Abstract In the last years, an increasing number of experiments has provided compelling evidence for a casual role of Ras protein mutations, resulting in their constitutive activation, in thyroid carcinogenesis. However, despite the clear involvement of Ras proteins in thyroid carcinogenesis, the...... in human thyroid carcinoma cell lines and tumor samples, our results, therefore, providing a new molecular profile of the genes involved in thyroid neoplastic transformation....

  9. MUTATION OF p53 GENE IN TRANSFORMED RAT TRACHEAL EPITHELIAL CELLS INDUCED BY RADIATION

    Institute of Scientific and Technical Information of China (English)

    赵永良; 吴德昌; 刘国廉; 项晓琼

    1998-01-01

    The highly conserved domain (exon 5-8) of p53 gene in transformed rat tracheal epithelial (RTE) cells was analyzed by means of polymerase chain reaction and single strand conformation polymorphism (PCR-SSCP). The result showed that single strand of exon 8 gene had mobility shift in polyacrylamide nondenaturing gel. DNA sequencing proved the mutation was G→C transversion at condon 265.

  10. Establishment and transformation of telomerase-immortalized human small airway epithelial cells by heavy ions

    Science.gov (United States)

    Zhao, Y. L.; Piao, C. Q.; Hei, T. K.

    Previous studies from this laboratory have identified a number of causally linked genes including the novel tumor suppressor Betaig-h3 that were differentially expressed in radiation induced tumorigenic BEP2D cells. To extend these studies using a genomically more stable bronchial cell line, we show here that ectopic expression of the catalytic subunit of telomerase (hTERT) in primary human small airway epithelial (SAE) cells resulted in the generation of several clonal cell lines that have been continuously in culture for more than 250 population doublings and are considered immortal. Comparably-treated control SAE cells infected with only the viral vector senesced after less than 10 population doublings. The immortalized clones demonstrated anchorage dependent growth and are non-tumorigenic in nude mice. These cells show no alteration in the p53 gene but a decrease in p16 expression. Exponentially growing SAEh cells were exposed to graded doses of 1 GeV/nucleon of 56Fe ions accelerated at the Brookhaven National Laboratory. Irradiated cells underwent gradual phenotypic alterations after extensive in vitro cultivation. Transformed cells developed through a series of successive steps before becoming anchorage independent in semisolid medium. These findings indicate that hTERT-immortalized cells, being diploid and chromosomal stable, should be a useful model in assessing mechanism of radiation carcinogenesis.

  11. Closing the Phenotypic Gap between Transformed Neuronal Cell Lines in Culture and Untransformed Neurons

    Science.gov (United States)

    Myers, Tereance A.; Nickerson, Cheryl A.; Kaushal, Deepak; Ott, C. Mark; HonerzuBentrup, Kerstin; Ramamurthy, Rajee; Nelman-Gonzales, Mayra; Pierson, Duane L.; Philipp, Mario T.

    2008-01-01

    Studies of neuronal dysfunction in the central nervous system (CNS) are frequently limited by the failure of primary neurons to propagate in vitro. Neuronal cell lines can be substituted for primary cells but they often misrepresent normal conditions. We hypothesized that a dimensional (3-D) cell culture system would drive the phenotype of transformed neurons closer to that of untransformed cells. In our studies comparing 3-D versus 2-dimensional (2-D) culture, neuronal SH-SY5Y (SY) cells underwent distinct morphological changes combined with a significant drop in their rate of cell division. Expression of the proto-oncogene N-myc and the RNA binding protein HuD was decreased in 3-D culture as compared to standard 2-D conditions. We observed a decline in the anti-apoptotic protein Bcl-2 in 3-D culture, coupled with increased expression of the pro-apoptotic proteins Bax and Bak. Moreover, thapsigargin (TG)-induced apoptosis was enhanced in the 3-D cells. Microarray analysis demonstrated significantly differing mRNA levels for over 700 genes in the cells of each culture type. These results indicate that a 3-D culture approach narrows the phenotypic gap between neuronal cell lines and primary neurons. The resulting cells may readily be used for in vitro research of neuronal pathogenesis.

  12. In vitro BALB/3T3 cell transformation assay of nonoxynol-9 and 1,4-dioxane

    Energy Technology Data Exchange (ETDEWEB)

    Sheu, C.W.; Moreland, F.M.; Lee, J.K.; Dunkel, V.C.

    1988-01-01

    The spermicidal surfactant nonoxynol-9 (Igepal CO-630, GAF Corp.) and a potential impurity, 1,4-dioxane, were tested in the in vitro cell transformation assay using BALB/3T3 cells. Two treatment periods, 48 hr and 13 days, were used. Nonoxynol-9, tested at levels up to 10 /sup +/g/ml, did not induce transformation, whereas dioxane was very active in the induction type II foci in the cultured BALB/3T3 cells.

  13. Dissection of the transformation of primary human hematopoietic cells by the oncogene NUP98-HOXA9.

    Directory of Open Access Journals (Sweden)

    Enas R Yassin

    Full Text Available NUP98-HOXA9 is the prototype of a group of oncoproteins associated with acute myeloid leukemia. It consists of an N-terminal portion of NUP98 fused to the homeodomain of HOXA9 and is believed to act as an aberrant transcription factor that binds DNA through the homeodomain. Here we show that NUP98-HOXA9 can regulate transcription without binding to DNA. In order to determine the relative contributions of the NUP98 and HOXA9 portions to the transforming ability of NUP98-HOXA9, the effects of NUP98-HOXA9 on primary human CD34+ cells were dissected and compared to those of wild-type HOXA9. In contrast to previous findings in mouse cells, HOXA9 had only mild effects on the differentiation and proliferation of primary human hematopoietic cells. The ability of NUP98-HOXA9 to disrupt the differentiation of primary human CD34+ cells was found to depend primarily on the NUP98 portion, whereas induction of long-term proliferation required both the NUP98 moiety and an intact homeodomain. Using oligonucleotide microarrays in primary human CD34+ cells, a group of genes was identified whose dysregulation by NUP98-HOXA9 is attributable primarily to the NUP98 portion. These include RAP1A, HEY1, and PTGS2 (COX-2. Their functions may reflect the contribution of the NUP98 moiety of NUP98-HOXA9 to leukemic transformation. Taken together, these results suggest that the effects of NUP98-HOXA9 on gene transcription and cell transformation are mediated by at least two distinct mechanisms: one that involves promoter binding through the homeodomain with direct transcriptional activation, and another that depends predominantly on the NUP98 moiety and does not involve direct DNA binding.

  14. Identification and localization of transformed cells in agrobacterium tumefaciens-induced plant tumors

    Science.gov (United States)

    Rezmer; Schlichting; Wachter; Ullrich

    1999-10-01

    Agrobacterium tumefaciens-induced tumors of dicotyledonous plants consist of well-defined vascular bundle-like structures originating from transformed cells. The current view that 25% of the tumor cells are transformed has been re-investigated by using beta-glucuronidase (gus)-gene-containing wild-type bacteria (A281 p35S gus-int). Regularly growing stem and leaf tumors showed irregular GUS-staining patterns in the different plant species, Ricinus communis L., Cucurbita maxima L., Vicia faba L. and Kalanchoe daigremontiana Hamet et Perrier. Variable staining and inconsistency between staining and tumor growth suggested an inhibition of gus expression. By polymerase chain reaction (PCR) and reverse transcriptase-PCR analyses it became evident that gus is also integrated into the DNA of unstainable tumor parts but not expressed. These results and area calculations of tissues unable to contain the bacterial transferred-DNA with gus provide strong evidence that in A. tumefaciens-induced tumors most cells, or even all, are transformed, i.e. ca. 100%. PMID:10550620

  15. Is Transforming Stem Cells to Pancreatic Beta Cells Still the Holy Grail for Type 2 Diabetes?

    Science.gov (United States)

    Kahraman, Sevim; Okawa, Erin R; Kulkarni, Rohit N

    2016-08-01

    Diabetes is a progressive disease affecting millions of people worldwide. There are several medications and treatment options to improve the life quality of people with diabetes. One of the strategies for the treatment of diabetes could be the use of human pluripotent stem cells or induced pluripotent stem cells. The recent advances in differentiation of stem cells into insulin-secreting beta-like cells in vitro make the transplantation of the stem cell-derived beta-like cells an attractive approach for treatment of type 1 and type 2 diabetes. While stem cell-derived beta-like cells provide an unlimited cell source for beta cell replacement therapies, these cells can also be used as a platform for drug screening or modeling diseases. PMID:27313072

  16. Is Transforming Stem Cells to Pancreatic Beta Cells Still the Holy Grail for Type 2 Diabetes?

    Science.gov (United States)

    Kahraman, Sevim; Okawa, Erin R; Kulkarni, Rohit N

    2016-08-01

    Diabetes is a progressive disease affecting millions of people worldwide. There are several medications and treatment options to improve the life quality of people with diabetes. One of the strategies for the treatment of diabetes could be the use of human pluripotent stem cells or induced pluripotent stem cells. The recent advances in differentiation of stem cells into insulin-secreting beta-like cells in vitro make the transplantation of the stem cell-derived beta-like cells an attractive approach for treatment of type 1 and type 2 diabetes. While stem cell-derived beta-like cells provide an unlimited cell source for beta cell replacement therapies, these cells can also be used as a platform for drug screening or modeling diseases.

  17. Non-germ cell tumours arising in germ cell tumours (teratoma with malignant transformation) in men: CT and MR findings

    Energy Technology Data Exchange (ETDEWEB)

    Athanasiou, A. [Department of Radiology, Institut Gustave-Roussy, Villejuif (France); Department of Radiology, Institut Curie, Paris (France)], E-mail: alexandra.athanasiou@curie.net; Vanel, D. [Department of Radiology, Institut Gustave-Roussy, Villejuif (France); Department of Radiology, Istituti Ortopedici Rizzoli, Bologna (Italy); El Mesbahi, O. [Department of Medicine, Institut Gustave-Roussy, Villejuif (France); Theodore, C. [Department of Medicine, Institut Gustave-Roussy, Villejuif (France); Department of Oncology, Hopital Foch, Suresnes (France); Fizazi, K. [Department of Medicine, Institut Gustave-Roussy, Villejuif (France)

    2009-02-15

    Purpose: To describe the imaging findings of germ cell tumours (GCT) containing non-germ cell malignant components (also designated teratoma with malignant transformation or TMT). Patients and methods: The records of 14 male patients with GCT and a non-germ cell histological component TMT were retrospectively reviewed. All patients had computed tomography (CT) and/or magnetic resonance (MR) studies before and after initial surgery and chemotherapy, as well as during follow-up. Imaging findings were correlated with the response to treatment and with overall survival. Pathological evaluation, immunohistochemistry, serum alpha-fetoprotein (AFP) and human chorionic gonadotropin (HCG) were also taken into consideration. Sarcoma was identified in 10 out of 14 patients, with rhabdomyosarcoma ranking first (n = 4), followed by osteosarcoma (n = 2), fusiform cell sarcoma (n = 1), undifferentiated sarcoma (n = 1), neurosarcoma (n = 1) and myxoid sarcoma (n = 1). Other histological types of malignant transformation included adenocarcinoma (n = 3) and bronchoalveolar carcinoma (n = 1). Overall, 9 patients relapsed at a median time of 84 months (range 60-168). Results: Non-GCT malignant transformation was identified in the retroperitoneum (5), testis (3), mediastinum (3), peritoneum (2) and lungs (1). The CT and MR imaging findings before treatment and after relapse were evaluated with emphasis on imaging features that could possibly imply the presence of malignant transformation (heterogeneously enhancing soft-tissue masses, ossified masses with calcified lymph nodes, diffuse epiploic thickening associated with ascites and peritoneal nodules, pulmonary alveolar infiltration with septal thickening). All but 1 patient with TMT presented with nodal and distant metastases. The prognosis was poor: within a median follow-up of 59 months (range 3-180), 4 out of 14 patients were alive. Conclusion: TMT is rare and associated with poorer survival compared to GCT. Imaging can be useful

  18. Dysregulation of gene expression in the artificial human trisomy cells of chromosome 8 associated with transformed cell phenotypes.

    Directory of Open Access Journals (Sweden)

    Hisakatsu Nawata

    Full Text Available A change in chromosome number, known as aneuploidy, is a common characteristic of cancer. Aneuploidy disrupts gene expression in human cancer cells and immortalized human epithelial cells, but not in normal human cells. However, the relationship between aneuploidy and cancer remains unclear. To study the effects of aneuploidy in normal human cells, we generated artificial cells of human primary fibroblast having three chromosome 8 (trisomy 8 cells by using microcell-mediated chromosome transfer technique. In addition to decreased proliferation, the trisomy 8 cells lost contact inhibition and reproliferated after exhibiting senescence-like characteristics that are typical of transformed cells. Furthermore, the trisomy 8 cells exhibited chromosome instability, and the overall gene expression profile based on microarray analyses was significantly different from that of diploid human primary fibroblasts. Our data suggest that aneuploidy, even a single chromosome gain, can be introduced into normal human cells and causes, in some cases, a partial cancer phenotype due to a disruption in overall gene expression.

  19. Biological effects of radiation: The induction of malignant transformation and programmed cell death

    International Nuclear Information System (INIS)

    In the Chernobyl explosions and fire, powderized nuclear fuel was released from the reactor core, causing an unexpected fallout. X-ray analysis and scanning electron microscopy showed that the isolated single particles were essentially pure uranium. These uranium aerosols contained all of the nonvolatile fission products, including the b-emitters, 95Zr, 103Ru, 106Ru, 141Ce, and 144Ce. The hot particles are extremely effective in inducing malignant transformation in mouse fibroblast cells in vitro. The major factor responsible for this effect is focus promotion caused by a wound-mediated permanent increase in cell proliferation (mitogenesis associated with mutagenesis). Transformed foci were analysed for the activation of c-abl, c-erb-A, c-erb-B, c-fms, c-fos, c-myb, c-myc, c-Ha-ras, c-Ki-ras, c-sis, and c-raf oncogenes at the transcriptional level. The pattern of oncogene activation was found to vary from focus to focus. Long interspersed repeated DNA (L1 or LINE makes up a class of mobile genetic elements which can amplify in the cell genome by retroposition. This element is spontaneously transcriptionally activated at a critical population density and later amplified in rat chloroleukaemia cells. UV light and ionizing radiation induce this activation prematurely, and the activation is followed by programmed cell death (apoptosis) in a sequence of events identical to that seen in LIRn activation occurring spontaneously

  20. Attenuated total reflectance Fourier transform infrared spectroscopy method to differentiate between normal and cancerous breast cells.

    Science.gov (United States)

    Lane, Randy; See, Seong S

    2012-09-01

    Attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) is used to find the structural differences between cancerous breast cells (MCF-7 line) and normal breast cells (MCF-12F line). Gold nanoparticles were prepared and the hydrodynamic diameter of the gold nanoparticles found to be 38.45 nm. The Gold nanoparticles were exposed to both MCF-7 and MCF-12F cells from lower to higher concentrations. Spectroscopic studies founds nanoparticles were within the cells, and increasing the nanoparticles concentration inside the cells also resulted in sharper IR peaks as a result of localized surface Plasmon resonance. Asymmetric and symmetric stretching and bending vibrations between phosphate, COO-, CH2 groups were found to give negative shifts in wavenumbers and a decrease in peak intensities when going from noncancerous to cancerous cells. Cellular proteins produced peak assignments at the 1542 and 1644 cm(-1) wavenumbers which were attributed to the amide I and amide II bands of the polypeptide bond of proteins. Significant changes were found in the peak intensities between the cell lines in the spectrum range from 2854-2956 cm(-1). Results show that the concentration range of gold nanoparticles used in this research showed no significant changes in cell viability in either cell line. Therefore, we believe ATR-FTIR and gold nanotechnology can be at the forefront of cancer diagnosis for some time to come.

  1. Immunoreactive transforming growth factor alpha and epidermal growth factor in oral squamous cell carcinomas

    DEFF Research Database (Denmark)

    Therkildsen, M H; Poulsen, Steen Seier; Bretlau, P

    1993-01-01

    Forty oral squamous cell carcinomas have been investigated immunohistochemically for the presence of transforming growth factor alpha (TGF-alpha) and epidermal growth factor (EGF). The same cases were recently characterized for the expression of EGF-receptors. TGF-alpha was detected...... with a monoclonal mouse antibody and EGF with polyclonal rabbit antiserum. Thirty-five of the tumours were positive for TGF-alpha and 26 of the tumours for EGF. None of the poorly differentiated tumours was positive for EGF, but they all were for TGF-alpha. In sections including normal differentiated oral mucosa......, the cells above the basal cell layer were positive for both TGF-alpha and EGF. The same staining pattern was observed in oral mucosa obtained from healthy persons. In moderately to well differentiated carcinomas, the immunoreactivity was mainly confined to the cytologically more differentiated cells, thus...

  2. In vivo expression of immunosuppressive cytokines in human papillomavirus-transformed cervical cancer cells.

    Science.gov (United States)

    Alcocer-González, Juan Manuel; Berumen, Jaime; Taméz-Guerra, Reyes; Bermúdez-Morales, Víctor; Peralta-Zaragoza, Oscar; Hernández-Pando, Rogelio; Moreno, José; Gariglio, Patricio; Madrid-Marina, Vicente

    2006-01-01

    Genital human Papillomavirus infection is common and only a minor fraction of infected subjects develop progressing cervical epithelial lesions or cancer. Bypassing local immune responses is important for the development of cervical cancer. In this work we determined the cytokine pattern in samples from patients with cervical cancer. Thus, we examined the local mRNA expression profile of helper T cell type 1 (Th1), Th2, and Th3 cytokines in HPV-positive cervical cancer biopsies by reverse transcription-polymerase chain reaction. Our data indicate that 80% of the tumors expressed low levels of CD4 mRNA, with all of them expressing higher CD8 mRNA levels. Most tumors expressed interleukin (IL)-4 and IL-10 mRNAs and, most importantly, all of them expressed transforming growth factor (TGF)-beta1 and interferon gamma mRNA. None of the tumors studied expressed IL-12, IL-6, or tumor necrosis factor (TNF) mRNA. Immunohistochemical analysis identified IL-10 only in tumor cells and koilocytic cells, but not in tumor-infiltrating lymphocytes, suggesting that IL-10-producing cells are those transformed by HPV. We found a correlation between immunostaining for IL-10 protein and the level of IL-10 mRNA expression. Moreover, supernatants from HPV-transformed cell cultures contained IL-10 and TGF- beta1. Our findings indicate a predominant expression of immunosuppressive cytokines, which might help downregulate tumor-specific immune responses in the microenvironment of the tumor. This information may be useful for cervical cancer immunotherapies or for therapeutic vaccine design against Human Papillomavirus. PMID:16987066

  3. Nucleotide sequence determination of the region in adenovirus 5 DNA involved in cell transformation

    International Nuclear Information System (INIS)

    A description is given of investigations into the primary structure of the transforming region of adenovirus type 5 DNA. The phenomenon of cell transformation is discussed in general terms and the principles of a number of fairly recent techniques, which have been in use for DNA sequence determination since 1975 are dealt with. A few of the author's own techniques are described which deal both with nucleotide sequence analysis and with the determination of DNA cleavage sites of restriction endonucleases. The results are given of the mapping of cleavage sites in the HpaI-E fragment of adenovirus DNA of HpaII, HaeIII, AluI, HinfI and TaqI and of the determination of the nucleotide sequence in the transforming region of adenovirus type 5 DNA. The results of the sequence determination of the Ad5 HindIII-G fragment are discussed in relation with the investigation on the transforming proteins isolated from in vitro and in vivo synthesizing systems. Labelling procedures of DNA are described including the exonuclease III/DNA polymerase 1 method and TA polynucleotide kinase labelling of DNA fragments. (Auth.)

  4. Spontaneous transformation of human granulosa cell tumours into an aggressive phenotype: a metastasis model cell line

    International Nuclear Information System (INIS)

    Granulosa cell tumours (GCTs) are frequently seen in menopausal women and are relatively indolent. Although the physiological properties of normal granulosa cells have been studied extensively, little is known about the molecular mechanism of GCT progression. Here, we characterise the unique behavioural properties of a granulosa tumour cell line, KGN cells, for the molecular analysis of GCT progression. Population doubling was carried out to examine the proliferation capacity of KGN cells. Moreover, the invasive capacity of these cells was determined using the in vitro invasion assay. The expression level of tumour markers in KGN cells at different passages was then determined by Western blot analysis. Finally, the growth and metastasis of KGN cells injected subcutaneously (s.c.) into nude mice was observed 3 months after injection. During in vitro culture, the advanced passage KGN cells grew 2-fold faster than the early passage cells, as determined by the population doubling assay. Moreover, we found that the advanced passage cells were 2-fold more invasive than the early passage cells. The expression pattern of tumour markers, such as p53, osteopontin, BAX and BAG-1, supported the notion that with passage, KGN cells became more aggressive. Strikingly, KGN cells at both early and advanced passages metastasized to the bowel when injected s.c. into nude mice. In addition, more tumour nodules were formed when the advanced passage cells were implanted. KGN cells cultured in vitro acquire an aggressive phenotype, which was confirmed by the analysis of cellular activities and the expression of biomarkers. Interestingly, KGN cells injected s.c. are metastatic with nodule formation occurring mostly in the bowel. Thus, this cell line is a good model for analysing GCT progression and the mechanism of metastasis in vivo

  5. Abnormal Expression of Eukaryotic Translation Factors in Malignant Transformed Human Bronchial Epithelial Cells Induced by Crystalline Nickel Sulfide

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Objective To study the oncogenic potential of mouse translation initiation factor 3 (TIF3) and elongation factor-1δ (TEF-1δ) in malignant transformed human bronchial epithelial cells induced by crystalline nickel sulfide (NiS). Methods Abnormal expressions of human TIF3 and TEF-1δ genes in two kinds of NiS-transformed cells and NiS-tumorigenic cell lines were investigated and analyzed by the reverse transcript polymerase chain reaction (RT-PCR) and fluorescent quantitative polymerase chain reaction (FQ-PCR), respectively. Results RT-PCR analysis primarily showed that both human TIF3 and TEF-1δ mRNA expressions in two kinds of NiS-transformed cells and NiS-tumorigenic cell lines were increased as compared with controls. FQ-PCR assay showed that the levels of TIF3 expressions in the transformed cells and tumorigenic cells were 3 and 4 times higher respectively, and the elevated expressions of TEF-1δ cDNA copies were 2.7- to 3.5-fold in transformed cells and 4.1- to 5.2-fold in tumorigenic cells when compared with non-transformed cells, indicating that the over-expressions of human TIF3 and TEF-1δ genes were related to malignant degree of the cells induced by nickel. Conclusions These findings demonstrate that there are markedly abnormal expressions of TIF3 and TEF-1δ genes during malignant transformation of human bronchial epithelial cell lines induced by crystalline NiS. They seem to be the molecular mechanisms potentially responsible for human carcinogensis due to nickel.

  6. Transforming Growth Factor-β Expression Induced by Rhinovirus Infection in Respiratory Epithelial Cells

    Institute of Scientific and Technical Information of China (English)

    Amrita DOSANJH

    2006-01-01

    Rhinovirus infection of the lower airways is now a recognized disease, associated with bronchiolitis and asthma. The bronchial epithelial cells are the host cells when rhinovirus infection occurs in the airway. It was hypothesized that a pro-fibrotic growth factor response may occur in these infected cells,leading to production of a key transforming growth factor, TGF-β-1. Bronchial epithelial cells were inoculated with human rhinovirus and compared at day 1, 3 and 5 to control non-infected cells. Cell culture supernatant fluid and cellular RNA were isolated. The amount of released TGF-β protein was measured by enzyme-linked immunosorbent assay (ELISA). Expression of TGF-β at the level of transcription was measured by polymerase chain reaction (PCR) and gel electrophoresis. The results show that at all time points studied, TGF-β production is greater in the infected cells, as demonstrated by ELISA (P<0.05) and by semiquantitative PCR analysis. It was concluded that bronchial epithelial cells infected with common cold virus and rhinovirus, showed higher levels of TGF-β. The production of TGF-β may be indicative of a normal repair mechanism to counter inflammation, or in the setting of persistent asthma, could potentially lead to increased fibrosis and collagen deposition.

  7. Critical kinetic control of non-stoichiometric intermediate phase transformation for efficient perovskite solar cells

    Science.gov (United States)

    Rong, Yaoguang; Venkatesan, Swaminathan; Guo, Rui; Wang, Yanan; Bao, Jiming; Li, Wenzhi; Fan, Zhiyong; Yao, Yan

    2016-06-01

    Organometal trihalide perovskites (OTP) have attracted significant attention as a low-cost and high-efficiency solar cell material. Due to the strong coordination between lead iodide (PbI2) and dimethyl sulfoxide (DMSO) solvent, a non-stoichiometric intermediate phase of MA2Pb3I8(DMSO)2 (MA = CH3NH3+) usually forms in the one-step deposition method that plays a critical role in attaining high power conversion efficiency. However, the kinetic understanding of how the non-stoichiometric intermediate phase transforms during thermal annealing is currently absent. In this work, we investigated such a phase transformation and provided a clear picture of three phase transition pathways as a function of annealing conditions. The interdiffusion of MAI and DMSO varies strongly with the annealing temperature and time, thus determining the final film composition and morphology. A surprising finding reveals that the best performing cells contain ~18% of the non-stoichiometric intermediate phase, instead of pure phase OTP. The presence of such an intermediate phase enables smooth surface morphology and enhances the charge carrier lifetime. Our results highlight the importance of the intermediate phase growth kinetics that could lead to large-scale production of efficient solution processed perovskite solar cells.Organometal trihalide perovskites (OTP) have attracted significant attention as a low-cost and high-efficiency solar cell material. Due to the strong coordination between lead iodide (PbI2) and dimethyl sulfoxide (DMSO) solvent, a non-stoichiometric intermediate phase of MA2Pb3I8(DMSO)2 (MA = CH3NH3+) usually forms in the one-step deposition method that plays a critical role in attaining high power conversion efficiency. However, the kinetic understanding of how the non-stoichiometric intermediate phase transforms during thermal annealing is currently absent. In this work, we investigated such a phase transformation and provided a clear picture of three phase transition

  8. Apoptin induces apoptosis in human transformed and malignant cells but not in normal cells

    NARCIS (Netherlands)

    Dane-Oorschot, A.A.A.M. van; Fischer, D.F.; Grimbergen, J.M.; Klein, B.; Zhuang, S.M.; Falkenburg, J.H.F.; Backendorf, C.; Quax, P.H.A.; Eb, A.J. van der; Noteborn, M.H.M.

    1997-01-01

    The chicken anemia virus protein apoptin induces a p53-independent, Bcl- 2-insensitive type of apoptosis in various human tumor cells. Here, we show that, in vitro, apoptin fails to induce programmed cell death in normal lymphoid, dermal, epidermal, endothelial, and smooth-muscle cells. However, whe

  9. PRMT5 Is Upregulated in HTLV-1-Mediated T-Cell Transformation and Selective Inhibition Alters Viral Gene Expression and Infected Cell Survival.

    Science.gov (United States)

    Panfil, Amanda R; Al-Saleem, Jacob; Howard, Cory M; Mates, Jessica M; Kwiek, Jesse J; Baiocchi, Robert A; Green, Patrick L

    2015-12-30

    Human T-cell leukemia virus type-1 (HTLV-1) is a tumorigenic retrovirus responsible for development of adult T-cell leukemia/lymphoma (ATLL). This disease manifests after a long clinical latency period of up to 2-3 decades. Two viral gene products, Tax and HBZ, have transforming properties and play a role in the pathogenic process. Genetic and epigenetic cellular changes also occur in HTLV-1-infected cells, which contribute to transformation and disease development. However, the role of cellular factors in transformation is not completely understood. Herein, we examined the role of protein arginine methyltransferase 5 (PRMT5) on HTLV-1-mediated cellular transformation and viral gene expression. We found PRMT5 expression was upregulated during HTLV-1-mediated T-cell transformation, as well as in established lymphocytic leukemia/lymphoma cell lines and ATLL patient PBMCs. shRNA-mediated reduction in PRMT5 protein levels or its inhibition by a small molecule inhibitor (PRMT5i) in HTLV-1-infected lymphocytes resulted in increased viral gene expression and decreased cellular proliferation. PRMT5i also had selective toxicity in HTLV-1-transformed T-cells. Finally, we demonstrated that PRMT5 and the HTLV-1 p30 protein had an additive inhibitory effect on HTLV-1 gene expression. Our study provides evidence for PRMT5 as a host cell factor important in HTLV-1-mediated T-cell transformation, and a potential target for ATLL treatment.

  10. Differential DNA methylation profile of key genes in malignant prostate epithelial cells transformed by inorganic arsenic or cadmium

    Energy Technology Data Exchange (ETDEWEB)

    Pelch, Katherine E.; Tokar, Erik J. [National Toxicology Program Laboratory, Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709 (United States); Merrick, B. Alex [Molecular Toxicology and Informatics Group, Biomolecular Screening Branch, Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Morrisville, NC 27560 (United States); Waalkes, Michael P., E-mail: waalkes@niehs.nih.gov [National Toxicology Program Laboratory, Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709 (United States)

    2015-08-01

    Previous work shows altered methylation patterns in inorganic arsenic (iAs)- or cadmium (Cd)-transformed epithelial cells. Here, the methylation status near the transcriptional start site was assessed in the normal human prostate epithelial cell line (RWPE-1) that was malignantly transformed by 10 μM Cd for 11 weeks (CTPE) or 5 μM iAs for 29 weeks (CAsE-PE), at which time cells showed multiple markers of acquired cancer phenotype. Next generation sequencing of the transcriptome of CAsE-PE cells identified multiple dysregulated genes. Of the most highly dysregulated genes, five genes that can be relevant to the carcinogenic process (S100P, HYAL1, NTM, NES, ALDH1A1) were chosen for an in-depth analysis of the DNA methylation profile. DNA was isolated, bisulfite converted, and combined bisulfite restriction analysis was used to identify differentially methylated CpG sites, which was confirmed with bisulfite sequencing. Four of the five genes showed differential methylation in transformants relative to control cells that was inversely related to altered gene expression. Increased expression of HYAL1 (> 25-fold) and S100P (> 40-fold) in transformants was correlated with hypomethylation near the transcriptional start site. Decreased expression of NES (> 15-fold) and NTM (> 1000-fold) in transformants was correlated with hypermethylation near the transcriptional start site. ALDH1A1 expression was differentially expressed in transformed cells but was not differentially methylated relative to control. In conclusion, altered gene expression observed in Cd and iAs transformed cells may result from altered DNA methylation status. - Highlights: • Cd and iAs are known human carcinogens, yet neither appears directly mutagenic. • Prior data suggest epigenetic modification plays a role in Cd or iAs induced cancer. • Altered methylation of four misregulated genes was found in Cd or iAs transformants. • The resulting altered gene expression may be relevant to cellular

  11. Differential DNA methylation profile of key genes in malignant prostate epithelial cells transformed by inorganic arsenic or cadmium

    International Nuclear Information System (INIS)

    Previous work shows altered methylation patterns in inorganic arsenic (iAs)- or cadmium (Cd)-transformed epithelial cells. Here, the methylation status near the transcriptional start site was assessed in the normal human prostate epithelial cell line (RWPE-1) that was malignantly transformed by 10 μM Cd for 11 weeks (CTPE) or 5 μM iAs for 29 weeks (CAsE-PE), at which time cells showed multiple markers of acquired cancer phenotype. Next generation sequencing of the transcriptome of CAsE-PE cells identified multiple dysregulated genes. Of the most highly dysregulated genes, five genes that can be relevant to the carcinogenic process (S100P, HYAL1, NTM, NES, ALDH1A1) were chosen for an in-depth analysis of the DNA methylation profile. DNA was isolated, bisulfite converted, and combined bisulfite restriction analysis was used to identify differentially methylated CpG sites, which was confirmed with bisulfite sequencing. Four of the five genes showed differential methylation in transformants relative to control cells that was inversely related to altered gene expression. Increased expression of HYAL1 (> 25-fold) and S100P (> 40-fold) in transformants was correlated with hypomethylation near the transcriptional start site. Decreased expression of NES (> 15-fold) and NTM (> 1000-fold) in transformants was correlated with hypermethylation near the transcriptional start site. ALDH1A1 expression was differentially expressed in transformed cells but was not differentially methylated relative to control. In conclusion, altered gene expression observed in Cd and iAs transformed cells may result from altered DNA methylation status. - Highlights: • Cd and iAs are known human carcinogens, yet neither appears directly mutagenic. • Prior data suggest epigenetic modification plays a role in Cd or iAs induced cancer. • Altered methylation of four misregulated genes was found in Cd or iAs transformants. • The resulting altered gene expression may be relevant to cellular

  12. Dysregulation of Bmi1 promotes malignant transformation of hepatic progenitor cells.

    Science.gov (United States)

    Zhang, R; Wu, W R; Shi, X D; Xu, L B; Zhu, M S; Zeng, H; Liu, C

    2016-01-01

    Adult hepatic progenitor cells (HPCs) are involved in a wide range of human liver diseases, including hepatocellular carcinoma (HCC). Bmi1 has been reported to have vital roles in stem cell self-renewal and carcinogenesis. We have previously demonstrated that Bmi1 is upregulated in HCC with bile duct tumor thrombi, a subtype of HCC characterized by profuse expression of hepatic stem cell markers. However, the function of Bmi1 in HPCs has not yet been well elucidated. The current study was designed to investigate the effects of Bmi1 on the biological properties of rat HPCs. To accomplish this, Bmi1 was silenced or enhanced in two HPC cell lines (WB-F344 and OC3) by, respectively, using either small interfering RNA against Bmi1 or a forced Bmi1 expression retroviral vector. The biological functions of Bmi1 in HPCs were investigated through cell proliferation assays, colony-formation assays, cell cycle analysis and invasion assays, as well as through xenograft-formation assays. In this study, genetic depletion of Bmi1 repressed cell proliferation, colony formation and invasion in both assessed HPC cell lines relative to controls. Conversely, forced expression of Bmi1 in two HPCs cell lines promoted cell proliferation, colony formation and invasion in vitro. Aldehyde dehydrogenase (ALDH) assay revealed a significant increase in the number of ALDH-positive cells following the forced expression of Bmi1 in HPCs. Most importantly, transplantation of forced Bmi1 expression HPCs into nude mice resulted in the formation of tumors with histological features of poorly differentiated HCC. Taken together, our findings indicate that forced expression of Bmi1 promotes the malignant transformation of HPCs, suggesting Bmi1 might be a potential molecular target for the treatment of HCC. PMID:26926789

  13. Biochemical transformation of deoxythymidine kinase-deficient mouse cells with uv-irradiated equine herpesvirus type 1

    Energy Technology Data Exchange (ETDEWEB)

    Allen, G.P.; McGowan, J.J.; Gentry, G.A.; Randall, C.C.

    1978-10-01

    A line of 3T3 mouse cells lacking deoxythymidine kinase (dTK/sup -/) was stably transformed to the dTK/sup +/ phenotype after exposure to uv-irradiated equine herpesvirus type 1 (EHV-1). Biochemical transformants were isolated in a system selective for the dTK/sup +/ phenotype (Eagle minimal essential medium containing 10/sup -4/ M hypoxanthine, 6 x 10/sup -7/ M aminopterin, and 2 x 10/sup -5/ M deoxythymidine). Transformation was accompanied by the acquisition of a dTK activity with immunological, electrophoretic, and biochemical characteristics identical to those of the dTK induced by EHV-1 during productive infection. The transformed cells have been maintained in selective culture medium for more than 50 passages and have retained the capacity to express EHV-1-specific antigens. Spontaneous release of infectious virus has not been detected in the transformed lines, and the cells were not oncogenic for athymic nude mice. In contrast to normal dTK/sup +/ 3T3 cells, EHV-1 transformants were unable to grow in the presence of arabinosylthymine, a drug selectively phosphorylated by herpesvirus-coded dTK's. These results indicate that a portion of the EHV-1 genome is able to persist in the transformed cells for many generations and be expressed as an enzymatically active viral gene product.

  14. Influence of dose rate on the transformation of Syrian hamster embryo cells by fission-spectrum neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Jones, C.A.; Sedita, B.A.; Hill, C.K.; Elkind, M.M.

    1988-01-01

    Several explanations for this neutron dose-rate effect have been proposed, but further investigation is necessary to determine the mechanisms involved. In all cell transformation studies to date the immortalized, aneuploid 10T1/2 cell-line has been used. These cells may be premalignant; thus their response characteristics and, in particular, the nature of the transformation event, might differ from that in a normal, fibroblast cell. One reason for the present study was to determine whether the low-dose-rate effect of fission neutrons could be demonstrated in normal cells. If so, a normal cell system, which would more closely resemble a normal in vivo system, could be used for mechanistic studies. We chose Syrian hamster embryo (SHE) fibroblasts which are normal, diploid cells with a limited life span in culture. Upon exposure to low doses of ionizing radiation, the fraction of the cells that are transformed can be identified in a standard 8--10 day colony assay by examining their clonal morphology. Transformed cells form colonies with a dense, criss-crossed or piled-up structure. A high percentage of the transformed colonies can be further propagated and will acquire additional neoplastic characteristics; i.e., anchorage independence, immortality, altered proteolytic activity, karyotype alterations, and finally, tumorigenicity.

  15. Automated cervical precancerous cells screening system based on Fourier transform infrared spectroscopy features

    Science.gov (United States)

    Jusman, Yessi; Mat Isa, Nor Ashidi; Ng, Siew-Cheok; Hasikin, Khairunnisa; Abu Osman, Noor Azuan

    2016-07-01

    Fourier transform infrared (FTIR) spectroscopy technique can detect the abnormality of a cervical cell that occurs before the morphological change could be observed under the light microscope as employed in conventional techniques. This paper presents developed features extraction for an automated screening system for cervical precancerous cell based on the FTIR spectroscopy as a second opinion to pathologists. The automated system generally consists of the developed features extraction and classification stages. Signal processing techniques are used in the features extraction stage. Then, discriminant analysis and principal component analysis are employed to select dominant features for the classification process. The datasets of the cervical precancerous cells obtained from the feature selection process are classified using a hybrid multilayered perceptron network. The proposed system achieved 92% accuracy.

  16. The role of mesenchymal stem cells in promoting the transformation of androgen-dependent human prostate cancer cells into androgen-independent manner

    OpenAIRE

    Jiwen Cheng; Keqin Yang; Qingyun Zhang; Yang Yu; Qinggui Meng; Ning Mo; Yang Zhou; Xianlin Yi; Chengzhong Ma; Aming Lei; Yan Liu

    2016-01-01

    Mesenchymal stem cells (MSCs) play an important role in the development of human prostate cancer (PCa). However, the role of MSCs in the transformation of androgen-dependent human PCa cells into androgen-independent manner has been poorly understood. In this study, we investigated the underlying mechanism of MSCs in promoting PCa cells from androgen-dependent into androgen-independent manner. Firstly, we demonstrated that MSCs could affect the transformation of androgen-dependent human PCa ce...

  17. Gene 33/Mig6 inhibits hexavalent chromium-induced DNA damage and cell transformation in human lung epithelial cells

    Science.gov (United States)

    Park, Soyoung; Li, Cen; Zhao, Hong; Darzynkiewicz, Zbigniew; Xu, Dazhong

    2016-01-01

    Hexavalent Chromium [Cr(VI)] compounds are human lung carcinogens and environmental/occupational hazards. The molecular mechanisms of Cr(VI) carcinogenesis appear to be complex and are poorly defined. In this study, we investigated the potential role of Gene 33 (ERRFI1, Mig6), a multifunctional adaptor protein, in Cr(VI)-mediated lung carcinogenesis. We show that the level of Gene 33 protein is suppressed by both acute and chronic Cr(VI) treatments in a dose- and time-dependent fashion in BEAS-2B lung epithelial cells. The inhibition also occurs in A549 lung bronchial carcinoma cells. Cr(VI) suppresses Gene 33 expression mainly through post-transcriptional mechanisms, although the mRNA level of gene 33 also tends to be lower upon Cr(VI) treatments. Cr(VI)-induced DNA damage appears primarily in the S phases of the cell cycle despite the high basal DNA damage signals at the G2M phase. Knockdown of Gene 33 with siRNA significantly elevates Cr(VI)-induced DNA damage in both BEAS-2B and A549 cells. Depletion of Gene 33 also promotes Cr(VI)-induced micronucleus (MN) formation and cell transformation in BEAS-2B cells. Our results reveal a novel function of Gene 33 in Cr(VI)-induced DNA damage and lung epithelial cell transformation. We propose that in addition to its role in the canonical EGFR signaling pathway and other signaling pathways, Gene 33 may also inhibit Cr(VI)-induced lung carcinogenesis by reducing DNA damage triggered by Cr(VI). PMID:26760771

  18. Direct detection of diverse metabolic changes in virally transformed and tax-expressing cells by mass spectrometry.

    Directory of Open Access Journals (Sweden)

    Prabhakar Sripadi

    Full Text Available BACKGROUND: Viral transformation of a cell starts at the genetic level, followed by changes in the proteome and the metabolome of the host. There is limited information on the broad metabolic changes in HTLV transformed cells. METHODS AND PRINCIPAL FINDINGS: Here, we report the detection of key changes in metabolites and lipids directly from human T-lymphotropic virus type 1 and type 3 (HTLV1 and HTLV3 transformed, as well as Tax1 and Tax3 expressing cell lines by laser ablation electrospray ionization (LAESI mass spectrometry (MS. Comparing LAESI-MS spectra of non-HTLV1 transformed and HTLV1 transformed cells revealed that glycerophosphocholine (PC lipid components were dominant in the non-HTLV1 transformed cells, and PC(O-32:1 and PC(O-34:1 plasmalogens were displaced by PC(30:0 and PC(32:0 species in the HTLV1 transformed cells. In HTLV1 transformed cells, choline, phosphocholine, spermine and glutathione, among others, were downregulated, whereas creatine, dopamine, arginine and AMP were present at higher levels. When comparing metabolite levels between HTLV3 and Tax3 transfected 293T cells, there were a number of common changes observed, including decreased choline, phosphocholine, spermine, homovanillic acid, and glycerophosphocholine and increased spermidine and N-acetyl aspartic acid. These results indicate that the lipid metabolism pathway as well as the creatine and polyamine biosynthesis pathways are commonly deregulated after expression of HTLV3 and Tax3, indicating that the noted changes are likely due to Tax3 expression. N-acetyl aspartic acid is a novel metabolite that is upregulated in all cell types and all conditions tested. CONCLUSIONS AND SIGNIFICANCE: We demonstrate the high throughput in situ metabolite profiling of HTLV transformed and Tax expressing cells, which facilitates the identification of virus-induced perturbations in the biochemical processes of the host cells. We found virus type-specific (HTLV1 vs. HTLV3

  19. Tetraploid cells from cytokinesis failure induce aneuploidy and spontaneous transformation of mouse ovarian surface epithelial cells

    OpenAIRE

    Lv, Lei; Zhang, Tianwei; Yi, Qiyi; Huang, Yun; Wang, Zheng; Hou, Heli; Zhang, Huan; Zheng, Wei; Hao, Qiaomei; Guo, Zongyou; Howard J Cooke; Shi, Qinghua

    2012-01-01

    Most ovarian cancers originate from the ovarian surface epithelium and are characterized by aneuploid karyotypes. Aneuploidy, a consequence of chromosome instability, is an early event during the development of ovarian cancers. However, how aneuploid cells are evolved from normal diploid cells in ovarian cancers remains unknown. In the present study, cytogenetic analyses of a mouse syngeneic ovarian cancer model revealed that diploid mouse ovarian surface epithelial cells (MOSECs) experienced...

  20. The target cell of transformation is distinct from the leukemia stem cell in murine CALM/AF10 leukemia models.

    Science.gov (United States)

    Dutta, S; Krause, A; Vosberg, S; Herold, T; Ksienzyk, B; Quintanilla-Martinez, L; Tizazu, B; Chopra, M; Graf, A; Krebs, S; Blum, H; Greif, P A; Vetter, A; Metzeler, K; Rothenberg-Thurley, M; Schneider, M R; Dahlhoff, M; Spiekermann, K; Zimber-Strobl, U; Wolf, E; Bohlander, S K

    2016-05-01

    The CALM/AF10 fusion gene is found in various hematological malignancies including acute myeloid leukemia (AML), T-cell acute lymphoblastic leukemia and malignant lymphoma. We have previously identified the leukemia stem cell (LSC) in a CALM/AF10-driven murine bone marrow transplant AML model as B220+ lymphoid cells with B-cell characteristics. To identify the target cell for leukemic transformation or 'cell of origin of leukemia' (COL) in non-disturbed steady-state hematopoiesis, we inserted the CALM/AF10 fusion gene preceded by a loxP-flanked transcriptional stop cassette into the Rosa26 locus. Vav-Cre-induced panhematopoietic expression of the CALM/AF10 fusion gene led to acute leukemia with a median latency of 12 months. Mice expressing CALM/AF10 in the B-lymphoid compartment using Mb1-Cre or CD19-Cre inducer lines did not develop leukemia. Leukemias had a predominantly myeloid phenotype but showed coexpression of the B-cell marker B220, and had clonal B-cell receptor rearrangements. Using whole-exome sequencing, we identified an average of two to three additional mutations per leukemia, including activating mutations in known oncogenes such as FLT3 and PTPN11. Our results show that the COL for CALM/AF10 leukemia is a stem or early progenitor cell and not a cell of B-cell lineage with a phenotype similar to that of the LSC in CALM/AF10+ leukemia. PMID:26686248

  1. Critical kinetic control of non-stoichiometric intermediate phase transformation for efficient perovskite solar cells.

    Science.gov (United States)

    Rong, Yaoguang; Venkatesan, Swaminathan; Guo, Rui; Wang, Yanan; Bao, Jiming; Li, Wenzhi; Fan, Zhiyong; Yao, Yan

    2016-07-14

    Organometal trihalide perovskites (OTP) have attracted significant attention as a low-cost and high-efficiency solar cell material. Due to the strong coordination between lead iodide (PbI2) and dimethyl sulfoxide (DMSO) solvent, a non-stoichiometric intermediate phase of MA2Pb3I8(DMSO)2 (MA = CH3NH3(+)) usually forms in the one-step deposition method that plays a critical role in attaining high power conversion efficiency. However, the kinetic understanding of how the non-stoichiometric intermediate phase transforms during thermal annealing is currently absent. In this work, we investigated such a phase transformation and provided a clear picture of three phase transition pathways as a function of annealing conditions. The interdiffusion of MAI and DMSO varies strongly with the annealing temperature and time, thus determining the final film composition and morphology. A surprising finding reveals that the best performing cells contain ∼18% of the non-stoichiometric intermediate phase, instead of pure phase OTP. The presence of such an intermediate phase enables smooth surface morphology and enhances the charge carrier lifetime. Our results highlight the importance of the intermediate phase growth kinetics that could lead to large-scale production of efficient solution processed perovskite solar cells. PMID:26890121

  2. MSH3-deficiency initiates EMAST without oncogenic transformation of human colon epithelial cells.

    Directory of Open Access Journals (Sweden)

    Christoph Campregher

    Full Text Available BACKGROUND/AIM: Elevated microsatellite instability at selected tetranucleotide repeats (EMAST is a genetic signature in certain cases of sporadic colorectal cancer and has been linked to MSH3-deficiency. It is currently controversial whether EMAST is associated with oncogenic properties in humans, specifically as cancer development in Msh3-deficient mice is not enhanced. However, a mutator phenotype is different between species as the genetic positions of repetitive sequences are not conserved. Here we studied the molecular effects of human MSH3-deficiency. METHODS: HCT116 and HCT116+chr3 (both MSH3-deficient and primary human colon epithelial cells (HCEC, MSH3-wildtype were stably transfected with an EGFP-based reporter plasmid for the detection of frameshift mutations within an [AAAG]17 repeat. MSH3 was silenced by shRNA and changes in protein expression were analyzed by shotgun proteomics. Colony forming assay was used to determine oncogenic transformation and double strand breaks (DSBs were assessed by Comet assay. RESULTS: Despite differential MLH1 expression, both HCT116 and HCT116+chr3 cells displayed comparable high mutation rates (about 4×10(-4 at [AAAG]17 repeats. Silencing of MSH3 in HCECs leads to a remarkable increased frameshift mutations in [AAAG]17 repeats whereas [CA]13 repeats were less affected. Upon MSH3-silencing, significant changes in the expression of 202 proteins were detected. Pathway analysis revealed overexpression of proteins involved in double strand break repair (MRE11 and RAD50, apoptosis, L1 recycling, and repression of proteins involved in metabolism, tRNA aminoacylation, and gene expression. MSH3-silencing did not induce oncogenic transformation and DSBs increased 2-fold. CONCLUSIONS: MSH3-deficiency in human colon epithelial cells results in EMAST, formation of DSBs and significant changes of the proteome but lacks oncogenic transformation. Thus, MSH3-deficiency alone is unlikely to drive human colon

  3. Transformation and tumor promoter sensitive phosphoproteins in JB-6 mouse epidermal cells: one is also sensitive to heat stress.

