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Sample records for transformed cells developed

  1. Radiogenic cell transformation and carcinogenesis

    Science.gov (United States)

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

    1995-01-01

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

  2. Distinctive transforming genes in x-ray-transformed mammalian cells

    International Nuclear Information System (INIS)

    Borek, C.; Ong, A.; Mason, H.

    1987-01-01

    DNAs from hamster embryo cells and mouse C3H/10T1/2 cells transformed in vitro by x-irradiation into malignant cells transmit the radiation transformation phenotype by producing transformed colonies (transfectants) in two mouse recipient lines, the NIH 3T3 and C3H/101/2 cells, and in a rat cell line, the Rat-2 cells. DNAs from unirradiated cells or irradiated and visibly untransformed cells do not produce transformed colonies. The transfectant grow in agar and form tumors in nude mice. Treatment of the DNAs with restriction endonucleases prior to transfection indicates that the same transforming gene (oncogene) is present in each of the transformed mouse cells and is the same in each of the transformed hamster cells. Southern blot analysis of 3T3 or Rat-2 transfectants carrying oncogenes from radiation-transformed C3H/10T1/2 or hamster cells indicates that the oncogenes responsible for the transformation of 3T3 cells are not the Ki-ras, Ha-ras, N-ras genes, nor are they neu, trk, raf, abl, or fms. The work demonstrates that DNAs from mammalian cells transformed into malignancy by direct exposure in vitro to radiation contain genetic sequences with detectable transforming activity in three recipient cell lines. The results provide evidence that DNA is the target of radiation carcinogenesis induced at a cellular level in vitro. The experiments indicate that malignant radiogenic transformation in vitro of hamster embryo and mouse C3H/10T1/2 cells involves the activation of unique non-ras transforming genes, which heretofore have not been described

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

    International Nuclear Information System (INIS)

    Huberman, E.; Langenbach, R.

    1977-01-01

    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

  4. Mechanisms of radiation-induced neoplastic cell transformation

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    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.

  5. Mechanisms of radiation-induced neoplastic cell transformation

    International Nuclear Information System (INIS)

    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

  6. Development of secondary cell wall in cotton fibers as examined with Fourier transform-infrared spectroscopy

    Science.gov (United States)

    Our presentation will focus on continuing efforts to examine secondary cell wall development in cotton fibers using infrared Spectroscopy. 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-...

  7. Recent Developments of the Local Effect Model (LEM) - Implications of clustered damage on cell transformation

    Science.gov (United States)

    Elsässer, Thilo

    Exposure to radiation of high-energy and highly charged ions (HZE) causes a major risk to human beings, since in long term space explorations about 10 protons per month and about one HZE particle per month hit each cell nucleus (1). Despite the larger number of light ions, the high ionisation power of HZE particles and its corresponding more complex damage represents a major hazard for astronauts. Therefore, in order to get a reasonable risk estimate, it is necessary to take into account the entire mixed radiation field. Frequently, neoplastic cell transformation serves as an indicator for the oncogenic potential of radiation exposure. It can be measured for a small number of ion and energy combinations. However, due to the complexity of the radiation field it is necessary to know the contribution to the radiation damage of each ion species for the entire range of energies. Therefore, a model is required which transfers the few experimental data to other particles with different LETs. We use the Local Effect Model (LEM) (2) with its cluster extension (3) to calculate the relative biological effectiveness (RBE) of neoplastic transformation. It was originally developed in the framework of hadrontherapy and is applicable for a large range of ions and energies. The input parameters for the model include the linear-quadratic parameters for the induction of lethal events as well as for the induction of transformation events per surviving cell. Both processes of cell inactivation and neoplastic transformation per viable cell are combined to eventually yield the RBE for cell transformation. We show that the Local Effect Model is capable of predicting the RBE of neoplastic cell transformation for a broad range of ions and energies. The comparison of experimental data (4) with model calculations shows a reasonable agreement. We find that the cluster extension results in a better representation of the measured RBE values. With this model it should be possible to better

  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. The relevance of cell transformation to carcinogenesis in vivo

    International Nuclear Information System (INIS)

    Little, J.B.

    1989-01-01

    Despite the caveats concerning rodent as opposed to human cell transformation systems, the author concludes there are several areas in which cell transformation studies with rodent cells have shown clear relevance to carcinogenesis in vivo, especially studies of carcinogenic effects of high LET radiation, particularly dependence on dose rate. In vitro studies firmly established the generality of promotion by phorbol esters tumour promotors. Initial studies on suppression of transformation, notably by protease inhibitors, has led to the confirmation of this phenomenon in in vivo carcinogenesis; development of inhibitor preparations from natural sources suitable for long-term supplementation in human diet, is under investigation. The potential importance of these modifiers is further emphasized by mechanistic studies suggesting that radiation may initiate a large fraction of exposed cell population, and expression of transformation may be controlled to a large extent by environmental conditions including the presence of promoting or suppressing agents. Finally, cell transformation systems offer the opportunity for mechanistic studies of the initial stages of carcinogenesis. Provocative results have arisen in several areas consistent with findings in experimental animals. (author)

  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. X-ray-induced in vitro neoplastic transformation of human diploid cells

    International Nuclear Information System (INIS)

    Borek, C.

    1980-01-01

    Techniques have recently been developed to identify and score quantitatively neoplastic transformation caused by x-rays in cultured cells derived from rodents. The present report describes for the first time the neoplastic transformation in vitro of human diploid cells by x-ray irradiation into cells which can progress in vitro into advanced stages of neoplastic development, namely, to form colonies in agar and give rise to tumors when injected into nude mice

  12. Mammalian cell transformation: Mechanisms of carcinogenesis and assays for carcinogens

    International Nuclear Information System (INIS)

    Barrett, J.C.; Tennant, R.W.

    1985-01-01

    This book contains nine sections, each consisting of several papers. The section titles are: Molecular Changes in Cell Transformation; Differentiation, Growth Control, and Cell Transformation; Mutagenesis and Cell Transformation; Tumor Promotion and Cell Transformation; Mechanisms of Transformation of Human Fibroblasts; Mechanisms of Transformation of Epithelial Cells; Mechanisms of C 3 H 10T12 Cell Transformation; Mechanisms of Radiation-Induced Cell Transformation; and Use of Cell Transformation Assays for Carcinogen Testing

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

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    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.

  14. Radiation-induced transformation in oncogene primed C3H/10T1/2 cells; a new system for analysis of multi-step transformation in vitro

    International Nuclear Information System (INIS)

    Drozdoff, V.V.

    1988-01-01

    Several established rodent cell lines, such as C3H/10T1/2 fibroblasts, have been developed to study radiation and chemically-induced malignant transformation. Most experimental evidence has supported the idea that transformation in 10T1/2 cells involved at least two steps but that the apparent frequency of transformation depends on the density of plated cells. A new approach is presented here for studying radiation-induced transformation. An oncogene primed cell system (C3H-myc) was developed by introducing a constitutively active mouse c-myc gene into 10T1/2 cells. A primary goal was to determine if the introduction of an activated oncogene could substitute for one of the required steps in radiation-induced transformation. Results are presented that show that the expression of the exogenous myc gene significantly increased the frequency of radiation-induced transformation in these cells. Subculture experiments performed to analyze the kinetics of transformation in C3H-myc cells and reconstruction experiments allowing the effects of normal cells on radiation-induced transformants to be determined indicated that transformed cells arose very shortly after irradiation. These results support the conclusion that a radiation-induced event can complement the effect of myc in C3H-myc cells and directly result in transformation. This system thus provides an opportunity to isolate early steps in radiation-induced transformation and should facilitate the identification and analysis of these events

  15. 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...

  16. Biolistic transformation of tobacco and maize suspension cells using bacterial cells as microprojectiles.

    Science.gov (United States)

    Rasmussen, J L; Kikkert, J R; Roy, M K; Sanford, J C

    1994-01-01

    We have used both Escherichia coli cells and Agrobacterium tumefaciens cells as microprojectiles to deliver DNA into suspension-cultured tobacco (Nicotiana tabacum L. line NT1) cells using a helium powered biolistic device. In addition, E. coli cells were used as microprojectiles for the transformation of suspension-cultured maize (Zea mays cv. Black Mexican Sweet) cells. Pretreating the bacterial cells with phenol at a concentration of 1.0%, and combining the bacterial cells with tungsten particles increased the rates of transformation. In N. tabacum, we obtained hundreds of transient transformants per bombardment, but were unable to recover any stable transformants. In Z. mays we obtained thousands of transient transformants and an average of six stable transformants per bombardment. This difference is discussed.

  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

    International Nuclear Information System (INIS)

    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

  19. Transformation of human mesenchymal cells and skin fibroblasts into hematopoietic cells.

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    David M Harris

    Full Text Available Patients with prolonged myelosuppression require frequent platelet and occasional granulocyte transfusions. Multi-donor transfusions induce alloimmunization, thereby increasing morbidity and mortality. Therefore, an autologous or HLA-matched allogeneic source of platelets and granulocytes is needed. To determine whether nonhematopoietic cells can be reprogrammed into hematopoietic cells, human mesenchymal stromal cells (MSCs and skin fibroblasts were incubated with the demethylating agent 5-azacytidine (Aza and the growth factors (GF granulocyte-macrophage colony-stimulating factor and stem cell factor. This treatment transformed MSCs to round, non-adherent cells expressing T-, B-, myeloid-, or stem/progenitor-cell markers. The transformed cells engrafted as hematopoietic cells in bone marrow of immunodeficient mice. DNA methylation and mRNA array analysis suggested that Aza and GF treatment demethylated and activated HOXB genes. Indeed, transfection of MSCs or skin fibroblasts with HOXB4, HOXB5, and HOXB2 genes transformed them into hematopoietic cells. Further studies are needed to determine whether transformed MSCs or skin fibroblasts are suitable for therapy.

  20. Defective repair of UV-damaged DNA in human tumor and SV40-transformed human cells but not in adenovirus-transformed human cells

    International Nuclear Information System (INIS)

    Rainbow, A.J.

    1989-01-01

    The DNA repair capacities of five human tumor cell lines, one SV40-transformed human cell line and one adenovirus-transformed human cell line were compared with that of normal human fibroblasts using a sensitive host cell reactivation (HCR) technique. Unirradiated and UV-irradiated suspensions of adenovirus type 2 (Ad 2) were assayed for their ability to form viral structural antigens (Vag) in the various cell types using immunofluorescent staining. The survival of Vag formation for UV-irradiated Ad 2 was significantly reduced in all the human tumor cell lines and the SV40-transformed human line compared to the normal human fibroblasts, but was apparently normal in the adenovirus-transformed human cells. D 0 values for the UV survival of Ad 2 Vag synthesis in the tumor and virally transformed lines expressed as a percentage of that obtained on normal fibroblast strains were used as a measure of DNA repair capacity. Percent HCR values ranged from 26 to 53% in the tumor cells. These results indicate a deficiency in the repair of UV-induced DNA damage associated with human tumorigenesis and the transformation of human cells by SV40 but not the transformation of human cells by adenovirus. (author)

  1. Mitochondrial clearance by the STK38 kinase supports oncogenic Ras-induced cell transformation

    Science.gov (United States)

    Bettoun, Audrey; Surdez, Didier; Vallerand, David; Gundogdu, Ramazan; Sharif, Ahmad A.D.; Gomez, Marta; Cascone, Ilaria; Meunier, Brigitte; White, Michael A.; Codogno, Patrice; Parrini, Maria Carla; Camonis, Jacques H.; Hergovich, Alexander

    2016-01-01

    Oncogenic Ras signalling occurs frequently in many human cancers. However, no effective targeted therapies are currently available to treat patients suffering from Ras-driven tumours. Therefore, it is imperative to identify downstream effectors of Ras signalling that potentially represent promising new therapeutic options. Particularly, considering that autophagy inhibition can impair the survival of Ras-transformed cells in tissue culture and mouse models, an understanding of factors regulating the balance between autophagy and apoptosis in Ras-transformed human cells is needed. Here, we report critical roles of the STK38 protein kinase in oncogenic Ras transformation. STK38 knockdown impaired anoikis resistance, anchorage-independent soft agar growth, and in vivo xenograft growth of Ras-transformed human cells. Mechanistically, STK38 supports Ras-driven transformation through promoting detachment-induced autophagy. Even more importantly, upon cell detachment STK38 is required to sustain the removal of damaged mitochondria by mitophagy, a selective autophagic process, to prevent excessive mitochondrial reactive oxygen species production that can negatively affect cancer cell survival. Significantly, knockdown of PINK1 or Parkin, two positive regulators of mitophagy, also impaired anoikis resistance and anchorage-independent growth of Ras-transformed human cells, while knockdown of USP30, a negative regulator of PINK1/Parkin-mediated mitophagy, restored anchorage-independent growth of STK38-depleted Ras-transformed human cells. Therefore, our findings collectively reveal novel molecular players that determine whether Ras-transformed human cells die or survive upon cell detachment, which potentially could be exploited for the development of novel strategies to target Ras-transformed cells. PMID:27283898

  2. Evaluation of existing and development of new human epithelial cell transformation systems and determination of their potential in radiation protection studies

    International Nuclear Information System (INIS)

    Seymour, C.B.; Riches, A.C.; Pertusa, J.

    1993-01-01

    The aims of the project are to collaborate on a systematic study of radiation induced oncogenic transformation using different human epithelial cell lines and to study initiation of carcinogenesis by radiation by examining changes which occur in molecular, genetic and morphological features of normal human cells after exposure to radiation. This more longterm aim is at present being approached at a mainly qualitative level. This approach provides the next logical step in developing a full understanding of radiation-induced transformation of human epithelial cells. Objectives and results of five contributions to the project for the reporting period are presented. (R.P.) 20 refs., 4 figs

  3. Development of insusceptibility to serum factor during the radiation transformation process

    International Nuclear Information System (INIS)

    Terasima, T.; Yasukawa, M.; Kimura, M.

    1983-01-01

    The effects of using different assay sera on the X-ray-induced transformation yield in 10T1/2 mouse cells were studied. The use of newborn calf assay serum gave a 5 x greater value of transformation than foetal calf serum. This difference in transformation yield with different assay sera was used to investigate the time interval required for the development of insusceptibility of cells to serum factor. Sequential shifting from low yield sera (LYS) to high yield sera (HYS) showed that the radiation-initiated cells were most susceptible to HYS at the beginning of the assay culture but finally became insusceptible within 2 weeks of incubation. (U.K.)

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

    International Nuclear Information System (INIS)

    Yoshii, Hanako; Watanabe, Masami

    2009-01-01

    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)

  5. β-carotene and canthaxanthin inhibit chemically- and physically-induced transformation in 10T1/2 cells

    International Nuclear Information System (INIS)

    Pung, A.; Rundhaug, J.E.; Yoshizawa, C.N.; Bertram, J.S.

    1988-01-01

    We have studied the effects of β-carotene (β-C), a vitamin A precursor of plant origin, and canthaxanthin (CTX), a non-provitamin A carotenoid, on the neoplastic transformation of C3H/10T1/2 murine fibroblast cells. We show that both β-C and CTX inhibit 3-methylcholanthrene (MCA)-induced transformation. Both carotenoids failed to inhibit X-ray-induced transformation when the cells were treated prior to and during irradiation. However, when the drugs were added 1 week after X-irradiation and maintained in the medium thereafter, both carotenoids inhibited subsequent development of transformed foci in a dose-dependent manner. Again, CTX was more effective than β-C. The inhibition of MCA-induced transformation was reversible; upon removal of the drug, transformed foci developed within 2 weeks, indicating that the carotenoids were not specifically toxic to initiated cells. Although both carotenoids caused a small dose-dependent decrease in the growth rate of both parental and initiated 10T1/2 cells, they did not markedly affect colony size or number when the cells were treated as in the transformation assays, nor did they influence the expression of neoplasia of two transformed cell lines. We suggest that the carotenoids' lipid anti-oxidant properties may be responsible for their inhibitory actions on transformation. (author)

  6. In vitro cell transformation induced by synthetic amorphous silica nanoparticles.

    Science.gov (United States)

    Fontana, Caroline; Kirsch, Anaïs; Seidel, Carole; Marpeaux, Léa; Darne, Christian; Gaté, Laurent; Remy, Aurélie; Guichard, Yves

    2017-11-01

    Synthetic amorphous silica nanoparticles (SAS) are among the most widely produced and used nanomaterials, but little is known about their carcinogenic potential. This study aims to evaluate the ability of four different SAS, two precipitated, NM-200 and NM-201, and two pyrogenic, NM-202 and NM-203, to induce the transformation process. For this, we used the recently developed in vitro Bhas 42 cell transformation assay (CTA). The genome of the transgenic Bhas 42 cells contains several copies of the v-Ha-ras gene, making them particularly sensitive to tumor-promoter agents. The Bhas 42 CTA, which includes an initiation assay and a promotion assay, was validated in our laboratory using known soluble carcinogenic substances. Its suitability for particle-type substances was verified by using quartz Min-U-Sil 5 (Min-U-Sil) and diatomaceous earth (DE) microparticles. As expected given their known transforming properties, Min-U-Sil responded positively in the Bhas 42 CTA and DE responded negatively. Transformation assays were performed with SAS at concentrations ranging from 2μg/cm 2 to 80μg/cm 2 . Results showed that all SAS have the capacity to induce transformed foci, interestingly only in the promotion assay, suggesting a mode of action similar to tumor-promoter substances. NM-203 exhibited transforming activity at a lower concentration than the other SAS. In conclusion, this study showed for the first time the transforming potential of different SAS, which act as tumor-promoter substances in the Bhas 42 model of cell transformation. Copyright © 2017 Elsevier B.V. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    Amanda R. Panfil

    2015-12-01

    Full Text Available 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.

  8. X-ray-induced in vitro neoplastic transformation of human diploid cells

    International Nuclear Information System (INIS)

    Borek, C.

    1980-01-01

    The neoplastic transformation, in vitro, of human diploid cells by x-ray irradiation into cells which can progress, in vitro, into advanced stages of neoplastic development is described. The cells are shown to form colonies in agar and to give rise to tumours when injected into nude mice. (U.K.)

  9. Neoplastic progression of rat tracheal epithelial cells involves resistance to transforming growth factor beta

    International Nuclear Information System (INIS)

    Hubbs, A.F.; Hahn, F.F.; Thomassen, D.G.

    1988-01-01

    Primary, transformed, and tumor-derived rat tracheal epithelial (RTE) cells were grown in serum-free medium containing 0 to 300 pg/mL transforming growth factor beta (TGFβ) markedly inhibited the growth of primary RTE cells with a 50% drop in the efficiency of colony formation seen at TGFβ concentrations between 10 and 30 pg/ mL. The effect of TGFβ on preneoplastic RTE cells was similar to the effect on normal primary RTE cells. Cell lines established from tumors produced by inoculation of transformed RTE cells into nude mice were relatively resistant to -TGFβ-induced growth inhibition. Resistance to TGFβ-induced growth inhibition, therefore, appears to be a late event in the development of neoplasia. (author)

  10. Cancer cell detection and classification using transformation invariant template learning methods

    International Nuclear Information System (INIS)

    Talware, Rajendra; Abhyankar, Aditya

    2011-01-01

    In traditional cancer cell detection, pathologists examine biopsies to make diagnostic assessments, largely based on cell morphology and tissue distribution. The process of image acquisition is very much subjective and the pattern undergoes unknown or random transformations during data acquisition (e.g. variation in illumination, orientation, translation and perspective) results in high degree of variability. Transformed Component Analysis (TCA) incorporates a discrete, hidden variable that accounts for transformations and uses the Expectation Maximization (EM) algorithm to jointly extract components and normalize for transformations. Further the TEMPLAR framework developed takes advantage of hierarchical pattern models and adds probabilistic modeling for local transformations. Pattern classification is based on Expectation Maximization algorithm and General Likelihood Ratio Tests (GLRT). Performance of TEMPLAR is certainly improved by defining area of interest on slide a priori. Performance can be further enhanced by making the kernel function adaptive during learning. (author)

  11. 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.

    2015-01-01

    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

  12. Cancer Stem-Like Cells Accumulated in Nickel-Induced Malignant Transformation

    Science.gov (United States)

    Wang, Lei; Fan, Jia; Hitron, John Andrew; Son, Young-Ok; Wise, James T.F.; Roy, Ram Vinod; Kim, Donghern; Dai, Jin; Pratheeshkumar, Poyil; Zhang, Zhuo; Shi, Xianglin

    2016-01-01

    Nickel compounds are known as human carcinogens. Chronic environmental exposure to nickel is a worldwide health concern. Although the mechanisms of nickel-induced carcinogenesis are not well understood, recent studies suggest that stem cells/cancer stem cells are likely important targets. This study examines the role of cancer stem cells in nickel-induced cell transformation. The nontransformed human bronchial epithelial cell line (Beas-2B) was chronically exposed to nickel chloride for 12 months to induce cell transformation. Nickel induced Beas-2B cell transformation, and cancer stem-like cells were enriched in nickel-transformed cell (BNiT) population. The BNiT cancer stem-like cells demonstrated enhanced self-renewal and distinctive differentiation properties. In vivo tumorigenesis studies show that BNiT cancer stem-like cells possess a high tumor-initiating capability. It was also demonstrated that superoxide dismutase 1 was involved in the accumulation of cancer stem-like cells; the regulation of superoxide dismutase 1 expression was different in transformed stem-like cells and nontransformed. Overall, the accumulation of stem-like cells and their enhanced stemness functions contribute to nickel-induced tumorigenesis. Our study provides additional insight into the mechanisms by which metals or other chemicals can induce carcinogenesis. PMID:26962057

  13. Neoplastic cell transformation by high-LET radiation - Molecular mechanisms

    Science.gov (United States)

    Yang, Tracy Chui-Hsu; Craise, Laurie M.; Tobias, Cornelius A.; Mei, Man-Tong

    1989-01-01

    Quantitative data were collected on dose-response curves of cultured mouse-embryo cells (C3H10T1/2) irradiated with heavy ions of various charges and energies. Results suggests that two breaks formed on DNA within 80 A may cause cell transformation and that two DNA breaks formed within 20 A may be lethal. From results of experiments with restriction enzymes which produce DNA damages at specific sites, it was found that DNA double strand breaks are important primary lesions for radiogenic cell transformation and that blunt-ended double-strand breaks can form lethal as well as transformational damages due to misrepair or incomplete repair in the cell. The RBE-LET relationship for high-LET radiation is similar to that for HGPRT locus mutation, chromosomal deletion, and cell transformation, indicating that common lesions may be involved in these radiation effects.

  14. Malignant human cell transformation of Marcellus Shale gas drilling flow back water

    Energy Technology Data Exchange (ETDEWEB)

    Yao, Yixin [Department of Epidemiology, Shanghai Jiaotong University School of Public Health (China); Department of Environmental Medicine, New York University School of Medicine, Tuxedo, NY 10987 (United States); Chen, Tingting [School of Material Science and Engineering, Nanjing University of Science and Technology, Nanjing 210094 (China); Shen, Steven S. [Biochemistry and Molecular Pharmaceutical, New York University School of Medicine (United States); Niu, Yingmei; DesMarais, Thomas L.; Linn, Reka; Saunders, Eric; Fan, Zhihua [Department of Environmental Medicine, New York University School of Medicine, Tuxedo, NY 10987 (United States); Lioy, Paul [Robert Wood Johnson Medical School Rutgers, The State University of New Jersey, Piscataway, NJ 08854 (United States); Kluz, Thomas; Chen, Lung-Chi [Department of Environmental Medicine, New York University School of Medicine, Tuxedo, NY 10987 (United States); Wu, Zhuangchun, E-mail: wuzhuangchun@mail.njust.edu.cn [College of Science, Donghua University, Shanghai 201620 (China); Costa, Max, E-mail: max.costa@nyumc.org [Department of Environmental Medicine, New York University School of Medicine, Tuxedo, NY 10987 (United States)

    2015-10-01

    The rapid development of high-volume horizontal hydraulic fracturing for mining natural gas from shale has posed potential impacts on human health and biodiversity. The produced flow back waters after hydraulic stimulation are known to carry high levels of saline and total dissolved solids. To understand the toxicity and potential carcinogenic effects of these wastewaters, flow back waters from five Marcellus hydraulic fracturing oil and gas wells were analyzed. The physicochemical nature of these samples was analyzed by inductively coupled plasma mass spectrometry and scanning electron microscopy/energy dispersive X-ray spectroscopy. A cytotoxicity study using colony formation as the endpoint was carried out to define the LC{sub 50} values of test samples using human bronchial epithelial cells (BEAS-2B). The BEAS-2B cell transformation assay was employed to assess the carcinogenic potential of the samples. Barium and strontium were among the most abundant metals in these samples and the same metals were found to be elevated in BEAS-2B cells after long-term treatment. BEAS-2B cells treated for 6 weeks with flow back waters produced colony formation in soft agar that was concentration dependent. In addition, flow back water-transformed BEAS-2B cells show better migration capability when compared to control cells. This study provides information needed to assess the potential health impact of post-hydraulic fracturing flow back waters from Marcellus Shale natural gas mining. - Highlights: • This is the first report of potential cytotoxicity and transforming activity of Marcellus shale gas mining flow back to mammalian cells. • Barium and Strontium were elevated in flow back water exposed cells. • Flow back water malignantly transformed cells and formed tumor in athymic nude mice. • Flow back transformed cells exhibited altered transcriptome with dysregulated cell migration pathway and adherent junction pathway.

  15. Malignant human cell transformation of Marcellus Shale gas drilling flow back water

    International Nuclear Information System (INIS)

    Yao, Yixin; Chen, Tingting; Shen, Steven S.; Niu, Yingmei; DesMarais, Thomas L.; Linn, Reka; Saunders, Eric; Fan, Zhihua; Lioy, Paul; Kluz, Thomas; Chen, Lung-Chi; Wu, Zhuangchun; Costa, Max

    2015-01-01

    The rapid development of high-volume horizontal hydraulic fracturing for mining natural gas from shale has posed potential impacts on human health and biodiversity. The produced flow back waters after hydraulic stimulation are known to carry high levels of saline and total dissolved solids. To understand the toxicity and potential carcinogenic effects of these wastewaters, flow back waters from five Marcellus hydraulic fracturing oil and gas wells were analyzed. The physicochemical nature of these samples was analyzed by inductively coupled plasma mass spectrometry and scanning electron microscopy/energy dispersive X-ray spectroscopy. A cytotoxicity study using colony formation as the endpoint was carried out to define the LC 50 values of test samples using human bronchial epithelial cells (BEAS-2B). The BEAS-2B cell transformation assay was employed to assess the carcinogenic potential of the samples. Barium and strontium were among the most abundant metals in these samples and the same metals were found to be elevated in BEAS-2B cells after long-term treatment. BEAS-2B cells treated for 6 weeks with flow back waters produced colony formation in soft agar that was concentration dependent. In addition, flow back water-transformed BEAS-2B cells show better migration capability when compared to control cells. This study provides information needed to assess the potential health impact of post-hydraulic fracturing flow back waters from Marcellus Shale natural gas mining. - Highlights: • This is the first report of potential cytotoxicity and transforming activity of Marcellus shale gas mining flow back to mammalian cells. • Barium and Strontium were elevated in flow back water exposed cells. • Flow back water malignantly transformed cells and formed tumor in athymic nude mice. • Flow back transformed cells exhibited altered transcriptome with dysregulated cell migration pathway and adherent junction pathway.

  16. 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.

  17. Mis-specified cells die by an active gene-directed process, and inhibition of this death results in cell fate transformation in Drosophila

    Science.gov (United States)

    Werz, Christian; Lee, Tom V.; Lee, Peter L.; Lackey, Melinda; Bolduc, Clare; Stein, David S.; Bergmann, Andreas

    2009-01-01

    Summary Incorrectly specified or mis-specified cells often undergo cell death or are transformed to adopt a different cell fate during development. The underlying cause for this distinction is largely unknown. In many developmental mutants in Drosophila, large numbers of mis-specified cells die synchronously, providing a convenient model for analysis of this phenomenon. The maternal mutant bicoid is particularly useful model with which to address this issue because its mutant phenotype is a combination of both transformation of tissue (acron to telson) and cell death in the presumptive head and thorax regions. We show that a subset of these mis-specified cells die through an active gene-directed process involving transcriptional upregulation of the cell death inducer hid. Upregulation of hid also occurs in oskar mutants and other segmentation mutants. In hid bicoid double mutants, mis-specified cells in the presumptive head and thorax survive and continue to develop, but they are transformed to adopt a different cell fate. We provide evidence that the terminal torso signaling pathway protects the mis-specified telson tissue in bicoid mutants from hid-induced cell death, whereas mis-specified cells in the head and thorax die, presumably because equivalent survival signals are lacking. These data support a model whereby mis-specification can be tolerated if a survival pathway is provided, resulting in cellular transformation. PMID:16280349

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

    International Nuclear Information System (INIS)

    Ren, Zhenhua; Wang, Jiayin; Zhu, Wanwan; Guan, Yunqian; Zou, Chunlin; Chen, Zhiguo; Zhang, Y. Alex

    2011-01-01

    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.

  19. Transformations of C3H 10T1/2 cells by Benzo(a)pyrene and subsequent attempts at suppression of transformed foci by untransformed cells and Vitamin A

    International Nuclear Information System (INIS)

    Lloyd, E.L.; Gemmell, M.A.

    1978-01-01

    The mouse embryo cell line (C3H 10T1/2 CL8) has been shown here, in agreement with findings by others, to be transformed by benzo(a)pyrene (BP). Transformation studies were carried out at two different concentrations (0.25 μg BP/ml and 2.5 μg BP/ml) and two different cell densities (200 and 1000 cells/60 mm dish). Transformation frequencies per surviving cell were found to be greatest when the higher concentration of BP was used with the lower cell density. A comparison of these results with earlier alpha-irradiation experiments demonstrated the greater effectiveness of BP as a transforming agent in this cell system, although the foci produced by the two agents were morphologically similar. Attempts made to eliminate the expression of BP transformed foci by two different techniques were unsuccessful, although one of these had previously been shown to be effective with cells transformed by alpha particle irradiation. The two systems tested were treatment with retinyl acetate, a common nutritional form of Vitamin A and the previously successful technique - growth of transformed cells with large numbers of untransformed cells. The differences between the BP-induced transformations and those induced by alpha particle irradiation may result from intrinsic differences in the mechanism of action of the two carcinogenic agents, differences in the number of cell generations between the induction of the transformed foci and the subsequent treatment of the cells, or genetic differences between different foci

  20. Status of superconducting power transformer development

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, R.C.; McConnell, B.W.; Mehta, S.P. [and others

    1996-03-01

    Development of the superconducting transformer is arguably the most difficult of the ac power applications of superconductivity - this is because of the need for very low ac losses, adequate fault and surge performance, and the rigors of the application environment. This paper briefly summarizes the history of superconducting transformer projects, reviews the key issues for superconducting transformers, and examines the status of HTS transformer development. Both 630-kVA, three-phase and 1-MVA single phase demonstration units are expected to operate in late 1996. Both efforts will further progress toward the development of economical and performance competitive superconducting transformers.

  1. Repair-dependent cell radiation survival and transformation: an integrated theory

    International Nuclear Information System (INIS)

    Sutherland, John C

    2014-01-01

    The repair-dependent model of cell radiation survival is extended to include radiation-induced transformations. The probability of transformation is presumed to scale with the number of potentially lethal damages that are repaired in a surviving cell or the interactions of such damages. The theory predicts that at doses corresponding to high survival, the transformation frequency is the sum of simple polynomial functions of dose; linear, quadratic, etc, essentially as described in widely used linear-quadratic expressions. At high doses, corresponding to low survival, the ratio of transformed to surviving cells asymptotically approaches an upper limit. The low dose fundamental- and high dose plateau domains are separated by a downwardly concave transition region. Published transformation data for mammalian cells show the high-dose plateaus predicted by the repair-dependent model for both ultraviolet and ionizing radiation. For the neoplastic transformation experiments that were analyzed, the data can be fit with only the repair-dependent quadratic function. At low doses, the transformation frequency is strictly quadratic, but becomes sigmodial over a wider range of doses. Inclusion of data from the transition region in a traditional linear-quadratic analysis of neoplastic transformation frequency data can exaggerate the magnitude of, or create the appearance of, a linear component. Quantitative analysis of survival and transformation data shows good agreement for ultraviolet radiation; the shapes of the transformation components can be predicted from survival data. For ionizing radiations, both neutrons and x-rays, survival data overestimate the transforming ability for low to moderate doses. The presumed cause of this difference is that, unlike UV photons, a single x-ray or neutron may generate more than one lethal damage in a cell, so the distribution of such damages in the population is not accurately described by Poisson statistics. However, the complete

  2. 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.

  3. Depleted uranium induces neoplastic transformation in human lung epithelial cells.

    Science.gov (United States)

    Xie, Hong; LaCerte, Carolyne; Thompson, W Douglas; Wise, John Pierce

    2010-02-15

    Depleted uranium (DU) is commonly used in military armor and munitions, and thus, exposure of soldiers and noncombatants is frequent and widespread. Previous studies have shown that DU has both chemical and radiological toxicity and that the primary route of exposure of DU to humans is through inhalation and ingestion. However, there is limited research information on the potential carcinogenicity of DU in human bronchial cells. Accordingly, we determined the neoplastic transforming ability of particulate DU to human bronchial epithelial cells (BEP2D). We observed the loss of contact inhibition and anchorage independent growth in cells exposed to DU after 24 h. We also characterized these DU-induced transformed cell lines and found that 40% of the cell lines exhibit alterations in plating efficiency and no significant changes in the cytotoxic response to DU. Cytogenetic analyses showed that 53% of the DU-transformed cell lines possess a hypodiploid phenotype. These data indicate that human bronchial cells are transformed by DU and exhibit significant chromosome instability consistent with a neoplastic phenotype.

  4. Initial stage of transformation of permissive cells by simian virus 40: development of resistance to productive infection.

    Science.gov (United States)

    Hahn, E C; Sauer, G

    1971-07-01

    A quantitative assay has been used to determine the conditions leading to acquisition of resistance of permissive cells to lytic infection. The number of cell colonies surviving infection depends on the occurrence of several cell divisions after infection. High yields of resistant colonies were obtained when infected, confluent cultures were released from contact inhibition 10 to 14 hr after infection. Infection of actively growing cells produced similar results, but halting further division by seeding these growing cells on confluent monolayers prevented the development of colonies. Colony formation was a direct function of multiplicities lower than 5. An inverse killing response was observed with higher multiplicities, yet colonies were produced at a multiplicity of infection as high as 50. Brief exposure of input simian virus 40 to ultraviolet light stimulated colony formation. Irradiation of the virus for longer periods of time led to reduction of colony formation at a rate slower than the rate of inactivation of viral infectivity. It was concluded that resistance is induced by simian virus 40 and that this alteration represents one of the earliest detectable characteristics of the transformation of permissive cells.

  5. Obesity Suppresses Cell-Competition-Mediated Apical Elimination of RasV12-Transformed Cells from Epithelial Tissues.

    Science.gov (United States)

    Sasaki, Ayana; Nagatake, Takahiro; Egami, Riku; Gu, Guoqiang; Takigawa, Ichigaku; Ikeda, Wataru; Nakatani, Tomoya; Kunisawa, Jun; Fujita, Yasuyuki

    2018-04-24

    Recent studies have revealed that newly emerging transformed cells are often eliminated from epithelial tissues via cell competition with the surrounding normal epithelial cells. This cancer preventive phenomenon is termed epithelial defense against cancer (EDAC). However, it remains largely unknown whether and how EDAC is diminished during carcinogenesis. In this study, using a cell competition mouse model, we show that high-fat diet (HFD) feeding substantially attenuates the frequency of apical elimination of RasV12-transformed cells from intestinal and pancreatic epithelia. This process involves both lipid metabolism and chronic inflammation. Furthermore, aspirin treatment significantly facilitates eradication of transformed cells from the epithelial tissues in HFD-fed mice. Thus, our work demonstrates that obesity can profoundly influence competitive interaction between normal and transformed cells, providing insights into cell competition and cancer preventive medicine. Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.

  6. Membrane associated ion transport enzymes in normal and transformed fibroblasts and epithelial cells

    International Nuclear Information System (INIS)

    Borek, C.