    Science.gov (United States)

    Gindhart, T D; Stevens, L; Copley, M P

    1984-09-01

    JB-6 mouse epidermal cells undergo irreversible transformation when exposed to tumor-promoting agents such as 12-O-tetradecanoyl-phorbol-13-acetate (TPA). Phosphoprotein changes related to transformation were sought in four tumor cell lines related to JB-6 cells. Two dimensional polyacrylamide gel electrophoresis showed altered abundances of five phosphoproteins in the tumor cell lines compared with five untransformed clones. The mol. wt. in Kilodaltons and isoelectric points in pH units were: 120/6.0, 80/4.5, 55/6.5, 37/5.0 and 23-25/4.5. In all four transformants pp80 was markedly decreased and the pp23-25 doublet increased. In two of the four transformants pp120 and pp55 were increased and pp37 decreased. Treatment of untransformed clones with TPA affected only one of the phosphoproteins altered in the transformants. Treatment of untransformed clones with TPA produced a 2-fold increase in pp80 after 5 h. pp80 returned to baseline levels by 24 h and changed little in the continuous presence of TPA for up to 96 h. The increase in pp80 with short term TPA treatment occurred in all of the untransformed clones but none of four transformants. Late preneoplastic (P+) JB-6 cells only require treatment with a tumor promoter to transform. Early preneoplastic (P-) JB-6 cells require prior transfection of DNA from late preneoplastic JB-6 cells to transform in response to tumor promoter treatment. Quantitative analysis of pp80 in early preneoplastic, late preneoplastic, and tumor cell lines showed an inverse relationship between the level of pp80 and degree of preneoplastic progression in these cells. pp80 represents approximately 2% of total cellular phosphoprotein in JB-6 cells, shows microheterogeneity of both mol. wt. and isoelectric point, occurs in the particulate fraction of cells and is readily solubilized by 1% Triton. pp80 is increased by heat stress and shares other properties with the recently described mammalian heat stress protein, hsp 80. pp80's decrease in

  4. Application of the inter-line PCR for the analyse of genomic rearrangements in radiation-transformed mammalian cell lines

    International Nuclear Information System (INIS)

    Repetitive DNA sequences of the LINE-family (long interspersed elements) that are widely distributed among the mammalian genome can be activated or altered by the exposure to ionizing radiation [1]. By the integration at new sites in the genome alterations in the expression of genes that are involved in cell transformation and/or carcinogenesis may occur [2, 3]. A new technique -the inter-LINE PCR - has been developed in order to detect and analyse such genomic rearrangements in radiation-transformed cell lines. From the sites of transformation- or tumour-specific changes in the genome it might be possible to develop new tumour markers for diagnostic purpose. (orig.)

  5. Transformation of intestinal stem cells into gastric stem cells on loss of transcription factor Cdx2

    NARCIS (Netherlands)

    Simmini, Salvatore; Bialecka, Monika; Huch, Meritxell; Kester, Lennart; van de Wetering, Marc; Sato, Toshiro; Beck, Felix; van Oudenaarden, Alexander; Clevers, Hans; Deschamps, Jacqueline

    2014-01-01

    The endodermal lining of the adult gastro-intestinal tract harbours stem cells that are responsible for the day-to-day regeneration of the epithelium. Stem cells residing in the pyloric glands of the stomach and in the small intestinal crypts differ in their differentiation programme and in the gene

  6. Transforming Growth Factor β Drives Hemogenic Endothelium Programming and the Transition to Hematopoietic Stem Cells.

    Science.gov (United States)

    Monteiro, Rui; Pinheiro, Philip; Joseph, Nicola; Peterkin, Tessa; Koth, Jana; Repapi, Emmanouela; Bonkhofer, Florian; Kirmizitas, Arif; Patient, Roger

    2016-08-22

    Hematopoietic stem cells (HSCs) are self-renewing multipotent stem cells that generate mature blood lineages throughout life. They, together with hematopoietic progenitor cells (collectively known as HSPCs), emerge from hemogenic endothelium in the floor of the embryonic dorsal aorta by an endothelial-to-hematopoietic transition (EHT). Here we demonstrate that transforming growth factor β (TGFβ) is required for HSPC specification and that it regulates the expression of the Notch ligand Jagged1a in endothelial cells prior to EHT, in a striking parallel with the epithelial-to-mesenchymal transition (EMT). The requirement for TGFβ is two fold and sequential: autocrine via Tgfβ1a and Tgfβ1b produced in the endothelial cells themselves, followed by a paracrine input of Tgfβ3 from the notochord, suggesting that the former programs the hemogenic endothelium and the latter drives EHT. Our findings have important implications for the generation of HSPCs from pluripotent cells in vitro. PMID:27499523

  7. Identification of Contaminated Cells with Viruses, Bacteria, or Fungi by Fourier Transform Infrared Microspectroscopy

    Directory of Open Access Journals (Sweden)

    V. Erukhimovitch

    2013-01-01

    Full Text Available Fourier transform infrared microspectroscopy (FTIR-M can detect small molecular changes in cells and therefore was previously applied for the identification of different biological samples. In the present study, FTIR spectroscopy was used for the identification and discrimination of Vero cells infected with herpes viruses or contaminated with bacteria or fungi in cell culture. Vero cells in culture were infected herpes simplex virus type 1 (HSV-1 or contaminated with E. coli bacteria or Candida albicans fungi and analyzed by FTIR microscopy at 24 h postinfection/contamination. Specific different spectral changes were observed according to the infecting or contaminating agent. For instance, both pure fungi and cell culture contaminated with this fungi showed specific peaks at 1030 cm−1 and at 1373 cm−1 regions, while pure E. coli and cell culture contaminated with this bacteria showed a specific and unique peak at 1657 cm−1. These results support the potential of developing FTIR microspectroscopy as a simple, reagent free method for identification and discrimination between different tissue infection or contamination with various pathogens.

  8. Outcome determinants for Transformed Indolent Lymphomas treated with or without Autologous Stem Cell Transplantation

    DEFF Research Database (Denmark)

    Madsen, C; Pedersen, M B; Vase, M Ø;

    2015-01-01

    of autologous stem-cell transplantation (ASCT) is still debated. The purpose of this study was to determine whether the outcome of TIL patients improved if they, at transformation, also received ASCT. Furthermore, we investigated the outcome of cases with histologically low- and high-grade components diagnosed......%; P = 0.07; PFS 53% versus 6%; P = 0.002), regardless of prior rituximab therapy. The beneficial effect of ASCT was significantly higher in patients who had not received rituximab at IL stage. CONCLUSIONS: ASCT improved the outcome in sequential, but not composite/discordant TIL. The beneficial impact...

  9. Expression of Transforming Growth Factor-β in Cultured Normal Human Lens Epithelia Cells

    Institute of Scientific and Technical Information of China (English)

    黄渝侃; 魏厚仁

    2004-01-01

    Summary: In order to investigate whether cultured normal human lens epithelial cells (LEC) express transforming growth factor β (TGF-β), reverse transcriptase polymerase chain reaction (RTPCR) and immunohistochemical methods were used for detection of TGF-β mRNA and protein in cultured normal human LEC. The results showed that a single RT-PCR amplified product about 310bp was obtained, and the sequence was homologous to the known sequence. TGF-β immunostain was positive in the plasma of LEC. It was suggested that normal human LEC could produce TGF-β, and LEC could be affected by TGF-β through autocrine action.

  10. Effects of 5-azacytidine on the progressive nature of cell transformation.

    OpenAIRE

    Hsiao, W L; Gattoni-Celli, S; Weinstein, I B

    1985-01-01

    C3H 10T1/2 mouse embryo fibroblasts were exposed to 3 microM 5-azacytidine for 24 h and then serially passaged in the absence of 5-azacytidine and examined for subsequent changes in growth properties. The treated cells showed changes in morphology, saturation density, growth rate, and serum dependence. By the 5th passage they acquired the ability to grow in 0.3% agarose, and by the 30th passage they gave rise to fully transformed foci that grew in agarose, in agar, and in liquid suspension. T...

  11. Genetic assignment of multiple E2 gene products in bovine papillomavirus-transformed cells.

    OpenAIRE

    Lambert, P F; Hubbert, N L; Howley, P M; Schiller, J T

    1989-01-01

    The E2 open reading frame of bovine papillomavirus type 1 has been shown genetically to encode at least three transcriptional regulatory factors, and three E2 specific proteins have been recently identified in virally transformed rodent cells. In this study, the genes encoding these E2 specific proteins have been determined. The 48-kilodalton (kDa) protein was identified as the product of a full-length E2 open reading frame cDNA, which confirmed that this polypeptide is the E2 transactivator....

  12. Acinar Cell Cyst adenoma (Acinar Cystic Transformation) of the Pancreas: the Radiologic-Pathologic Features

    Energy Technology Data Exchange (ETDEWEB)

    Gumus, Mehmet; Algin, Oktay; Gundogdu, Haldun [Ataturk Training and Research Hospital, Ankara (Turkmenistan); Ugras, Serdar [Selcuk University, Selcuklu Medical Faculty, Konya (Turkmenistan)

    2011-02-15

    Acinar cystic transformation of the pancreas is also known as acinar cell cystadenoma (ACC), and this is an extremely rare benign lesion that was first described in April 2002. We report here on a case of a previously asymptomatic patient with pancreatic ACC and this was diagnosed by computed tomography (CT) and magnetic resonance imaging (MRI). To the best of our knowledge, there is no previous report concerning the CT or MRI features of ACC in the medical literature. We present here the CT, MRI and pathological findings of pancreatic ACC

  13. Improvement of the BALB/c-3T3 cell transformation assay: a tool for investigating cancer mechanisms and therapies.

    Science.gov (United States)

    Poburski, Doerte; Thierbach, René

    2016-01-01

    The identification of cancer preventive or therapeutic substances as well as carcinogenic risk assessment of chemicals is nowadays mostly dependent on animal studies. In vitro cell transformation assays mimic different stages of the in vivo neoplastic process and represent an excellent alternative to study carcinogenesis and therapeutic options. In the BALB/c-3T3 two-stage transformation assay cells are chemically transformed by treatment with MCA and TPA, along with the final Giemsa staining of morphological aberrant foci. In addition to the standard method we can show, that it is possible to apply other chemicals in parallel to identify potential preventive or therapeutic substances during the transformation process. Furthermore, we successfully combined the BALB/c cell transformation assay with several endpoint applications for protein analysis (immunoblot, subcellular fractionation and immunofluorescence) or energy parameter measurements (glucose and oxygen consumption) to elucidate cancer mechanisms in more detail. In our opinion the BALB/c cell transformation assay proves to be an excellent model to investigate alterations in key proteins or energy parameters during the different stages of transformation as well as therapeutic substances and their mode of action.

  14. Improvement of the BALB/c-3T3 cell transformation assay: a tool for investigating cancer mechanisms and therapies

    Science.gov (United States)

    Poburski, Doerte; Thierbach, René

    2016-01-01

    The identification of cancer preventive or therapeutic substances as well as carcinogenic risk assessment of chemicals is nowadays mostly dependent on animal studies. In vitro cell transformation assays mimic different stages of the in vivo neoplastic process and represent an excellent alternative to study carcinogenesis and therapeutic options. In the BALB/c-3T3 two-stage transformation assay cells are chemically transformed by treatment with MCA and TPA, along with the final Giemsa staining of morphological aberrant foci. In addition to the standard method we can show, that it is possible to apply other chemicals in parallel to identify potential preventive or therapeutic substances during the transformation process. Furthermore, we successfully combined the BALB/c cell transformation assay with several endpoint applications for protein analysis (immunoblot, subcellular fractionation and immunofluorescence) or energy parameter measurements (glucose and oxygen consumption) to elucidate cancer mechanisms in more detail. In our opinion the BALB/c cell transformation assay proves to be an excellent model to investigate alterations in key proteins or energy parameters during the different stages of transformation as well as therapeutic substances and their mode of action. PMID:27611302

  15. Improvement of the BALB/c-3T3 cell transformation assay: a tool for investigating cancer mechanisms and therapies.

    Science.gov (United States)

    Poburski, Doerte; Thierbach, René

    2016-01-01

    The identification of cancer preventive or therapeutic substances as well as carcinogenic risk assessment of chemicals is nowadays mostly dependent on animal studies. In vitro cell transformation assays mimic different stages of the in vivo neoplastic process and represent an excellent alternative to study carcinogenesis and therapeutic options. In the BALB/c-3T3 two-stage transformation assay cells are chemically transformed by treatment with MCA and TPA, along with the final Giemsa staining of morphological aberrant foci. In addition to the standard method we can show, that it is possible to apply other chemicals in parallel to identify potential preventive or therapeutic substances during the transformation process. Furthermore, we successfully combined the BALB/c cell transformation assay with several endpoint applications for protein analysis (immunoblot, subcellular fractionation and immunofluorescence) or energy parameter measurements (glucose and oxygen consumption) to elucidate cancer mechanisms in more detail. In our opinion the BALB/c cell transformation assay proves to be an excellent model to investigate alterations in key proteins or energy parameters during the different stages of transformation as well as therapeutic substances and their mode of action. PMID:27611302

  16. Genotoxic and cytostatic effects of 6-pentadecyl salicylic anacardic acid in transformed cell lines and peripheral blood mononuclear cells.

    Science.gov (United States)

    Alam-Escamilla, David; Estrada-Muñiz, Elizabet; Solís-Villegas, Erik; Elizondo, Guillermo; Vega, Libia

    2015-01-01

    In Mexico, as in many other countries, traditional medicine is used for the treatment of several diseases. In particular, Amphipterygium adstringens infusion is used for gastritis, gastric ulcers, and gastric cancer. Extracts from this tree have microbicidal effects against Helicobacter pylori, an important risk factor for gastric cancer development. Anacardic acids are constituents of A. adstringens, and 6-pentadecyl salicylic acid (6-PSA) is the most abundant. However, there is a lack of information regarding the effects of 6-PSA on cancer cells. Therefore, we investigated whether 6-PSA has differential effects on the induction of genotoxicity, cytostaticity, and apoptosis in normal human peripheral blood mononucleated cells (PBMCs), bone marrow polychromatic erythrocytes of Balb/c mice, and human transformed cell lines derived from both gastric cancer (AGS cells) and leukaemia (K562 cells). Treatment with 6-PSA (30-150 μM) reduced the viability of AGS and K562 cells together with a moderate, but significant, increase in the frequency of micronucleated cells and the induction of DNA breakage (Comet Assay). Moreover, 6-PSA increased the apoptosis rate in both the AGS and K562 cell lines in a caspase 8-dependent manner. In contrast, neither cytotoxicity nor genotoxicity were observed in PBMCs or bone marrow polychromatic erythrocytes of Balb/c mice after treatment with low doses of 6-PSA (0.2-2.0 mg/Kg). Instead, 6-PSA treatment resulted in the inhibition of PBMC proliferation, which was reversible after the compound was removed. Additionally, 6-PSA treatments (2-20 mg/Kg) increased the frequency of mature polychromatic erythrocytes in the bone marrow, suggesting a possible effect on the differentiation process of immune cells. The present results indicate that 6-PSA induces cytotoxicity and moderate genotoxicity, together with an increase in the apoptosis rate, in a caspase 8-dependent manner in gastric cancer cells. In contrast, a low toxicity was observed when

  17. Transforming potential and matrix stiffness co-regulate confinement sensitivity of tumor cell migration

    Science.gov (United States)

    Pathak, Amit

    2013-01-01

    It is now well established that tumor cell invasion through tissue is strongly regulated by the microstructural and mechanical properties of the extracellular matrix (ECM). However, it remains unclear how these physical microenvironmental inputs are jointly processed with oncogenic lesions to drive invasion. In this study, we address this open question by combining a microfabricated polyacrylamide channel (μPAC) platform that enables independent control of ECM stiffness and confinement with an isogenically-matched breast tumor progression series in which the oncogenes ErbB2 and 14-3-3ζ are overexpressed independently or in tandem. We find that increasing channel confinement and overexpressing ErbB2 both promote cell migration to a similar degree when other parameters are kept constant. In contrast, 14-3-3ζ overexpression slows migration speed, and does so in a fashion that dwarfs effects of ECM confinement and stiffness. We also find that ECM stiffness dramatically enhances cell motility when combined with ErbB2 overexpression, demonstrating that biophysical cues and cell-intrinsic parameters promote cell invasion in an integrative manner. Morphometric analysis of cells inside the μPAC platform reveals that the rapid cell migration induced by narrow channels and ErbB2 overexpression both are accompanied by increased cell polarization. Disruption of this polarization by pharmacological inhibition of Rac GTPase phenocopies 14-3-3ζ overexpression by reducing cell polarization and slowing migration. By systematically measuring migration speed as a function of matrix stiffness and confinement, we also quantify for the first time the sensitivity of migration speed to microchannel properties and transforming potential. These results demonstrate that oncogenic lesions and ECM biophysical properties can synergistically interact to drive invasive migration, and that both inputs may act through common molecular mechanisms to enhance migration speed. PMID:23832051

  18. Kaposi's sarcoma herpesvirus microRNAs induce metabolic transformation of infected cells.

    Directory of Open Access Journals (Sweden)

    Ohad Yogev

    2014-09-01

    Full Text Available Altered cell metabolism is inherently connected with pathological conditions including cancer and viral infections. Kaposi's sarcoma-associated herpesvirus (KSHV is the etiological agent of Kaposi's sarcoma (KS. KS tumour cells display features of lymphatic endothelial differentiation and in their vast majority are latently infected with KSHV, while a small number are lytically infected, producing virions. Latently infected cells express only a subset of viral genes, mainly located within the latency-associated region, among them 12 microRNAs. Notably, the metabolic properties of KSHV-infected cells closely resemble the metabolic hallmarks of cancer cells. However, how and why KSHV alters host cell metabolism remains poorly understood. Here, we investigated the effect of KSHV infection on the metabolic profile of primary dermal microvascular lymphatic endothelial cells (LEC and the functional relevance of this effect. We found that the KSHV microRNAs within the oncogenic cluster collaborate to decrease mitochondria biogenesis and to induce aerobic glycolysis in infected cells. KSHV microRNAs expression decreases oxygen consumption, increase lactate secretion and glucose uptake, stabilize HIF1α and decreases mitochondria copy number. Importantly this metabolic shift is important for latency maintenance and provides a growth advantage. Mechanistically we show that KSHV alters host cell energy metabolism through microRNA-mediated down regulation of EGLN2 and HSPA9. Our data suggest that the KSHV microRNAs induce a metabolic transformation by concurrent regulation of two independent pathways; transcriptional reprograming via HIF1 activation and reduction of mitochondria biogenesis through down regulation of the mitochondrial import machinery. These findings implicate viral microRNAs in the regulation of the cellular metabolism and highlight new potential avenues to inhibit viral latency.

  19. Comparison of heat and radiation sensitivity in normal C3H-10T1/2 cells and cells transformed by radiation or the H ras oncogene

    International Nuclear Information System (INIS)

    C/sub 3/H 10T1/2 cells were transformed from the normal to the malignant state using X-rays or by transfection with a plasmid containing the active H ras oncogene. Clones of cells with a transformed morphology were isolated and grown into large populations. These cells were tested and produced tumors in C/sub 3/H mice. Seven clones transformed by radiation showed a range of sensitivity to heat and X-rays that varied from greater to lesser than the heat and X-ray sensitivity in normal cells. Similar results were observed for the cells transformed by the H ras oncogene. Thus, the malignant transformation of C/sub 3/H 10T1/2 cells by X-rays or H ras oncogenes did not, in general result in increased thermal sensitivity, implying that the malignant phenotype is not intrinsically more heat sensitive than the normal cell. The thermal sensitivity in the various transformed cell lines was not correlated with membrane cholesterol or phospholipid content

  20. Chest HRCT findings in acute transformation of adult T-cell lymphoma/leukemia

    International Nuclear Information System (INIS)

    To assess chest high-resolution computed tomography (HRCT) findings in patients with acute transformation of adult T cell leukaemia/lymphoma (ATLL). We retrospectively identified 72 consecutive patients at our institution with ATLL between October 2000 and March 2014. The cases included acute type (n = 20), lymphoma type (n = 21), smouldering type (n = 24) and chronic type (n = 7). Sixteen (7 men, 9 women; aged 36-85 years, mean 63.3 years) of 31 patients (24 with smouldering and seven with chronic type; 51.6 %) developed acute transformation of ATLL, and had undergone chest HRCT examinations. Parenchymal abnormalities, enlarged lymph nodes, pericardial effusion, pleural effusion and skin lesions were evaluated on HRCT. Chest HRCT of 15 of the 16 patients showed abnormal findings, including ground-glass opacity (GGO) (n = 8), consolidation (n = 5), interlobular septal thickening (n = 5) and nodules (n = 5). Pleural effusion was found in five patients, lymph node enlargement in 10 patients and multiple skin thickening in two patients. Almost all patients with acute transformation of ATLL had abnormal findings on chest HRCT, which consisted mainly of lymph node enlargement, GGO, interlobular septal thickening, nodules and bilateral pleural effusions. (orig.)

  1. Chest HRCT findings in acute transformation of adult T-cell lymphoma/leukemia

    Energy Technology Data Exchange (ETDEWEB)

    Okada, Fumito; Sato, Haruka; Omeri, Ahmad Khalid; Ono, Asami; Tokuyama, Kouhei; Ando, Yumiko; Matsumoto, Akira; Mori, Hiromu [Oita University Faculty of Medicine, Department of Radiology, Yufu, Oita (Japan); Ogata, Masao; Kohno, Kazuhiro; Takano, Kuniko [Oita University Faculty of Medicine, Department of Medical Oncology and Hematology, Yufu, Oita (Japan)

    2015-06-01

    To assess chest high-resolution computed tomography (HRCT) findings in patients with acute transformation of adult T cell leukaemia/lymphoma (ATLL). We retrospectively identified 72 consecutive patients at our institution with ATLL between October 2000 and March 2014. The cases included acute type (n = 20), lymphoma type (n = 21), smouldering type (n = 24) and chronic type (n = 7). Sixteen (7 men, 9 women; aged 36-85 years, mean 63.3 years) of 31 patients (24 with smouldering and seven with chronic type; 51.6 %) developed acute transformation of ATLL, and had undergone chest HRCT examinations. Parenchymal abnormalities, enlarged lymph nodes, pericardial effusion, pleural effusion and skin lesions were evaluated on HRCT. Chest HRCT of 15 of the 16 patients showed abnormal findings, including ground-glass opacity (GGO) (n = 8), consolidation (n = 5), interlobular septal thickening (n = 5) and nodules (n = 5). Pleural effusion was found in five patients, lymph node enlargement in 10 patients and multiple skin thickening in two patients. Almost all patients with acute transformation of ATLL had abnormal findings on chest HRCT, which consisted mainly of lymph node enlargement, GGO, interlobular septal thickening, nodules and bilateral pleural effusions. (orig.)

  2. GST-π EXPRESSION IN TRANSFORMED CELLS BY TRANSFECTING OF DNA ISOLATED FROM HUMAN FETAL LUNG TISSUES TREATED WITH CARCINOGENS

    Institute of Scientific and Technical Information of China (English)

    Yao Denggao; Hu Guogang; Luo Xianmao; Zhu Ming

    1998-01-01

    Objective: To investigate the relationship between the GSTs, GST-π expression and initiation of lung carcinogenesis. Methods: The Rat-1 cells were transformed by carcinogens (DEN, MNU and CSC) treated fetal lung DNA for 24 h. Results: The GSTs activities toward 1-chloro-2, 4-dinitro-benzene (CDNB) in transformed cells were significantly higher than in the solvent control cells (P<0.05). GST-π content and GST-π mRNA expression level of transformed cells were also higher than those of control cells which were performed by ELISA and Northern blotting method respectively. The results indicated that the higher GSTS activities of transformed cells were due to the increase of GST-π content and the GST-π mRNA overexpressing may be responsible for the increase of GST-π protein level of the transformed cells. Conclusion: The changes of GSTs and GST-π may be considered as the one of the biomarkers of the initiation of human lung carcinogenesis.

  3. Marek's disease virus Meq transforms chicken cells via the v-Jun transcriptional cascade: A converging transforming pathway for avian oncoviruses

    OpenAIRE

    Levy, Alon M.; Gilad, Oren; Xia, Liang; Izumiya, Yoshihiro; Choi, Jonathan; Tsalenko, Anya; Yakhini, Zohar; Witter, Richard; Lee, Lucy; Cardona, Carol J.; Kung, Hsing-Jien

    2005-01-01

    Marek's disease virus (MDV) is a highly pathogenic and oncogenic herpesvirus of chickens. MDV encodes a basic leucine zipper (bZIP) protein, Meq (MDV EcoQ). The bZIP domain of Meq shares homology with Jun/Fos, whereas the transactivation/repressor domain is entirely different. Increasing evidence suggests that Meq is the oncoprotein of MDV. Direct evidence that Meq transforms chicken cells and the underlying mechanism, however, remain completely unknown. Taking advantage of the DF-1 chicken e...

  4. Endogenous APOBEC3B restricts LINE-1 retrotransposition in transformed cells and human embryonic stem cells.

    Science.gov (United States)

    Wissing, Silke; Montano, Mauricio; Garcia-Perez, Jose Luis; Moran, John V; Greene, Warner C

    2011-10-21

    Members of the APOBEC3 (A3) family of cytidine deaminase enzymes act as host defense mechanisms limiting both infections by exogenous retroviruses and mobilization of endogenous retrotransposons. Previous studies revealed that the overexpression of some A3 proteins could restrict engineered human Long INterspersed Element-1 (LINE-1 or L1) retrotransposition in HeLa cells. However, whether endogenous A3 proteins play a role in restricting L1 retrotransposition remains largely unexplored. Here, we show that HeLa cells express endogenous A3B and A3C, whereas human embryonic stem cells (hESCs) express A3B, A3C, A3DE, A3F, and A3G. To study the relative contribution of endogenous A3 proteins in restricting L1 retrotransposition, we first generated small hairpin RNAs (shRNAs) to suppress endogenous A3 mRNA expression, and then assessed L1 mobility using a cell-based L1 retrotransposition assay. We demonstrate that in both HeLa and hESCs, shRNA-based knockdown of A3B promotes a ∼2-3.7-fold increase in the retrotransposition efficiency of an engineered human L1. Knockdown of the other A3s produced no significant increase in L1 activity. Thus, A3B appears to restrict engineered L1 retrotransposition in a broad range of cell types, including pluripotent cells.

  5. Speciation and transformations of cobalt(II) in bacterial cells using emission (57Co) Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Complete text of publication follows. The 57Co emission variant of Moessbauer spectroscopy (EMS), despite its solitary applications in biology owing to intrinsic methodological difficulties (Yu.D. Perfiliev, A.A. Kamnev, Moessbauer Effect Ref. and Data J., 30 (2007) 121-122; A.A. Kamnev, J. Mol. Struct., 744-747 (2005) 161-167), is highly sensitive and informative. The parameters of 57Co emission spectra provide chemical speciation data for the 57Co cation (chemical state, coordination environment and symmetry, etc.), as well as quantitative information on its distribution between different cation-binding sites in complicated biosystems (A.A. Kamnev, in 'Metal Ions in Biology and Medicine', Vol. 10, John Libbey Eurotext, Paris (2008), pp. 522-527). 57Co EMS can be successfully applied for monitoring 57Co2+ interactions with microbial cells, including its metabolic transformations (A.A. Kamnev et al., Anal. Chim. Acta, 573-574 (2006) 445-452). Comparative studies in rapidly frozen aqueous suspensions of live and dead cells of the ubiquitous phytostimulating soil bacterium Azospirillum brasilense have shown similarities in the chemical species formed upon purely chemical interaction of 57Co2+ traces with dead cell biomass and those formed upon primary rapid steps (2 min) of 57Co2+ sorption by the surface of live cells. For live cells, however, the parameters of 57Co emission spectra were found to change within an hour, which reflected ongoing metabolic transformations of the cation. The data obtained are in good agreement with the recently discovered involvement of Co2+ in reactions with labile [Fe-S] clusters during their de novo biosynthesis or repair in E. coli (C. Ranquet et al., J. Biol. Chem., 282 (2007) 30442-30451), presenting the molecular basis for Co2+ toxicity, besides Co2+-induced oxidative stress. The results obtained show that 57Co EMS can provide unique information both for speciation bioanalysis and for the monitoring of radionuclide bioleaching and

  6. Effect of transforming growth factor-β1 on human intrahepatic cholangiocarcinoma cell growth

    Institute of Scientific and Technical Information of China (English)

    Tetsuya Shimizu; Takashi Tajiri; Shigeki Yokomuro; Yoshiaki Mizuguchi; Yutaka Kawahigashi; Yasuo Arima; Nobuhiko Taniai; Yasuhiro Mamada; Hiroshi Yoshida; Koho Akimaru

    2006-01-01

    AIM: To elucidate the biological effects of transforming growth factor-β1 (TGF-β1) on intrahepatic cholangiocarcinoma (ICC).METHODS: We investigated the effects of TGF-β1 on human ICC cell lines (HuCCT1, MEC, and HuH-28) by monitoring the influence of TGF-β1 on tumor growth and interleukin-6 (IL-6) expression in ICC cells.RESULTS: All three human ICC cell lines produced TGF-β1 and demonstrated accelerated growth in the presence of TGF-β1 with no apoptotic effect. Studies on HuCCT1 revealed a TGF-β1-induced stimulation of the expression of TGF-β1, as well as a decrease in TGF-β1 mRNA expression induced by neutralizing anti-TGF-β1 antibody. These results indicate that TGF-β1 stimulates the production and function of TGF-β1 in an autocrine fashion. Further, IL-6 secretion was observed in all three cell lines and exhibited an inhibitory response to neutralizing anti-TGF-β1 antibody. Experiments using HuCCT1 revealed a TGF-β1-induced acceleration of IL-6 protein expression and mRNA levels. These findings demonstrate a functional interaction between TGF-β1 and IL-6. All three cell lines proliferated in the presence of IL-6. In contrast, TGF-β1 induced no growth effect in HuCCT1 in the presence of small interfering RNA against a specific cell surface receptor of IL-6 and signal transducer and activator of transcription-3.CONCLUSION: ICC cells produce TGF-β1 and confer a TGF-β1-induced growth effect in an autocrine fashion.TGF-β1 activates IL-6 production, and the functional interaction between TGF-β1 and IL-6 contributes to ICC cell growth by TGF-β1.

  7. Transforming Growth Factor-β Signaling Guides the Differentiation of Innate Lymphoid Cells in Salivary Glands.

    Science.gov (United States)

    Cortez, Victor S; Cervantes-Barragan, Luisa; Robinette, Michelle L; Bando, Jennifer K; Wang, Yaming; Geiger, Theresa L; Gilfillan, Susan; Fuchs, Anja; Vivier, Eric; Sun, Joe C; Cella, Marina; Colonna, Marco

    2016-05-17

    The signals guiding differentiation of innate lymphoid cells (ILCs) within tissues are not well understood. Salivary gland (SG) ILCs as well as liver and intestinal intraepithelial ILC1 have markers that denote tissue residency and transforming growth factor-β (TGF-β) imprinting. We deleted Tgfbr2 in cells expressing the ILC and NK marker NKp46 and found that SG ILCs were reduced in number. They lost distinct tissue markers, such as CD49a, and the effector molecules TRAIL and CD73. Expression of the transcription factor Eomes, which promotes NK cell differentiation, was elevated. Conversely, Eomes deletion in NKp46(+) cells enhanced TGF-β-imprinting of SG ILCs. Thus, TGF-β induces SG ILC differentiation by suppressing Eomes. TGF-β acted through a JNK-dependent, Smad4-independent pathway. Transcriptome analysis demonstrated that SG ILCs had characteristic of both NK cells and ILC1. Finally, TGF-β imprinting of SG ILCs was synchronized with SG development, highlighting the impact of tissue microenvironment on ILC development. PMID:27156386

  8. Binary cell fate decisions and fate transformation in the Drosophila larval eye.

    Directory of Open Access Journals (Sweden)

    Abhishek Kumar Mishra

    Full Text Available The functionality of sensory neurons is defined by the expression of specific sensory receptor genes. During the development of the Drosophila larval eye, photoreceptor neurons (PRs make a binary choice to express either the blue-sensitive Rhodopsin 5 (Rh5 or the green-sensitive Rhodopsin 6 (Rh6. Later during metamorphosis, ecdysone signaling induces a cell fate and sensory receptor switch: Rh5-PRs are re-programmed to express Rh6 and become the eyelet, a small group of extraretinal PRs involved in circadian entrainment. However, the genetic and molecular mechanisms of how the binary cell fate decisions are made and switched remain poorly understood. We show that interplay of two transcription factors Senseless (Sens and Hazy control cell fate decisions, terminal differentiation of the larval eye and its transformation into eyelet. During initial differentiation, a pulse of Sens expression in primary precursors regulates their differentiation into Rh5-PRs and repression of an alternative Rh6-cell fate. Later, during the transformation of the larval eye into the adult eyelet, Sens serves as an anti-apoptotic factor in Rh5-PRs, which helps in promoting survival of Rh5-PRs during metamorphosis and is subsequently required for Rh6 expression. Comparably, during PR differentiation Hazy functions in initiation and maintenance of rhodopsin expression. Hazy represses Sens specifically in the Rh6-PRs, allowing them to die during metamorphosis. Our findings show that the same transcription factors regulate diverse aspects of larval and adult PR development at different stages and in a context-dependent manner.

  9. Involvement of HIF-2α-mediated inflammation in arsenite-induced transformation of human bronchial epithelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Yuan; Zhao, Yue; Xu, Wenchao; Luo, Fei; Wang, Bairu; Li, Yuan; Pang, Ying; Liu, Qizhan, E-mail: drqzliu@hotmail.com

    2013-10-15

    Arsenic is a well established human carcinogen that causes diseases of the lung. Some studies have suggested a link between inflammation and lung cancer; however, it is unknown if arsenite-induced inflammation causally contributes to arsenite-caused malignant transformation of cells. In this study, we investigated the molecular mechanisms underlying inflammation during neoplastic transformation induced in human bronchial epithelial (HBE) cells by chronic exposure to arsenite. The results showed that, on acute or chronic exposure to arsenite, HBE cells over-expressed the pro-inflammatory cytokines, interleukin-6 (IL-6), interleukin-8 (IL-8), and interleukin-1β (IL-1β). The data also indicated that HIF-2α was involved in arsenite-induced inflammation. Moreover, IL-6 and IL-8 were essential for the malignant progression of arsenite-transformed HBE cells. Thus, these experiments show that HIF-2α mediates arsenite-induced inflammation and that such inflammation is involved in arsenite-induced malignant transformation of HBE cells. The results provide a link between the inflammatory response and the acquisition of a malignant transformed phenotype by cells chronically exposed to arsenite and thus establish a previously unknown mechanism for arsenite-induced carcinogenesis. - Highlights: • Arsenite induces inflammation. • Arsenite-induced the increases of IL-6 and IL-8 via HIF-2α. • Inflammation is involved in arsenite-induced carcinogenesis.

  10. Relation of spontaneous transformation in cell culture to adaptive growth and clonal heterogeneity.

    Science.gov (United States)

    Rubin, A L; Yao, A; Rubin, H

    1990-01-01

    Cell transformation in culture is marked by the appearance of morphologically altered cells that continue to multiply to form discrete foci in confluent sheets when the surrounding cells are inhibited. These foci occur spontaneously in early-passage NIH 3T3 cells grown to confluency in 10% calf serum (CS) but are not seen in cultures grown to confluency in 2% CS. However, repeated passage of the cells at low density in 2% CS gives rise to an adapted population that grows to increasingly higher saturation densities and produces large numbers of foci in 2% CS. The increased saturation density of the adapted population in 2% CS is retained upon repeated passage in 10% CS, but the number and size of the foci produced in 2% CS gradually decrease under this regime. Clonal analysis confirms that the focus-forming potential of most if not all of the cells in a population increases in response to a continuously applied growth constraint, although only a small fraction of the population may actually form foci in a given assay. The acquired capacity for focus formation varies widely in clones derived from the adapted population and changes in diverse ways upon further passage of the clones. We propose that the adaptive changes result from progressive selection of successive phenotypic variations in growth capacity that occur spontaneously. The process designated progressive state selection resolves the apparent dichotomy between spontaneous mutation with selection on the one hand and induction on the other, by introducing selection among fluctuating states or metabolic patterns rather than among genetically altered cells.

  11. Althaea rosea Cavanil and Plantago major L. suppress neoplastic cell transformation through the inhibition of epidermal growth factor receptor kinase.

    Science.gov (United States)

    Choi, Eun-Sun; Cho, Sung-Dae; Shin, Ji-Ae; Kwon, Ki Han; Cho, Nam-Pyo; Shim, Jung-Hyun

    2012-10-01

    For thousands of years in Asia, Althaea rosea Cavanil (ARC) and Plantago major L. (PML) have been used as powerful non-toxic therapeutic agents that inhibit inflammation. However, the anticancer mechanisms and molecular targets of ARC and PML are poorly understood, particularly in epidermal growth factor (EGF)-induced neoplastic cell transformation. The aim of this study was to evaluate the chemopreventive effects and mechanisms of the methanol extracts from ARC (MARC) and PML (MPML) in EGF-induced neoplastic cell transformation of JB6 P+ mouse epidermal cells using an MTS assay, anchorage-independent cell transformation assay and western blotting. Our results showed that MARC and MPML significantly suppressed neoplastic cell transformation by inhibiting the kinase activity of the EGF receptor (EGFR). The activation of EGFR by EGF was suppressed by MARC and MPML treatment in EGFR(+/+) cells, but not in EGFR(-/-) cells. In addition, MARC and MPML inhibited EGF-induced cell proliferation in EGFR-expressing murine embryonic fibroblasts (EGFR(+/+)). These results strongly indicate that EGFR targeting by MARC and MPML may be a good strategy for chemopreventive or chemotherapeutic applications.

  12. Althaea rosea Cavanil and Plantago major L. suppress neoplastic cell transformation through the inhibition of epidermal growth factor receptor kinase.

    Science.gov (United States)

    Choi, Eun-Sun; Cho, Sung-Dae; Shin, Ji-Ae; Kwon, Ki Han; Cho, Nam-Pyo; Shim, Jung-Hyun

    2012-10-01

    For thousands of years in Asia, Althaea rosea Cavanil (ARC) and Plantago major L. (PML) have been used as powerful non-toxic therapeutic agents that inhibit inflammation. However, the anticancer mechanisms and molecular targets of ARC and PML are poorly understood, particularly in epidermal growth factor (EGF)-induced neoplastic cell transformation. The aim of this study was to evaluate the chemopreventive effects and mechanisms of the methanol extracts from ARC (MARC) and PML (MPML) in EGF-induced neoplastic cell transformation of JB6 P+ mouse epidermal cells using an MTS assay, anchorage-independent cell transformation assay and western blotting. Our results showed that MARC and MPML significantly suppressed neoplastic cell transformation by inhibiting the kinase activity of the EGF receptor (EGFR). The activation of EGFR by EGF was suppressed by MARC and MPML treatment in EGFR(+/+) cells, but not in EGFR(-/-) cells. In addition, MARC and MPML inhibited EGF-induced cell proliferation in EGFR-expressing murine embryonic fibroblasts (EGFR(+/+)). These results strongly indicate that EGFR targeting by MARC and MPML may be a good strategy for chemopreventive or chemotherapeutic applications. PMID:22767187

  13. Transforming growth factor-beta inhibits human antigen-specific CD4(+) T cell proliferation without modulating the cytokine response

    NARCIS (Netherlands)

    Tiemessen, MM; Kunzmann, S; Schmidt-Weber, CB; Garssen, J; Bruijnzeel-Koomen, CAFM; Knol, EF; Van Hoffen, E

    2003-01-01

    Transforming growth factor (TGF)-beta has been demonstrated to play a key role in the regulation of the immune response, mainly by its suppressive function towards cells of the immune system. In humans, the effect of TGF-beta on antigen-specific established memory T cells has not been investigated y

  14. TDAG51 is an ERK signaling target that opposes ERK-mediated HME16C mammary epithelial cell transformation

    Directory of Open Access Journals (Sweden)

    Ward Yvona

    2008-07-01

    Full Text Available Abstract Introduction Signaling downstream of Ras is mediated by three major pathways, Raf/ERK, phosphatidylinositol 3 kinase (PI3K, and Ral guanine nucleotide exchange factor (RalGEF. Ras signal transduction pathways play an important role in breast cancer progression, as evidenced by the frequent over-expression of the Ras-activating epidermal growth factor receptors EGFR and ErbB2. Here we investigated which signal transduction pathways downstream of Ras contribute to EGFR-dependent transformation of telomerase-immortalized mammary epithelial cells HME16C. Furthermore, we examined whether a highly transcriptionally regulated ERK pathway target, PHLDA1 (TDAG51, suggested to be a tumor suppressor in breast cancer and melanoma, might modulate the transformation process. Methods Cellular transformation of human mammary epithelial cells by downstream Ras signal transduction pathways was examined using anchorage-independent growth assays in the presence and absence of EGFR inhibition. TDAG51 protein expression was down-regulated by interfering small hairpin RNA (shRNA, and the effects on cell proliferation and death were examined in Ras pathway-transformed breast epithelial cells. Results Activation of both the ERK and PI3K signaling pathways was sufficient to induce cellular transformation, which was accompanied by up-regulation of EGFR ligands, suggesting autocrine EGFR stimulation during the transformation process. Only activation of the ERK pathway was sufficient to transform cells in the presence of EGFR inhibition and was sufficient for tumorigenesis in xenografts. Up-regulation of the PHLDA1 gene product, TDAG51, was found to correlate with persistent ERK activation and anchorage-independent growth in the absence or presence of EGFR inhibition. Knockdown of this putative breast cancer tumor-suppressor gene resulted in increased ERK pathway activation and enhanced matrix-detached cellular proliferation of Ras/Raf transformed cells. Conclusion

  15. Transformation of BALB/c 3T3 cells in vitro by the fungicides captan, captafol and folpet.

    Science.gov (United States)

    Perocco, P; Colacci, A; Del Ciello, C; Grilli, S

    1995-10-01

    Cytotoxic and cell-transforming activities of the three fungicides, captan, captafol and folpet, have been studied in an experimental in vitro model by exposing BALB/c 3T3 cells to the chemicals with or without S-9 mix-induced bioactivation. Cytotoxicity of the three compounds was reduced in the presence of the metabolizing system. Each assayed pesticide displayed cell-transforming ability in the presence of the metabolizing system. The relative efficiency was: captafol > captan > folpet. Cell transformation was considered to be due to carcinogenesis-promoting activity. These data, obtained in a medium-term (6-8 weeks) experimental model, contribute to a better understanding of the action of the three pesticides in the multistep carcinogenesis process and provide more information concerning the oncogenic risk of these xenobiotic compounds for humans.

  16. Fourier-transform infrared spectroscopy for rapid screening and live-cell monitoring: application to nanotoxicology

    Energy Technology Data Exchange (ETDEWEB)

    Sundaram, S. K.; Sacksteder, Colette A.; Weber, T. J.; Riley, Brian J.; Addleman, Raymond S.; Harrer, Bruce J.; Peterman, John W.

    2013-01-01

    A significant challenge to realize the full potential of nanotechnology for therapeutic and diagnostic applications is to understand and evaluate how live-cells interact with an external stimulus, e.g., a nanosized particle (NSP), and the toxicity and broad risk associated with these stimuli. NSPs are increasingly used in medicine with largely undetermined hazards in complex cell dynamics and environments. It is difficult to capture the complexity and dynamics of these interactions by following an omics-based approach exclusively, which are expensive and time-consuming. Additionally, this approach needs destructive sampling methods. Live-cell attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectrometry is well suited to provide noninvasive approach to provide rapid screening of cellular responses to potentially toxic NSPs or any stimuli. Herein we review the technical basis of the approach, the instrument configuration and interface with the biological media, and various effects that impact the data, data analysis, and toxicity. Our preliminary results on live-cell monitoring show promise for rapid screening the NSPs.

  17. Automated cell colony counting and analysis using the circular Hough image transform algorithm (CHiTA)

    Energy Technology Data Exchange (ETDEWEB)

    Bewes, J M; Suchowerska, N; McKenzie, D R [School of Physics, University of Sydney, Sydney, NSW (Australia)], E-mail: jbewes@physics.usyd.edu.au

    2008-11-07

    We present an automated cell colony counting method that is flexible, robust and capable of providing more in-depth clonogenic analysis than existing manual and automated approaches. The full form of the Hough transform without approximation has been implemented, for the first time. Improvements in computing speed have facilitated this approach. Colony identification was achieved by pre-processing the raw images of the colonies in situ in the flask, including images of the flask edges, by erosion, dilation and Gaussian smoothing processes. Colony edges were then identified by intensity gradient field discrimination. Our technique eliminates the need for specialized hardware for image capture and enables the use of a standard desktop scanner for distortion-free image acquisition. Additional parameters evaluated included regional colony counts, average colony area, nearest neighbour distances and radial distribution. This spatial and qualitative information extends the utility of the clonogenic assay, allowing analysis of spatially-variant cytotoxic effects. To test the automated system, two flask types and three cell lines with different morphology, cell size and plating density were examined. A novel Monte Carlo method of simulating cell colony images, as well as manual counting, were used to quantify algorithm accuracy. The method was able to identify colonies with unusual morphology, to successfully resolve merged colonies and to correctly count colonies adjacent to flask edges.

  18. Automated cell colony counting and analysis using the circular Hough image transform algorithm (CHiTA)

    Science.gov (United States)

    Bewes, J. M.; Suchowerska, N.; McKenzie, D. R.

    2008-11-01

    We present an automated cell colony counting method that is flexible, robust and capable of providing more in-depth clonogenic analysis than existing manual and automated approaches. The full form of the Hough transform without approximation has been implemented, for the first time. Improvements in computing speed have facilitated this approach. Colony identification was achieved by pre-processing the raw images of the colonies in situ in the flask, including images of the flask edges, by erosion, dilation and Gaussian smoothing processes. Colony edges were then identified by intensity gradient field discrimination. Our technique eliminates the need for specialized hardware for image capture and enables the use of a standard desktop scanner for distortion-free image acquisition. Additional parameters evaluated included regional colony counts, average colony area, nearest neighbour distances and radial distribution. This spatial and qualitative information extends the utility of the clonogenic assay, allowing analysis of spatially-variant cytotoxic effects. To test the automated system, two flask types and three cell lines with different morphology, cell size and plating density were examined. A novel Monte Carlo method of simulating cell colony images, as well as manual counting, were used to quantify algorithm accuracy. The method was able to identify colonies with unusual morphology, to successfully resolve merged colonies and to correctly count colonies adjacent to flask edges.

  19. Transforming Growth Factor-β2 Gene Cloning and Protein Expression in Human Trabecular Meshwork Cells

    Institute of Scientific and Technical Information of China (English)

    曹阳; 魏厚仁; 笪邦红; 李忠玉

    2003-01-01

    Whether cultured human trabecular meshwork cells express transforming growth factor-β2 (TGF-β2) messenger RNA (mRNA) and protein was investigated. Total RNA of 106 cultured human trabecular meshwork cells was extracted with TRIZOL reagent, reverse transcriptase-polymerase chain reaction (RT-PCR) were used for detection of TGF-β2 messenger RNA, and the PCRproduct was verified by sequencing. Immunohistochemical staining was used to detect TGF-β2 protein. The results showed that a single RT-PCR amplified product was obtained, and the sequence was homologous to the known sequence. TGF-β2 immunostaining was positive. It was concluded that trabecular meshwork cells could produce TGF-β2 and contribute to the presence of TGF-β2 in trabecular meshwork microenvironment as well as aqueous humor. Trabecular meshwork cells were affected by TGF-β2 not only through paracrine, but also autocrine action. Whether abnormal changes in TGF-β2 production contribute to the pathogenesis of primary open-angle glaucoma is worth further in vestigation.