    1982-01-01

    In an effort to evaluate membrane changes associated with neoplastic transformation of fibroblasts and epithelial cells by radiation and chemicals, alterations in membrane-associated (Na + + K + )-ATPase and 5'-nucleotidase activities were investigated. Cell cultures consisted of normal and radiation transformed hamster embryo fibroblasts (HE) and mouse C3H 10T 1/2 fibroblasts, normal and chemically transformed adult rat liver epithelial cells (ARL), as well as hepatocarcinoma cells induced by the liver transformants. Transformed fibroblasts demonstrated a 1-2 fold increase in (Na + + K + )-ATPase activity over the normal, while the transformed liver epithelial cells and carcinoma cells showed a 60% and 40% decrease in activity compared to the normal values, respectively. The 5'-nucleotidase activity was 2 to 3 times higher in the transformed fibroblasts

  7. Genetic transformation of tobacco NT1 cells with Agrobacterium tumefaciens.

    Science.gov (United States)

    Mayo, Kristin J; Gonzales, Barbara J; Mason, Hugh S

    2006-01-01

    This protocol is used to produce stably transformed tobacco (Nicotiana tabacum) NT1 cell lines, using Agrobacterium tumefaciens-mediated DNA delivery of a binary vector containing a gene encoding hepatitis B surface antigen and a gene encoding the kanamycin selection marker. The NT1 cultures, at the appropriate stage of growth, are inoculated with A. tumefaciens containing the binary vector. A 3-day cocultivation period follows, after which the cultures are rinsed and placed on solid selective medium. Transformed colonies ('calli') appear in approximately 4 weeks; they are subcultured until adequate material is obtained for analysis of antigen production. 'Elite' lines are selected based on antigen expression and growth characteristics. The time required for the procedure from preparation of the plant cell materials to callus development is approximately 5 weeks. Growth of selected calli to sufficient quantities for antigen screening may require 4-6 weeks beyond the initial selection. Creation of the plasmid constructs, transformation of the A. tumefaciens line, and ELISA and Bradford assays to assess protein production require additional time.

  8. Induction of malignant transformation in CHL-1 cells by exposure to tritiated water

    International Nuclear Information System (INIS)

    Zou Shu'ai; Wang Hui

    1992-01-01

    The induction of neoplastic transformation in CHL-1 cells by low-dose-rate exposure to tritiated water was reported. CHL-1 cells were exposed to tritiated water (9.25 x 10 5 - 3.7 x 10 6 Bq/mL) for 24-96 hours and the accumulated doses were estimated to be 0.055-0.88 Gy, respectively. Neoplastic transformation was found in all exposed cell groups. The morphological study and transplantation test was carried out for demonstration malignancy of the transformed cells and the results show that they are with the morphology and behaviour for malignant tumour cells. For CHL-1 cells exposed to various doses of tritiated water, transformation rates were found to be from 3.28% to 13.0% at dose of 0.055-0.88 Gy. In order to estimate RBE of tritium for malignant transformation in CHL-1 cells, the induction of malignant transformation in CHL-1 cells by exposure to 137 Cs gamma-rays was carried out at dose rates of 0.359 Gy/24 hr and transformation rates for irradiated CHL-1 cells were found to be from 2.59% to 13.4%. Based on these data, RBE of tritium for malignant transformation in CHL-1 cells was estimated to be 1.6

  9. Neoplastic transformation of hamster embryo cells irradiated in utero and assayed in vitro

    International Nuclear Information System (INIS)

    Borek, C.; Pain, C.; Mason, H.

    1977-01-01

    It is stated that induction of neoplastic transformation in vitro by x-rays and neutrons has been reported, and the authors had previously found that transformation by x-rays could be detected at doses as low as 1 R and the rate of transformation increased with dose, reaching a peak of 1% between 150 and 300 R. This frequency of neoplastic transformation in vitro is much higher than the frequency of radiation induced tumors observed after exposing animals to similar doses of radiation. Studies are here reported showing that malignant transformed cells can be obtained from embryos irradiated in utero and assayed in vitro, and that the frequency of transformation is at least tenfold lower than when the irradiations are performed in vitro, and thus closer to the incidence in animals. Hamster embryo cells were used for the studies. Questions that arise are as follows: does the host mediate in modulating transformation by radiation; is there a repair of transforming events before they can be expressed; and how significant is the state of cells during irradiation in determining the rate of transformation. It is known from in vitro studies that cell replication is required for fixation of the transformation. With the in vitro technique cells are seeded as single cells with ample opportunity to divide. In addition they are not in contact with one another, and constitute a mixture of cell types from many tissues. In utero the situation is quite different; the embryonic cells are irradiated as tissues where there is cell to cell contact in tissue-specific arrangements, and where the rate of cell replication varies with the tissue. It remains to be seen which of these factors, if any, is responsible for the lowered yield of transformed cells characteristic of in utero as opposed to in vitro irradiation. (U.K.)

  10. EGFR T790M mutation after chemotherapy for small cell lung cancer transformation of EGFR-positive non-small cell lung cancer

    Directory of Open Access Journals (Sweden)

    Tomoaki Sonoda

    Full Text Available In non-small cell lung cancer (NSCLC with an epidermal growth factor receptor (EGFR mutation, 50%–65% of cases acquire resistance after treatment with EGFR-tyrosine kinase inhibitors (EGFR-TKIs because of an EGFR T790M point mutation and 3%–14% of these cases transformed to small cell lung cancer (SCLC. Generally, the EGFR T790M secondary mutation develops with ongoing ATP competitive inhibition. We present a case of a 76-year-old woman with lung adenocarcinoma harboring an EGFR-L858R mutation who received first-line gefitinib and developed SCLC transformation. She was administered several chemotherapy agents, including a platinum doublet. The primary lesion that showed SCLC transformation had reconverted to adenocarcinoma with EGFR L858R and T790M mutations at the time of a second re-biopsy. Therefore, she was administered osimertinib, which resulted in clinical remission. This case suggested that serial biopsies are necessary even after SCLC transformation. Keywords: NSCLC, EGFR mutation, SCLC transformation, T790M, Osimertinib

  11. 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

  12. 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.

  13. Recovery of Epstein--Barr virus from nonproducer neonatal human lymphoid cell transformants

    International Nuclear Information System (INIS)

    Wilson, G.; Miller, G.

    1979-01-01

    Lymphoid cell lines (LCL) were established by infection of two batches of human umbilical cord lymphocytes with low multiplicities of the B95-8 strain of Epstein--Barr virus. Three of the 17 lines released minute mounts of transforming virus. The rest did not, nor did they make capsid antigen. However virus could be regularly recovered by lethal x-irradiation of transformed cells followed by cocultivation with primary human umbilical cord leukocytes. By this technique transforming activity could be identified in 15 of the 17 lines. These data indicate that these nonproducer human neonatal cell transformants established by EBV infection in vitro possess sufficient genetic information to code for production of biologically active mature virions. X rays alone failed to cause a detectable increase in the number of cells with capsid antigen or to enhance extracellular virus production. EBV-positive human serum blocked rescue if it was added during the first 2 to 4 hr after cocultivation, but not thereafter. Transforming virus could be recovered from x-rayed cells which were immediately thereafter lysed by freezing and thawing. These results suggest that recovery of virus following x-ray and cocultivation is not due to activation of the intracellular virus genome. Rather, it is likely that the method detects small numbers of virions which are cell associated. While transforming virus could regularly be rescued from lymphoblastoid cell lines resulting from in vitro transformation, attempts to rescue virus from Raji or EBV-converted BJAB cells were unsuccessful. This discrepancy suggests differences in genome complexity or in genome-cell interactions in different types of EBV-transformed cells

  14. 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.

  15. Distinct protease pathways control cell shape and apoptosis in v-src-transformed quail neuroretina cells

    International Nuclear Information System (INIS)

    Neel, Benjamin D.; Aouacheria, Abdel; Nouvion, Anne-Laure; Ronot, Xavier; Gillet, Germain

    2005-01-01

    Intracellular proteases play key roles in cell differentiation, proliferation and apoptosis. In nerve cells, little is known about their relative contribution to the pathways which control cell physiology, including cell death. Neoplastic transformation of avian neuroretina cells by p60 v-src tyrosine kinase results in dramatic morphological changes and deregulation of apoptosis. To identify the proteases involved in the cellular response to p60 v-src , we evaluated the effect of specific inhibitors of caspases, calpains and the proteasome on cell shape changes and apoptosis induced by p60 v-src inactivation in quail neuroretina cells transformed by tsNY68, a thermosensitive strain of Rous sarcoma virus. We found that the ubiquitin-proteasome pathway is recruited early after p60 v-src inactivation and is critical for morphological changes, whereas caspases are essential for cell death. This study provides evidence that distinct intracellular proteases are involved in the control of the morphology and fate of v-src-transformed cells

  16. Extensive gene-specific translational reprogramming in a model of B cell differentiation and Abl-dependent transformation.

    Directory of Open Access Journals (Sweden)

    Jamie G Bates

    Full Text Available To what extent might the regulation of translation contribute to differentiation programs, or to the molecular pathogenesis of cancer? Pre-B cells transformed with the viral oncogene v-Abl are suspended in an immortalized, cycling state that mimics leukemias with a BCR-ABL1 translocation, such as Chronic Myelogenous Leukemia (CML and Acute Lymphoblastic Leukemia (ALL. Inhibition of the oncogenic Abl kinase with imatinib reverses transformation, allowing progression to the next stage of B cell development. We employed a genome-wide polysome profiling assay called Gradient Encoding to investigate the extent and potential contribution of translational regulation to transformation and differentiation in v-Abl-transformed pre-B cells. Over half of the significantly translationally regulated genes did not change significantly at the level of mRNA abundance, revealing biology that might have been missed by measuring changes in transcript abundance alone. We found extensive, gene-specific changes in translation affecting genes with known roles in B cell signaling and differentiation, cancerous transformation, and cytoskeletal reorganization potentially affecting adhesion. These results highlight a major role for gene-specific translational regulation in remodeling the gene expression program in differentiation and malignant transformation.

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

    International Nuclear Information System (INIS)

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

    1985-01-01

    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

  18. Plant cell transformation with Agrobacterium tumefaciens under simulated microgravity

    Science.gov (United States)

    Sarnatska, Veresa; Gladun, Hanna; Padalko, Svetlana

    To investigate simulated microgravity (clinorotation) effect on plant cell transformation with Agrobacterium tumefaciens and crown gall formation, the culture of primary explants of potato and Jerusalem artichoke tubers was used. It is found that the efficiency of tumor formation and development in clinorotated explants are considerably reduced. When using the explants isolated from potato tubers clinorotated for 3, 5 and 19 days, drastic reduction of formation and development of crown gall tumors was observed. Conversely, the tumor number and their development increased when potato tubers were clinorotated for one day. As was estimated by us previously, cells of Jerusalem artichoke explants are the most sensitive to agrobacteria on 4-5 h of in vitro culturing and this time corresponds to the certain period of G1-stage of the cell cycle. We have also estimated that this period is characterized by the increase of binding of acridine orange by nuclear chromatin and increase in activity of RNA-polymerase I and II. Inoculation of explants with agrobacteria in this period was the most optimal for transformation and crown gall induction. We estimated that at four - hour clinorotation of explants the intensity of acridine orange binding to nuclei was considerably lower than on 4h in the control. At one-day clinorotation of potato tubers, a considerable increase in template accessibility of chromatin and in activity of RNA-polymerase I and II occurred. These results may serve as an evidence for the ability of plant dormant tissues to respond to microgravity. Another demonstration of dormant tissue response to changed gravity we obtained when investigating pathogenesis-related proteins (PR-proteins). PR-proteins were subjected to nondenaturing PAGE.and we have not found any effect of microgravity on PR-proteins of potato explants with normal or tumorous growth. We may suggest that such response derives from the common effects of two stress factors - wounding and changed

  19. X-radiation-induced transformation in a C3H mouse embryo-derived cell line

    International Nuclear Information System (INIS)

    Terzaghi, M.; Little, J.B.

    1976-01-01

    Reproducible x-ray-induced oncogenic transformation has been demonstrated in an established cell line of mouse embryo fibroblasts. Cells derived from transformed foci formed malignant tumors when injected into syngeneic hosts. An exponential increase in the number of transformants per viable cell occurred with doses of up to 400 rads of x-radiation. The transformation frequency in exponentially growing cultures remained constant at 2.3 x 10 -3 following doses of 400 to 1500 rads. There was little change in survival following x-ray doses up to 300 rads. Doses greater than 300 rads were associated with an exponential decline in survival; the D 0 for the survival curve was 175 rads. Transformation frequency varied with changes in the number of viable cells seeded per dish. There was about a 10-fold decline in the transformation frequency when the number of cells was increased from 400 to 1000 viable cells/100-mm Petri dish. Below this density range there was little change in transformation frequency. The presence of lethally preirradiated cells was not associated with an enhancement of transformation in irradiated cells or with the induction of transformation in unirradiated cell cultures. Amphotericin B (Fungizone) inhibited the appearance of transformants when added to the culture medium within 2 to 3 weeks after initiation of the experiment

  20. Human cell transformation in the study of sunlight-induced cancers in the skin of man

    International Nuclear Information System (INIS)

    Sutherland, B.M.; Bennett, P.V.

    1988-01-01

    Human cell transformation provides a powerful approach to understanding - at the cellular and molecular levels - induction of cancers in the skin of man. A principal approach to this problem is the direct transformation of human skin cells by exposure to ultraviolet and/or near-UV radiation. The frequency of human cells transformed to anchorage independence increases with radiation exposure; the relative transforming efficiencies of different wavelengths implies that direct absorption by nucleic acids is a primary initial event. Partial reversal of potential transforming lesions by photoreactivation suggests that pyrimidine dimers, as well as other lesions, are important in UV transformation of human cells. Human cells can also be transformed by transfection with cloned oncogenes, or with DNAs from tumors or tumor cell lines. Cells treated by the transfection procedure (but without DNA) or cells transfected with DNAs from normal mammalian cells or tissues show only background levels of transformation. Human cells can be transformed to anchorage-independent growth by DNAs ineffective in transformation of NIH 3T3 cells (including most human skin cancers), permitting the analysis of oncogenic molecular changes even in tumor DNAs difficult or impossible to analyze in rodent cell systems. 29 refs.; 4 figs.; 1 table

  1. Alpha-particles induce preneoplastic transformation of rat tracheal epithelial cells in culture

    International Nuclear Information System (INIS)

    Thomassen, D.G.; Seiler, F.A.; Shyr, L.-J.; Griffith, W.C.

    1990-01-01

    To characterize the potential role of high-l.e.t. radiation in respiratory carcinogenesis, the cytotoxic and transforming potency of 5.5 MeV α-particles from electroplated sources of 238 Pu were determined using primary cultures of rat tracheal epithelial cells. RBE for cell killing by α-particles versus X-rays varied with dose, and ranged between 4 and 1.5 for α doses in the range 0.2-4 Gy. At equally toxic doses (relative survival 0.18-0.2), all three agents induced similar frequencies of preneoplastic transformation. For preneoplastic transformation induced by doses of α- and X-radiations giving 80 per cent toxicity, an α RBE of 2.4 was derived. The similar RBEs for cell killing and for preneoplastic transformation suggest an association between the type or degree of radiation-induced damage responsible for both cell killing and cell transformation. (author)

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

    International Nuclear Information System (INIS)

    Isom, H.C.; Mummaw, J.; Kreider, J.W.

    1983-01-01

    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

  3. Two-dimensional electrophoretic analysis of transformation-sensitive polypeptides during chemically, spontaneously, and oncogene-induced transformation of rat liver epithelial cells

    DEFF Research Database (Denmark)

    Wirth, P J; Luo, L D; Fujimoto, Y

    1992-01-01

    ; AFB), spontaneously, and oncogene (v-Ha-ras, v-raf, and v-myc/v-raf)-induced transformation of RLE cells. Two-dimensional mapping of [35S]methionine-labeled whole cell lysate, cell-free in vitro translation products and [32P]orthophosphate-labeled polypeptides revealed subsets of polypeptides specific...... for each transformation modality. A search of the RLE protein database indicated the specific subcellular location for the majority of these transformation-sensitive proteins. Significant alterations in the expression of the extracellular matrix protein, fibronectin, as well as tropomyosin......- and intermediate filament-related polypeptides (vimentin, beta-tubulin, the cytokeratins, and actin) were observed among the various transformant cell lines. Immunoprecipitation and Western immunoblot analysis of tropomyosin expression in four individual AFB-, as well as four spontaneously induced, and each...

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

    International Nuclear Information System (INIS)

    Nairn, R.S.; Humphrey, R.M.; Adair, G.M.

    1988-01-01

    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)

  5. Development of Toroidal Core Transformers

    Energy Technology Data Exchange (ETDEWEB)

    de Leon, Francisco [New York Univ. (NYU), Brooklyn, NY (United States). Dept. of Electrical and Computer Engineering

    2014-08-01

    The original objective of this project was to design, build and test a few prototypes of single-phase dry-type distribution transformers of 25 kVA, 2.4 kV primary to 120 V transformers using cores made of a continuous steel strip shaped like a doughnut (toroid). At different points during the development of the project, the scope was enhanced to include the more practical case of a 25 kVA transformer for a 13.8 kV primary system voltage. Later, the scope was further expanded to design and build a 50 kVA unit to transformer voltage from 7.62 kV to 2x120 V. This is a common transformer used by Con Edison of New York and they are willing to test it in the field. The project officially started in September 2009 and ended in May 2014. The progress was reported periodically to DOE in eighteen quarterly reports. A Continuation Application was submitted to DOE in June 2010. In May 2011 we have requested a non-cost extension of the project. In December 2011, the Statement of Project Objectives (SOPO) was updated to reflect the real conditions and situation of the project as of 2011. A second Continuation Application was made and funding was approved in 2013 by DOE and the end date was extended to May 2014. The technical challenges that were overcome in this project include: the development of the technology to pass the impulse tests, derive a model for the thermal performance, produce a sound mechanical design, and estimate the inrush current. However, the greatest challenge that we faced during the development of the project was the complications of procuring the necessary parts and materials to build the transformers. The actual manufacturing process is relatively fast, but getting all parts together is a very lengthy process. The main products of this project are two prototypes of toroidal distribution transformers of 7.62 kV (to be used in a 13.8 kV system) to 2x120 V secondary (standard utilization voltage); one is rated at 25 kVA and the other at 50 kVA. The 25 k

  6. Neutron-energy-dependent cell survival and oncogenic transformation.

    Science.gov (United States)

    Miller, R C; Marino, S A; Martin, S G; Komatsu, K; Geard, C R; Brenner, D J; Hall, E J

    1999-12-01

    Both cell lethality and neoplastic transformation were assessed for C3H10T1/2 cells exposed to neutrons with energies from 0.040 to 13.7 MeV. Monoenergetic neutrons with energies from 0.23 to 13.7 MeV and two neutron energy spectra with average energies of 0.040 and 0.070 MeV were produced with a Van de Graaff accelerator at the Radiological Research Accelerator Facility (RARAF) in the Center for Radiological Research of Columbia University. For determination of relative biological effectiveness (RBE), cells were exposed to 250 kVp X rays. With exposures to 250 kVp X rays, both cell survival and radiation-induced oncogenic transformation were curvilinear. Irradiation of cells with neutrons at all energies resulted in linear responses as a function of dose for both biological endpoints. Results indicate a complex relationship between RBEm and neutron energy. For both survival and transformation, RBEm was greatest for cells exposed to 0.35 MeV neutrons. RBEm was significantly less at energies above or below 0.35 MeV. These results are consistent with microdosimetric expectation. These results are also compatible with current assessments of neutron radiation weighting factors for radiation protection purposes. Based on calculations of dose-averaged LET, 0.35 MeV neutrons have the greatest LET and therefore would be expected to be more biologically effective than neutrons of greater or lesser energies.

  7. Misoprostol-induced radioprotection of Syrian hamster embryo cells in utero from cell death and oncogenic transformation

    International Nuclear Information System (INIS)

    Miller, R.C.; LaNasa, P.; Hanson, W.R.

    1994-01-01

    Misoprostol, a PGE analog, is an effective radioprotector of murine intestine and hematopoietic and hair cell renewal systems. The radioprotective nature of misoprostol was extended to examine its ability to influence clonogenic cell survival and induction of oncogenic transformation in Syrian hamster embryo cells exposed to X rays in utero and assayed in vitro. Hamsters in their 12th day of pregnancy were injected subcutaneously with misoprostal, and 2 h later the pregnant hamsters were exposed to graded doses of X rays. Immediately after irradiation, hamsters were euthanized and embryonic tissue was explanted into culture dishes containing complete growth medium. After a 2-week incubation period, clongenic cell survival and morphologically transformed foci were determined. Survival of misoprostol-treated SHE cells was increased and yielded a dose reduction factor of 1.5 compared to SHE cells treated with X rays alone. In contrast, radiation-induced oncogenic transformation of misoprostol-treated cells was reduced by a factor of 20 compared to cells treated with X rays alone. These studies suggest that misoprostol not only protects normal tissues in vivo from acute radiation injury, but also protects cells, to a large extent, from injury leading to transforming events. 26 refs., 6 figs., 2 tabs

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

    International Nuclear Information System (INIS)

    Leibhard, S.; Smida, J.

    1996-01-01

    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.) [de

  9. Fourier analysis of the cell shape of paired human urothelial cell lines of the same origin but of different grades of transformation.

    Science.gov (United States)

    Ostrowski, K; Dziedzic-Goclawska, A; Strojny, P; Grzesik, W; Kieler, J; Christensen, B; Mareel, M

    1986-01-01

    The rationale of the present investigation is the observations made by many authors of changes in the molecular structure of the cell surface during the multistep process of malignant transformation. These changes may influence cell-matrix and cell-cell interactions and thereby cause changes in cell adhesiveness and cell shape. The aim of the present work was to investigate whether the development of various grades of transformation in vivo and in vitro of human urothelial cells is accompanied by significant changes in cell shape as measured by Fourier analysis. The following transformation grades (TGr) have been defined (Christensen et al. 1984; Kieler 1984): TGr I = nonmalignant, mortal cell lines that grow independently of fibroblasts and have a prolonged life span. TGr II = nonmalignant cell lines with an infinite life span. TGr III = malignant and immortal cell lines that grow invasively in co-cultures with embryonic chick heart fragments and possess tumorigenic properties after s.c. injection into nude mice. Comparisons of 4 pairs of cell lines were performed; each pair was of the same origin. Two pairs--each including a TGr I cell line (Hu 961b and Hu 1703S) compared to a TGr III cell line (Hu 961a or Hu 1703He)--were derived from two transitional cell carcinomas (TCC) containing a heterogeneous cell population. Two additional cell lines classified as TGr II (HCV-29 and Hu 609) were compared to two TGr III sublines (HCV-29T and Hu 609T, respectively) which arose by "spontaneous" transformation during propagation in vitro of the respective maternal TGr II-cell lines.(ABSTRACT TRUNCATED AT 250 WORDS)

  10. Suppression of transformed foci, induced by alpha radiation of C3H 10T1/2 cells, by untransformed cells

    International Nuclear Information System (INIS)

    Lloyd, E.L.; Gemmell, M.A.; Henning, C.B.

    1978-01-01

    The C3H 10T1/2 CL8 cell line obtained from a mouse embryo has been widely used for screening chemical carcinogens. Transformed foci are easily distinguishable in this system as crisscrossed, piled-up cells which stain more deeply than the surrounding untransformed cells. When these foci are ringcloned and subcultured, they have been shown to give rise to malignant tumors in C3H immunodepressed mice. Previous work showed that such malignant transformations, which occurred with a dose dependent frequency, could be induced by alpha particle irradiation. The present study, in turn, demonstrates that the expression of these transformations can be completely suppressed by co-cultivating the transformed cells with a large number of untransformed cells. The precise ratio of the number of untransformed cells to transformed cells to give complete suppression was found to vary in different experiments. Maximum effects were seen when a small number of transformed cells in low passage were used. These experiments may provide at least a partial explanation for the greatly increased frequency of transformations per cell irradiated in vitro, compared with the number of tumors observed after irradiation of the same number of cells in vivo. In addition, if conditions could be optimized whereby transformed foci could reproducibly be eliminated by the use of a known number of untransformed cells, this might have important applications in the prevention and treatment of certain human cancers

  11. Solution of two-dimensional diffusion equation for hexagonal cells by the finite Fourier transformation

    International Nuclear Information System (INIS)

    Kobayashi, Keisuke

    1975-01-01

    A method of solution is presented for a monoenergetic diffusion equation in two-dimensional hexagonal cells by a finite Fourier transformation. Up to the present, the solution by the finite Fourier transformation has been developed for x-y, r-z and x-y-z geometries, and the flux and current at the boundary are obtained in terms of Fourier series. It is shown here that the method can be applied to hexagonal cells and the expansion of boundary values in a Legendre polynomials gives numerically a higher accuracy than is obtained by a Fourier series. (orig.) [de

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

    International Nuclear Information System (INIS)

    van Duin, M.; Westerveld, A.; Hoeijmakers, J.H.

    1985-01-01

    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. Some characteristics of neoplastic cell transformation in transgenic mice.

    Science.gov (United States)

    Shvemberger, I N; Ermilov, A N

    1996-01-01

    The role of the expression of different cellular genes and viral oncogenes in malignant cell transformation is discussed. We pay special attention to the role of the genes for growth factors and their receptors and homeobox genes in oncogenesis. Based on both the literature and our own data, specific features of tumors developed in transgenic mice are discussed. All of these data are used to analyze current theories of multistep oncogenesis and the stochastic component in this process. We suggest that all known evidence about the mechanisms of oncogenesis be used in studying the problem at various structural and functional levels in an organism. The chapter shows that transgenic mice are a most suitable model for studying various aspects of malignant transformation from the molecular to the organismal and populational levels.

  14. Transformation of mouse embryo (C3H 10T1/2) cells by alpha particles

    International Nuclear Information System (INIS)

    Lloyd, E.L.; Gemmell, A.; Henning, C.B.; Gemmell, D.S.; Zabransky, B.J.

    1977-01-01

    Mammalian cells in culture (C3H mouse 10T1/2 cells) have been shown here for the first time to be transformed by alpha irradiation when cells were irradiated with 5.6 MeV alpha particles from a Tandem Van de Graaff machine. Malignant tumors were induced following inoculation of the transformed cells into syngeneic hosts. Unirradiated control cells injected at the same concentration have, so far, failed to produce tumors. The morphology of the transformed foci was remarkably similar to that obtained by x rays and chemicals but different from virally transformed cells. When the cells were seeded at low density in the exponential growth phase, the transformation frequency per surviving cell increased approximately as the cube of the dose and peaked at an alpha particle fluence between 1.5 and 2.5 x 10 7 alpha particles per cm 2 (205 to 342 rads). The frequency of the transformation was found to be greatly dependent on the number of cells per dish irradiated. Irradiation of larger numbers resulted in much lower frequencies of transformation. The maximum transformation frequency observed in nine separate experiments was 4 percent of the surviving cells. At doses greater than 200 rads the transformation frequency per surviving cell remained constant. The present results permit us to conclude that alpha irradiation may, indeed, be able to exert a direct effect on the genome of the cell to produce malignancy without any external immunological or hormonal influences

  15. Developing Global Transformational Leaders

    DEFF Research Database (Denmark)

    Ramsey, Jase R.; Rutti, Raina M.; Lorenz, Melanie P.

    2016-01-01

    Despite significant increases in training and development of global managers, little is known about the precursors of transformational leadership in Multilatinas. While prior cross-cultural literature suggests that being an autocratic leader is ideal in Multilatinas, using transformational...... leadership theory, we argue that global leaders of Multilatinas embrace a more humanistic approach to leadership because of the importance of relationships between leaders and their followers. Additionally, we argue that global leaders with high levels of cultural intelligence will have high levels...

  16. Radiation transformation in differentiated human cells in culture

    International Nuclear Information System (INIS)

    Mothersill, C.; Seymour, C.; Moriarty, M.; Malone, J.; Byrne, P.; Hennessy, T.

    1986-01-01

    A tissue culture technique is described for human thyroid tissue as an approach to studying mechanisms of human radiation carcinogenesis. Normal human tissue obtained from surgery is treated in one of two ways, depending upon size of specimen. Large pieces are completely digested in trypsin/ collagenase solution to a single cell suspension. Small pieces of tissue are plated as explants following partial digestion in trypsin/collagenase solution. Following irradiation of the primary differentiated monolayers (normally 10 days after plating), the development of transformed characteristics is monitored in the subsequent subcultures. A very high level of morphological and functional differentiation is apparent in the primary cultures. Over a period of approx. 6 months, the irradiated surviving cells continue to grow in culture, unlike the unirradiated controls which senesce after 2-3 subcultures. (UK)

  17. Effects of oxygen and misonidazole on cell transformation and cell killing in C3H 10T1/2 cells by X rays in vitro

    International Nuclear Information System (INIS)

    Borsa, J.; Sargent, M.D.; Einspenner, M.; Azzam, E.I.; Raaphorst, G.P.

    1984-01-01

    The effects of oxygen (air) and misonidazole on the transformation and killing of 10T1/2 cells by X rays were examined. The oxygen effect for the cell transformation end point was very similar to that for cell killing. Misonidazole enhanced both cell killing and cell transformation to a similar extent. The enhancement of both end points by misonidazole occurred only in the absence of oxygen during irradiation and was of lesser magnitude than that observed for oxygen. These results demonstrate that the radiation chemical processes leading to cell killing and cell transformation, respectively, are affected similarly by these two enhancers of radiation action. 22 references, 3 figures, 2 tables

  18. Solitary waves in morphogenesis: Determination fronts as strain-cued strain transformations among automatous cells

    Science.gov (United States)

    Cox, Brian N.; Landis, Chad M.

    2018-02-01

    We present a simple theory of a strain pulse propagating as a solitary wave through a continuous two-dimensional population of cells. A critical strain is assumed to trigger a strain transformation, while, simultaneously, cells move as automata to tend to restore a preferred cell density. We consider systems in which the strain transformation is a shape change, a burst of proliferation, or the commencement of growth (which changes the shape of the population sheet), and demonstrate isomorphism among these cases. Numerical and analytical solutions describe a strain pulse whose height does not depend on how the strain disturbance was first launched, or the rate at which the strain transformation is achieved, or the rate constant in the rule for the restorative cell motion. The strain pulse is therefore very stable, surviving the imposition of strong perturbations: it would serve well as a timing signal in development. The automatous wave formulation is simple, with few model parameters. A strong case exists for the presence of a strain pulse during amelogenesis. Quantitative analysis reveals a simple relationship between the velocity of the leading edge of the pulse in amelogenesis and the known speed of migration of ameloblast cells. This result and energy arguments support the depiction of wave motion as an automatous cell response to strain, rather than as a response to an elastic energy gradient. The theory may also contribute to understanding the determination front in somitogenesis, moving fronts of convergent-extension transformation, and mitotic wavefronts in the syncytial drosophila embryo.

  19. Cytological and oncogene alterations in radiation-transformed Syrian hamster embryo cells

    International Nuclear Information System (INIS)

    Trutschler, K.; Hieber, L.; Kellerer, A.M.

    1991-01-01

    Syrian hamster embryo (SHE) cells were neoplastically transformed by different types of ionizing radiation (γ-rays, α-particles or carbon ions). Transformed and tumor cell lines (derived from nude mice tumors) were analysed for alterations of the oncogenes c-Ha-ras and c-myc, i.e. RFLPs, gene amplifications, activation by point mutation, gene expression, and for cytological changes. In addition, the chromosome number and the numbers of micronuclei per cell have been determined in a series of cell lines. (author)

  20. PDZ domain-binding motif of human T-cell leukemia virus type 1 Tax oncoprotein augments the transforming activity in a rat fibroblast cell line

    International Nuclear Information System (INIS)

    Hirata, Akira; Higuchi, Masaya; Niinuma, Akiko; Ohashi, Minako; Fukushi, Masaya; Oie, Masayasu; Akiyama, Tetsu; Tanaka, Yuetsu; Gejyo, Fumitake; Fujii, Masahiro

    2004-01-01

    While human T-cell leukemia virus type 1 (HTLV-1) is associated with the development of adult T-cell leukemia (ATL), HTLV-2 has not been reported to be associated with such malignant leukemias. HTLV-1 Tax1 oncoprotein transforms a rat fibroblast cell line (Rat-1) to form multiple large colonies in soft agar, and this activity is much greater than that of HTLV-2 Tax2. We have demonstrated here that the increased number of transformed colonies induced by Tax1 relative to Tax2 was mediated by a PDZ domain-binding motif (PBM) in Tax1, which is absent in Tax2. Tax1 PBM mediated the interaction of Tax1 with the discs large (Dlg) tumor suppressor containing PDZ domains, and the interaction correlated well with the transforming activities of Tax1 and the mutants. Through this interaction, Tax1 altered the subcellular localization of Dlg from the detergent-soluble to the detergent-insoluble fraction in a fibroblast cell line as well as in HTLV-1-infected T-cell lines. These results suggest that the interaction of Tax1 with PDZ domain protein(s) is critically involved in the transforming activity of Tax1, the activity of which may be a crucial factor in malignant transformation of HTLV-1-infected cells in vivo

  1. GBM secretome induces transient transformation of human neural precursor cells.

    Science.gov (United States)

    Venugopal, Chitra; Wang, X Simon; Manoranjan, Branavan; McFarlane, Nicole; Nolte, Sara; Li, Meredith; Murty, Naresh; Siu, K W Michael; Singh, Sheila K

    2012-09-01

    Glioblastoma (GBM) is the most aggressive primary brain tumor in humans, with a uniformly poor prognosis. The tumor microenvironment is composed of both supportive cellular substrates and exogenous factors. We hypothesize that exogenous factors secreted by brain tumor initiating cells (BTICs) could predispose normal neural precursor cells (NPCs) to transformation. When NPCs are grown in GBM-conditioned media, and designated as "tumor-conditioned NPCs" (tcNPCs), they become highly proliferative and exhibit increased stem cell self-renewal, or the unique ability of stem cells to asymmetrically generate another stem cell and a daughter cell. tcNPCs also show an increased transcript level of stem cell markers such as CD133 and ALDH and growth factor receptors such as VEGFR1, VEGFR2, EGFR and PDGFRα. Media analysis by ELISA of GBM-conditioned media reveals an elevated secretion of growth factors such as EGF, VEGF and PDGF-AA when compared to normal neural stem cell-conditioned media. We also demonstrate that tcNPCs require prolonged or continuous exposure to the GBM secretome in vitro to retain GBM BTIC characteristics. Our in vivo studies reveal that tcNPCs are unable to form tumors, confirming that irreversible transformation events may require sustained or prolonged presence of the GBM secretome. Analysis of GBM-conditioned media by mass spectrometry reveals the presence of secreted proteins Chitinase-3-like 1 (CHI3L1) and H2A histone family member H2AX. Collectively, our data suggest that GBM-secreted factors are capable of transiently altering normal NPCs, although for retention of the transformed phenotype, sustained or prolonged secretome exposure or additional transformation events are likely necessary.

  2. 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

    2016-04-20

    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.

  3. In vitro properties and tumorigenicity of radiation-transformed clones of mouse 10T1/2 cells

    International Nuclear Information System (INIS)

    Otsu, Hiroshi; Yasukawa, Mieko; Terasima, Toyozo

    1983-01-01

    Nineteen radiation-induced and one spontaneously developed transformed foci were cloned from mouse 10T1/2 cells. Each clone was grown with normal 10T1/2 cells, and typing (types II and III) was carried out by making reference to the description of Reznikoff et al. Morphological characteristics of foci and their response to co-cultured normal counterparts are described. Some in vitro properties of the clones were examined and the relationship to each focus type is discussed. A reduced serum requirement of transformed clones was not recognized. Soft agar colonies were produced exclusively by type III clones. Tumorigenicity testing of the clones revealed that 93 % of type III clones were tumorigenic upon inoculation into syngeneic mice in an immunosuppressed condition. From these findings, it can be concluded that the tumorigenic potential of radiation-induced transformed cells can be predicted from the ability of the cells to form colonies in agar. (author)

  4. Role of DNA lesions and repair in the transformation of human cells

    International Nuclear Information System (INIS)

    Maher, V.M.; McCormick, J.J.

    1987-01-01

    Results of studies on the transformation of diploid human fibroblasts in culture into tumor-forming cells by exposure to chemical carcinogens or radiation indicate that such transformation is multi-stepped process that at least one step, acquisition of anchorage independence, occurs as a mutagenic event. Studies comparing normal-repairing human cells with DNA repair-deficient cells, such as those derived from cancer-prone xeroderma pigmentosum patients, indicate that excision repair in human fibroblasts is essentially an error-free process that the ability to excise potentially cytotoxic, mutagenic, or transforming lesions induced DNA by carcinogens determines their ultimate biological consequences. Cells deficient in excision repair are abnormally sensitive to these agents. Studies with cells treated at various times in the cell cycle show that there is a certain limited amount of time available for DNA repair between the initial exposure and the onset of the cellular event responsible for mutation induction and transformation to anchorage independence. The data suggest that DNA replication on a template containing unexcised lesions (photoproducts, adducts) is the critical event

  5. Rat embryo cells immortalized with transfected oncogenes are transformed by gamma irradiation.

    Science.gov (United States)

    Endlich, B; Salavati, R; Sullivan, T; Ling, C C

    1992-12-01

    Cesium-137 gamma rays were used to transform rat embryo cells (REC) which were first transfected with activated c-myc or c-Ha-ras oncogenes to produce immortal cell lines (REC:myc and REC:ras). When exposed to 6 Gy of 137Cs gamma rays, some cells became morphologically transformed with focus formation frequencies of approximately 3 x 10(-4) for REC:myc and approximately 1 x 10(-4) for REC:ras, respectively. Cells isolated from foci of gamma-ray-transformed REC:myc (REC:myc:gamma) formed anchorage-independent colonies and were tumorigenic in nude mice, but foci from gamma-ray-transformed REC:ras (REC:ras:gamma) did not exhibit either of these criteria of transformation. Similar to the results with gamma irradiation, we observed a sequence-dependent phenomenon when myc and ras were transfected into REC, one at a time. REC immortalized by ras transfection were not converted to a tumorigenic phenotype by secondary transfection with myc, but REC transfected with myc were very susceptible to transformation by subsequent ras transfection. This suggests that myc-immortalized cells are more permissive to transformation via secondary treatments. In sequentially transfected REC, myc expression was high whether it was transfected first or second, whereas ras expression was highest when the ras gene was transfected secondarily into myc-containing REC. Molecular analysis of REC:ras:gamma transformants showed no alterations in structure of the transfected ras or of the endogenous ras, myc, p53, or fos genes. The expression of ras and p53 was increased in some isolates of REC:ras:gamma, but myc and fos expression were not affected. Similarly, REC:myc:gamma transformants did not demonstrate rearrangement or amplification of the transfected or the endogenous myc genes, or of the potentially cooperating Ha-, Ki-, or N-ras genes. Northern hybridization analysis revealed increased expression of N-ras in two isolates, REC:myc:gamma 33 and gamma 41, but no alterations in the expression

  6. Arsenite induces cell transformation by reactive oxygen species, AKT, ERK1/2, and p70S6K1

    International Nuclear Information System (INIS)

    Carpenter, Richard L.; Jiang, Yue; Jing, Yi; He, Jun; Rojanasakul, Yon; Liu, Ling-Zhi; Jiang, Bing-Hua

    2011-01-01

    Highlights: ► Chronic exposure to arsenite induces cell proliferation and transformation. ► Arsenite-induced transformation increases ROS production and downstream signalings. ► Inhibition of ROS levels via catalase reduces arsenite-induced cell transformation. ► Interruption of AKT, ERK, or p70S6K1 inhibits arsenite-induced cell transformation. -- Abstract: Arsenic is naturally occurring element that exists in both organic and inorganic formulations. The inorganic form arsenite has a positive association with development of multiple cancer types. There are significant populations throughout the world with high exposure to arsenite via drinking water. Thus, human exposure to arsenic has become a significant public health problem. Recent evidence suggests that reactive oxygen species (ROS) mediate multiple changes to cell behavior after acute arsenic exposure, including activation of proliferative signaling and angiogenesis. However, the role of ROS in mediating cell transformation by chronic arsenic exposure is unknown. We found that cells chronically exposed to sodium arsenite increased proliferation and gained anchorage-independent growth. This cell transformation phenotype required constitutive activation of AKT, ERK1/2, mTOR, and p70S6K1. We also observed these cells constitutively produce ROS, which was required for the constitutive activation of AKT, ERK1/2, mTOR, and p70S6K1. Suppression of ROS levels by forced expression of catalase also reduced cell proliferation and anchorage-independent growth. These results indicate cell transformation induced by chronic arsenic exposure is mediated by increased cellular levels of ROS, which mediates activation of AKT, ERK1/2, and p70S6K1.

  7. 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

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

    International Nuclear Information System (INIS)

    Zhang, Zhuo; Pratheeshkumar, Poyil; Budhraja, Amit; Son, Young-Ok; Kim, Donghern; Shi, Xianglin

    2015-01-01

    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 2 O 2 ) and superoxide dismutase 2 (SOD2, antioxidant against O 2 ·− ) 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 report. The

  9. 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.

  10. Biochemical characterization of cells transformed via transfection by feline sarcoma virus proviral DNA.

    OpenAIRE

    Rosenberg, Z F; Sahagan, B G; Snyder, H W; Worley, M B; Essex, M; Haseltine, W A

    1981-01-01

    Murine fibroblasts transformed by transfection with DNA from mink cells infected with the Snyder-Theilen strain of feline sarcoma virus and subgroup B feline leukemia virus were analyzed for the presence of integrated proviral DNA and the expression of feline leukemia virus- and feline sarcoma virus-specific proteins. The transformed murine cells harbored at least one intact feline sarcoma virus provirus, but did not contain feline leukemia virus provirus. The transformed murine cells express...

  11. Malignant transformation of lichen planus hypertrophicus into squamous cell carcinoma

    Directory of Open Access Journals (Sweden)

    Aniket Bhagwat Bhole

    2016-01-01

    Full Text Available Neoplastic transformation of lichen planus (LP is reported, but it's a rare event. Squamous cell carcinoma (SCC complicating cutaneous LP has an incidence of 0.4%. Average age at the time of diagnosis of SCC in patients of LP is 58 years with a range of 29–78 years. We report an extremely rare case of 17-year-old female patient who developed SCC from lichen planus hypertrophicus (LPH, a variant of LP. Patient presented with LPH over the anterior aspect of both legs since the age of 7 years which is again a pediatric rarity. SCC developed over an anteromedial aspect of left ankle after 10 years when she came to us. Both the diagnoses were histopathologically confirmed. The patient was treated with complete excision of tumor and defect was closed with rotation flap. This report emphasizes that the long-standing hypertrophic form of LP seems to have a considerable propensity for malignant transformation, even in the juvenile age group. Hence, careful vigilance of a longstanding LPH is necessary to allow early detection of a developing SCC.

  12. Immunogenicity of guinea pig cells transformed in culture by chemical carcinogens.

    Science.gov (United States)

    Ohanian, S H; McCabe, R P; Evans, C H

    1981-12-01

    The immunogenicity of inbred strain 2/N guinea pig fibroblasts transformed to the malignant state in vitro by chemical carcinogens was evaluated with the use of a variety of in vivo and in vitro methods including delayed-type hypersensitivity skin and tumor transplantation tests and analysis of antibody production by immunofluorescence, complement fixation, and staphylococcal protein A binding tests. Neoplastic transformation was induced by direct treatment of cells in culture with benzo[a]pyrene, 3-methylcholanthrene, or N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) or by the host-mediated method by which fetuses were exposed to diethylnitrosamine or MNNG in vivo prior to cell culture. Rabbits and syngeneic guinea pigs were inoculated with unirradiated and X-irradiated clonally derived cells. Delayed hypersensitivity skin reactions to immunizing or other cells were equivalent in immunized or control guinea pigs, and no protection to tumor outgrowth from a challenge inoculum of immunizing cells was observed. Antibody activity induced in the sera of immunized guinea pigs was cross-reactive and removed by absorption with nontumorigenic cells. Rabbit antisera after absorption with fetal guinea pig cells were nonreactive with the specific immunizing or other culture cells. Chemical carcinogen-induced neoplastic transformation of guinea pig cells can, therefore, occur without formation of detectable, individually distinct cell surface tumor-specific neoantigens.

  13. Immunogenicity of guinea pig cells transformed in culture by chemical carcinogens

    International Nuclear Information System (INIS)

    Ohanian, S.H.; McCabe, R.P.; Evans, C.H.

    1981-01-01

    The immunogenicity of inbred strain 2/N guinea pig fibroblasts transformed to the malignant state in vitro by chemical carcinogens was evaluated with the use of a variety of in vivo and in vitro methods including delayed-type hypersensitivity skin and tumor transplantation tests and analysis of antibody production by immunofluorescence, complement fixation, and staphylococcal protein A binding tests. Neoplastic transformation was induced by direct treatment of cells in culture with benzo[a]pyrene, 3-methylcholanthrene, or N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) or by the host-mediated method by which fetuses were exposed to diethylnitrosamine or MNNG in vivo prior to cell culture. Rabbits and syngeneic guinea pigs were inoculated with unirradiated and X-irradiated clonally derived cells. Delayed hypersensitivity skin reactions to immunizing or other cells were equivalent in immunized or control guinea pigs, and no protection to tumor outgrowth from a challenge inoculum of immunizing cells was observed. Antibody activity induced in the sera of immunized guinea pigs was cross-reactive and removed by absorption with nontumorigenic cells. Rabbit anitsera after absorption with fetal guinea pig cells were nonreactive with the specific immunizing or other cultured cells. Chemical carcinogen-induced neoplastic transformation of guinea pig cells can, therefore, occur without formation of detectable, individually distinct cell surface tumor-specific neoantigens

  14. Static harmonization of dynamically harmonized Fourier transform ion cyclotron resonance cell.

    Science.gov (United States)

    Zhdanova, Ekaterina; Kostyukevich, Yury; Nikolaev, Eugene

    2017-08-01

    Static harmonization in the Fourier transform ion cyclotron resonance cell improves the resolving power of the cell and prevents dephasing of the ion cloud in the case of any trajectory of the charged particle, not necessarily axisymmetric cyclotron (as opposed to dynamic harmonization). We reveal that the Fourier transform ion cyclotron resonance cell with dynamic harmonization (paracell) is proved to be statically harmonized. The volume of the statically harmonized potential distribution increases with an increase in the number of trap segments.

  15. Circle Hough transform implementation for dots recognition in braille cells

    Science.gov (United States)

    Jacinto Gómez, Edwar; Montiel Ariza, Holman; Martínez Sarmiento, Fredy Hernán.

    2017-02-01

    This paper shows a technique based on CHT (Circle Hough Transform) to achieve the optical Braille recognition (OBR). Unlike other papers developed around the same topic, this one is made by using Hough Transform to process the recognition and transcription of Braille cells, proving CHT to be an appropriate technique to go over different non-systematics factors who can affect the process, as the paper type where the text to traduce is placed, some lightning factors, input image resolution and some flaws derived from the capture process, which is realized using a scanner. Tests are performed with a local database using text generated by visual nondisabled people and some transcripts by sightless people; all of this with the support of National Institute for Blind People (INCI for their Spanish acronym) placed in Colombia.

  16. Developing nurses' transformational leadership skills.

    Science.gov (United States)

    Fischer, Shelly Ann

    2017-08-16

    Healthcare is a complex area with significant potential for service improvement despite the effects of increasing economic and social pressures on the quality and safety of patient care. As the largest group of healthcare professionals in direct contact with patients, nurses are well positioned to contribute to improvements in healthcare services and to the development of new policies. To influence healthcare improvements and policies effectively, nurses require leadership skills. Historically, it was thought that only nurses in management roles required leadership skills; however, the ability to influence change is a requirement at all levels of clinical practice. Transformational leadership competencies provide nurses with the skills to contribute to improvements in the quality and safety of patient care, while enhancing their career satisfaction. This article examines how nurses can apply transformational leadership to their practice. It also informs nurses how to conduct an initial self-assessment of their leadership skills and to formulate a transformational leadership development plan.

  17. Problems in mechanistic theoretical models for cell transformation by ionizing radiation

    International Nuclear Information System (INIS)

    Chatterjee, Aloke; Holley, W.R.

    1992-01-01

    A mechanistic model based on yields of double strand breaks has been developed to determine the dose response curves for cell transformation frequencies. At its present stage the model is applicable to immortal cell lines and to various qualities (X-rays, Neon and Iron) of ionizing radiation. Presently, we have considered four types of processes which can lead to activation phenomena: (i) point mutation events on a regulatory segment of selected oncogenes, (ii) inactivation of suppressor genes, through point mutation, (iii) deletion of a suppressor gene by a single track, and (iv) deletion of a suppressor gene by two tracks. (author)

  18. Effect of 8-methoxypsoralen-plus ultraviolet light on cell-virus interaction: the transforming infection; effect of PUVA on the transformation of baby hamster kidney cells by polyma virus

    International Nuclear Information System (INIS)

    Morhenn, V.B.; Kaye, J.A.

    1979-01-01

    Pre-treatment of baby hamster kidney (BHK) cells with 8-methoxypsoralen (8-MOP) plus ultraviolet (UV) light enhances the frequency of their transformation by polyoma (Py) virus. Of the doses tested, 0.5 microgram/m1 8-MOP plus 0 . 3 J/cm2 UV-light results in maximal (30-fold) stimulation of viral transformation. 8-MOP alone does not affect viral transformation and UV-light alone causes only a slight increase in the transformation frequency. Thus the drug and light act synergistically in promoting the effect. Treatment of BHK cells with drug plus light without Py infection does not lead to a transformed morphology. A drug-light combination (0 . 01 microgram/m1 8-MOP plus 1 . 2 J/cm2 UV) that inhibits cellular DNA synthesis is 75% of control at 28 hr after treatment results in a 6-fold stimulation of the transformation frequency

  19. Characterization of transformation related genes in oral cancer cells.

    Science.gov (United States)

    Chang, D D; Park, N H; Denny, C T; Nelson, S F; Pe, M

    1998-04-16

    A cDNA representational difference analysis (cDNA-RDA) and an arrayed filter technique were used to characterize transformation-related genes in oral cancer. From an initial comparison of normal oral epithelial cells and a human papilloma virus (HPV)-immortalized oral epithelial cell line, we obtained 384 differentially expressed gene fragments and arrayed them on a filter. Two hundred and twelve redundant clones were identified by three rounds of back hybridization. Sequence analysis of the remaining clones revealed 99 unique clones corresponding to 69 genes. The expression of these transformation related gene fragments in three nontumorigenic HPV-immortalized oral epithelial cell lines and three oral cancer cell lines were simultaneously monitored using a cDNA array hybridization. Although there was a considerable cell line-to-cell line variability in the expression of these clones, a reliable prediction of their expression could be made from the cDNA array hybridization. Our study demonstrates the utility of combining cDNA-RDA and arrayed filters in high-throughput gene expression difference analysis. The differentially expressed genes identified in this study should be informative in studying oral epithelial cell carcinogenesis.

  20. Repair mechanisms in radiation-induced cell transformation

    International Nuclear Information System (INIS)

    Elkind, M.M.; Han, A.; Hill, C.K.; Buonaguro, F.

    1983-01-01

    Our data with both low- and high-LET radiations are qualitatively similar to results obtained in vivo. This is evident, for example, in the reductions in cell transformation for protracted exposures of γ-rays. The consistencies between our results with cells and the data of others with animals lend support to Gray's hypothesis that tumorigenesis is the net effect of a low probability inductive process, and a high probability killing process. An important prediction can be made when spontaneous frequency is appreciable (e.g., 43% in the case of reticulum cell sarcoma in RFM mice). For small doses, tumorigenesis would drop provided that: (a) the cells responsible for the spontaneous incidence are present at the time of exposure; and (b) the progenitor cells of the tumor are not resistant to cell killing

  1. The Development of Breakdown in Transformer Oil

    Directory of Open Access Journals (Sweden)

    Jozef Kudelcik

    2007-01-01

    Full Text Available The conditions under which breakdown of composite liquid - solid insulation can be occurred, e.g. in transformer, play an important role in designing of such insulation. The initial state of breakdown development is explained based on development of streamers in cavitations. The whole breakdown development in transformer oil is represented by RLC circuit and it depends on the parameters of outer circuit.

  2. Modulation of cellular phosphoprotein profiles in transformation and redifferentiation of murine and embryonic fibroblastic cells

    International Nuclear Information System (INIS)

    Chakrabarty, Subhas; Brattain, M.G.

    1985-01-01

    Cellular phosphoprotein profiles from normal mouse embryonic fibroblast AKR-2B cells were compared to those of their permanently, chemically transformed malignant counterparts AKR-MCA cells, and AKR-2B cells reversibly transformed by transforming growth factor (AKR-TGF). Similar 32 P-phosphorylation profiles were observed for both the AKR-TGF and AKR-MCA cells which were distinct from that of the normal AKR-2B cells. Dimethylformamide (DMF)-induced differentiation of the AKR-MCA cells resulted in restoration of the normal AKR-2B phosphorylation profile to the malignant AKR-MCA cells. (author)

  3. Achieving the sustainable development goals: transforming public ...

    African Journals Online (AJOL)

    Achieving the sustainable development goals: transforming public health ... PROMOTING ACCESS TO AFRICAN RESEARCH ... The conference focused on transforming public health education and practice in the context of South Africa.

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

    International Nuclear Information System (INIS)

    Silva, Patricio; Soto, Nicolás; Díaz, Jorge; Mendoza, Pablo; Díaz, Natalia; Quest, Andrew F.G.; Torres, Vicente A.

    2015-01-01

    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

  5. Transformation of Balb 3T3 cells exposed to a germicidal UV lamp and a sunlamp

    International Nuclear Information System (INIS)

    Withrow, T.J.; Lugo, M.H.; Dempsey, M.J.

    1980-01-01

    The effect of germicidal UV and sunlamp exposure on direct and simian virus-40 (SV-40) transformatioon of Balb 3T3 cells was studied. Transformation was determined by the ability of transformed cells to grow as clones in agar. Radiation from these lamps enhanced direct transformation, and enhanced viral transformation to approximately the same degree. Enhanced transformation was seen with exposures of light that caused no measurable cell killing, which suggests that the induction of new transformants is involved rather than the selection of pre-existing transformants. Induction is also suggested by post-irradiation growth kinetics experiments. (author)

  6. Commensal bacteria drive endogenous transformation and tumour stem cell marker expression through a bystander effect.

    Science.gov (United States)

    Wang, Xingmin; Yang, Yonghong; Huycke, Mark M

    2015-03-01

    Commensal bacteria and innate immunity play a major role in the development of colorectal cancer (CRC). We propose that selected commensals polarise colon macrophages to produce endogenous mutagens that initiate chromosomal instability (CIN), lead to expression of progenitor and tumour stem cell markers, and drive CRC through a bystander effect. Primary murine colon epithelial cells were repetitively exposed to Enterococcus faecalis-infected macrophages, or purified trans-4-hydroxy-2-nonenal (4-HNE)-an endogenous mutagen and spindle poison produced by macrophages. CIN, gene expression, growth as allografts in immunodeficient mice were examined for clones and expression of markers confirmed using interleukin (IL) 10 knockout mice colonised by E. faecalis. Primary colon epithelial cells exposed to polarised macrophages or 4-hydroxy-2-nonenal developed CIN and were transformed after 10 weekly treatments. In immunodeficient mice, 8 of 25 transformed clones grew as poorly differentiated carcinomas with 3 tumours invading skin and/or muscle. All tumours stained for cytokeratins confirming their epithelial cell origin. Gene expression profiling of clones showed alterations in 3 to 7 cancer driver genes per clone. Clones also strongly expressed stem/progenitor cell markers Ly6A and Ly6E. Although not differentially expressed in clones, murine allografts positively stained for the tumour stem cell marker doublecortin-like kinase 1. Doublecortin-like kinase 1 and Ly6A/E were expressed by epithelial cells in colon biopsies for areas of inflamed and dysplastic tissue from E. faecalis-colonised IL-10 knockout mice. These results validate a novel mechanism for CRC that involves endogenous CIN and cellular transformation arising through a microbiome-driven bystander effect. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  7. Exogenous Gene Integration for Microalgal Cell Transformation Using a Nanowire-Incorporated Microdevice.

    Science.gov (United States)

    Bae, Sunwoong; Park, Seunghye; Kim, Jung; Choi, Jong Seob; Kim, Kyung Hoon; Kwon, Donguk; Jin, EonSeon; Park, Inkyu; Kim, Do Hyun; Seo, Tae Seok

    2015-12-16

    Superior green algal cells showing high lipid production and rapid growth rate are considered as an alternative for the next generation green energy resources. To achieve the biomass based energy generation, transformed microalgae with superlative properties should be developed through genetic engineering. Contrary to the normal cells, microalgae have rigid cell walls, so that target gene delivery into cells is challengeable. In this study, we report a ZnO nanowire-incorporated microdevice for a high throughput microalgal transformation. The proposed microdevice was equipped with not only a ZnO nanowire in the microchannel for gene delivery into cells but also a pneumatic polydimethylsiloxane (PDMS) microvalve to modulate the cellular attachment and detachment from the nanowire. As a model, hygromycin B resistance gene cassette (Hyg3) was functionalized on the hydrothermally grown ZnO nanowires through a disulfide bond and released into green algal cells, Chlamydomonas reinhardtii, by reductive cleavage. During Hyg3 gene delivery, a monolithic PDMS membrane was bent down, so that algal cells were pushed down toward ZnO nanowires. The supply of vacuum in the pneumatic line made the PDMS membrane bend up, enabling the gene delivered algal cells to be recovered from the outlet of the microchannel. We successfully confirmed Hyg3 gene integrated in microalgae by amplifying the inserted gene through polymerase chain reaction (PCR) and DNA sequencing. The efficiency of the gene delivery to algal cells using the ZnO nanowire-incorporated microdevice was 6.52 × 10(4)- and 9.66 × 10(4)-fold higher than that of a traditional glass bead beating and electroporation.

  8. Downregulation of proapoptotic Bim augments IL-2-independent T-cell transformation by human T-cell leukemia virus type-1 Tax

    International Nuclear Information System (INIS)

    Higuchi, Masaya; Takahashi, Masahiko; Tanaka, Yuetsu; Fujii, Masahiro

    2014-01-01

    Human T-cell leukemia virus type 1 (HTLV-1), an etiological agent of adult T-cell leukemia, immortalizes and transforms primary human T cells in vitro in both an interleukin (IL)-2-dependent and IL-2-independent manner. Expression of the HTLV-1 oncoprotein Tax transforms the growth of the mouse T-cell line CTLL-2 from being IL-2-dependent to IL-2-independent. Withdrawal of IL-2 from normal activated T cells induces apoptosis, which is mediated through the inducible expression of several proapoptotic proteins, including Bim. In this study, we found that Tax protects IL-2-depleted T cells against Bim-induced apoptosis. Withdrawal of IL-2 from CTLL-2 cells induced a prominent increase in the level of Bim protein in CTLL-2 cells, but not in Tax-transformed CTLL-2 cells. This inhibition of Bim in Tax-transformed CTLL-2 cells was mediated by two mechanisms: downregulation of Bim mRNA and posttranscriptional reduction of Bim protein. Transient expression of Tax in CTLL-2 cells also inhibited IL-2 depletion–induced expression of Bim, however, this decrease in Bim protein expression was not due to downregulation of Bim mRNA, thus indicating that Bim mRNA downregulation in Tax-transformed CTLL-2 occurs only after long-term expression of Tax. Transient expression of Tax in CTLL-2 cells also induced Erk activation, however, this was not involved in the reduction of Bim protein. Knockdown of Bim expression in CTLL-2 cells augmented Tax-induced IL-2-independent transformation. HTLV-1 infection of human T cells also reduced their levels of Bim protein, and restoring Bim expression in HTLV-1-infected cells reduced their proliferation by inducing apoptosis. Taken together, these results indicate that Tax-induced downregulation of Bim in HTLV-1-infected T cells promotes their IL-2-independent growth, thereby supporting the persistence of HTLV-1 infection in vivo

  9. Downregulation of proapoptotic Bim augments IL-2-independent T-cell transformation by human T-cell leukemia virus type-1 Tax.

    Science.gov (United States)

    Higuchi, Masaya; Takahashi, Masahiko; Tanaka, Yuetsu; Fujii, Masahiro

    2014-12-01

    Human T-cell leukemia virus type 1 (HTLV-1), an etiological agent of adult T-cell leukemia, immortalizes and transforms primary human T cells in vitro in both an interleukin (IL)-2-dependent and IL-2-independent manner. Expression of the HTLV-1 oncoprotein Tax transforms the growth of the mouse T-cell line CTLL-2 from being IL-2-dependent to IL-2-independent. Withdrawal of IL-2 from normal activated T cells induces apoptosis, which is mediated through the inducible expression of several proapoptotic proteins, including Bim. In this study, we found that Tax protects IL-2-depleted T cells against Bim-induced apoptosis. Withdrawal of IL-2 from CTLL-2 cells induced a prominent increase in the level of Bim protein in CTLL-2 cells, but not in Tax-transformed CTLL-2 cells. This inhibition of Bim in Tax-transformed CTLL-2 cells was mediated by two mechanisms: downregulation of Bim mRNA and posttranscriptional reduction of Bim protein. Transient expression of Tax in CTLL-2 cells also inhibited IL-2 depletion-induced expression of Bim, however, this decrease in Bim protein expression was not due to downregulation of Bim mRNA, thus indicating that Bim mRNA downregulation in Tax-transformed CTLL-2 occurs only after long-term expression of Tax. Transient expression of Tax in CTLL-2 cells also induced Erk activation, however, this was not involved in the reduction of Bim protein. Knockdown of Bim expression in CTLL-2 cells augmented Tax-induced IL-2-independent transformation. HTLV-1 infection of human T cells also reduced their levels of Bim protein, and restoring Bim expression in HTLV-1-infected cells reduced their proliferation by inducing apoptosis. Taken together, these results indicate that Tax-induced downregulation of Bim in HTLV-1-infected T cells promotes their IL-2-independent growth, thereby supporting the persistence of HTLV-1 infection in vivo. © 2014 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.

  10. A novel rat fibrosarcoma cell line from transformed bone marrow-derived mesenchymal stem cells with maintained in vitro and in vivo stemness properties

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Meng-Yu [Department of Cell Therapy, Institute for Cancer Research, Oslo University Hospital, Oslo (Norway); Nestvold, Janne, E-mail: j.m.nestvold@medisin.uio.no [Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo (Norway); Rekdal, Øystein [Department of Medical Biology, Faculty of Health Sciences, UiT The Arctic University of Norway, Tromsø (Norway); Kvalheim, Gunnar [Department of Cell Therapy, Institute for Cancer Research, Oslo University Hospital, Oslo (Norway); Fodstad, Øystein [Department of Tumor Biology, Institute for Cancer Research, Oslo University Hospital, Oslo (Norway)

    2017-03-15

    Increasing evidence suggests a possible relationship between mesenchymal stem cells (MSCs) and sarcoma. MSCs are hypothesized to be the cells initiating sarcomagenesis, and cancer stem cells (CSCs) sharing features of MSCs have been identified in sarcomas. Here, we report on the characteristics of a bone marrow-derived rat mesenchymal stem cell line that spontaneously transformed in long-term culture. The rat transformed mesenchymal stem cells (rTMSCs) produced soft-tissue fibrosarcomas in immunocompromised mice and immunocompetent rats. In vitro, the rTMSCs displayed increased proliferation capacity compared to the untransformed cell line. The transformed MSCs maintained the mesenchymal phenotype by expression of the stem cell marker CD 90 and the lack of hematopoietic and endothelial markers. Cytogenetic analysis detected trisomy 6 in the rTMSCs. Side population (SP) isolation and tumorsphere cultivation of the transformed cells confirmed the presence of CSCs among the rTMSCs. Importantly, the rTMSCs retained their differentiation capacity towards osteogenic and adipogenic lineages. This transformed MSC-based cell line may be valuable in examining the balance in a mixed cell population between cancer stem cell properties and the ability to differentiate to specific non-transformed cell populations. Moreover, it may also be a useful tool to evaluate the efficacy of novel targeted immunotherapies in vivo. - Highlights: • Spontaneously transformed rat MSCs (rTMSCs) share characteristics with normal MSCs. • rTMSCs possess a side population, enriched with tumorigenic cells. • rTMSCs model fibrosarcoma in vivo.

  11. A novel rat fibrosarcoma cell line from transformed bone marrow-derived mesenchymal stem cells with maintained in vitro and in vivo stemness properties

    International Nuclear Information System (INIS)

    Wang, Meng-Yu; Nestvold, Janne; Rekdal, Øystein; Kvalheim, Gunnar; Fodstad, Øystein

    2017-01-01

    Increasing evidence suggests a possible relationship between mesenchymal stem cells (MSCs) and sarcoma. MSCs are hypothesized to be the cells initiating sarcomagenesis, and cancer stem cells (CSCs) sharing features of MSCs have been identified in sarcomas. Here, we report on the characteristics of a bone marrow-derived rat mesenchymal stem cell line that spontaneously transformed in long-term culture. The rat transformed mesenchymal stem cells (rTMSCs) produced soft-tissue fibrosarcomas in immunocompromised mice and immunocompetent rats. In vitro, the rTMSCs displayed increased proliferation capacity compared to the untransformed cell line. The transformed MSCs maintained the mesenchymal phenotype by expression of the stem cell marker CD 90 and the lack of hematopoietic and endothelial markers. Cytogenetic analysis detected trisomy 6 in the rTMSCs. Side population (SP) isolation and tumorsphere cultivation of the transformed cells confirmed the presence of CSCs among the rTMSCs. Importantly, the rTMSCs retained their differentiation capacity towards osteogenic and adipogenic lineages. This transformed MSC-based cell line may be valuable in examining the balance in a mixed cell population between cancer stem cell properties and the ability to differentiate to specific non-transformed cell populations. Moreover, it may also be a useful tool to evaluate the efficacy of novel targeted immunotherapies in vivo. - Highlights: • Spontaneously transformed rat MSCs (rTMSCs) share characteristics with normal MSCs. • rTMSCs possess a side population, enriched with tumorigenic cells. • rTMSCs model fibrosarcoma in vivo.

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

    Science.gov (United States)

    Urani, C; Corvi, R; Callegaro, G; Stefanini, F M

    2013-09-01

    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 adoption of the assay partially depend on a fair degree of subjectivity in foci scoring. An objective evaluation may be obtained after separating foci from background monolayer in the digital image, and quantifying values of statistical descriptors which are selected to capture eye-scored morphological features. The aim of this study was to develop statistical descriptors to be applied to transformed foci of BALB/c 3T3, which cover foci size, multilayering and invasive cell growth into the background monolayer. Proposed descriptors were applied to a database of 407 foci images to explore the numerical features, and to illustrate open problems and potential solutions. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. 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

  14. Stability of the phenotypic reversion of x-ray transformed C3H/10T1/2 cells depends on cellular proliferation after subcultivation at low cell density

    International Nuclear Information System (INIS)

    Brouty-Boye, D.; Gresser, I.; Bandu, M.T.

    1982-01-01

    Reversion from the transformed to the non-transformed phenotype could be obtained by seeding X-ray transformed C3H/10T1/2 cells at low cell density. Cloned revertant cells of varying degrees of reversion were obtained depending on the time they were isolated after one subculture at low cell density. Most of the revertants isolated 7 and 10 days after seeding at very low cell density eventually returned to the transformed phenotype when passaged serially at high cell density. In contrast, 25-35% of the revertants isolated 17-20 days after seeding at low cell density maintained the non-transformed phenotype despite subsequent serial passages at high cell density. The finding that there was a direct relationship between the time during which transformed cells seeded at low cell density multiplied and the number of stable revertant clones obtained, suggests the possibility that reversion from the transformed to the non-transformed phenotype may be a multistep process. Revertant cells displayed a chromosomal pattern characteristic of the transformed cells rather than that of the parental non-transformed 10T1/2 cells. (author)

  15. Generation and characterization of p53 null transformed hepatic progenitor cells: oval cells give rise to hepatocellular carcinoma.

    Science.gov (United States)

    Dumble, Melissa L; Croager, Emma J; Yeoh, George C T; Quail, Elizabeth A

    2002-03-01

    Oval cells are bipotential liver stem cells able to differentiate into hepatocytes and bile duct epithelia. In normal adult liver oval cells are quiescent, existing in low numbers around the periportal region, and proliferate following severe, prolonged liver trauma. There is evidence implicating oval cells in the development of hepatocellular carcinoma, and hence the availability of an immortalized oval cell line would be invaluable for the study of liver cell lineage differentiation and carcinogenesis. A novel approach in the generation of cell lines is the use of the p53 knockout mouse. Absence of p53 allows a cell to cycle past the normal Hayflick limit, rendering it immortalized, although subsequent genetic alterations are thought necessary for transformation. p53 knockout mice were fed a choline-deficient, ethionine-supplemented diet, previously shown to increase oval cell numbers in wild-type mice. The oval cells were isolated by centrifugal elutriation and maintained in culture. Colonies of hepatic cells were isolated and characterized with respect to phenotype, growth characteristics and tumorigenicity. Analysis of gene expression by Northern blotting and immunocytochemistry suggests they are oval-like cells by virtue of albumin and transferrin expression, as well as the oval cell markers alpha fetoprotein, M(2)-pyruvate kinase and A6. Injection into athymic nude mice shows the cell lines are capable of forming tumors which phenotypically resemble hepatocellular carcinoma. Thus, the use of p53 null hepatic cells successfully generated immortalized and tumorigenic hepatic stem cell lines. The results presented support the idea that deleting p53 allows immortalization and contributes to the transformation of the oval-like cell lines. Further, the tumorigenic status of the cell lines is direct evidence for the participation of oval cells in the formation of hepatocellular carcinoma.

  16. 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.

  17. SV40-transformed human fibroblasts: evidence for cellular aging in pre-crisis cells.

    Science.gov (United States)

    Stein, G H

    1985-10-01

    Pre-crisis SV40-transformed human diploid fibroblast (HDF) cultures have a finite proliferative lifespan, but they do not enter a viable senescent state at end of lifespan. Little is known about either the mechanism for this finite lifespan in SV40-transformed HDF or its relationship to finite lifespan in normal HDF. Recently we proposed that in normal HDF the phenomena of finite lifespan and arrest in a viable senescent state depend on two separate processes: 1) an age-related decrease in the ability of the cells to recognize or respond to serum and/or other mitogens such that the cells become functionally mitogen-deprived at the end of lifespan; and 2) the ability of the cells to enter a viable, G1-arrested state whenever they experience mitogen deprivation. In this paper, data are presented that suggest that pre-crisis SV40-transformed HDF retain the first process described above, but lack the second process. It is shown that SV40-transformed HDF have a progressively decreasing ability to respond to serum as they age, but they continue to traverse the cell cycle at the end of lifespan. Concomitantly, the rate of cell death increases steadily toward the end of lifespan, thereby causing the total population to cease growing and ultimately to decline. Previous studies have shown that when SV40-transformed HDF are environmentally serum deprived, they likewise exhibit continued cell cycle traverse coupled with increased cell death. Thus, these results support the hypothesis that pre-crisis SV40-transformed HDF still undergo the same aging process as do normal HDF, but they end their lifespan in crisis rather than in the normal G1-arrested senescent state because they have lost their ability to enter a viable, G1-arrested state in response to mitogen deprivation.

  18. Location and cellular stages of NK cell development

    Science.gov (United States)

    Yu, Jianhua; Freud, Aharon G.; Caligiuri, Michael A

    2013-01-01

    The identification of distinct tissue-specific natural killer (NK) cell populations that apparently mature from local precursor populations has brought new insight into the diversity and developmental regulation of this important lymphoid subset. NK cells provide a necessary link between the early (innate) and late (adaptive) immune responses to infection. Gaining a better understanding of the processes that govern NK cell development should allow us to better harness NK cell functions in multiple clinical settings as well as to gain further insight into how these cells undergo malignant transformation. In this review, we summarize recent advances in understanding sites and cellular stages of NK cell development in humans and mice. PMID:24055329

  19. 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

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

    Science.gov (United States)

    Sripadi, Prabhakar; Shrestha, Bindesh; Easley, Rebecca L; Carpio, Lawrence; Kehn-Hall, Kylene; Chevalier, Sebastien; Mahieux, Renaud; Kashanchi, Fatah; Vertes, Akos

    2010-09-07

    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. 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. 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), expression-specific (Tax1 vs. Tax3) and cell-type-specific (T lymphocytes vs. kidney

  1. Enhancement of alpha particles-induced cell transformation by oxygen free radicals and tumor necrosis factor released from phagocytes

    International Nuclear Information System (INIS)

    Gong Yifen; Guo Renfeng; Zhu Maoxiang; Shou Jiang; Ge Guixiu; Yang Zhihua; Hieber, L.; Peters, K.; Schippel, C.

    1997-01-01

    To illustrate the role of several endogenous factors released from phagocytes under chronic inflammation in radiation-induced cancer. C 3 T 10 T 1/2 and SHE cells were used as targets, and 238 Pu alpha source was used in alpha irradiation. The enhancement of TF in alpha particles-induced cell transformation by PMA-stimulated human blood and zymosan-stimulated U-937 cells was studied using formation of transformed foci. Transformation frequency (TF) of C 3 H 10 T 1/2 cells exposed to alpha particles of 0.5 Gy increased 2.1 and 2.8 fold by PMA-and PMA-stimulated neutrophils, respectively. TF of irradiated SHE cells at a dose of 0.5 Gy increased 12 fold by the addition of the supernatant of macrophage-like U-937 cell line. It was shown that TF of irradiated SHE cells at above dose increased 8 fold by the supernatant treated with anti-TNF-α could be subcultured continuously in vitro. The cells at 40 th passage and two lines of monoclone cells have the ability to develop malignant tumors in nude mice. The overdose of free radicals and TNF-α released from neutrophils and macrophages have played an important role in low dose radiation-induced cancer

  2. Simian virus 40 small t antigen is not required for the maintenance of transformation but may act as a promoter (cocarcinogen) during establishment of transformation in resting rat cells.