  20. Cell differentiation, secondary cell-wall formation and transformation of callus tissue of Pinus radiata D. Don.

    Science.gov (United States)

    Möller, Ralf; McDonald, Armando G; Walter, Christian; Harris, Philip J

    2003-09-01

    Tracheid and sclereid differentiation was induced in callus cultures of Pinus radiata D. Don by culturing on a basal medium containing activated charcoal but no phytohormones; sclereids differentiated in callus derived from xylem strips, but not in callus derived from hypocotyl segments. The tracheids differentiated in hypocotyl-derived callus had helical, scalariform, reticulated or pitted secondary cell-wall patterns, but those differentiated in xylem-derived callus had a reticulate or pitted pattern. The thickened tracheid and sclereid walls contained lignin as indicated by the red colour reaction given with phloroglucinol-HCl. The presence of lignin in the cell walls of differentiated callus was confirmed using pyrolysis gas chromatography-mass spectrometry by the detection of phenylpropanoid components derived from lignin. Lignin was also detected using solid-state (13)C cross-polarisation/magic-angle spinning nuclear magnetic resonance spectroscopy and quantified as thioglycolic acid lignin. Monosaccharide analyses of the cell walls isolated from differentiated and undifferentiated calli showed that the cell walls of the differentiated calli contained higher proportions of glucose and mannose, consistent with the presence of greater proportions of gluco- and/or galactogluco-mannans in the secondary cell walls of the differentiated cells. A protocol for the stable transformation of undifferentiated, xylem-derived cultures was successfully developed. Transgenic cell lines were established following Biolistic particle bombardment with a plasmid containing the coding region of the nptII gene and the coding region of the cad gene from P. radiata. Expression of the nptII gene in transgenic lines was confirmed by an NPTII-enzyme-linked immunosorbent assay. The overexpression of cad in the transgenic lines resulted in a down-regulation of cinnamyl alcohol dehydrogenase (EC 1.1.1.195) expression. PMID:12811558

  1. Transient HEXA expression in a transformed human fetal Tay-Sachs disease neuroglial cell line

    Energy Technology Data Exchange (ETDEWEB)

    Fernandes, M.J.; Hechtman, P.; Kaplan, F. [McGill Univ., Quebec (Canada)] [and others

    1994-09-01

    Tay-Sachs disease (TSD) is a severe neurodegenerative disorder characterized by the accumulation of GM{sub 2} ganglioside in the neurons of the central cortex. The recessively inherited disorder results from deficiency of hexosaminidase A (Hex A), a heterodimer of an {alpha} and {beta} subunit encoded by the HEXA and HEXB genes. Expression of HEXA mutations in COS cells has several disadvantages including high endogenous hexosaminidase activity. We report a new transient expression system with very low endogenous Hex A activity. An SV40-transformed fetal TSD neuroglial cell line was assessed for transient expression of the HEXA gene. pCMV{alpha}, a vector incorporating the cytomegalovirus promoter with the human {alpha}-subunit cDNA insert, proved to be the most efficient expression vector. Transfection of 4x10{sup 6} cells with 5-20 {mu}g of plasmid resulted in 100 to 500-fold Hex A activity (4MUGS hydrolysis) relative to mock-transfected cells. Use of pCMV{beta}-Gal as a control for transfection efficiency indicated that 10-20% of cells were transfected. Hex A specific activity increased for at least 72 h post-transfection. This new transient expression system should greatly improve the characterization of mutations in which low levels of HEXA expression result in milder clinical phenotypes and permit studies on enzymatic properties of mutant forms of Hex A. Since the cells used are of CNS origin and synthesize gangliosides, it should also be possible to study, in culture, the metabolic phenotype associated with TSD.

  2. Caffeine toxicity is inversely related to DNA repair in simian virus 40-transformed xeroderma pigmentosum cells irradiated with ultraviolet light

    International Nuclear Information System (INIS)

    Human cells transformed by simian virus 40 (SV40) are more sensitive to killing by ultraviolet light when grown in caffeine after irradiation. The degree of sensitization at 2 mM caffeine (expressed as the ratio of the 37% survival dose for control cells divided by the 37% survival dose for cells grown in caffeine, i.e., the dose modification factor) was approximately 1.9 in transformed normal cells and 3.8-5.8 in excision-defective xeroderma pigmentosum (XP) groups A, C, and D cells. A large dose modification factor of 12 was observed in a transformed XP variant cell line. Chinese hamster ovary cells were not significantly different from transformed normal human cells, with a maximum dose modification factor of 1.5. Two radioresistant XP revertants that do not excise cyclobutane dimers gave different responses; one resembled its group A parent in being sensitized by caffeine, and one did not. These results can be interpreted on the basis of a single hypothesis that cells are killed as a result of attempts to replicate damaged DNA. Increased replication rates caused by transformation, increased numbers of replication forks in DNA caused by caffeine, and increased numbers of damaged sites ahead of replication forks in excision-defective cells are all processes that will consequently increase killing according to this hypothesis. A corollary is that the XP variant may be highly sensitized to caffeine because of excision defects at the DNA replication forks, an idea that may be important in designing cloning strategies for the XP variant gene

  3. Expression of P2 receptors in human B cells and Epstein-Barr virus-transformed lymphoblastoid cell lines

    Directory of Open Access Journals (Sweden)

    Kim Jun Woo

    2006-09-01

    Full Text Available Abstract Background Epstein-Barr virus (EBV infection immortalizes primary B cells in vitro and generates lymphoblastoid cell lines (LCLs, which are used for several purposes in immunological and genetic studies. Purinergic receptors, consisting of P2X and P2Y, are activated by extracellular nucleotides in most tissues and exert various physiological effects. In B cells, especially EBV-induced LCLs, their expression and function have not been well studied. We investigated the expression of P2 receptors on primary human B cells and LCLs using the quantitative reverse transcriptase-polymerase chain reaction (RT-PCR method for revealing the gene expression profile of the P2 receptor subtypes and their changes during transformation. Results The mRNA transcripts of most P2 receptors were detected in primary B cells; the expression of P2X3 and P2X7 receptors was the lowest of all the P2 receptors. By contrast, LCLs expressed several dominant P2 receptors – P2X4, P2X5, and P2Y11 – in amounts similar to those seen in B cells infected with EBV for 2 weeks. The amount of most P2 subtypes in LCLs or EBV-infected B cells was lower than in normal B cells. However, the amount of P2X7 receptor expressed in LCLs was higher. Protein expression was studied using Western blotting to confirm the mRNA findings for P2X1, P2X4, P2X7, P2Y1, and P2Y11 receptors. ATP increased the intracellular free Ca2+ concentration ([Ca2+]i by enhancing the Ca2+ influx in both B cells and LCLs in a dose-dependent manner. Conclusion These findings describe P2 receptor expression profiles and the effects of purinergic stimuli on B cells and suggest some plasticity in the expression of the P2 receptor phenotype. This may help explain the nature and effect of P2 receptors on B cells and their role in altering the characteristics of LCLs.

  4. Inactivation of the transforming growth factor beta type II receptor in human small cell lung cancer cell lines

    DEFF Research Database (Denmark)

    Hougaard, S; Nørgaard, P; Abrahamsen, N;

    1999-01-01

    Transforming growth factor beta (TGF-beta) exerts a growth inhibitory effect on many cell types through binding to two types of receptors, the type I and II receptors. Resistance to TGF-beta due to lack of type II receptor (RII) has been described in some cancer types including small cell lung...... cancer (SCLC). The purpose of this study was to examine the cause of absent RII expression in SCLC cell lines. Northern blot analysis showed that RII RNA expression was very weak in 16 of 21 cell lines. To investigate if the absence of RII transcript was due to mutations, we screened the poly-A tract...... of the mutation, which has not previously been observed in RII, has been linked to exposure to benzo[a]-pyrene, a component of cigarette smoke. Since RII has been mapped to chromosome 3p22 and nearby loci are often hypermethylated in SCLC, it was examined whether the lack of RII expression was due...

  5. Increased UV resistance in xeroderma pigmentosum group A cells after transformation with a human genomic DNA clone

    International Nuclear Information System (INIS)

    Xeroderma pigmentosum (XP) is an autosomal recessive disease in which the major clinical manifestation is a 2,000-fold enhanced probability of developing sunlight-induced skin tumors, and the molecular basis for the disease is a defective DNA excision repair system. To clone the gene defective XP complementation group A (XP-A), cDNA clones were isolated by a competition hybridization strategy in which the corresponding mRNAs were more abundant in cells of the obligately heterozygous parents relative to cells to the homozygous proband affected with the disease. In this report, a human genomic DNA clone that contains this cDNA was transformed into two independent homozygous XP-A cell lines, and these transformants displayed partial restoration of resistance to the killing effects of UV irradiation. The abundance of mRNA corresponding to this cDNA appears to correlate well with the observed UV cell survival. The results of unscheduled DNA synthesis after UV exposure indicate that the transformed cells are repair proficient relative to that of the control XP-A cells. However, using this same genomic DNA, transformation of an XP-F cell line did not confer any enhancement of UV survival or promote unscheduled DNA synthesis after UV exposure

  6. Fourier transform infrared spectroscopy for the distinction of MCF-7 cells treated with different concentrations of 5-fluorouracil

    OpenAIRE

    WU, BI-BO; Gong, Yi-Ping; Wu, Xin-Hong; Chen, Yuan-Yuan; Chen, Fang-Fang; Jin, Li-Ting; Cheng, Bo-Ran; Hu, Fen; Xiong, Bin

    2015-01-01

    Background In order to provide personalized treatment to patients with breast cancer, an accurate, reliable and cost-efficient analytical technique is needed for drug screening and evaluation of tumor response to chemotherapy. Methods Attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) was used as a tool to assess cancer cell response to chemotherapy. MCF-7 cells (human breast adenocarcinoma cell line) were treated with different concentrations of 5-fluorouracil (5...

  7. Transforming growth factor-β2 induces morphological alteration of human corneal endothelial cells in vitro

    Institute of Scientific and Technical Information of China (English)

    Jing; Wang; Ting-Jun; Fan; Xiu-Xia; Yang; Shi-Min; Chang

    2014-01-01

    AIM:To investigate the morphological altering effect of transforming growth factor-β2(TGF-β2) on untransfected human corneal endothelial cells(HCECs)in vitro.METHODS:After untransfected HCECs were treated with TGF-β2 at different concentrations, the morphology,cytoskeleton distribution, and type IV collagen expression of the cells were examined with inverted contrast light microscopy, fluorescence microscopy,immunofluorescence or Western Blot.RESULTS:TGF-β2 at the concentration of 3-15 μg/L had obviously alterative effects on HCECs morphology in dose and time-dependent manner, and 9 μg/L was the peak concentration. TGF-β2(9 μg/L) altered HCE cell morphology after treatment for 36 h, increased the mean optical density(P <0.01) and the length of F-actin,reduced the mean optical density(P <0.01) of the collagen type IV in extracellular matrix(ECM) and induced the rearrangement of F-actin, microtubule in cytoplasm and collagen type IV in ECM after treatment for 72 h.·CONCLUTION: TGF-β2 has obviously alterative effect on the morphology of HCECs from polygonal phenotype to enlarged spindle-shaped phenotype, in dose and time-dependence manner by inducing more, elongation and alignment of F-actin, rearrangement of microtubule and larger spread area of collagen type IV.

  8. Directly transforming PCR-amplified DNA fragments into plant cells is a versatile system that facilitates the transient expression assay.

    Directory of Open Access Journals (Sweden)

    Yuming Lu

    Full Text Available A circular plasmid containing a gene coding sequence has been broadly used for studying gene regulation in cells. However, to accommodate a quick screen plasmid construction and preparation can be time consuming. Here we report a PCR amplified dsDNA fragments (PCR-fragments based transient expression system (PCR-TES for suiting in the study of gene regulation in plant cells. Instead of transforming plasmids into plant cells, transient expression of PCR-fragments can be applicable. The transformation efficiency and expression property of PCR-fragments are comparable to transformation using plasmids. We analyzed the transformation efficiency in PCR-TES at transcription and protein levels. Our results indicate that the PCR-TES is as versatile as the conventional transformation system using plasmid DNA. Through reconstituting PYR1-mediated ABA signaling pathway in Arabidopsis mesophyll protoplasts, we were not only validating the practicality of PCR-TES but also screening potential candidates of CDPK family members which might be involved in the ABA signaling. Moreover, we determined that phosphorylation of ABF2 by CPK4 could be mediated by ABA-induced PYR1 and ABI1, demonstrating a crucial role of CDPKs in the ABA signaling. In summary, PCR-TES can be applicable to facilitate analyzing gene regulation and for the screen of putative regulatory molecules at the high throughput level in plant cells.

  9. The Effects of Physicochemical Factors and Cell Density on Nitrite Transformation in a Lipid-Rich Chlorella.

    Science.gov (United States)

    Liang, Fang; Du, Kui; Wen, Xiaobin; Luo, Liming; Geng, Yahong; Li, Yeguang

    2015-12-28

    To understand the effects of physicochemical factors on nitrite transformation by microalgae, a lipid-rich Chlorella with high nitrite tolerance was cultured with 8 mmol/l sodium nitrite as sole nitrogen source under different conditions. The results showed that nitrite transformation was mainly dependent on the metabolic activities of algal cells rather than oxidation of nitrite by dissolved oxygen. Light intensity, temperature, pH, NaHCO3 concentrations, and initial cell densities had significant effects on the rate of nitrite transformation. Single-factor experiments revealed that the optimum conditions for nitrite transformation were light intensity: 300 μmol/m(2); temperature: 30°C; pH: 7-8; NaHCO3 concentration: 2.0 g/l; and initial cell density: 0.15 g/l; and the highest nitrite transformation rate of 1.36 mmol/l/d was achieved. There was a positive correlation between nitrite transformation rate and the growth of Chlorella. The relationship between nitrite transformation rate (mg/l/d) and biomass productivity (g/l/d) could be described by the regression equation y = 61.3x (R(2) = 0.9665), meaning that 61.3 mg N element was assimilated by 1.0 g dry biomass on average, which indicated that the nitrite transformation is a process of consuming nitrite as nitrogen source by Chlorella. The results demonstrated that the Chlorella suspension was able to assimilate nitrite efficiently, which implied the feasibility of using flue gas for mass production of Chlorella without preliminary removal of NOX.

  10. H-ras-transformed NRK-52E renal epithelial cells have altered growth, morphology, and cytoskeletal structure that correlates with renal cell carcinoma in vivo.

    Science.gov (United States)

    Best, C J; Tanzer, L R; Phelps, P C; Merriman, R L; Boder, G G; Trump, B F; Elliget, K A

    1999-04-01

    We studied the effect of the ras oncogene on the growth kinetics, morphology, cytoskeletal structure, and tumorigenicity of the widely used NRK-52E rat kidney epithelial cell line and two H-ras oncogene-transformed cell lines, H/1.2-NRK-52E (H/1.2) and H/6.1-NRK-52E (H/6.1). Population doubling times of NRK-52E, H/1.2, and H/6.1 cells were 28, 26, and 24 h, respectively, with the transformed cells reaching higher saturation densities than the parent cells. NRK-52E cells had typical epithelial morphology with growth in colonies. H/1.2 and H/6.1 cell colonies were more closely packed, highly condensed, and had increased plasma membrane ruffling compared to parent cell colonies. NRK-52E cells showed microfilament, microtubule, and intermediate filament networks typical of epithelial cells, while H/1.2 and H/6.1 cells showed altered cytoskeleton architecture, with decreased stress fibers and increased microtubule and intermediate filament staining at the microtubule organizing center. H/1.2 and H/6.1 cells proliferated in an in vitro soft agar transformation assay, indicating anchorage-independence, and rapidly formed tumors in vivo with characteristics of renal cell carcinoma, including mixed populations of sarcomatoid, granular, and clear cells. H/6.1 cells consistently showed more extensive alterations of growth kinetics, morphology, and cytoskeleton than H/1.2 cells, and formed tumors of a more aggressive phenotype. These data suggest that analysis of renal cell characteristics in vitro may have potential in predicting tumor behavior in vivo, and significantly contribute to the utility of these cell lines as in vitro models for examining renal epithelial cell biology and the role of the ras proto-oncogene in signal transduction involving the cytoskeleton.

  11. In vitro comet and micronucleus assays do not predict morphological transforming effects of silica particles in Syrian Hamster Embryo cells.

    Science.gov (United States)

    Darne, Christian; Coulais, Catherine; Terzetti, Francine; Fontana, Caroline; Binet, Stéphane; Gaté, Laurent; Guichard, Yves

    2016-01-15

    Crystalline silica particles and asbestos have both been classified as carcinogenic by the International Agency for Research on Cancer (IARC). However, because of the limited data available, amorphous silica was not classifiable. In vitro, the carcinogenic potential of natural crystalline and amorphous silica particles has been revealed by the Syrian Hamster Embryo (SHE) cell transformation assay. On the other hand, the genotoxic potential of those substances has not been investigated in SHE cells. And yet, genotoxicity assays are commonly used for hazard evaluation and they are often used as in vitro assays of reference to predict a possible carcinogenic potential. The main objective of this study was to compare the genotoxic potential and the carcinogenic potential of different crystalline and amorphous silica particles in SHE cells. Three silica samples of different crystallinity were used: natural amorphous silica, partially crystallized silica and quartz silica particles. Their genotoxicity were tested through the in vitro micronucleus assay and the comet assay in SHE, and their carcinogenic potential through the SHE transformation assay. In addition, silica samples were also tested with the same genotoxicity assays in V79 hamster-lung cells, a common in vitro model for particle exposure. Results obtained in the micronucleus and the comet assays show that none of the silica was capable of inducing genotoxic effects in SHE cells and only the amorphous silica induced genotoxic effects in V79 cells. However in the SHE cell transformation assays, the partially crystallized and quartz silica were able to induce morphological cell transformation. Together, these data suggest that, in vitro, the short-term genotoxic assays alone are not sufficient to predict the hazard and the carcinogenic potential of this type of particles; SHE transformation assay appears a more reliable tool for this purpose and should be included in the "in vitro battery assays" for hazard

  12. 78-kilodalton glucose-regulated protein is induced in Rous sarcoma virus-transformed cells independently of glucose deprivation.

    OpenAIRE

    Stoeckle, M Y; Sugano, S; Hampe, A; Vashistha, A; Pellman, D.; Hanafusa, H

    1988-01-01

    To identify mRNAs with altered expression in Rous sarcoma virus (RSV)-transformed cells, we screened a chicken embryo fibroblast (CEF) cDNA library by differential hybridization. One clone, designated R1H, showed markedly elevated mRNA expression in RSV-transformed cells. Nucleotide sequence analysis indicated that R1H mRNA encodes 78-kilodalton glucose-regulated protein (GRP78). Chicken GRP78 was found to be very highly conserved in comparison with rat GRP78 (96% identity between chicken and...

  13. Antibody to Heat Shock Protein 70 (HSP70) Inhibits Human T-Cell Lymphoptropic Virus Type I (HTLV-I) Production by Transformed Rabbit T-Cell Lines

    OpenAIRE

    Hanan Fallouh; Wahib Mahana

    2012-01-01

    Adult T cell leukemia is a fatal malignant transformation caused by the human T-cell lymphoptropic virus type I (HTLV-I). HTLV-I is only associated with the development of this disease in a small percentage of infected individuals. Using two rabbit transformed T-cell lines; RH/K30 (asymptomatic) and RH/K34 (leukemogenic), we have investigated the expression of heat shock proteins (HSP) 90 and 70 and the role of anti-HSPs antibodies on virus production. HSPs surface expression was higher on RH...

  14. Ultraconserved region-containing Transformer 2β4 controls senescence of colon cancer cells.

    Science.gov (United States)

    Kajita, K; Kuwano, Y; Satake, Y; Kano, S; Kurokawa, K; Akaike, Y; Masuda, K; Nishida, K; Rokutan, K

    2016-01-01

    Ultraconserved regions (UCRs) are >200 bp genomic segments with perfect human-to-rodent sequence identity. Transcribed UCRs constitute a new category of noncoding RNAs whose functions remain poorly understood. The human transformer 2β (TRA2B) gene contains a 419-bp UCR spanning the 276-bp exon 2 and its neighboring introns. TRA2B exon 2 has premature stop codons, whereas an exon 2-containing splice variant (TRA2β4) was expressed preferentially in the nuclei of human colon cancer cells. TRA2β4 knockdown p53-independently stimulated CDKN1A transcription and increased p21, resulting in the appearance of senescent cells. Biotin pull-down and RNA immunoprecipitation assays revealed that TRA2β4 interacted with Sp1 through a Sp1-binding sequence (485-GGGG-488) in a stem-loop structure of exon 2. Mutation of this sequence (485-AAGG-488) disrupted the stem-loop structure, blocked the interaction with Sp1 and increased CDKN1A transcription. Overexpression of TRA2β4 significantly decreased CDKN1A mRNA levels and accelerated cell growth, but the introduction of the mutation in the Sp1-binding sequence completely canceled these effects. Taken together, TRA2β4 may sequester Sp1 from occupying promoters of target genes including CDKN1A, promoting cell growth by interrupting the senescence-related gene expression program. This novel function of TRA2β4 may uncover an oncogenic function of transcribed UCRs. PMID:27043659

  15. Ca2+ transport in plant cells and mechanisms of transformation of phytochrome-induced photosignals

    Science.gov (United States)

    Volotovski, Igor D.

    1995-01-01

    The recent data on the influence of phytochrome on the efficiency of Ca2+ translocation across the membranes of oat protoplasts are given. Ca2+ uptake in the protoplasts was shown to be influenced by the red light (R) illumination. This effect was reverted by the following far-red light (FR) illumination. To elucidate the sensitivity to phytochrome-controlling action the screening between the mechanisms of Ca2+ transport across the plasma membranes of oat protoplasts, Na+/Ca2+ and Ca2+/H+ exchangers, Ca2+-pump and Ca2+-channel was done. It was established that phytochrome modulated the activity of Na+/Ca2+-exchanger and Ca2+-pump. The light-mediated oscillations of cytoplasmic Ca2+ concentration in the oat protoplasts were demonstrated using fluorescence probe quin2 loaded into the cells and laser monitoring of fluorescence signal. The evidences were obtained that the oscillations were not the result of the elevation of cytoplasmic Ca2+ concentration and had no connection with Ca2+ pool of mitochondria. The possibility of the relation between the Ca2+ oscillations and phosphoinositide metabolism in plant cell membranes is analyzed. The mechanisms of transformation of primary phytochrome signal into biological effects were discussed.

  16. Titanium Dioxide (TiO2) Nanoparticles Preferentially Induce Cell Death in Transformed Cells in a Bak/Bax-Independent Fashion

    OpenAIRE

    Yanglong Zhu; Eaton, John W.; Chi Li

    2012-01-01

    While the cytotoxic effects of titanium dioxide (TiO(2)) nanoparticles have been under intense investigation, the molecular mechanisms of this cytotoxicity remain unknown. Here we investigated the influence of oncogenic transformation and a major apoptotic signaling pathway on cellular responses to TiO(2) nanoparticles. Isogenic wild-type (WT) and apoptosis-resistant (Bak(-/-)Bax(-/-)) cell lines with and without tumorigenic transformation were examined. TiO(2) nanoparticles preferentially re...

  17. Suberoylanilide hydroxamic acid (SAHA) inhibits EGF-induced cell transformation via reduction of cyclin D1 mRNA stability

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Jingjie [State Key Laboratory of Natural and Biomimetic Drugs, Department of Pharmacology, School of Basic Medical Sciences, Peking University, 38 Xueyuan Rd, Haidian District, Beijing 100191 (China); Nelson Institute of Environmental Medicine, New York University School of Medicine, 57 Old Forge Rd, Tuxedo, NY 10987 (United States); Ouyang, Weiming; Li, Jingxia; Zhang, Dongyun; Yu, Yonghui; Wang, York [Nelson Institute of Environmental Medicine, New York University School of Medicine, 57 Old Forge Rd, Tuxedo, NY 10987 (United States); Li, Xuejun, E-mail: xjli@bjmu.edu.cn [State Key Laboratory of Natural and Biomimetic Drugs, Department of Pharmacology, School of Basic Medical Sciences, Peking University, 38 Xueyuan Rd, Haidian District, Beijing 100191 (China); Huang, Chuanshu, E-mail: chuanshu.huang@nyumc.org [Nelson Institute of Environmental Medicine, New York University School of Medicine, 57 Old Forge Rd, Tuxedo, NY 10987 (United States)

    2012-09-01

    Suberoylanilide hydroxamic acid (SAHA) inhibiting cancer cell growth has been associated with its downregulation of cyclin D1 protein expression at transcription level or translation level. Here, we have demonstrated that SAHA inhibited EGF-induced Cl41 cell transformation via the decrease of cyclin D1 mRNA stability and induction of G0/G1 growth arrest. We found that SAHA treatment resulted in the dramatic inhibition of EGF-induced cell transformation, cyclin D1 protein expression and induction of G0/G1 growth arrest. Further studies showed that SAHA downregulation of cyclin D1 was only observed with endogenous cyclin D1, but not with reconstitutionally expressed cyclin D1 in the same cells, excluding the possibility of SAHA regulating cyclin D1 at level of protein degradation. Moreover, SAHA inhibited EGF-induced cyclin d1 mRNA level, whereas it did not show any inhibitory effect on cyclin D1 promoter-driven luciferase reporter activity under the same experimental conditions, suggesting that SAHA may decrease cyclin D1 mRNA stability. This notion was supported by the results that treatment of cells with SAHA decreased the half-life of cyclin D1 mRNA from 6.95 h to 2.57 h. Consistent with downregulation of cyclin D1 mRNA stability, SAHA treatment also attenuated HuR expression, which has been well-characterized as a positive regulator of cyclin D1 mRNA stability. Thus, our study identifies a novel mechanism responsible for SAHA inhibiting cell transformation via decreasing cyclin D1 mRNA stability and induction of G0/G1 growth arrest in Cl41 cells. -- Highlights: ► SAHA inhibits cell transformation in Cl41 cells. ► SAHA suppresses Cyclin D1 protein expression. ► SAHA decreases cyclin D1 mRNA stability.

  18. Impairments of cells and genomic DNA by environmentally transformed engineered nanomaterials

    Science.gov (United States)

    Jones, Philip; Sugino, Sakiko; Yamamura, Shohei; Lacy, Fred; Biju, Vasudevanpillai

    2013-09-01

    Enormous increase in the production of nanomaterials and their growing applications in the device technology, biotechnology and biomedical areas suggest the need for developing models for predicting the environmental health and safety (EHS) risks posed by such nanomaterials. We hypothesize that CdSe quantum dots (QDs) and ZnO nanoparticles (NPs) encompassed in liposomes or not and transformed by simulated solar UV light can be model systems for studying the environmental toxicity of engineered nanomaterials. In this study, human lung epithelial adenocarcinoma cells (H1650) are exposed to photoirradiated CdSe QDs or ZnO nanopowder included or not in liposomes. The release of cadmium and zinc ions from the nanomaterials exposed to solar simulated UV radiation is detected and quantified by measuring the steady-state and time resolved fluorescence of the metal ion sensor tetracarboxyphenylporphyrin (TCPP) or the commercial Measure iT Pd/Cd sensor. Viability of cells treated with nanomaterials exposed to solar simulated UV radiation for different durations is measured by MTT assay. Enhanced etching of the nanoparticles exposed to solar simulated UV radiation results in the release of toxic levels of heavy metal ions, which considerably lower the viability of H1650 cells is due to the deactivation of DNA repair enzymes as evidenced by the pinching off of nuclear DNA in comet assays and DNA samples in electrophoresis. Results from this study highlight the need to obtain not only quantitative information about the environmental risks posed by engineered nanomaterials but also environment friendly nanomaterials for practical applications.Enormous increase in the production of nanomaterials and their growing applications in the device technology, biotechnology and biomedical areas suggest the need for developing models for predicting the environmental health and safety (EHS) risks posed by such nanomaterials. We hypothesize that CdSe quantum dots (QDs) and ZnO nanoparticles

  19. Human Dynactin-Associated Protein Transforms NIH3T3 Cells to Generate Highly Vascularized Tumors with Weak Cell-Cell Interaction.

    Directory of Open Access Journals (Sweden)

    Tatsuki Kunoh

    Full Text Available Human dynactin-associated protein (dynAP is a transmembrane protein that promotes AktSer473 phosphorylation. Here, we report the oncogenic properties of dynAP. In contrast to control NIH3T3 cells expressing LacZ (NIH3T3LacZ, NIH3T3dynAP cells vigorously formed foci in two-dimensional culture, colonies on soft agar, and spheroids in anchorage-deficient three-dimensional culture. NIH3T3dynAP cells injected into nude mice produced tumors with abundant blood vessels and weak cell-cell contacts. Expression of dynAP elevated the level of rictor (an essential subunit of mTORC2 and promoted phosphorylation of FOXO3aSer253. FOXO3a is a transcriptional factor that stimulates expression of pro-apoptotic genes and phosphorylation of FOXO3a abrogates its function, resulting in promoted cell survival. Knockdown of rictor in NIH3T3dynAP cells reduced AktSer473 phosphorylation and formation of foci, colony in soft agar and spheroid, indicating that dynAP-induced activation of the mTORC2/AktSer473 pathway for cell survival contributes to cell transformation. E-cadherin and its mRNA were markedly reduced upon expression of dynAP, giving rise to cells with higher motility, which may be responsible for the weak cell-cell adhesion in tumors. Thus, dynAP could be a new oncoprotein and a target for cancer therapy.

  20. Deregulation of histone lysine methyltransferases contributes to oncogenic transformation of human bronchoepithelial cells

    Directory of Open Access Journals (Sweden)

    Yoda Satoshi

    2008-11-01

    Full Text Available Abstract Background Alterations in the processing of the genetic information in carcinogenesis result from stable genetic mutations or epigenetic modifications. It is becoming clear that nucleosomal histones are central to proper gene expression and that aberrant DNA methylation of genes and histone methylation plays important roles in tumor progression. To date, several histone lysine methyltransferases (HKMTs have been identified and histone lysine methylation is now considered to be a critical regulator of transcription. However, still relatively little is known about the role of HKMTs in tumorigenesis. Results We observed differential HKMT expression in a lung cancer model in which normal human bronchial epithelial (NHBE cells expressing telomerase, SV40 large T antigen, and Ras were immortal, formed colonies in soft agar, and expressed specific HKMTs for H3 lysine 9 and 27 residues but not for H3 lysine 4 residue. Modifications in the H3 tails affect the binding of proteins to the histone tails and regulate protein function and the position of lysine methylation marks a gene to be either activated or repressed. In the present study, suppression by siRNA of HKMTs (EZH2, G9A, SETDB1 and SUV39H1 that are over-expressed in immortalized and transformed cells lead to reduced cell proliferation and much less anchorage-independent colony growth. We also found that the suppression of H3-K9, G9A and SUV39H1 induced apoptosis and the suppression of H3-K27, EZH2 caused G1 arrest. Conclusion Our results indicate the potential of these HKMTs in addition to the other targets for epigenetics such as DNMTs and HDACs to be interesting therapeutic targets.

  1. A Novel High Performance Fourier Transform Ion Cyclotron Resonance Cell for Improved Biopolymer Characterization

    Energy Technology Data Exchange (ETDEWEB)

    Bruce, James E.(BATTELLE (PACIFIC NW LAB)); Anderson, Gordon A.(BATTELLE (PACIFIC NW LAB)); Lin, Chuan-Yuan (ASSOC WESTERN UNIVERSITY); Gorshkov, Michael V.(OFFICE OF FELLOWSHIP PROG); Rockwood, Alan L.(BATTELLE (PACIFIC NW LAB)); Smith, Richard D.(BATTELLE (PACIFIC NW LAB))

    2000-02-22

    A new trapped ion cell design for use with Fourier transform ion cyclotron resonance mass spectrometry is described. The design employs 15 cylindrical ring electrodes to generate trapping potential wells and 32 separately assignable rod electrodes for excitation and detection. The rod electrodes are positioned internal to the ring electrodes and provide excitation fields that are thereby linearized along the magnetic field over the entire trapped ion volume. The new design also affords flexibility in the shaping of the trapping field using the 15 ring electrodes. Many different trapping well shapes can be generated by applying different voltages to the individual ring electrodes, ranging from quadratic to linearly ramped along the magnetic field axis, to a shape that is nearly flat over the entire trap volume, but rises very steeply near the ends of the trap. This feature should be useful for trapping larger ion populations and extension of the useful range of ion manipulation and dissociation experiments since the number of stages of ion manipulation or dissociation is limited in practice by the initial trapped ion population size. Predicted trapping well shapes for two different ring electrode configurations are presented and these and several other possible configurations are discussed, as are the predicted excitation fields based on the use of rod electrodes internal to the trapping ring electrodes. Initial results are presented from an implementation of the design using a 3.5 T superconducting magnet. It was found that ions can be successfully trapped and detected with this cell design and that selected ion accumulation can be performed with the utilization of four rods for quadrupolar excitation. The initial results presented here illustrate the feasibility of this cell design and demonstrate differences in observed performance based upon different trapping well shapes.

  2. SPARC Expression Is Selectively Suppressed in Tumor Initiating Urospheres Isolated from As+3- and Cd+2-Transformed Human Urothelial Cells (UROtsa Stably Transfected with SPARC.

    Directory of Open Access Journals (Sweden)

    Andrea Slusser-Nore

    Full Text Available This laboratory previously analyzed the expression of SPARC in the parental UROtsa cells, their arsenite (As(+3 and cadmium (Cd(+2-transformed cell lines, and tumor transplants generated from the transformed cells. It was demonstrated that SPARC expression was down-regulated to background levels in Cd(+2-and As(+3-transformed UROtsa cells and tumor transplants compared to parental cells. In the present study, the transformed cell lines were stably transfected with a SPARC expression vector to determine the effect of SPARC expression on the ability of the cells to form tumors in immune-compromised mice.Real time PCR, western blotting, immunohistochemistry, and immunofluorescence were used to define the expression of SPARC in the As(+3-and Cd(+2-transformed cell lines, and urospheres isolated from these cell lines, following their stable transfection with an expression vector containing the SPARC open reading frame (ORF. Transplantation of the cultured cells into immune-compromised mice by subcutaneous injection was used to assess the effect of SPARC expression on tumors generated from the above cell lines and urospheres.It was shown that the As(+3-and Cd(+2-transformed UROtsa cells could undergo stable transfection with a SPARC expression vector and that the transfected cells expressed both SPARC mRNA and secreted protein. Tumors formed from these SPARC-transfected cells were shown to have no expression of SPARC. Urospheres isolated from cultures of the SPARC-transfected As(+3-and Cd(+2-transformed cell lines were shown to have only background expression of SPARC. Urospheres from both the non-transfected and SPARC-transfected cell lines were tumorigenic and thus fit the definition for a population of tumor initiating cells.Tumor initiating cells isolated from SPARC-transfected As(+3-and Cd(+2-transformed cell lines have an inherent mechanism to suppress the expression of SPARC mRNA.

  3. Transforming growth factor-β synthesized by stromal cells and cancer cells participates in bone resorption induced by oral squamous cell carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, Ryosuke [Department of Oral Pathology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo (Japan); Department of Maxillofacial Surgery, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo (Japan); Kayamori, Kou [Department of Oral Pathology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo (Japan); Oue, Erika [Department of Oral Pathology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo (Japan); Department of Maxillofacial Surgery, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo (Japan); Sakamoto, Kei [Department of Oral Pathology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo (Japan); Harada, Kiyoshi [Department of Maxillofacial Surgery, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo (Japan); Yamaguchi, Akira, E-mail: akira.mpa@tmd.ac.jp [Department of Oral Pathology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo (Japan)

    2015-03-20

    Transforming growth factor beta (TGF-β) plays a significant role in the regulation of the tumor microenvironment. To explore the role of TGF-β in oral cancer-induced bone destruction, we investigated the immunohistochemical localization of TGF-β and phosphorylated Smad2 (p-Smad2) in 12 surgical specimens of oral squamous cell carcinoma (OSCC). These studies revealed TGF-β and p-Smad2 expression in cancer cells in all tested cases. Several fibroblasts located between cancer nests and resorbing bone expressed TGF-β in 10 out of 12 cases and p-Smad2 in 11 out of 12 cases. Some osteoclasts also exhibited p ∼ Smad2 expression. The OSCC cell line, HSC3, and the bone marrow-derived fibroblastic cell line, ST2, synthesized substantial levels of TGF-β. Culture media derived from HSC3 cells could stimulate Tgf-β1 mRNA expression in ST2 cells. Recombinant TGF-β1 could stimulate osteoclast formation induced by receptor activator of nuclear factor kappa-B ligand (RANKL) in RAW264 cells. TGF-β1 could upregulate the expression of p-Smad2 in RAW264 cells, and this action was suppressed by the addition of a neutralizing antibody against TGF-β or by SB431542. Transplantation of HSC3 cells onto the calvarial region of athymic mice caused bone destruction, associated with the expression of TGF-β and p-Smad2 in both cancer cells and stromal cells. The bone destruction was substantially inhibited by the administration of SB431542. The present study demonstrated that TGF-β synthesized by both cancer cells and stromal cells participates in the OSCC-induced bone destruction. - Highlights: • Cancer cell, fibroblastic cells, and osteoclasts at bone resorbing area by oral cancer exhibited TGF-β and p-Smad2. • TGF-β1 stimulated osteoclastogenesis induced by RAKL in RAW264 cell. • Xenograft model of oral cancer-induced bone resorption was substantially inhibited by SB431542. • TGF-β synthesized by both cancer cells and stromal cells participates in the OSCC

  4. Transforming growth factor-β synthesized by stromal cells and cancer cells participates in bone resorption induced by oral squamous cell carcinoma

    International Nuclear Information System (INIS)

    Transforming growth factor beta (TGF-β) plays a significant role in the regulation of the tumor microenvironment. To explore the role of TGF-β in oral cancer-induced bone destruction, we investigated the immunohistochemical localization of TGF-β and phosphorylated Smad2 (p-Smad2) in 12 surgical specimens of oral squamous cell carcinoma (OSCC). These studies revealed TGF-β and p-Smad2 expression in cancer cells in all tested cases. Several fibroblasts located between cancer nests and resorbing bone expressed TGF-β in 10 out of 12 cases and p-Smad2 in 11 out of 12 cases. Some osteoclasts also exhibited p ∼ Smad2 expression. The OSCC cell line, HSC3, and the bone marrow-derived fibroblastic cell line, ST2, synthesized substantial levels of TGF-β. Culture media derived from HSC3 cells could stimulate Tgf-β1 mRNA expression in ST2 cells. Recombinant TGF-β1 could stimulate osteoclast formation induced by receptor activator of nuclear factor kappa-B ligand (RANKL) in RAW264 cells. TGF-β1 could upregulate the expression of p-Smad2 in RAW264 cells, and this action was suppressed by the addition of a neutralizing antibody against TGF-β or by SB431542. Transplantation of HSC3 cells onto the calvarial region of athymic mice caused bone destruction, associated with the expression of TGF-β and p-Smad2 in both cancer cells and stromal cells. The bone destruction was substantially inhibited by the administration of SB431542. The present study demonstrated that TGF-β synthesized by both cancer cells and stromal cells participates in the OSCC-induced bone destruction. - Highlights: • Cancer cell, fibroblastic cells, and osteoclasts at bone resorbing area by oral cancer exhibited TGF-β and p-Smad2. • TGF-β1 stimulated osteoclastogenesis induced by RAKL in RAW264 cell. • Xenograft model of oral cancer-induced bone resorption was substantially inhibited by SB431542. • TGF-β synthesized by both cancer cells and stromal cells participates in the OSCC

  5. Secondary cell wall development in cotton fibers as examined with attenuated total reflection Fourier transform infrared spectroscopy

    Science.gov (United States)

    Cotton fibers harvested at 18, 20, 24, 28, 32, 36 and 40 days after flowering were examined using attenuated total reflection Fourier transform-infrared (ATR FT-IR) spectroscopy. The selected harvesting points coincide with secondary cell wall (SCW) development in the fibers. Progressive but moderat...

  6. Inhibition of protease-resistant prion protein formation in a transformed deer cell line infected with chronic wasting disease

    NARCIS (Netherlands)

    Raymond, G.J.; Olsen, E.A.; Lee, K.S.; Raymond, L.D.; Bryant, P.K.; Baron, G.S.; Caughey, W.S.; Kocisko, D.A.; McHolland, L.E.; Favara, C.; Langeveld, J.P.M.; Zijderveld, van F.G.; Mayer, R.T.; Miller, M.W.; Williams, E.S.; Caughey, B.

    2006-01-01

    Chronic wasting disease (CWD) is an emerging transmissible spongiform encephalopathy (prion disease) of North American cervids, i.e., mule deer, white-tailed deer, and elk (wapiti). To facilitate in vitro studies of CWD, we have developed a transformed deer cell line that is persistently infected wi

  7. Docetaxel Influences Autocrine of Transforming Growth Factors and Induces Apoptosis in Human Ovarian Cancer Cell Line AO

    Institute of Scientific and Technical Information of China (English)

    Yan Zhang; Ya-li Hu; Yun-ying Cheng

    2006-01-01

    @@ Ovarian cancer is the second most common malignancy of female reproductive tract. Docetaxel shows good clinical efficacy against ovarian cancer.This present study was to investigate the role of docetaxel on apoptosis of ovarian cancer epithelial cell line AO as well as the secretion of transforming growth factor (TGF)-α and TGF-β1 during apoptosis.

  8. Luteolin inhibits Cr(VI)-induced malignant cell transformation of human lung epithelial cells by targeting ROS mediated multiple cell signaling pathways

    Energy Technology Data Exchange (ETDEWEB)

    Pratheeshkumar, Poyil; Son, Young-Ok; Divya, Sasidharan Padmaja; Roy, Ram Vinod; Hitron, John Andrew; Wang, Lei [Center for Research on Environmental Disease, University of Kentucky, 1095 VA Drive, Lexington, KY 40536 (United States); Graduate Center for Toxicology, University of Kentucky, 1095 VA Drive, Lexington, KY 40536 (United States); Kim, Donghern; Dai, Jin [Graduate Center for Toxicology, University of Kentucky, 1095 VA Drive, Lexington, KY 40536 (United States); Asha, Padmaja [National Centre for Aquatic Animal Health, Cochin University of Science and Technology, Cochin (India); Zhang, Zhuo [Graduate Center for Toxicology, University of Kentucky, 1095 VA Drive, Lexington, KY 40536 (United States); Wang, Yitao [State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macau (China); Shi, Xianglin, E-mail: xshi5@email.uky.edu [Center for Research on Environmental Disease, University of Kentucky, 1095 VA Drive, Lexington, KY 40536 (United States); Graduate Center for Toxicology, University of Kentucky, 1095 VA Drive, Lexington, KY 40536 (United States)

    2014-12-01

    Hexavalent chromium [Cr(VI)] is a well-known human carcinogen associated with the incidence of lung cancer. Inhibition of metal induced carcinogenesis by a dietary antioxidant is a novel approach. Luteolin, a natural dietary flavonoid found in fruits and vegetables, possesses potent antioxidant and anti-inflammatory activity. We found that short term exposure of human bronchial epithelial cells (BEAS-2B) to Cr(VI) (5 μM) showed a drastic increase in ROS generation, NADPH oxidase (NOX) activation, lipid peroxidation, and glutathione depletion, which were significantly inhibited by the treatment with luteolin in a dose dependent manner. Treatment with luteolin decreased AP-1, HIF-1α, COX-2, and iNOS promoter activity induced by Cr(VI) in BEAS-2B cells. In addition, luteolin protected BEAS-2B cells from malignant transformation induced by chronic Cr(VI) exposure. Moreover, luteolin also inhibited the production of pro-inflammatory cytokines (IL-1β, IL-6, IL-8, TNF-α) and VEGF in chronic Cr(VI) exposed BEAS-2B cells. Western blot analysis showed that luteolin inhibited multiple gene products linked to survival (Akt, Fak, Bcl-2, Bcl-xL), inflammation (MAPK, NF-κB, COX-2, STAT-3, iNOS, TNF-α) and angiogenesis (HIF-1α, VEGF, MMP-9) in chronic Cr(VI) exposed BEAS-2B cells. Nude mice injected with BEAS-2B cells chronically exposed to Cr(VI) in the presence of luteolin showed reduced tumor incidence compared to Cr(VI) alone treated group. Overexpression of catalase (CAT) or SOD2, eliminated Cr(VI)-induced malignant transformation. Overall, our results indicate that luteolin protects BEAS-2B cells from Cr(VI)-induced carcinogenesis by scavenging ROS and modulating multiple cell signaling mechanisms that are linked to ROS. Luteolin, therefore, serves as a potential chemopreventive agent against Cr(VI)-induced carcinogenesis. - Highlights: • Luteolin inhibited Cr(VI)-induced oxidative stress. • Luteolin inhibited chronic Cr(VI)-induced malignant transformation.

  9. HTLV-1 tax stabilizes MCL-1 via TRAF6-dependent K63-linked polyubiquitination to promote cell survival and transformation.

    Science.gov (United States)

    Choi, Young Bong; Harhaj, Edward William

    2014-10-01

    The human T-cell leukemia virus type 1 (HTLV-1) Tax protein hijacks the host ubiquitin machinery to activate IκB kinases (IKKs) and NF-κB and promote cell survival; however, the key ubiquitinated factors downstream of Tax involved in cell transformation are unknown. Using mass spectrometry, we undertook an unbiased proteome-wide quantitative survey of cellular proteins modified by ubiquitin in the presence of Tax or a Tax mutant impaired in IKK activation. Tax induced the ubiquitination of 22 cellular proteins, including the anti-apoptotic BCL-2 family member MCL-1, in an IKK-dependent manner. Tax was found to promote the nondegradative lysine 63 (K63)-linked polyubiquitination of MCL-1 that was dependent on the E3 ubiquitin ligase TRAF6 and the IKK complex. Tax interacted with and activated TRAF6, and triggered its mitochondrial localization, where it conjugated four carboxyl-terminal lysine residues of MCL-1 with K63-linked polyubiquitin chains, which stabilized and protected MCL-1 from genotoxic stress-induced degradation. TRAF6 and MCL-1 played essential roles in the survival of HTLV-1 transformed cells and the immortalization of primary T cells by HTLV-1. Therefore, K63-linked polyubiquitination represents a novel regulatory mechanism controlling MCL-1 stability that has been usurped by a viral oncogene to precipitate cell survival and transformation.

  10. A detailed analysis of cyclin A accumulation at the G(1)/S border in normal and transformed cells.

    Science.gov (United States)

    Erlandsson, F; Linnman, C; Ekholm, S; Bengtsson, E; Zetterberg, A

    2000-08-25

    The temporal relationship between cyclin A accumulation and the onset of DNA replication was analyzed in detail. Five untransformed and nine transformed asynchronously growing cell cultures were investigated using a triple immunofluorescence staining protocol combined with computerized evaluation of staining intensities in individual cells. The simultaneous staining of BrdU, cyclin A, and cyclin E made it possible to determine the cell cycle position of each cell investigated. Cells at the G(1)/S border were identified on the basis of cyclin E content and were further analyzed with respect to cyclin A and BrdU content. A method was developed to calculate objective thresholds defining the highest staining intensity found in the negative cells in the population. Using the thresholds we could distinguish cells with minute amounts of cyclin A and BrdU from truly negative cells. We show that the onset of cyclin A accumulation and the start of DNA replication occurs at the same time, or deviating by a few minutes at the most. We also show that cyclin A accumulates continuously during S. This study clearly demonstrates that nuclear cyclin A can be used as a reliable marker for the S and G(2) phases in both normal and transformed interphase cells. PMID:10942581

  11. JAK3 mutants transform hematopoietic cells through JAK1 activation, causing T-cell acute lymphoblastic leukemia in a mouse model

    OpenAIRE

    Degryse, Sandrine; de Bock, Charles E.; Cox, Luk; Demeyer, Sofie; Gielen, Olga; Mentens, Nicole; Jacobs, Kris; Geerdens, Ellen; Gianfelici, Valentina; Hulselmans, Gert; Fiers, Mark; Aerts, Stein; Meijerink, Jules P.; Tousseyn, Thomas; Cools, Jan

    2014-01-01

    JAK3 is a tyrosine kinase that associates with the common γ chain of cytokine receptors and is recurrently mutated in T-cell acute lymphoblastic leukemia (T-ALL). We tested the transforming properties of JAK3 pseudokinase and kinase domain mutants using in vitro and in vivo assays. Most, but not all, JAK3 mutants transformed cytokine-dependent Ba/F3 or MOHITO cell lines to cytokine-independent proliferation. JAK3 pseudokinase mutants were dependent on Jak1 kinase activity for cellular transfo...

  12. Transforming growth factor-beta (TGF-beta) and programmed cell death in the vertebrate retina.

    Science.gov (United States)

    Duenker, Nicole

    2005-01-01

    Programmed cell death (PCD) is a precisely regulated phenomenon essential for the homeostasis of multicellular organisms. Developmental systems, particularly the nervous system, have provided key observations supporting the physiological role of PCD. We have recently shown that transforming growth factor-beta (TGF-beta) plays an important role in mediating ontogenetic PCD in the nervous system. As part of the central nervous system the developing retina serves as an ideal model system for investigating apoptotic processes during neurogenesis in vivo as it is easily accessible experimentally and less complex due to its limited number of different neurons. This review summarizes data indicating a pivotal role of TGF-beta in mediating PCD in the vertebrate retina. The following topics are discussed: expression of TGF-beta isoforms and receptors in the vertebrate retina, the TGF-beta signaling pathway, functions and molecular mechanisms of PCD in the nervous system, TGF-beta-mediated retinal apoptosis in vitro and in vivo, and interactions of TGF-beta with other pro- and anti-apoptotic factors.

  13. Transformation of adrenal medullary chromaffin cells increases asthmatic susceptibility in pups from allergen-sensitized rats

    Directory of Open Access Journals (Sweden)

    Feng Jun-Tao

    2012-11-01

    Full Text Available Abstract Background Studies have shown that epinephrine release is impaired in patients with asthma. The pregnancy of female rats (dams with asthma promotes in their pups the differentiation of adrenal medulla chromaffin cells (AMCCs into sympathetic neurons, mediated by nerve growth factor, which leads to a reduction in epinephrine secretion. However, the relatedness between the alteration of AMCCs and increased asthma susceptibility in such offspring has not been established. Methods In this study, we observed the effects of allergization via ovalbumin on rat pups born of asthmatic dams. Results Compared to the offspring of untreated controls, bronchial hyperreactivity and airway inflammation were more severe in the pups from sensitized (asthmatic dams. In pups exposed to nerve growth factor (NGF in utero these effects were aggravated further, but the effects were blocked in pups whose dams had been treated with anti-NGF. Furthermore, alterations in AMCC phenotype corresponded to the degree of bronchial hyperreactivity and lung lesions of the different treatment groups. Such AMCC alterations included degranulation of chromaffin granules, reduction of epinephrine and phenylethanolamine-n-methyl transferase, and elevation of NGF and peripherin levels. Conclusions Our results present evidence that asthma during the pregnancy of rat dams promotes asthma susceptibility in their offspring, and that the transformation of AMCCs to neurons induced by NGF plays an important role in this process.

  14. Transformation of a Cutaneous Follicle Center Lymphoma to a Diffuse Large B-Cell Lymphoma—An Unusual Presentation

    Directory of Open Access Journals (Sweden)

    J. Dias Coelho

    2010-01-01

    Full Text Available Primary cutaneous follicle center lymphoma (PCFCL is characterized by a proliferation of follicle center cells in the skin. A definitive diagnosis is frequently delayed because of difficulties in interpretation of the histopathologic findings. It has an excellent prognosis with a 5-year survival over 95% and its risk of transformation has not been established. We describe a case report of man with a gastric diffuse large B-cell lymphoma (DLBCL referred to our clinic because of nodules in the back that had gradually developed over a period of 10 years. A biopsy performed 3 years before was interpreted as reactive follicular hyperplasia. A new skin biopsy revealed a diffuse large B-cell lymphoma and immunoglobulin heavy chain gene rearrangements from the initial skin biopsy (PCBCL and the DLBCL gastric biopsy were studied by polymerase chain reaction and an identical clonal rearrangement was detected which was highly suggestive of a transformation lymphoma.

  15. A tumor-promoting mechanism mediated by retrotransposon-encoded reverse transcriptase is active in human transformed cell lines.

    Science.gov (United States)

    Sciamanna, Ilaria; Gualtieri, Alberto; Cossetti, Cristina; Osimo, Emanuele Felice; Ferracin, Manuela; Macchia, Gianfranco; Aricò, Eleonora; Prosseda, Gianni; Vitullo, Patrizia; Misteli, Tom; Spadafora, Corrado

    2013-12-01

    LINE-1 elements make up the most abundant retrotransposon family in the human genome. Full-length LINE-1 elements encode a reverse transcriptase (RT) activity required for their own retrotranpsosition as well as that of non-autonomous Alu elements. LINE-1 are poorly expressed in normal cells and abundantly in cancer cells. Decreasing RT activity in cancer cells, by either LINE-1-specific RNA interference, or by RT inhibitory drugs, was previously found to reduce proliferation and promote differentiation and to antagonize tumor growth in animal models. Here we have investigated how RT exerts these global regulatory functions. We report that the RT inhibitor efavirenz (EFV) selectively downregulates proliferation of transformed cell lines, while exerting only mild effects on non-transformed cells; this differential sensitivity matches a differential RT abundance, which is high in the former and undetectable in the latter. Using CsCl density gradients, we selectively identify Alu and LINE-1 containing DNA:RNA hybrid molecules in cancer but not in normal cells. Remarkably, hybrid molecules fail to form in tumor cells treated with EFV under the same conditions that repress proliferation and induce the reprogramming of expression profiles of coding genes, microRNAs (miRNAs) and ultraconserved regions (UCRs). The RT-sensitive miRNAs and UCRs are significantly associated with Alu sequences. The results suggest that LINE-1-encoded RT governs the balance between single-stranded and double-stranded RNA production. In cancer cells the abundant RT reverse-transcribes retroelement-derived mRNAs forming RNA:DNA hybrids. We propose that this impairs the formation of double-stranded RNAs and the ensuing production of small regulatory RNAs, with a direct impact on gene expression. RT inhibition restores the 'normal' small RNA profile and the regulatory networks that depend on them. Thus, the retrotransposon-encoded RT drives a previously unrecognized mechanism crucial to the

  16. Chromosome 17p13.2 transfer reverts transformation phenotypes and Fas-mediated apoptosis in breast epithelial cells.

    Science.gov (United States)

    Lareef, Mohamed H; Tahin, Quivo; Song, Joon; Russo, Irma H; Mihaila, Dana; Slater, Carolyn M; Balsara, Binaifer; Testa, Joseph R; Broccoli, Dominique; Grobelny, Jennifer V; Mor, Gil; Cuthbert, Andrew; Russo, Jose

    2004-04-01

    Transformation of the human breast epithelial cells (HBEC) MCF-10F with the carcinogen benz(a)pyrene (BP) into BP1-E cells resulted in the loss of the chromosome 17 p13.2 locus (D17S796 marker) and formation of colonies in agar-methocel (colony efficiency (CE)), loss of ductulogenic capacity in collagen matrix, and resistance to anti-Fas monoclonal antibody (Mab)-induced apoptosis. For testing the role of that specific region of chromosome 17 in the expression of transformation phenotypes, we transferred chromosome 17 from mouse fibroblast donors to BP1-E cells. Chromosome 11 was used as negative control. After G418 selection, nine clones each were randomly selected from BP1-E-11neo and BP1-E-17neo hybrids, respectively, and tested for the presence of the donor chromosomes by fluorescent in situ hybridization and polymerase chain reaction-based restriction fragment length polymorphism (PCR-RFLP) analyses. Sensitivity to Fas Mab-induced apoptosis and evaluation of transformation phenotype expression were tested in MCF-10F, BP1-E, and nine BP1-E-11neo and BP1-E-17neo clones each. Six BP1-E-17neo clones exhibited a reversion of transformation phenotypes and a dose dependent sensitivity to Fas Mab-induced apoptosis, behaving similarly to MCF-10F cells. All BP1-E-11neo, and three BP1-E-17neo cell clones, like BP1-E cells, retained a high CE, loss of ductulogenic capacity, and were resistant to all Fas Mab doses tested. Genomic analysis revealed that those six BP1-E-17neo clones that were Fas-sensitive and reverted their transformed phenotypes had retained the 17p13.2 (D17S796 marker) region, whereas it was absent in all resistant clones, indicating that the expression of transformation phenotypes and the sensitivity of the cells to Fas-mediated apoptosis were under the control of genes located in this region. PMID:15057875

  17. High expression of pituitary tumor-transforming gene-1 predicts poor prognosis in clear cell renal cell carcinoma

    Science.gov (United States)

    WEI, CAN; YANG, XIAOLIANG; XI, JUNHUA; WU, WEI; YANG, ZHENXING; WANG, WEI; TANG, ZHIGUO; YING, QUANSHENG; ZHANG, YANBIN

    2015-01-01

    Pituitary tumor-transforming gene-1 (PTTG1) is a recently identified oncogene involved in the progression of malignant tumors; however, the expression level of PTTG1 in clear cell renal cell carcinoma (ccRCC) and its potential value as a novel prognostic marker for ccRCC remains unclear. In this study, PTTG1 mRNA and protein levels were assessed in 44 paired ccRCC tissues and adjacent normal tissues by quantitative polymerase chain reaction (qPCR) and immunohistochemistry, respectively. Further immunohistochemical analysis was implemented in 192 samples of ccRCC to evaluate the associations between PTTG1 levels and the clinical characteristics in ccRCC. Reverse transcription qPCR and immunohistochemical analysis demonstrated that the PTTG1 mRNA and protein levels were significantly higher in ccRCC compared to normal tissues. In addition, the PTTG1 protein level in 192 ccRCC samples was found to be significantly correlated with T stage, N classification, metastasis, recurrence and Fuhrman grade, whereas it was not associated with age and gender. Patients with low PTTG1 levels exhibited a better survival outcome compared to those with a higher PTTG1 level. PTTG1 expression and N stage were identified as independent prognostic factors for the overall survival of ccRCC patients. The results suggested that the overexpression of PTTG1 indicates a poor prognosis in ccRCC patients and, therefore, PTTG1 may serve as a novel prognostic marker for ccRCC. PMID:25798272

  18. Activity of interferon-dependent 2',5'-oligoadenylate synthetase in rat lymphoid cells under transformed environment conditions

    Science.gov (United States)

    Ostapchenko, L. I.; Mikhailik, I. V.; Prokopova, K. V.

    It is detected that interferon-dependent 2',5'-oligoadenylate synthetase is a sensitive index of immunocompetent cells functional state under transformed environment conditions. Microgravitation and ionising radiation induce increase of investigated enzyme activity in rat lymphocytes, which can be a result of lymphoid cells compensatory mechanisms starting in response to stress factors action. Administration of interferon inductors permits to stimulate the 2',5'-oligoadenylate synthetase, which enables one to correct pathological changes in the cells and to intensify adaptive reactions of immune systems.

  19. Monitoring of TGF-β 1-Induced Human Lung Adenocarcinoma A549 Cells Epithelial-Mesenchymal Transformation Process by Measuring Cell Adhesion Force with a Microfluidic Device.

    Science.gov (United States)

    Li, Yuan; Gao, AnXiu; Yu, Ling

    2016-01-01

    The epithelial-mesenchymal transition (EMT) is a process in which epithelial cells lose their cell polarity and cell-cell adhesion, and gain migratory and invasive properties. It is believed that EMT is associated with initiation and completion of the invasion-metastasis cascade. In this study, an economic approach was developed to fabricate a microfluidic device with less instrumentation requirement for the investigation of EMT by quantifying cell adhesion force. Fluid shear force was precisely controlled by a homemade microfluidic perfusion apparatus and interface. The adhesion capability of the human lung adenocarcinoma cell line A549 on different types of extracellular matrix protein was studied. In addition, effects of transforming growth factor-β (TGF-β) on EMT in A549 cells were investigated by characterizing the adhesion force changes and on-chip fluorescent staining. The results demonstrate that the microfluidic device is a potential tool to characterize the epithelial-mesenchymal transition process by measuring cell adhesion force.

  20. Interleukin-8 (IL-8) over-production and autocrine cell activation are key factors in monomethylarsonous acid [MMA(III)]-induced malignant transformation of urothelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Escudero-Lourdes, C., E-mail: cescuder@uaslp.mx [Centro de Investigación y Estudios de Posgrado (CIEP), Facultad de Ciencias Químicas, Universidad Autónoma de San Luis Potosí (Mexico); Wu, T.; Camarillo, J.M.; Gandolfi, A.J. [Department of Pharmacology and Toxicology College of Pharmacy, University of Arizona. Tucson, AZ (United States)

    2012-01-01

    The association between chronic human exposure to arsenicals and bladder cancer development is well recognized; however, the underlying molecular mechanisms have not been fully determined. We propose that inflammatory responses can play a pathogenic role in arsenic-related bladder carcinogenesis. In previous studies, it was demonstrated that chronic exposure to 50 nM monomethylarsenous acid [MMA(III)] leads to malignant transformation of an immortalized model of urothelial cells (UROtsa), with only 3 mo of exposure necessary to trigger the transformation-related changes. In the three-month window of exposure, the cells over-expressed pro-inflammatory cytokines (IL-1β, IL-6 and IL-8), consistent with the sustained activation of NFKβ and AP1/c-jun, ERK2, and STAT3. IL-8 was over-expressed within hours after exposure to MMA(III), and sustained over-expression was observed during chronic exposure. In this study, we profiled IL-8 expression in UROtsa cells exposed to 50 nM MMA(III) for 1 to 5 mo. IL-8 expression was increased mainly in cells after 3 mo MMA(III) exposure, and its production was also found increased in tumors derived from these cells after heterotransplantation in SCID mice. UROtsa cells do express both receptors, CXCR1 and CXCR2, suggesting that autocrine cell activation could be important in cell transformation. Supporting this observation and consistent with IL-8 over-expression, CXCR1 internalization was significantly increased after three months of exposure to MMA(III). The expression of MMP-9, cyclin D1, bcl-2, and VGEF was significantly increased in cells exposed to MMA(III) for 3 mo, but these mitogen-activated kinases were significantly decreased after IL-8 gene silencing, together with a decrease in cell proliferation rate and in anchorage-independent colony formation. These results suggest a relevant role of IL-8 in MMA(III)-induced UROtsa cell transformation. -- Highlights: ► IL-8 is over-expressed in human MMA(III)-exposed urothelial

  1. Transformation of Sézary syndrome into CD30+ anaplastic large T-cell lymphoma after alemtuzumab therapy with evidence of clonal unity.

    Science.gov (United States)

    Nevet, Mariela Judith; Zuckerman, Tsila; Sahar, Dvora; Bergman, Reuven

    2015-01-01

    Alemtuzumab is a humanized mouse antibody targeting the CD52 cell surface, which has been effective in patients with advanced stage mycosis fungoides (MF) including erythrodermic MF and Sézary syndrome. There are a few descriptions of large cell transformation after its administration. A young patient with an acute onset of Sézary syndrome treated initially unsuccessfully with fludarabine and cyclophosphamide and later on successfully with alemtuzumab has been described. Three weeks after the beginning of therapy, however, she developed transformed T-cell lymphoma indistinguishable from CD30 anaplastic large-cell lymphoma. After bone marrow transplantation, the transformed CD30 cutaneous T-cell lymphoma recurred as a transformed CD30 plaque MF. All 3 types of lesions showed the same T-cell receptor clonal gene rearrangement, which supports the notion that Sézary syndrome, CD30 anaplastic large-cell lymphoma, and MF are interrelated.

  2. Human papilloma virus transformed CaSki cells constitutively express high levels of functional SerpinB2.

    Science.gov (United States)

    Major, Lee; Schroder, Wayne A; Gardner, Joy; Fish, Richard J; Suhrbier, Andreas

    2011-02-01

    Many malignant tissues, including human papilloma virus (HPV)-associated cancers, express SerpinB2, also known as plasminogen activator inhibitor type-2 (PAI-2). Whether SerpinB2 is expressed by the HPV-transformed cancer cells, and if so, whether SerpinB2 is mutated or behaves aberrantly remains unclear. Here we show that HPV-transformed CaSki cells express high levels of constitutive wild-type SerpinB2, with cellular distribution, glycosylation, secretion, cleavage, induction and urokinase binding similar to that reported for primary cells. Neutralization of secreted SerpinB2 failed to affect CaSki cell migration or growth. Lentivirus-based over-expression of SerpinB2 also had no effect on growth, and we were unable to confirm a role for SerpinB2 in binding or regulating expression of the retinoblastoma protein. CaSki cells thus emerge as a useful tool for studying SerpinB2, with the physiological function of SerpinB2 expression by tumor cells remaining controversial. Using CaSki cells as a source of endogenous SerpinB2, we confirmed that SerpinB2 efficiently binds the proteasomal subunit member β1. PMID:20974129

  3. Organelle transformation.

    Science.gov (United States)

    Bhattacharya, Anjanabha; Kumar, Anish; Desai, Nirali; Parikh, Seema

    2012-01-01

    The source of genetic information in a plant cell is contained in nucleus, plastids, and mitochondria. Organelle transformation is getting a lot of attention nowadays because of its superior performance over the conventional and most commonly used nuclear transformation for obtaining transgenic lines. Absence of gene silencing, strong predictable transgene expression, and its application in molecular pharming, both in pharmaceutical and nutraceuticals, are some of many advantages. Other important benefits of utilizing this technology include the absence of transgene flow, as organelles are maternally inherited. This may increase the acceptability of organelle transformation technology in the development of transgenic crops in a wider scale all over the globe. As the need for crop productivity and therapeutic compounds increases, organelle transformation may be able to bridge the gap, thereby having a definite promise for the future. PMID:22610643

  4. Organelle transformation.

    Science.gov (United States)

    Bhattacharya, Anjanabha; Kumar, Anish; Desai, Nirali; Parikh, Seema

    2012-01-01

    The source of genetic information in a plant cell is contained in nucleus, plastids, and mitochondria. Organelle transformation is getting a lot of attention nowadays because of its superior performance over the conventional and most commonly used nuclear transformation for obtaining transgenic lines. Absence of gene silencing, strong predictable transgene expression, and its application in molecular pharming, both in pharmaceutical and nutraceuticals, are some of many advantages. Other important benefits of utilizing this technology include the absence of transgene flow, as organelles are maternally inherited. This may increase the acceptability of organelle transformation technology in the development of transgenic crops in a wider scale all over the globe. As the need for crop productivity and therapeutic compounds increases, organelle transformation may be able to bridge the gap, thereby having a definite promise for the future.

  5. Effect of transforming growth factor beta and bone morphogenetic proteins on rat hepatic stellate cell proliferation and trans-differentiation

    Institute of Scientific and Technical Information of China (English)

    Hong Shen; Guo-Jiang Huang; Yue-Wen Gong

    2003-01-01

    AIM: To explore different roles of TGF-β (transforming growth factor beta) and bone morphogenetic proteins (BMPs)in hepatic stellate cell proliferation and trans-differentiation.METHODS: Hepatic stellate cells were isolated from male Sprague-Dawley rats. Sub-cultured hepatic stellate cells were employed for cell proliferation assay with WST-1 reagent and Western blot analysis with antibody against smooth muscle alpha actin (SMA).RESULTS: The results indicated that TGF-β1 significantly inhibited cell proliferation at concentration as low as 0.1 ng/ml, but both BMP-2 and BMP-4 did not affect cell proliferation at concentration as high as 10 ng/ml. The effect on hepatic stellate cell trans-differentiation was similar between TGFβ1 and BMPs. However, BMPs was more potent at transdifferentiation of hepatic stellate cells than TGF-β1. In addition, we observed that TGF-β1 transient reduced the abundance of SMA in hepatic stellate cells.CONCLUSION: TGF-β may be more important in regulation of hepatic stellate cell proliferation while BMPs may be the major cytokines regulating hepatic stellate cell transdifferentiation.

  6. Study of immortalization and malignant transformation of human embryonic esophageal epithelial cells induced by HPV18 E6E7.

    Science.gov (United States)

    Shen, Z; Cen, S; Shen, J; Cai, W; Xu, J; Teng, Z; Hu, Z; Zeng, Y

    2000-10-01

    In order to study the effect of viruses and tumor promoters on the tumorigenicity of the esophagus, human embryonic esophageal epithelial cells were infected with human papilloma virus HPV18 E6E7-AAV in synergy with 12-O-tetradecanoylphorbol 13-acetate (TPA) to observe their malignant transformation. The cultured esophageal epithelial cells incubated with HPV18 E6E7-AAV were divided into two groups: the SHEEC1 group was exposed to TPA (5 ng/ml) for 4 weeks at the 5th passage of the cells; the SHEE group served as the control and was cultured in the same medium without TPA. The morphological phenotype, the DNA content during the cell cycle and the chromosomes were analyzed. The tumorigenicity was assessed by colony formation after cultivation in soft agar and transplanting the cells into nude mice. HPV18 E6E7 DNA was assayed by fluorescent in situ hybridization (FISH) and the polymerase chain reaction (PCR). The SHEE group, at its 20th passage, grew as a monolayer with the cells showing anchorage dependence and contact inhibition. The chromosome analysis showed diploidy, and soft-agar cultivation and injection into nude mice showed the cells to be non-tumorigenic. They were therefore immortalized cells. In contrast, the SHEEC1 group (TPA group) showed increased DNA synthesis and a proliferative index that was higher (45%) than that of the SHEE group (34%). The number of large colonies of dense multilayer cells (positively transformed foci) in soft agar was high in SHEEC1 group (4.0%) but low in the SHEE group (0.1%). Tumors resulting from transplantation were observed in all six nude mice injected subcutaneously with cells of the SHEEC1 group but no tumor developed in mice receiving cells of the SHEE group. In both groups of cells, HPV18 E6E7 DNA was positively detected by FISH and PCR. The malignant transformation of human embryonic epithelial cells was induced in vitro by HPV18 E6E7 in synergy with TPA. This is a good evidence for the close relationship between

  7. COMBINED USE OF FOURIER TRANSFORM INFRARED AND RAMAN SPECTROSCOPY TO STUDY PLANKTONIC AND BIOFILM CELLS OF CRONOBACTER SAKAZAKII

    Directory of Open Access Journals (Sweden)

    Garima Sharma

    2014-02-01

    Full Text Available Cronobacter sakazakii is an opportunistic pathogen, which causes necrotizing enterocolitis, bacteriaemia and infant meningitis. It has the ability to form biofilm on food contact surfaces, creating food safety risks. In this work, the phenotypic expression of planktonic and biofilm was studied by Fourier transform infrared (FTIR and Raman spectroscopy. FTIR spectra of the biofilm cells exhibited higher intensity in the absorption bands assigned to polysaccharides, amide I, amide II vibrational mode of ester and carboxylate group. Raman spectra of the biofilm cells showed higher intensity in the absorption band assigned to tyrosine, amide III, carbohydrates, carotenoids, DNA and lipids. Understanding the chemical properties of planktonic and biofilm cells employing the two techniques helped to decipher the differences in the chemical composition between planktonic and biofilm cells. This can promote a better understanding of the persistence, survival and resistance of the biofilm cells.

  8. Abnormal promoter methylation of multiple genes in the malignant transformed PEP2D cells induced by alpha particles exposure

    Institute of Scientific and Technical Information of China (English)

    LiP; SuiJL

    2002-01-01

    The 5' promoter regions of some genes contain CpG-rich areas,known as CpG islands,Methylation of the cytosine in these dinuleotides has important regulatory effects on gene expression.The functional significance of promoter hypermethylation would play the same roles in carcinogenesis as gene mutations.The promoter methylations p14ARF,p16INK4a,MGMT,GSTP1,BUB3 and DAPK genes were analyzed with methylation specific PCR(MSP) in the transformed human bronchial epithelial cells(BEP2D) induced by α-particles.The results indicated that p14ARF gene was not methylated in BEP2D cells,but was methylated in the malignant transformed BERP35T-1 cells,and the level of its transcription was depressed remarkable in the latter.However p16INK4a gene,which shares two exons with p14ARF gene,was not methylated.MGMT gene was methylated in both BEP2D and BERP35T-1.DAPK gene was partially methylated in BEP2D cells and methylated completely in BERP35T1.GSTP1 was not methylated in BEP2D cells and was methylated partly in BERP35T-1.BUB3 gene was not methylated in BEP2D as well as BERP35T1 cells and was further proved by sequencing analysis.

  9. Over-expressed Genes Detected by Suppression Subtractive Hybridization in Carcinoma Derived From Transformed 16HBE Cells Induced by BPDE

    Institute of Scientific and Technical Information of China (English)

    SHE-JUAN AN; JIA-KUN CHEN; LI-LI LIU; YAN-FENG ZHAO; XUE-MIN CHEN

    2005-01-01

    Objective To screen the over differentially expressed genes in carcinoma induced by BPDE-transformed 16HBE cells (16HBE-C cells). Methods The suppression subtractive hybridization (SSH) method was performed to profile differentially expressed genes between 16HBE-C cells and 16HBE cells. The cDNA fragments of differentially expressed genes were inserted into TA cloning vector and transformed competent E. coli strain. Positive clones were randomly picked up and identified by the colony PCR method. Dot blot was used to test the same source with the tester. The differentially expressed cDNA fragments were sequenced and compared with known genes and EST database in Genbank. Results Eight known genes were over-expressed in 16HBE-C cells including eukaryotic translation elongation factor 1 alpha 1, HIF-1 responsive RTP801, ribosomal protein L10 (RPL10), ribosomal protein S29 (RPS29), mitochondrion related genes, and laminin receptor 1. Three differentially expressed cDNA fragments could not be matched to the known genes but to the EST database. Conclusion The SSH method can detect differentially expressed genes between 16HBE-C and 16HBE cells. BPDE-induced carcinogenesis may be related to alteration of at least eight known genes and three unknown genes. These expression data provide a clue to further cloning novel genes and studying functions in BPDE-induced carcinoma.

  10. Immortality, but not oncogenic transformation, of primary human cells leads to epigenetic reprogramming of DNA methylation and gene expression

    OpenAIRE

    Gordon, Katrina; Clouaire, Thomas; Bao, Xun X.; Kemp, Sadie E.; Xenophontos, Maria; de Las Heras, Jose Ignacio; Stancheva, Irina

    2013-01-01

    Tumourigenic transformation of normal cells into cancer typically involves several steps resulting in acquisition of unlimited growth potential, evasion of apoptosis and non-responsiveness to growth inhibitory signals. Both genetic and epigenetic changes can contribute to cancer development and progression. Given the vast genetic heterogeneity of human cancers and difficulty to monitor cancer-initiating events in vivo, the precise relationship between acquisition of genetic mutations and the ...

  11. 5-Azacytidine treatment of HA-A melanoma cells induces Sp1 activity and concomitant transforming growth factor alpha expression.

    OpenAIRE

    Shin, T H; Paterson, A. J.; Grant, J H; Meluch, A A; Kudlow, J E

    1992-01-01

    Evidence indicates DNA methylation as a part of the regulatory machinery controlling mammalian gene expression. The human melanoma cell line HA-A expresses low levels of transforming growth factor alpha (TGF-alpha). TGF-alpha mRNA accumulated, however, in response to DNA demethylation induced by a nucleoside analog, 5-azacytidine (5-azaC). The importance of DNA methylation in the TGF-alpha promoter region was examined by a transient transfection assay with luciferase reporter plasmids contain...

  12. The ETS Transcription Factor ESE-1 Transforms MCF-12A Human Mammary Epithelial Cells via a Novel Cytoplasmic Mechanism

    OpenAIRE

    Prescott, Jason D.; Koto, Karen S. N.; Singh, Meenakshi; Gutierrez-Hartmann, Arthur

    2004-01-01

    Several different transcription factors, including estrogen receptor, progesterone receptor, and ETS family members, have been implicated in human breast cancer, indicating that transcription factor-induced alterations in gene expression underlie mammary cell transformation. ESE-1 is an epithelium-specific ETS transcription factor that contains two distinguishing domains, a serine- and aspartic acid-rich (SAR) domain and an AT hook domain. ESE-1 is abundantly expressed in human breast cancer ...

  13. Noncanonical transforming growth factor β (TGFβ) signaling in cranial neural crest cells causes tongue muscle developmental defects.

    Science.gov (United States)

    Iwata, Jun-ichi; Suzuki, Akiko; Pelikan, Richard C; Ho, Thach-Vu; Chai, Yang

    2013-10-11

    Microglossia is a congenital birth defect in humans and adversely impacts quality of life. In vertebrates, tongue muscle derives from the cranial mesoderm, whereas tendons and connective tissues in the craniofacial region originate from cranial neural crest (CNC) cells. Loss of transforming growth factor β (TGFβ) type II receptor in CNC cells in mice (Tgfbr2(fl/fl);Wnt1-Cre) causes microglossia due to a failure of cell-cell communication between cranial mesoderm and CNC cells during tongue development. However, it is still unclear how TGFβ signaling in CNC cells regulates the fate of mesoderm-derived myoblasts during tongue development. Here we show that activation of the cytoplasmic and nuclear tyrosine kinase 1 (ABL1) cascade in Tgfbr2(fl/fl);Wnt1-Cre mice results in a failure of CNC-derived cell differentiation followed by a disruption of TGFβ-mediated induction of growth factors and reduction of myogenic cell proliferation and differentiation activities. Among the affected growth factors, the addition of fibroblast growth factor 4 (FGF4) and neutralizing antibody for follistatin (FST; an antagonist of bone morphogenetic protein (BMP)) could most efficiently restore cell proliferation, differentiation, and organization of muscle cells in the tongue of Tgfbr2(fl/fl);Wnt1-Cre mice. Thus, our data indicate that CNC-derived fibroblasts regulate the fate of mesoderm-derived myoblasts through TGFβ-mediated regulation of FGF and BMP signaling during tongue development.

  14. Molecular Tissue Engineering:Applications for Modulation of Mesenchymal Stem Cells Proliferation by Transforming Growth Factor

    Institute of Scientific and Technical Information of China (English)

    GUO; Xiaodong(

    2001-01-01

    [1]郭晓东 杜靖远 郑启新等.组织工程学技术修复关节软骨缺损研究进展.国外医学生物医学工程分册 2000 23(6):330[2]郭晓东 杜靖远 郑启新等.骨关节炎基因治疗进展.国外医学老年医学分册 2001 22(1):29[3]Grande D Breitbart A Mason J et al.Cartilage tissue engineering:current limitations and solutions.Clin Orthop 1999 367S:S176[4]Brittberg M Lindahl A Nilsson A et al.Treatment of deep cartilage defects in the knee with autologous chondrocyte transplantation.N Engl J Med 1994 331:889[5]Reddi A.Morphogenesis and tissue engineering of bone and cartilage:inductive signals stem cells and biomimetic biomaterials.Tissue Eng 2000 6(4) :351[6]Freed L Martin I Vunjak-Novakovic G.Frontiers in tissue engineering:in vitro modulation of chondrogene sis.Clin Orthop 1999 367S:S46[7]Evans C Ghivizzani S Smith P et al.Using gene therapy to protect and restore cartilage.Clin Orthop 2000 379 (Suppl) :S214[8]Fernandes J Martel-Pelletier J Pelletier J.Gene therapy for osteoarthritis:new perspectives for the twentyfirst century.Clin Orthop 2000 379(Suppl):S262[9]Mason J M Breitbart A S Barcia M et al.Cartilage and bone regeneration using gene-enhanced tissue engineering.Clin Orthop 2000 379 (Suppl):S171[10]郭晓东 杜靖远 郑启新等.分子生物学在组织工程学研究中的应用前景.中华实验外科杂志 2001 18(3):283[11]郭晓东 全大萍.组织工程与生物材料.见:生物医用材料导论.李世普主编.武汉:武汉工业大学出版社 2000.302[12]Liu Y Zheng Q X Du J Y et al.Cloning and expression of rat transforming growth factorβ1 cDNA in osteoblasts.J Tongji Med Univ 2000 20:63[13]Johnstone B Yoo J.Autologous mesenchymal progenitol cells in articular cartilage repair.Clin Orthop 1999 367S:S156[14]Yoo J Mandell I Angele P et al.Chondrogenitor cells and gene therapy.Clin Orthop 2000 379 (Suppl):S164[15]Caplan A I.Mesenchymal stem cells and gene

  15. Inhibition of Protease-Resistant Prion Protein Formation in a Transformed Deer Cell Line Infected with Chronic Wasting Disease‡

    Science.gov (United States)

    Raymond, Gregory J.; Olsen, Emily A.; Lee, Kil Sun; Raymond, Lynne D.; Bryant, P. Kruger; Baron, Gerald S.; Caughey, Winslow S.; Kocisko, David A.; McHolland, Linda E.; Favara, Cynthia; Langeveld, Jan P. M.; van Zijderveld, Fred G.; Mayer, Richard T.; Miller, Michael W.; Williams, Elizabeth S.; Caughey, Byron

    2006-01-01

    Chronic wasting disease (CWD) is an emerging transmissible spongiform encephalopathy (prion disease) of North American cervids, i.e., mule deer, white-tailed deer, and elk (wapiti). To facilitate in vitro studies of CWD, we have developed a transformed deer cell line that is persistently infected with CWD. Primary cultures derived from uninfected mule deer brain tissue were transformed by transfection with a plasmid containing the simian virus 40 genome. A transformed cell line (MDB) was exposed to microsomes prepared from the brainstem of a CWD-affected mule deer. CWD-associated, protease-resistant prion protein (PrPCWD) was used as an indicator of CWD infection. Although no PrPCWD was detected in any of these cultures after two passes, dilution cloning of cells yielded one PrPCWD-positive clone out of 51. This clone, designated MDBCWD, has maintained stable PrPCWD production through 32 serial passes thus far. A second round of dilution cloning yielded 20 PrPCWD-positive subclones out of 30, one of which was designated MDBCWD2. The MDBCWD2 cell line was positive for fibronectin and negative for microtubule-associated protein 2 (a neuronal marker) and glial fibrillary acidic protein (an activated astrocyte marker), consistent with derivation from brain fibroblasts (e.g., meningeal fibroblasts). Two inhibitors of rodent scrapie protease-resistant PrP accumulation, pentosan polysulfate and a porphyrin compound, indium (III) meso-tetra(4-sulfonatophenyl)porphine chloride, potently blocked PrPCWD accumulation in MDBCWD cells. This demonstrates the utility of these cells in a rapid in vitro screening assay for PrPCWD inhibitors and suggests that these compounds have potential to be active against CWD in vivo. PMID:16378962

  16. Expression of hIGF-I in the silk glands of transgenic silkworms and in transformed silkworm cells

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    To express human insulin-like growth factor-I (hIGF-I) in transformed Bombyx mori cultured cells and silk glands, the transgenic vector pigA3GFP-hIGF-ie-neo was constructed with a neomycin resistance gene driven by the baculovirus ie-1 promoter, and with the hIGF-I gene under the control of the silkworm sericin promoter Ser-1. The stably transformed BmN cells expressing hIGF-I were selected by using the antibiotic G418 at a final concentration of 700-800 μg/mL after the BmN cells were transfected with the piggyBac vector and the helper plasmid. The specific band of hIGF-I was detected in the transformed cells by Western blot. The expression level of hIGF-I, determined by ELISA, was about 7800 pg in 5×105 cells. Analysis of the chromosomal insertion sites by inverse PCR showed that exogenous DNA could be inserted into the cell genome randomly or at TTAA target sequence specifically for piggyBac element transposition. The transgenic vector pigA3GFP-hIGF-ie-neo was transferred into the eggs using sperm-mediated gene transfer. Finally, two transgenic silkworms were obtained after screening for the neo and gfp genes and verified by PCR and dot hybridization. The expression level of hIGF-I determined by ELISA was about 2440 pg/g of silk gland of the transgenic silkworms of the G1 generation.

  17. Extraction of Nucleolus Candidate Zone in White Blood Cells of Peripheral Blood Smear Images Using Curvelet Transform

    Directory of Open Access Journals (Sweden)

    Ramin Soltanzadeh

    2012-01-01

    Full Text Available The main part of each white blood cell (WBC is its nucleus which contains chromosomes. Although white blood cells (WBCs with giant nuclei are the main symptom of leukemia, they are not sufficient to prove this disease and other symptoms must be investigated. For example another important symptom of leukemia is the existence of nucleolus in nucleus. The nucleus contains chromatin and a structure called the nucleolus. Chromatin is DNA in its active form while nucleolus is composed of protein and RNA, which are usually inactive. In this paper, to diagnose this symptom and in order to discriminate between nucleoli and chromatins, we employ curvelet transform, which is a multiresolution transform for detecting 2D singularities in images. For this reason, at first nuclei are extracted by means of K-means method, then curvelet transform is applied on extracted nuclei and the coefficients are modified, and finally reconstructed image is used to extract the candidate locations of chromatins and nucleoli. This method is applied on 100 microscopic images and succeeds with specificity of 80.2% and sensitivity of 84.3% to detect the nucleolus candidate zone. After nucleolus candidate zone detection, new features that can be used to classify atypical and blast cells such as gradient of saturation channel are extracted.

  18. The impact of metformin and salinomycin on transforming growth factor β-induced epithelial-to-mesenchymal transition in non-small cell lung cancer cell lines

    Science.gov (United States)

    KOECK, STEFAN; AMANN, ARNO; HUBER, JULIA M.; GAMERITH, GABRIELE; HILBE, WOLFGANG; ZWIERZINA, HEINZ

    2016-01-01

    The epithelial-to-mesenchymal transition (EMT) is highly involved in the development of metastases. EMT transforms epithelial carcinoma cells into mesenchymal-like cells, characterized by increased cell migration and invasiveness. Transforming growth factor β (TGFβ) appears to be crucial in this process. Metformin and salinomycin have demonstrated an EMT inhibitory effect. The current experiments indicate that these substances specifically inhibit TGFβ-induced EMT in non-small cell lung cancer (NSCLC) cell lines. The NSCLC cell lines A549 and HCC4006 were stimulated with TGFβ for 48 h to induce EMT. Metformin or salinomycin was added simultaneously with TGFβ to inhibit TGFβ-induced EMT. Western blot analyses of E-cadherin and vimentin were performed to detect changes in EMT marker expression, and a wound healing assay was conducted to determine the potential effects on cell migration. The effects of the two drugs on cell viability were also investigated using MTS tetrazolium dye assays. The results revealed that cells undergoing EMT by application of TGFβ exhibited a downregulation of E-cadherin and an upregulation of vimentin protein expression on western blot analyses, and an increased capacity for cell migration. Simultaneous application of TGFβ and metformin specifically inhibited EMT and increased E-cadherin expression. At the higher dose tested, salinomycin also inhibited EMT, despite an increase in vimentin expression in the two cell lines. Furthermore, metformin and salinomycin, at the two concentrations tested, inhibited cell migration. These findings demonstrate that metformin and salinomycin are able to block EMT and inhibit EMT-induced cell migration. Thus, these two substances are novel EMT inhibiting drugs that have the potential to specifically control EMT and metastatic spread in NSCLC. PMID:27073581

  19. Autophagy-deficiency in hepatic progenitor cells leads to the defects of stemness and enhances susceptibility to neoplastic transformation.

    Science.gov (United States)

    Xue, Feng; Hu, Lei; Ge, Ruiliang; Yang, Lixue; Liu, Kai; Li, Yunyun; Sun, Yanfu; Wang, Kui

    2016-02-01

    Autophagy is a highly conserved and lysosome-dependent degradation process which assists in cell survival and tissue homeostasis. Although previous reports have shown that deletion of the essential autophagy gene disturbs stem cell maintenance in some cell types such as hematopoietic and neural cells, it remains unclear how autophagy-deficiency influences hepatic progenitor cells (HPCs). Here we report that Atg5-deficiency in HPCs delays HPC-mediated rat liver regeneration in vivo. In vitro researches further demonstrate that loss of autophagy decreases the abilities of colony and spheroid formations, and disrupts the induction of hepatic differentiation in HPCs. Meanwhile, autophagy-deficiency increases the accumulations of damaged mitochondria and mitochondrial reactive oxygen species (mtROS) and suppresses homologous recombination (HR) pathway of DNA damage repair in HPCs. Moreover, in both diethylnitrosamine (DEN) and CCl4 models, autophagy-deficiency accelerates neoplastic transformation of HPCs. In conclusion, these findings demonstrate that autophagy contributes to stemness maintenance and reduces susceptibility to neoplastic transformation in HPCs.

  20. Increased frequency of spontaneous neoplastic transformation in progeny of bystander cells from cultures exposed to densely ionizing radiation.

    Directory of Open Access Journals (Sweden)

    Manuela Buonanno

    Full Text Available An increased risk of carcinogenesis caused by exposure to space radiation during prolonged space travel is a limiting factor for human space exploration. Typically, astronauts are exposed to low fluences of ionizing particles that target only a few cells in a tissue at any one time. The propagation of stressful effects from irradiated to neighboring bystander cells and their transmission to progeny cells would be of importance in estimates of the health risks of exposure to space radiation. With relevance to the risk of carcinogenesis, we investigated, in model C3H 10T½ mouse embryo fibroblasts (MEFs, modulation of the spontaneous frequency of neoplastic transformation in the progeny of bystander MEFs that had been in co-culture 10 population doublings earlier with MEFs exposed to moderate doses of densely ionizing iron ions (1 GeV/nucleon or sparsely ionizing protons (1 GeV. An increase (P<0.05 in neoplastic transformation frequency, likely mediated by intercellular communication through gap junctions, was observed in the progeny of bystander cells that had been in co-culture with cells irradiated with iron ions, but not with protons.

  1. The Transformations of Transformations.

    Science.gov (United States)

    Lin, Francis Y.

    2000-01-01

    Harris's original idea of transformations has been changed several times in Chomsky's work. This article explicates these transformations, arguing that though their motivations are highly understandable, these transformations are not necessary for understanding the workings of natural languages. (Author/VWL)

  2. Fourier transform Raman spectroscopic characterisation of cells of the plant-associated soil bacterium Azospirillum brasilense Sp7

    Science.gov (United States)

    Kamnev, A. A.; Tarantilis, P. A.; Antonyuk, L. P.; Bespalova, L. A.; Polissiou, M. G.; Colina, M.; Gardiner, P. H. E.; Ignatov, V. V.

    2001-05-01

    Structural and compositional features of bacterial cell samples and of lipopolysaccharide-protein complex isolated from the cell surface of the plant-growth-promoting rhizobacterium Azospirillum brasilense (wild-type strain Sp7) were characterised using Fourier transform (FT) Raman spectroscopy. The structural spectroscopic information obtained is analysed and considered together with analytical data on the content of metal cations (Co 2+, Cu 2+ and Zn 2+) in the bacterial cells grown in a standard medium as well as in the presence of each of the cations (0.2 mM). The latter, being taken up by bacterial cells from the culture medium in significant amounts, were shown to induce certain metabolic changes in the bacterium revealed in FT-Raman spectra, which is discussed from the viewpoint of bacterial response to environmental stresses.

  3. UVB-Radiation-Induced Apoptosis in Jurkat Cells: A Coordinated Fourier Transform Infrared Spectroscopy-Flow Cytometry Study

    CERN Document Server

    Pozzi, Deleana; Gaudenzi, Silvia; Di Giambattista, Lucia; Silvestri, Ida; Morrone, Stefania; Castellano, Agostina Congiu

    2010-01-01

    We studied the induction of apoptosis in Jurkat cells by UVB radiation (wavelength 290-320 nm) at a dose of 310 mJ/cm^2. We combined Fourier transform infrared (FTIR) spectroscopy with flow cytometry to determine whether the combination of both techniques could provide new and improved information about cell modifications. To do this, we looked for correspondences and correlations between spectroscopy and flow cytometry data and found three highly probable spectroscopic markers of apoptosis. The behavior of the wave number shift of both the Amide I beta-sheet component and the area of the 1083 cm^-1 band reproduced, with a high correlation, the behavior of the early apoptotic cell population, while the behavior of the Amide I area showed a high correlation with the early plus late apoptotic cell population.

  4. Strain-dependent susceptibility to radiation-induced mammary cancer is a result of differences in epithelial cell sensitivity to transformation.

    Science.gov (United States)

    Ullrich, R L; Bowles, N D; Satterfield, L C; Davis, C M

    1996-09-01

    Variations in sensitivity to radiation-induced mammary cancer among different strains of mice are well known. However, the reasons for these variations have not been determined. In the present study, the cell dissociation assay was used to determine the radiation-induced transformation frequencies in sensitive BALB/c mice and resistant C57BL mice as well as the resistant hybrid B6CF1 independent of host environment. The influence of host environment on the progression of transformed cells to the neoplastic phenotype was also examined. Results demonstrated that the variations in sensitivity among these sensitive and resistant mice are a result of inherent differences in the sensitivity of the mammary epithelial cells to radiation-induced transformation. Under the conditions used, host environment played no role in the initiation of transformed cells by radiation or in the progression of these cells to the neoplastic phenotype.

  5. Strain-dependent susceptibiltiy to radiation-induced mammary cancer is a result of differences in epithelial cell sensitivity to transformation

    Energy Technology Data Exchange (ETDEWEB)

    Ullrich, R.L.; Davis, C.M. [Univ. of Texas Medical Branch, Galveston, TX (United States); Bowles, N.D.; Satterfield, L.C. [Oak Ridge National Lab., Oak Ridge, TN (United States)

    1996-09-01

    Variations in sensitivity to radiation-induced mammary cancer among different strains of mice are well known. However, the reasons for these variations have not been determined. In the present study, the cell dissociation assay was used to determine the radiation-induced transformation frequencies in sensitive BALB/c mice and resistant C57BL mice as well as the resistant hybrid B6Cf{sub 1} independent of host environment. The influence of host environment on the progression of transformed cells to the neoplastic phenotype was also examined. Results demonstrated that the variations in sensitivity among these sensitive and resistant mice are a result of inherent differences in the sensitivity of the mammary epithelial cells to radiation-induced transformation. Under the conditions used, host environment played no role in the initiation of transformed cells by radiation or in the progression of these cells to the neoplastic phenotype. 19 refs., 1 tab.

  6. Phenotype transformation of immortalized NCM460 colon epithelial cell line by TGF-β1 is associated with chromosome instability.

    Science.gov (United States)

    Huang, Chao; Wen, Bin

    2016-10-01

    Transforming growth factor-β1 (TGF-β1) within tumor microenvironment has a pivotal function in cancer initiation and tumorigenesis, and hence this study was to observe the malignant transformation induced by TGF-β1 in an immortalized colon epithelial cell line NCM460 for better understanding the mechanisms of colon carcinogenesis. Immortalized colon epithelial cell line NCM460 was used as the model of this study, and was treated with different concentrations of TGF-β1 for different time. Then, immunofluorescence was performed to observe the change of phenotype hallmarks including adherent junction protein E-cadherin, cytoskeleton protein vimentin, and tight junction marker ZO-1, western blotting analysis was performed to detect the expression of the above three markers and two transcription factors (Snail and Slug) involved in the transformation by TGF-β1. In addition, chromosome instability (CHI) including analysis of DNA-ploid was detected by flow cytometry. Our results revealed significant loss or reduction of ZO-1 and E-cadherin, and robust emergence of vimentin in the cell line NCM460 after a 15-, 20-, and 25-day treatment with 10 ng/ml TGF-β1. Interestingly, 20 and 25 days after stimulation with 5 ng/ml TGF-β1, expression of E-cadherin and ZO-1 revealed a pattern roughly similar to that of 10 ng/ml TGF-β1, especially, both expressions was vanished and vimentin expression was dramatically increased at days 25 after TGF-β1 stimulation. After a stimulation with 10 ng/ml TGF-β1 for 15, 20, and 25 days, the levels of Snail and Slug expression in the cells were significantly up-regulated, compared with the cells treated with TGF-β1 inhibitor LY364947, PBS or balnk control (P TGF-β1 after its stimulation for 15, 20, and 25 days. Very few mitotic cells with treatment of PBS for 15, 20 and 25 days were non-diploid whose DNA content was greater or less than 4 N, but these cells were significantly increased after exposure to TGF-β1 for 15, 20, and

  7. A new process for obtaining hydroxytyrosol using transformed Escherichia coli whole cells with phenol hydroxylase gene from Geobacillus thermoglucosidasius.