    Science.gov (United States)

    Seif, R; Martin, R G

    1979-12-01

    Simian virus 40 deletion mutants affecting the 20,000-dalton (20K) t antigen and tsA mutants rendering the 90K T antigen temperature sensitive, as well as double mutants containing both mutations, induced host DNA synthesis in resting rat cells at the restrictive temperature. Nonetheless, the deletion mutants and double mutants did not induce transformation in resting cells even at the permissive temperature. On the other hand, the deletion mutants did induce full transformants when actively growing rat cells were infected; the transformants grew efficiently in agar and to high saturation densities on platic. The double mutants did not induce T-antigen-independent (temperature-insensitive) transformants which were shown previously to arise preferentially from resting cells. Thus, small t antigen was dispensable for the maintenance of the transformed phenotype in T-antigen-dependent rat transformants (transformants derived from growing cells) and may play a role in the establishment of T-antigen-independent transformants. We attempt to establish a parallel between transformation induced by chemical carcinogens and simian virus 40-induced transformation.

  3. Transformation assay in Bhas 42 cells: a model using initiated cells to study mechanisms of carcinogenesis and predict carcinogenic potential of chemicals.

    Science.gov (United States)

    Sasaki, Kiyoshi; Umeda, Makoto; Sakai, Ayako; Yamazaki, Shojiro; Tanaka, Noriho

    2015-01-01

    Transformation assays using cultured cells have been applied to the study of carcinogenesis. Although various cell systems exist, few cell types such as BALB/c 3T3 subclones and Syrian hamster embryo cells have been used to study chemically induced two-stage carcinogenesis. Bhas 42 cells were established as a clone by the transfection with the v-Ha-ras gene into mouse BALB/c 3T3 A31-1-1 cells and their subsequent selection based on their sensitivity to 12-O-tetradecanoylphorbol-13-acetate. Using Bhas 42 cells, transformed foci were induced by the treatment with nongenotoxic carcinogens, most of which act as tumor promoters. Therefore, Bhas 42 cells were considered to be a model of initiated cells. Subsequently, not only nongenotoxic carcinogens but also genotoxic carcinogens, most of which act as tumor initiators, were found to induce transformed foci by the modification of the protocol. Furthermore, transformation of Bhas 42 cells was induced by the transfection with genes of oncogenic potential. We interpret this high sensitivity of Bhas 42 cells to various types of carcinogenic stimuli to be related to the multistage model of carcinogenesis, as the transfection of v-Ha-ras gene further advances the parental BALB/c 3T3 A31-1-1 cells toward higher transforming potential. Thus, we propose that Bhas 42 cells are a novel and sensitive cell line for the analysis of carcinogenesis and can be used for the detection of not only carcinogenic substances but also gene alterations related to oncogenesis. This review will address characteristics of Bhas 42 cells, the transformation assay protocol, validation studies, and the various chemicals tested in this assay.

  4. 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.

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

    International Nuclear Information System (INIS)

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

    1978-01-01

    A line of 3T3 mouse cells lacking deoxythymidine kinase (dTK - ) was stably transformed to the dTK + phenotype after exposure to uv-irradiated equine herpesvirus type 1 (EHV-1). Biochemical transformants were isolated in a system selective for the dTK + phenotype (Eagle minimal essential medium containing 10 -4 M hypoxanthine, 6 x 10 -7 M aminopterin, and 2 x 10 -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 + 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

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

    International Nuclear Information System (INIS)

    Escudero-Lourdes, C.; Wu, T.; Camarillo, J.M.; Gandolfi, A.J.

    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

  7. Changes in cell surface structure by viral transformation studied by binding of lectins differing in sugar specificity.

    Science.gov (United States)

    Tsuda, M; Kurokawa, T; Takeuchi, M; Sugino, Y

    1975-10-01

    Changes in cell surface structure by viral transformation were studied by examining changes in the binding of various lectins differing in carbohydrate specificities. Binding of lectins was assayed directly using cells grown in coverslips. The following 125I-lectins were used: Concanavalin-A (specific for glucose and mannose), wheat germ agglutinin (specific for N-acetylglucosamine), castor bean agglutinin (specific for galactose), Wistaria floribunda agglutinin (specific for N-acetylgalactosamine), and soybean agglutinin (specific for N-acetyl-galactosamine). Cells for a clone, SS7, transformed by bovine adenovirus type-3, were found to bind 5 to 6 times more Wistaria floribunda agglutinin than the normal counterpart cells (clone C31, from C3H mouse kidney). In contrast, the binding of soybean agglutinin, which has a sugar specificity similar to Wistaria floribunda agglutinin, to normal and transformed cells was similar. The binding of wheat germ agglutinin and castor bean agglutinin, respectively, to normal and transformed cells was also similar. However, normal cells bound twice as much concanavalin-A as transformed cells. Only half as much Wistaria floribunda agglutinin was bound to transformed cells when they had been dispersed with EDTA. These changes in the number of lectin binding sites on transformation are thought to reflect alteration of the cell surface structure. The amount of lectins bound per cell decreased with increase in cell density, especially in the case of binding of Wistaria floribunda agglutinin to normal cells.

  8. Reverse Transcriptase-Containing Particles Induced in Rous Sarcoma Virus-Transformed Rat Cells by Arginine Deprivation

    Science.gov (United States)

    Kotler, Moshe; Weinberg, Eynat; Haspel, Osnat; Becker, Yechiel

    1972-01-01

    Incubation of rat cells transformed by Rous sarcoma virus (RSV) in an arginine-deficient medium resulted in accumulation of particles in the culture medium. Such particles did not appear when the transformed rat cells were incubated in a complete medium nor in the medium of primary rat cells which were incubated either in arginine-deficient or complete media. The particles which were released from the arginine-deprived transformed rat cells resemble C-type particles in their properties. These particles band in sucrose gradients at a density of 1.16 g/ml and contain 35S ribonucleic acid (RNA) molecules and a reverse transcriptase activity. Analysis of the cytoplasm of transformed and primary rat cells, deprived and undeprived of arginine, revealed the presence of reverse transcriptase-containing particles which banded in sucrose gradients at a density of 1.14 g/ml. These particles differed from the particles released into the medium by the arginine-deprived RSV-transformed rat cells. The deoxyribonucleic acid (DNA) molecules synthesized in vitro by the reverse transcriptase present in the particles isolated from the medium of arginine-deprived cells hybridized to RSV RNA, whereas the DNA synthesized by the cell-bound enzyme had no homology to RSV RNA. PMID:4116137

  9. Canine tracheal epithelial cells are more sensitive than rat tracheal epithelial cells to transforming growth factor beta induced growth inhibition

    International Nuclear Information System (INIS)

    Hubbs, A.F.; Hahn, F.F.; Kelly, G.; Thomassen, D.G.

    1988-01-01

    Transforming growth factor beta (TGFβ) markedly inhibited growth of canine tracheal epithelial (CTE) cells. Reduced responsiveness to TGFβ-induced growth inhibition accompanied neoplastic progression of these cells from primary to transformed to neoplastic. This was similar to the relationship between neoplastic progression and increased resistance to TGFβ-induced growth inhibition seen for rat tracheal epithelial (RTE) cells. The canine cells were more sensitive than rat cells to TGFβ-induced growth inhibition at all stages in the neoplastic process. (author)

  10. 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.

  11. A novel approach for in vitro studies applying electrical fields to cell cultures by transformer-like coupling.

    Science.gov (United States)

    Hess, R; Neubert, H; Seifert, A; Bierbaum, S; Hart, D A; Scharnweber, D

    2012-12-01

    The purpose of this study was to develop a new apparatus for in vitro studies applying low frequency electrical fields to cells without interfering side effects like biochemical reactions or magnetic fields which occur in currently available systems. We developed a non-invasive method by means of the principle of transformer-like coupling where the magnetic field is concentrated in a toroid and, therefore, does not affect the cell culture. Next to an extensive characterization of the electrical field parameters, initial cell culture studies have focused on examining the response of bone marrow-derived human mesenchymal stem cells (MSCs) to pulsed electrical fields. While no significant differences in the proliferation of human MSCs could be detected, significant increases in ALP activity as well as in gene expression of other osteogenic markers were observed. The results indicate that transformer-like coupled electrical fields can be used to influence osteogenic differentiation of human MSCs in vitro and can pose a useful tool in understanding the influence of electrical fields on the cellular and molecular level.

  12. The human T-lymphotropic virus type I tax gene can cooperate with the ras oncogene to induce neoplastic transformation of cells.

    Science.gov (United States)

    Pozzatti, R; Vogel, J; Jay, G

    1990-01-01

    Epidemiologic studies have linked infection by the human T-lymphotropic virus type I (HTLV-I) with the development of adult T-cell leukemia. The low penetrance of the virus and the long latency for disease manifestation are factors that obscure the role of HTLV-I infection in oncogenesis. We have used an in vitro transformation assay system to determine directly whether the HTLV-I tax gene has transformation potential. Transfection of the tax gene alone into early-passage rat embryo fibroblasts did not induce morphological alterations. However, cotransfection of tax with the selectable marker plasmid pRSVneo gave rise to G418-resistant colonies that could be established as immortalized cell lines. Cotransfection of tax with the ras oncogene into rat embryo fibroblasts gave rise to foci of transformed cells that were highly tumorigenic in nude mice. These data represent a direct demonstration of the oncogenic potential of the tax gene in nonlymphoid cells and establish HTLV-I as a transforming virus.

  13. Rat primary embryo fibroblast cells suppress transformation by the E6 and E7 genes of human papillomavirus type 16 in somatic hybrid cells.

    OpenAIRE

    Miyasaka, M; Takami, Y; Inoue, H; Hakura, A

    1991-01-01

    The E6 and E7 genes of human papillomavirus type 16 (HPV-16) transform established lines of rat cells but not rat cells in primary culture irrespective of the expression of the two genes. The reason for this difference between the susceptibilities of cell lines and primary cells was examined by using hybrid cells obtained by somatic cell fusion of rat cell lines transformed by the E6 and E7 genes of HPV-16 and freshly isolated rat embryo fibroblast cells. In these hybrid cells, transformed ph...

  14. 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...

  15. Cell-surface associated with transformation of human hepatocytes to the malignant phenotype

    International Nuclear Information System (INIS)

    Wilson, B.; Ozturk, M.; Takahashi, H.; Motte, P.; Kew, M.; Isselbacher, K.J.; Wands, J.R.

    1988-01-01

    Hepatocellular carcinoma is one of the leading causes of cancer death in the world. To understand the cellular changes associated with transformation of hepatocytes to the malignant state, the authors have made several libraries of monoclonal antibodies against the hepatocellular carcinoma cell line FOCUS and have found six antibodies (AF-20, SF-25, SF-31, SF-90, XF-4, and XF-8) that recognize antigens expressed at consistently higher levels on hepatoma cells. They have studied malignant and nontransformed liver tissue from the same individual by using direct 125 I-labeled antibody binding and immunoperoxidase staining techniques. For each of these antibodies, they found striking increases in antigen expression on the transformed tissues. These antigens were found to be expressed throughout the tumor and on distant metastases, with little, if any, expression on the nontransformed adjacent liver. These antibodies demonstrate that hepatic transformation may be accompanied by stereotyped and predictable antigenic changes. The uniformity of such antigenic changes suggests an association between these cell-surface alterations and the malignant transformation process

  16. Uncoupled regulation of fibronectin and collagen synthesis in Rous sarcoma virus transformed avian tendon cells

    International Nuclear Information System (INIS)

    Parry, G.; Soo, W.J.; Bissell, M.J.

    1979-01-01

    The regulation of fibronectin and procollagen synthesis has been investigated in normal and Rous sarcoma virus transformed primary avian tendon cells. These two proteins interact at the cell periphery and both are reportedly lost upon transformation. Whether their synthesis was coordinately regulated in Rous sarcoma virus-infected cells was thus examined. It was found that while the synthesis of both pro α 1 and pro α 2 peptides was reduced upon transformation, the synthesis of fibronectin was not altered. Nevertheless, long term radiolabeling demonstrated that fibronectin levels were reduced in transformed cells. It is concluded that the reduction in levels of these components at the surface is brought about by different mechanisms; collagen levels being regulated by procollagen synthesis and fibronectin levels by degradation and/or release into the culture medium. The possibility is discussed that fibronectin is lost from the cell periphery of primary avian tendon cells as a consequence of decreased levels of anchoring collagen molecules

  17. Generally Applicable Transformation Protocols for Fluorescent Nanodiamond Internalization into Cells.

    Science.gov (United States)

    Hemelaar, Simon R; van der Laan, Kiran J; Hinterding, Sophie R; Koot, Manon V; Ellermann, Else; Perona-Martinez, Felipe P; Roig, David; Hommelet, Severin; Novarina, Daniele; Takahashi, Hiroki; Chang, Michael; Schirhagl, Romana

    2017-07-19

    Fluorescent nanodiamonds (FNDs) are promising nanoprobes, owing to their stable and magnetosensitive fluorescence. Therefore they can probe properties as magnetic resonances, pressure, temperature or strain. The unprecedented sensitivity of diamond defects can detect the faint magnetic resonance of a single electron or even a few nuclear spins. However, these sensitivities are only achieved if the diamond probe is close to the molecules that need to be detected. In order to utilize its full potential for biological applications, the diamond particle has to enter the cell. Some model systems, like HeLa cells, readily ingest particles. However, most cells do not show this behavior. In this article we show for the first time generally applicable methods, which are able to transport fluorescent nanodiamonds into cells with a thick cell wall. Yeast cells, in particular Saccharomyces cerevisiae, are a favored model organism to study intracellular processes including aging on a cellular level. In order to introduce FNDs in these cells, we evaluated electrical transformation and conditions of chemical permeabilization for uptake efficiency and viability. 5% DMSO (dimethyl sulfoxide) in combination with optimized chemical transformation mix leads to high uptake efficiency in combination with low impact on cell biology. We have evaluated all steps in the procedure.

  18. Transformation in the Developing World: An Analysis of Colombia's Security Transformation

    National Research Council Canada - National Science Library

    Sprunk, Darren

    2004-01-01

    This thesis examines security force transformation issues germane to developing countries, in their attempt to counter emerging threats of international terrorism, insurgency, WMD proliferation and organized crime...

  19. Faculty Transformation in Curriculum Transformation: The Role of Faculty Development in Campus Internationalization

    Science.gov (United States)

    Niehaus, Elizabeth; Williams, Letitia

    2016-01-01

    Curriculum transformation is often cited as one of the key strategies for internationalizing higher education in the United States, and faculty members play a central role in this process. The purpose of the study we report here was to explore the potential for professional development initiatives to foster the transformation in perspectives…

  20. 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.

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

    International Nuclear Information System (INIS)

    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

  2. Development and verification of printed circuit board toroidal transformer model

    DEFF Research Database (Denmark)

    Pejtersen, Jens; Mønster, Jakob Døllner; Knott, Arnold

    2013-01-01

    An analytical model of an air core printed circuit board embedded toroidal transformer configuration is presented. The transformer has been developed for galvanic isolation of very high frequency switch-mode dc-dc power converter applications. The theoretical model is developed and verified...... by comparing calculated parameters with 3D finite element simulations and experimental measurement results. The developed transformer model shows good agreement with the simulated and measured results. The model can be used to predict the parameters of printed circuit board toroidal transformer configurations...

  3. Role of thyroid in x-ray-induced oncogenic transformation in cell culture

    International Nuclear Information System (INIS)

    Borek, C.

    1982-01-01

    This paper examines the role of thyroid hormones in x-ray-induced neoplastic transformation of C3H/10 T 1/2 cells. In addition, the delineation of the time when transformation is sensitive to T3, the dependence of transformation on T3 concentration, and the involvement of protein synthesis are studied. The results indicate that thyroid hormone plays a key role in the initiation of x-ray-induced neoplastic transformation and that induction of protein synthesis may mediate this response

  4. Methods for genetic transformation of filamentous fungi.

    Science.gov (United States)

    Li, Dandan; Tang, Yu; Lin, Jun; Cai, Weiwen

    2017-10-03

    Filamentous fungi have been of great interest because of their excellent ability as cell factories to manufacture useful products for human beings. The development of genetic transformation techniques is a precondition that enables scientists to target and modify genes efficiently and may reveal the function of target genes. The method to deliver foreign nucleic acid into cells is the sticking point for fungal genome modification. Up to date, there are some general methods of genetic transformation for fungi, including protoplast-mediated transformation, Agrobacterium-mediated transformation, electroporation, biolistic method and shock-wave-mediated transformation. This article reviews basic protocols and principles of these transformation methods, as well as their advantages and disadvantages.

  5. Development of stable marker-free nuclear transformation strategy ...

    African Journals Online (AJOL)

    Development of stable marker-free nuclear transformation strategy in the green microalga Chlorella vulgaris. ... into Chlorella by electroporation has very low stability and it is hard to screen the transformants without antibiotic marker genes.

  6. Excellence in clinical teaching: knowledge transformation and development required.

    Science.gov (United States)

    Irby, David M

    2014-08-01

    Clinical teachers in medicine face the daunting task of mastering the many domains of knowledge needed for practice and teaching. The breadth and complexity of this knowledge continue to increase, as does the difficulty of transforming the knowledge into concepts that are understandable to learners. Properly targeted faculty development has the potential to expedite the knowledge transformation process for clinical teachers. Based on my own research in clinical teaching and faculty development, as well as the work of others, I describe the unique forms of clinical teacher knowledge, the transformation of that knowledge for teaching purposes and implications for faculty development. The following forms of knowledge for clinical teaching in medicine need to be mastered and transformed: (i) knowledge of medicine and patients; (ii) knowledge of context; (iii) knowledge of pedagogy and learners, and (iv) knowledge integrated into teaching scripts. This knowledge is employed and conveyed through the parallel processes of clinical reasoning and clinical instructional reasoning. Faculty development can facilitate this knowledge transformation process by: (i) examining, deconstructing and practising new teaching scripts; (ii) focusing on foundational concepts; (iii) demonstrating knowledge-in-use, and (iv) creating a supportive organisational climate for clinical teaching. To become an excellent clinical teacher in medicine requires the transformation of multiple forms of knowledge for teaching purposes. These domains of knowledge allow clinical teachers to provide tailored instruction to learners at varying levels in the context of fast-paced and demanding clinical practice. Faculty development can facilitate this knowledge transformation process. © 2014 John Wiley & Sons Ltd.

  7. A flow-through hydrothermal cell for in situ neutron diffraction studies of phase transformations

    International Nuclear Information System (INIS)

    O'Neill, Brian; Tenailleau, Christophe; Nogthai, Yung; Studer, Andrew; Brugger, Joel; Pring, Allan

    2006-01-01

    A flow-through hydrothermal cell for the in situ neutron diffraction study of crystallisation and phase transitions has been developed. It can be used for kinetic studies on materials that exhibit structural transformations under hydrothermal conditions. It is specifically designed for use on the medium-resolution powder diffractometer (MRPD) at ANSTO, Lucas Heights, Sydney. But it is planned to adapt the design for the Polaris beamline at ISIS and the new high-intensity powder diffractometer (Wombat) at the new Australian reactor Opal. The cell will operate in a flow-through mode over the temperature range from 25-300 deg. C and up to pressures of 100 bar. The first results of a successful transformation of pentlandite (Fe,Ni) 9 S 8 to violarite (Fe,Ni) 3 S 4 under mild conditions (pH∼4) at 120 deg. C and 3 bar using in situ neutron diffraction measurements are presented

  8. GENETIC TRANSFORMATION AND ANALYSIS OF WHEAT TRANSGENIC CELL LINES BY IRAP-PCR

    Directory of Open Access Journals (Sweden)

    Bavol A. V.

    2013-12-01

    Full Text Available The transgenic wheat cell lines were obtained via biolistic transformation of the callus cultures initiated from the 3-day-old sterile seedling shoot apexes. The pAHC25 vector construction used for 14- and 28-day-old callus cultures transformation carried the selective phosphinothricin-N-acetyltransferase (bar gene and reporter ?-glucuronidase gene. The cell line selection was carried out on the media with phosphinothricin by means of graduated cell selection. The transgenic status of the obtained forms was proved by PCR-analysis. The presence of new relatively high molecular (more than 1 000 bp amplicons were found out for three transformed lines by means of IRAP PCRanalysis with the primers coding for long termainal repeats sequences of SIRE 1 retrotransposon. This fact may prove transposition of this mobile genetic element. The new DNA fragments were detected for three of the seven analyzed lines but for the control callus. It is possible to assume at induction of SIRE 1 transposition bis probably caused by the genomic stress of foreign DNA inserting or associated with the transformation process (mechanical wounding, cultivation on selective media.

  9. Lactose/whey utilization and ethanol production by transformed Saccharomyces cerevisiae cells.

    Science.gov (United States)

    Porro, D; Martegani, E; Ranzi, B M; Alberghina, L

    1992-04-05

    Strains of Saccharomyces cerevisiae transformed with a multicopy expression vector bearing both the Escherichia coli beta-galactosidase gene under the control of the upstream activating sequence of the GAL1-10 genes and the GAL4 activator gene release part of beta-galactosidase in the growth medium. This release is due to cell lysis of the older mother cells; the enzyme maintains its activity in buffered growth media. Fermentation studies with transformed yeast strains showed that the release of beta-galactosidase allowed an efficient growth on buffered media containing lactose as carbon source as well as on whey-based media. The transformed strains utilized up to 95% of the lactose and a high growth yield was obtained in rich media. High productions of ethanol were also observed in stationary phase after growth in lactose minimal media.

  10. 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

  11. Relationship between X-ray exposure and malignant transformation in C3H 10T1/2 cells

    International Nuclear Information System (INIS)

    Kennedy, A.R.; Fox, M.; Murphy, G.; Little, J.B.

    1980-01-01

    The appearance of transformed foci after x-irradiation of the C3H 10T1/2 line of murine cells requires extensive proliferation followed by prolonged incubation under conditions of confluence. When the progeny of irradiated cells are resuspended and plated to determine the number of potential transformed foci, the absolute yield is constant over a wide range of dilutions and is similar to that observed in cultures that have not been resuspended. In addition, for cells exposed to a given x-ray dose, the number of transformed foci per dish is independent of the number of irradiated cells. These observations suggest that few, if any, of the transformed clones occur as a direct consequence of the x-ray exposure and challenge the hypothesis that transformed foci are the clonal products of occasional cells that have experienced an x-ray-induced mutational change. Rather, it appears that at least two steps are involved. We suggest that exposure to x-rays results in a change, for example, the induction or expression of some cell function, in many or all of the cells and that this change is transmitted to the progeny of the surviving cells; a consequence of this change is an enhanced probability of the occurrence of a second step, transformation, when these cells are maintained under conditions of confluence

  12. In vitro transformation: interactions of chemical carcinogens and radiation

    International Nuclear Information System (INIS)

    DiPaolo, J.A.

    1976-01-01

    The development of reproducible quantitative in vitro procedures resulting in neoplastic transformation of mammalian cells has made possible the separation of events related to the process leading to transformation from secondary events that interfere with the early recognition of transformation. The use of chemical carcinogens on Syrian hamster cell strains results in a dose-response relation consistent with a Poisson distribution, indicating that the transformation phenomenon is inductive. In some circumstances, the joint action or interaction of chemical carcinogens with other agents results in an increased incidence of transformation. The pretreatment of Syrian hamster cells with ionizing radiation (250 R) or alkylating chemicals enhances the frequency of transformation on a cell or colony basis ordinarily obtained with known chemical carcinogens. Pretreatment with non-ionizing irradiation (uv, 254 nm) did not have a similar effect. The two types of irradiation and the alkylating agents reduced the cloning efficiency of the cells. X ray alone produced no transformation; the alkylating chemicals produced transformations infrequently, whereas uv produced a significant number of transformations. The number of transformations associated with uv is increased by pretreatment of the cells by x-irradiation. The enhancement of transformation by x-ray or x-ray-type agents appears to be independent of the type of second carcinogen used

  13. Transformation of membrane nanosurface of red blood cells under hemin action

    Science.gov (United States)

    Kozlova, Elena; Chernysh, Alexander; Moroz, Victor; Gudkova, Olga; Sergunova, Victoria; Kuzovlev, Artem

    2014-08-01

    Hemin is the product of hemoglobin oxidation. Some diseases may lead to a formation of hemin. The accumulation of hemin causes destruction of red blood cells (RBC) membranes. In this study the process of development of topological defects of RBC membranes within the size range from nanoscale to microscale levels is shown. The formation of the grain-like structures in the membrane (``grains'') with typical sizes of 120-200 nm was experimentally shown. The process of formation of ``grains'' was dependent on the hemin concentration and incubation time. The possible mechanism of membrane nanostructure alterations is proposed. The kinetic equations of formation and transformation of small and medium topological defects were analyzed. This research can be used to study the cell intoxication and analyze the action of various agents on RBC membranes.

  14. WRN-targeted therapy using inhibitors NSC 19630 and NSC 617145 induce apoptosis in HTLV-1-transformed adult T-cell leukemia cells

    Directory of Open Access Journals (Sweden)

    R. Moles

    2016-11-01

    Full Text Available Abstract Background Human T-cell leukemia virus type 1 (HTLV-1 infection is associated with adult T-cell leukemia/lymphoma (ATLL, a lymphoproliferative malignancy with a dismal prognosis and limited therapeutic options. Recent evidence shows that HTLV-1-transformed cells present defects in both DNA replication and DNA repair, suggesting that these cells might be particularly sensitive to treatment with a small helicase inhibitor. Because the “Werner syndrome ATP-dependent helicase” encoded by the WRN gene plays important roles in both cellular proliferation and DNA repair, we hypothesized that inhibition of WRN activity could be used as a new strategy to target ATLL cells. Methods Our analysis demonstrates an apoptotic effect induced by the WRN helicase inhibitor in HTLV-1-transformed cells in vitro and ATL-derived cell lines. Inhibition of cellular proliferation and induction of apoptosis were demonstrated with cell cycle analysis, XTT proliferation assay, clonogenic assay, annexin V staining, and measurement of mitochondrial transmembrane potential. Results Targeted inhibition of the WRN helicase induced cell cycle arrest and apoptosis in HTLV-1-transformed leukemia cells. Treatment with NSC 19630 (WRN inhibitor induces S-phase cell cycle arrest, disruption of the mitochondrial membrane potential, and decreased expression of anti-apoptotic factor Bcl-2. These events were associated with activation of caspase-3-dependent apoptosis in ATL cells. We identified some ATL cells, ATL-55T and LMY1, less sensitive to NSC 19630 but sensitive to another WRN inhibitor, NSC 617145. Conclusions WRN is essential for survival of ATL cells. Our studies suggest that targeting the WRN helicase with small inhibitors is a novel promising strategy to target HTLV-1-transformed ATL cells.

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

    International Nuclear Information System (INIS)

    Hung, Shih-Kai; Hung, Ling-Chien; Kuo, Cheng-Deng

    2010-01-01

    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

  16. Identification of p53 unbound to T-antigen in human cells transformed by simian virus 40 T-antigen.

    Science.gov (United States)

    O'Neill, F J; Hu, Y; Chen, T; Carney, H

    1997-02-27

    In several clones of SV40-transformed human cells, we investigated the relative amounts of large T-Antigen (T-Ag) and p53 proteins, both unbound and associated within complexes, with the goal of identifying changes associated with transformation and immortalization. Cells were transformed by wild type (wt) T-Ag, a functionally temperature sensitive T-Ag (tsA58) and other T-Ag variants. Western analysis showed that while most of the T-Ag was ultimately bound by p53, most of the p53 remained unbound to T-Ag. Unbound p53 remained in the supernatant after a T-Ag immunoprecipitation and p53 was present in two to fourfold excess of T-Ag. In one transformant there was five to tenfold more p53 than T-Ag. p53 was present in transformants in amounts at least 200-fold greater than in untransformed human cells. In wt and variant T-Ag transformants, including those generated with tsA58 T-Ag, large amounts of unbound p53 were present in both pre-crisis and immortal cells and when the cells were grown at permissive or non-permissive temperatures. We also found that in transformants produced by tsA58, an SV40/JCV chimeric T-Ag and other variants, T-Ag appeared to form a complex with p53 slowly perhaps because one or both proteins matured slowly. The presence in transformed human cells of large amounts of unbound p53 and in excess of T-Ag suggests that sequestration of p53 by T-Ag, resulting from complex formation, is required neither for morphological transformation nor immortalization of human cells. Rather, these results support the proposal that high levels of p53, the T-Ag/p53 complexes, or other biochemical event(s), lead to transformation and immortalization of human cells by T-Ag.

  17. Continuous activation of Nrf2 and its target antioxidant enzymes leads to arsenite-induced malignant transformation of human bronchial epithelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Xu [Department of Toxicology, School of Public Health, Jiangsu Key Laboratory of Preventive and Translational Medicine for Geriatric Diseases, Medical College of Soochow University, Suzhou, Jiangsu (China); Wang, Dapeng [Department of Toxicology, School of Public Health, Jiangsu Key Laboratory of Preventive and Translational Medicine for Geriatric Diseases, Medical College of Soochow University, Suzhou, Jiangsu (China); Department of Toxicology, School of Public Health, Guizhou Medical University, Guiyang, Guizhou (China); Ma, Yuan; Xu, Xiguo; Zhu, Zhen; Wang, Xiaojuan; Deng, Hanyi; Li, Chunchun; Chen, Min; Tong, Jian [Department of Toxicology, School of Public Health, Jiangsu Key Laboratory of Preventive and Translational Medicine for Geriatric Diseases, Medical College of Soochow University, Suzhou, Jiangsu (China); Yamanaka, Kenzo [Laboratory of Environmental Toxicology and Carcinogenesis, School of Pharmacy, Nihon University, Chiba (Japan); An, Yan, E-mail: dranyan@126.com [Department of Toxicology, School of Public Health, Jiangsu Key Laboratory of Preventive and Translational Medicine for Geriatric Diseases, Medical College of Soochow University, Suzhou, Jiangsu (China)

    2015-12-01

    Long-term exposure to arsenite leads to human lung cancer, but the underlying mechanisms of carcinogenesis remain obscure. The transcription factor of nuclear factor-erythroid-2 p45-related factor (Nrf2)-mediated antioxidant response represents a critical cellular defense mechanism and protection against various diseases. Paradoxically, emerging data suggest that the constitutive activation of Nrf2 is associated with cancer development, progression and chemotherapy resistance. However, the role of Nrf2 in the occurrence of cancer induced by long-term arsenite exposure remains to be fully understood. By establishing transformed human bronchial epithelial (HBE) cells via chronic low-dose arsenite treatment, we showed that, in acquiring this malignant phenotype, continuous low level of ROS and sustained enhancement of Nrf2 and its target antioxidant enzyme levels were observed in the later-stage of arsenite-induced cell transformation. The downregulation of Keap1 level may be responsible for the over-activation of Nrf2 and its target enzymes. To validate these observations, Nrf2 was knocked down in arsenite-transformed HBE cells by SiRNA transfection, and the levels of Nrf2 and its target antioxidant enzymes, ROS, cell proliferation, migration, and colony formation were determined following these treatments. Results showed that blocked Nrf2 expression significantly reduced Nrf2 and its target antioxidant enzyme levels, restored ROS levels, and eventually suppressed cell proliferation, migration, and colony formation of the transformed cells. In summary, the results of the study strongly suggested that the continuous activation of Nrf2 and its target antioxidant enzymes led to the over-depletion of intracellular ROS levels, which contributed to arsenite-induced HBE cell transformation. - Highlights: • Low level, long term arsenite exposure induces malignant transformation in vitro. • Long term arsenite exposure reduces ROS and MDA levels. • Long term arsenite

  18. Continuous activation of Nrf2 and its target antioxidant enzymes leads to arsenite-induced malignant transformation of human bronchial epithelial cells

    International Nuclear Information System (INIS)

    Yang, Xu; Wang, Dapeng; Ma, Yuan; Xu, Xiguo; Zhu, Zhen; Wang, Xiaojuan; Deng, Hanyi; Li, Chunchun; Chen, Min; Tong, Jian; Yamanaka, Kenzo; An, Yan

    2015-01-01

    Long-term exposure to arsenite leads to human lung cancer, but the underlying mechanisms of carcinogenesis remain obscure. The transcription factor of nuclear factor-erythroid-2 p45-related factor (Nrf2)-mediated antioxidant response represents a critical cellular defense mechanism and protection against various diseases. Paradoxically, emerging data suggest that the constitutive activation of Nrf2 is associated with cancer development, progression and chemotherapy resistance. However, the role of Nrf2 in the occurrence of cancer induced by long-term arsenite exposure remains to be fully understood. By establishing transformed human bronchial epithelial (HBE) cells via chronic low-dose arsenite treatment, we showed that, in acquiring this malignant phenotype, continuous low level of ROS and sustained enhancement of Nrf2 and its target antioxidant enzyme levels were observed in the later-stage of arsenite-induced cell transformation. The downregulation of Keap1 level may be responsible for the over-activation of Nrf2 and its target enzymes. To validate these observations, Nrf2 was knocked down in arsenite-transformed HBE cells by SiRNA transfection, and the levels of Nrf2 and its target antioxidant enzymes, ROS, cell proliferation, migration, and colony formation were determined following these treatments. Results showed that blocked Nrf2 expression significantly reduced Nrf2 and its target antioxidant enzyme levels, restored ROS levels, and eventually suppressed cell proliferation, migration, and colony formation of the transformed cells. In summary, the results of the study strongly suggested that the continuous activation of Nrf2 and its target antioxidant enzymes led to the over-depletion of intracellular ROS levels, which contributed to arsenite-induced HBE cell transformation. - Highlights: • Low level, long term arsenite exposure induces malignant transformation in vitro. • Long term arsenite exposure reduces ROS and MDA levels. • Long term arsenite

  19. Maize transformation technology development for commercial event generation

    Science.gov (United States)

    Que, Qiudeng; Elumalai, Sivamani; Li, Xianggan; Zhong, Heng; Nalapalli, Samson; Schweiner, Michael; Fei, Xiaoyin; Nuccio, Michael; Kelliher, Timothy; Gu, Weining; Chen, Zhongying; Chilton, Mary-Dell M.

    2014-01-01

    Maize is an important food and feed crop in many countries. It is also one of the most important target crops for the application of biotechnology. Currently, there are more biotech traits available on the market in maize than in any other crop. Generation of transgenic events is a crucial step in the development of biotech traits. For commercial applications, a high throughput transformation system producing a large number of high quality events in an elite genetic background is highly desirable. There has been tremendous progress in Agrobacterium-mediated maize transformation since the publication of the Ishida et al. (1996) paper and the technology has been widely adopted for transgenic event production by many labs around the world. We will review general efforts in establishing efficient maize transformation technologies useful for transgenic event production in trait research and development. The review will also discuss transformation systems used for generating commercial maize trait events currently on the market. As the number of traits is increasing steadily and two or more modes of action are used to control key pests, new tools are needed to efficiently transform vectors containing multiple trait genes. We will review general guidelines for assembling binary vectors for commercial transformation. Approaches to increase transformation efficiency and gene expression of large gene stack vectors will be discussed. Finally, recent studies of targeted genome modification and transgene insertion using different site-directed nuclease technologies will be reviewed. PMID:25140170

  20. Maize transformation technology development for commercial event generation.

    Science.gov (United States)

    Que, Qiudeng; Elumalai, Sivamani; Li, Xianggan; Zhong, Heng; Nalapalli, Samson; Schweiner, Michael; Fei, Xiaoyin; Nuccio, Michael; Kelliher, Timothy; Gu, Weining; Chen, Zhongying; Chilton, Mary-Dell M

    2014-01-01

    Maize is an important food and feed crop in many countries. It is also one of the most important target crops for the application of biotechnology. Currently, there are more biotech traits available on the market in maize than in any other crop. Generation of transgenic events is a crucial step in the development of biotech traits. For commercial applications, a high throughput transformation system producing a large number of high quality events in an elite genetic background is highly desirable. There has been tremendous progress in Agrobacterium-mediated maize transformation since the publication of the Ishida et al. (1996) paper and the technology has been widely adopted for transgenic event production by many labs around the world. We will review general efforts in establishing efficient maize transformation technologies useful for transgenic event production in trait research and development. The review will also discuss transformation systems used for generating commercial maize trait events currently on the market. As the number of traits is increasing steadily and two or more modes of action are used to control key pests, new tools are needed to efficiently transform vectors containing multiple trait genes. We will review general guidelines for assembling binary vectors for commercial transformation. Approaches to increase transformation efficiency and gene expression of large gene stack vectors will be discussed. Finally, recent studies of targeted genome modification and transgene insertion using different site-directed nuclease technologies will be reviewed.