    Science.gov (United States)

    Orenes-Piñero, Esteban; García-Carmona, Francisco; Sánchez-Ferrer, Alvaro

    2013-08-15

    Phenol hydroxylase gene cloning from the thermophilic bacteria Geobacillus thermoglucosidasius was used to develop an effective method to convert tyrosol into the high-added-value compound hydroxytyrosol by hydroxylation. Phenol hydroxylase is a two-component enzyme encoded by pheA1 and pheA2 genes and strictly dependent on NADH and FAD. These two genes were subcloned together as a 2 kb fragment into Escherichia coli Rosetta cells, and the transformants were able to grow and effectively transform up to 5 mM of phenol and tyrosol using IPTG (isopropyl-β-D-thiogalactopyranoside) as inducer. In addition, when a new fragment with a 340 pb upstream pheA1 gene was subcloned, a similar biotransformation rate was attained without IPTG, confirming that this fragment encodes for a phenol hydroxylase promoter that can be recognised by E. coli. Both transformants brought about the total bioconversion of monophenols at a high concentration (5 mM), which represents an increase, both in concentration and in yield, compared with that previously described in the bibliography. The use of the transformant with its constitutive promoter was more interesting from a biotechnological point of view, since it is not necessary to use IPTG. It also gave rise to greater operational stability.

  8. Disequilibrium of BMP2 Levels in the Breast Stem Cell Niche Launches Epithelial Transformation by Overamplifying BMPR1B Cell Response

    Directory of Open Access Journals (Sweden)

    Marion Chapellier

    2015-02-01

    Full Text Available Understanding the mechanisms of cancer initiation will help to prevent and manage the disease. At present, the role of the breast microenvironment in transformation remains unknown. As BMP2 and BMP4 are important regulators of stem cells and their niches in many tissues, we investigated their function in early phases of breast cancer. BMP2 production by tumor microenvironment appeared to be specifically upregulated in luminal tumors. Chronic exposure of immature human mammary epithelial cells to high BMP2 levels initiated transformation toward a luminal tumor-like phenotype, mediated by the receptor BMPR1B. Under physiological conditions, BMP2 controlled the maintenance and differentiation of early luminal progenitors, while BMP4 acted on stem cells/myoepithelial progenitors. Our data also suggest that microenvironment-induced overexpression of BMP2 may result from carcinogenic exposure. We reveal a role for BMP2 and the breast microenvironment in the initiation of stem cell transformation, thus providing insight into the etiology of luminal breast cancer.

  9. Disequilibrium of BMP2 Levels in the Breast Stem Cell Niche Launches Epithelial Transformation by Overamplifying BMPR1B Cell Response

    Science.gov (United States)

    Chapellier, Marion; Bachelard-Cascales, Elodie; Schmidt, Xenia; Clément, Flora; Treilleux, Isabelle; Delay, Emmanuel; Jammot, Alexandre; Ménétrier-Caux, Christine; Pochon, Gaëtan; Besançon, Roger; Voeltzel, Thibault; Caron de Fromentel, Claude; Caux, Christophe; Blay, Jean-Yves; Iggo, Richard; Maguer-Satta, Véronique

    2015-01-01

    Summary Understanding the mechanisms of cancer initiation will help to prevent and manage the disease. At present, the role of the breast microenvironment in transformation remains unknown. As BMP2 and BMP4 are important regulators of stem cells and their niches in many tissues, we investigated their function in early phases of breast cancer. BMP2 production by tumor microenvironment appeared to be specifically upregulated in luminal tumors. Chronic exposure of immature human mammary epithelial cells to high BMP2 levels initiated transformation toward a luminal tumor-like phenotype, mediated by the receptor BMPR1B. Under physiological conditions, BMP2 controlled the maintenance and differentiation of early luminal progenitors, while BMP4 acted on stem cells/myoepithelial progenitors. Our data also suggest that microenvironment-induced overexpression of BMP2 may result from carcinogenic exposure. We reveal a role for BMP2 and the breast microenvironment in the initiation of stem cell transformation, thus providing insight into the etiology of luminal breast cancer. PMID:25601208

  10. Over-expression of human endosulfatase-1 exacerbates cadmium-induced injury to transformed human lung cells in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Huiying [Department of Molecular Biomedical Sciences, Center for Comparative Molecular Translational Research, College of Veterinary Medicine, NC State University, Raleigh, NC 27607 (United States); Department of Environmental and Molecular Toxicology, College of Agriculture and Life Sciences, NC State University, Raleigh, NC 27695 (United States); Newman, Donna R. [Department of Molecular Biomedical Sciences, Center for Comparative Molecular Translational Research, College of Veterinary Medicine, NC State University, Raleigh, NC 27607 (United States); Bonner, James C. [Department of Environmental and Molecular Toxicology, College of Agriculture and Life Sciences, NC State University, Raleigh, NC 27695 (United States); Sannes, Philip L., E-mail: philip_sannes@ncsu.edu [Department of Molecular Biomedical Sciences, Center for Comparative Molecular Translational Research, College of Veterinary Medicine, NC State University, Raleigh, NC 27607 (United States)

    2012-11-15

    Environmental exposure to cadmium is known to cause damage to alveolar epithelial cells of the lung, impair their capacity to repair, and result in permanent structural alterations. Cell surface heparan sulfate proteoglycans (HSPGs) can modulate cell responses to injury through their interactions with soluble effector molecules. These interactions are often sulfate specific, and the removal of sulfate groups from HS side chains could be expected to influence cellular injury, such as that caused by exposure to cadmium. The goal of this study was to define the role 6-O-sulfate plays in cellular responses to cadmium exposure in two pulmonary epithelial cancer cell lines (H292 and A549) and in normal human primary alveolar type II (hAT2) cells. Sulfate levels were modified by transduced transient over-expression of 6-O-endosulfatase (HSulf-1), a membrane-bound enzyme which specifically removes 6-O-sulfate groups from HSPG side chains. Results showed that cadmium decreased cell viability and activated apoptosis pathways at low concentrations in hAT2 cells but not in the cancer cells. HSulf-1 over-expression, on the contrary, decreased cell viability and activated apoptosis pathways in H292 and A549 cells but not in hAT2 cells. When combined with cadmium, HSulf-1 over-expression further decreased cell viability and exacerbated the activation of apoptosis pathways in the transformed cells but did not add to the toxicity in hAT2 cells. The finding that HSulf-1 sensitizes these cancer cells and intensifies the injury induced by cadmium suggests that 6-O-sulfate groups on HSPGs may play important roles in protection against certain environmental toxicants, such as heavy metals. -- Highlights: ► Primary human lung alveolar type 2 (hAT2) cells and H292 and A549 cells were used. ► Cadmium induced apoptosis in hAT2 cells but not in H292 or A549 cells. ► HSulf-1exacerbates apoptosis induced by cadmium in H292 and A549 but not hAT2 cells.

  11. Epithelial–mesenchymal transition during oncogenic transformation induced by hexavalent chromium involves reactive oxygen species-dependent mechanism in lung epithelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Song-Ze, E-mail: dingsongze@hotmail.com [Department of Internal Medicine, Henan Provincial People’s Hospital, Zhengzhou University, Wei-Wu Road, Zhengzhou, Henan 450000 (China); Graduate Center for Toxicology, College of Medicine, University of Kentucky, Lexington, KY 40536 (United States); Yang, Yu-Xiu; Li, Xiu-Ling [Department of Internal Medicine, Henan Provincial People’s Hospital, Zhengzhou University, Wei-Wu Road, Zhengzhou, Henan 450000 (China); Michelli-Rivera, Audrey [Graduate Center for Toxicology, College of Medicine, University of Kentucky, Lexington, KY 40536 (United States); Han, Shuang-Yin [Department of Internal Medicine, Henan Provincial People’s Hospital, Zhengzhou University, Wei-Wu Road, Zhengzhou, Henan 450000 (China); Wang, Lei; Pratheeshkumar, Poyil; Wang, Xin; Lu, Jian; Yin, Yuan-Qin; Budhraja, Amit; Hitron, Andrew J. [Graduate Center for Toxicology, College of Medicine, University of Kentucky, Lexington, KY 40536 (United States)

    2013-05-15

    Hexavalent chromium [Cr(VI)] is an important human carcinogen associated with pulmonary diseases and lung cancer. Exposure to Cr(VI) induces DNA damage, cell morphological change and malignant transformation in human lung epithelial cells. Despite extensive studies, the molecular mechanisms remain elusive, it is also not known if Cr(VI)-induced transformation might accompany with invasive properties to facilitate metastasis. We aimed to study Cr(VI)-induced epithelial–mesenchymal transition (EMT) and invasion during oncogenic transformation in lung epithelial cells. The results showed that Cr(VI) at low doses represses E-cadherin mRNA and protein expression, enhances mesenchymal marker vimentin expression and transforms the epithelial cell into fibroblastoid morphology. Cr(VI) also increases cell invasion and promotes colony formation. Further studies indicated that Cr(VI) uses multiple mechanisms to repress E-cadherin expression, including activation of E-cadherin repressors such as Slug, ZEB1, KLF8 and enhancement the binding of HDAC1 in E-cadherin gene promoter, but DNA methylation is not responsible for the loss of E-cadherin. Catalase reduces Cr(VI)-induced E-cadherin and vimentin protein expression, attenuates cell invasion in matrigel and colony formation on soft agar. These results demonstrate that exposure to a common human carcinogen, Cr(VI), induces EMT and invasion during oncogenic transformation in lung epithelial cells and implicate in cancer metastasis and prevention. - Graphical abstract: Epithelial–mesenchymal transition during oncogenic transformation induced by hexavalent chromium involves reactive oxygen species-dependent mechanisms in lung epithelial cells. - Highlights: • We study if Cr(VI) might induce EMT and invasion in epithelial cells. • Cr(VI) induces EMT by altering E-cadherin and vimentin expression. • It also increases cell invasion and promotes oncogenic transformation. • Catalase reduces Cr(VI)-induced EMT, invasion and

  12. Abnormal expression of c-Myc in human bronchial epithelial cells malignantly transformed by anti-BPDE

    Institute of Scientific and Technical Information of China (English)

    Juan FU; Yiguo JIANG; Xuemin CHEN

    2008-01-01

    Anti-benzo[a]pyrene-7,8-diol-9,10-epoxide (anti-BPDE) is a metabolite of benzo[a]pyrene (B[a] P) and acts as a potent mutagen in mammalian systems. However, molecular mechanisms related to anti-BPDE-induced carcinogenesis are poorly understood. Here, we investigated the expression of proto-oncogene c-myc in human bronchial epithelial cells (16H BE-T) transformed by exposure to anti-BPDE. The levels ofmRNA and pro-tein of c-M yc were examined in the 16HBE-T and vehicle-treated control cells (16HBE-N) by using different meth-ods respectively, including reverse transcriptase-polymer-ase chain reaction (RT-PCR), quantitative real-time PCR (Q-PCR), western blot and immunocytochemical meth-ods. The level of c-myc mRNA appeared to be signifi-cantly increased in 16HBE-T, as compared with those of the 16H BE-N. Likewise, the expression of c-Myc protein was significantly enhanced as compared with those of the control cells. Moreover, the localization of c-Myc protein shows mainly nuclear staining in 16HBE-T. In conclu-sion, the abnormal expression of c-Myc was present in anti-BPDE malignantly transformed 16HBE cells, which may be involved in the carcinogenesis molecular mech-anism of anti-BPDE.

  13. Slit-Robo signaling induces malignant transformation through Hakai-mediated E-cadherin degradation during colorectal epithelial cell carcinogenesis

    Institute of Scientific and Technical Information of China (English)

    Wei-Jie Zhou; Yan-Qing Ding; Jian-Guo Geng; Zhen H Geng; Shan Chi; Wenli Zhang; Xiao-Feng Niu; Shu-Jue Lan; Li Ma; Xuesong Yang; Li-Jing Wang

    2011-01-01

    The Slit family of guidance cues binds to Roundabout (Robo) receptors and modulates cell migration. We report here that ectopic expression of Slit2 and Robol or recombinant Slit2 treatment of Robol-expressing colorectal epithelial carcinoma cells recruited an ubiquitin ligase Hakai for E-cadherin (E-cad) ubiquitination and lysosomal degradation, epithelial-mesenchymal transition (EMT), and tumor growth and liver metastasis, which were rescued by knockdown of Hakai. In contrast, knockdown of endogenous Robol or specific blockade of Slit2 binding to Robol prevented E-cad degradation and reversed EMT, resulting in diminished tumor growth and liver metastasis.Ectopic expression of Robol also triggered a malignant transformation in Siit2-positive human embryonic kidney 293 cells. Importantly, the expression of Slit2 and Robol was significantly associated with an increased metastatic risk and poorer overall survival in colorectal carcinoma patients. We conclude that engagement of Robol by Slit2 induces malignant transformation through Hakai-mediated E-cad ubiquitination and lysosomal degradation during colorectal epithelial cell carcinogenesis.

  14. Establishment of Suspension Cell Culture from Agrobacterium-transformed Hairy Root Cells of Psammosilene tunicoides, an Endangered and Rare Medicinal Plant of China

    Directory of Open Access Journals (Sweden)

    Zhang Zong-Shen

    2015-08-01

    Full Text Available Psammosilene tunicoides is an important medicinal plant endemic in China. Its annual yield is severely limited due to slow growth, poor seed germination and excessive collection. To satisfy the growing market demands, it’s necessary to seek alternatives to field cultivation and wild resources of this endangered plant. Using Agrobacterium -transformed hairy roots as initial explants, here, we reported the development of a suspension cell culture system for P. tunicoides. Results showed the Agrobacterium -transformed hairy roots-derived suspension cells are fast in growth and strong in capacity for accumulation of bioactive metabolites. We established that 1/2MS was a suitable medium for culturing the hairy root-derived suspension cells and the optimal combination of phytohormones is 1.5 mg/L 2, 4-D+0.5 mg/L 6-BA+0.25 mg/L NAA+0.1 mg/L KT. Under this condition, the maximal biomass was achieved at the 20th day of culture with an average growth rate of 0.72 g/L/d; and the intracellular saponine content reached 0.92%, comparable to that of mother hairy roots. Compared with the normal P. tunicoides suspension cells, the hairy roots-derived suspension cells exhibited features of fast growth, short culture period and high concentration of saponines, suggesting that the large scale culture of hairy root-derived cells could be a feasible alternative to the wild resources of P. tunicoides.

  15. Apigenin suppresses migration and invasion of transformed cells through down-regulation of C-X-C chemokine receptor 4 expression

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Lei; Kuang, Lisha; Hitron, John Andrew; Son, Young-Ok; Wang, Xin; Budhraja, Amit [Graduate Center for Toxicology, College of Medicine, University of Kentucky, Lexington, KY 40536 (United States); Lee, Jeong-Chae [Graduate Center for Toxicology, College of Medicine, University of Kentucky, Lexington, KY 40536 (United States); Institute of Oral Biosciences and BK21 Program, Research Center of Bioactive Materials, Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Pratheeshkumar, Poyil [Graduate Center for Toxicology, College of Medicine, University of Kentucky, Lexington, KY 40536 (United States); Chen, Gang [Department of Internal Medicine, University of Kentucky College of Medicine, Lexington, KY 40536 (United States); Zhang, Zhuo [Graduate Center for Toxicology, College of Medicine, University of Kentucky, Lexington, KY 40536 (United States); Luo, Jia [Department of Internal Medicine, University of Kentucky College of Medicine, Lexington, KY 40536 (United States); Shi, Xianglin, E-mail: xshi5@email.uky.edu [Graduate Center for Toxicology, College of Medicine, University of Kentucky, Lexington, KY 40536 (United States)

    2013-10-01

    Environmental exposure to arsenic is known to cause various cancers. There are some potential relationships between cell malignant transformation and C-X-C chemokine receptor type 4 (CXCR4) expressions. Metastasis, one of the major characteristics of malignantly transformed cells, contributes to the high mortality of cells. CXCR4 and its natural chemokine ligand C-X-C motif ligand 12 (CXCL12) play a critical role in metastasis. Therefore, identification of nutritional factors which are able to inhibit CXCR4 is important for protection from environmental arsenic-induced carcinogenesis and for abolishing metastasis of malignantly transformed cells. The present study demonstrates that apigenin (4′,5,7-trihydroxyflavone), a natural dietary flavonoid, suppressed CXCR4 expression in arsenic-transformed Beas-2B cells (B-AsT) and several other types of transformed/cancer cells in a dose- and time-dependent manner. Neither proteasome nor lysosome inhibitor had any effect in reducing the apigenin-induced down-regulation of CXCR4, indicating that apigenin-induced down-regulation of CXCR4 is not due to proteolytic degradation. The down-regulation of CXCR4 is mainly due to the inhibition of nuclear factor κB (NF-κB) transcriptional activity. Apigenin also abolished migration and invasion of transformed cells induced by CXCL12. In a xenograft mouse model, apigenin down-regulated CXCR4 expression and suppressed tumor growth. Taken together, our results show that apigenin is a novel inhibitor of CXCR4 expression. This dietary flavonoid has the potential to suppress migration and invasion of transformed cells and prevent environmental arsenic-induced carcinogenesis. - Highlights: • Apigenin has a potential in preventing environmental arsenic induced carcinogenesis. • Apigenin suppresses CXCR4 in malignant transformed cells in vitro and in vivo. • The down-regulation of CXCR4 is mainly due to inhibition of NF-κB activity.

  16. Malignant transformation of mature T cells after gammaretrovirus mediated transfer of nucleophosmin-anaplastic lymphoma kinase oncogene

    Directory of Open Access Journals (Sweden)

    Ashok Kumar

    2015-01-01

    Full Text Available Background: Gene therapy has been in use to cure hereditary and acquired diseases by incorporating the desired gene into the cells with the help of gammaretroviral vectors. Despite the success of this therapy in X-linked severe combined immunodeficiency syndrome, few patients developed leukemia as a major adverse event due to retroviral insertional mutagenesis within stem cells. In experimental animals also, retroviral-mediated gene transfer technique resulted in the development of leukemia. On the other hand, evidence suggests that mature T cells (TC are relatively resistant to transformation even after retroviral-mediated transfer of potent oncogenes Tcl1, ΔTrkA and LMO2 with no reported side effects yet. Aims: To further address the safety issue for TC use in gene therapy, this study investigated susceptibility of mature polyclonal TC to malignant transformation by the retroviral-mediated transfer of nucleophosmin-anaplastic lymphoma kinase (NPM-ALK oncogene. Materials and Methods: Wild-type mature TC, isolated from C57BL/6 donor mice (genetic background Ly5.1 were transduced with gamma-retroviral vectors encoding the potent TC oncogene NPM-ALK or the control vector enhanced green fluorescent protein eGFP. The cells were then transplanted into RAG-1 deficient recipient mice (genetic background Ly5.2. Results: Two out of five mice from NPM-ALK oncogene group developed leukemia/lymphoma after latency periods (153 and 250 days, respectively. None of the mice from the control group developed any malignancy throughout the observational period. Conclusion: Mature polyclonal TC are relatively susceptible to malignant transformation after gamma-retroviral mediated transfer of NPM-ALK oncogene; hence safety of TC use in gene therapy should be further investigated to avoid the possible side-effect of development of leukemia/lymphoma.

  17. Characterisation of 20S Proteasome in Tritrichomonas foetus and Its Role during the Cell Cycle and Transformation into Endoflagellar Form.

    Directory of Open Access Journals (Sweden)

    Antonio Pereira-Neves

    Full Text Available Proteasomes are intracellular complexes that control selective protein degradation in organisms ranging from Archaea to higher eukaryotes. These structures have multiple proteolytic activities that are required for cell differentiation, replication and maintaining cellular homeostasis. Here, we document the presence of the 20S proteasome in the protist parasite Tritrichomonas foetus. Complementary techniques, such as a combination of whole genome sequencing technologies, bioinformatics algorithms, cell fractionation and biochemistry and microscopy approaches were used to characterise the 20S proteasome of T. foetus. The 14 homologues of the typical eukaryotic proteasome subunits were identified in the T. foetus genome. Alignment analyses showed that the main regulatory and catalytic domains of the proteasome were conserved in the predicted amino acid sequences from T. foetus-proteasome subunits. Immunofluorescence assays using an anti-proteasome antibody revealed a labelling distributed throughout the cytosol as punctate cytoplasmic structures and in the perinuclear region. Electron microscopy of a T. foetus-proteasome-enriched fraction confirmed the presence of particles that resembled the typical eukaryotic 20S proteasome. Fluorogenic assays using specific peptidyl substrates detected presence of the three typical peptidase activities of eukaryotic proteasomes in T. foetus. As expected, these peptidase activities were inhibited by lactacystin, a well-known specific proteasome inhibitor, and were not affected by inhibitors of serine or cysteine proteases. During the transformation of T. foetus to endoflagellar form (EFF, also known as pseudocyst, we observed correlations between the EFF formation rates, increases in the proteasome activities and reduced levels of ubiquitin-protein conjugates. The growth, cell cycle and EFF transformation of T. foetus were inhibited after treatment with lactacystin in a dose-dependent manner. Lactacystin

  18. Role of transforming growth factor beta in rat bladder smooth muscle cell proliferation

    NARCIS (Netherlands)

    Barendrecht, Maurits M.; Mulders, Arthur C. M.; van der Poel, Henk; van den Hoff, Maurice J. B.; Schmidt, Martina; Michel, Martin C.

    2007-01-01

    Conditions associated with hypertrophy of the urinary bladder have repeatedly been associated with an increased urinary excretion of transforming growth factor ( TGF)beta in both rats and patients. Because TGF beta can have both growth- promoting and - inhibiting effects, we have studied its effects

  19. Primary Breast Mucosa-Associated Lymphoid Tissue (MALT Lymphoma Transformation to Diffuse Large B-cell Lymphoma: A Case Report

    Directory of Open Access Journals (Sweden)

    Şerife Hülya Arslan

    2012-09-01

    Full Text Available Primary non-Hodgkin’s lymphoma (NHL of the breast constitutes 0.04%-0.53% of all malignancies and 2.2% of extra nodal lymphomas. In total, 7%-8% of all B-cell lymphomas are the mucosa-associated lymphoid tissue (MALT type, of which up to 50% of primary gastric MALT lymphoma. Herein we present a patient with breast MALT lymphoma that transformed to diffuse large B-cell lymphoma (DLBCL. A 69-year-old female presented with a mass on her left breast. Physical examination showed a 3 × 3-cm mass located 1 cm from the areola on the upper lateral quadrant of the breast at the 1 o’clock position, which was fixed and firm. Excisional biopsy was performed and pathologic examination of the specimen showed MALT lymphoma transformation to DLBCL. The patient was staged as II-EA. The rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone (R-CHOP protocol was scheduled as treatment. Following 6 courses of R-CHOP, 2 additional courses of rituximab were administered. Positron emission tomography (PET-CT was done at the end of the treatment. PET showed that the patient was in complete remission. At the time this report was written, the patient was being followed-up at the outpatient clinic on a regular basis. Lymphoma of the breast is a rarity among malignant tumors of the breast. The most common type of lymphoma is DLBCL. Breast MALT lymphoma is extremely rare. Primary MALT lymphoma of the breast can transform from low grade to high grade and recurrence is possible; therefore, such patients should be monitored carefully for transformation.

  20. c-Myc Transforms Human Mammary Epithelial Cells through Repression of the Wnt Inhibitors DKK1 and SFRP1▿ †

    Science.gov (United States)

    Cowling, Victoria H.; D'Cruz, Celina M.; Chodosh, Lewis A.; Cole, Michael D.

    2007-01-01

    c-myc is frequently amplified in breast cancer; however, the mechanism of myc-induced mammary epithelial cell transformation has not been defined. We show that c-Myc induces a profound morphological transformation in human mammary epithelial cells and anchorage-independent growth. c-Myc suppresses the Wnt inhibitors DKK1 and SFRP1, and derepression of DKK1 or SFRP1 reduces Myc-dependent transforming activity. Myc-dependent repression of DKK1 and SFRP1 is accompanied by Wnt target gene activation and endogenous T-cell factor activity. Myc-induced mouse mammary tumors have repressed SFRP1 and increased expression of Wnt target genes. DKK1 and SFRP1 inhibit the transformed phenotype of breast cancer cell lines, and DKK1 inhibits tumor formation. We propose a positive feedback loop for activation of the c-myc and Wnt pathways in breast cancer. PMID:17485441

  1. TRANSFORMING GROWTH FACTOR-BETA MEDIATED SUPPRESSION OF ANTI-TUMOR T CELLS REQUIRES FOXP1 TRANSCRIPTION FACTOR EXPRESSION

    Science.gov (United States)

    Stephen, Tom L.; Rutkowski, Melanie R.; Allegrezza, Michael J.; Perales-Puchalt, Alfredo; Tesone, Amelia J.; Svoronos, Nikolaos; Nguyen, Jenny M.; Sarmin, Fahmida; Borowsky, Mark E.; Tchou, Julia; Conejo-Garcia, Jose R.

    2014-01-01

    SUMMARY Tumor-reactive T cells become unresponsive in advanced tumors. Here we have characterized a common mechanism of T cell unresponsiveness in cancer driven by the up-regulation of the transcription factor Forkhead box protein P1 (Foxp1), which prevents CD8+ T cells from proliferating and up-regulating Granzyme-B and interferon-γ (IFN-γ) in response to tumor antigens. Accordingly, Foxp1-deficient lymphocytes induced rejection of incurable tumors, and promoted protection against tumor re-challenge. Mechanistically, Foxp1 interacted with the transcription factors Smad2 and Smad3 in pre-activated CD8+ T cells in response to microenvironmental transforming growth factor-β (TGF-β), and was essential for its suppressive activity. Therefore, Smad2 and Smad3-mediated c-Myc repression requires Foxp1 expression in T cells. Furthermore, Foxp1 directly mediated TGF-β-induced c-Jun transcriptional repression, which abrogated T cell activity. Our results unveil a fundamental mechanism of T cell unresponsiveness different from anergy or exhaustion, driven by TGF-β signaling on tumor-associated lymphocytes undergoing Foxp1-dependent transcriptional regulation. PMID:25238097

  2. Transforming Growth Factor-Beta and Matrix Metalloproteinases: Functional Interactions in Tumor Stroma-Infiltrating Myeloid Cells

    Directory of Open Access Journals (Sweden)

    Jelena Krstic

    2014-01-01

    Full Text Available Transforming growth factor-beta (TGF-β is a pleiotropic factor with several different roles in health and disease. In tumorigenesis, it may act as a protumorigenic factor and have a profound impact on the regulation of the immune system response. Matrix metalloproteinases (MMPs are a family that comprises more than 25 members, which have recently been proposed as important regulators acting in tumor stroma by regulating the response of noncellular and cellular microenvironment. Tumor stroma consists of several types of resident cells and infiltrating cells derived from bone marrow, which together play crucial roles in the promotion of tumor growth and metastasis. In cancer cells, TGF-β regulates MMPs expression, while MMPs, produced by either cancer cells or residents’ stroma cells, activate latent TGF-β in the extracellular matrix, together facilitating the enhancement of tumor progression. In this review we will focus on the compartment of myeloid stroma cells, such as tumor-associated macrophages, neutrophils, and dendritic and mast cells, which are potently regulated by TGF-β and produce large amounts of MMPs. Their interplay and mutual implications in the generation of pro-tumorigenic cancer microenvironment will be analyzed.

  3. A Novel Therapy for Melanoma Developed in Mice: Transformation of Melanoma into Dendritic Cells with Listeria monocytogenes

    Science.gov (United States)

    Bronchalo-Vicente, Lucia; Rodriguez-Del Rio, Estela; Freire, Javier; Calderon-Gonzalez, Ricardo; Frande-Cabanes, Elisabet; Gomez-Roman, Jose Javier; Fernández-Llaca, Hector; Yañez-Diaz, Sonsoles; Alvarez-Dominguez, Carmen

    2015-01-01

    Listeria monocytogenes is a gram-positive bacteria and human pathogen widely used in cancer immunotherapy because of its capacity to induce a specific cytotoxic T cell response in tumours. This bacterial pathogen strongly induces innate and specific immunity with the potential to overcome tumour induced tolerance and weak immunogenicity. Here, we propose a Listeria based vaccination for melanoma based in its tropism for these tumour cells and its ability to transform in vitro and in vivo melanoma cells into matured and activated dendritic cells with competent microbicidal and antigen processing abilities. This Listeria based vaccination using low doses of the pathogen caused melanoma regression by apoptosis as well as bacterial clearance. Vaccination efficacy is LLO dependent and implies the reduction of LLO-specific CD4+ T cell responses, strong stimulation of innate pro-inflammatory immune cells and a prevalence of LLO-specific CD8+ T cells involved in tumour regression and Listeria elimination. These results support the use of low doses of pathogenic Listeria as safe melanoma therapeutic vaccines that do not require antibiotics for bacterial removal. PMID:25760947

  4. p53-independent upregulation of p21WAF1 in NIH 3T3 cells malignantly transformed by mot-2

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    ot-2 protein is shown to interact with p53 and inhibit its transcriptional activation function.Mot-2 overexpressing stable clones of NIH 3T3 cells were malignantly transformed,however,they had a high level of expression of a p53 downstream gene,P21waf1.The present study was undertaken to elucidate possible molecular mechanism(s) of such upregulation.An increased level of P21waf1 expression was detected in stable transfectants although an exogenous reporter gene driven by P21waf1 promoter exhibited lower activity in these cells suggesting that some post-transcriptional mechanism contributes to upregulation.Western analyses of transient and stable clones revealed that upregulation of P21waf1 in stable NIH 3T3/mot-2 cells may be mediated by cyclin D1 and cdk-2.

  5. Insulin-like growth factor-binding protein-3 promotes transforming growth factor-β1-mediated epithelial-to-mesenchymal transition and motility in transformed human esophageal cells

    OpenAIRE

    Natsuizaka, Mitsuteru; Ohashi, Shinya; Wong, Gabrielle S; Ahmadi, Azal; Kalman, Ross A.; Budo, Daniela; Klein-Szanto, Andres J.; Herlyn, Meenhard; Diehl, J. Alan; Nakagawa, Hiroshi

    2010-01-01

    Insulin-like growth factor-binding protein (IGFBP)-3 is overexpressed frequently in esophageal squamous cell carcinoma. Yet, the role of IGFBP3 in esophageal tumor biology remains to be elucidated. We find that IGFBP3 facilitates transforming growth factor (TGF)-β1-mediated epithelial-to-mesenchymal transition (EMT) in transformed human esophageal epithelial cells, EPC2–hTERT–EGFR–p53R175H. In organotypic 3D culture, a form of human tissue engineering, laser-capture microdissection revealed c...

  6. NIH 3T3 cells stably transfected with the gene encoding phosphatidylcholine-hydrolyzing phospholipase C from Bacillus cereus acquire a transformed phenotype.

    OpenAIRE

    Johansen, T.; Bjørkøy, G; Overvatn, A; Diaz-Meco, M T; Traavik, T; Moscat, J

    1994-01-01

    In order to determine whether chronic elevation of intracellular diacylglycerol levels generated by hydrolysis of phosphatidylcholine (PC) by PC-hydrolyzing phospholipase C (PC-PLC) is oncogenic, we generated stable transfectants of NIH 3T3 cells expressing the gene encoding PC-PLC from Bacillus cereus. We found that constitutive expression of this gene (plc) led to transformation of NIH 3T3 cells as evidenced by anchorage-independent growth in soft agar, formation of transformed foci in tiss...

  7. Environmental particulate (PM2.5 augments stiffness-induced alveolar epithelial cell mechanoactivation of transforming growth factor beta.

    Directory of Open Access Journals (Sweden)

    Marilyn M Dysart

    Full Text Available Dysfunctional pulmonary homeostasis and repair, including diseases such as pulmonary fibrosis (PF, chronic obstructive pulmonary disease (COPD, and tumorigenesis have been increasing over the past decade, a fact that heavily implicates environmental influences. Several investigations have suggested that in response to increased transforming growth factor--beta (TGFβ signaling, the alveolar type II (ATII epithelial cell undergoes phenotypic changes that may contribute to the complex pathobiology of PF. We have previously demonstrated that increased tissue stiffness associated with PF is a potent extracellular matrix (ECM signal for epithelial cell activation of TGFβ. The work reported here explores the relationship between tissue stiffness and exposure to environmental stimuli in the activation of TGFβ. We hypothesized that exposure of ATII cells to fine particulate matter (PM2.5 will result in enhanced cell contractility, TGFβ activation, and subsequent changes to ATII cell phenotype. ATII cells were cultured on increasingly stiff substrates with or without addition of PM2.5. Exposure to PM2.5 resulted in increased activation of TGFβ, increased cell contractility, and elongation of ATII cells. Most notably, on 8 kPa substrates, a stiffness greater than normal but less than established fibrotic lung, addition of PM2.5 resulted in increased cortical cell stiffness, enhanced actin staining and cell elongation; a result not seen in the absence of PM2.5. Our work suggests that PM2.5 exposure additionally enhances the existing interaction between ECM stiffness and TGFβ that has been previously reported. Furthermore, we show that this additional enhancement is likely a consequence of intracellular reactive oxygen species (ROS leading to increased TGFβ signaling events. These results highlight the importance of both the micromechanical and biochemical environment in lung disease initiation and suggest that individuals in early stages of lung

  8. Transformation of human mesenchymal stem cells in radiation carcinogenesis: long-term effect of ionizing radiation

    DEFF Research Database (Denmark)

    Christensen, Rikke; Alsner, Jan; Sørensen, Flemming Brandt;

    2008-01-01

    Increasing evidence on cancer stem cells suggest that stem cells are susceptive to carcinogenesis and consequently can be the origin of many cancers. We have recently established a telomerase-transduced human mesenchymal stem cell line and subsequently irradiated this in order to achieve malignant...

  9. Immunoproliferative Small Intestinal Disease Associated with Overwhelming Polymicrobial Gastrointestinal Infection with Transformation to Diffuse Large B-cell Lymphoma.

    Science.gov (United States)

    Ewers, Evan C; Sheffler, Robert L; Wang, James; Ngauy, Viseth

    2016-05-01

    Immunoproliferative small intestinal disease (IPSID) is an extra-nodal B-cell lymphoma most commonly described in the Mediterranean, Africa, and Asia. It is associated with poverty and poor sanitation, and is rarely encountered in developed countries. A 26-year-old previously healthy, Marshallese male was transferred to our facility with a 6-month history of watery diarrhea, weakness, and cachexia refractory to multiple short courses of oral antibiotics. Stool cultures grew Campylobacter jejuni and Vibrio fluvialis. Endoscopic evaluation showed histologic evidence of Helicobacter pylori gastritis and gross evidence of whipworm infection found in the colon. Mesenteric lymph node biopsy cultures grew Escherichia coli. Histopathology and immunohistochemical stains of the small intestine were consistent with IPSID. He subsequently transformed to diffuse large B-cell lymphoma (DLBCL) with tonsillar involvement despite treatment with rituximab and an extended course of antibiotics. Systemic chemotherapy with six cycles of rituximab, cyclophosphamide, vincristine, doxorubicin, prednisone, and lenalidomide, resulted in remission of his diffuse B cell lymphoma. This case is illustrative of IPSID developing in a previously healthy individual due to overwhelming polymicrobial gastrointestinal infection by C. jejuni and other enteric pathogens with subsequent transformation to an aggressive DLBCL. IPSID should be considered in residents of developing countries presenting with refractory chronic diarrhea, weight loss, and mesenteric lymphadenopathy. PMID:26903604

  10. Paclitaxel-loaded ethosomes®: potential treatment of squamous cell carcinoma, a malignant transformation of actinic keratoses.

    Science.gov (United States)

    Paolino, Donatella; Celia, Christian; Trapasso, Elena; Cilurzo, Felisa; Fresta, Massimo

    2012-05-01

    Topical application of anticancer drugs for the treatment of malignancies represents a new challenge in dermatology, potentially being an alternative therapeutic approach for the efficacious treatment of non-melanoma skin cancer, that is, actinic keratoses, and malignant lesions of the skin caused by ultraviolet radiation. Anti-proliferative and antimitotic drugs, including many of the taxanes, are currently under investigation for the treatment of cutaneous malignant transformation of actinic keratoses, particularly the squamous cell carcinoma. Paclitaxel-loaded ethosomes® are proposed as topical drug delivery systems for the treatment of this pathology due to their suitable physicochemical characteristics and enhanced skin penetration ability for deep dermal delivery. Our in vitro data show that the skin application of paclitaxel-loaded ethosomes® improved the permeation of paclitaxel in a stratum corneum-epidermis membrane model and increased its anti-proliferative activity in a squamous cell carcinoma model as compared to the free drug. The results obtained encouraged the use of the paclitaxel-loaded ethosomes® as the formulation for the potential treatment of squamous cell carcinoma, a malignant transformation of actinic keratoses. PMID:22414731

  11. Paclitaxel-loaded ethosomes®: potential treatment of squamous cell carcinoma, a malignant transformation of actinic keratoses.

    Science.gov (United States)

    Paolino, Donatella; Celia, Christian; Trapasso, Elena; Cilurzo, Felisa; Fresta, Massimo

    2012-05-01

    Topical application of anticancer drugs for the treatment of malignancies represents a new challenge in dermatology, potentially being an alternative therapeutic approach for the efficacious treatment of non-melanoma skin cancer, that is, actinic keratoses, and malignant lesions of the skin caused by ultraviolet radiation. Anti-proliferative and antimitotic drugs, including many of the taxanes, are currently under investigation for the treatment of cutaneous malignant transformation of actinic keratoses, particularly the squamous cell carcinoma. Paclitaxel-loaded ethosomes® are proposed as topical drug delivery systems for the treatment of this pathology due to their suitable physicochemical characteristics and enhanced skin penetration ability for deep dermal delivery. Our in vitro data show that the skin application of paclitaxel-loaded ethosomes® improved the permeation of paclitaxel in a stratum corneum-epidermis membrane model and increased its anti-proliferative activity in a squamous cell carcinoma model as compared to the free drug. The results obtained encouraged the use of the paclitaxel-loaded ethosomes® as the formulation for the potential treatment of squamous cell carcinoma, a malignant transformation of actinic keratoses.

  12. Observation of radiation-specific damage in human cells exposed to depleted uranium: dicentric frequency and neoplastic transformation as endpoints

    International Nuclear Information System (INIS)

    Depleted uranium (DU) is a dense heavy metal used primarily in military applications. Published data from our laboratory have demonstrated that DU exposure in vitro to immortalised human osteoblast cells (HOS) is both neoplastically transforming and genotoxic. DU possesses both a radiological (alpha-particle) and chemical (metal) component. Since DU has a low specific activity in comparison to natural uranium, it is not considered to be a significant radiological hazard. The potential contribution of radiation to DU-induced biological effects is unknown and the involvement of radiation in DU-induced biological effects could have significant implication for current risk estimates for internalised DU exposure. Two approaches were used to address this question. The frequency of dicentrics was measured in HOS cells following DU exposure in vitro. Data demonstrated that DU exposure (50 μM, 24h) induced a significant elevation in dicentric frequency in vitro in contrast to incubation with the heavy metals, nickel and tungsten which did not increase dicentric frequency above background levels. Using the same concentration (50 μM) of three uranyl nitrate compounds that have different uranium isotopic concentrations and therefore, different specific activities, the effect on neoplastic transformation in vitro was examined. HOS cells were exposed to one of three-uranyl nitrate compounds (238U-uranyl nitrate, specific activity 0.33 μCi.g-1: DU-uranyl nitrate, specific activity 0.44 μCi.g-1: and 235U-uranyl nitrate, specific activity 2.2 μCi.g-1) delivered at a concentration of 50 μM for 24 h. Results showed, at equal uranium concentration, there was a specific activity dependent increase in neoplastic transformation frequency. Taken together these data suggest that radiation can play a role in DU-induced biological effects in vitro. (author)

  13. Differences in the epigenetic regulation of MT-3 gene expression between parental and Cd+2 or As+3 transformed human urothelial cells

    Directory of Open Access Journals (Sweden)

    Ajjimaporn Amornpan

    2011-02-01

    Full Text Available Abstract Background Studies have shown that metallothionein 3 (MT-3 is not expressed in normal urothelium or in the UROtsa cell line, but is expressed in urothelial cancer and in tumors generated from the UROtsa cells that have been transformed by cadmium (Cd+2 or arsenite (As+3.The present study had two major goals. One, to determine if epigenetic modifications control urothelial MT-3 gene expression and if regulation is altered by malignant transformation by Cd+2 or As+3. Two, to determine if MT-3 expression might translate clinically as a biomarker for malignant urothelial cells released into the urine. Results The histone deacetylase inhibitor MS-275 induced MT-3 mRNA expression in both parental UROtsa cells and their transformed counterparts. The demethylating agent, 5-Aza-2'-deoxycytidine (5-AZC had no effect on MT-3 mRNA expression. ChIP analysis showed that metal-responsive transformation factor-1 (MTF-1 binding to metal response elements (MRE elements of the MT-3 promoter was restricted in parental UROtsa cells, but MTF-1 binding to the MREs was unrestricted in the transformed cell lines. Histone modifications at acetyl H4, trimethyl H3K4, trimethyl H3K27, and trimethyl H3K9 were compared between the parental and transformed cell lines in the presence and absence of MS-275. The pattern of histone modifications suggested that the MT-3 promoter in the Cd+2 and As+3 transformed cells has gained bivalent chromatin structure, having elements of being "transcriptionally repressed" and "transcription ready", when compared to parental cells. An analysis of MT-3 staining in urinary cytologies showed that a subset of both active and non-active patients with urothelial cancer shed positive cells in their urine, but that control patients only rarely shed MT-3 positive cells. Conclusion The MT-3 gene is silenced in non-transformed urothelial cells by a mechanism involving histone modification of the MT-3 promoter. In contrast, transformation of the

  14. Cells transformed by PLC-gamma 1 overexpression are highly sensitive to clostridium difficile toxin A-induced apoptosis and mitotic inhibition.

    Science.gov (United States)

    Nam, Hyo Jung; Kang, Jin Ku; Chang, Jong Soo; Lee, Min Soo; Nam, Seung Taek; Jung, Hyun Woo; Kim, Sung-Kuk; Ha, Eun-Mi; Seok, Heon; Son, Seung Woo; Park, Young Joo; Kim, Ho

    2012-01-01

    Phospholipase C-γl (PLC-γl) expression is associated with cellular transformation. Notably, PLC-gamma is up-regulated in colorectal cancer tissue and breast carcinoma. Because exotoxins released by Clostridium botulinum have been shown to induce apoptosis and promote growth arrest in various cancer cell lines, we examined here the potential of Clostridium difficile toxin A to selectively induce apoptosis in cells transformed by PLC-γl overexpression. We found that PLC-γl-transformed cells, but not vectortransformed (control) cells, were highly sensitive to C. difficile toxin A-induced apoptosis and mitotic inhibition. Moreover, expression of the proapoptotic Bcl2 family member, Bim, and activation of caspase-3 were significantly up-regulated by toxin A in PLC-γl-transformed cells. Toxin A-induced cell rounding and paxillin dephosphorylation were also significantly higher in PLC-γl-transformed cells than in control cells. These findings suggest that C. difficile toxin A may have potential as an anticancer agent against colorectal cancers and breast carcinomas in which PLC-γl is highly up-regulated.

  15. Two-Dimensional Discrete Wavelet Transform on Large Images for Hybrid Computing Architectures: GPU and CELL

    OpenAIRE

    Alexander, Michael; D’Ambra, Pasqua; Belloum, Adam; Bosilca, George; Cannataro, Mario; Danelutto, Marco; Martino, Beniamino; Gerndt, Michael; Jeannot, Emmanuel; Namyst, Raymond; Roman, Jean; Scott, Stephen L.; Traff, Jesper Larsson; Vallée, Geoffroy; Weidendorfer, Josef

    2012-01-01

    The Discrete Wavelet Transform (DWT) has gained the momentum in signal processing and image compression over the last decade bringing the concept up to the level of new image coding standard JPEG2000. Thanks to many added values in DWT, in particular inherent multi-resolution nature, wavelet-coding schemes are suitable for various applications where scalability and tolerable degradation are rel- evant. Moreover, as we demonstrate in this paper, it can be used as a perfect benchmarking procedu...

  16. A rapid method to screen for cell-wall mutants using discriminant analysis of Fourier transform infrared spectra

    International Nuclear Information System (INIS)

    We have developed a rapid method to screen large numbers of mutant plants for a broad range of cell wall phenotypes using Fourier transform infrared (FTIR) microspectroscopy of leaves. We established and validated a model that can discriminate between the leaves of wild-type and a previously defined set of cell-wall mutants of Arabidopsis. Exploratory principal component analysis indicated that mutants deficient in different cell-wall sugars can be distinguished from each other. Discrimination of cell-wall mutants from wild-type was independent of variability in starch content or additional unrelated mutations that might be present in a heavily mutagenised population. We then developed an analysis of FTIR spectra of leaves obtained from over 1000 mutagenised flax plants, and selected 59 plants whose spectral variation from wild-type was significantly out of the range of a wild-type population, determined by Mahalanobis distance. Cell wall sugars from the leaves of selected putative mutants were assayed by gas chromatography-mass spectrometry and 42 showed significant differences in neutral sugar composition. The FTIR spectra indicated that six of the remaining 17 plants have altered ester or protein content. We conclude that linear discriminant analysis of FTIR spectra is a robust method to identify a broad range of structural and architectural alterations in cell walls, appearing as a consequence of developmental regulation, environmental adaptation or genetic modification. (author)

  17. Profiling of Concanavalin A-Binding Glycoproteins in Human Hepatic Stellate Cells Activated with Transforming Growth Factor-β1

    Directory of Open Access Journals (Sweden)

    Yannan Qin

    2014-11-01

    Full Text Available Glycoproteins play important roles in maintaining normal cell functions depending on their glycosylations. Our previous study indicated that the abundance of glycoproteins recognized by concanavalin A (ConA was increased in human hepatic stellate cells (HSCs following activation by transforming growth factor-β1 (TGF-β1; however, little is known about the ConA-binding glycoproteins (CBGs of HSCs. In this study, we employed a targeted glycoproteomics approach using lectin-magnetic particle conjugate-based liquid chromatography-tandem mass spectrometry to compare CBG profiles between LX-2 HSCs with and without activation by TGF-β1, with the aim of discovering novel CBGs and determining their possible roles in activated HSCs. A total of 54 and 77 proteins were identified in the quiescent and activated LX-2 cells, respectively. Of the proteins identified, 14.3% were glycoproteins and 73.3% were novel potential glycoproteins. Molecules involved in protein processing in the endoplasmic reticulum (e.g., calreticulin and calcium signaling (e.g., 1-phosphatidylinositol-4,5-bisphosphate phosphodiesterase β-2 [PLCB2] were specifically identified in activated LX-2 cells. Additionally, PLCB2 expression was upregulated in the cytoplasm of the activated LX-2 cells, as well as in the hepatocytes and sinusoidal cells of liver cirrhosis tissues. In conclusion, the results of this study may aid future investigations to find new molecular mechanisms involved in HSC activation and antifibrotic therapeutic targets.

  18. Measurement of ethanol formation in single living cells of Chlamydomonas reinhardtii using synchrotron Fourier Transform Infrared spectromicroscopy

    Science.gov (United States)

    Goff, Kira L.; Quaroni, Luca; Pedersen, Tor; Wilson, Kenneth E.

    2010-02-01

    We demonstrate the capability of Fourier-Transform Infra-Red (FITR) spectroscopy to detect metabolite formation by the unicellular algae Chlamydomonas reinhardtii in solution. We show that using a synchrotron source in the microscopy configuration provides a sufficient s/n ratio to detect small molecular species accumulating at a single cell, allowing an increased sensitivity relative to measurements of bulk cultures. The formation of small molecular species, including ethanol and at least one carbonyl containing compound, can be detected with a time resolution of the order of one minute.

  19. Measurement of ethanol formation in single living cells of Chlamydomonas reinhardtii using synchrotron Fourier Transform Infrared spectromicroscopy

    International Nuclear Information System (INIS)

    We demonstrate the capability of Fourier-Transform Infra-Red (FITR) spectroscopy to detect metabolite formation by the unicellular algae Chlamydomonas reinhardtii in solution. We show that using a synchrotron source in the microscopy configuration provides a sufficient s/n ratio to detect small molecular species accumulating at a single cell, allowing an increased sensitivity relative to measurements of bulk cultures. The formation of small molecular species, including ethanol and at least one carbonyl containing compound, can be detected with a time resolution of the order of one minute.

  20. Analysis of F-Canyon Effluents During the Dissolution Cycle with a Fourier Transform Infrared Spectrometer/Multipath Cell

    International Nuclear Information System (INIS)

    Air samples from F-Canyon effluents were collected at the F-Canyon stack and transported to a laboratory at the Savannah River Technology Center (SRTC) for analysis using a Fourier transform infrared spectrometer in conjunction with a multipath cell. Air samples were collected during the decladding and acid cuts of the dissolution of the irradiated aluminum-cladded slugs. The FTIR analyses of the air samples show the presence of NO2, NO, HNO2, N2O, SF6, and 85Kr during the dissolution cycle. The concentration time profiles of these effluents corresponded with expected release rates from the F-Canyon operations

  1. Epithelial-mesenchymal transition and cancer stem cells, mediated by a long non-coding RNA, HOTAIR, are involved in cell malignant transformation induced by cigarette smoke extract

    International Nuclear Information System (INIS)

    The incidence of lung diseases, including cancer, caused by cigarette smoke is increasing, but the molecular mechanisms of gene regulation induced by cigarette smoke remain unclear. This report describes a long noncoding RNA (lncRNA) that is induced by cigarette smoke extract (CSE) and experiments utilizing lncRNAs to integrate inflammation with the epithelial-mesenchymal transition (EMT) in human bronchial epithelial (HBE) cells. The present study shows that, induced by CSE, IL-6, a pro-inflammatory cytokine, leads to activation of STAT3, a transcription activator. A ChIP assay determined that the interaction of STAT3 with the promoter regions of HOX transcript antisense RNA (HOTAIR) increased levels of HOTAIR. Blocking of IL-6 with anti-IL-6 antibody, decreasing STAT3, and inhibiting STAT3 activation reduced HOTAIR expression. Moreover, for HBE cells cultured in the presence of HOTAIR siRNA for 24 h, the CSE-induced EMT, formation of cancer stem cells (CSCs), and malignant transformation were reversed. Thus, IL-6, acting on STAT3 signaling, which up-regulates HOTAIR in an autocrine manner, contributes to the EMT and to CSCs induced by CSE. These data define a link between inflammation and EMT, processes involved in the malignant transformation of cells caused by CSE. This link, mediated through lncRNAs, establishes a mechanism for CSE-induced lung carcinogenesis. - Highlights: • STAT3 directly regulates the levels of LncRNA HOTAIR. • LncRNA HOTAIR mediates the link between inflammation and EMT. • LncRNA HOTAIR is involved in the malignant transformation of cells caused by CSE

  2. Epithelial-mesenchymal transition and cancer stem cells, mediated by a long non-coding RNA, HOTAIR, are involved in cell malignant transformation induced by cigarette smoke extract

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yi; Luo, Fei; Xu, Yuan; Wang, Bairu; Zhao, Yue; Xu, Wenchao; Shi, Le; Lu, Xiaolin; Liu, Qizhan, E-mail: drqzliu@hotmail.com

    2015-01-01

    The incidence of lung diseases, including cancer, caused by cigarette smoke is increasing, but the molecular mechanisms of gene regulation induced by cigarette smoke remain unclear. This report describes a long noncoding RNA (lncRNA) that is induced by cigarette smoke extract (CSE) and experiments utilizing lncRNAs to integrate inflammation with the epithelial-mesenchymal transition (EMT) in human bronchial epithelial (HBE) cells. The present study shows that, induced by CSE, IL-6, a pro-inflammatory cytokine, leads to activation of STAT3, a transcription activator. A ChIP assay determined that the interaction of STAT3 with the promoter regions of HOX transcript antisense RNA (HOTAIR) increased levels of HOTAIR. Blocking of IL-6 with anti-IL-6 antibody, decreasing STAT3, and inhibiting STAT3 activation reduced HOTAIR expression. Moreover, for HBE cells cultured in the presence of HOTAIR siRNA for 24 h, the CSE-induced EMT, formation of cancer stem cells (CSCs), and malignant transformation were reversed. Thus, IL-6, acting on STAT3 signaling, which up-regulates HOTAIR in an autocrine manner, contributes to the EMT and to CSCs induced by CSE. These data define a link between inflammation and EMT, processes involved in the malignant transformation of cells caused by CSE. This link, mediated through lncRNAs, establishes a mechanism for CSE-induced lung carcinogenesis. - Highlights: • STAT3 directly regulates the levels of LncRNA HOTAIR. • LncRNA HOTAIR mediates the link between inflammation and EMT. • LncRNA HOTAIR is involved in the malignant transformation of cells caused by CSE.

  3. Transactivation of the TIEG1 confers growth inhibition of transforming growth factor-β-susceptible hepatocellular carcinoma cells

    Institute of Scientific and Technical Information of China (English)

    Lei Jiang; Yiu-Kay Lai; Jin-Fang Zhang; Chu-Yan Chan; Gang Lu; Marie CM Lin; Ming-Liang He; Ji-Cheng Li; Hsiang-Fu Kung

    2012-01-01

    AIM:To investigate the role of transforming growth factor (TGF)-β-inducible early gene 1 (TIEG1) in TGF-β-induced growth inhibition in hepatocellular carcinoma (HCC) cells.METHODS:Human hepatocyte and HCC cell lines with varied susceptibilities to TGF-β1 were tested by methylthiazoletetrazolium (MTT) assay.The expression changes of Smad2,Smad3,Smad4,Smad7,TIEG1 and TIEG2 gene following treatment with TGF-β1 in a TGF-β-sensitive hepatocyte cell line (MIHA),a TGF-β-sensitive hepatoma cell line (Hep3B) and two TGF-β-insensitive hepatoma cell lines (HepG2 and Bel7404)were examined.SiRNA targeting TIEG1 was transfected into Hep3B cells and the sensitivity of cells to TGF-β1 was examined.Overexpression of TIEG1 was induced by lentiviral-mediated transduction in TGF-β1-resistant hepatoma cell lines (Bel7404 and HepG2).MTT assay and 4',6-Diamidino-2-phenylindole staining were used to identify cell viability and apoptosis,respectively.The expression level of stathmin was measured by reverse transcriptase polymerase chain reaction and Western-blotting analysis,and stathmin promoter activity by TIEG1 was monitored by a luciferase reporter gene system.RESULTS:TIEG1 was significantly upregulated by TGF-β1 in the TGF-β1-sensitive HCC cell line,Hep3B,but not in the resistant cell lines.The suppression of TIEG1 by siRNAs decreased the sensitivity of Hep3B cells to TGF-β1,whereas the overexpression of TIEG1 mediated growth inhibition and apoptosis in TGF-β1-resistant HCC cell lines,which resembled those of TGF-β1-sensitive HCC cells treated with TGF-β1.Our data further suggested that stathmin was a direct target of TIEG1,as stathmin was significantly downregulated by TIEG1 overexpression,and stathmin promoter activity was inhibited by TIEG1 in a dose-dependent manner.CONCLUSION:Our data suggest that transactivation of TIEG1 conferred growth inhibition of TGF-β-susceptible human HCC cells.

  4. p16(INK4a) /Ki-67 co-expression specifically identifies transformed cells in the head and neck region.

    Science.gov (United States)

    Prigge, Elena-Sophie; Toth, Csaba; Dyckhoff, Gerhard; Wagner, Steffen; Müller, Franziska; Wittekindt, Claus; Freier, Kolja; Plinkert, Peter; Hoffmann, Jürgen; Vinokurova, Svetlana; Klussmann, Jens Peter; von Knebel Doeberitz, Magnus; Reuschenbach, Miriam

    2015-04-01

    p16(INK4a) immunohistochemical overexpression is an overall reliable surrogate marker of human papillomavirus (HPV)-associated head and neck squamous cell carcinomas (HNSCC). However, cases of ambiguous p16(INK4a) overexpression are regularly detected in the head and neck: p16(INK4a) expression can be observed in non-malignant tissue, such as tonsillar crypt epithelium and a proportion of branchial cleft cysts. Additionally, diverse patterns of p16(INK4) expression can complicate interpretation of "p16(INK4a) -positivity". These aspects impede the unrestricted application of p16(INK4a) as a diagnostic marker in the head and neck. We hypothesized that combined detection of p16(INK4a) and the proliferation marker Ki-67 could support clarification of ambiguous p16(INK4a) expression in the head and neck by specifically indicating p16(INK4a) -expressing cells with proliferative activity. p16(INK4a) /Ki-67 co-expression in a combined staining procedure was correlated to distinct p16(INK4a) expression patterns and HPV status (HPV DNA followed by E6*I oncogene mRNA detection) in 147 HNSCC and 50 non-malignant head and neck samples. p16(INK4a) /Ki-67 co-expression only occurred in transformed cells of the head and neck. Co-expression was never detected in non-transformed cells. Combined p16(INK4a) /Ki-67 expression was stringently associated with a diffuse p16(INK4a) expression pattern. All HPV oncogene-expressing HNSCC showed p16(INK4a) /Ki-67 co-expression. We demonstrate that p16(INK4a) /Ki-67 co-expression occurs exclusively in transformed cells of the head and neck. Our findings indicate a substantial impact of combined p16(INK4a) /Ki-67 expression in the assessment of ambiguous p16(INK4a) expression in the head and neck by specifically identifying p16(INK4a) -expressing cells with proliferative activity. This property will be of considerable significance for head and neck histo- and cytopathology.

  5. Transformation-associated changes in sphingolipid metabolism sensitize cells to lysosomal cell death induced by inhibitors of acid sphingomyelinase

    DEFF Research Database (Denmark)

    Petersen, Nikolaj H T; Olsen, Ole D; Groth-Pedersen, Line;

    2013-01-01

    Lysosomal membrane permeabilization and subsequent cell death may prove useful in cancer treatment, provided that cancer cell lysosomes can be specifically targeted. Here, we identify acid sphingomyelinase (ASM) inhibition as a selective means to destabilize cancer cell lysosomes. Lysosome-destab...

  6. Model Transformations? Transformation Models!

    NARCIS (Netherlands)

    Bézivin, J.; Büttner, F.; Gogolla, M.; Jouault, F.; Kurtev, I.; Lindow, A.

    2006-01-01

    Much of the current work on model transformations seems essentially operational and executable in nature. Executable descriptions are necessary from the point of view of implementation. But from a conceptual point of view, transformations can also be viewed as descriptive models by stating only the

  7. Activating the expression of human K-rasG12D stimulates oncogenic transformation in transgenic goat fetal fibroblast cells.

    Directory of Open Access Journals (Sweden)

    Jianhua Gong

    Full Text Available Humane use of preclinical large animal cancer models plays a critical role in understanding cancer biology and developing therapeutic treatments. Among the large animal candidates, goats have great potentials as sustainable sources for large animal cancer model development. Goats are easier to handle and cheaper to raise. The genome of the goats has been sequenced recently. It has been known that goats develop skin, adrenal cortex, breast and other types of cancers. Technically, goats are subject to somatic cell nuclear transfer more efficiently and exhibit better viability through the cloning process. Towards the development of a goat cancer model, we created a transgenic goat fetal fibroblast (GFF cell as the donor cell for SCNT. Human mutated K-ras (hK-rasG12D was chosen as the transgene, as it is present in 20% of cancers. Both hK-rasG12D and a herpes simplex viral thymidine kinase (HSV1-tk reporter genes, flanked by a pair of LoxP sites, were knocked in the GFF endogenous K-ras locus through homologous recombination. Following Cre-mediated activation (with a 95% activation efficiency, hK-rasG12D and HSV1-tk were expressed in the transgenic GFF cells, evidently through the presence of corresponding mRNAs, and confirmed by HSV1-tk protein function assay. The hK-rasG12D expressing GFF cells exhibited enhanced proliferation rates and an anchorage-independent growth behavior. They were able to initiate tumor growth in athymic nude mice. In conclusion, after activating hK-rasG12D gene expression, hK-rasG12D transgenic GFF cells were transformed into tumorgenesis cells. Transgenic goats via SCNT using the above-motioned cells as the donor cells have been established.

  8. Evaluation of transforming growth factor-β1 suppress Pokemon/epithelial-mesenchymal transition expression in human bladder cancer cells.

    Science.gov (United States)

    Li, Wei; Kidiyoor, Amritha; Hu, Yangyang; Guo, Changcheng; Liu, Min; Yao, Xudong; Zhang, Yuanyuan; Peng, Bo; Zheng, Junhua

    2015-02-01

    Transforming growth factor-β1 (TGF-β1) plays a dual role in apoptosis and in proapoptotic responses in the support of survival in a variety of cells. The aim of this study was to determine the function of TGF-β1 in bladder cancer cells and the relationship with POK erythroid myeloid ontogenic factor (Pokemon). TGF-β1 and its receptors mediate several tumorigenic cascades that regulate cell proliferation, migration, and survival of bladder cancer cells. Bladder cancer cells T24 were treated with different levels of TGF-β1. Levels of Pokemon, E-cadherin, Snail, MMP2, MMP9, Twist, VEGF, and β-catenin messenger RNA (mRNA) and protein were examined by real-time quantitative fluorescent PCR and Western blot analysis, respectively. The effects of TGF-β1 on epithelial-mesenchymal transition of T24 cells were evaluated with wound-healing assay, proliferation of T24 was evaluated with reference to growth curves with MTT assay, and cell invasive ability was investigated by Transwell assay. Data show that Pokemon was inhibited by TGF-β1 treatment; the gene and protein of E-cadherin and β-catenin expression level showed decreased markedly after TGF-β1 treatment (P Pokemon, β-catenin, and E-cadherin. The high expression of TGF-β1 leads to an increase in the phenotype and apical-base polarity of epithelial cells. These changes of cells may result in the recurrence and progression of bladder cancer at last. Related mechanism is worthy of further investigation. PMID:25722217

  9. The apoptotic effects of escin in the H-Ras transformed 5RP7 cell line.

    Science.gov (United States)

    Güney, G; Kutlu, H M; Işcan, A

    2013-06-01

    Extracts of Aesculus hippocastanum L. (horse chestnut) seed have been used in the treatment of chronic venous insufficiency, edema and hemorrhoids. Most of the beneficial effects of horse chestnut are attributed to its principal component β-escin or escin. We have evaluated the cytotoxic and apoptotic effects of escin in the H-Ras 5RP7 cell line by analyzing cell growth inhibition, apoptosis and caspase-3 dependent activity. We have also shown structural and ultrastructural changes in these cell using confocal and transmission electron microscopy. The results indicated that escin has significant inhibitory effects on cell growth and the percentage of apoptotic cells increased after treatment with escin, and the micrographs confirmed that escin damaged these cells and induced apoptosis. PMID:22911540

  10. Mature cystic teratoma with malignant transformation of teratomatous urothelial cells: Rare case presentation

    OpenAIRE

    Senjuti Dasgupta; Debdas Bose; Nirmal Kumar Bhattacharyya; Pranab Kumar Biswas

    2015-01-01

    The occurrence of malignancies in somatic elements of mature cystic teratoma of ovary is rare. The malignancies that may be encountered in dermoid cyst include squamous cell carcinoma, adenocarcinoma, adenosquamous carcinoma, melanoma, sarcoma, carcinoid, and germ cell neoplasms. The development of transitional cell carcinoma (TCC) in dermoid cyst is extremely rare with only four such cases having been reported in literature so far. Here we report the fifth case of such an occurrence in a 50-...

  11. ONCOGENIC TRANSFORMATION OF SYRIAN HAMSTER EMBRYO CELLS BY 5.3-MeVα PARTICLES AND A TUMOR PROMOTER PHORBOL ESTER

    Institute of Scientific and Technical Information of China (English)

    寿江; 龚诒芬; 吴德昌

    1996-01-01

    The primary Syrian hamster embryo(SHE) cells were used to study the oneogenic transformation by 235pu a particles or X-rays alone or in combination with a chemical promoter phorbol ester. Survival curves of SHE cells following exposure to a-partieles or X-rays were fitted to single-or multi-target models,respectively. Model parameters were:Do=0. 55 Gy,n= 1 for a particles;Do=l. 44 Gy,Dq 3. 0 Gy,n=7. 7 for X-rays. Incidence of a particles or X-rays induced cell transformation was dose-dependant, a partieles were more efficient in inducing cell transformation than that of X rays. The enhancement of SHE cell transformarion by phorbol 12-myristate 13-acetate(PMA) following exposure to a particles of 0. 25-1.00 Gy was observed.

  12. Metabolic responses of primary and transformed cells to intracellular Listeria monocytogenes.

    Directory of Open Access Journals (Sweden)

    Nadine Gillmaier

    Full Text Available The metabolic response of host cells, in particular of primary mammalian cells, to bacterial infections is poorly understood. Here, we compare the carbon metabolism of primary mouse macrophages and of established J774A.1 cells upon Listeria monocytogenes infection using (13C-labelled glucose or glutamine as carbon tracers. The (13C-profiles of protein-derived amino acids from labelled host cells and intracellular L. monocytogenes identified active metabolic pathways in the different cell types. In the primary cells, infection with live L. monocytogenes increased glycolytic activity and enhanced flux of pyruvate into the TCA cycle via pyruvate dehydrogenase and pyruvate carboxylase, while in J774A.1 cells the already high glycolytic and glutaminolytic activities hardly changed upon infection. The carbon metabolism of intracellular L. monocytogenes was similar in both host cells. Taken together, the data suggest that efficient listerial replication in the cytosol of the host cells mainly depends on the glycolytic activity of the hosts.

  13. Enhancement of beta-sitosterol transformation in Mycobacterium vaccae with increased cell wall permeability.

    Science.gov (United States)

    Korycka-Machała, M; Rumijowska-Galewicz, A; Lisowska, K; Ziolkowskit, A; Sedlacze, L

    2001-01-01

    Mycobacterium vaccae exposed to compounds which are known to disorganise the cell wall composition and architecture (protamine, glycine) showed increased specific activity in beta-sitosterol biotransformation to androstene derivatives, intennediates in the production of most medical steroids. GC/MS analysis of free lipid fatty acids revealed higher content of unsaturated compounds, mainly C16:1 and C18:1 in protamine- and glycine-treated cells than that in control cells, which seems to change the permeability features of the cell wall barrier, facilitating hydrophobic beta-sitosterol diffusion.

  14. Transforming growth factor-beta signaling network regulates plasticity and lineage commitment of lung cancer cells

    OpenAIRE

    Ischenko, I; Liu, J.; Petrenko, O; Hayman, M J

    2014-01-01

    Identification of target cells in lung tumorigenesis and characterization of the signals that control their behavior is an important step toward improving early cancer diagnosis and predicting tumor behavior. We identified a population of cells in the adult lung that bear the EpCAM+CD104+CD49f+CD44+CD24loSCA1+ phenotype and can be clonally expanded in culture, consistent with the properties of early progenitor cells. We show that these cells, rather than being restricted to one tumor type, ca...

  15. Identification of multiple SNT-binding sites on NPM-ALK oncoprotein and their involvement in cell transformation.

    Science.gov (United States)

    Chikamori, M; Fujimoto, J; Tokai-Nishizumi, N; Yamamoto, T

    2007-05-01

    The t(2;5) chromosomal translocation occurs in anaplastic large-cell lymphoma arising from activated T lymphocytes. This genomic rearrangement generates the nucleophosmin (NPM)-anaplastic lymphoma kinase (ALK) oncoprotein that is a chimeric protein consisting of parts of the nuclear protein NPM and ALK receptor protein-tyrosine kinase. We used yeast two-hybrid screening to identify an adaptor protein Suc1-associated neurotrophic factor-induced tyrosine-phosphorylated target (SNT)-2 as a new partner that interacted with the cytoplasmic domain of ALK. Immunoprecipitation assay revealed that SNT-1 and SNT-2 interacted with NPM-ALK and kinase-negative NPM-ALK mutant. Y156, Y567 and a 19-amino-acid sequence (aa 631-649) of NPM-ALK were essential for this interaction. The interaction through Y156 and Y567 was dependent on phosphorylation of these tyrosines, whereas the interaction through the 19-amino-acid sequence was independent of phosphorylation. NPM-ALK mutant protein mutated at these three binding sites showed significantly reduced transforming activity. This transformation-defective NPM-ALK mutant still interacted with signal transducing proteins such as phospholipase C-gamma and phosphatidylinositol 3-kinase, which were previously reported to be relevant to NPM-ALK-dependent tumorigenesis. These observations indicate that the three SNT-binding sites of NPM-ALK are important for its transforming activity. This raises a possibility that SNT family proteins play significant roles in cellular transformation triggered by NPM-ALK, which though remains to be verified.

  16. A method for the amplification of chemically induced transformation in C3H/10T1/2 clone 8 cells: its use as a potential screening assay.

    Science.gov (United States)

    Schechtman, L M; Kiss, E; McCarvill, J; Nims, R; Kouri, R E; Lubet, R A

    1987-09-01

    A method has been developed by which to amplify expression of phenotypic transformation of C3H/10T1/2 clone 8 mouse embryo cells not otherwise observed in the standard transformation assay. The expression of transformed foci was amplified by subcultivating chemically treated target cells after they had reached confluence and replating them at subconfluent cell densities. Conditions leading to the expression of the highest numbers of transformed foci include a) a cell seeding density for chemical treatment of 1 X 10(4) cells/dish, b) subculture 4 weeks after treatment, and c) replating cells at a density of 2 X 10(5) cells/-dish. Agents capable of inducing transformation in the standard assay (e.g., 4,4'-bis(dimethylamino)benzophenone, benzo[a]pyrene, 7,12-dimethylbenz[a]anthracene, and others) also yielded transformation in the replating assay. The more marginal transforming activities of chemicals such as ethyl methanesulfonate, 7-(bromomethyl)-12-methylbenz[a]anthracene, and N-methyl-N'-nitro-N-nitrosoguanidine were enhanced by the amplification procedure. Compounds that failed to elicit focal transformation in the standard assay (e.g., dibenz[a,h]anthracene, Tris(2,3-dibromopropyl) phosphate, lead acetate, benzidine, propyleneimine, N-hydroxy-2-fluorenylacetamide, and numerous other compounds of various chemical classes) induced significant levels of phenotypic transformation upon amplification. Noncarcinogens (e.g., phenanthrene, anthracene, 2-aminobiphenyl, cycloheximide, and others) failed to cause significant phenotypic transformation even when cells were replated. To further enhance the applicability of this new replating system, an exogenous source of metabolic activation was added: a 9,000 X g supernatant from Aroclor 1254-induced rat hepatic S-9. This activation system was found a) to be only minimally cytotoxic by itself and b) to be able to mediate NADPH-dependent, dose-dependent toxicity, and transformation by activating the procarcinogens

  17. Telomerase reverse transcriptase expression protects transformed human cells against DNA-damaging agents, and increases tolerance to chromosomal instability.

    Science.gov (United States)

    Fleisig, H B; Hukezalie, K R; Thompson, C A H; Au-Yeung, T T T; Ludlow, A T; Zhao, C R; Wong, J M Y

    2016-01-14

    Reactivation of telomerase reverse transcriptase (TERT) expression is found in more than 85% of human cancers. The remaining cancers rely on the alternative lengthening of telomeres (ALT), a recombination-based mechanism for telomere-length maintenance. Prevalence of TERT reactivation over the ALT mechanism was linked to secondary TERT function unrelated to telomere length maintenance. To characterize this non-canonical function, we created a panel of ALT cells with recombinant expression of TERT and TERT variants: TERT-positive ALT cells showed higher tolerance to genotoxic insults compared with their TERT-negative counterparts. We identified telomere synthesis-defective TERT variants that bestowed similar genotoxic stress tolerance, indicating that telomere synthesis activity is dispensable for this survival phenotype. TERT expression improved the kinetics of double-strand chromosome break repair and reduced DNA damage-related nuclear division abnormalities, a phenotype associated with ALT tumors. Despite this reduction in cytological abnormalities, surviving TERT-positive ALT cells were found to have gross chromosomal instabilities. We sorted TERT-positive cells with cytogenetic changes and followed their growth. We found that the chromosome-number changes persisted, and TERT-positive ALT cells surviving genotoxic events propagated through subsequent generations with new chromosome numbers. Our data confirm that telomerase expression protects against double-strand DNA (dsDNA)-damaging events, and show that this protective function is uncoupled from its role in telomere synthesis. TERT expression promotes oncogene-transformed cell growth by reducing the inhibitory effects of cell-intrinsic (telomere attrition) and cell-extrinsic (chemical- or metabolism-induced genotoxic stress) challenges. These data provide the impetus to develop new therapeutic interventions for telomerase-positive cancers through simultaneous targeting of multiple telomerase activities. PMID

  18. A study on the best irradiation dose of X-ray for Hep-2 cells by Fourier transform infrared spectroscopy

    Institute of Scientific and Technical Information of China (English)

    Renming Liu; Weiyue Tang; Guangshui Zhang; Fengqiu Zhang; Xinhui Yan

    2008-01-01

    Fourier transform infrared spectroscopy (FTIR) was employed to study the human epidermis larynx carcinoma cell lines (Hep-2) which were irradiated by different doses of X-ray.The results show that (1) the irradiation of X-ray damages the structure of the CH3 groups of the thymine in DNA,which restrains the reproduction of Hep-2 cells effectively,(2) the 8 Gy dose of X-ray irradiation changes the framework and the relative contents of some proteins,lipids and the nucleic acid molecules intercellular in the greatest degree,and (3) the 8 Gy dose of X-ray irradiation is the best irradiation dose for lowering the degree of the cancerization of Hep-2 cells according to the criteria for the degree of the cancerization reported recently.Meanwhile,the apoptosis of these cells were detected by using flow cytometry (FCM) primarily.It shows that the apoptotic ratio of the Hep-2 cells depends on the irradiation dose to some extent,but is not linearly.And the apoptotic ratio of the 12 Gy dose group is the maximum (20.36%),but the apoptotic ratios of the 2 to 8 Gy dose groups change little.

  19. Low-level laser therapy on MCF-7 cells: a micro-Fourier transform infrared spectroscopy study

    Science.gov (United States)

    Magrini, Taciana D.; dos Santos, Nathalia Villa; Milazzotto, Marcella Pecora; Cerchiaro, Giselle; da Silva Martinho, Herculano

    2012-10-01

    Low-level laser therapy (LLLT) is an emerging therapeutic approach for several clinical conditions. The clinical effects induced by LLLT presumably scale from photobiostimulation/photobioinhibition at the cellular level to the molecular level. The detailed mechanism underlying this effect remains unknown. This study quantifies some relevant aspects of LLLT related to molecular and cellular variations. Malignant breast cells (MCF-7) were exposed to spatially filtered light from a He-Ne laser (633 nm) with fluences of 5, 28.8, and 1000 mJ/cm2. The cell viability was evaluated by optical microscopy using the Trypan Blue viability test. The micro-Fourier transform infrared technique was employed to obtain the vibrational spectra of each experimental group (control and irradiated) and identify the relevant biochemical alterations that occurred due to the process. It was observed that the red light influenced the RNA, phosphate, and serine/threonine/tyrosine bands. We found that light can influence cell metabolism depending on the laser fluence. For 5 mJ/cm2, MCF-7 cells suffer bioinhibition with decreased metabolic rates. In contrast, for the 1 J/cm2 laser fluence, cells present biostimulation accompanied by a metabolic rate elevation. Surprisingly, at the intermediate fluence, 28.8 mJ/cm2, the metabolic rate is increased despite the absence of proliferative results. The data were interpreted within the retrograde signaling pathway mechanism activated with light irradiation.

  20. Ionizing Radiation Promotes Migration and Invasion of Cancer Cells Through Transforming Growth Factor-Beta-Mediated Epithelial-Mesenchymal Transition

    Energy Technology Data Exchange (ETDEWEB)

    Zhou Yongchun [Department of Radiation Oncology, Xijing Hospital Fourth Military Medical University, Xi' an (China); Department of Radiation Medicine, College of Preventive Medicine, Xijing Hospital Fourth Military Medical University, Xi' an (China); Liu Junye; Li Jing; Zhang Jie [Department of Radiation Medicine, College of Preventive Medicine, Xijing Hospital Fourth Military Medical University, Xi' an (China); Xu Yuqiao [Department of Pathology, Xijing Hospital Fourth Military Medical University, Xi' an (China); Zhang Huawei; Qiu Lianbo; Ding Guirong [Department of Radiation Medicine, College of Preventive Medicine, Xijing Hospital Fourth Military Medical University, Xi' an (China); Su Xiaoming [Department of Radiation Oncology, 306th Hospital of PLA, Beijing (China); Mei Shi [Department of Radiation Oncology, Xijing Hospital Fourth Military Medical University, Xi' an (China); Guo Guozhen, E-mail: guozhenguo@hotmail.com [Department of Radiation Medicine, College of Preventive Medicine, Xijing Hospital Fourth Military Medical University, Xi' an (China)

    2011-12-01

    Purpose: To examine whether ionizing radiation enhances the migratory and invasive abilities of cancer cells through transforming growth factor (TGF-{beta})-mediated epithelial-mesenchymal transition (EMT). Methods and Materials: Six cancer cell lines originating from different human organs were irradiated by {sup 60}Co {gamma}-ray at a total dose of 2 Gy, and the changes associated with EMT, including morphology, EMT markers, migration and invasion, were observed by microscope, Western blot, immunofluorescence, scratch assay, and transwell chamber assay, respectively. Then the protein levels of TGF-{beta} in these cancer cells were detected by enzyme-linked immunosorbent assay, and the role of TGF-{beta} signaling pathway in the effect of ionizing radiation on EMT was investigate by using the specific inhibitor SB431542. Results: After irradiation with {gamma}-ray at a total dose of 2 Gy, cancer cells presented the mesenchymal phenotype, and compared with the sham-irradiation group the expression of epithelial markers was decreased and of mesenchymal markers was increased, the migratory and invasive capabilities were strengthened, and the protein levels of TGF-{beta} were enhanced. Furthermore, events associated with EMT induced by IR in A549 could be reversed through inhibition of TGF-{beta} signaling. Conclusions: These results suggest that EMT mediated by TGF-{beta} plays a critical role in IR-induced enhancing of migratory and invasive capabilities in cancer cells.

  1. Endogenous ADP-ribosylation of elongation factor 2 in polyoma virus-transformed baby hamster kidney cells

    Energy Technology Data Exchange (ETDEWEB)

    Fendrick, J.L.; Iglewski, W.J. (Univ. of Rochester, NY (USA))

    1989-01-01

    Polyoma virus-transformed baby hamster kidney (pyBHK) cells were cultured in medium containing ({sup 32}P)orthophosphate and 105 (vol/vol) fetal bovine serum. A {sup 32}P-labeled protein with an apparent molecular mass of 97 kDa was immunoprecipitated from cell lysates with antiserum to ADP-ribosylated elongation factor 2 (EF-2). The {sup 32}P labeling of the protein was enhanced by culturing cells in medium containing 2% serum instead of 10% serum. The {sup 32}P label was completely removed from the protein by treatment with snake venom phosphodiesterase and the digestion product was identified as ({sup 32}P)AMP, indicating the protein was mono-ADP-ribosylated. HPLC analysis of tryptic peptides of the {sup 32}P-labeled 97-kDa protein and purified EF-2, which was ADP-ribosylated in vitro with diphtheria toxin fragment A and ({sup 32}P)NAD, demonstrated an identical labeled peptide in the two proteins. The data strongly suggest that EF-2 was endogenously ADP-ribosylated in pyBHK cells. Maximum incorporation of radioactivity in EF-2 occurred by 12 hr and remained constant over the subsequent 12 hr. It was estimated that 30-35% of the EF-2 was ADP-ribosylated in cells cultured in medium containing 2% serum. When {sup 32}P-labeled cultures were incubated in medium containing unlabeled phosphate, the {sup 32}P label was lost from the EF-2 within 30 min.

  2. Transforming growth factor-β1 increases lysyl oxidase expression by downregulating MIR29A in human granulosa lutein cells.

    Science.gov (United States)

    Fang, Ying; Chang, Hsun-Ming; Cheng, Jung-Chien; Klausen, Christian; Leung, Peter C K; Yang, Xiaokui

    2016-09-01

    Lysyl oxidase (LOX), a key enzyme in the formation and stabilization of the extracellular matrix, is expressed in granulosa cells and plays a critical role in the regulation of granulosa cell differentiation, oocyte maturation and ovulation. To date, the regulation of LOX expression in human granulosa cells remains largely unknown. In this study, using primary and immortalized human granulosa lutein cells, we demonstrated that transforming growth factor (TGF)-β1 (TGFB1) upregulated LOX expression and downregulated microRNA-29a (MIR29A) expression via a TGF-β type I receptor-mediated signaling pathway. Additionally, we showed that MIR29A downregulated the expression of LOX in both types of cells. Furthermore, the downregulation of MIR29A contributed to the TGFB1-induced increase in LOX expression because the inhibition of MIR29A with a MIR29A inhibitor not only reversed the MIR29A-induced downregulation of LOX but also enhanced the TGFB1-induced upregulation of LOX. Our findings suggest that TGFB1 and MIR29A may play essential roles in the regulation of extracellular matrix remodeling during the periovulatory phase. PMID:27335131

  3. Reciprocal regulation between O-GlcNAcylation and tribbles pseudokinase 2 (TRIB2) maintains transformative phenotypes in liver cancer cells.

    Science.gov (United States)

    Yao, Bingjie; Xu, Yanli; Wang, Jiayi; Qiao, Yongxia; Zhang, Yue; Zhang, Xiao; Chen, Yan; Wu, Qi; Zhao, Yinghui; Zhu, Guoqing; Sun, Fenyong; Li, Zhi; Yuan, Hong

    2016-11-01

    TRIB2 has been identified as an onco-protein, and O-GlcNAcylation of target proteins has been reported to stimulate transformative phenotypes in liver cancer cells. However, the relationships between TRIB2 and O-GlcNAcylation are still unknown. The aim of this study was to investigate whether and how O-GlcNAcylation and TRIB2 regulate each other. We found that stimulation of O-GlcNAcylation elevates TRIB2 by enhancing its protein stability. TRIB2 can be O-GlcNAcylated by the hexosamine biosynthesis pathway (HBP). Also, O-GlcNAcylation boosting of transformative phenotypes of liver cancer cells might occur in a TRIB2-dependent manner. Interestingly, TRIB2 stimulated the metabolism of HBP, demonstrating that TRIB2 has positive feedback on O-GlcNAcylation. Notably, TRIB2 was found to maintain the stability of guanylate cyclase 1 alpha 3 (GUCY1A3), a key component of HBP, by interacting GUCY1A3 and reducing its ubiquitination. Importantly, TRIB2-dependent regulation of metabolism, transformative phenotypes, and O-GlcNAcylation all rely on GUCY1A3. Mouse experiments demonstrate that O-GlcNAcylation of TRIB2 is much higher in the livers of diabetic mice compared to control mice, suggesting that O-GlcNAcylation of TRIB2 might be critical for diabetes-associated liver cancer. Collectively, we have uncovered a positive auto-regulatory feedback between O-GlcNAcylation and TRIB2, which might be regarded as a promising therapeutic target for liver cancer.

  4. DL-alpha-difluoromethylarginine inhibits intracellular Trypanosoma cruzi multiplication by affecting cell division but not trypomastigote-amastigote transformation.

    Science.gov (United States)

    Yakubu, M A; Basso, B; Kierszenbaum, F

    1992-06-01

    DL-alpha-difluoromethylarginine (DFMA), a specific, irreversible inhibitor of arginine decarboxylase (ADC), decreases the capacity of Trypanosoma cruzi to invade and multiply within different types of mammalian host cells in vitro. In this work we found that inhibition of intracellular growth results from selective impairment of amastigote division without appreciable alteration of the capacity of the invading trypomastigotes to transform into the replicative amastigote form. Addition of agmatine, the product of arginine decarboxylation, reversed the inhibitory effect of DFMA. Inhibition of ornithine decarboxylase activity by DL-alpha-difluoromethylornithine present in the medium prior to and during infection did not affect trypomastigote transformation or amastigote replication and did not change the magnitude of the inhibitory effect of DFMA on parasite multiplication. Hence, neither polyamine synthesis via the ornithine decarboxylase pathway nor salvage of host cell polyamines by T. cruzi appeared to be a likely explanation for the normal rate of parasite transformation that was seen in the presence of DFMA. Two clones of T. cruzi, TMSU-1 and TMSU-2, were tested for their degrees of sensitivity to the inhibitory effects of DFMA. Both trypomastigote association with (i.e., binding to and penetration of) myoblasts, and intracellular amastigote multiplication by either clone were found to be significantly (P less than 0.05) but not completely inhibited by DFMA. Therefore, the partial inhibition of T. cruzi infectivity and replication caused by DFMA is unlikely to represent a composite of effects of the drug on DFMA-sensitive and insensitive clones.(ABSTRACT TRUNCATED AT 250 WORDS)

  5. Analysis Results for ARRA Projects: Enabling Fuel Cell Market Transformation (Presentation)

    Energy Technology Data Exchange (ETDEWEB)

    Kurtz, J.; Wipke, K.; Sprik, S.; Ramsden, T.; Ainscough, C.; Saur, G.

    2012-06-01

    This presentation discusses analysis results for American Recovery and Reinvestment Act early market fuel cell deployments and describes the objective of the project and its relevance to the Department of Energy Hydrogen and Fuel Cells Program; NREL's analysis approach; technical accomplishments including publication of a fourth set of composite data products; and collaborations and future work.

  6. Effects of enamel matrix derivative and transforming growth factor-β1 on human osteoblastic cells

    Directory of Open Access Journals (Sweden)

    Rosa Adalberto L

    2011-07-01

    Full Text Available Abstract Background Extracellular matrix proteins are key factors that influence the regenerative capacity of tissues. The objective of the present study was to evaluate the effects of enamel matrix derivative (EMD, TGF-β1, and the combination of both factors (EMD+TGF-β1 on human osteoblastic cell cultures. Methods Cells were obtained from alveolar bone of three adult patients using enzymatic digestion. Effects of EMD, TGF-β1, or a combination of both were analyzed on cell proliferation, bone sialoprotein (BSP, osteopontin (OPN and alkaline phosphatase (ALP immunodetection, total protein synthesis, ALP activity and bone-like nodule formation. Results All treatments significantly increased cell proliferation compared to the control group at 24 h and 4 days. At day 7, EMD group showed higher cell proliferation compared to TGF-β1, EMD + TGF-β1 and the control group. OPN was detected in the majority of the cells for all groups, whereas fluorescence intensities for ALP labeling were greater in the control than in treated groups; BSP was not detected in all groups. All treatments decreased ALP levels at 7 and 14 days and bone-like nodule formation at 21 days compared to the control group. Conclusions The exposure of human osteoblastic cells to EMD, TGF-β1 and the combination of factors in vitro supports the development of a less differentiated phenotype, with enhanced proliferative activity and total cell number, and reduced ALP activity levels and matrix mineralization.

  7. PARTIAL DELTETION OF p53 GENE IN α PARTICLE-INDUCED TRANSFORMANT OF SYRIAN HAMSTER EMBRYO CELLS

    Institute of Scientific and Technical Information of China (English)

    寿江; 章扬培; 吴德昌

    1996-01-01

    The mutation of p53 gene was detected in Syrian hamster embryo (SHE) cells neoplastically ilfitlatedwith a parties. The level of the p53 mRNA in transformant was obviously higher than that in non-irradiated eounterpm, as measured by Northern blot analysis of total RNA. A pair of primers were designedbased on p53 cDNA sequence to produce the whole length of coding sequence about 1.2 kilobase (Kb) byreverse transcription of mRNA followed by the polymerase chain reaction (RT-PCR), but the length of fragment amplified from transnormant mRNA was about 0. 3Kb, remarkably shorter than that from nor-real SHE cells. Immunohistcchemical analysis of p53 protein showed that no heavy staining was found onslice of tumor derived from transformant inoculated in nude mice with hamster specific p53 monocloned antibody HD200. The results implied that p53 gene had been mutated by deletion, which might lead to lces of p53 protein expression but the increased expression of p53 remained in a particle-induced SHE tranalormant.

  8. Induction of iodide uptake in transformed thyrocytes: a compound screening in cell lines

    Energy Technology Data Exchange (ETDEWEB)

    Froehlich, Eleonore [University of Tuebingen, Department of Endocrinology, Metabolism, Nephrology and Clinical Chemistry, Internal Medicine, Tuebingen (Germany); Brossart, Peter [University of Tuebingen, Department of Haematology, Oncology, Immunology and Rheumatology, Internal Medicine, Tuebingen (Germany); Wahl, Richard [University of Tuebingen, Department of Endocrinology, Metabolism, Nephrology and Clinical Chemistry, Internal Medicine, Tuebingen (Germany); Department IV, Internal Medicine, Tuebingen (Germany)

    2009-05-15

    Retinoic acid presently is the most advanced agent able to improve the efficacy of radioiodine therapy in differentiated thyroid carcinoma. In order to identify compounds with higher efficacy a panel of pharmacologically well-characterized compounds with antitumour action in solid cancer cell lines was screened. The effects of the compounds on iodide uptake, cell number, proliferation and apoptosis were evaluated. In general, compounds were more effective in cell lines derived from more aggressive tumours. The effectiveness in terms of number of responsive cell lines and maximal increase in iodide uptake achieved decreased in the order: APHA > valproic acid {approx} sirolimus {approx} arsenic trioxide > retinoic acid {approx} lovastatin > apicidine {approx} azacytidine {approx} retinol {approx} rosiglitazone {approx} bortezomib. We hypothesize that testing of cells from primary tumours or metastases in patients may be a way to identify compounds with optimum therapeutic efficacy for individualized treatment. (orig.)

  9. Production of antigen-specific suppressive T cell factor by radiation leukemia virus-transformed suppressor T cells

    International Nuclear Information System (INIS)

    Hen egg-white lysozyme-specific suppressor T cells induced in C57BL/6 mice have been selected by sequential passage over plates coated with goat anti-mouse Ig and HEL. These suppressor T cells, 80% I-J+, were infected in vitro with radiation leukemia virus and injected intravenously into sublethally irradiated syngeneic recipients. After 4 to 6 months, 6 out of 20 injected mice developed thymic lymphomas, which were maintained by transplantation into histocompatible hosts and subsequently established as permanent cell lines. Cells of these six thymomas were screened for the presence of Thy 1.2, Lyt 1, Lyt 2, I-J/sup b/, and Ig cell surface antigens by direct or indirect immunofluorescence. One tumor was found to express the expected phenotype of suppressor T cells. High-speed supernatants of extracts obtained from L4 cells were able to induce HEL-specific suppression in a T cell proliferative assay, demonstrating the presence of an antigen-specific suppressive T cell factor

  10. Transforming Growth Factor-beta signal responding in hepatic stem-like cells

    Institute of Scientific and Technical Information of China (English)

    CUI Wei

    2008-01-01

    Objective To investigate the effects of TGF-β on the expressions and distribution of phosphorated Smad2/3 and Smad7 in hepatic stem-like cells. Methods Using immunogold transmission electron microscopy, we observed the expressions and distribution of phosphorated Smad2/3, and Smad7 before and after TGF-β1 (5 ng·mL-1) treatment for 4, 8, and 24 hours in hepatic stem-like cells (WB cells). In addition, we also detected the apoptosis status after TGF-β1 stimulation by transmission electron microscopy. Results TGF-β1 stimulation can result in expression increasing of phosphorated Smad2/3 in WB cells, and reach the peak at 8 h, especially in the nuclear. After treatment with TGF-β1 for 24 h, the nuclear expression of phosphorated Smad2/3 gradually decreased. Additionally, we found that TGF-β1 treatment also contributed to increasing in protein level and alteration in cellular distribution of Smad7 (translocation from the nucleus to the cytoplasm) in WB cells. Furthermore, we observed apoptotic body in WB cells after TGF-β1 treatment for 8 h. Conclusions These results indicate that TGF-β stimulation can alter the expression and cellular distribution of phosphorated Srnad2/3 and Smad7 which are its downstream molecular, suggesting hepatic stem-like cells own intact responding to TGF-β.

  11. Transformation of MCF-10A cells by random mutagenesis with frameshift mutagen ICR191: A model for identifying candidate breast-tumor suppressors

    Directory of Open Access Journals (Sweden)

    Matsui Sei-Ichi

    2008-06-01

    Full Text Available Abstract Background Widely accepted somatic mutation theory of carcinogenesis states that mutations in oncogenes and tumor suppressor genes in genomes of somatic cells is the cause of neoplastic transformation. Identifying frequent mutations in cancer cells suggests the involvement of mutant genes in carcinogenesis. Results To develop an in vitro model for the analysis of genetic alterations associated with breast carcinogenesis, we used random mutagenesis and selection of human non-tumorigenic immortalized breast epithelial cells MCF-10A in tissue-culture conditions that mimic tumor environment. Random mutations were generated in MCF-10A cells by cultivating them in a tissue-culture medium containing the frameshift-inducing agent ICR191. The first selective condition we used to transform MCF1-10A cells was cultivation in a medium containing mutagen at a concentration that allowed cell replication despite p53 protein accumulation induced by mutagen treatment. The second step of selection was either cell cultivation in a medium with reduced growth-factor supply or in a medium that mimics a hypoxia condition or growing in soft agar. Using mutagenesis and selection, we have generated several independently derived cultures with various degrees of transformation. Gene Identification by Nonsense-mediated mRNA decay Inhibition (GINI analysis has identified the ICR191-induced frameshift mutations in the TP53, smoothelin, Ras association (RalGDS/AF-6 domain family 6 (RASSF6 and other genes in the transformed MCF-10A cells. The TP53 gene mutations resulting in the loss of protein expression had been found in all independently transformed MCF-10A cultures, which form large progressively growing tumors with sustained angiogenesis in nude mice. Conclusion Identifying genes containing bi-allelic ICR191-induced frameshift mutations in the transformed MCF-10A cells generated by random mutagenesis and selection indicates putative breast-tumor suppressors. This

  12. Spontaneous transformation of murine oviductal epithelial cells: A model system to investigate the onset of fallopian-derived tumors

    Directory of Open Access Journals (Sweden)

    MIchael P. Endsley

    2015-07-01

    Full Text Available High-grade serous carcinoma (HGSC is the most lethal ovarian cancer histotype. The fallopian tube secretory epithelial cells (FTSECs are a proposed progenitor cell type. Genetically altered FTSECs form tumors in mice; however, a spontaneous HGSC model has not been described. Apart from a subpopulation of genetically predisposed women, most women develop ovarian cancer spontaneously, which is associated with aging and lifetime ovulations. A murine oviductal cell line (MOELOW was developed and continuously passaged in culture to mimic cellular aging (MOEHIGH. The MOEHIGH cellular model exhibited a loss of acetylated tubulin consistent with an outgrowth of secretory epithelial cells in culture. MOEHIGH cells proliferated significantly faster than MOELOW, and the MOEHIGH cells produced more 2D foci and 3D soft agar colonies as compared to MOELOW. MOEHIGH were xenografted into athymic female nude mice both in the subcutaneous and the intraperiteonal compartments. Only the subcutaneous grafts formed tumors that were negative for cytokeratin, but positive for oviductal markers such as oviductal glycoprotein 1 and Pax8. These tumors were considered to be poorly differentiated carcinoma. The differential molecular profiles between MOEHIGH and MOELOW were determined using RNA-Seq and confirmed by protein expression to uncover pathways important in transformation, like the p53 pathway, the FOXM1 pathway, WNT signaling, and splicing. MOEHIGH had enhanced protein expression of c-myc, Cyclin E, p53 and FOXM1 with reduced expression of p21. MOEHIGH were also less sensitive to cisplatin and DMBA, which induce lesions typically repaired by base-excision repair. A model of spontaneous tumorogenesis was generated starting with normal oviductal cells. Their transition to cancer involved alterations in pathways associated with high-grade serous cancer in humans.

  13. Transforming growth factor-beta mediates intestinal healing and susceptibility to injury in vitro and in vivo through epithelial cells.