  1. Development of transformations from business process models to implementations by reuse

    NARCIS (Netherlands)

    Dirgahayu, T.; Quartel, Dick; van Sinderen, Marten J.; Ferreira Pires, Luis; Hammoudi, S.

    2007-01-01

    This paper presents an approach for developing transformations from business process models to implementations that facilitates reuse. A transformation is developed as a composition of three smaller tasks: pattern recognition, pattern realization and activity transformation. The approach allows one

  2. Investigations of the functional states of dendritic cells under different conditioned microenvironments by Fourier transformed infrared spectroscopy.

    Science.gov (United States)

    Dong, Rong; Long, Jinhua; Xu, Xiaoli; Zhang, Chunlin; Wen, Zongyao; Li, Long; Yao, Weijuan; Zeng, Zhu

    2014-01-10

    Dendritic cells are potent and specialized antigen presenting cells, which play a crucial role in initiating and amplifying both the innate and adaptive immune responses. The dendritic cell-based vaccination against cancer has been clinically achieved promising successes. But there are still many challenges in its clinical application, especially for how to identify the functional states. The CD14+ monocytes were isolated from human peripheral blood after plastic adherence and purified to approximately 98% with cocktail immunomagnetic beads. The immature dendritic cells and mature dendritic cells were induced by traditional protocols. The resulting dendritic cells were cocultured with normal cells and cancer cells. The functional state of dendritic cells including immature dendritic cells (imDCs) and mature dendritic cells (mDCs) under different conditioned microenvironments were investigated by Fourier transformed infrared spectroscopy (FTIR) and molecular biological methods. The results of Fourier transformed infrared spectroscopy showed that the gene transcription activity and energy states of dendritic cells were specifically suppressed by tumor cells (P Fourier transformed infrared spectroscopy at given wave numbers were closely correlated with the expression levels of NF-κB (R2:0.69 and R2:0.81, respectively). Our results confirmed that the ratios of absorption intensities of Fourier transformed infrared spectroscopy at given wave numbers were positively correlated with the expression levels of NF-κB, suggesting that Fourier transformed infrared spectroscopy technology could be clinically applied to identify the functional states of dendritic cell when performing dendritic cell-based vaccination. It's significant for the simplification and standardization of dendritic cell-based vaccination clinical preparation protocols.

  3. Mobile phone base station radiation does not affect neoplastic transformation in BALB/3T3 cells.

    Science.gov (United States)

    Hirose, H; Suhara, T; Kaji, N; Sakuma, N; Sekijima, M; Nojima, T; Miyakoshi, J

    2008-01-01

    A large-scale in vitro study focusing on low-level radiofrequency (RF) fields from mobile radio base stations employing the International Mobile Telecommunication 2000 (IMT-2000) cellular system was conducted to test the hypothesis that modulated RF fields affect malignant transformation or other cellular stress responses. Our group previously reported that DNA strand breaks were not induced in human cells exposed to 2.1425 GHz Wideband Code Division Multiple Access (W-CDMA) radiation up to 800 mW/kg from mobile radio base stations employing the IMT-2000 cellular system. In the current study, BALB/3T3 cells were continuously exposed to 2.1425 GHz W-CDMA RF fields at specific absorption rates (SARs) of 80 and 800 mW/kg for 6 weeks and malignant cell transformation was assessed. In addition, 3-methylcholanthrene (MCA)-treated cells were exposed to RF fields in a similar fashion, to assess for effects on tumor promotion. Finally, the effect of RF fields on tumor co-promotion was assessed in BALB/3T3 cells initiated with MCA and co-exposed to 12-O-tetradecanoylphorbol-13-acetate (TPA). At the end of the incubation period, transformation dishes were fixed, stained with Giemsa, and scored for morphologically transformed foci. No significant differences in transformation frequency were observed between the test groups exposed to RF signals and the sham-exposed negative controls in the non-, MCA-, or MCA plus TPA-treated cells. Our studies found no evidence to support the hypothesis that RF fields may affect malignant transformation. Our results suggest that exposure to low-level RF radiation of up to 800 mW/kg does not induce cell transformation, which causes tumor formation. (c) 2007 Wiley-Liss, Inc.

  4. Promotion of TNF-α on malignant transformation of syrian hamster embryo cells irradiated with α-particles

    International Nuclear Information System (INIS)

    Zhu Maoxiang; Guo Renfeng; Yang Zhihua; GongYifen

    1999-01-01

    Objective: To illustrate the role of tumor necrosis factor-α (TNF-α) in radiation-induced cancer and regulatory mechanism of protein tyrosine phosphorylation. Methods: Taking Syrian hamster embryo cells exposed to 0.5 Gy α-particles as the target, an array of biological indicators such as cell growth curve, transformation frequency (TF), colony formation efficiency (CFE) and tumor formation in nude mice were observed, and the activities of protein tyrosine kinases and protein tyrosine phosphatases were measured. Results: Neither 0.5 Gy α-particle irradiation nor TNF-α alone could induce transformation of SHE cells morphologically, but the TF, CFE and levels of protein tyrosine phosphorylation were obviously increased in SHE cells treated with 600 U/ml TNF-α after exposure to 0.5 Gy α-particles, and malignant transformation was proved by tumorigenicity assays. Conclusion: TNF-α promotes significantly the transformation of SHE cells induced by α-particles, and protein tyrosine phosphorylation is probably involved in regulation of the process

  5. Development of 600 kV triple resonance pulse transformer.

    Science.gov (United States)

    Li, Mingjia; Zhang, Faqiang; Liang, Chuan; Xu, Zhou

    2015-06-01

    In this paper, a triple-resonance pulse transformer based on an air-core transformer is introduced. The voltage across the high-voltage winding of the air-core transformer is significantly less than the output voltage; instead, the full output voltage appears across the tuning inductor. The maximum ratio of peak load voltage to peak transformer voltage is 2.77 in theory. By analyzing pulse transformer's lossless circuit, the analytical expression for the output voltage and the characteristic equation of the triple-resonance circuit are presented. Design method for the triple-resonance pulse transformer (iterated simulation method) is presented, and a triple-resonance pulse transformer is developed based on the existing air-core transformer. The experimental results indicate that the maximum ratio of peak voltage across the load to peak voltage across the high-voltage winding of the air-core transformer is approximately 2.0 and the peak output voltage of the triple-resonance pulse transformer is approximately 600 kV.

  6. Dysregulated cellular functions and cell stress pathways provide critical cues for activating and targeting natural killer cells to transformed and infected cells.

    Science.gov (United States)

    Raulet, David H; Marcus, Assaf; Coscoy, Laurent

    2017-11-01

    Natural killer (NK) cells recognize and kill cancer cells and infected cells by engaging cell surface ligands that are induced preferentially or exclusively on these cells. These ligands are recognized by activating receptors on NK cells, such as NKG2D. In addition to activation by cell surface ligands, the acquisition of optimal effector activity by NK cells is driven in vivo by cytokines and other signals. This review addresses a developing theme in NK cell biology: that NK-activating ligands on cells, and the provision of cytokines and other signals that drive high effector function in NK cells, are driven by abnormalities that arise from transformation or the infected state. The pathways include genomic damage, which causes self DNA to be exposed in the cytosol of affected cells, where it activates the DNA sensor cGAS. The resulting signaling induces NKG2D ligands and also mobilizes NK cell activation. Other key pathways that regulate NKG2D ligands include PI-3 kinase activation, histone acetylation, and the integrated stress response. This review summarizes the roles of these pathways and their relevance in both viral infections and cancer. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  7. Chromosome alterations in the X-ray-induced transformants of cultured mouse cell line

    International Nuclear Information System (INIS)

    Kodama, Seiji; Komatsu, Kenshi; Okumura, Yutaka; Sasaki, M.S.

    1989-01-01

    Mouse m5S cells were subjected to soft X-ray irradiation. Twenty-four transformants were separated as indicators of focus formation. Two clones, cl.4103 and cl.6310, were chosen for the analysis of chromosome alterations in transformants. A parent strain, m5S/1M, served as the control. Anchorage independence (AG) was not detected in the control strain, irrespective of culture conditions and population doubling number (PDN). In the case of transformants, the frequency of AG was increased with increasing PDN for cl.4103, and was constant for cl.6310, irrespective of PDN. Karyotype of m5S/1M was 42, X, -Y, +der (6) t(6;13), t(8;8), +8, +15. In addition, -13, der(10) and -der(6)t(6;13), der(5), +mar occurred as karyotype alterations for cl.4103 and cl. 6310, respectively. The present experiment indicated that chromosome alterations secondary to primary alterations occur in a high frequency in the transforming process of X-ray irradiated cells, and that the secondary chromosome alterations result in selective proliferation of transformed clones. (Namekawa, K)

  8. Characteristics of radiation-induced neoplastic transformation in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Little, J.B.

    1986-01-01

    Data are presented to support the hypothesis that the initial step in the morphologic transformation of irradiated rodent (BALB/3T3) cells is a frequent cellular event involving a large fraction of the irradiated population. This process appears to involve DNA damage, but not to represent a targeted mutation in specific structural gene(s). Morphologic transformation and immortalization appear to be distinct steps in the overall process of transformation. In contradistinction to rodent cells, immortalization is a very rare event in human diploid cells which is induced at extremely low frequencies. The hypothesis is presented that immortality develops among clones of cells bearing stable chromosomal rearrangements which emerge during the proliferation of a population of radiation damaged cells.

  9. Molecular transformation, gene cloning, and gene expression systems for filamentous fungi

    Science.gov (United States)

    Gold, Scott E.; Duick, John W.; Redman, Regina S.; Rodriguez, Rusty J.

    2001-01-01

    This chapter discusses the molecular transformation, gene cloning, and gene expression systems for filamentous fungi. Molecular transformation involves the movement of discrete amounts of DNA into cells, the expression of genes on the transported DNA, and the sustainable replication of the transforming DNA. The ability to transform fungi is dependent on the stable replication and expression of genes located on the transforming DNA. Three phenomena observed in bacteria, that is, competence, plasmids, and restriction enzymes to facilitate cloning, were responsible for the development of molecular transformation in fungi. Initial transformation success with filamentous fungi, involving the complementation of auxotrophic mutants by exposure to sheared genomic DNA or RNA from wt isolates, occurred with low transformation efficiencies. In addition, it was difficult to retrieve complementing DNA fragments and isolate genes of interest. This prompted the development of transformation vectors and methods to increase efficiencies. The physiological studies performed with fungi indicated that the cell wall could be removed to generate protoplasts. It was evident that protoplasts could be transformed with significantly greater efficiencies than walled cells.

  10. Cell density dependence of transformation frequencies in C3H10T1/2 cells exposed to X-rays

    Energy Technology Data Exchange (ETDEWEB)

    Bettega, D; Calzolari, P; Ottolenghi, A; Lombardi, L T [Milan Univ. (Italy). Ist. di Fisica; Rimoldi, E [Milan Univ. (Italy). Ist. di Radiologia Veterinaria

    1989-12-01

    The effects of cell density on transformation frequencies were studied in C3H10T1/2 cells exposed to 0.5 and 7 Gy of 200 kVp X-rays. Initial cell density strongly influenced transformation frequency; this decreased by a factor of between 4 and 10 when the initial seeding density was changed from 50 to 2500 cells/10 cm diameter Petri dish. The data were fitted with two equations: (a) an allometric function represented on a log-log scale by a straight line and (b) a sigmoidal function with plateaux between 50 and 250 cells/dish and above 600. The two curves are compared and their probabilities discussed. Our data indicate that the region between 50 and 250 cells/dish would be the most suitable region for dose-effect measurements. A study of the growth curves at 0.5 and 8.5 Gy shows that cell growth rates are not influenced by initial cell density. (author).

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

    International Nuclear Information System (INIS)

    Okada, Fumito; Sato, Haruka; Omeri, Ahmad Khalid; Ono, Asami; Tokuyama, Kouhei; Ando, Yumiko; Matsumoto, Akira; Mori, Hiromu; Ogata, Masao; Kohno, Kazuhiro; Takano, Kuniko

    2015-01-01

    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.)

  12. 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.)

  13. Transformed human mesenchymal stem cells are more radiosensitive compared to their cells of origin in normoxia and in physiological hypoxia

    International Nuclear Information System (INIS)

    Worku, M.; Fersht, N.; Martindale, C.; Funes, J.M.; Shah, S.; Short, S.C.

    2013-01-01

    The full text of the publication follows. Purpose: The presence of hypoxic regions in tumours is associated with the recurrence of solid tumours after treatment with radiotherapy and thought to be an important element in defining the stem cell niche. We studied the effect of hypoxia on the response to radiation in sequentially transformed human mesenchymal stem cells (MSC) to investigate how the genetic events that lead to tumorigenicity influence the cellular response to radiation under hypoxic and normoxic conditions. Experimental Design: Human bone marrow derived SH2+, SH4+, Stro-1+ MSC were transformed step-wise by retroviral transfection of hTERT, HPV-16 E6 and E7, SV40 small T antigen and oncogenic H-ras. Cells were grown and irradiated with 0, 1 to 5 Gy, X-Ray at 20%, 5% and 1% oxygen tensions. Cytotoxicity, DNA double-strand break (DSB) repair and checkpoint signalling were compared between cells at three different stages of transformation and in different oxygen concentrations. Results: MSCs became more radiosensitive at each point during step-wise transformation, and this effect persisted when cells were irradiated in physiological hypoxia. Increased cytotoxicity of radiation was associated with increased residual DNA DSB at 24 post X-irradiation assessed by gamma-H2AX foci. Growth and irradiation in 1% but not 5% oxygen promoted increased radioresistance compared to growth in 20% oxygen but did not change the relative sensitivity of tumorigenic cells compared to parental cells. Activation of checkpoint signalling before and after single radiation doses is more marked in tumorigenic cells compared to parental lines, and is not altered when cells are irradiated and grown in hypoxic conditions. Conclusions: These data show that tumorigenic cells are more radiosensitive compared to non-tumorigenic parental cells in both normoxic and hypoxic conditions. 1% hypoxia promotes radioresistance in all cells. Checkpoint signalling is up-regulated in tumorigenic

  14. Methodologies to increase the transformation efficiencies and the range of bacteria that can be transformed.

    Science.gov (United States)

    Aune, Trond Erik Vee; Aachmann, Finn Lillelund

    2010-02-01

    Methods for transfer of exogenous DNA into cells are essential for genetics and molecular biology, and the lack of effective methods hampers research on many different species of bacteria which have shown to be particularly recalcitrant to transformation. This review presents the progress on the development of methods for artificial transformation of bacteria with emphasis on different methodologies and the range of bacteria that can be transformed. The methods' strengths and weaknesses are described.

  15. Sequence of activation of template biosyntheses in normal and transformed human cells after synchronization with a double thimidine block

    International Nuclear Information System (INIS)

    Alekseev, S.B.; Boikov, P.Ya.; Ebralidze, L.K.; Stepanova, L.G.

    1986-01-01

    The sequences of synthesis of DNA, RNA, and various groups of proteins in normal and transformed human fibroblasts was studied in the first mitotic cycle synchronization of the cells by a double thymidine block. Two peculiarities of the synthesis of acid-soluble histone and acid-insoluble proteins in the normal and transformed cells, were detected: (1) in normal fibroblasts the synthesis of the two groups of proteins is a minimum before DNA replication, and the greatest activity is achieved in the G 2 phase; in transformed cells protein synthesis is a maximum after the removal of the thymine block, while in the G 2 phase it is decreased; (2) in normal fibroblasts the synthesis of acid-insoluble proteins is a maximum before the maximum synthesis of DNA, and that of acid-soluble proteins is a maximum after the maximum of DNA synthesis. The opposite picture is observed in transformed cells. RNA synthesis in normal and transformed cells is activated at the end of the G 2 phase. In normal cells the synthesis of proteins is coupled with the activation of RNA synthesis, while in transformed cells protein synthesis is evidently transferred to the following mitotic cycle. Especially pronounced differences were detected in the expression of certain LMG proteins. Thus, in transformed cells the regulation of the coupling of the template syntheses is modified

  16. Malignant transformation potentials of human umbilical cord mesenchymal stem cells both spontaneously and via 3-methycholanthrene induction.

    Directory of Open Access Journals (Sweden)

    Qiuling Tang

    Full Text Available Human umbilical cord mesenchymal stem cells (HUMSCs are highly proliferative and can be induced to differentiate into advanced derivatives of all three germ layers. Thus, HUMSCs are considered to be a promising source for cell-targeted therapies and tissue engineering. However there are reports on spontaneous transformation of mesenchymal stem cells (MSCs derived from human bone marrows. The capacity for HUMSCs to undergo malignant transform spontaneously or via induction by chemical carcinogens is presently unknown. Therefore, we isolated HUMSCs from 10 donors and assessed their transformation potential either spontaneously or by treating them with 3-methycholanthrene (3-MCA, a DNA-damaging carcinogen. The malignant transformation of HUMSCs in vitro was evaluated by morphological changes, proliferation rates, ability to enter cell senescence, the telomerase activity, chromosomal abnormality, and the ability to form tumors in vivo. Our studies showed that HUMSCs from all 10 donors ultimately entered senescence and did not undergo spontaneous malignant transformation. However, HUMSCs from two of the 10 donors treated with 3-MCA displayed an increased proliferation rate, failed to enter senescence, and exhibited an altered cell morphology. When these cells (tHUMSCs were injected into immunodeficient mice, they gave rise to sarcoma-like or poorly differentiated tumors. Moreover, in contrast to HUMSCs, tHUMSCs showed a positive expression of human telomerase reverse transcriptase (hTERT and did not exhibit a shortening of the relative telomere length during the long-term culture in vitro. Our studies demonstrate that HUMSCs are not susceptible to spontaneous malignant transformation. However, the malignant transformation could be induced by chemical carcinogen 3-MCA.

  17. Malignant Transformation Potentials of Human Umbilical Cord Mesenchymal Stem Cells Both Spontaneously and via 3-Methycholanthrene Induction

    Science.gov (United States)

    Lai, Xiulan; Liu, Sizheng; Chen, Yezeng; Zheng, Zexin; Xie, Qingdong; Maldonado, Martin; Cai, Zhiwei; Qin, Shan; Ho, Guyu; Ma, Lian

    2013-01-01

    Human umbilical cord mesenchymal stem cells (HUMSCs) are highly proliferative and can be induced to differentiate into advanced derivatives of all three germ layers. Thus, HUMSCs are considered to be a promising source for cell-targeted therapies and tissue engineering. However there are reports on spontaneous transformation of mesenchymal stem cells (MSCs) derived from human bone marrows. The capacity for HUMSCs to undergo malignant transform spontaneously or via induction by chemical carcinogens is presently unknown. Therefore, we isolated HUMSCs from 10 donors and assessed their transformation potential either spontaneously or by treating them with 3-methycholanthrene (3-MCA), a DNA-damaging carcinogen. The malignant transformation of HUMSCs in vitro was evaluated by morphological changes, proliferation rates, ability to enter cell senescence, the telomerase activity, chromosomal abnormality, and the ability to form tumors in vivo. Our studies showed that HUMSCs from all 10 donors ultimately entered senescence and did not undergo spontaneous malignant transformation. However, HUMSCs from two of the 10 donors treated with 3-MCA displayed an increased proliferation rate, failed to enter senescence, and exhibited an altered cell morphology. When these cells (tHUMSCs) were injected into immunodeficient mice, they gave rise to sarcoma-like or poorly differentiated tumors. Moreover, in contrast to HUMSCs, tHUMSCs showed a positive expression of human telomerase reverse transcriptase (hTERT) and did not exhibit a shortening of the relative telomere length during the long-term culture in vitro. Our studies demonstrate that HUMSCs are not susceptible to spontaneous malignant transformation. However, the malignant transformation could be induced by chemical carcinogen 3-MCA. PMID:24339974

  18. Selective cytotoxicity of transformed cells but not normal cells by a sialoglycopeptide growth regulator in the presence of tumor necrosis factor

    Science.gov (United States)

    Woods, K. M.; Fattaey, H.; Johnson, T. C.; Chapes, S. K.; Spooner, B. S. (Principal Investigator)

    1994-01-01

    The tumor necrosis factor-alpha (TNF)-resistant, SV40-transformed, murine fibroblast cell lines, F5b and F5m, became sensitive to TNF-mediated cytolysis after treatment with a biologically active 18 kDa peptide fragment (SGP) derived from a 66-kDa parental cell surface sialoglycoprotein. Neither TNF nor the SGP alone exhibited cytotoxicity to the two SV40-transformed cell lines. However, Balb/c 3T3 cells, incubated with SGP alone or with SGP and TNF, were not killed. Therefore, SGP can selectively sensitize cells for TNF alpha-mediated cytotoxicity. This selective sensitization may be due to the previously documented ability of the SGP to selectively mediate cell cycle arrest.

  19. 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.

  20. Correspondence between quantum-optical transform and classical-optical transform explored by developing Dirac's symbolic method

    Science.gov (United States)

    Fan, Hong-yi; Hu, Li-yun

    2012-06-01

    By virtue of the new technique of performing integration over Dirac's ket-bra operators, we explore quantum optical version of classical optical transformations such as optical Fresnel transform, Hankel transform, fractional Fourier transform, Wigner transform, wavelet transform and Fresnel-Hadmard combinatorial transform etc. In this way one may gain benefit for developing classical optics theory from the research in quantum optics, or vice-versa. We cannot only find some new quantum mechanical unitary operators which correspond to the known optical transformations, deriving a new theorem for calculating quantum tomogram of density operators, but also can reveal some new classical optical transformations. For examples, we find the generalized Fresnel operator (GFO) to correspond to the generalized Fresnel transform (GFT) in classical optics. We derive GFO's normal product form and its canonical coherent state representation and find that GFO is the loyal representation of symplectic group multiplication rule. We show that GFT is just the transformation matrix element of GFO in the coordinate representation such that two successive GFTs is still a GFT. The ABCD rule of the Gaussian beam propagation is directly demonstrated in the context of quantum optics. Especially, the introduction of quantum mechanical entangled state representations opens up a new area in finding new classical optical transformations. The complex wavelet transform and the condition of mother wavelet are studied in the context of quantum optics too. Throughout our discussions, the coherent state, the entangled state representation of the two-mode squeezing operators and the technique of integration within an ordered product (IWOP) of operators are fully used. All these have confirmed Dirac's assertion: "...for a quantum dynamic system that has a classical analogue, unitary transformation in the quantum theory is the analogue of contact transformation in the classical theory".

  1. 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.

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

    International Nuclear Information System (INIS)

    Yokoo, Masako; Fujita, Ryosuke; Nakajima, Yumiko; Yoshimizu, Mamoru; Kasai, Hisae; Asano, Shin-ichiro; Bando, Hisanori

    2013-01-01

    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

  3. 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

  4. Transformation by Oncogenic Ras Expands the Early Genomic Response to Transforming Growth Factor β in Intestinal Epithelial Cells

    Directory of Open Access Journals (Sweden)

    Carl E. Allen

    2008-10-01

    Full Text Available A substantial body of evidence implicates TGFβ as a tumor promoter in epithelial cells that have become resistant to its tumor suppressor activity. To better understand early, genome-wide TGFβ responses in cells resistant to growth inhibition by TGFβ, we used microarray analysis in a well-defined cell culture system of sensitive and resistant intestinal epithelial cells. TGFβ-regulated gene expression in TGFβ-growth-sensitive, nontransformed rat intestinal epithelial cells (RIE-1 was compared to expression in TGFβ-growth-resistant RIE cells stably transformed by oncogenic Ras(12V. Treatment of RIE-1 cells with 2 ng/ml TGFβ1 for 1 hour increased the expression of eight gene sequences by 2.6-fold or more, whereas eight were down regulated 2.6-fold. In RIE-Ras(12V cells, 42 gene sequences were upregulated and only 3 were down-regulated. Comparison of RIE and RIE-Ras(12V identified 37 gene sequences as unique, Ras-dependent genomic targets of TGFβ1. TGFβ-regulation of connective tissue growth factor and vascular endothelial growth factor, two genes up-regulated in RIE-Ras cells and previously implicated in tumor promotion, was independently confirmed and further characterized by Northern analysis. Our data indicate that overexpression of oncogenic Ras in intestinal epithelial cells confers a significantly expanded repertoire of robust, early transcriptional responses to TGFβ via signaling pathways yet to be fully elucidated but including the canonical Raf-1/MAPK/Erk pathway. Loss of sensitivity to growth inhibition by TGFβ does not abrogate TGFβ signaling and actually expands the early transcriptional response to TGFβ1. Expression of some of these genes may confer to Ras-transformed cells characteristics favorable for tumor promotion.

  5. MET signalling in primary colon epithelial cells leads to increased transformation irrespective of aberrant Wnt signalling

    Science.gov (United States)

    Boon, E M J; Kovarikova, M; Derksen, P W B; van der Neut, R

    2005-01-01

    It has been shown that in hereditary and most sporadic colon tumours, components of the Wnt pathway are mutated. The Wnt target MET has been implicated in the development of colon cancer. Here, we show that overexpression of wild-type or a constitutively activated form of MET in colon epithelial cells leads to increased transformation irrespective of Wnt signalling. Fetal human colon epithelial cells without aberrant Wnt signalling were transfected with wild-type or mutated MET constructs. Expression of these constructs leads to increased phosphorylation of MET and its downstream targets PKB and MAPK. Upon stimulation with HGF, the expression of E-cadherin is downregulated in wild-type MET-transfected cells, whereas cells expressing mutated MET show low E-cadherin levels independent of stimulation with ligand. This implies a higher migratory propensity of these cells. Furthermore, fetal human colon epithelial cells expressing the mutated form of MET have colony-forming capacity in soft agar, while cells expressing wild-type MET show an intermediate phenotype. Subcutaneous injection of mutated MET-transfected cells in nude mice leads to the formation of tumours within 12 days in all mice injected. At this time point, mock-transfected cells do not form tumours, while wild-type MET-transfected cells form subcutaneous tumours in one out of five mice. We thus show that MET signalling can lead to increased transformation of colon epithelial cells independent of Wnt signalling and in this way could play an essential role in the onset and progression of colorectal cancer. PMID:15785735

  6. The effect of cell passage on the susceptibility of BALB/3T3 clone A31-1-1 cells to 3-methylcholanthrene-induced morphological transformation.

    Science.gov (United States)

    Sheu, C W; Moreland, F M; Dunkel, V C

    1987-01-01

    The response of BALB/3T3 clone A31-1-1 cells to chemically induced morphological transformation was evaluated using 3-methylcholanthrene (MCA). Stock cultures were initiated from cryopreserved cells, grown in T25 flasks containing 5 ml of medium, and replated at subconfluency. Serially transferred cells were then subjected to transformation assay. After 24-hr seeding, cells were incubated 48 hr with MCA in a 5% CO2 incubator. They were then rinsed and incubated for an additional 4 weeks with twice weekly medium change. Type III foci were scored after fixation and staining with Giemsa. With serial passage from the frozen state, cells of passages 3-14 had a low level of spontaneous transformation; zero to 6 type III foci per 20 dishes were counted. In the MCA-treated cultures the number of transformed foci, however, increased with passage. Such passage-related sensitivity to MCA was demonstrated for cells cultured in two batches of sera: one from MA Bioproducts (Lot no. 2E052) and the other from Armour Pharmaceuticals (Lot no. Y65801). The passage-related increase in number of transformed foci was not related to doubling time, cloning efficiency, or MCA-induced growth inhibition.

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

    Science.gov (United States)

    Pelch, Katherine E; Tokar, Erik J; Merrick, B Alex; Waalkes, Michael P

    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 10μM Cd for 11weeks (CTPE) or 5μM iAs for 29weeks (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. Published by Elsevier Inc.

  8. Increased OXPHOS activity precedes rise in glycolytic rate in H-RasV12/E1A transformed fibroblasts that develop a Warburg phenotype

    Directory of Open Access Journals (Sweden)

    Pluk Helma

    2009-07-01

    Full Text Available Abstract Background The Warburg phenotype in cancer cells has been long recognized, but there is still limited insight in the consecutive metabolic alterations that characterize its establishment. We obtained better understanding of the coupling between metabolism and malignant transformation by studying mouse embryonic fibroblast-derived cells with loss-of-senescence or H-RasV12/E1A-transformed phenotypes at different stages of oncogenic progression. Results Spontaneous immortalization or induction of senescence-bypass had only marginal effects on metabolic profiles and viability. In contrast, H-RasV12/E1A transformation initially caused a steep increase in oxygen consumption and superoxide production, accompanied by massive cell death. During prolonged culture in vitro, cell growth rate increased gradually, along with tumor forming potential in in vitro anchorage-independent growth assays and in vivo tumor formation assays in immuno-deficient mice. Notably, glucose-to-lactic acid flux increased with passage number, while cellular oxygen consumption decreased. This conversion in metabolic properties was associated with a change in mitochondrial NAD+/NADH redox, indicative of decreased mitochondrial tricarboxic acid cycle and OXPHOS activity. Conclusion The high rate of oxidative metabolism in newly transformed cells is in marked contrast with the high glycolytic rate in cells in the later tumor stage. In our experimental system, with cells growing under ambient oxygen conditions in nutrient-rich media, the shift towards this Warburg phenotype occurred as a step-wise adaptation process associated with augmented tumorigenic capacity and improved survival characteristics of the transformed cells. We hypothesize that early-transformed cells, which potentially serve as founders for new tumor masses may escape therapies aimed at metabolic inhibition of tumors with a fully developed Warburg phenotype.

  9. Activated platelet-derived growth factor autocrine pathway drives the transformed phenotype of a human glioblastoma cell line.

    Science.gov (United States)

    Vassbotn, F S; Ostman, A; Langeland, N; Holmsen, H; Westermark, B; Heldin, C H; Nistér, M

    1994-02-01

    Human glioblastoma cells (A172) were found to concomitantly express PDGF-BB and PDGF beta-receptors. The receptors were constitutively autophosphorylated in the absence of exogenous ligand, suggesting the presence of an autocrine PDGF pathway. Neutralizing PDGF antibodies as well as suramin inhibited the autonomous PDGF receptor tyrosine kinase activity and resulted in up-regulation of receptor protein. The interruption of the autocrine loop by the PDGF antibodies reversed the transformed phenotype of the glioblastoma cell, as determined by (1) diminished DNA synthesis, (2) inhibition of tumor colony growth, and (3) reversion of the transformed morphology of the tumor cells. The PDGF antibodies showed no effect on the DNA synthesis of another glioblastoma cells line (U-343MGa 31L) or on Ki-ras-transformed fibroblasts. The present study demonstrates an endogenously activated PDGF pathway in a spontaneous human glioblastoma cell line. Furthermore, we provide evidence that the autocrine PDGF pathway drives the transformed phenotype of the tumor cells, a process that can be blocked by extracellular antagonists.

  10. Radiation-induced irreparable heritable changes in cells promoting their tumoral transformation

    International Nuclear Information System (INIS)

    Kuzin, A.M.; Vagabova, M.Eh.; Yurov, S.S.

    1988-01-01

    In experiments with model plant tumors (Kalanchoe-ti plasmid Agrobat. tumefaciens C-58D) it was shown that exposure of the recepient plant to low-level γ-radiation of Gy induced changes in cells that were not repaired over two months promoting tumoral transformations in them. Those changes were shown to persist in the offspring of the exposed somatic cells

  11. Promoting effect of bile acids on neoplastic transformation of x-irradiated 10T1/2 cells

    International Nuclear Information System (INIS)

    Han, A.; Hill, C.K.

    1984-01-01

    Experimental studies have raised a concern about a role of bile acids in colo-rectal carcinogenesis. Studies in vivo suggest that bile acids may act as tumor promoters. Using 10T1/2 mouse cells as a model system, the authors explored the effects of cholic and cheno-deoxycholic acid on x-ray-induced neoplastic transformation in these cells. Addition of either cheno-deoxycholic acid or cholic acid to 10T1/2 cells, 24 hours after exposure to x-rays (50kv) increases significantly the frequencies of transformation. The compounds were present in the medium throughout the entire postirradiation refeeding period. At the concentrations used (0.5μg/ml), neither acid was cytotoxic and did not have any effect on cell survival. The enhancement of radiation-induced transformation seems to be greater in the presence of cholic acid, as compared to the effect of cheno-deoxycholic acid. Increase in transformation was relatively greater after low compared to high doses of radiation. The effect of bile acids on transformation of 10T1/2 cells is similar to that of a known tumor promoter TPA. The authors' observations support the conclusion that promotional effect of bile acids is not because of their specific effect on colonic epithelium, but rather due to their general properties as tumor promoters

  12. STAT3-regulated exosomal miR-21 promotes angiogenesis and is involved in neoplastic processes of transformed human bronchial epithelial cells.

    Science.gov (United States)

    Liu, Yi; Luo, Fei; Wang, Bairu; Li, Huiqiao; Xu, Yuan; Liu, Xinlu; Shi, Le; Lu, Xiaolin; Xu, Wenchao; Lu, Lu; Qin, Yu; Xiang, Quanyong; Liu, Qizhan

    2016-01-01

    Although microRNA (miRNA) enclosed in exosomes can mediate intercellular communication, the roles of exosomal miRNA and angiogenesis in lung cancer remain unclear. We investigated functions of STAT3-regulated exosomal miR-21 derived from cigarette smoke extract (CSE)-transformed human bronchial epithelial (HBE) cells in the angiogenesis of CSE-induced carcinogenesis. miR-21 levels in serum were higher in smokers than those in non-smokers. The medium from transformed HBE cells promoted miR-21 levels in normal HBE cells and angiogenesis of human umbilical vein endothelial cells (HUVEC). Transformed cells transferred miR-21 into normal HBE cells via exosomes. Knockdown of STAT3 reduced miR-21 levels in exosomes derived from transformed HBE cells, which blocked the angiogenesis. Exosomes derived from transformed HBE cells elevated levels of vascular endothelial growth factor (VEGF) in HBE cells and thereby promoted angiogenesis in HUVEC cells. Inhibition of exosomal miR-21, however, decreased VEGF levels in recipient cells, which blocked exosome-induced angiogenesis. Thus, miR-21 in exosomes leads to STAT3 activation, which increases VEGF levels in recipient cells, a process involved in angiogenesis and malignant transformation of HBE cells. These results, demonstrating the function of exosomal miR-21 from transformed HBE cells, provide a new perspective for intervention strategies to prevent carcinogenesis of lung cancer. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  13. Adult T-cell leukemia: molecular basis for clonal expansion and transformation of HTLV-1-infected T cells.

    Science.gov (United States)

    Watanabe, Toshiki

    2017-03-02

    Adult T-cell leukemia (ATL) is an aggressive T-cell malignancy caused by human T-cell leukemia virus type 1 (HTLV-1) that develops through a multistep carcinogenesis process involving 5 or more genetic events. We provide a comprehensive overview of recently uncovered information on the molecular basis of leukemogenesis in ATL. Broadly, the landscape of genetic abnormalities in ATL that include alterations highly enriched in genes for T-cell receptor-NF-κB signaling such as PLCG1 , PRKCB , and CARD11 and gain-of function mutations in CCR4 and CCR7 Conversely, the epigenetic landscape of ATL can be summarized as polycomb repressive complex 2 hyperactivation with genome-wide H3K27 me3 accumulation as the basis of the unique transcriptome of ATL cells. Expression of H3K27 methyltransferase enhancer of zeste 2 was shown to be induced by HTLV-1 Tax and NF-κB. Furthermore, provirus integration site analysis with high-throughput sequencing enabled the analysis of clonal composition and cell number of each clone in vivo, whereas multicolor flow cytometric analysis with CD7 and cell adhesion molecule 1 enabled the identification of HTLV-1-infected CD4 + T cells in vivo. Sorted immortalized but untransformed cells displayed epigenetic changes closely overlapping those observed in terminally transformed ATL cells, suggesting that epigenetic abnormalities are likely earlier events in leukemogenesis. These new findings broaden the scope of conceptualization of the molecular mechanisms of leukemogenesis, dissecting them into immortalization and clonal progression. These recent findings also open a new direction of drug development for ATL prevention and treatment because epigenetic marks can be reprogrammed. Mechanisms underlying initial immortalization and progressive accumulation of these abnormalities remain to be elucidated. © 2017 by The American Society of Hematology.

  14. 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).