    Science.gov (United States)

    Beck, Paul L; Rosenberg, Ian M; Xavier, Ramnik J; Koh, Theodore; Wong, Josée F; Podolsky, Daniel K

    2003-02-01

    In vitro studies suggest that transforming growth factor (TGF)-beta has potent effects on gastrointestinal mucosal integrity, wound repair, and neoplasia. However, the multiplicity of actions of this peptide on many different cell types confounds efforts to define the role of TGF-beta within the intestinal epithelium in vivo. To delineate these effects selective blockade of intestinal epithelial TGF-beta activity was undertaken through targeted expression of a dominant-negative (DN) TGF-beta RII to intestinal epithelial cells in vitro and in vivo. Stable intestinal epithelial cell (IEC)-6 lines overexpressing TGF-beta RII-DN (nucleotides -7 to 573) were established. Transgenic mice overexpressing TGF-beta RII-DN under the regulation of a modified liver fatty acid-binding promoter (LFABP-PTS4) were constructed. In vitro healing was assessed by wounding of confluent monolayers. Colitis was induced by the addition of dextran sodium sulfate (2.5 to 7.5% w/v) to their drinking water. Overexpression of TGF-beta RII-DN in intestinal epithelial cell-6 cells resulted in a marked reduction in cell migration and TGF-beta-stimulated wound healing in vitro. TGF-beta RII-DN transgenic mice did not exhibit baseline intestinal inflammation or changes in survival, body weight, epithelial cell proliferation, aberrant crypt foci, or tumor formation. TGF-beta RII-DN mice were markedly more susceptible to dextran sodium sulfate-induced colitis and exhibited impaired recovery after colonic injury. TGF-beta is required for intestinal mucosal healing and TGF-beta modulation of the intestinal epithelium plays a central role in determining susceptibility to injury. PMID:12547717

  14. Agmatine protects retinal ganglion cells from hypoxia-induced apoptosis in transformed rat retinal ganglion cell line

    Directory of Open Access Journals (Sweden)

    Kim Chan

    2007-10-01

    Full Text Available Abstract Background Agmatine is an endogenous polyamine formed by the decarboxylation of L-arginine. We investigated the protective effects of agmatine against hypoxia-induced apoptosis of immortalized rat retinal ganglion cells (RGC-5. RGC-5 cells were cultured in a closed hypoxic chamber (5% O2 with or without agmatine. Cell viability was determined by lactate dehydrogenase (LDH assay and apoptosis was examined by annexin V and caspase-3 assays. Expression and phosphorylation of mitogen-activated protein kinases (MAPKs; JNK, ERK p44/42, and p38 and nuclear factor-kappa B (NF-κB were investigated by Western immunoblot analysis. The effects of agmatine were compared to those of brain-derived neurotrophic factor (BDNF, a well-known protective neurotrophin for retinal ganglion cells. Results After 48 hours of hypoxic culture, the LDH assay showed 52.3% cell loss, which was reduced to 25.6% and 30.1% when agmatine and BDNF were administered, respectively. This observed cell loss was due to apoptotic cell death, as established by annexin V and caspase-3 assays. Although total expression of MAPKs and NF-κB was not influenced by hypoxic injury, phosphorylation of these two proteins was increased. Agmatine reduced phosphorylation of JNK and NF-κB, while BDNF suppressed phosphorylation of ERK and p38. Conclusion Our results show that agmatine has neuroprotective effects against hypoxia-induced retinal ganglion cell damage in RGC-5 cells and that its effects may act through the JNK and NF-κB signaling pathways. Our data suggest that agmatine may lead to a novel therapeutic strategy to reduce retinal ganglion cell injury related to hypoxia.

  15. Telomerase activity: A biomarker of cell proliferation, not malignant transformation

    OpenAIRE

    Belair, Cassandra D.; Yeager, Thomas R.; Lopez, Patricia M.; Reznikoff, Catherine A.

    1997-01-01

    Telomerase activity is readily detected in most cancer biopsies, but not in premalignant lesions or in normal tissue samples with a few exceptions that include germ cells and hemopoietic stem cells. Telomerase activity may, therefore, be a useful biomarker for diagnosis of malignancies and a target for inactivation in chemotherapy or gene therapy. These observations have led to the hypothesis that activation of telomerase may be an important step in tumorigenesis. To test this hypothesis, we ...

  16. The relationship between dose rate and transformation induction in C3H/10T1/2 cells by TRIGA reactor fission neutrons at 0.3 Gy

    International Nuclear Information System (INIS)

    The authors present their own and other data showing dose-effect relations for cell survival and the induction of transformations in C3H/IOT 1/2 cells in exponential or stationary cultures after a range of high dose-rate irradiations with X-rays or AFRRI neutrons. (UK)

  17. 36. Study on p16INK4a and p15INK4b genes of human bronchial epithelial cells malignantly transformed by cyclophosphamide and thiotepa

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@Transformed human bronchial epithelial cells BEAS-2B induced by CP and TEPA were used to study abnormity of the tumor suppressor genes p15INK4b and p16INK4a, through which we can provide clues for explanations of the molecular mechanism in carcinogenesis of human bronchial epithelial cells induced by CP and TEPA. Analysis of the genomic DNA from the transformed BEAS-CP, and BEAS-T cells using PCR amplification, singe strand conformation polymorphism(SSCP) and DNA sequencing

  18. Small tumor virus genomes are integrated near nuclear matrix attachment regions in transformed cells.

    Science.gov (United States)

    Shera, K A; Shera, C A; McDougall, J K

    2001-12-01

    More than 15% of human cancers have a viral etiology. In benign lesions induced by the small DNA tumor viruses, viral genomes are typically maintained extrachromosomally. Malignant progression is often associated with viral integration into host cell chromatin. To study the role of viral integration in tumorigenesis, we analyzed the positions of integrated viral genomes in tumors and tumor cell lines induced by the small oncogenic viruses, including the high-risk human papillomaviruses, hepatitis B virus, simian virus 40, and human T-cell leukemia virus type 1. We show that viral integrations in tumor cells lie near cellular sequences identified as nuclear matrix attachment regions (MARs), while integrations in nonneoplastic cells show no significant correlation with these regions. In mammalian cells, the nuclear matrix functions in gene expression and DNA replication. MARs play varied but poorly understood roles in eukaryotic gene expression. Our results suggest that integrated tumor virus genomes are subject to MAR-mediated transcriptional regulation, providing insight into mechanisms of viral carcinogenesis. Furthermore, the viral oncoproteins serve as invaluable tools for the study of mechanisms controlling cellular growth. Similarly, our demonstration that integrated viral genomes may be subject to MAR-mediated transcriptional effects should facilitate elucidation of fundamental mechanisms regulating eukaryotic gene expression.

  19. Active Erk Regulates Microtubule Stability in H-ras-Transformed Cells

    Directory of Open Access Journals (Sweden)

    Rene E. Harrison

    2001-01-01

    Full Text Available Increasing evidence suggests that activated erk regulates cell functions, at least in part, by mechanisms that do not require gene transcription. Here we show that the map kinase, erk, decorates microtubules (MTs and mitotic spindles in both parental and mutant active rastransfected 10T1 /2 fibroblasts and MCF10A breast epithelial cells. Approximately 20% of total cellular erk decorated MTs in both cell lines. A greater proportion of activated erk was associated with MTs in the presence of mutant active H-ras than in parental cells. Activation of erk by the ras pathway coincided with a decrease in the stability of MT, as detected by a stability marker. The MKK1 inhibitor, PD98059 and transfection of a dominant negative MKK1 blocked ras-induced instability of MTs but did not modify the association of erk with MTs or affect MT stability of the parental cells. These results indicate that the subset of active erk kinase that associates with MTs contributes to their instability in the presence of a mutant active ras. The MT-associated subset of active erk likely contributes to the enhanced invasive and proliferative abilities of cells containing mutant active H-ras.

  20. Transformation of primary human embryonic kidney cells to anchorage independence by a combination of BK virus DNA and the Harvey-ras oncogene

    International Nuclear Information System (INIS)

    Primary human embryonic kidney (HEK) cells were transformed by a focus assay with BK virus (BKV) DNA molecularly cloned at its unique EcoRI site. Both viral DNA sequences and viral tumor antigens were present and expressed in all the foci that the authors examined. However, cells isolated from foci were incapable of growth in soft agar. They then examined the transformation of HEK cells after their transfection with a combination of BKV DNA and either the normal or the activated form of the human Ha-ras oncogene (EJ c-Ha-ras-1). Only the cells transfected with a combination of BKV DNA and the activated form of Ha-ras DNAs were present in the transformed colonies. BKV tumor antigens and the Ha-ras p21 protein were also expressed

  1. High Fuel Utilization in Solid Oxide Fuel Cells: Experimental Characterization and Data Analysis with Continuous Wavelet Transform

    Science.gov (United States)

    Esposito, Angelo; Russo, Luigi; Kändler, Christoph; Pianese, Cesare; Ludwig, Bastian; Steiner, Nadia Yousfi

    2016-06-01

    The on-line diagnostics of Solid Oxide Fuel Cells (SOFCs) is a critical tool to achieve optimal performance and extend the lifetime. The Continuous Wavelet Transform (CWT) methodology was applied to the SOFC voltage signal to detect signatures that reveal the presence of a fault in the cell/stack. The selected fault was anode re-oxidation caused by high Fuel Utilization (FU) (higher then nominal). To experimentally emulate the high FU faults, a standard test procedure was developed, which was used to characterize a μ-CHP system at high FU operation. To complete the analysis, data collected on Single Cells were exploited too. The CWT was applied to the voltage signal for each FU level to verify the qualitative difference (signature) between the signals at different FU's within the same tests as well as the correspondence between the same conditions over different tests. A statistical study was performed to quantify the observed differences and to determine the correspondence between CWT coefficients and operating conditions. The approach proves to be suitable to diagnose high FU in SOFC, showing a successful detection rate above 76%. The results show the good potential of using the CWT methodology as diagnostic tools for SOFCs from cell to stack level.

  2. Osteogenic Potential of Cultured Bone Marrow Stromal CellsTransfected with Transforming Growth Factor β1 Gene in vitro

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    To study the osteogenic potential of cultured bone marrow stromal cells (BMSCs) transfected with transforming growth factor β1 (TGF-β1) gene in vitro, cultured BMSCs were transfected with the complexes of pcDNA3-TGF-β1 and Lipofectamine Reagent in vitro. The cell proliferation was detected by MTT method and the morphological features of transfected BMSCs was observed. ALP stains and PNP method were used to measure ALP activity. In addition, the collagen type Ⅰ propeptides and mineralized matrixes were examined by immunohistochemical staining and tetracycline fluorescence labeling respectively. The morphological and biological characters of the transfected BMSCs were similar to those of osteoblasts and the cell proliferation was promoted. The cell layer displayed strong positive reaction for ALP stains and immunohistochemical staining. ALP activity and collagen type Ⅰ expression increased remarkably after transfection. Mineralized matrixes formed earlier and more in transfected BMSCs as compared with control group. It is concluded that transfecting with TGF-β1 gene could promote the osteogenic potential of cultured BMSCs.

  3. Triple-phase dynamic MRI: A new clue to predict malignant transformation of giant cell tumor of bone

    International Nuclear Information System (INIS)

    Objective: Our purpose was, through the comparison of the characteristics of time–intensity curve on triple-phase dynamic contrast-enhanced MRI among groups of giant cell tumor of bone (GCTB), recurrent benign giant cell tumor of bone (RBGCTB), and secondary malignant giant cell tumor of bone (SMGCTB), to find clues to predict the malignant transformation of GCTB. Subjects and methods: 21 patients diagnosed as GCTB were included in this study. All cases took recurrence after intralesional curettage. 9 cases were confirmed as SMGCTB and 12 cases were confirmed as RBGCTB. Cases were divided into four groups: group A, GCTB (n = 9); group B, SMGCTB (n = 9); group C, GCTB (n = 12); group D, RBGCTB (n = 12). Enhancement index(EI) of lesions on DCEMRI was calculated using formula: EI(t) = [S(t) − S(0)]/S(0), where S(0) was signal intensity of lesion on non-contrast-enhanced T1-weighted images and S(t) was signal intensity of lesion on DCEMRI (t = 30, 60, 180 s). Enhancement index of each group in each phase was compared using One-Way ANOVA analysis. Slope values of time–intensity curve were compared by the same way. Results: Time–intensity curve of SMGCTB was characterized by a steep upward slope followed by an early and rapid washout phase. Time–intensity curve of GCTB and RBGCTB was characterized by a steep slope followed by a relatively slow washout phase. No significant difference in enhancement index was found in the first phase (p > 0.05). There was significant difference in the second and the third phase (p < 0.05). Enhancement index of group B (SMGCTB) was smaller. There was no difference in rising slope value (p > 0.05). Conclusions: Dynamic contrast-enhanced MRI appears a helpful method to find new clues to predict malignant transformation of GCTB

  4. The Cain and Abl of epithelial-mesenchymal transition and transforming growth factor-β in mammary epithelial cells.

    Science.gov (United States)

    Allington, Tressa M; Schiemann, William P

    2011-01-01

    Transforming growth factor-β (TGF-β) normally inhibits breast cancer development by preventing mammary epithelial cell (MEC) proliferation, by inducing MEC apoptosis, and by creating cell microenvironments that maintain MEC homeostasis and prevent their uncontrolled growth and motility. Mammary tumorigenesis elicits dramatic alterations in MEC architecture and microenvironment integrity, which collectively counteract the tumor-suppressing activities of TGF-β and enable its stimulation of breast cancer invasion and metastasis. How malignant MECs overcome the cytostatic actions imposed by normal microenvironments and TGF-β, and how abnormal microenvironments conspire with TGF-β to stimulate the development and progression of mammary tumors remains largely undefined. These knowledge gaps have prevented science and medicine from implementing treatments effective in simultaneously targeting abnormal cellular microenvironments, and in antagonizing the oncogenic activities of TGF-β in developing and progressing breast cancers. c-Abl is a ubiquitously expressed nonreceptor protein tyrosine kinase that essentially oversees all aspects of cell physiology, including the regulation of cell proliferation, migration and adhesion, as well as that of cell survival. Thus, the biological functions of c-Abl are highly reminiscent of those attributed to TGF-β, including the ability to function as either a suppressor or promoter of tumorigenesis. Interestingly, while dysregulated Abl activity clearly promotes tumorigenesis in hematopoietic cells, an analogous role for c-Abl in regulating solid tumor development, including those of the breast, remains controversial. Here, we review the functions of c-Abl in regulating breast cancer development and progression, and in alleviating the oncogenic activities of TGF-β and its stimulation of epithelial-mesenchymal transition during mammary tumorigenesis.

  5. Bone morphogenetic protein 2 promotes transforming growth factor β3-induced chondrogenesis of human osteoarthritic synovium-derived stem cells

    Institute of Scientific and Technical Information of China (English)

    RUI Yun-feng; DU Lin; WANG You; WANG Yang; LUI Pauline po-yee; TANG Ting-ting; CHAN Kai-ming; DAI Ke-rong

    2010-01-01

    Background Synovium-derived stem cells (SDSCs) with higher chondrogenic potential are attracting considerable attention as a cell source for cartilage regeneration. We investigated the effect of bone morphogenetic protein 2 (BMP-2) on transforming growth factor beta3 (TGF-β3)-induced chondrogenesis of SDSCs isolated from human osteoarthritic synovium in a pellet culture system. Methods The clonogenicity, stem cell marker expression and multi-differentiation potential of isolated SDSCs were determined by colony forming unit assay, flow cytometry and specific staining including alizarin red S, Oil red O and alcian blue staining, respectively. SDSCs pellet was cultured in chondrogenic medium with or without TGF-β3 or/and BMP-2. At day 21, the diameter and the weight of the pellets were measured. Chondrogenic differentiation of SDSCs was evaluated by Safranin O staining, immunohistochemical staining of collagen type Ⅱ, sulfated glycosaminoglycan (sGAG) synthesis and mRNA expression of collagen type Ⅱ, aggrecan, SOX9, link-protein, collagen type X and BMP receptor Ⅱ. Results Cells isolated under the optimized culturing density (104/60 cm2) showed clonogenicity and multi-differentiation potential. These cells were positive (>99%) for CD44, CD90, CD105 and negative (<10%) for CD34 and CD71. SDSCs differentiated to a chondrocytic phenotype in chondrogenic medium containing TGF-β3 with or without BMP-2. Safranin O staining of the extracellular matrix was positive and the expression of collagen type Ⅱ was detected. Cell pellets treated with TGF-β3 and BMP-2 were larger in diameter and weight, produced more sGAGs, and expressed higher levels of collagen type Ⅱ and other chondrogenic markers, except COL10A1, than medium with TGF-β3 alone. Conclusions SDSCs could be isolated from human osteoarthritic synovium. Supplementation with BMP-2 significantly promoted the in vitro TGF-β3-induced chondrogenic differentiation of SDSCs.

  6. Naturally Occurring Variants of Human A9 Nicotinic Receptor Differentially Affect Bronchial Cell Proliferation and Transformation

    OpenAIRE

    Chikova, Anna; Grando, Sergei A.

    2011-01-01

    Isolation of polyadenilated mRNA from human immortalized bronchial epithelial cell line BEP2D revealed the presence of multiple isoforms of RNA coded by the CHRNA9 gene for α9 nicotinic acetylcholine receptor (nAChR). BEP2D cells were homozygous for the rs10009228 polymorphism encoding for N442S amino acid substitution, and also contained mRNA coding for several truncated isoforms of α9 protein. To elucidate the biologic significance of the naturally occurring variants of α9 nAChR, we compare...

  7. Two nuclear oncogenic proteins, P135gag-myb-ets and p61/63myc, cooperate to induce transformation of chicken neuroretina cells.

    OpenAIRE

    Amouyel, P; Laudet, V; P. Martin; Li, R P; Quatannens, B; Stéhelin, D; Saule, S.

    1989-01-01

    Several studies have shown that full transformation of primary rodent fibroblasts can be achieved in vitro through the cooperation of two oncogenes (usually one nuclear and one cytoplasmic) classified on the basis of different complementation groups. We have shown previously that cooperation between v-mil (cytoplasmic, serine-threonine kinase product), and v-myc (nuclear, DNA-binding product) is required to transform 7-day-old chicken neuroretina cells, which in usual culture medium do not ra...

  8. Ribosomal protein S6 phosphorylation and morphological changes in response to the tumour promoter 12-O-tetradecanoylphorbol 13-acetate in primary human tumour cells, established and transformed cell lines

    DEFF Research Database (Denmark)

    Rance, A J; Thönnes, M; Issinger, O G

    1985-01-01

    The phosphorylation of ribosomal protein S6 in fibroblasts, primary human tumour cells, established and SV40-transformed human cell lines was compared after the addition of 12-O-tetradecanoylphorbol 13-acetate (TPA). In fibroblasts and primary tumour cell cultures, stimulation of S6 phosphorylati...

  9. Neoplastic transformation of human breast epithelial cells by estrogens and chemical carcinogens.

    Science.gov (United States)

    Russo, Jose; Tahin, Quivo; Lareef, M Hasan; Hu, Yun-Fu; Russo, Irma H

    2002-01-01

    Sporadic breast cancer, the most common cancer diagnosed in American and Northern European women, is gradually increasing in incidence in most Western countries. Prevention would be the most efficient way of eradicating this disease. This goal, however, cannot be accomplished until the specific agent(s) or mechanisms that initiate the neoplastic process are identified. Experimental studies have demonstrated that mammary cancer is a hormone-dependent multistep process that can be induced by a variety of compounds and mechanisms, that is, hormones, chemicals, radiation, and viruses, in addition to or in combination with genetic factors. Although estrogens have been shown to play a central role in breast cancer development, their carcinogenicity on human breast epithelial cells (HBECs) has not yet been clearly demonstrated. Breast cancer initiates in the undifferentiated lobules type 1, which are composed of three cell types: highly proliferating cells that are estrogen-receptor negative (ER-), nonproliferating cells that are ER positive (ER+), and very few (17p13.2. The relevance of these findings is highlighted by the observation that E(2)- and B[a]P-induced genomic alterations in the same loci found in ductal hyperplasia, ductal carcinoma in situ, and invasive ductal carcinoma of the breast. PMID:11921196

  10. Bleomycin resistance : a new dominant selectable marker for plant cell transformation

    NARCIS (Netherlands)

    Hille, Jacques; Verheggen, Frank; Roelvink, Peter; Franssen, Henk; Kammen, Ab van; Zabel, Pim

    1986-01-01

    Plant cells are sensitive to the antibiotic bleomycin, a DNA damaging glycopeptide. A bleomycin resistance determinant, located on transposon Tn5 and functional in bacteria, has been cloned in a plant expression vector and introduced into Nicotiana plumbaginifolia using Agrobacterium tumefaciens. Th

  11. Investigating Processes of Nanocrystal Formation and Transformation via Liquid Cell TEM

    DEFF Research Database (Denmark)

    Nielsen, Michael H.; Li, Dongsheng; Zhang, Hengzhong;

    2014-01-01

    and spatial resolution of experimental techniques that can observe dynamic processes in a bulk solution. Here we report results from liquid cell transmission electron microscopy studies of nucleation and growth of Au, CaCO3, and iron oxide nanoparticles. We show how these in situ data can be used to obtain...

  12. Antigen receptors and somatic hypermutation in B-cell chronic lymphocytic leukemia with Richter's transformation

    NARCIS (Netherlands)

    L.A. Smit; F. van Maldegem; A.W. Langerak; C.E. van der Schoot; M.J. de Wit; S. Bea; E. Campo; R.J. Bende; C.J.M. van Noesel

    2006-01-01

    Background and Objectives. Activation-induced cytidine deaminase is essential for somatic hypermutation and class switch recombination of the immunoglobulin genes in B cells. It has been proposed that aberrant targeting of the somatic hypermutation machinery is instrumental in initiation and progres

  13. Role of Streptococcus sanguis (strain Wicky) cell surface-located deoxyribonucleic acid-binding factor in transformation of a homologous strain.

    OpenAIRE

    Cegłowski, P; Kawczyński, M; Dobrzański, W T

    1981-01-01

    In a previous report we demonstrated the presence of a factor binding deoxyribonucleic acid (DNA) in vitro (BF) in cell leakage fluids from transformable Streptococcus sanguis strains Wicky, Challis, and Blackburn. BF originating from strain Wicky was purified to homogeneity, and its properties are described. In this work, it was found that BF occurs at the surface of Wicky cells in two forms, loosely bound (LB-BF) and strongly bound to the cell envelope. It was demonstrated that LB-BF formed...

  14. Epithelial Cell Transforming 2 and Aurora Kinase B Modulate Formation of Stress Granule-Containing Transcripts from Diverse Cellular Pathways in Astrocytoma Cells.

    Science.gov (United States)

    Weeks, Adrienne; Agnihotri, Sameer; Lymer, Jennifer; Chalil, Alan; Diaz, Roberto; Isik, Semra; Smith, Christian; Rutka, James T

    2016-06-01

    Stress granules are small RNA-protein granules that modify the translational landscape during cellular stress to promote survival. The RhoGTPase RhoA is implicated in the formation of RNA stress granules. Our data demonstrate that the cytokinetic proteins epithelial cell transforming 2 and Aurora kinase B (AurkB) are localized to stress granules in human astrocytoma cells. AurkB and its downstream target histone-3 are phosphorylated during arsenite-induced stress. Chemical (AZD1152-HQPA) and siRNA inhibition of AurkB results in fewer and smaller stress granules when analyzed using high-throughput fluorescent-based cellomics assays. RNA immunoprecipitation with the known stress granule aggregates TIAR and G3BP1 was performed on astrocytoma cells, and subsequent analysis revealed that astrocytoma stress granules harbor unique mRNAs for various cellular pathways, including cellular migration, metabolism, translation, and transcriptional regulation. Human astrocytoma cell stress granules contain mRNAs that are known to be involved in glioma signaling and the mammalian target of rapamycin pathway. These data provide evidence that RNA stress granules are a novel form of epigenetic regulation in astrocytoma cells, which may be targetable by chemical inhibitors and enhance astrocytoma susceptibility to conventional therapy, such as radiation and chemotherapy. PMID:27106762

  15. NIH 3T3 cells malignantly transformed by mot—2 show inactivation and cytoplasmic sequestration of the p53 protein

    Institute of Scientific and Technical Information of China (English)

    WADHWA; SYUICHITAKANO; 等

    1999-01-01

    In previous studies we have reported that a high level of expression of mot-2 protein results in malignant transformation of NIH 3T3 cells as analyzed by anchorage independent growth and nude mice assays [Kaul et al.,Oncogene,17,907-11,1998].Mot-2 was found to interact with tumor suppressor protein p53.The transient overexpression of mot-2 was inhibitory to transcriptional activation function of p53 [Wadhwa et al.,J.Biol.Chem.,273,2958691,1998].We demonstrate here that mot-2 transfected stable clone of NIH 3T3 that showed malignant properties indeed show inactivation of p53 function as assayed by exogenous p53 dependent reporter.The expression level of p53 in response to UV-irradiation was lower in NIH 3T3/mot-2 as compared to NIH 3T3 cells and also exhibited delay in reachingpeak.Furthermore,upon serum starvation p53 was seen to translocate to the nucleus in NIH 3T3,but not in its mot-3 derivative.The data suggests that mot-2 mediated cytoplasmic sequestration and inactivation of p53 may operate,at least in part,for malignant phenotype of NIH 3T3/mot-2 cells.

  16. A tyrosine-rich cell surface protein in the diatom Amphora coffeaeformis identified through transcriptome analysis and genetic transformation.

    Directory of Open Access Journals (Sweden)

    Matthias T Buhmann

    Full Text Available Diatoms are single-celled eukaryotic microalgae that are ubiquitously found in almost all aquatic ecosystems, and are characterized by their intricately structured SiO2 (silica-based cell walls. Diatoms with a benthic life style are capable of attaching to any natural or man-made submerged surface, thus contributing substantially to both microbial biofilm communities and economic losses through biofouling. Surface attachment of diatoms is mediated by a carbohydrate- and protein- based glue, yet no protein involved in diatom underwater adhesion has been identified so far. In the present work, we have generated a normalized transcriptome database from the model adhesion diatom Amphora coffeaeformis. Using an unconventional bioinformatics analysis we have identified five proteins that exhibit unique amino acid sequences resembling the amino acid composition of the tyrosine-rich adhesion proteins from mussel footpads. Establishing the first method for the molecular genetic transformation of A. coffeaeformis has enabled investigations into the function of one of these proteins, AC3362, through expression as YFP fusion protein. Biochemical analysis and imaging by fluorescence microscopy revealed that AC3362 is not involved in adhesion, but rather plays a role in biosynthesis and/or structural stability of the cell wall. The methods established in the present study have paved the way for further molecular studies on the mechanisms of underwater adhesion and biological silica formation in the diatom A. coffeaeformis.

  17. Production of antigen-specific suppressive T cell factor by radiation leukemia virus-transformed suppressor T cells.

    OpenAIRE

    Ricciardi-Castagnoli, P; Doria, G; Adorini, L

    1981-01-01

    Hen egg-white lysozyme (HEL)-specific suppressor T cells induced in C57BL/6 mice have been selected by sequential passage over plates coated with goat anti-mouse Ig and HEL. These suppressor T cells, 80% I-J+, were infected in vitro with radiation leukemia virus (RadLV/Nu1) and injected intravenously into sublethally irradiated syngeneic recipients. After 4-6 months, 6 out of 20 injected mice developed thymic lymphomas, which were maintained by transplantation into histocompatible hosts and s...

  18. Simple, fast, and accurate methodology for quantitative analysis using Fourier transform infrared spectroscopy, with bio-hybrid fuel cell examples.

    Science.gov (United States)

    Mackie, David M; Jahnke, Justin P; Benyamin, Marcus S; Sumner, James J

    2016-01-01

    The standard methodologies for quantitative analysis (QA) of mixtures using Fourier transform infrared (FTIR) instruments have evolved until they are now more complicated than necessary for many users' purposes. We present a simpler methodology, suitable for widespread adoption of FTIR QA as a standard laboratory technique across disciplines by occasional users.•Algorithm is straightforward and intuitive, yet it is also fast, accurate, and robust.•Relies on component spectra, minimization of errors, and local adaptive mesh refinement.•Tested successfully on real mixtures of up to nine components. We show that our methodology is robust to challenging experimental conditions such as similar substances, component percentages differing by three orders of magnitude, and imperfect (noisy) spectra. As examples, we analyze biological, chemical, and physical aspects of bio-hybrid fuel cells.

  19. Effects of Xiaoke granule on transforming growth factor-beta1 expression and proliferation in rat mesangial cells

    Institute of Scientific and Technical Information of China (English)

    JI Xiao-mei; WANG Qian; GONG Mu-xin; DU Yu-qiong; JIA De-xian

    2006-01-01

    @@ Diabetic nephropathy, one of the major causes of death of diabetes patients, is diagnosed as the thickening of glomerular basement membrane and progressive expansion of the glomerular mesangium and tubulointerstitium. Intensive studies have shown that hyperglycemia is the key factor for renal sclerosis which can lead to end-stage renal disease for diabetic patients.1,2 Our previous studies demonstrated that Xiaoke granule can inhibit the progression of diabetic nephropathy. However, its mechanisms remain unknown.3,4 In this study, we found that Xiaoke granule coincidently depresses transforming growth factor-beta1 (TGF-β1)expression and inhibits the effect of high glucose on mesangial cell proliferation. This might suggest that the effect of Xiaoke granule on inhibiting progression of diabetic nephropathy through down-regulating TGF-β1 expression.

  20. Inhibition of dendritic cell migration by transforming growth factor-β1 increases tumor-draining lymph node metastasis

    Directory of Open Access Journals (Sweden)

    Imai Kazuhiro

    2012-01-01

    Full Text Available Abstract Background Transforming growth factor (TGF-β is known to be produced by progressor tumors and to immobilize dendritic cells (DCs within those tumors. Moreover, although TGF-β1 has been shown to promote tumor progression, there is still no direct, in vivo evidence as to whether TGF-β1 is able to directly induce distant metastasis. Methods To address that issue and investigate the mechanism by which TGF-β1 suppresses DC activity, we subdermally inoculated mouse ears with squamous cell carcinoma cells stably expressing TGF-β1 or empty vector (mock. Results The numbers of DCs within lymph nodes draining the resultant TGF-β1-expressing tumors was significantly lower than within nodes draining tumors not expressing TGF-β1. We then injected fluorescently labeled bone marrow-derived dendritic cells into the tumors, and subsequent analysis confirmed that the tumors were the source of the DCs within the tumor-draining lymph nodes, and that there were significantly fewer immature DCs within the nodes draining TGF-β1-expressing tumors than within nodes draining tumors not expressing TGF-β1. In addition, 14 days after tumor cell inoculation, lymph node metastasis occurred more frequently in mice inoculated with TGF-β1 transfectants than in those inoculated with the mock transfectants. Conclusions These findings provide new evidence that tumor-derived TGF-β1 inhibits migration of DCs from tumors to their draining lymph nodes, and this immunosuppressive effect of TGF-β1 increases the likelihood of metastasis in the affected nodes.

  1. Integrative Network Analysis Combined with Quantitative Phosphoproteomics Reveals Transforming Growth Factor-beta Receptor type-2 (TGFBR2) as a Novel Regulator of Glioblastoma Stem Cell Properties.

    Science.gov (United States)

    Narushima, Yuta; Kozuka-Hata, Hiroko; Koyama-Nasu, Ryo; Tsumoto, Kouhei; Inoue, Jun-ichiro; Akiyama, Tetsu; Oyama, Masaaki

    2016-03-01

    Glioblastoma is one of the most malignant brain tumors with poor prognosis and their development and progression are known to be driven by glioblastoma stem cells. Although glioblastoma stem cells lose their cancer stem cell properties during cultivation in serum-containing medium, little is known about the molecular mechanisms regulating signaling alteration in relation to reduction of stem cell-like characteristics. To elucidate the global phosphorylation-related signaling events, we performed a SILAC-based quantitative phosphoproteome analysis of serum-induced dynamics in glioblastoma stem cells established from the tumor tissues of the patient. Among a total of 2876 phosphorylation sites on 1584 proteins identified in our analysis, 732 phosphorylation sites on 419 proteins were regulated through the alteration of stem cell-like characteristics. The integrative computational analyses based on the quantified phosphoproteome data revealed the relevant changes of phosphorylation levels regarding the proteins associated with cytoskeleton reorganization such as Rho family GTPase and Intermediate filament signaling, in addition to transforming growth factor-β receptor type-2 (TGFBR2) as a prominent upstream regulator involved in the serum-induced phosphoproteome regulation. The functional association of transforming growth factor-β receptor type-2 with stem cell-like properties was experimentally validated through signaling perturbation using the corresponding inhibitors, which indicated that transforming growth factor-β receptor type-2 could play an important role as a novel cell fate determinant in glioblastoma stem cell regulation. PMID:26670566

  2. Characterization of hyaluronate binding proteins isolated from 3T3 and murine sarcoma virus transformed 3T3 cells

    Energy Technology Data Exchange (ETDEWEB)

    Turley, E.A.; Moore, D.; Hayden, L.J.

    1987-06-02

    A hyaluronic acid binding fraction was purified from the supernatant media of both 3T3 and murine sarcoma virus (MSV) transformed 3T3 cultures by hyaluronate and immunoaffinity chromatography. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis resolved the hyaluronate affinity-purified fraction into three major protein bands of estimated molecular weight (M/sub r,e/) 70K, 66K, and 56K which contained hyaluronate binding activity and which were termed hyaluronate binding proteins (HABP). Hyaluronate affinity chromatography combined with immunoaffinity chromatography, using antibody directed against the larger HABP, allowed a 20-fold purification of HABP. Fractions isolated from 3T3 supernatant medium also contained additional binding molecules in the molecular weight range of 20K. This material was present in vanishingly small amounts and was not detected with a silver stain or with (/sup 35/S)methionine label. The three protein species isolated by hyaluronate affinity chromatography (M/sub r,e/ 70K, 66K, and 56K) were related to one another since they shared antigenic determinants and exhibited similar pI values. In isocratic conditions, HABP occurred as aggregates of up to 580 kilodaltons. Their glycoprotein nature was indicated by their incorporation of /sup 3/H-sugars. Enzyme-linked immunoadsorbent assay showed they were antigenically distinct from other hyaluronate binding proteins such as fibronectin, cartilage link protein, and the hyaluronate binding region of chondroitin sulfate proteoglycan. The results are discussed with regard both to the functional significance of hyaluronate-cell surface interactions in transformed as well as normal cells and to the relationship of HABP to other reported hyaluronate binding proteins.

  3. Cytotoxic drug sensitivity of Epstein-Barr virus transformed lymphoblastoid B-cells

    Directory of Open Access Journals (Sweden)

    Olah Eva

    2006-11-01

    Full Text Available Abstract Background Epstein-Barr virus (EBV is the causative agent of immunosuppression associated lymphoproliferations such as post-transplant lymphoproliferative disorder (PTLD, AIDS related immunoblastic lymphomas (ARL and immunoblastic lymphomas in X-linked lymphoproliferative syndrome (XLP. The reported overall mortality for PTLD often exceeds 50%. Reducing the immunosuppression in recipients of solid organ transplants (SOT or using highly active antiretroviral therapy in AIDS patients leads to complete remission in 23–50% of the PTLD/ARL cases but will not suffice for recipients of bone marrow grafts. An additional therapeutic alternative is the treatment with anti-CD20 antibodies (Rituximab or EBV-specific cytotoxic T-cells. Chemotherapy is used for the non-responding cases only as the second or third line of treatment. The most frequently used chemotherapy regimens originate from the non-Hodgkin lymphoma protocols and there are no cytotoxic drugs that have been specifically selected against EBV induced lymphoproliferative disorders. Methods As lymphoblastoid cell lines (LCLs are well established in vitro models for PTLD, we have assessed 17 LCLs for cytotoxic drug sensitivity. After three days of incubation, live and dead cells were differentially stained using fluorescent dyes. The precise numbers of live and dead cells were determined using a custom designed automated laser confocal fluorescent microscope. Results Independently of their origin, LCLs showed very similar drug sensitivity patterns against 29 frequently used cytostatic drugs. LCLs were highly sensitive for vincristine, methotrexate, epirubicin and paclitaxel. Conclusion Our data shows that the inclusion of epirubicin and paclitaxel into chemotherapy protocols against PTLD may be justified.

  4. Transformation of human osteoblast cells to the tumorigenic phenotype by depleted uranium-uranyl chloride.

    OpenAIRE

    Miller, A C; Blakely, W F; Livengood, D; Whittaker, T; Xu, J.; Ejnik, J W; Hamilton, M. M.; Parlette, E; John, T S; Gerstenberg, H M; Hsu, H

    1998-01-01

    Depleted uranium (DU) is a dense heavy metal used primarily in military applications. Although the health effects of occupational uranium exposure are well known, limited data exist regarding the long-term health effects of internalized DU in humans. We established an in vitro cellular model to study DU exposure. Microdosimetric assessment, determined using a Monte Carlo computer simulation based on measured intracellular and extracellular uranium levels, showed that few (0.0014%) cell nuclei...

  5. Telomerase extends the lifespan of virus-transformed human cells without net telomere lengthening

    OpenAIRE

    Zhu, Jiyue; Wang, He; Bishop, J. Michael; Elizabeth H. Blackburn

    1999-01-01

    Human fibroblasts whose lifespan in culture has been extended by expression of a viral oncogene eventually undergo a growth crisis marked by failure to proliferate. It has been proposed that telomere shortening in these cells is the property that limits their proliferation. Here we report that ectopic expression of the wild-type reverse transcriptase protein (hTERT) of human telomerase averts crisis, at the same time reducing the frequency of dicentric and abnormal chromosomes. Surprisingly, ...

  6. Formalization of the input/output retinal transformation regarding non-standard ganglion cells behavior

    OpenAIRE

    Teftef, Elaa; Viéville, Thierry

    2012-01-01

    National audience; We propose to implement the computational principles raised by the study on the K-cells of the retina using a variational specification of the visual front-end, with an important consequence: In such a framework, the GC are not to be considered individually, but as a network, yielding a mesoscopic view of the retinal processWe consider this visual event detection mechanism to be based on image segmentation and specific natural statistical recognition, including temporal pat...

  7. Non intrusive diagnosis of polymer electrolyte fuel cells by wavelet packet transform

    OpenAIRE

    Steiner, N.; Hissel, D.; MOCOTEGUY, Philippe; Candusso, Denis

    2011-01-01

    Fuel cell is a promising technology for both automotive and stationary applications. However, its reliability and its lifetime remain major hurdles to its wide access to these markets. It is therefore necessary to develop reliable diagnosis tools adapted to these two applications' requirements. More particularly, online and real time tools for diagnosis will permit an early faults diagnosis and therefore an increase of the system reliability and performance. Most of the existing fault diagnos...

  8. Barcoding reveals complex clonal dynamics of de novo transformed human mammary cells.

    Science.gov (United States)

    Nguyen, Long V; Pellacani, Davide; Lefort, Sylvain; Kannan, Nagarajan; Osako, Tomo; Makarem, Maisam; Cox, Claire L; Kennedy, William; Beer, Philip; Carles, Annaick; Moksa, Michelle; Bilenky, Misha; Balani, Sneha; Babovic, Sonja; Sun, Ivan; Rosin, Miriam; Aparicio, Samuel; Hirst, Martin; Eaves, Connie J

    2015-12-10

    Most human breast cancers have diversified genomically and biologically by the time they become clinically evident. Early events involved in their genesis and the cellular context in which these events occur have thus been difficult to characterize. Here we present the first formal evidence of the shared and independent ability of basal cells and luminal progenitors, isolated from normal human mammary tissue and transduced with a single oncogene (KRAS(G12D)), to produce serially transplantable, polyclonal, invasive ductal carcinomas within 8 weeks of being introduced either subrenally or subcutaneously into immunodeficient mice. DNA barcoding of the initial cells revealed a dramatic change in the numbers and sizes of clones generated from them within 2 weeks, and the first appearance of many 'new' clones in tumours passaged into secondary recipients. Both primary and secondary tumours were phenotypically heterogeneous and primary tumours were categorized transcriptionally as 'normal-like'. This system challenges previous concepts that carcinogenesis in normal human epithelia is necessarily a slow process requiring the acquisition of multiple driver mutations. It also presents the first description of initial events that accompany the genesis and evolution of malignant human mammary cell populations, thereby contributing new understanding of the rapidity with which heterogeneity in their properties can develop. PMID:26633636

  9. Mature cystic teratoma with malignant transformation of teratomatous urothelial cells: Rare case presentation

    Directory of Open Access Journals (Sweden)

    Senjuti Dasgupta

    2015-01-01

    Full Text Available The occurrence of malignancies in somatic elements of mature cystic teratoma of ovary is rare. The malignancies that may be encountered in dermoid cyst include squamous cell carcinoma, adenocarcinoma, adenosquamous carcinoma, melanoma, sarcoma, carcinoid, and germ cell neoplasms. The development of transitional cell carcinoma (TCC in dermoid cyst is extremely rare with only four such cases having been reported in literature so far. Here we report the fifth case of such an occurrence in a 50-year-old postmenopausal multiparous female patient. She presented with pain and gradual swelling of abdomen for 1 month. Abdominal computed tomography revealed a solid space occupying lesion with few cystic components at right pelvis, raising the possibility of an ovarian neoplasm. The level of CA-125 was slightly raised (56∙45 U/ml. Total abdominal hysterectomy and bilateral salpingo-oopherectomy was performed. Microscopic examination showed cyst wall lined by stratified squamous epithelium. Beneath the cyst wall, a tumor mass was present, histological features of which resembled that of high-grade TCC (stage pT1aNXMX. On immunohistochemical analysis, the tumor was found to be positive for CK7 and CK20 and negative for WT-1. These results were consistent with a diagnosis of TCC arising in urothelium of mature cystic teratoma. Reporting of such extremely rare cases is important for the assessment of prognostic factors and treatment protocols.

  10. Involvement of p53 Mutation and Mismatch Repair Proteins Dysregulation in NNK-Induced Malignant Transformation of Human Bronchial Epithelial Cells

    Directory of Open Access Journals (Sweden)

    Ying Shen

    2014-01-01

    Full Text Available Genome integrity is essential for normal cellular functions and cell survival. Its instability can cause genetic aberrations and is considered as a hallmark of most cancers. To investigate the carcinogenesis process induced by tobacco-specific carcinogen NNK, we studied the dynamic changes of two important protectors of genome integrity, p53 and MMR system, in malignant transformation of human bronchial epithelial cells after NNK exposure. Our results showed that the expression of MLH1, one of the important MMR proteins, was decreased early and maintained the downregulation during the transformation in a histone modification involved and DNA methylation-independent manner. Another MMR protein PMS2 also displayed a declined expression while being in a later stage of transformation. Moreover, we conducted p53 mutation analysis and revealed a mutation at codon 273 which led to the replacement of arginine by histidine. With the mutation, DNA damage-induced activation of p53 was significantly impaired. We further reintroduced the wild-type p53 into the transformed cells, and the malignant proliferation can be abrogated by inducing cell cycle arrest and apoptosis. These findings indicate that p53 and MMR system play an important role in the initiation and progression of NNK-induced transformation, and p53 could be a potential therapeutic target for tobacco-related cancers.

  11. Morphological transformation and effect on gap junction intercellular communication in Syrian hamster embryo cells as screening tests for carcinogens devoid of mutagenic activity.

    Science.gov (United States)

    Rivedal, E; Mikalsen, S O; Sanner, T

    2000-04-01

    A large fraction of chemicals observed to cause cancer in experimental animals is devoid of mutagenic activity. It is therefore of importance to develop methods that can be used to detect and study environmental carcinogenic agents that do not interact directly with DNA. Previous studies have indicated that induction of in vitro cell transformation and inhibition of gap junction intercellular communication are endpoints that could be useful for the detection of non-genotoxic carcinogens. In the present work, 13 compounds [chlordane, Arochlor 1260, di(2-ethylhexyl)phthalate, 1,1,1-trichloro-2, 2-bis(4-chlorophenyl)ethane, limonene, sodium fluoride, ethionine, o-anisidine, benzoyl peroxide, o-vanadate, phenobarbital, 12-O-tetradecanoylphorbol 13-acetate and clofibrate] have been tested for their ability to induce morphological transformation and affect intercellular communication in Syrian hamster embryo cells. The substances were selected on the basis of being proven or suspected non-genotoxic carcinogens, and thus difficult to detect in short-term tests. The data show that nine of the 13 compounds induced morphological transformation, and seven of the 13 inhibited intercellular communication in hamster embryo cells. Taken together, 12 of the 13 substances either induced transformation or caused inhibition of communication. The data suggest that the combined use of morphological transformation and gap junction intercellular communication in Syrian hamster embryo cells may be beneficial when screening for non-genotoxic carcinogens. PMID:10793297

  12. Long-term low-dose α-particle enhanced the potential of malignant transformation in human bronchial epithelial cells through MAPK/Akt pathway

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Weili; Xiao, Linlin; Dong, Chen; He, Mingyuan; Pan, Yan; Xie, Yuexia; Tu, Wenzhi; Fu, Jiamei; Shao, Chunlin, E-mail: clshao@shmu.edu.cn

    2014-05-09

    Highlights: • Multi-exposures of 25 mGy α-ray enhanced cell proliferation, adhesion, and invasion. • MAPK/Akt but not JNK/P66 was positively correlated with cell invasive phenotypes. • LDR of α-irradiation triggers cell malignant transformation through MAPK/Akt. - Abstract: Since the wide usage of ionizing radiation, the cancer risk of low dose radiation (LDR) (<0.1 Gy) has become attractive for a long time. However, most results are derived from epidemiologic studies on atomic-bomb survivors and nuclear accidents surrounding population, and the molecular mechanism of this risk is elusive. To explore the potential of a long-term LDR-induced malignant transformation, human bronchial epithelial cells Beas-2B were fractionally irradiated with 0.025 Gy α-particles for 8 times in total and then further cultured for 1–2 months. It was found that the cell proliferation, the abilities of adhesion and invasion, and the protein expressions of p-ERK, p-Akt, especially p-P38 were not only increased in the multiply-irradiated cells but also in their offspring 1–2 months after the final exposure, indicating high potentiality of cell malignant transformation. On opposite, the expressions of p-JNK and p-P66 were diminished in the subcultures of irradiated cells and thus may play a role of negative regulation in canceration. When the cells were transferred with p38 siRNA, the LDR-induced enhancements of cell adhesion and invasion were significantly reduced. These findings suggest that long-term LDR of α-particles could enhance the potential of malignant transformation incidence in human bronchial epithelial cells through MAPK/Akt pathway.

  13. A role for transcriptional repression of p21CIP1 by c-Myc in overcoming transforming growth factor β-induced cell-cycle arrest

    OpenAIRE

    Claassen, Gisela F.; Hann, Stephen R.

    2000-01-01

    c-Myc plays a vital role in cell-cycle progression. Deregulated expression of c-Myc can overcome cell-cycle arrest in order to promote cellular proliferation. Transforming growth factor β (TGFβ) treatment of immortalized human keratinocyte cells inhibits cell-cycle progression and is characterized by down-regulation of c-Myc followed by up-regulation of p21CIP1. A direct role of c-Myc in this pathway was demonstrated by the observation that ectopic expression of c-Myc overcame the cell-cycle ...

  14. In vitro study of the influence of alpha particles irradiation on the pre-neoplastic transformation of rat trachea epithelial cells

    International Nuclear Information System (INIS)

    Intern contamination by actinide oxide inhalation is potentially one health hazard during the nuclear fuel fabrication process. The aerosol particles can induce pulmonary lesions, such as epithelial cancers in particular. Their toxicity is mainly due to radiotoxicity of α irradiation. The aim of this work was to contribute, by an in vitro model, to the study of the apparition of pre-neoplastic states on epithelial cells after high LET irradiation. Primary cultures of rat tracheal epithelial cells were used. Two rat strain cells, SD TR for Sprague Dawley rats and WF TR for Wistar Furth I Fischer F344 rats, were compared after exposure to a dose range from 0 to 5 Gy. Reproductive cell death, i.e. senescent death, seems to be the main lethal way induced by α and γ irradiations. The nuclear volume of WF TR cells is higher than that of SD TR ones, explaining the higher α radiation-induced lethality of these cells. These WF TR cells are also much sensitive to dose rate and α particles energy. In the same manner, pre-neoplastic transformation rate of the cells seems to depend on the physical parameters of irradiation. But, it mainly varies as a function of cell radiosensitivity, that means cell death. In fact, the transformation rate of sensitive WF TR cells is lower than that of SD TR ones. In term of transformation for SD TR cells, dose-effect relationship fits to a linear and infra linear function after α irradiation, whereas the curve fits to linear and quadratic function after γ irradiation. The Relative Biological Efficiency (RBE) of α particles for lethality and pre-neoplastic transformation were determined for several levels of dose. A constant value of about 3 was found for RBE of lethality whatever the α dose. By contrast, the RBE of transformation has a value of about 10 up to 0.5 Gy and gradually decreases at higher doses to reach a value of 1 at 5 Gy. Similar shapes of dose-effect relationship can be observed for malignant lung tumour induction after

  15. High-density growth arrest in Ras-transformed cells: low Cdk kinase activities in spite of absence of p27Kip Cdk-complexes

    DEFF Research Database (Denmark)

    Groth, Anja; Willumsen, Berthe Marie

    2005-01-01

    The ras oncogene transforms immortalized, contact-inhibited non-malignant murine fibroblasts into cells that are focus forming, exhibit increased saturation density, and are malignant in suitable hosts. Here, we examined changes in cell cycle control complexes as normal and Ras-transformed cells...... ceased to grow exponentially, to reveal the molecular basis for Ras-dependent focus formation. As normal cells entered density-dependent arrest, cyclin D1 decreased while cyclin D2 was induced and replaced D1 in Cdk4 complexes. Concomitantly, p27Kip1 levels rose and the inhibitor accumulated in both Cdk4......-like state with low Cdk4 and Cdk2 activity. Surprisingly, this delayed arrest was molecularly distinct from contact inhibition of normal cells, as it occurred in the absence of p27Kip1 induction and cyclin D1 levels remained high. This demonstrates that although oncogenic Ras efficiently disabled the normal...

  16. Regulation of follicular B cell differentiation by the related E26 transformation-specific transcription factors PU.1, Spi-B, and Spi-C.

    Science.gov (United States)

    DeKoter, Rodney P; Geadah, Marc; Khoosal, Sonam; Xu, Li S; Thillainadesan, Gobi; Torchia, Joseph; Chin, Shu Shien; Garrett-Sinha, Lee Ann

    2010-12-15

    Splenic B-2 cells can be divided into two major subsets: follicular (FO) and marginal zone (MZ) B cells. FO and MZ B cells are generated from immature transitional B cells. Few transcription factors have been identified that regulate FO B cell differentiation. The highly related proteins PU.1, Spi-B, and Spi-C are transcription factors of the E26-transformation-specific family and are important for B cell differentiation and function. To determine whether these proteins play a role in the differentiation of FO B cells, we performed a detailed analysis of splenic B cells in mice with inactivating mutations in the genes encoding PU.1 (Sfpi1) or Spi-B (Spib). Sfpi1(+/-) Spib(-/-) (PUB) mice had a 9-fold reduction in the frequency of CD23(+) FO B cells compared with that of wild-type mice. In contrast, PUB mice had a 2-fold increase in the frequency of MZ B cells that was confirmed by immunofluorescence staining. Expression of Spi-C in Eμ-Spi-C transgenic PUB mice partially rescued frequencies of CD23(+) B cells. Gene expression analysis, in vitro reporter assays, and chromatin immunoprecipitation experiments showed that transcription of the Fcer2a gene encoding CD23 is activated by PU.1, Spi-B, and Spi-C. These results demonstrate that FO B cell differentiation is regulated by the E26-transformation-specific transcription factors PU.1, Spi-B, and Spi-C.

  17. Role of phosphorylated histone H3 serine 10 in DEN-induced deregulation of Pol III genes and cell proliferation and transformation

    OpenAIRE

    Zhong, Qian; Shi, Ganggang; Zhang, Qingsong; Zhang, Yanmei; Levy, Daniel; Zhong, Shuping

    2013-01-01

    The products of Pol III genes (RNA polymerase III-dependent genes), such as tRNAs and 5S rRNA, are elevated in both transformed and tumor cells suggesting that they play a crucial role in tumorigenesis. An increase in Brf1 (TFIIIB-related factor 1), a subunit of TFIIIB, augments Pol III gene transcription and is sufficient for cell transformation and tumor formation. We have demonstrated that enhancement of Brf1 and Pol III gene expression is associated with the occurrences of hepatocellular ...

  18. Solvent and Intermediate Phase as Boosters for the Perovskite Transformation and Solar Cell Performance

    OpenAIRE

    Jinhyun Kim; Taehyun Hwang; Sangheon Lee; Byungho Lee; Jaewon Kim; Gil Su Jang; Seunghoon Nam; Byungwoo Park

    2016-01-01

    High power conversion efficiency and device stabilization are two major challenges for CH3NH3PbI3 (MAPbI3) perovskite solar cells to be commercialized. Herein, we demonstrate a diffusion-engineered perovskite synthesis method using MAI/ethanol dipping, and compared it to the conventional synthesis method from MAI/iso-propanol. Diffusion of MAI/C2H5OH into the PbCl2 film was observed to be more favorable than that of MAI/C3H7OH. Facile perovskite conversion from ethanol and highly-crystalline ...

  19. Transforming human blood stem and progenitor cells: A new way forward in leukemia modeling

    OpenAIRE

    Mulloy, James C.; Wunderlich, Mark; Zheng, Yi; Wei, Junping

    2008-01-01

    MLL-AF9 (MA9) is a leukemia fusion gene formed upon translocation of the AF9 gene on chromosome 9 and the MLL gene on chromosome 11. MA9 is commonly found in acute myeloid leukemia (AML) and occasionally in acute lymphoid leukemia and is associated with intermediate to poor outcome. The specific signaling pathways downstream of MA9 are still poorly understood. We have recently described a model system whereby we expressed the MA9 fusion gene in human CD34+ Umbilical Cord Blood (UCB) cells and...

  20. Using a Quasipotential Transformation for Modeling Diffusion Media inPolymer-Electrolyte Fuel Cells

    Energy Technology Data Exchange (ETDEWEB)

    Weber, Adam Z.; Newman, John

    2008-08-29

    In this paper, a quasipotential approach along with conformal mapping is used to model the diffusion media of a polymer-electrolyte fuel cell. This method provides a series solution that is grid independent and only requires integration along a single boundary to solve the problem. The approach accounts for nonisothermal phenomena, two-phase flow, correct placement of the electronic potential boundary condition, and multilayer media. The method is applied to a cathode diffusion medium to explore the interplay between water and thermal management and performance, the impact of the rib-to-channel ratio, and the existence of diffusion under the rib and flooding phenomena.

  1. Targeting Epstein-Barr virus–transformed B lymphoblastoid cells using antibodies with T-cell receptor–like specificities

    Science.gov (United States)

    Lai, Junyun; Tan, Wei Jian; Too, Chien Tei; Choo, Joanna Ai Ling; Wong, Lan Hiong; Mustafa, Fatimah Bte; Srinivasan, Nalini; Lim, Angeline Pei Chiew; Zhong, Youjia; Gascoigne, Nicholas R. J.; Hanson, Brendon J.; Chan, Soh Ha; Chen, Jianzhu

    2016-01-01

    Epstein-Barr virus (EBV) is an oncovirus associated with several human malignancies including posttransplant lymphoproliferative disease in immunosuppressed patients. We show here that anti-EBV T-cell receptor–like monoclonal antibodies (TCR-like mAbs) E1, L1, and L2 bound to their respective HLA-A*0201-restricted EBV peptides EBNA1562-570, LMP1125-133, and LMP2A426-434 with high affinities and specificities. These mAbs recognized endogenously presented targets on EBV B lymphoblastoid cell lines (BLCLs), but not peripheral blood mononuclear cells, from which they were derived. Furthermore, these mAbs displayed similar binding activities on several BLCLs, despite inherent heterogeneity between different donor samples. A single weekly administration of the naked mAbs reduced splenomegaly, liver tumor spots, and tumor burden in BLCL-engrafted immunodeficient NOD-SCID/Il2rg−/− mice. In particular, mice that were treated with the E1 mAb displayed a delayed weight loss and significantly prolonged survival. In vitro, these TCR-like mAbs induced early apoptosis of BLCLs, thereby enhancing their Fc-dependent phagocytic uptake by macrophages. These data provide evidence for TCR-like mAbs as potential therapeutic modalities to target EBV-associated diseases. PMID:27338099

  2. A reliable protocol for the stable transformation of non-embryogenic cells cultures of grapevine (Vitis vinifera L. and Taxus x media

    Directory of Open Access Journals (Sweden)

    Ascensión Martínez-Márquez

    2015-06-01

    Full Text Available One of the major intent of metabolic engineering in cell culture systems is to increase yields of secondary metabolites. Efficient transformation methods are a priority to successfully apply metabolic engineering to cell cultures of plants that produce bioactive or therapeutic compounds, such as Vitis vinifera and Taxus x media. The aim of this study was to establish a reliable method to transform non-embryogenic cell cultures of these species. The V. vinifera cv. Gamay/cv. Monastrell cell lines and Taxus x media were used for Agrobacterium-mediated transformation using the Gateway-compatible Agrobacterium sp. binary vector system for fast reliable DNA cloning. The Taxus x media and Vitis cell lines were maintained in culture for more than 4 and 15 months, respectively, with no loss of reporter gene expression or antibiotic resistance. The introduced genes had no discernible effect on cell growth, or led to extracellular accumulation of phytoalexin trans-Resveratrol (t-R in response to elicitation with methylated cyclodextrins (MBCD and methyl jasmonate (MeJA in the grapevine transgenic cell lines compared to the parental control. The method described herein provides an excellent tool to exploit exponentially growing genomic resources to enhance, optimize or diversify the production of bioactive compounds generated by grapevine and yew cell cultures, and offers a better understanding of many grapevine and yew biology areas.

  3. Expression and clinical significance of dendritic cell and transforming growth factor-beta 1 in cervical cancer

    Institute of Scientific and Technical Information of China (English)

    Zhao; Shan; Rong; Fengnian

    2006-01-01

    Objective:To explore the density and mature status of Dendritic cell(DC) in cervical cancer and correlation with the expression of transforming growth factor-beta 1(TGF-β1).Methods:Streptavidin-peroxidase(SP) immunohistochemistry methods were used to detect S-100 DC and the expression of TGF-β1 in 20 normal cervical tissues and 53 cervical cancer tissues without any sort of chemotherapy or radiation therapy prior to resection.Medical records were reviewed,clinicopathological variables were retrieved and used for analysis.Results:Two types of DC were observed under the microscope.The expression of DC in cervical cancer was significantly higher than that in normal tissues(23.34 cells/mm2 vs 29.91 cells/mm2,P<0.05),and significantly higher in early stage than that in advanced stage(P<0.05).The expression of TGF-β1 was significantly higher in cervical cancer than that in normal tissues (P<0.025).However,there was no correaction between TGF-β1 and lymph nodes metastasis.The index of DC in cervical cancer was negatively correlated to the expression of TGF-β1 in tumor cells (r=-0.8875,P=0.0001).Conclusion:Maturation of DC in cervical cancer is inhibited.The decreased number of DC and the higher expression of TGF-β1 are due to the failure of the immunity,these may play an important role in the development of the cervical cancer.

  4. 1,25-Dihydroxyvitamin D inhibits glutamine metabolism in Harvey-ras transformed MCF10A human breast epithelial cell.

    Science.gov (United States)

    Zhou, Xuanzhu; Zheng, Wei; Nagana Gowda, G A; Raftery, Daniel; Donkin, Shawn S; Bequette, Brian; Teegarden, Dorothy

    2016-10-01

    Breast cancer is the second most common cancer among women in the US. The active form of vitamin D, 1,25-dihydroxyvitamin D (1,25(OH)2D), is proposed to inhibit cellular processes and to prevent breast cancer. The current studies investigated the effect of 1,25(OH)2D on glutamine metabolism during cancer progression employing Harvey-ras oncogene transformed MCF10A human breast epithelial cells (MCF10A-ras). Treatment with 1,25(OH)2D significantly reduced intracellular glutamine and glutamate levels measured by nuclear magnetic resonance (NMR) by 23±2% each. Further, 1,25(OH)2D treatment reduced glutamine and glutamate flux, determined by [U-(13)C5] glutamine tracer kinetics, into the TCA cycle by 31±0.2% and 17±0.4%, respectively. The relative levels of mRNA and protein abundance of the major glutamine transporter, solute linked carrier family 1 member A5 (SLC1A5), was significantly decreased by 1,25(OH)2D treatment in both MCF10A-ras cells and MCF10A which overexpress ErbB2 (HER-2/neu). Consistent with these results, glutamine uptake was reduced by 1,25(OH)2D treatment and the impact was eliminated with the SLC1A5 inhibitor L-γ-Glutamyl-p-nitroanilide (GPNA). A consensus sequence to the vitamin D responsive element (VDRE) was identified in silico in the SLC1A5 gene promoter, and site-directed mutagenesis analyses with reporter gene studies demonstrate a functional negative VDRE in the promoter of the SLC1A5 gene. siRNA-SLC1A5 transfection in MCF10A-ras cells significantly reduced SLC1A5 mRNA expression as well as decreased viable cell number similar to 1,25(OH)2D treatment. SLC1A5 knockdown also induced an increase in apoptotic cells in MCF10A-ras cells. These results suggest 1,25(OH)2D alters glutamine metabolism in MCF10A-ras cells by inhibiting glutamine uptake and utilization, in part through down-regulation of SLC1A5 transcript abundance. Thus, 1,25(OH)2D down-regulation of the glutamine transporter, SLC1A5, may facilitate vitamin D prevention of breast

  5. The MicroRNA 424/503 Cluster Reduces CDC25A Expression during Cell Cycle Arrest Imposed by Transforming Growth Factor β in Mammary Epithelial Cells

    Science.gov (United States)

    Rodriguez-Barrueco, Ruth; de la Iglesia-Vicente, Janis; Olivan, Mireia; Castro, Veronica; Saucedo-Cuevas, Laura; Marshall, Netonia; Putcha, Preeti; Castillo-Martin, Mireia; Bardot, Evan; Ezhkova, Elena; Iavarone, Antonio; Cordon-Cardo, Carlos

    2014-01-01

    Recently, we demonstrated that the microRNA 424(322)/503 [miR-424(322)/503] cluster is transcriptionally controlled by transforming growth factor β (TGF-β) in the mammary epithelium. Induction of this microRNA cluster impacts mammary epithelium fate by regulating apoptosis and insulin-like growth factor 1 (IGF1) signaling. Here, we expanded our finding to demonstrate that miR-424(322)/503 is an integral component of the cell cycle arrest mediated by TGF-β. Mechanistically, we showed that after TGF-β exposure, increased levels of miR-424(322)/503 reduce the expression of the cell cycle regulator CDC25A. miR-424(322)/503-dependent posttranscriptional downregulation of CDC25A cooperates with previously described transcriptional repression of the CDC25A promoter and proteasome-mediated degradation to reduce the levels of CDC25A expression and to induce cell cycle arrest. We also provide evidence that the TGF-β/miR-424(322)/503 axis is part of the mechanism that regulates the proliferation of hormone receptor-positive (HR+) mammary epithelial cells in vivo. PMID:25266660

  6. Macrophages promote benzopyrene-induced tumor transformation of human bronchial epithelial cells by activation of NF-κB and STAT3 signaling in a bionic airway chip culture and in animal models

    OpenAIRE

    Li, Encheng; Xu, Zhiyun; Zhao, Hui; Sun, Zhao; Wang, Lei; Guo, Zhe; Zhao, Yang; GAO, ZHANCHENG; Wang, Qi

    2015-01-01

    We investigated the role of macrophages in promoting benzopyrene (BaP)-induced malignant transformation of human bronchial epithelial cells using a BaP-induced tumor transformation model with a bionic airway chip in vitro and in animal models. The bionic airway chip culture data showed that macrophages promoted BaP-induced malignant transformation of human bronchial epithelial cells, which was mediated by nuclear factor (NF)-κB and STAT3 pathways to induce cell proliferation, colony formation...

  7. Human umbilical cord Wharton's jelly mesenchymal stem cells do not transform to tumor-associated fibroblasts in the presence of breast and ovarian cancer cells unlike bone marrow mesenchymal stem cells.

    Science.gov (United States)

    Subramanian, Arjunan; Shu-Uin, Gan; Kae-Siang, Ngo; Gauthaman, Kalamegam; Biswas, Arijit; Choolani, Mahesh; Bongso, Ariff; Chui-Yee, Fong

    2012-06-01

    Human bone marrow mesenchymal stem cells (hBMMSCs) were shown to transform into tumor-associated fibroblasts (TAFs) when in the vicinity of breast cancer tumors and played an important role in tumor enhancement and metastasis. In early human development MSCs migrating from the yolk sac and aorta-gonad-mesonephros (AGM) via the umbilical cord to the placenta and back to the fetal bone marrow were shown to get trapped in the gelatinous Wharton's jelly of the umbilical cord. The common origin of the Wharton's jelly MSCs and the finally homed hBMMSCs prompted us to evaluate whether hWJSCs are also involved in TAF transformation. hWJSCs and hBMMSCs were grown in the presence of breast and ovarian cancer cell conditioned medium (MDA-TCM, TOV-TCM) for 30 days. No changes were observed in the hWJSCs but the hBMMSCs transformed from short to thin long fibroblasts, their proliferation rates increased and CD marker expression decreased. The transformed hBMMSCs showed positive staining for the tumor-associated markers FSP, VEGF, EGF, and Tn-C. Real-time PCR and multiplex luminex bead analysis showed upregulation of TAF-related genes (FSP, FAP, Tn-C, Tsp-1, EGF, bFGF, IL-6, α-SMA, VEGF, and TGF-β) for hBMMSCs with low expression for hWJSCs. The luciferase assay showed that hWJSCs previously exposed to MDA-TCM or TOV-TCM had no stimulatory growth effect on luciferase-tagged MDA or TOV cells unlike hBMMSCs. The results confirmed that hWJSCs do not transform to the TAF phenotype and may therefore not be associated with enhanced growth of solid tumors making them a safe MSC for cell based therapies. PMID:22234854

  8. Alterations in the antigen processing-presenting machinery of transformed plasma cells are associated with reduced recognition by CD8+ T cells and characterize the progression of MGUS to multiple myeloma

    OpenAIRE

    Racanelli, Vito; Leone, Patrizia; Frassanito, Maria Antonia; Brunetti, Claudia; Perosa, Federico; Ferrone, Soldano; Dammacco, Franco

    2010-01-01

    We hypothesized that progression of monoclonal gammopathy of undetermined significance (MGUS) to multiple myeloma (MM) reflects the escape of transformed plasma cells from T-cell recognition because of impaired antigen processing-presenting machinery (APM). We studied plasma cells and CD8+ T cells from bone marrow of 20 MGUS patients, 20 MM patients, and 10 control patients. Immunofluorescence and flow cytometry revealed significantly different patterns of APM component expression in plasma c...

  9. Berberine induces mitochondrial apoptosis of EBV-transformedcells through p53-mediated regulation of XAF1 and GADD45α.

    Science.gov (United States)

    Park, Ga Bin; Park, Sang Hyun; Kim, Daejin; Kim, Yeong Seok; Yoon, Sung Ho; Hur, Dae Young

    2016-07-01

    Berberine exhibits antiproliferative or cytotoxic effects against various cancers. ROS and wild-type p53 play a critical role in berberine-induced cytotoxic effects. In this study, we investigated the correlation between XAF1 and functional p53 in EBV-transformedcells or cancerous B cells after treatment with berberine. Berberine decreased cell viability and induced apoptosis through a mitochondria-dependent pathway in EBV-transformedcells and cancerous B cells, but not in normal peripheral blood mononuclear cells. Activated p53 and its downstream targets XAF1 and GADD45α interacted with PUMA, Bax, and Bim in mitochondria after treatment with berberine. Blocking phosphorylation of p38/JNK MAPK and treatment with PFT-α, a selective p53 inhibitor, effectively prevented apoptosis and the upregulation of phosphorylated p53, XAF1, and GADD45α. NAC, a ROS scavenger, also suppressed berberine-induced mitochondria disruption and the whole apoptotic process via restoration of p53-related proteins and proapoptotic Bcl-2 family proteins. Taken together, our results suggest that ROS generation might be a predisposing event in berberine-induced mitochondrial apoptosis in EBV-transformedcells through the upregulation of XAF1 and GADD45α expression by MAPK and functional p53. PMID:27121748

  10. Identification of a transformer homolog in the acorn worm, Saccoglossus kowalevskii, and analysis of its activity in insect cells.

    Science.gov (United States)

    Suzuki, Masataka G; Tochigi, Mayuko; Sakaguchi, Honami; Aoki, Fugaku; Miyamoto, Norio

    2015-06-01

    The transformer (tra) gene is an intermediate component of the sex determination hierarchy in many insect species. The homolog of tra is also found in two branchiopod crustacean species but is not known outside arthropods. We have isolated a tra homolog in the acorn worm, Saccoglossus kowalevskii, which is a hemichordate belonging to the deuterostome superphylum. The full-length complementary DNA (cDNA) of the S. kowalevskii tra homolog (Sktra) has a 3786-bp open reading frame that encodes a 1261-amino acid sequence including a TRA-CAM domain and an arginine/serine (RS)-rich domain, both of which are characteristic of TRA orthologs. Reverse transcription PCR (RT-PCR) analyses demonstrated that Sktra showed no differences in expression patterns between testes and ovaries, but its expression level was approximately 7.5-fold higher in the testes than in the ovaries. TRA, together with the protein product of the transformer-2 (tra-2) gene, assembles on doublesex (dsx) pre-messenger RNA (mRNA) via the cis-regulatory element, enhancing female-specific splicing of dsx in Drosophila. To understand functional conservation of the SkTRA protein as a dsx-splicing activator, we investigated whether SkTRA is capable of inducing female-specific splicing of the Drosophila dsx. Ectopic expression of Sktra cDNA in insect cultured cells did not induce the female-specific splicing of dsx. On the other hand, forced expression of Sktra-2 (a tra-2 homolog of S. kowalevskii) was able to induce the female-specific dsx splicing. These results demonstrate that the function as a dsx-splicing activator is not conserved in SkTRA even though SkTRA-2 is capable of functionally replacing the Drosophila TRA-2. We have also found a tra homolog in an echinoderm genome. This study provides the first evidence that that tra is conserved not only in arthropods but also in basal species of deuterostoms.

  11. Antigen and transforming growth factor beta receptors contribute to long term functional and phenotypic heterogeneity of memory CD8 T cells.

    Directory of Open Access Journals (Sweden)

    Yinghong eHu

    2013-08-01

    Full Text Available Pathogen-specific CD8 T cells provide a mechanism for selectively eliminating host cells that are harboring intracellular pathogens. The pathogens are killed when lytic molecules are injected into the cytoplasm of the infected cells and begin an apoptotic cascade. Activated CD8 T cells also release large quantities of proinflammatory cytokines that stimulate other immune cells in the local vicinity. As the alveoli are extraordinarily sensitive to cytokine induced damage, multiple layers of immune regulation limit the activities of immune cells that enter the lungs. These mechanisms include receptor-mediated signaling pathways in CD8 T cells that respond to peptide antigens and transforming growth factor-beta. Both pathways influence the functional and phenotypic properties of long-lived CD8 T cells populations in peripheral and lymphoid tissues.

  12. Solvent and Intermediate Phase as Boosters for the Perovskite Transformation and Solar Cell Performance

    Science.gov (United States)

    Kim, Jinhyun; Hwang, Taehyun; Lee, Sangheon; Lee, Byungho; Kim, Jaewon; Jang, Gil Su; Nam, Seunghoon; Park, Byungwoo

    2016-05-01

    High power conversion efficiency and device stabilization are two major challenges for CH3NH3PbI3 (MAPbI3) perovskite solar cells to be commercialized. Herein, we demonstrate a diffusion-engineered perovskite synthesis method using MAI/ethanol dipping, and compared it to the conventional synthesis method from MAI/iso-propanol. Diffusion of MAI/C2H5OH into the PbCl2 film was observed to be more favorable than that of MAI/C3H7OH. Facile perovskite conversion from ethanol and highly-crystalline MAPbI3 with minimized impurities boosted the efficiency from 5.86% to 9.51%. Additionally, we further identified the intermediates and thereby the reaction mechanisms of PbCl2 converting into MAPbI3. Through straightforward engineering to enhance the surface morphology as well as the crystallinity of the perovskite with even faster conversion, an initial power conversion efficiency of 11.23% was obtained, in addition to superior stability after 30 days under an ambient condition.

  13. Comparative two-dimensional gel analysis and microsequencing identifies gelsolin as one of the most prominent downregulated markers of transformed human fibroblast and epithelial cells

    DEFF Research Database (Denmark)

    Vandekerckhove, J; Bauw, G; Vancompernolle, K;

    1990-01-01

    A systematic comparison of the protein synthesis patterns of cultured normal and transformed human fibroblasts and epithelial cells, using two-dimensional gel protein analysis combined with computerized imaging and data acquisition, identified a 90-kD protein (SSP 5714) as one of the most striking...... downregulated markers typical of the transformed state. Using the information stored in the comprehensive human cellular protein database, we found this protein strongly expressed in several fetal tissues and one of them, epidermis, served as a source for preparative two-dimensional gel electrophoresis. Partial...... coelectrophoresis with purified human gelsolin. These results suggest that an important regulatory protein of the microfilament system may play a role in defining the phenotype of transformed human fibroblast and epithelial cells in culture. Udgivelsesdato: 1990-Jul...

  14. Human Induced Pluripotent Stem Cell-Derived Cardiac Progenitor Cells in Phenotypic Screening: A Transforming Growth Factor-β Type 1 Receptor Kinase Inhibitor Induces Efficient Cardiac Differentiation.

    Science.gov (United States)

    Drowley, Lauren; Koonce, Chad; Peel, Samantha; Jonebring, Anna; Plowright, Alleyn T; Kattman, Steven J; Andersson, Henrik; Anson, Blake; Swanson, Bradley J; Wang, Qing-Dong; Brolen, Gabriella

    2016-02-01

    Several progenitor cell populations have been reported to exist in hearts that play a role in cardiac turnover and/or repair. Despite the presence of cardiac stem and progenitor cells within the myocardium, functional repair of the heart after injury is inadequate. Identification of the signaling pathways involved in the expansion and differentiation of cardiac progenitor cells (CPCs) will broaden insight into the fundamental mechanisms playing a role in cardiac homeostasis and disease and might provide strategies for in vivo regenerative therapies. To understand and exploit cardiac ontogeny for drug discovery efforts, we developed an in vitro human induced pluripotent stem cell-derived CPC model system using a highly enriched population of KDR(pos)/CKIT(neg)/NKX2.5(pos) CPCs. Using this model system, these CPCs were capable of generating highly enriched cultures of cardiomyocytes under directed differentiation conditions. In order to facilitate the identification of pathways and targets involved in proliferation and differentiation of resident CPCs, we developed phenotypic screening assays. Screening paradigms for therapeutic applications require a robust, scalable, and consistent methodology. In the present study, we have demonstrated the suitability of these cells for medium to high-throughput screens to assess both proliferation and multilineage differentiation. Using this CPC model system and a small directed compound set, we identified activin-like kinase 5 (transforming growth factor-β type 1 receptor kinase) inhibitors as novel and potent inducers of human CPC differentiation to cardiomyocytes. Significance: Cardiac disease is a leading cause of morbidity and mortality, with no treatment available that can result in functional repair. This study demonstrates how differentiation of induced pluripotent stem cells can be used to identify and isolate cell populations of interest that can translate to the adult human heart. Two separate examples of phenotypic

  15. Lysyl oxidase contributes to mechanotransduction-mediated regulation of transforming growth factor-β signaling in breast cancer cells.

    Science.gov (United States)

    Taylor, Molly A; Amin, Jay D; Kirschmann, Dawn A; Schiemann, William P

    2011-05-01

    Transforming growth factor-β (TGF-β) regulates all stages of mammary gland development, including the maintenance of tissue homeostasis and the suppression of tumorigenesis in mammary epithelial cells (MECs). Interestingly, mammary tumorigenesis converts TGF-β from a tumor suppressor to a tumor promoter through molecular mechanisms that remain incompletely understood. Changes in integrin signaling and tissue compliance promote the acquisition of malignant phenotypes in MECs in part through the activity of lysyl oxidase (LOX), which regulates desmoplastic reactions and metastasis. TGF-β also regulates the activities of tumor reactive stroma and MEC metastasis. We show here that TGF-β1 stimulated the synthesis and secretion of LOX from normal and malignant MECs in vitro and in mammary tumors produced in mice. The ability of TGF-β1 to activate Smad2/3 was unaffected by LOX inactivation in normal MECs, whereas the stimulation of p38 MAPK by TGF-β1 was blunted by inhibiting LOX activity in malignant MECs or by inducing the degradation of hydrogen peroxide in both cell types. Inactivating LOX activity impaired TGF-β1-mediated epithelial-mesenchymal transition and invasion in breast cancer cells. We further show that increasing extracellular matrix rigidity by the addition of type I collagen to three-dimensional organotypic cultures promoted the proliferation of malignant MECs, a cellular reaction that was abrogated by inhibiting the activities of TGF-β1 or LOX, and by degrading hydrogen peroxide. Our findings identify LOX as a potential mediator that couples mechanotransduction to oncogenic signaling by TGF-β1 and suggest that measures capable of inactivating LOX function may prove effective in diminishing breast cancer progression stimulated by TGF-β1.

  16. Lysyl Oxidase Contributes to Mechanotransduction-Mediated Regulation of Transforming Growth Factor-β Signaling in Breast Cancer Cells

    Directory of Open Access Journals (Sweden)

    Molly A. Taylor

    2011-05-01

    Full Text Available Transforming growth factor-β (TGF-β regulates all stages of mammary gland development, including the maintenance of tissue homeostasis and the suppression of tumorigenesis in mammary epithelial cells (MECs. Interestingly, mammary tumorigenesis converts TGF-β from a tumor suppressor to a tumor promoter through molecular mechanisms that remain incompletely understood. Changes in integrin signaling and tissue compliance promote the acquisition of malignant phenotypes in MECs in part through the activity of lysyl oxidase (LOX, which regulates desmoplastic reactions and metastasis. TGF-β also regulates the activities of tumor reactive stroma and MEC metastasis. We show here that TGF-β1 stimulated the synthesis and secretion of LOX from normal and malignant MECs in vitro and in mammary tumors produced in mice. The ability of TGF-β1 to activate Smad2/3 was unaffected by LOX inactivation in normal MECs, whereas the stimulation of p38 MAPK by TGF-β1 was blunted by inhibiting LOX activity in malignant MECs or by inducing the degradation of hydrogen peroxide in both cell types. Inactivating LOX activity impaired TGF-β1-mediated epithelial-mesenchymal transition and invasion in breast cancer cells. We further show that increasing extracellular matrix rigidity by the addition of type I collagen to three-dimensional organotypic cultures promoted the proliferation of malignant MECs, a cellular reaction that was abrogated by inhibiting the activities of TGF-β1 or LOX, and by degrading hydrogen peroxide. Our findings identify LOX as a potential mediator that couples mechanotransduction to oncogenic signaling by TGF-β1 and suggest that measures capable of inactivating LOX function may prove effective in diminishing breast cancer progression stimulated by TGF-β1.

  17. 5-Azacytidine treatment of HA-A melanoma cells induces Sp1 activity and concomitant transforming growth factor alpha expression.

    Science.gov (United States)

    Shin, T H; Paterson, A J; Grant, J H; Meluch, A A; Kudlow, J E

    1992-01-01

    Evidence indicates DNA methylation as a part of the regulatory machinery controlling mammalian gene expression. The human melanoma cell line HA-A expresses low levels of transforming growth factor alpha (TGF-alpha). TGF-alpha mRNA accumulated, however, in response to DNA demethylation induced by a nucleoside analog, 5-azacytidine (5-azaC). The importance of DNA methylation in the TGF-alpha promoter region was examined by a transient transfection assay with luciferase reporter plasmids containing a portion of the TGF-alpha promoter. 5-azaC treatment of HA-A cells before the transfection caused a significant increase in the luciferase activity. Since input plasmids were confirmed to remain unmethylated, DNA demethylation of the TGF-alpha promoter itself does not account for the observed increase in TGF-alpha mRNA. Using an electrophoretic mobility shift assay, enhanced formation of protein-TGF-alpha promoter complex was detected in response to 5-azaC treatment. This 5-azaC-induced complex was shown to contain the transcription factor Sp1 by the following criteria: the protein-DNA complex formed on the TGF-alpha promoter contained immunoreactive Sp1; the mobility of the complex in an electrophoretic mobility shift assay was similar to that formed by recombinant Sp1; and DNase I footprinting analysis demonstrated that the 5-azaC-induced complex produced a footprint on the TGF-alpha promoter identical to that of authentic Sp1. These observations suggest that 5-azaC induces TGF-alpha expression by augmenting the Sp1 activity. However, neither the Sp1 mRNA nor its protein was induced by 5-azaC. These results suggest that in HA-A cells, TGF-alpha expression is down-modulated by DNA methylation. In addition, this process may involve the specific regulation of Sp1 activity without altering the amount of the transcription factor. Images PMID:1380648

  18. Feedback regulations of miR-21 and MAPKs via Pdcd4 and Spry1 are involved in arsenite-induced cell malignant transformation.

    Directory of Open Access Journals (Sweden)

    Lu Shen

    Full Text Available OBJECTIVE: To establish the functions of miR-21 and the roles of two feedback regulation loops, miR-21-Spry1-ERK/NF-κB and miR-21-Pdcd4-JNK/c-Jun, in arsenite-transformed human embryo lung fibroblast (HELF cells. METHODS: For arsenite-transformed HELF cells, apoptosis, clonogenicity, and capacity for migration were determined by Hoechst staining, assessment of their capacity for anchorage-independent growth, and wound-healing, respectively, after blockage, with inhibitors or with siRNAs, of signal pathways for JNK/c-Jun or ERK/NF-κB. Decreases of miR-21 levels were determined with anti-miR-21, and the up-regulation of Pdcd4 and Spry1 was assessed in transfected cells; these cells were molecularly characterized by RT-PCR, qRT-PCR, Western blots, and immunofluorescence assays. RESULTS: MiR-21 was highly expressed in arsenite-transformed HELF cells and normal HELF cells acutely treated with arsenite, an effect that was concomitant with activation of JNK/c-Jun and ERK/NF-κB and down-regulation of Pdcd4 and Spry1 protein levels. However, there were no significant changes in mRNA levels for Pdcd4 and Spry1, which suggested that miR-21 regulates the expressions of Pdcd4 and Spry1 through translational repression. In arsenite-transformed HELF cells, blockages of JNK/c-Jun or ERK/NF-κB with inhibitors or with siRNAs prevented the increases of miR-21and the decreases of the protein levels but not the mRNA levels of Pdcd4 and Spry1. Down-regulation of miR-21 and up-regulations of Pdcd44 or Spry1 blocked the arsenite-induced activations of JNK/c-Jun or ERK/NF-κB, indicating that knockdown of miR-21 inhibits feedback of ERK activation and JNK activation via increases of Pdcd4 and Spry1 protein levels, respectively. Moreover, in arsenite-transformed HELF cells, inhibition of miR-21 promoted cell apoptosis, inhibited clonogenicity, and reduced migration. CONCLUSION: The results indicate that miR-21 is both a target and a regulator of ERK/NF-κB and JNK

  19. Spontaneous increase of transforming growth factor beta production by bronchoalveolar mononuclear cells of patients with systemic autoimmune diseases affecting the lung.

    OpenAIRE

    Deguchi, Y.

    1992-01-01

    The spontaneous increase in the transcription of the transforming growth factor beta (TGF beta) gene in bronchoalveolar mononuclear cells of patients with autoimmune diseases affecting the lung has been shown by northern blot assay and a nuclear run on transcription assay. Transcription of the TGF beta gene in bronchoalveolar mononuclear cells of patients with autoimmune diseases affecting the lung was increased 10 times compared with normal healthy subjects or patients with bronchial asthma ...

  20. Human transforming growth factor type α coding sequence is not a directed-acting oncogene when overexpressed in NIH 3T3 cells

    International Nuclear Information System (INIS)

    A peptide secreted by some tumor cells in vitro imparts anchorage-independent growth to normal rat kidney (NRK) cells and has been termed transforming growth factor type α (TGF-α). To directly investigate the transforming properties of this factor, the human sequence coding for TGF-α was placed under the control of either a metallothionein promoter or a retroviral long terminal repeat. These constructs failed to induce morphological transformation upon transfection of NIH 3T3 cells, whereas viral oncogenes encoding a truncated form of its cognate receptor, the EGF receptor, or another growth factor, sis/platelet-derived growth factor 2, efficiently induced transformed foci. Binding assays were done using [125I]-EGF. When NIH 3T3 clonal sublines were selected by transfection of TGF-α expression vectors in the presence of a dominant selectable market, they were shown to secrete large amounts of TGF-α into the medium, to have downregulated EGF receptors, and to be inhibited in growth by TGF-α monoclonal antibody. These results indicated that secreted TGF-α interacts with its receptor at a cell surface location. Single cell-derived TGF-α-expressing sublines grew to high saturation density in culture. These and other results imply that TGF-α exerts a growth-promoting effect on the entire NIH 3T3 cell population after secretion into the medium but little, if any, effect on the individual cell synthesizing this factor. It is concluded that the normal coding sequence for TGF-α is not a direct-acting oncogene when overexpressed in NIH 3T3 cells

  1. Analysis of the miRNA-mRNA networks in malignant transformation BEAS-2B cells induced by alpha-particles.

    Science.gov (United States)

    Nie, Ji-Hua; Chen, Zhi-Hai; Shao, Chun-Lin; Pei, Wei-Wei; Zhang, Jie; Zhang, Shu-Yu; Jiao, Yang; Tong, Jian

    2016-01-01

    The aim of this study was to determine the toxicity induced by irradiation with alpha-particles on malignant transformation of immortalized human bronchial epithelial cells (BEAS-2B) using miRNA-mRNA networks. The expression of BEAS-2B cells was determined by measuring colony formation, mtDNA, mitochondrial membrane potential (MMP), and ROS levels. Changes in BEAS-2B cell gene expression were observed and quantified using microarrays that included an increase in 157 mRNA and 20 miRNA expression and a decrease in 77 mRNA and 48 miRNA. Bioinformatic software was used to analyze these different mRNA and miRNA, which indicated that miR-107 and miR-494 play an important role in alpha-particles-mediated cellular malignant transformation processes. The pathways related to systemic lupus erythematosus, cytokine-cytokine receptor interaction, MAPK signaling pathway, regulation of actin cytoskeleton, and cell adhesion molecules (CAMs) were stimulated, while those of ribosome, transforming growth factor (TGF)-beta signaling pathway, and metabolic pathways were inhibited. Data suggest that miRNA and mRNA play a crucial role in alpha-particles-mediated malignant transformation processes. It is worth noting that three target genes associated with lung cancer were identified and upregulated PEG 10 (paternally expressed gene 10), ARHGAP26, and IRS1. PMID:27267825

  2. Role of interferon-γ on smooth muscle cells proliferation and migration after balloon injury by inhibiting transforming growth factor-β signal pathway

    Institute of Scientific and Technical Information of China (English)

    MEI Yu; WANG Gui-zhao; HUANG Yong-lin

    2003-01-01

    @@ Objective Restenosis after balloon angioplasty resuits from abnormal proliferation of phenotypically modulated vascular smooth muscle cells (SMCs) that migrate and synthesize large amounts of extracellular matrix. A vafety of growth factors have been shown to play a role in the development of restenotic lesions including transforming growth factor-β (TGF-β).

  3. Transforming growth factor-beta 1 downregulates dexamethasone-induced tetranectin gene expression during the in vitro mineralization of the human osteoblastic cell line SV-HFO

    DEFF Research Database (Denmark)

    Iba, K; Sawada, N; Chiba, H;

    1995-01-01

    treatment as evidenced by Northern blotting. When transforming growth factor-beta 1 (TGF-beta 1) was added together with dexamethasone to the SV-HFO cell cultures, the mineralization process was markedly suppressed and the expression of tetra nectin and alkaline phosphatase was downregulated in a dose...

  4. Hydroquinone-induced malignant transformation of TK6 cells by facilitating SIRT1-mediated p53 degradation and up-regulating KRAS.

    Science.gov (United States)

    Chen, Yuting; Chen, Jiajia; Yun, Lin; Xu, Longmei; Liu, Jiaxian; Xu, Yongchun; Yang, Hui; Liang, Hairong; Tang, Huanwen

    2016-09-30

    Hydroquinone (HQ), known as one of the metabolic products of benzene, causes a number of hematologic malignancies. The study evaluated the potential mechanism of Sirtuin 1 (SIRT1) in HQ-induced TK6 cell malignant transformation. The data of our study show that short term exposure of TK6 cells to HQ led to a decrease expression of SIRT1. Knockdown of SIRT1 sensitized to the HQ-induced apoptosis in vitro and increased the expression of p53, p21 and γ-H2AX. Furthermore, chronic HQ-treated (20μM once a week for 19 weeks) caused carcinogenic transformation and was confirmed by abnormal cell proliferation, matrix metalloproteinase 9(MMP9) and subcutaneous tumor formation in nude mice. SIRT1 increased KRAS expression, and decreased H3K9 and H3K18 acetylation, inhibited p53 signaling and the level of caspase-3 in HQ-induced transformation cells. Taken together, these data suggest that SIRT1 is involved in HQ-induced malignant transformation associated with suppressing p53 signaling and activation of KRAS. PMID:27515134

  5. Classification and structural analysis of live and dead salmonella cells using fourier transform infrared (FT-IR) spectroscopy and principle component analysis (PCA)

    Science.gov (United States)

    Fourier Transform Infrared Spectroscopy (FT-IR) was used to detect Salmonella typhimurium and Salmonella enteritidis foodborne bacteria and distinguish between live and dead cells of both serotypes. Bacteria were loaded individually on the ZnSe Attenuated Total Reflection (ATR) crystal surface and s...

  6. Intervention effect of pinelliae decoction for purging stomach-fire on malignant transformation of bone marrow mesenchymal stem cells in the gastric cancer microenvironment

    Science.gov (United States)

    Liu, Xi-Ping; Ming, Hai-Xia; Li, Pei-Qing

    2016-01-01

    Objective: The study aimed to simulate the microenvironment of gastric cancer to promote the malignant transformation of bone marrow mesenchymal stem cells (BMSCs) and further evaluate the effect of Pinelliae Decoction for Purging Stomach-Fire and its disassembled prescriptions on BMSCs. Methods: Transwell co-culture was performed on the human gastric cancer cell strains BGC-823 and BMSCs to simulate the microenvironment of gastric cancer. The drug-containing serum prepared by Pinelliae Decoction for Purging Stomach-Fire and its disassembled prescriptions was used, and its influence on BMSCs with malignant transformation was observed. Results: BMSCs were harvested successfully from the rat bone marrow, and flow cytometer identification indicated that CD44+/CD34- cells accounted for 70.64%. The co-culture of BGC-823 cells can induce malignant transformation of BMSCs. And the drug-containing serum can induce G2 phase arrest, inhibit cell proliferation, simultaneously inhibit TERT and c-myc expression, lower the cellular ability of chemotactic migration, inhibit the tumor-forming ability of BGC-823 in nude rats and promote the tumor apoptosis. Conclusion: The effective components of Pinelliae Decoction for Purging Stomach-Fire in gastric cancer treatment are pinelliae and dried ginger, and the main acting mechanism is to inhibit tumor cell proliferation and chemotactic migration and promote apoptosis. PMID:27508014

  7. Genetic Transformation of Bacteria.

    Science.gov (United States)

    Moss, Robert.

    1991-01-01

    An activity in which students transform an ampicillin-sensitive strain of E. coli with a plasmid containing a gene for ampicillin resistance is described. The procedure for the preparation of competent cells and the transformation of competent E. coli is provided. (KR)

  8. Expression of parathyroid hormone-related protein during immortalization of human peripheral blood mononuclear cells by HTLV-1: Implications for transformation

    Directory of Open Access Journals (Sweden)

    Nadella Kiran S

    2008-06-01

    Full Text Available Abstract Background Adult T-cell leukemia/lymphoma (ATLL is initiated by infection with human T-lymphotropic virus type-1 (HTLV-1; however, additional host factors are also required for T-cell transformation and development of ATLL. The HTLV-1 Tax protein plays an important role in the transformation of T-cells although the exact mechanisms remain unclear. Parathyroid hormone-related protein (PTHrP plays an important role in the pathogenesis of humoral hypercalcemia of malignancy (HHM that occurs in the majority of ATLL patients. However, PTHrP is also up-regulated in HTLV-1-carriers and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP patients without hypercalcemia, indicating that PTHrP is expressed before transformation of T-cells. The expression of PTHrP and the PTH/PTHrP receptor during immortalization or transformation of lymphocytes by HTLV-1 has not been investigated. Results We report that PTHrP was up-regulated during immortalization of lymphocytes from peripheral blood mononuclear cells by HTLV-1 infection in long-term co-culture assays. There was preferential utilization of the PTHrP-P2 promoter in the immortalized cells compared to the HTLV-1-transformed MT-2 cells. PTHrP expression did not correlate temporally with expression of HTLV-1 tax. HTLV-1 infection up-regulated the PTHrP receptor (PTH1R in lymphocytes indicating a potential autocrine role for PTHrP. Furthermore, co-transfection of HTLV-1 expression plasmids and PTHrP P2/P3-promoter luciferase reporter plasmids demonstrated that HTLV-1 up-regulated PTHrP expression only mildly, indicating that other cellular factors and/or events are required for the very high PTHrP expression observed in ATLL cells. We also report that macrophage inflammatory protein-1α (MIP-1α, a cellular gene known to play an important role in the pathogenesis of HHM in ATLL patients, was highly expressed during early HTLV-1 infection indicating that, unlike PTHrP, its expression was

  9. α-transforming growth factor secreted by untransformed bovine anterior pituitary cells in culture. I. Purification from conditioned medium

    International Nuclear Information System (INIS)

    A 6-kDa α-transforming growth factor (TGF) was purified 100,000-fold to homogeneity from the culture fluid conditioned by normal bovine anterior pituitary-derived cells. Initial purification of the acid-soluble TGF from concentrated conditioned medium was achieved by Bio-Gel P-60 gel filtration (apparent molecular mass of 9 kDa). After the Bio-Gel step, three different steps of reverse-phase fast-protein liquid chromatography on the same Pharmacia C18 column, using linear acetonitrile gradients, gave complete purification. The ion-pairing agents used in the three consecutive steps were: 0.1% trifluoroacetic acid, 0.13% heptafluorobutyric acid, and again, 0.1% trifluoroacetic acid at a shallower gradient. Homogeneity was confirmed by reverse-phase high performance liquid chromatography, and by polyacrylamide gel electrophoresis, where TGF visualization was facilitated by autoradiography of 125I-TGF. The 125I-TGF bound to epidermal growth factor (EGF) receptors and after elution ran identically to the starting material. The molecular mass of TGF is 6 kDa by polyacrylamide gel electrophoresis and 6.6 kDa by amino acid analysis. The amino acid composition of bovine TGF is similar to that of rat or human αTGF and distinct from epidermal growth factor. Colony-stimulating activity was lost after purification, but the TGF retained its ability to stimulate thymidine uptake by quiescent cells. This mitogenic activity could be blocked completely by anti-EGF-receptor monoclonal antibodies, indicating that the activity was mediated through the EGF-receptor

  10. Enhancing rice resistance to fungal pathogens by transformation with cell wall degrading enzyme genes from Trichoderma atroviride

    Institute of Scientific and Technical Information of China (English)

    刘梅; 孙宗修; 朱洁; 徐同; HARMANGaryE; LORITOMatteo

    2004-01-01

    Three genes encoding for fungal cell wall degrading enzymes (CWDEs), ech42, nag70 and gluc78 from the biocontrol fungus Trichoderma atroviride were inserted into the binary vector pCAMBIA1305.2 singly and in all possible combinations and transformed to rice plants. More than 1800 independently regenerated plantlets in seven different populations (for each of the three genes and each of the four gene combinations) were obtained. The ech42 gene encoding for an endochitinase increased resistance to sheath blight caused by Rhizoctonia solani, while the exochitinase-encoding gene, nag70, had lesser effect. The expression level of endochitinase but exochitinase was correlated with disease resistance. Nevertheless, exochitinase enhanced the effect of endochitinase on disease resistance when the two genes co-expressed in transgenics. Resistance to Magnaporthe grisea was found in all kinds of regenerated plants including that with single gluc78. A few lines expressing either ech42 or nag70 gene were immune to the disease. Transgenic plants are being tested to further evaluate disease resistance at field level. This is the first report of multiple of expression of genes encoding CWDEs from Trichoderma atroviride that result in resistance to blast and sheath blight in rice.

  11. Multiple abiotic stress tolerance of the transformants yeast cells and the transgenic Arabidopsis plants expressing a novel durum wheat catalase.

    Science.gov (United States)

    <