  15. Appearance and evolution of the specific chromosomal rearrangements associated with malignant transformation of mouse m5S cells

    International Nuclear Information System (INIS)

    Kodama, S.; Okumura, Y.; Komatsu, K.; Sasaki, M.S.

    1991-01-01

    Chromosomal alterations were studied during the acquisition of malignant phenotypes in two karyotypically distinct cells isolated from transformed foci induced by x-irradiation in mouse m5S cells. Because the transformants, despite foci origin, showed low ability to grow in agar, they were cultured in vitro with serial transfer schedules to allow further cell generations and assayed for anchorage independence (AI) at each passage level. The AI frequency increased with the cell doubling numbers. Chromosome analysis showed that a focus was one cell origin, but the transformants showed karyotypic instability during cell proliferation, giving rise to the rearrangements clustered in the distal region of the specific chromosomes. These rearrangements appeared to be directed toward the acquisition of malignant phenotypes. Analysis of the types and sites of rearrangements indicated that a mechanism exists that induces frequent rearrangements of the specific region of a chromosome during the process of transformation into the malignant state

  16. Intra-hydrogel culture prevents transformation of mesenchymal stem cells induced by monolayer expansion.

    Science.gov (United States)

    Jiang, Tongmeng; Liu, Junting; Ouyang, Yiqiang; Wu, Huayu; Zheng, Li; Zhao, Jinmin; Zhang, Xingdong

    2018-05-01

    In this study, we report that the intra-hydrogel culture system mitigates the transformation of mesenchymal stem cells (MSCs) induced by two-dimensional (2D) expansion. MSCs expanded in monolayer culture prior to encapsulation in collagen hydrogels (group eMSCs-CH) featured impaired stemness in chondrogenesis, comparing with the freshly isolated bone marrow mononuclear cells seeded directly in collagen hydrogels (group fMSCs-CH). The molecular mechanism of the in vitro expansion-triggered damage to MSCs was detected through genome-wide microarray analysis. Results indicated that pathways such as proteoglycans in cancer and pathways in cancer expansion were highly enriched in eMSCs-CH. And multiple up-regulated oncoma-associated genes were verified in eMSCs-CH compared with fMSCs-CH, indicating that expansion in vitro triggered cellular transformation was associated with signaling pathways related to tumorigenicity. Besides, focal adhesion (FA) and mitogen-activated protein kinase (MAPK) signaling pathways were also involved in in vitro expansion, indicating restructuring of the cell architecture. Thus, monolayer expansion in vitro may contribute to vulnerability of MSCs through the regulation of FA and MAPK. This study indicates that intra-hydrogel culture can mitigate the monolayer expansion induced transformation of MSCs and maintain the uniformity of the stem cells, which is a viable in vitro culture system for stem cell therapy.

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

    International Nuclear Information System (INIS)

    Pelch, Katherine E.; Tokar, Erik J.; Merrick, B. Alex; Waalkes, Michael P.

    2015-01-01

    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

  18. 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

  19. Role of growth factors in the growth of normal and transformed cells

    International Nuclear Information System (INIS)

    Lokeshwar, V.B.

    1989-01-01

    Growth factors play an important role in the growth of normal cells. However, their untimely and/or excess production leads to neoplastic transformation. The role of growth factors in the growth of normal cells was studied by investigating the mechanism of transmodulation of the cell surface EGF receptor number by protamine. Protamine increased the EGF stimulated mitogenic response in Swiss mouse 3T3 cells and A431 cells by increasing the number of functionally active EGF receptors. Protamine also increased EGF receptor number in plasma membranes and solubilized membranes. This was evidenced by an increase in both 125 I-EGF-EGF-receptor complex and EGF stimulated phosphorylation of the EGF receptor. The solubilized EGF receptor was retained on a protamine-agarose gel indicating that protamine might increase EGF receptor number by directly activating cryptic EGF receptors in the plasma membranes. The role of growth factors in neoplastic transformation was studied by investigating the role of the oncogene v-sis in the growth of Simian sarcoma virus (SSV) transformed cells. The product of the oncogene v-sis is 94% homologous to the B chain of PDGF. This study found that (i) v-sis gene product is synthesized as a 32 kDa unglycosylated monomer which is glycosylated, dimerized and proteolytically processed into p36, p72, p68, p58, p44 and p27 mol. wt. species respectively. (ii) p36, p72, p68 and p58 are very likely formed in the endoplasmic reticulum and/or Golgi complex. A fraction of newly synthesized p72, p68 and p58 is degraded intracellularly at a fast rate. (iii) p44 is a secretory product which remains tightly associated with the cell surface. p44 is recaptured by the cells through interaction with cell surface PDGF receptors and degraded into p27. (iv) During long term cultures p44 is extracellularly cleaved into a 27 kDa product

  20. Amplification of the Ect2 proto-oncogene and over-expression of Ect2 mRNA and protein in nickel compound and methylcholanthrene-transformed 10T1/2 mouse fibroblast cell lines

    International Nuclear Information System (INIS)

    Clemens, Farrah; Verma, Rini; Ramnath, Jamuna; Landolph, Joseph R.

    2005-01-01

    Occupational exposure of humans to mixtures of insoluble and soluble nickel (Ni) compounds correlates with increased incidences of lung, sinus, and pharyngeal tumors. Specific insoluble Ni compounds are carcinogenic to animals by inhalation and induce morphological and neoplastic transformation of cultured rodent cells. Our objectives were to (1) understand mechanisms of nickel ion-induced cell transformation, hence carcinogenesis and (2) develop biomarkers of nickel ion exposure and nickel ion-induced cell transformation. We isolated mRNAs from green nickel oxide (NiO), crystalline nickel monosulfide (NiS), and 3-methylcholanthrene (MCA) transformed C3H/10T1/2 Cl 8 cell lines, and determined by mRNA differential display that nine mRNA fragments were differentially expressed between Ni transformed and non-transformed 10T1/2 cell lines. Fragment R2-5 was expressed at higher steady-state levels in the transformed cell lines. R2-5 had 100% sequence identity to part of the coding region of Ect2, a mouse proto-oncogene encoding a GDP-GTP exchange factor. The 3.9-kb Ect2 transcript was expressed at 1.6- to 3.6-fold higher steady-state levels in four Ni transformed, and in two MCA-transformed, cell lines. Ect2 protein was expressed at 3.0- to 4.5-fold higher steady-state levels in Ni-transformed and in MCA-transformed cell lines. The Ect2 gene was amplified by 3.5- to 10-fold in Ni transformed, and by 2.5- to 3-fold in MCA transformed cell lines. Binding of nickel ions to enzymes of DNA synthesis likely caused amplification of the Ect2 gene. Ect2 gene amplification and over-expression of Ect2 mRNA and protein can cause microtubule disassembly and cytokinesis, contributing to induction and maintenance of morphological, anchorage-independent, and neoplastic transformation of these cell lines. Over-expression of Ect2 protein is a useful biomarker to detect exposure to nickel compounds and nickel ion-induced morphological and neoplastic cell transformation

  1. Loss of C/EBP alpha cell cycle control increases myeloid progenitor proliferation and transforms the neutrophil granulocyte lineage

    DEFF Research Database (Denmark)

    Porse, Bo T; Bryder, David; Theilgaard-Mönch, Kim

    2005-01-01

    dissociate the ability of C/EBP alpha to block cell cycle progression through E2F inhibition from its function as a transcriptional activator impair the in vivo development of the neutrophil granulocyte and adipose lineages. We now show that such mutations increase the capacity of bone marrow (BM) myeloid...... progenitors to proliferate, and predispose mice to a granulocytic myeloproliferative disorder and transformation of the myeloid compartment of the BM. Both of these phenotypes were transplantable into lethally irradiated recipients. BM transformation was characterized by a block in granulocyte differentiation...

  2. Cell transformation in vitro by fast neutrons of different energies: implications for mechanisms

    International Nuclear Information System (INIS)

    Barendsen, G.W.; Gaiser, J.F.

    1985-01-01

    Studies have been performed to analyse the dependence of the induction of cell transformation and cell reproductive death in cultures of C3H/10T1/2 cells, NBCH-3 cells and WAGR-2 cells on the energy of mono-energetic fast neutrons. The dose-effect relations for 300 kV, 4.2 MeV X rays, 15 MeV and 0.5 MeV neutrons have been analysed on the basis of the representations F(D) = t 1 D+t 2 D 2 and S(D)/S(0) = exp [-a 1 D+a 2 D 2 )] for transformation and survival respectively. The results show that a 1 values for all radiations are a factor of approximately 10 3 larger than corresponding t 1 values. The RBE values for cell reproductive death derived as ratios of a 1 for the various neutrons and 300 kV x rays are similar to the corresponding RBE values for cell transformation derived as ratios of t 1 values of neutrons and X rays. These similarities in the RBE values and differences in absolute values of a 1 and t 1 can be compared with results from published dose-effect relations for reproductive death and chromosome aberrations obtained for other cell lines. The insights obtained can be applied to derive a hypothesis about the induction of these effects, assuming similarities in energy requirements and physico-chemical primary mechanisms of the induction of damage in chromosomes and differences in the specificities of the sites and total size of the targets on chromosomes associated with the various endpoints observed. (author)

  3. Analysis of renal cell transformation following exposure to trichloroethene in vivo and its metabolite S-(dichlorovinyl)-L-cysteine in vitro

    International Nuclear Information System (INIS)

    Mally, Angela; Walker, Cheryl L.; Everitt, Jeffrey I.; Dekant, Wolfgang; Vamvakas, Spiros

    2006-01-01

    Trichloroethene (TCE) is classified as a potential human carcinogen although there is a significant debate regarding the mechanism of TCE induced renal tumor formation. This controversy stems in part from the extremely high doses of TCE required to induce renal tumors and the potential contribution of the associated nephrotoxicity to tumorigenesis. We have used Eker rats, which are uniquely susceptible to renal carcinogens, to determine if exposures to TCE in vivo or exposure to its metabolite S-(dichlorovinyl)-L-cysteine (DCVC) in vitro can transform kidney epithelial cells in the absence of cytotoxicity. Treatment with TCE (0, 100, 250, 500, 1000 mg/kg bw by gavage, 5 days a week) for 13 weeks resulted in a significant increase in cell proliferation in kidney tubule cells, but did not enhance formation of preneoplastic lesions or tumor incidence in Eker rat kidneys as compared to controls. In vitro, concentrations of DCVC, which reduced cell survival to 50%, were able to transform rat kidney epithelial cells. However, no carcinogen-specific mutations were identified in the VHL or Tsc-2 tumor suppressor genes in the transformants. Taken together, the inability of TCE to enhance formation of preneoplastic changes or neoplasia and the absence of carcinogen-specific alteration of genes accepted to be critical for renal tumor development suggest that TCE mediated carcinogenicity may occur secondary to continuous toxic injury and sustained regenerative cell proliferation

  4. 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.

  5. p53 functional impairment and high p21waf1/cip1 expression in human T-cell lymphotropic/leukemia virus type I-transformed T cells.

    Science.gov (United States)

    Cereseto, A; Diella, F; Mulloy, J C; Cara, A; Michieli, P; Grassmann, R; Franchini, G; Klotman, M E

    1996-09-01

    Human T-cell lymphotropic/leukemia virus type I (HTLV-I) is associated with T-cell transformation both in vivo and in vitro. Although some of the mechanisms responsible for transformation remain unknown, increasing evidence supports a direct role of viral as well as dysregulated cellular proteins in transformation. We investigated the potential role of the tumor suppressor gene p53 and of the p53-regulated gene, p21waf1/cip1 (wild-type p53 activated fragment 1/cycling dependent kinases [cdks] interacting protein 1), in HTLV-I-infected T cells. We have found that the majority of HTLV-I-infected T cells have the wild-type p53 gene. However, its function in HTLV-I-transformed cells appears to be impaired, as shown by the lack of appropriate p53-mediated responses to ionizing radiation (IR). Interestingly, the expression of the p53 inducible gene, p21waf1/cip1, is elevated at the messenger ribonucleic acid and protein levels in all HTLV-I-infected T-cell lines examined as well as in Taxl-1, a human T-cell line stably expressing Tax. Additionally, Tax induces upregulation of a p21waf1/cip1 promoter-driven luciferase gene in p53 null cells, and increases p21waf1/cip1 expression in Jurkat T cells. These findings suggest that the Tax protein is at least partially responsible for the p53-independent expression of p21waf1/cip1 in HTLV-I-infected cells. Dysregulation of p53 and p21waf1/cip1 proteins regulating cell-cycle progression, may represent an important step in HTLV-I-induced T-cell transformation.

  6. Cell surface alteration in Epstein-Barr virus-transformed cells from patients with extreme insulin resistance

    International Nuclear Information System (INIS)

    Gorden, D.L.; Robert, A.; Moncada, V.Y.; Taylor, S.I.; Muehlhauser, J.C.; Carpentier, J.L.

    1990-01-01

    An abnormality was detected in the morphology of the cell surface of Epstein-Barr virus-transformed lymphocytes of patients with genetic forms of insulin resistance. In cells from two patients with leprechaunism and two patients with type A extreme insulin resistance, scanning electron microscopy demonstrated a decrease in the percentage of the cell surface occupied by microvilli in cells from the patients with leprechaunism and type A insulin resistance compared with control cells. When cells from a healthy control subject and one of the patients with leprechaunism (Lep/Ark-1) were incubated with 125 I-labeled insulin, there was a decrease in the percentage of 125 I-insulin associated with microvilli on the cell surface. Thus, the decreased localization of insulin receptors with the microvillous region of the cell surface was in proportion to the decrease in microvilli

  7. p53 regulates the proliferation, differentiation and spontaneous transformation of mesenchymal stem cells

    Energy Technology Data Exchange (ETDEWEB)

    Armesilla-Diaz, Alejandro, E-mail: aarmesilla@cib.csic.es [Department of Cellular and Molecular Physiopathology, Centro de Investigaciones Biologicas, CSIC, Ramiro de Maeztu, 9, 28040 Madrid (Spain); Elvira, Gema; Silva, Augusto [Department of Cellular and Molecular Physiopathology, Centro de Investigaciones Biologicas, CSIC, Ramiro de Maeztu, 9, 28040 Madrid (Spain)

    2009-12-10

    Mesenchymal stem cells (MSC) have been extensively studied and gained wide popularity due to their therapeutic potential. Spontaneous transformation of MSC, from both human and murine origin, has been reported in many studies. MSC transformation depends on the culture conditions, the origin of the cells and the time on culture; however, the precise biological characteristics involved in this process have not been fully defined yet. In this study, we investigated the role of p53 in the biology and transformation of murine bone marrow (BM)-derived MSC. We demonstrate that the MSC derived from p53KO mice showed an augmented proliferation rate, a shorter doubling time and also morphologic and phenotypic changes, as compared to MSC derived from wild-type animals. Furthermore, the MSC devoid of p53 had an increased number of cells able to generate colonies. In addition, not only proliferation but also MSC differentiation is controlled by p53 since its absence modifies the speed of the process. Moreover, genomic instability, changes in the expression of c-myc and anchorage independent growth were also observed in p53KO MSC. In addition, the absence of p53 implicates the spontaneous transformation of MSC in long-term cultures. Our results reveal that p53 plays a central role in the biology of MSC.

  8. Oncogenic transformation systems involving mammalian cells in vitro to determine the relative risks of different treatment modalities

    International Nuclear Information System (INIS)

    Hall, E.J.

    1984-01-01

    An established line of mouse fibroblasts cultured in vitro were used to compare the incidence of oncogenic transformation produced by X-rays, heat, various hypoxid cell radiosensitizers and used chemotherapy agents. A variety of 2 and 5 substituted nitroimidazoles were tested; these included metronidazole, desmethylmisonidazole, misonidazole, SR-2508, SR-2555, Ro-0741, RSU-1047 and RSU-1021. Most of these sensitizers produced a similar level of transformation; for example a three day exposure of aerated cells to a concentration of 1 mM of the drug resulted in a transformation incidence comparable to 1Gy of X-rays. The notable exception was SR-2508 which produced a five-fold higher incidence of transformation. The potential carcinogenicity of sensitizers must be considered in choosing which of the currently available new drugs is to be used in clinical trials as an alternative to misonidazole. A variety of chemotherapy agents were tested at a concentration comparable to those used clinically and matched to produce about the same amount of cell killing. It was found that the incidence of oncogenic transformation varied widely. Some agents, such as Vincristine did not produce transformation at a level that could be detected above background, while others such as cis-Platinum appear to be potent carcinogens and produced transformation at a rate an order of magnitude higher than can be achieved by any dose of X-rays. Hyperthermia in the range of 40 0 C caused no transformation, whether or not the heat treatment was associated with significant cell killing. In addition modest hyperthermia appreciably reduced the transformation frequencies associated with X-ray doses. (orig./MG)

  9. Suppression of X-ray induced transformation by vitamin E in mouse C3H/10T1/2 cells

    International Nuclear Information System (INIS)

    Radner, B.S.; Kennedy, A.R.

    1986-01-01

    Vitamin E (d-α-tocopherol) was shown to decrease X-ray induced transformation in mouse C3H/10 1/2 cells. The d-α-tocopherol was active in the form of succinate diluted in ethanol, but was inactive at the highest non-toxic concentration of the pure substance dissolved in oil and diluted in acetone. Vitamin E succinate was effective when present only for the early portion of the radiation transformation assay period, indicating that its effect may be reversible. Vitamin E did not supress the growth and expression of transformed C3H/10 1/2 cells as foci when transformed cells were surrounded by a monolayer of normal cells. (author)

  10. 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

  11. 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.

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

    International Nuclear Information System (INIS)

    Pratheeshkumar, Poyil; Son, Young-Ok; Divya, Sasidharan Padmaja; Roy, Ram Vinod; Hitron, John Andrew; Wang, Lei; Kim, Donghern; Dai, Jin; Asha, Padmaja; Zhang, Zhuo; Wang, Yitao; Shi, Xianglin

    2014-01-01

    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.

  13. NKp46 identifies an NKT cell subset susceptible to leukemic transformation in mouse and human

    Science.gov (United States)

    Yu, Jianhua; Mitsui, Takeki; Wei, Min; Mao, Hsiaoyin; Butchar, Jonathan P.; Shah, Mithun Vinod; Zhang, Jianying; Mishra, Anjali; Alvarez-Breckenridge, Christopher; Liu, Xingluo; Liu, Shujun; Yokohama, Akihiko; Trotta, Rossana; Marcucci, Guido; Benson, Don M.; Loughran, Thomas P.; Tridandapani, Susheela; Caligiuri, Michael A.

    2011-01-01

    IL-15 may have a role in the development of T cell large granular lymphocyte (T-LGL) or NKT leukemias. However, the mechanisms of action and the identity of the cell subset that undergoes leukemic transformation remain elusive. Here we show that in both mice and humans, NKp46 expression marks a minute population of WT NKT cells with higher activity and potency to become leukemic. Virtually 100% of T-LGL leukemias in IL-15 transgenic mice expressed NKp46, as did a majority of human T-LGL leukemias. The minute NKp46+ NKT population, but not the NKp46– NKT population, was selectively expanded by overexpression of endogenous IL-15. Importantly, IL-15 transgenic NKp46– NKT cells did not become NKp46+ in vivo, suggesting that NKp46+ T-LGL leukemia cells were the malignant counterpart of the minute WT NKp46+ NKT population. Mechanistically, NKp46+ NKT cells possessed higher responsiveness to IL-15 in vitro and in vivo compared with that of their NKp46– NKT counterparts. Furthermore, interruption of IL-15 signaling using a neutralizing antibody could prevent LGL leukemia in IL-15 transgenic mice. Collectively, our data demonstrate that NKp46 identifies a functionally distinct NKT subset in mice and humans that appears to be directly susceptible to leukemic transformation when IL-15 is overexpressed. Thus, IL-15 signaling and NKp46 may be useful targets in the treatment of patients with T-LGL or NKT leukemia. PMID:21364281

  14. Radiation-induced transformation of SV40-immortalized human thyroid epithelial cells by single and fractionated exposure to γ-irradiation in vitro

    International Nuclear Information System (INIS)

    Riches, A.C.; Herceg, Z.; Bryant, P.E.; Wynford-Thomas, D.

    1994-01-01

    Radiation-induced transformation of a human thyroid epithelial cell line (HTori-3) has been investigated following exposure to single and fractionated doses of γ-irradiation. The human epithelial cells were irradiated in vitro and following passaging, transplanted to the athymic nude mouse. Following a single exposure to γ-irradiation in the range 0.5-4Gy, 22 tumours were observed in 45 recipients and following three equal fractions in the range 0.5-4Gy per fraction, 18 tumours were observed in 31 recipients. Tumours were undifferentiated carcinomas and were observed from 7 to 20 weeks after transplantation. They occurred after similar radiation doses to those received by the children in the Belarus region of Ukraine, who developed thyroid tumours. The number of tumours observed, in each group receiving cells irradiated with a single dose of γ-irradiation in the range 0.5-4 Gy, was similar. Cell lines were established from some tumours and the tumorigenicity confirmed by retransplantation. These tumour cell lines were more radiosensitive than the human thyroid epithelial cell line they were derived from. This indicates that transformed cells were not being selected from a subpopulation within the parent cell line but that radiation-induced transformants were being induced de novo. The human origin of the tumours was established by karyotyping, immunocytochemical demonstration of human epithelial cytokeratins and p53 analysis. DNA fingerprinting confirmed that the tumours were derived from the original cell line. (author)

  15. Education and Development: Twelve Considerations for Transformative Practice

    Science.gov (United States)

    VanBalkom, W. Duffie; Eastham, Sarada

    2011-01-01

    Twelve factors that are essential to consider when embarking on the process of transformative development are examined in the context of international development programming in education and training. Each factor raises a number of questions for the deliberations of policy makers, development practitioners, scholars, international educators,…

  16. A Small Molecule Inhibitor Selectively Induces Apoptosis in Cells Transformed by High Risk Human Papilloma Viruses.

    Directory of Open Access Journals (Sweden)

    Amy K Sheaffer

    Full Text Available A phenotypic high-throughput cell culture screen was performed to identify compounds that prevented proliferation of the human Papilloma virus type 16 (HPV-16 transformed cell line Ca Ski. A series of quinoxaline compounds exemplified by Compound 1 was identified. Testing against a panel of cell lines demonstrated that Compound 1 selectively inhibited replication of all HPV-16, HPV-18, and HPV-31 transformed cell lines tested with 50% Inhibitory Concentration (IC50 values of 2 to 8 μM relative to IC50 values of 28 to 73 μM in HPV-negative cell lines. Treatment with Compound 1 resulted in a cascade of multiple apoptotic events, including selective activation of effector caspases 3 and 7, fragmentation of cellular DNA, and PARP (poly(ADP-ribose polymerase cleavage in HPV-positive cells relative to HPV-negative cells. Unregulated proliferation of HPV transformed cells is dependent on the viral oncogenes, E6 and E7. Treatment with Compound 1 resulted in a decrease in HPV E7 protein in Ca Ski cells. However, the timing of this reduction relative to other effects of compound treatment suggests that this was a consequence, rather than a cause, of the apoptotic cascade. Likewise, compound treatment resulted in no obvious effects on the E6- and E7- mediated down regulation of p53 and Rb, or their downstream effectors, p21 or PCNA. Further investigation of apoptotic signals induced by Compound 1 revealed cleavage of Caspase-8 in HPV-positive cells as early as 2 hours post-treatment, suggesting the compound initiates apoptosis through the extrinsic, death receptor-mediated, pathway of cell death. These studies provide proof of concept that cells transformed by oncogenic Papillomaviruses can be selectively induced to undergo apoptosis by compound treatment.

  17. Merkel Cell Polyomavirus Small T Antigen Promotes Pro-Glycolytic Metabolic Perturbations Required for Transformation.

    Directory of Open Access Journals (Sweden)

    Christian Berrios

    2016-11-01

    Full Text Available Merkel cell polyomavirus (MCPyV is an etiological agent of Merkel cell carcinoma (MCC, a highly aggressive skin cancer. The MCPyV small tumor antigen (ST is required for maintenance of MCC and can transform normal cells. To gain insight into cellular perturbations induced by MCPyV ST, we performed transcriptome analysis of normal human fibroblasts with inducible expression of ST. MCPyV ST dynamically alters the cellular transcriptome with increased levels of glycolytic genes, including the monocarboxylate lactate transporter SLC16A1 (MCT1. Extracellular flux analysis revealed increased lactate export reflecting elevated aerobic glycolysis in ST expressing cells. Inhibition of MCT1 activity suppressed the growth of MCC cell lines and impaired MCPyV-dependent transformation of IMR90 cells. Both NF-κB and MYC have been shown to regulate MCT1 expression. While MYC was required for MCT1 induction, MCPyV-induced MCT1 levels decreased following knockdown of the NF-κB subunit RelA, supporting a synergistic activity between MCPyV and MYC in regulating MCT1 levels. Several MCC lines had high levels of MYCL and MYCN but not MYC. Increased levels of MYCL was more effective than MYC or MYCN in increasing extracellular acidification in MCC cells. Our results demonstrate the effects of MCPyV ST on the cellular transcriptome and reveal that transformation is dependent, at least in part, on elevated aerobic glycolysis.

  18. A comprehensive review of metal-induced cellular transformation studies.

    Science.gov (United States)

    Chen, Qiao Yi; Costa, Max

    2017-09-15

    In vitro transformation assays not only serve practical purposes in screening for potential carcinogenic substances in food, drug, and cosmetic industries, but more importantly, they provide a means of understanding the critical biological processes behind in vivo cancer development. In resemblance to cancer cells in vivo, successfully transformed cells display loss of contact inhibition, gain of anchorage independent growth, resistant to proper cell cycle regulation such as apoptosis, faster proliferation rate, potential for cellular invasion, and ability to form tumors in experimental animals. Cells purposely transformed using metal exposures enable researchers to examine molecular changes, dissect various stages of tumor formation, and ultimately elucidate metal induced cancer mode of action. For practical purposes, this review specifically focuses on studies incorporating As-, Cd-, Cr-, and Ni-induced cell transformation. Through investigating and comparing an extensive list of studies using various methods of metal-induced transformation, this review serves to bridge an information gap and provide a guide for avoiding procedural discrepancies as well as maximizing experimental efficiency. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. Modulating factors in the expression of radiation-induced oncogenic transformation

    International Nuclear Information System (INIS)

    Hall, E.J.; Hei, T.K.

    1990-01-01

    Many assays for oncogenic transformation have been developed ranging from those in established rodent cell lines where morphological alteration is scored, to those in human cells growing in nude mice where tumor invasiveness is scored. In general, systems that are most quantitaive are also the least relevant in terms of human carcinogenesis and human risk estimation. The development of cell culture systems has made it possible to assess at the cellular level the oncogenic potential of a variety of chemical, physical and viral agents. Cell culture systems afford the opportunity to identify factors and conditions that may prevent or enhance cellular transformation by radiation and chemicals. Permissive and protective factors in radiation-induced transformation include thyroid hormone and the tumor promoter TPA that increase the transformation incidence for a given dose of radiation, and retinoids, selenium, vitamin E, and 5-aminobenzamide that inhibit the expression of transformation. Densely ionizing α-particles, similar to those emitted by radon daughters, are highly effective in inducing transformations and appear to interact in a supra-additive fashion with asbestos fibers. The activation of a known dominant oncogene has not yet been demonstrated in radiation-induced oncogenic transformation. The most likely mechanism for radiation activation of an oncogene would be via the production of a chromosomal translocation. Radiation also efficiently induces deletions and may thus lead to the loss of a suppressor gene

  20. 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.

  1. Pleomorphic adenoma cells vary in their susceptibility to SV40 transformation depending on the initial karyotype.

    Science.gov (United States)

    Kazmierczak, B; Thode, B; Bartnitzke, S; Bullerdiek, J; Schloot, W

    1992-07-01

    Chromosomal aberrations involving 8q12 or 12q13-15 characterize two cytogenetic subgroups of salivary gland pleomorphic adenomas. As the tumors of the two groups differ in their clinical and histologic characteristics, we decided to determine their susceptibility to SV40 transformation. We transfected cell cultures from 13 adenomas with aberrations involving 8q12 and from seven adenomas with involvement of 12q13-15 using an SV40 plasmid coding for the early region of the viral genome. Whereas all cultures with aberrations of 12q13-15 showed transformed foci, only 4 of the 13 cultures with 8q12 abnormalities showed foci of transformed cells. We also observed a much higher immortalization rate in the first group (3/7 vs. 1/13). All successfully transformed tumor cell cultures showed a relatively stable karyotype in the pre-crisis stage and a high mitotic index, were T-antigen positive, and had an extended life span in vitro.

  2. Inhibition of the Hedgehog Signaling Pathway Depresses the Cigarette Smoke-Induced Malignant Transformation of 16HBE Cells on a Microfluidic Chip.

    Science.gov (United States)

    Qin, Yong-Xin; Yang, Zhi-Hui; Du, Xiao-Hui; Zhao, Hui; Liu, Yuan-Bin; Guo, Zhe; Wang, Qi

    2018-05-20

    The hedgehog signaling system (HHS) plays an important role in the regulation of cell proliferation and differentiation during the embryonic phases. However, little is known about the involvement of HHS in the malignant transformation of cells. This study aimed to detect the role of HHS in the malignant transformation of human bronchial epithelial (16HBE) cells. In this study, two microfluidic chips were designed to investigate cigarette smoke extract (CSE)-induced malignant transformation of cells. Chip A contained a concentration gradient generator, while chip B had four cell chambers with a central channel. The 16HBE cells cultured in chip A were used to determine the optimal concentration of CSE for inducing malignant transformation. The 16HBE cells in chip B were cultured with 12.25% CSE (Group A), 12.25% CSE + 5 μmol/L cyclopamine (Group B), or normal complete medium as control for 8 months (Group C), to establish the in vitro lung inflammatory-cancer transformation model. The transformed cells were inoculated into 20 nude mice as cells alone (Group 1) or cells with cyclopamine (Group 2) for tumorigenesis testing. Expression of HHS proteins was detected by Western blot. Data were expressed as mean ± standard deviation. The t-test was used for paired samples, and the difference among groups was analyzed using a one-way analysis of variance. The optimal concentration of CSE was 12.25%. Expression of HHS proteins increased during the process of malignant transformation (Group B vs. Group A, F = 7.65, P < 0.05). After CSE exposure for 8 months, there were significant changes in cellular morphology, which allowed the transformed cells to grow into tumors in 40 days after being inoculated into nude mice. Cyclopamine could effectively depress the expression of HHS proteins (Group C vs. Group B, F = 6.47, P < 0.05) and prevent tumor growth in nude mice (Group 2 vs. Group 1, t = 31.59, P < 0.01). The activity of HHS is upregulated during the CSE-induced malignant

  3. Transformation of Nonfunctioning Pancreatic Neuroendocrine Carcinoma Cells into Insulin Producing Cells after Treatment with Sunitinib

    Directory of Open Access Journals (Sweden)

    Jung Hun Ohn

    2013-06-01

    Full Text Available We report a rare case of severe hypoglycemia after sunitinib treatment for pancreatic neuroendocrine carcinoma. We describe the initial clinical presentation, laboratory results, pathologic findings, and managment in a patient with a nonfunctioning pancreatic neuroendocrine carcinoma with liver metastases who developed life threatening hypoglycemia after 2 months of sunitinib therapy. A 46-year-old woman presented to the emergency department with loss of consciousness from hypoglycemia. Serum C-peptide and insulin levels at fasting state revealed that the hypoglycemia resulted from endogenous hyperinsulinemia. She had been diagnosed with nonfunctioning pancreatic neuroendocrine carcinoma based on a biopsy of metastatic cervical lymph node and was being treated with sunitinib, a small molecule tyrosine kinase inhibitor. Immunohistochemical stain of the metastatic liver mass demonstrated that the initially nonfunctioning neuroendocrine carcinoma cells had changed into insulin-producing cells after sunitinib therapy. Transarterial chemoembolization of the liver masses and systemic chemotherapy with streptozotocin/adriamycin relieved the hypoglycemia. A nonfunctioning pancreatic neuroendocrine carcinoma was transformed into an insulin-producing tumor after treatment with sunitinib, causing endogenous hyperinsulinemia and severe hypoglycemia.

  4. Transformational development in a changing context: A Latin American perspective

    Directory of Open Access Journals (Sweden)

    Angelique J.W.M. van Zeeland

    2016-05-01

    Full Text Available This article analyses the challenges for the strategies and practices of transformational development in a changing context. This reflection is based on contributions received during the process of dialogues and regional consultations, realised from August 2012 until March 2014, of the ACT Alliance, an international coalition of churches and faith-based organisations (FBOs working in the areas of humanitarian response, development and advocacy. The main processes that affect the changing development context are addressed, such as the ongoing globalisation as well as the consequences, mainly regarding the shrinking space for civil society. It discusses the concepts of human development and of transformational development, based on a people-centred development vision, a human rights-based approach and advocacy, which addresses the root causes and effects of poverty, inequality and injustice. Transformational development practices, from Latin America, are presented and analysed. The article concludes that the changing development context also offers opportunities, especially regarding regional and global alliances of FBOs, civil society organisations and of social movements.

  5. Transformational development in a changing context: A Latin American perspective

    Directory of Open Access Journals (Sweden)

    Angelique J.W.M. van Zeeland

    2016-10-01

    Full Text Available This article analyses the challenges for the strategies and practices of transformational development in a changing context. This reflection is based on contributions received during the process of dialogues and regional consultations, realised from August 2012 until March 2014, of the ACT Alliance, an international coalition of churches and faith-based organisations (FBOs working in the areas of humanitarian response, development and advocacy. The main processes that affect the changing development context are addressed, such as the ongoing globalisation as well as the consequences, mainly regarding the shrinking space for civil society. It discusses the concepts of human development and of transformational development, based on a people-centred development vision, a human rights-based approach and advocacy, which addresses the root causes and effects of poverty, inequality and injustice. Transformational development practices, from Latin America, are presented and analysed. The article concludes that the changing development context also offers opportunities, especially regarding regional and global alliances of FBOs, civil society organisations and of social movements.

  6. 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...

  7. Novel Methods for Development of Cell Factories and Laboratory Simultations

    DEFF Research Database (Denmark)

    Bonde, Mads

    engineering. A key part of the transforming towards a biobased society and development of cell factories, is a skilled workforce to address the challenges. Furthermore, new methods need to be accessible to scientists and students in order to impact future research. Part of this challenge can be addressed...... by improving education and making these technologies accessible to students. The second part of the thesis relates to innovative methods for enhancing science education through technology. Traditional teaching methods are dominating science education, but new IT-based approaches provide an opportunity....... However, the lack of foundational technologies, methods, and prediction capabilities form a large barrier towards the transformation to a bio-based society, where products of cell factories are replacing fossil fuels, plastics and traditional chemicals derived from oil. In this thesis we present new...

  8. Multistep carcinogenesis of normal human fibroblasts. Human fibroblasts immortalized by repeated treatment with Co-60 gamma rays were transformed into tumorigenic cells with Ha-ras oncogenes.

    Science.gov (United States)

    Namba, M; Nishitani, K; Fukushima, F; Kimoto, T

    1988-01-01

    Two normal mortal human fibroblast cell strains were transformed into immortal cell lines, SUSM-1 and KMST-6, by treatment with 4-nitroquinoline 1-oxide (4NQO) and Co-60 gamma rays, respectively. These immortalized cell lines showed morphological changes of cells and remarkable chromosome aberrations, but neither of them grew in soft agar or formed tumors in nude mice. The immortal cell line, KMST-6, was then converted into neoplastic cells by treatment with Harvey murine sarcoma virus (Ha-MSV) or the c-Ha-ras oncogene derived from a human lung carcinoma. These neoplastically transformed cells acquired anchorage-independent growth potential and developed tumors when transplanted into nude mice. All the tumors grew progressively without regression until the animals died of tumors. In addition, the tumors were transplantable into other nude mice. Normal human fibroblasts, on the other hand, were not transformed into either immortal or tumorigenic cells by treatment with Ha-MSV or c-Ha-ras alone. Our present data indicate that (1) the chemical carcinogen, 4NQO, or gamma rays worked as an initiator of carcinogenesis in normal human cells, giving rise to immortality, and (2) the ras gene played a role in the progression of the immortally transformed cells to more malignant cells showing anchorage-independent growth and tumorigenicity. In other words, the immortalization process of human cells seems to be a pivotal or rate-limiting step in the carcinogenesis of human cells.

  9. Chronic Exposure to Particulate Nickel Induces Neoplastic Transformation in Human Lung Epithelial Cells

    Directory of Open Access Journals (Sweden)

    Amie L. Holmes

    2013-11-01

    Full Text Available Nickel is a well-known human lung carcinogen with the particulate form being the most potent; however, the carcinogenic mechanism remains largely unknown. Few studies have investigated the genotoxicity and carcinogenicity of nickel in its target cell, human bronchial epithelial cells. Thus, the goal of this study was to investigate the effects of particulate nickel in human lung epithelial cells. We found that nickel subsulfide induced concentration- and time-dependent increases in both cytotoxicity and genotoxicity in human lung epithelial cells (BEP2D. Chronic exposure to nickel subsulfide readily induced cellular transformation, inducing 2.55, 2.9 and 2.35 foci per dish after exposure to 1, 2.5 and 5 μg/cm2 nickel subsulfide, respectively. Sixty-one, 100 and 70 percent of the foci isolated from 1, 2.5, and 5 μg/cm2 nickel subsulfide treatments formed colonies in soft agar and the degree of soft agar colony growth increased in a concentration-dependent manner. Thus, chronic exposure to particulate nickel induces genotoxicity and cellular transformation in human lung epithelial cells.

  10. Cytoskeletal dynamics in interphase, mitosis and cytokinesis analysed through Agrobacterium-mediated transient transformation of tobacco BY-2 cells.

    Science.gov (United States)

    Buschmann, H; Green, P; Sambade, A; Doonan, J H; Lloyd, C W

    2011-04-01

    Transient transformation with Agrobacterium is a widespread tool allowing rapid expression analyses in plants. However, the available methods generate expression in interphase and do not allow the routine analysis of dividing cells. Here, we present a transient transformation method (termed 'TAMBY2') to enable cell biological studies in interphase and cell division. Agrobacterium-mediated transient gene expression in tobacco BY-2 was analysed by Western blotting and quantitative fluorescence microscopy. Time-lapse microscopy of cytoskeletal markers was employed to monitor cell division. Double-labelling in interphase and mitosis enabled localization studies. We found that the transient transformation efficiency was highest when BY-2/Agrobacterium co-cultivation was performed on solid medium. Transformants produced in this way divided at high frequency. We demonstrated the utility of the method by defining the behaviour of a previously uncharacterized microtubule motor, KinG, throughout the cell cycle. Our analyses demonstrated that TAMBY2 provides a flexible tool for the transient transformation of BY-2 with Agrobacterium. Fluorescence double-labelling showed that KinG localizes to microtubules and to F-actin. In interphase, KinG accumulates on microtubule lagging ends, suggesting a minus-end-directed function in vivo. Time-lapse studies of cell division showed that GFP-KinG strongly labels preprophase band and phragmoplast, but not the metaphase spindle. © 2010 The Authors. New Phytologist © 2010 New Phytologist Trust.

  11. Merkel Cell Polyomavirus Small T Antigen Initiates Merkel Cell Carcinoma-like Tumor Development in Mice.

    Science.gov (United States)

    Verhaegen, Monique E; Mangelberger, Doris; Harms, Paul W; Eberl, Markus; Wilbert, Dawn M; Meireles, Julia; Bichakjian, Christopher K; Saunders, Thomas L; Wong, Sunny Y; Dlugosz, Andrzej A

    2017-06-15

    Merkel cell carcinoma (MCC) tumor cells express several markers detected in normal Merkel cells, a nonproliferative population of neuroendocrine cells that arise from epidermis. MCCs frequently contain Merkel cell polyomavirus (MCPyV) DNA and express viral transforming antigens, sT and tLT, but the role of these putative oncogenes in MCC development, and this tumor's cell of origin, are unknown. Using a panel of preterm transgenic mice, we show that epidermis-targeted coexpression of sT and the cell fate-determinant atonal bHLH transcription factor 1 (ATOH1) leads to development of widespread cellular aggregates, with histology and marker expression mimicking that of human intraepidermal MCC. The MCC-like tumor phenotype was dependent on the FBXW7-binding domain of sT, but not the sT-PP2A binding domain. Coexpression of MCPyV tLT did not appreciably alter the phenotype driven by either sT or sT combined with ATOH1. MCPyV sT, when coexpressed with ATOH1, is thus sufficient to initiate development of epidermis-derived MCC-like tumors in mice. Cancer Res; 77(12); 3151-7. ©2017 AACR . ©2017 American Association for Cancer Research.

  12. TGFβR signalling controls CD103+CD11b+ dendritic cell development in the intestine

    NARCIS (Netherlands)

    L.J. Bain (Lisa); Montgomery, J. (J.); C.L. Scott (C.); J.M. Kel (Junda); M.J.H. Girard-Madoux (Mathilde); L. Martens (Liesbet); Zangerle-Murray, T.F.P. (T. F.P.); J.L. Ober-Blöbaum (Julia); D.J. Lindenbergh-Kortleve (Dicky); J.N. Samsom (Janneke); S. Henri (Sandrine); T. Lawrence (Toby); Y. Saeys (Yvan); B. Malissen (Bernard); M. Dalod (Marc); B.E. Clausen (Bjorn); Mowat, A.M. (A. McI.)

    2017-01-01

    textabstractCD103+CD11b+ dendritic cells (DCs) are unique to the intestine, but the factors governing their differentiation are unclear. Here we show that transforming growth factor receptor 1 (TGFβR1) has an indispensable, cell intrinsic role in the development of these cells. Deletion of Tgfbr1

  13. 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

  14. Advances in Maize Transformation Technologies and Development of Transgenic Maize.

    Science.gov (United States)

    Yadava, Pranjal; Abhishek, Alok; Singh, Reeva; Singh, Ishwar; Kaul, Tanushri; Pattanayak, Arunava; Agrawal, Pawan K

    2016-01-01

    Maize is the principal grain crop of the world. It is also the crop where genetic engineering has been employed to a great extent to improve its various traits. The ability to transform maize is a crucial step for application of gene technology in maize improvement. There have been constant improvements in the maize transformation technologies over past several years. The choice of genotype and the explant material to initiate transformation and the different types of media to be used in various stages of tissue culture can have significant impact on the outcomes of the transformation efforts. Various methods of gene transfer, like the particle bombardment, protoplast transformation, Agrobacterium -mediated, in planta transformation, etc., have been tried and improved over years. Similarly, various selection systems for retrieval of the transformants have been attempted. The commercial success of maize transformation and transgenic development is unmatched by any other crop so far. Maize transformation with newer gene editing technologies is opening up a fresh dimension in transformation protocols and work-flows. This review captures the various past and recent facets in improvement in maize transformation technologies and attempts to present a comprehensive updated picture of the current state of the art in this area.

  15. Transforming early childhood education for sustainable development

    African Journals Online (AJOL)

    This paper examined the ways in which early childhood education needs to be transformed for sustainable development. These ways include teaching children environmental security through play, personal hygiene, appropriate waste use and disposal, and nature awareness. It was recommended that early childhood ...

  16. DNA crosslinking and cytotoxicity in normal and transformed human cells treated with antitumor nitrosoureas.

    OpenAIRE

    Erickson, L C; Bradley, M O; Ducore, J M; Ewig, R A; Kohn, K W

    1980-01-01

    Normal (IMR-90) and simian virus 40-transformed (VA-13) human embryo cells were treated with antitumor nitrosoureas, and the effects on cell viability and cell DNA were compared. All six nitrosoureas tested were more toxic to VA-13 cells than to IMR-90 cells as measured by decrease in cell proliferation or in colony formation. The nitrosoureas capable of generating alkylisocyanates produced a smaller difference between the cell types than did derivatives lacking this capacity. DNA damage was ...

  17. Histological transformation after acquired resistance to epidermal growth factor tyrosine kinase inhibitors.

    Science.gov (United States)

    Shao, Yi; Zhong, Dian-Sheng

    2018-04-01

    Non-small-cell lung cancer patients with sensitive epidermal growth factor receptor mutations generally respond well to tyrosine kinase inhibitors (TKIs). However, acquired resistance will eventually develop place after 8-16 months. Several mechanisms contribute to the resistance including T790M mutation, c-Met amplification, epithelial mesenchymal transformation and PIK3CA mutation; however, histological transformation is a rare mechanism. The patterns and mechanisms underlying histological transformation need to be explored. We searched PubMed, EMBASE and search engines Google Scholar, Medical Matrix for literature related to histological transformation. Case reports, cases series, and clinical and basic medical research articles were reviewed. Sixty-one articles were included in this review. Cases of transformation to small-cell lung cancer, squamous cell carcinoma, large-cell neuroendocrine carcinoma and sarcoma after TKI resistance have all been reported. As the clinical course differed dramatically between cases, a new treatment scheme needs to be recruited. The mechanisms underlying histological transformation have not been fully elucidated and probably relate to cancer stem cells, driver genetic alterations under selective pressure or the heterogeneity of the tumor. When TKI resistance develops, we recommend that patients undergo a second biopsy to determine the reason, guide the next treatment and predict the prognosis.

  18. 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

    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...

  19. [Transformation of 2- and 4-cyanopyridines by free and immobilized cells of nitrile-hydrolyzing bacteria].

    Science.gov (United States)

    Maksimova, Iu G; Vasil'ev, D M; Ovechkina, G V; Maksimov, A Iu; Demakov, V A

    2013-01-01

    The transformation dynamics of 2- and 4-cyanopyridines by cells suspended and adsorbed on inorganic carriers has been studied in the Rhodococcus ruber gt 1 strain possessing nitrile hydratase activity and the Pseudomonas fluorescens C2 strain containing nitrilase. It was shown that both nitrile hydratase and nitrilase activities of immobilized cells against 2-cyanopyridine were 1.5-4 times lower compared to 4-cyanopyridine and 1.6-2 times lower than the activities of free cells against 2-cyanpopyridine. The possibility of obtaining isonicotinic acid during the combined conversion of 4-cyanopyridine by a mixed suspension of R. ruber gt 1 cells with a high level of nitrile hydratase activity and R. erythropolis 11-2 cells with a pronounced activity of amidase has been shown. Immobilization of Rhodococcus cells on raw coal and Pseudomonas cells on china clay was shown to yield a heterogeneous biocatalyst for the efficient transformation of cyanopyridines into respective amides and carbonic acids.

  20. Oncogenic transformation of rat lung epithelioid cells by SV40 DNA and restriction enzyme fragments

    International Nuclear Information System (INIS)

    Daya-Grosjean, L.; Lasne, C.; Nardeux, P.; Chouroulinkov, I.; Monier, R.

    1979-01-01

    Rat epithelioid lung cells were transformed with various preparations of SV40 DNA using the Ca 2+ -precipitation technique. The amount of SV40 genetic information integrated into transformed clones was evaluated by DNA-DNA renaturation kinetics. The growth properties on plastic and in soft-agar were examined, as well as the ability to induce tumors in syngeneic newborn animals or in adult nude mice. One particular transformed line, which had received the HpaII/BamHIA (59 per cent) fragment, was found to contain about 3 integrated copies of this fragment per cell and no significant amount of the HpaII/BamHIB (41 per cent fragment). This line which grew to high saturatio densities and efficiently formed clones in low serum on plastic, produced tumors in both syngeneic rats and nude mice. Thus the HpaII/BamHIA fragment, which mainly includes early viral information, was sufficient to impart these properties to rat epithelioid lung cells. (author)

  1. 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.

  2. 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...

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

    International Nuclear Information System (INIS)

    Hume, Stephanie L.; Chiaramonti, Ann N.; Rice, Katherine P.; Schwindt, Rani K.; MacCuspie, Robert I.; Jeerage, Kavita M.

    2015-01-01

    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

  4. 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

  5. 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

    lifespan (fibroblasts, primary human tumour cells) can be mimicked by unknown steps also associated with immortalization (establishment function) and the transformed state of the tumour cells. Another interesting observation were morphological changes of the established and SV40-transformed cells which...

  6. 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

  7. Atypical protein kinase C activity is required for extracellular matrix degradation and invasion by Src-transformed cells.

    Science.gov (United States)

    Rodriguez, Elena M; Dunham, Elizabeth E; Martin, G Steven

    2009-10-01

    Atypical protein kinase C (aPKC) isoforms have been shown to mediate Src-dependent signaling in response to growth factor stimulation. To determine if aPKC activity contributes to the transformed phenotype of cells expressing oncogenic Src, we have examined the activity and function of aPKCs in 3T3 cells expressing viral Src (v-Src). aPKC activity and tyrosine phosphorylation were found to be elevated in some but not all clones of mouse fibroblasts expressing v-Src. aPKC activity was inhibited either by addition of a membrane-permeable pseudosubstrate, by expression of a dominant-negative aPKC, or by RNAi-mediated knockdown of specific aPKC isoforms. aPKC activity contributes to morphological transformation and stress fiber disruption, and is required for migration of Src-transformed cells and for their ability to polarize at the edge of a monolayer. The lambda isoform of aPKC is specifically required for invasion through extracellular matrix in Boyden chamber assays and for degradation of the extracellular matrix in in situ zymography assays. Tyrosine phosphorylation of aPKClambda is required for its ability to promote cell invasion. The defect in invasion upon aPKC inhibition appears to result from a defect in the assembly and/or function of podosomes, invasive adhesions on the ventral surface of the cell that are sites of protease secretion. aPKC was also found to localize to podosomes of v-Src transformed cells, suggesting a direct role for aPKC in podosome assembly and/or function. We conclude that basal or elevated aPKC activity is required for the ability of Src-transformed cells to degrade and invade the extracellular matrix. Copyright 2009 Wiley-Liss, Inc.

  8. Drinking water disinfection byproduct iodoacetic acid induces tumorigenic transformation of NIH3T3 cells.

    Science.gov (United States)

    Wei, Xiao; Wang, Shu; Zheng, Weiwei; Wang, Xia; Liu, Xiaolin; Jiang, Songhui; Pi, Jingbo; Zheng, Yuxin; He, Gengsheng; Qu, Weidong

    2013-06-04

    Iodoacetic acid (IAA) and iodoform (IF) are unregulated iodinated disinfection byproducts (DBPs) found in drinking water. Their presence in the drinking water of China has not been documented. Recently, the carcinogenic potential of IAA and IF has been a concern because of their mutagenicity in bacteria and genotoxicity in mammalian cells. Therefore, we measured their concentrations in Shanghai drinking water and assessed their cytotoxicity, genotoxicity, and ability to transform NIH3T3 cells to tumorigenic lines. The concentrations of IAA and IF in Shanghai drinking water varied between summer and winter with maximum winter levels of 2.18 μg/L IAA and 0.86 μg/L IF. IAA with a lethal concentration 50 (LC50) of 2.77 μM exhibited more potent cytotoxicity in NIH3T3 cells than IF (LC50 = 83.37 μM). IAA, but not IF, induced a concentration-dependent DNA damage measured by γ-H2AX staining and increased tail moment in single-cell gel electrophoresis. Neither IAA nor IF increased micronucleus frequency. Prolonged exposure of NIH3T3 cells to IAA increased the frequencies of transformed cells with anchorage-independent growth and agglutination with concanavalin A. IAA-transformed cells formed aggressive fibrosarcomas after inoculation into Balb/c nude mice. This study demonstrated that IAA has a biological activity that is consistent with a carcinogen and human exposure should be of concern.

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

    Science.gov (United States)

    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.

  10. Navigating Change and Transformation in Collection Development

    Science.gov (United States)

    Kleszynski, Margaret A.

    2012-01-01

    For nearly two decades, librarians have been noting and writing about transformational change in collection development and subsequently predicting future directions for libraries in terms of building digital collections. This paradigm shift caused by the incorporation of more and more electronic resources into existing library collections and…

  11. Properties of HTLV-I transformed CD8+ T-cells in response to HIV-1 infection.

    Science.gov (United States)

    Gulzar, N; Shroff, A; Buberoglu, B; Klonowska, D; Kim, J E; Copeland, K F T

    2010-10-25

    HIV-1 infection studies of primary CD8(+) T-cells are hampered by difficulty in obtaining a significant number of targets for infection and low levels of productive infection. Further, there exists a paucity of CD8-expressing T-cell lines to address questions pertaining to the study of CD8(+) T-cells in the context of HIV-1 infection. In this study, a set of CD8(+) T-cell clones were originated through HTLV-I transformation in vitro, and the properties of these cells were examined. The clones were susceptible to T-cell tropic strains of the virus and exhibited HIV-1 production 20-fold greater than primary CD4(+) T-cells. Productive infection resulted in a decrease in expression of CD8 and CXCR4 molecules on the surface of the CD8(+) T-cell clones and antibodies to these molecules abrogated viral binding and replication. These transformed cells provide an important tool in the study of CD8(+) T-cells and may provide important insights into the mechanism(s) behind HIV-1 induced CD8(+) T-cell dysfunction. Copyright © 2010 Elsevier Inc. All rights reserved.

  12. Chronic occupational exposure to arsenic induces carcinogenic gene signaling networks and neoplastic transformation in human lung epithelial cells

    International Nuclear Information System (INIS)

    Stueckle, Todd A.; Lu, Yongju; Davis, Mary E.; Wang, Liying; Jiang, Bing-Hua; Holaskova, Ida; Schafer, Rosana; Barnett, John B.; Rojanasakul, Yon

    2012-01-01

    Chronic arsenic exposure remains a human health risk; however a clear mode of action to understand gene signaling-driven arsenic carcinogenesis is currently lacking. This study chronically exposed human lung epithelial BEAS-2B cells to low-dose arsenic trioxide to elucidate cancer promoting gene signaling networks associated with arsenic-transformed (B-As) cells. Following a 6 month exposure, exposed cells were assessed for enhanced cell proliferation, colony formation, invasion ability and in vivo tumor formation compared to control cell lines. Collected mRNA was subjected to whole genome expression microarray profiling followed by in silico Ingenuity Pathway Analysis (IPA) to identify lung carcinogenesis modes of action. B-As cells displayed significant increases in proliferation, colony formation and invasion ability compared to BEAS-2B cells. B-As injections into nude mice resulted in development of primary and secondary metastatic tumors. Arsenic exposure resulted in widespread up-regulation of genes associated with mitochondrial metabolism and increased reactive oxygen species protection suggesting mitochondrial dysfunction. Carcinogenic initiation via reactive oxygen species and epigenetic mechanisms was further supported by altered DNA repair, histone, and ROS-sensitive signaling. NF-κB, MAPK and NCOR1 signaling disrupted PPARα/δ-mediated lipid homeostasis. A ‘pro-cancer’ gene signaling network identified increased survival, proliferation, inflammation, metabolism, anti-apoptosis and mobility signaling. IPA-ranked signaling networks identified altered p21, EF1α, Akt, MAPK, and NF-κB signaling networks promoting genetic disorder, altered cell cycle, cancer and changes in nucleic acid and energy metabolism. In conclusion, transformed B-As cells with their whole genome expression profile provide an in vitro arsenic model for future lung cancer signaling research and data for chronic arsenic exposure risk assessment. Highlights: ► Chronic As 2 O 3

  13. Chronic occupational exposure to arsenic induces carcinogenic gene signaling networks and neoplastic transformation in human lung epithelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Stueckle, Todd A., E-mail: tstueckle@hsc.wvu.edu [Department of Basic Pharmaceutical Sciences, West Virginia University, Morgantown, WV 26506 (United States); Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV 26505 (United States); Lu, Yongju, E-mail: yongju6@hotmail.com [Department of Basic Pharmaceutical Sciences, West Virginia University, Morgantown, WV 26506 (United States); Davis, Mary E., E-mail: mdavis@wvu.edu [Department of Physiology, West Virginia University, Morgantown, WV 26506 (United States); Wang, Liying, E-mail: lmw6@cdc.gov [Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV 26505 (United States); Jiang, Bing-Hua, E-mail: bhjiang@jefferson.edu [Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA 19107 (United States); Holaskova, Ida, E-mail: iholaskova@hsc.wvu.edu [Department of Microbiology, Immunology and Cell Biology, West Virginia University, Morgantown, WV 26506 (United States); Schafer, Rosana, E-mail: rschafer@hsc.wvu.edu [Department of Microbiology, Immunology and Cell Biology, West Virginia University, Morgantown, WV 26506 (United States); Barnett, John B., E-mail: jbarnett@hsc.wvu.edu [Department of Microbiology, Immunology and Cell Biology, West Virginia University, Morgantown, WV 26506 (United States); Rojanasakul, Yon, E-mail: yrojan@hsc.wvu.edu [Department of Basic Pharmaceutical Sciences, West Virginia University, Morgantown, WV 26506 (United States)

    2012-06-01

    Chronic arsenic exposure remains a human health risk; however a clear mode of action to understand gene signaling-driven arsenic carcinogenesis is currently lacking. This study chronically exposed human lung epithelial BEAS-2B cells to low-dose arsenic trioxide to elucidate cancer promoting gene signaling networks associated with arsenic-transformed (B-As) cells. Following a 6 month exposure, exposed cells were assessed for enhanced cell proliferation, colony formation, invasion ability and in vivo tumor formation compared to control cell lines. Collected mRNA was subjected to whole genome expression microarray profiling followed by in silico Ingenuity Pathway Analysis (IPA) to identify lung carcinogenesis modes of action. B-As cells displayed significant increases in proliferation, colony formation and invasion ability compared to BEAS-2B cells. B-As injections into nude mice resulted in development of primary and secondary metastatic tumors. Arsenic exposure resulted in widespread up-regulation of genes associated with mitochondrial metabolism and increased reactive oxygen species protection suggesting mitochondrial dysfunction. Carcinogenic initiation via reactive oxygen species and epigenetic mechanisms was further supported by altered DNA repair, histone, and ROS-sensitive signaling. NF-κB, MAPK and NCOR1 signaling disrupted PPARα/δ-mediated lipid homeostasis. A ‘pro-cancer’ gene signaling network identified increased survival, proliferation, inflammation, metabolism, anti-apoptosis and mobility signaling. IPA-ranked signaling networks identified altered p21, EF1α, Akt, MAPK, and NF-κB signaling networks promoting genetic disorder, altered cell cycle, cancer and changes in nucleic acid and energy metabolism. In conclusion, transformed B-As cells with their whole genome expression profile provide an in vitro arsenic model for future lung cancer signaling research and data for chronic arsenic exposure risk assessment. Highlights: ► Chronic As{sub 2}O

  14. Regulation of the O-glycan-type Sialyl-Lewis X (sLex) Bio-synthesis Pathway during Cell Transformation Programs: Epithelial-Mesenchymal Transition (EMT) and Molecular Subtypes in Breast Carcinoma and Human T Cell Activation

    KAUST Repository

    AbuElela, Ayman

    2017-01-01

    During tumor progression and development of distant metastases, a subset of cancer cells undergoes transformation programs, such as epithelial-mesenchymal transition (EMT), to acquire enhanced migratory attributes to commence the metastatic cascade

  15. 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 lymphoblast......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...

  16. HPV-Induced Field Cancerisation: Transformation of Adult Tissue Stem Cell Into Cancer Stem Cell.

    Science.gov (United States)

    Olivero, Carlotta; Lanfredini, Simone; Borgogna, Cinzia; Gariglio, Marisa; Patel, Girish K

    2018-01-01

    Field cancerisation was originally described as a basis for multiple head and neck squamous cell carcinoma (HNSCC) and is a pre-malignant phenomenon that is frequently attributable to oncogenic human papillomavirus (HPV) infection. Our work on β-HPV-induced cutaneous squamous cell carcinomas identified a novel Lrig1+ hair follicle junctional zone keratinocyte stem cell population as the basis for field cancerisation. Herein, we describe the ability for HPV to infect adult tissue stem cells in order to establish persistent infection and induce their proliferation and displacement resulting in field cancerisation. By review of the HPV literature, we reveal how this mechanism is conserved as the basis of field cancerisation across many tissues. New insights have identified the capacity for HPV early region genes to dysregulate adult tissue stem cell self-renewal pathways ensuring that the expanded population preserve its stem cell characteristics beyond the stem cell niche. HPV-infected cells acquire additional transforming mutations that can give rise to intraepithelial neoplasia (IEN), from environmental factors such as sunlight or tobacco induced mutations in skin and oral cavity, respectively. With establishment of IEN, HPV viral replication is sacrificed with loss of the episome, and the tissue is predisposed to multiple cancer stem cell-driven carcinomas.

  17. 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.

  18. Developing a nurse-led clinic using transformational leadership.

    Science.gov (United States)

    Gousy, Mamood; Green, Kim

    2015-03-25

    Nurses are at the forefront of implementing and managing change, given constantly changing healthcare services and the increase in demand for health care. Therefore, it is important to identify the best style of leadership to engage nurses in implementing service-led improvements. This article explores the effects of transformational leadership in bringing about service-led improvements in health care, using the example of setting up a nurse-led acupuncture clinic to optimise the care of patients with chronic pain. Transformational leadership was used throughout the project - from the initial local planning, training and development, through to liaising with the appropriate staff and deciding on an evaluation strategy. Transformational leadership proved to be an effective way to engage and empower nurses and other members of the chronic pain team to enable them to achieve the project aims.

  19. Small cell lung cancer transformation from EGFR-mutated lung adenocarcinoma: A case report and literatures review.

    Science.gov (United States)

    Liu, Yangyang

    2018-06-03

    Epithelial growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) have markedly improved the response of non-small cell lung cancer (NSCLC) with EGFR-mutant patients. However, these patients inevitably come cross acquired resistance to EGFR-TKIs. The transformation of lung adenocarcinoma to small cell lung cancer (SCLC) following treatment with EGFR-TKIs is rare, which leads to resistance to EGFR-TKIs. The present case concerns a case of a 38-year-old man presenting with cough and dyspnea. Radical resection was performed and confirmed an EGFR exon 21 L858R lung adenocarcinoma. However, the patient suffered pleural metastasis after successful treatment with surgery and adjuvant treatment. So, erlotinib was administered with 18 months. Because of enlarged pleural nodule, repeat biopsy identified an SCLC and chemotherapy was started. However, despite the brief success of chemotherapy, our patient suffered brain metastasis. Our case emaphsizes both the profile of transformation from NSCLC to SCLC and the importance of repeat biopsy dealing with drug resistance. We also summarize the clinical characteristics, mechanisms, predictors of SCLC transformation, treatment after transformation and other types of transformation to SCLC.

  20. 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)

    Cleaver, J.E.

    1989-01-01

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    Cleaver, J.E. (Univ. of California, San Francisco (USA))

    1989-01-01

    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.

  2. N6-methyladenosine mediates the cellular proliferation and apoptosis via microRNAs in arsenite-transformed cells.

    Science.gov (United States)

    Gu, Shiyan; Sun, Donglei; Dai, Huangmei; Zhang, Zunzhen

    2018-04-20

    N 6 -methyladenosine (m 6 A) modification is implicated to play an important role in cellular biological processes, but its regulatory mechanisms in arsenite-induced carcinogenesis are largely unknown. Here, human bronchial epithelial (HBE) cells were chronically treated with 2.5 μM arsenite sodium (NaAsO 2 ) for about 13 weeks and these cells were identified with malignant phenotype which was demonstrated by increased levels of cellular proliferation, percentages of plate colony formation and soft agar clone formation, and high potential of resistance to apoptotic induction. Our results firstly demonstrated that m 6 A modification on RNA was significantly increased in arsenite-transformed cells and this modification may be synergistically regulated by methyltransferase-like 3 (METTL3), methyltransferase-like 14 (METTL14), Wilms tumor 1-associated protein (WTAP) and Fat mass and obesity-associated protein (FTO). In addition, knocking down of METTL3 in arsenite-transformed cells can dramatically reverse the malignant phenotype, which was manifested by lower percentages of clone and colony formation as well as higher rates of apoptotic induction. Given the critical roles of miRNAs in cellular proliferation and apoptosis, miRNAs regulated by m 6 A in arsenite-transformed cells were analyzed by Venn diagram and KEGG pathway in this study. The results showed that these m 6 A-mediated miRNAs can regulate pathways which are closely associated with cellular proliferation and apoptosis, implicating that these miRNAs may be the critical bridge by which m 6 A mediates dysregulation of cell survival and apoptosis in arsenite-transformed cells. Taken together, our results firstly demonstrated the significant role of m 6 A in the prevention of tumor occurrence and progression induced by arsenite. Copyright © 2018 Elsevier B.V. All rights reserved.

  3. 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

  4. Regulation of IFN regulatory factor 4 expression in human T cell leukemia virus-I-transformed T cells.

    Science.gov (United States)

    Sharma, Sonia; Grandvaux, Nathalie; Mamane, Yael; Genin, Pierre; Azimi, Nazli; Waldmann, Thomas; Hiscott, John

    2002-09-15

    IFN regulatory factor (IRF)-4 is a lymphoid/myeloid-restricted member of the IRF transcription factor family that plays an essential role in the homeostasis and function of mature lymphocytes. IRF-4 expression is tightly regulated in resting primary T cells and is transiently induced at the mRNA and protein levels after activation by Ag-mimetic stimuli such as TCR cross-linking or treatment with phorbol ester and calcium ionophore (PMA/ionomycin). However, IRF-4 is constitutively upregulated in human T cell leukemia virus type I (HTLV-I) infected T cells as a direct gene target for the HTLV-I Tax oncoprotein. In this study we demonstrate that chronic IRF-4 expression in HTLV-I-infected T lymphocytes is associated with a leukemic phenotype, and we examine the mechanisms by which continuous production of IRF-4 is achieved in HTLV-I-transformed T cells. IRF-4 expression in HTLV-1-infected cells is driven through activation of the NF-kappaB and NF-AT pathways, resulting in the binding of p50, p65, and c-Rel to the kappaB1 element and p50, c-Rel, and NF-ATp to the CD28RE element within the -617 to -209 region of the IRF-4 promoter. Furthermore, mutation of either the kappaB1 or CD28RE sites blocks Tax-mediated transactivation of the human IRF-4 promoter in T cells. These experiments constitute the first detailed analysis of human IRF-4 transcriptional regulation within the context of HTLV-I infection and transformation of CD4(+) T lymphocytes.

  5. Cell transformation assays for prediction of carcinogenic potential: state of the science and future research needs

    Science.gov (United States)

    Creton, Stuart; Aardema, Marilyn J.; Carmichael, Paul L.; Harvey, James S.; Martin, Francis L.; Newbold, Robert F.; O’Donovan, Michael R.; Pant, Kamala; Poth, Albrecht; Sakai, Ayako; Sasaki, Kiyoshi; Scott, Andrew D.; Schechtman, Leonard M.; Shen, Rhine R.; Tanaka, Noriho; Yasaei, Hemad

    2012-01-01

    Cell transformation assays (CTAs) have long been proposed as in vitro methods for the identification of potential chemical carcinogens. Despite showing good correlation with rodent bioassay data, concerns over the subjective nature of using morphological criteria for identifying transformed cells and a lack of understanding of the mechanistic basis of the assays has limited their acceptance for regulatory purposes. However, recent drivers to find alternative carcinogenicity assessment methodologies, such as the Seventh Amendment to the EU Cosmetics Directive, have fuelled renewed interest in CTAs. Research is currently ongoing to improve the objectivity of the assays, reveal the underlying molecular changes leading to transformation and explore the use of novel cell types. The UK NC3Rs held an international workshop in November 2010 to review the current state of the art in this field and provide directions for future research. This paper outlines the key points highlighted at this meeting. PMID:21852270

  6. Prediction of lung cells oncogenic transformation for induced radon progeny alpha particles using sugarscape cellular automata.

    Science.gov (United States)

    Baradaran, Samaneh; Maleknasr, Niaz; Setayeshi, Saeed; Akbari, Mohammad Esmaeil

    2014-01-01

    Alpha particle irradiation from radon progeny is one of the major natural sources of effective dose in the public population. Oncogenic transformation is a biological effectiveness of radon progeny alpha particle hits. The biological effects which has caused by exposure to radon, were the main result of a complex series of physical, chemical, biological and physiological interactions. The cellular and molecular mechanisms for radon-induced carcinogenesis have not been clear yet. Various biological models, including cultured cells and animals, have been found useful for studying the carcinogenesis effects of radon progeny alpha particles. In this paper, sugars cape cellular automata have been presented for computational study of complex biological effect of radon progeny alpha particles in lung bronchial airways. The model has included mechanism of DNA damage, which has been induced alpha particles hits, and then formation of transformation in the lung cells. Biomarkers were an objective measure or evaluation of normal or abnormal biological processes. In the model, the metabolism rate of infected cell has been induced alpha particles traversals, as a biomarker, has been followed to reach oncogenic transformation. The model results have successfully validated in comparison with "in vitro oncogenic transformation data" for C3H 10T1/2 cells. This model has provided an opportunity to study the cellular and molecular changes, at the various stages in radiation carcinogenesis, involving human cells. It has become well known that simulation could be used to investigate complex biomedical systems, in situations where traditional methodologies were difficult or too costly to employ.

  7. Cell surface response of chemically transformed, malignant mouse embryonal fibroblasts and human colon cancer cells to the maturation-promoting agent, N,N-dimethylformamide

    International Nuclear Information System (INIS)

    Marks, M.E.

    1985-01-01

    The lactoperoxidase/ 125 I radioiodination procedure was used to probe the cell surface of normal, nontransformed AKR-2B mouse embryo fibroblasts and malignant, permanently methylcholanthrene-transformed AKR-2B (AKR-MCA) cells to establish the relationship between cell surface changes and transformation/differentiation in this call system. AKR-MCA cells displayed surface alterations secondary to N,N-dimethylformamide (DFM)-promoted differentiation. Growth of AKR-MCA cells in DMF virtually eliminated the 85,000 and 63,000 molecular weight surface proteins susceptible to radioiodination and increased surface material of ∼200,000 molecular weight. Thus, surface profiles of DFM-treated AKR-MCA cells were essentially identical to those of nontransformed AKR-2B cells. Experimentation was extended to a cultured human colon cancer cell line (HCT MOSER). HCT MOSER cells exposed to DMF manifested marked, reversible morphological and surface changes which occurred as a function of time of growth in DMF and DMF concentration. Interestingly, material reactive with anti-fibronectin was found on the surfaces and in the culture medium of DFM-treated HCT MOSER cells

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

    International Nuclear Information System (INIS)

    Todd, P.

    1980-01-01

    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

  9. Quantification of DNA in simple eukaryotic cells using Fourier transform infrared spectroscopy.

    Science.gov (United States)

    Whelan, Donna R; Bambery, Keith R; Puskar, Ljiljana; McNaughton, Don; Wood, Bayden R

    2013-10-01

    A technique capable of detecting and monitoring nucleic acid concentration offers potential in diagnosing cancer and further developing an understanding of the biochemistry of disease. The application of Fourier transform infrared (FTIR) spectroscopy has previously been hindered by the supposed non-Beer-Lambert absorption behavior of DNA in intact cells making elucidation of the DNA bands difficult. We use known composition DNA/hemoglobin standards to successfully estimate the DNA content in avian erythrocyte nuclei (44.2%) and intact erythrocytes (12.8%). Furthermore we demonstrate that the absorption of cellular DNA does follow the Beer-Lambert Law and highlights the role of conformation and hydration in FTIR spectroscopy of biological samples. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Increased radiation-induced transformation in C3H/10T1/2 cells after transfer of an exogenous c-myc gene

    International Nuclear Information System (INIS)

    Sorrentino, V.; Drozdoff, V.; Zeitz, L.; Fleissner, E.

    1987-01-01

    C3H/10T 1/2 cells were infected with a retroviral vector expressing a mouse c-myc oncogene and a drug-selection marker. The resulting cells, morphologically indistinguishable from C3H/10T l/1, displayed a greatly enhanced sensitivity to neoplastic transformation by ionizing radiation or by a chemical carcinogen. Constitutive expression of myc therefore appears to synergize with an initial carcinogenic event, providing a function analogous to a subsequent event that apparently is required for the neoplastic transformation of these cells. This cell system should prove useful in exploring early stages in radiation-induced transformation

  11. A novel cogeneration system: A proton exchange membrane fuel cell coupled to a heat transformer

    International Nuclear Information System (INIS)

    Huicochea, A.; Romero, R.J.; Rivera, W.; Gutierrez-Urueta, G.; Siqueiros, J.; Pilatowsky, I.

    2013-01-01

    This study focuses on the potential of a novel cogeneration system which consists of a 5 kW proton exchange membrane fuel cell (PEMFC) and an absorption heat transformer (AHT). The dissipation heat resulting from the operation of the PEMFC would be used to feed the absorption heat transformer, which is integrated to a water purification system. Therefore, the products of the proposed cogeneration system are heat, electricity and distilled water. The study includes a simulation for the PEMFC as well as experimental results obtained with an experimental AHT facility. Based on the simulation results, experimental tests were performed in order to estimate the performance parameters of the overall system. This is possible due to the matching in power and temperatures between the outlet conditions of the simulated fuel cell and the inlet requirements of the AHT. Experimental coefficients of performance are reported for the AHT as well as the overall cogeneration efficiency for the integrated system. The results show that experimental values of coefficient of performance of the AHT and the overall cogeneration efficiency, can reach up to 0.256 and 0.571, respectively. This represents an increment in 12.4% of efficiency, compared to the fuel cell efficiency working individually. This study shows that the combined use of AHT systems with a PEMFC is possible and it is a very feasible project to be developed in the Centro de Investigación en Energía (Centre of Energy Research), México.

  12. Oncogenic transformation with radiation and chemicals: review

    International Nuclear Information System (INIS)

    Hall, E.J.; Hei, T.K.

    1985-01-01

    Quantitative in vitro assay systems for oncogenic transformation are a powerful research tool. They may be based on short-term cultures of hamster embryo cells, or established cell lines of mouse origin. While X-ray-induced transformation of human cells has been demonstrated, it has proved difficult to develop quantitative assay systems based on cells of human origin. The presently available quantitative assays have two quite distinct basic uses. First, they may be useful to accumulate data which is essentially pragmatic in nature. For example, they may be used to compare and contrast the oncogenic potential of chemotherapeutic agents or hypoxic cell sensitizers used or proposed in the clinic. They may be used to identify compounds that inhibit or suppress the transformation incidence resulting from known oncogenic agents, or they may be used to demonstrate the interaction between two different agents, such as radiation and asbestos. Second, they may prove to be invaluable in the study of the basic mechanisms of carcinogenesis, inasmuch as they represent models of tumourigenesis in which the various steps can be manipulated and modified more readily and in a controlled way. (author)

  13. Development of an Agrobacterium-Mediated Stable Transformation Method for the Sensitive Plant Mimosa pudica

    Science.gov (United States)

    Mano, Hiroaki; Fujii, Tomomi; Sumikawa, Naomi; Hiwatashi, Yuji; Hasebe, Mitsuyasu

    2014-01-01

    The sensitive plant Mimosa pudica has long attracted the interest of researchers due to its spectacular leaf movements in response to touch or other external stimuli. Although various aspects of this seismonastic movement have been elucidated by histological, physiological, biochemical, and behavioral approaches, the lack of reverse genetic tools has hampered the investigation of molecular mechanisms involved in these processes. To overcome this obstacle, we developed an efficient genetic transformation method for M. pudica mediated by Agrobacterium tumefaciens (Agrobacterium). We found that the cotyledonary node explant is suitable for Agrobacterium-mediated transformation because of its high frequency of shoot formation, which was most efficiently induced on medium containing 0.5 µg/ml of a synthetic cytokinin, 6-benzylaminopurine (BAP). Transformation efficiency of cotyledonary node cells was improved from almost 0 to 30.8 positive signals arising from the intron-sGFP reporter gene by using Agrobacterium carrying a super-binary vector pSB111 and stabilizing the pH of the co-cultivation medium with 2-(N-morpholino)ethanesulfonic acid (MES) buffer. Furthermore, treatment of the explants with the detergent Silwet L-77 prior to co-cultivation led to a two-fold increase in the number of transformed shoot buds. Rooting of the regenerated shoots was efficiently induced by cultivation on irrigated vermiculite. The entire procedure for generating transgenic plants achieved a transformation frequency of 18.8%, which is comparable to frequencies obtained for other recalcitrant legumes, such as soybean (Glycine max) and pea (Pisum sativum). The transgene was stably integrated into the host genome and was inherited across generations, without affecting the seismonastic or nyctinastic movements of the plants. This transformation method thus provides an effective genetic tool for studying genes involved in M. pudica movements. PMID:24533121

  14. Development of an Agrobacterium-mediated stable transformation method for the sensitive plant Mimosa pudica.

    Directory of Open Access Journals (Sweden)

    Hiroaki Mano

    Full Text Available The sensitive plant Mimosa pudica has long attracted the interest of researchers due to its spectacular leaf movements in response to touch or other external stimuli. Although various aspects of this seismonastic movement have been elucidated by histological, physiological, biochemical, and behavioral approaches, the lack of reverse genetic tools has hampered the investigation of molecular mechanisms involved in these processes. To overcome this obstacle, we developed an efficient genetic transformation method for M. pudica mediated by Agrobacterium tumefaciens (Agrobacterium. We found that the cotyledonary node explant is suitable for Agrobacterium-mediated transformation because of its high frequency of shoot formation, which was most efficiently induced on medium containing 0.5 µg/ml of a synthetic cytokinin, 6-benzylaminopurine (BAP. Transformation efficiency of cotyledonary node cells was improved from almost 0 to 30.8 positive signals arising from the intron-sGFP reporter gene by using Agrobacterium carrying a super-binary vector pSB111 and stabilizing the pH of the co-cultivation medium with 2-(N-morpholinoethanesulfonic acid (MES buffer. Furthermore, treatment of the explants with the detergent Silwet L-77 prior to co-cultivation led to a two-fold increase in the number of transformed shoot buds. Rooting of the regenerated shoots was efficiently induced by cultivation on irrigated vermiculite. The entire procedure for generating transgenic plants achieved a transformation frequency of 18.8%, which is comparable to frequencies obtained for other recalcitrant legumes, such as soybean (Glycine max and pea (Pisum sativum. The transgene was stably integrated into the host genome and was inherited across generations, without affecting the seismonastic or nyctinastic movements of the plants. This transformation method thus provides an effective genetic tool for studying genes involved in M. pudica movements.

  15. The c-Jun N-terminal kinase pathway is critical for cell transformation by the latent membrane protein 1 of Epstein-Barr virus

    International Nuclear Information System (INIS)

    Kutz, Helmut; Reisbach, Gilbert; Schultheiss, Ute; Kieser, Arnd

    2008-01-01

    The latent membrane protein 1 (LMP1) of Epstein-Barr virus (EBV) transforms cells activating signal transduction pathways such as NF-κB, PI3-kinase, or c-Jun N-terminal kinase (JNK). Here, we investigated the functional role of the LMP1-induced JNK pathway in cell transformation. Expression of a novel dominant-negative JNK1 allele caused a block of proliferation in LMP1-transformed Rat1 fibroblasts. The JNK-specific inhibitor SP600125 reproduced this effect in Rat1-LMP1 cells and efficiently interfered with proliferation of EBV-transformed lymphoblastoid cells (LCLs). Inhibition of the LMP1-induced JNK pathway in LCLs caused the downregulation of c-Jun and Cdc2, the essential G2/M cell cycle kinase, which was accompanied by a cell cycle arrest of LCLs at G2/M phase transition. Moreover, SP600125 retarded tumor growth of LCLs in a xenograft model in SCID mice. Our data support a critical role of the LMP1-induced JNK pathway for proliferation of LMP1-transformed cells and characterize JNK as a potential target for intervention against EBV-induced malignancies

  16. Immunofluorescent staining of nuclear antigen in lymphoid cells transformed by Herpesvirus papio (HVP).

    Science.gov (United States)

    Schmitz, H

    1981-01-01

    An improved fixation method for antigen detection in lymphoblastoid cells is described. Herpesvirus papio nuclear antigen (HUPNA) could be stained in several transformed lymphoid cell lines by anti-complement immunofluorescence (ACIF). Antibody to HUPNA was detected in many human sera containing antibodies to Epstein-Barr virus capsid and nuclear antigen (EBNA). Rheumatoid arthritis sera showed a high incidence of both anti-EBNA and anti-HUPNA antibodies.

  17. Involvement of up-regulated Necl-5/Tage4/PVR/CD155 in the loss of contact inhibition in transformed NIH3T3 cells

    International Nuclear Information System (INIS)

    Minami, Yukiko; Ikeda, Wataru; Kajita, Mihoko; Fujito, Tsutomu; Monden, Morito; Takai, Yoshimi

    2007-01-01

    Normal cells show contact inhibition of cell movement and proliferation, but this is lost following transformation. We found that Necl-5, originally identified as a poliovirus receptor and up-regulated in many cancer cells, enhances growth factor-induced cell movement and proliferation. We showed that when cells contact other cells, Necl-5 interacts in trans with nectin-3 and is removed by endocytosis from the cell surface, resulting in a reduction of cell movement and proliferation. We show here that up-regulation of the gene encoding Necl-5 by the oncogene V12-Ki-Ras causes enhanced cell movement and proliferation. Upon cell-cell contact, de novo synthesis of Necl-5 exceeds the rate of Necl-5 endocytosis, eventually resulting in a net increase in the amount of Necl-5 at the cell surface. In addition, expression of the gene encoding nectin-3 is markedly reduced in transformed cells. Thus, up-regulation of Necl-5 following transformation contributes to the loss of contact inhibition in transformed cells

  18. The oncogenic potential of three different 7, 12-dimethylbenz (a)anthracene transformed C3H/10T1/2 cell clones at various passages and the importance of the mode of immunosuppression

    International Nuclear Information System (INIS)

    Saxholm, H.J.K.

    1979-01-01

    The oncogenic potential of C3H/10T1/2 cells which were transformed in vitro with 7,12-dimethylbenz(a)anthracene is reported. The ability of the cells to grow as malignant tumors in syngeneic immunosuppressed mice was used as parameter for oncogenic potential. Cells of types I, II and III were assayed at several dosage levels, i.e., 10 4 , 10 5 or 10 6 cells per inoculum, with or without immunosuppression by antithymocyte serum globulin fraction. The studies were performed in several strains of host animals, i.e., male and female syngeneic C3H mice supplied by the National Cancer Institute, C3H mice supplied by Charles River and nude, athymic female mice. Morphological transformation preceded oncological transformation, and type I cells could not be established as tumors. Type II and type III cells developed oncogenic potential only after several passages in culture. Oncogenic potential was pronounced in the type III cells, and less strongly expressed in type II cells. Also tested were different methods of immunosuppression of the animal against the expression of the oncogenic potential of DMBA transformed C3H/10T1/2 cells from type II and III clones. Immunosuppression by antithymocyte serum globulin fraction was an effective method of preparing the syngeneic host so that cells with a low oncogenic potential would grow as tumors, whereas total body irradiation was not effective. For cells with a high oncogenic potential both ways of immunosuppression were sufficient. Admixing lethally irradiated cells in the cell inoculum slightly enhanced the tumor development from cells with low oncogenic potential and such addition was clearly effective for cells with a higher oncogenic potential, both for the antibody-treated and for the irradiated series. The findings were reproducible. The study stresses the importance of immunosuppression by antithymocyte globulins for detecting in vitro transformed weakly oncogenic cells. (author)

  19. Transforming Engineering Education - For Innovation and Development

    DEFF Research Database (Denmark)

    Marjoram, Tony

    2013-01-01

    Engineering and technology are of vital importance in innovation, social and economic development in higher and lower income countries. Development is driven by engineering applications and infrastructure, and most innovations derive from engineering. The last 50 years has seen significant change...... of young people in engineering, and the need to develop policy perspectives on the transformation of engineering education....... in knowledge production, dissemination and application, and associated needs for engineering, and yet engineering education has changed little over this period. This paper discusses the important role of problem-based learning and humanitarian engineering in promoting the interest, enrolment and retention...

  20. A comprehensive statistical classifier of foci in the cell transformation assay for carcinogenicity testing.

    Science.gov (United States)

    Callegaro, Giulia; Malkoc, Kasja; Corvi, Raffaella; Urani, Chiara; Stefanini, Federico M

    2017-12-01

    The identification of the carcinogenic risk of chemicals is currently mainly based on animal studies. The in vitro Cell Transformation Assays (CTAs) are a promising alternative to be considered in an integrated approach. CTAs measure the induction of foci of transformed cells. CTAs model key stages of the in vivo neoplastic process and are able to detect both genotoxic and some non-genotoxic compounds, being the only in vitro method able to deal with the latter. Despite their favorable features, CTAs can be further improved, especially reducing the possible subjectivity arising from the last phase of the protocol, namely visual scoring of foci using coded morphological features. By taking advantage of digital image analysis, the aim of our work is to translate morphological features into statistical descriptors of foci images, and to use them to mimic the classification performances of the visual scorer to discriminate between transformed and non-transformed foci. Here we present a classifier based on five descriptors trained on a dataset of 1364 foci, obtained with different compounds and concentrations. Our classifier showed accuracy, sensitivity and specificity equal to 0.77 and an area under the curve (AUC) of 0.84. The presented classifier outperforms a previously published model. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. The Transformation of International NGOs and Their Impact on Development Aid

    Directory of Open Access Journals (Sweden)

    Thomas Richard Davies

    2012-03-01

    Full Text Available Published by Palgrave MacmillanInternational non-governmental organisations (INGOs are among the key actors in the transformation of development as a global public policy issue in the post-Cold War era. This chapter explores how in the past two decades INGOs concerned with development have transformed their structures and practices as well as development discourse. The author shows how development INGOs have globalised, in terms of both the formation of international confederations and the collaboration of multiple INGOs in global coalitions. A key development has been the erosion of the apparent North–South divide among development INGOs, with INGOs that originated in donor countries reforming their structures to give a greater voice to their affiliates in recipient countries, and organisations that originated in developing countries forming affiliates in developed countries. The reorientation of INGO advocacy from states toward intergovernmental and corporate actors is also explored, as is the creation of new forms of partnerships with both governmental and private actors. The chapter addresses how development INGOs have attempted to respond to critiques of their accountability and legitimacy through reforms such as the International NGO Charter on Accountability, while the conclusion explores the limitations of the transformations of development INGOs, and the challenges that these new configurations pose.

  2. Transformation of medicinal plants using Agrobacterium tumefaciens

    Directory of Open Access Journals (Sweden)

    Katarzyna Bandurska

    2016-12-01

    Full Text Available For many years attempts are made to develop efficient methods for transformation of medicinal plants via Agrobacterium tumefaciens. It is a soil bacteria which possess a natural ability to infect plants in places of injures which results in arise of cancerous growths (crown gall. This is possible thanks a transfer of fragment of Ti plasmid into plant cells and stable integration with a plant genome. Efficiency of medicinal plant transformation depends on many factors for example: Agrobacterium strain, methods and procedures of transformation as well as on plant species, type and age of the explants and regeneration conditions. The main goal of plant transformation is to increase the amount of naturally occurring bioactive compounds and the production of biopharmaceuticals. Genetic plant transformation via bacteria of the genus Agrobacterium is a complex process which requires detailed analysis of incorporated transgene expression and occurs only in the case when the plant cell acquires the ability to regenerate. In many cases, the regeneration efficiency observed in medicinal plants are inefficient after applied transformation procedures. To date there have been attempts of genetic transformation by using A. tumefaciens of medicinal plants belonging to the families: Apocynaceae, Araceae, Araliaceae, Asphodelaceae, Asteraceae, Begoniaceae, Crassulaceae, Fabaceae, Lamiaceae, Linaceae, Papaveraceae, Plantaginaceae, Scrophulariaceae and Solanaceae.

  3. Transformation of medicinal plants using Agrobacterium tumefaciens.

    Science.gov (United States)

    Bandurska, Katarzyna; Berdowska, Agnieszka; Król, Małgorzata

    2016-12-20

    For many years attempts are made to develop efficient methods for transformation of medicinal plants via Agrobacterium tumefaciens. It is a soil bacteria which possess a natural ability to infect plants in places of injures which results in arise of cancerous growths (crown gall). This is possible thanks a transfer of fragment of Ti plasmid into plant cells and stable integration with a plant genome. Efficiency of medicinal plant transformation depends on many factors for example: Agrobacterium strain, methods and procedures of transformation as well as on plant species, type and age of the explants and regeneration conditions. The main goal of plant transformation is to increase the amount of naturally occurring bioactive compounds and the production of biopharmaceuticals. Genetic plant transformation via bacteria of the genus Agrobacterium is a complex process which requires detailed analysis of incorporated transgene expression and occurs only in the case when the plant cell acquires the ability to regenerate. In many cases, the regeneration efficiency observed in medicinal plants are inefficient after applied transformation procedures. To date there have been attempts of genetic transformation by using A. tumefaciens of medicinal plants belonging to the families: Apocynaceae, Araceae, Araliaceae, Asphodelaceae, Asteraceae, Begoniaceae, Crassulaceae, Fabaceae, Lamiaceae, Linaceae, Papaveraceae, Plantaginaceae, Scrophulariaceae and Solanaceae.

  4. 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

    . A subclone of the cells irradiated with 2.5 Gy of gamma-rays formed tumors after implantation to severe combined immunodeficiency mice. During the process of transformation, the cells showed accelerated telomere shortening, increased levels of anaphase bridges and a shift from balanced to unbalanced...

  5. No activation of new initiation points for deoxyribonucleic acid replication in BALB/c 3T3 cells transformed by Kirsten sarcoma virus

    International Nuclear Information System (INIS)

    Oppenheim, A.; Horowitz, A.T.

    1981-01-01

    BALB/c 3T3 cells were transformed by Kirsten sarcoma virus, and five clones were isolated in soft agar. Average replicon sizes of the transformed cell lines were stimated by the method of fiber-autoradiography and found to be the same size as the nontransformed 3T3 cells, analyzed in parallel. The results indicate that, unlike simian virus 40 and Epstein-Barr virus, Kirsten sarcoma virus does not activate new initiation points for cellular deoxyribonucleic acid replication in murine sarcome virus-transformed BALB/c 3T3 cells

  6. Identification of Proteins Related to Epigenetic Regulation in the Malignant Transformation of Aberrant Karyotypic Human Embryonic Stem Cells by Quantitative Proteomics

    Science.gov (United States)

    Sun, Yi; Yang, Yixuan; Zeng, Sicong; Tan, Yueqiu; Lu, Guangxiu; Lin, Ge

    2014-01-01

    Previous reports have demonstrated that human embryonic stem cells (hESCs) tend to develop genomic alterations and progress to a malignant state during long-term in vitro culture. This raises concerns of the clinical safety in using cultured hESCs. However, transformed hESCs might serve as an excellent model to determine the process of embryonic stem cell transition. In this study, ITRAQ-based tandem mass spectrometry was used to quantify normal and aberrant karyotypic hESCs proteins from simple to more complex karyotypic abnormalities. We identified and quantified 2583 proteins, and found that the expression levels of 316 proteins that represented at least 23 functional molecular groups were significantly different in both normal and abnormal hESCs. Dysregulated protein expression in epigenetic regulation was further verified in six pairs of hESC lines in early and late passage. In summary, this study is the first large-scale quantitative proteomic analysis of the malignant transformation of aberrant karyotypic hESCs. The data generated should serve as a useful reference of stem cell-derived tumor progression. Increased expression of both HDAC2 and CTNNB1 are detected as early as the pre-neoplastic stage, and might serve as prognostic markers in the malignant transformation of hESCs. PMID:24465727

  7. The Role of Transformational Learning in Women's Leadership Development

    Science.gov (United States)

    Suby-Long, Sallie

    2012-01-01

    Based on the theory of transformational learning, the purpose of this study was to conduct survey research with women graduates of two community-based leadership development programs to determine what characteristics describe transformational learning among women participants and to identify what learning activities and experiences may foster…

  8. Suppression of alkylating agent induced cell transformation and gastric ulceration by low-dose alkylating agent pretreatment

    International Nuclear Information System (INIS)

    Onodera, Akira; Kawai, Yuichi; Kashimura, Asako; Ogita, Fumiya; Tsutsumi, Yasuo; Itoh, Norio

    2013-01-01

    Highlights: •Low-dose MNNG pretreatment suppresses high-dose MNNG induced in vitro transformation. •Gastric ulcers induced by high-dose MNNG decreased after low-dose MNNG pretreatment. •Efficacy of low-dose MNNG related to resistance of mutation and oxidative stress. -- Abstract: Exposure to mild stress by chemicals and radiation causes DNA damage and leads to acquired stress resistance. Although the linear no-threshold (LNT) model of safety assessment assumes risk from any dose, evidence from radiological research demonstrates a conflicting hormetic phenomenon known as the hormesis effect. However, the mechanisms underlying radiation hormesis have not yet been clarified, and little is known about the effects of low doses of chemical carcinogens. We analyzed the efficacy of pretreatment with low doses of the alkylating agent N-methyl-N′-nitro-N-nitrosoguanidine (MNNG) on the subsequent induction of cell transformation and gastric ulceration by high-dose MNNG. We used an in vitro Balb/3T3 A31-1-1 cell transformation test and monitored the formation of gastric ulcers in 5-week-old male ICR mice that were administered MNNG in drinking water. The treatment concentrations of MNNG were determined by the cell survival rate and past reports. For low-dose in vitro and in vivo experiments, MNNG was used at 0.028 μM, and 2.8 μg/mL, respectively. The frequency of cell transformation induced by 10 μm MNNG was decreased by low-dose MNNG pretreatment to levels similar to that of spontaneous transformation. In addition, reactive oxygen species (ROS) and mutation frequencies induced by 10 μm MNNG were decreased by low-dose MNNG pretreatment. Importantly, low-dose MNNG pretreatment had no effect on cell proliferation. In vivo studies showed that the number of gastric ulcers induced by 1 mg/mL MNNG decreased after low-dose MNNG pretreatment. These data indicate that low-dose pretreatment with carcinogens may play a beneficial role in the prevention of chemical toxicity

  9. Suppression of alkylating agent induced cell transformation and gastric ulceration by low-dose alkylating agent pretreatment

    Energy Technology Data Exchange (ETDEWEB)

    Onodera, Akira, E-mail: onodera@pharm.kobegakuin.ac.jp [Department of Toxicology, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamada-oka, Suita, Osaka 565-0871 (Japan); Department of Pharmaceutical Sciences, Kobegakuin University, 1-1-3 Minatojima, Chuo-ku, Kobe 650-8586 (Japan); Kawai, Yuichi [Department of Pharmaceutical Sciences, Kobegakuin University, 1-1-3 Minatojima, Chuo-ku, Kobe 650-8586 (Japan); Kashimura, Asako; Ogita, Fumiya; Tsutsumi, Yasuo; Itoh, Norio [Department of Toxicology, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamada-oka, Suita, Osaka 565-0871 (Japan)

    2013-06-14

    Highlights: •Low-dose MNNG pretreatment suppresses high-dose MNNG induced in vitro transformation. •Gastric ulcers induced by high-dose MNNG decreased after low-dose MNNG pretreatment. •Efficacy of low-dose MNNG related to resistance of mutation and oxidative stress. -- Abstract: Exposure to mild stress by chemicals and radiation causes DNA damage and leads to acquired stress resistance. Although the linear no-threshold (LNT) model of safety assessment assumes risk from any dose, evidence from radiological research demonstrates a conflicting hormetic phenomenon known as the hormesis effect. However, the mechanisms underlying radiation hormesis have not yet been clarified, and little is known about the effects of low doses of chemical carcinogens. We analyzed the efficacy of pretreatment with low doses of the alkylating agent N-methyl-N′-nitro-N-nitrosoguanidine (MNNG) on the subsequent induction of cell transformation and gastric ulceration by high-dose MNNG. We used an in vitro Balb/3T3 A31-1-1 cell transformation test and monitored the formation of gastric ulcers in 5-week-old male ICR mice that were administered MNNG in drinking water. The treatment concentrations of MNNG were determined by the cell survival rate and past reports. For low-dose in vitro and in vivo experiments, MNNG was used at 0.028 μM, and 2.8 μg/mL, respectively. The frequency of cell transformation induced by 10 μm MNNG was decreased by low-dose MNNG pretreatment to levels similar to that of spontaneous transformation. In addition, reactive oxygen species (ROS) and mutation frequencies induced by 10 μm MNNG were decreased by low-dose MNNG pretreatment. Importantly, low-dose MNNG pretreatment had no effect on cell proliferation. In vivo studies showed that the number of gastric ulcers induced by 1 mg/mL MNNG decreased after low-dose MNNG pretreatment. These data indicate that low-dose pretreatment with carcinogens may play a beneficial role in the prevention of chemical toxicity

  10. Intake of Boron, Cadmium, and Molybdenum enhances rat thyroid cell transformation.

    Science.gov (United States)

    Luca, Emilia; Fici, Laura; Ronchi, Anna; Marandino, Ferdinando; Rossi, Esther Diana; Caristo, Maria Emiliana; Malandrino, Pasqualino; Russo, Marco; Pontecorvi, Alfredo; Vigneri, Riccardo; Moretti, Fabiola

    2017-06-02

    Epidemiologic data in volcanic areas suggest that environmental factors might be involved in the increase of thyroid cancer (TC) incidence. Recent reports indicate that several heavy metals and metalloids are increased in volcanic areas. This study aims to evaluate the combined effect of three of these elements Boron (B), Cadmium (Cd), and Molybdenum (Mo) - all increased in the volcanic area of Mt. Etna, in Italy - on thyroid tumorigenesis in the rat. Female Wistar rats prone to develop thyroid tumors by low-iodine diet and methimazole treatment received ad libitum drinking water supplemented with B, Cd, and Mo at concentrations in the range found in the urine samples of residents of the volcanic area. At 5 and 10 months animals were euthanized, and their thyroid analysed. Statistical analysis was performed with a 2-way unpaired t-test. No toxic effect of the three elements on the growth of the animals was observed. A significant increase of histological features of transformation was observed in thyroid follicular cells of rats treated with B, Cd, and Mo compared with those of control group. These abnormalities were associated with decreased iodine content in the thyroid. This study provides the evidence that slightly increased environmental concentrations of B, Cd, and Mo can accelerate the appearance of transformation marks in the thyroid gland of hypothyroid rats.

  11. Caveolin-1 down-regulation is required for Wnt5a-Frizzled 2 signalling in Ha-RasV12 -induced cell transformation.

    Science.gov (United States)

    Lin, Hsiu-Kuan; Lin, Hsi-Hui; Chiou, Yu-Wei; Wu, Ching-Lung; Chiu, Wen-Tai; Tang, Ming-Jer

    2018-05-01

    Caveolin-1 (Cav1) is down-regulated during MK4 (MDCK cells harbouring inducible Ha-Ras V12 gene) transformation by Ha-Ras V12 . Cav1 overexpression abrogates the Ha-Ras V12 -driven transformation of MK4 cells; however, the targeted down-regulation of Cav1 is not sufficient to mimic this transformation. Cav1-silenced cells, including MK4/shCav1 cells and MDCK/shCav1 cells, showed an increased cell area and discontinuous junction-related proteins staining. Cellular and mechanical transformations were completed when MDCK/shCav1 cells were treated with medium conditioned by MK4 cells treated with IPTG (MK4+I-CM) but not with medium conditioned by MK4 cells. Nanoparticle tracking analysis showed that Ha-Ras V12 -inducing MK4 cells increased exosome-like microvesicles release compared with their normal counterparts. The cellular and mechanical transformation activities of MK4+I-CM were abolished after heat treatment and exosome depletion and were copied by exosomes derived from MK4+I-CM (MK4+I-EXs). Wnt5a, a downstream product of Ha-Ras V12 , was markedly secreted by MK4+I-CM and MK4+I-EXs. Suppression of Wnt5a expression and secretion using the porcupine inhibitor C59 or Wnt5a siRNA inhibited the Ha-Ras V12 - and MK4+I-CM-induced transformation of MK4 cells and MDCK/shCav1 cells, respectively. Cav1 down-regulation, either by Ha-Ras V12 or targeted shRNA, increased frizzled-2 (Fzd2) protein levels without affecting its mRNA levels, suggesting a novel role of Cav1 in negatively regulating Fzd2 expression. Additionally, silencing Cav1 facilitated the internalization of MK4+I-EXs in MDCK cells. These data suggest that Cav1-dependent repression of Fzd2 and exosome uptake is potentially relevant to its antitransformation activity, which hinders the activation of Ha-Ras V12 -Wnt5a-Stat3 pathway. Altogether, these results suggest that both decreasing Cav1 and increasing exosomal Wnt5a must be implemented during Ha-Ras V12 -driven cell transformation. © 2018 The Authors

  12. Myb proteins: angels and demons in normal and transformed cells.

    Science.gov (United States)

    Zhou, Ye; Ness, Scott A

    2011-01-01

    A key regulator of proliferation, differentiation and cell fate, the c-Myb transcription factor regulates the expression of hundreds of genes and is in turn regulated by numerous pathways and protein interactions. However, the most unique feature of c-Myb is that it can be converted into an oncogenic transforming protein through a few mutations that completely change its activity and specificity. The c-Myb protein is a myriad of interactions and activities rolled up in a protein that controls proliferation and differentiation in many different cell types. Here we discuss the background and recent progress that have led to a better understanding of this complex protein, and outline the questions that have yet to be answered.

  13. Timing of the steps in transformation of C3H 10T1/2 cells by X-irradiation

    International Nuclear Information System (INIS)

    Kennedy, A.R.; Cairns, J.; Little, J.B.

    1984-01-01

    Transformation of cells in culture by chemical carcinogens or X-rays seems to require at least two steps. The initial step is a frequent event; for example, after transient exposure to either methylcholanthrene or X-rays. It has been hypothesized that the second step behaves like a spontaneous mutation in having a constant but small probability of occurring each time an initiated cell divides. We show here that the clone size distribution of transformed cells in growing cultures initiated by X-rays, is, indeed, exactly what would be expected on that hypothesis. (author)

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

    International Nuclear Information System (INIS)

    Servomaa, K.

    1991-04-01

    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, 95 Zr, 103 Ru, 106 Ru, 141 Ce, and 144 Ce. 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

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

    International Nuclear Information System (INIS)

    Zhang, Jingjie; Ouyang, Weiming; Li, Jingxia; Zhang, Dongyun; Yu, Yonghui; Wang, York; Li, Xuejun; Huang, Chuanshu

    2012-01-01

    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.

  16. Structural requirements for cub domain containing protein 1 (CDCP1 and Src dependent cell transformation.

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    Gwendlyn Kollmorgen

    Full Text Available Cub domain containing protein 1 (CDCP1 is strongly expressed in tumors derived from lung, colon, ovary, or kidney. It is a membrane protein that is phosphorylated and then bound by Src family kinases. Although expression and phosphorylation of CDCP1 have been investigated in many tumor cell lines, the CDCP1 features responsible for transformation have not been fully evaluated. This is in part due to the lack of an experimental system in which cellular transformation depends on expression of exogenous CDCP1 and Src. Here we use retrovirus mediated co-overexpression of c-Src and CDCP1 to induce focus formation of NIH3T3 cells. Employing different mutants of CDCP1 we show that for a full transformation capacity, the intact amino- and carboxy-termini of CDCP1 are essential. Mutation of any of the core intracellular tyrosine residues (Y734, Y743, or Y762 abolished transformation, and mutation of a palmitoylation motif (C689,690G strongly reduced it. Src kinase binding to CDCP1 was not required since Src with a defective SH2 domain generated even more CDCP1 dependent foci whereas Src myristoylation was necessary. Taken together, the focus formation assay allowed us to define structural requirements of CDCP1/Src dependent transformation and to characterize the interaction of CDCP1 and Src.

  17. Effects of the combinations of caffeine with 137Cs-gamma rays or tritiated water on the proliferation and malignant transformation CHL-1 cells

    International Nuclear Information System (INIS)

    Zou Shuai; Wang Shoufang

    1989-01-01

    The effects of the combinations of caffeine with 137 Cs-gamma rays or tritiated water on the proliferation and malignant transformation in vitro in CHL-1 cells were observed in experiments. At the concentrations of caffeine from 1 mmol/L to 2 mmol/L, the dose ranges of 137 Cs-gamma rays from 0.837 Gy and to 2.51 Gy and of tritium-beta radiation from 0.837 Gy to 0.528 Gy, the cell proliferation of CHL-1 cells was found to be inbigited when cells were exposed to caffeine, gamma and beta radiations, respectively, as well as when they were exposed to various combinations of caffeine with the two latters. The degree of inhibition of cell proliferation was dependent upon the concentration of caffeine and on the doses of radiation. In the transformation experiments, cell malignant transformation rates for all treated groups were higher than that for contol group and the rates for irradiated plus caffeine-treated groups were higher than those for corresponding single-agent-treated ones. After the subcutaneous injection of transformed cells into irradiated mice, tumours in size of about 2 mm 3 were found in some animals and the tumour cells were identical with in-vitro-transformed CHL-1 cells histopathologically

  18. Cell-cell adhesion mediated by binding of membrane-anchored transforming growth factor α to epidermal growth factor receptors promotes cell proliferation

    International Nuclear Information System (INIS)

    Anklesaria, P.; Greenberger, J.S.; Teixido, J.; Laiho, M.; Massague, J.; Pierce, J.H.

    1990-01-01

    The precursor for transforming growth factor α, pro-TGF-α, is a cell surface glycoprotein that can establish contact with epidermal growth factor (EGF) receptors on adjacent cells. To examine whether the pro-TGF-α/EGF receptor pair can simultaneously mediate cell adhesion and promote cell proliferation, the authors have expressed pro-TGF-α in a bone marrow stromal cell line labeled with [ 35 S] cysteine. Expression of pro-TGF-α allows these cells to support long-term attachment of an EGF/interleukin-3-dependent hematopoietic progenitor cell line that expresses EGF receptors but is unable to adhere to normal stroma. This interaction is inhibited by soluble EGF receptor ligands. Further, the hematopoietic progenitor cells replicate their DNA while they are attached to the stromal cell layer and become foci of sustained cell proliferation. Thus, pro-TGF-α and the EGF receptor can function as mediators of intercellular adhesion and this interaction may promote a mitogenic response. They propose the term juxtacrine to designate this form of stimulation between adjacent cells

  19. Isorhapontigenin (ISO) inhibited cell transformation by inducing G0/G1 phase arrest via increasing MKP-1 mRNA Stability.

    Science.gov (United States)

    Gao, Guangxun; Chen, Liang; Li, Jingxia; Zhang, Dongyun; Fang, Yong; Huang, Haishan; Chen, Xiequn; Huang, Chuanshu

    2014-05-15

    The cancer chemopreventive property of Chinese herb new isolate isorhapontigenin (ISO) and mechanisms underlying its activity have never been explored. Here we demonstrated that ISO treatment with various concentrations for 3 weeks could dramatically inhibit TPA/EGF-induced cell transformation of Cl41 cells in Soft Agar assay, whereas co-incubation of cells with ISO at the same concentrations could elicit G0/G1 cell-cycle arrest without redundant cytotoxic effects on non-transformed cells. Further studies showed that ISO treatment resulted in cyclin D1 downregulation in dose- and time-dependent manner. Our results indicated that ISO regulated cyclin D1 at transcription level via targeting JNK/C-Jun/AP-1 activation. Moreover, we found that ISO-inhibited JNK/C-Jun/AP-1 activation was mediated by both upregulation of MKP-1 expression through increasing its mRNA stability and deactivating MKK7. Most importantly, MKP-1 knockdown could attenuate ISO-mediated suppression of JNK/C-Jun activation and cyclin D1 expression, as well as G0/G1 cell cycle arrest and cell transformation inhibition, while ectopic expression of FLAG-cyclin D1 T286A mutant also reversed ISO-induced G0/G1 cell-cycle arrest and inhibition of cell transformation. Our results demonstrated that ISO is a promising chemopreventive agent via upregulating mkp-1 mRNA stability, which is distinct from its cancer therapeutic effect with downregulation of XIAP and cyclin D1 expression.

  20. Follicular lymphomas and their transformation: Past and current research.

    Science.gov (United States)

    Mendez, Miriam; Torrente, Maria; Provencio, Mariano

    2017-06-01

    Follicular lymphoma (FL) is the second most common type of non-Hodgkin lymphoma (NHL). Histological transformation (HT) refers to the evolution of a clinically indolent NHL to a clinically aggressive one, defined as those lymphomas in which survival is limited to a few months when untreated. Areas covered: HT is associated with rapid progression of lymphadenopathy, infiltration of extranodal sites, development of systemic symptoms, and elevated serum level of lactate dehydrogenase (LDH). It is frequently related to a poor prognosis, and the median survival after transformation is less than 2 years. Transformation to diffuse large B cell lymphoma (DLBCL) in patients with FL occurs at an annual rate of approximately 3% for the first 15 years, after which the risk of HT falls for reasons that remain unclear. Expert commentary: Although it has long been assumed that transformation reflects the emergence of an aggressive subclone of cells from the primary FL, recent studies suggest that FL transformation might also arise by divergent evolution from a more immature common progenitor cell. Studies on genomic changes and DNA sequencing have shed some light onto the process of transformation. Nowadays, we know that HT is a complex process where several molecular pathways are involved.

  1. 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.

  2. Exome Sequencing of Bilateral Testicular Germ Cell Tumors Suggests Independent Development Lineages

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    Sigmund Brabrand

    2015-02-01

    Full Text Available Intratubular germ cell neoplasia, the precursor of testicular germ cell tumors (TGCTs, is hypothesized to arise during embryogenesis from developmentally arrested primordial germ cells (PGCs or gonocytes. In early embryonal life, the PGCs migrate from the yolk sac to the dorsal body wall where the cell population separates before colonizing the genital ridges. However, whether the malignant transformation takes place before or after this separation is controversial. We have explored the somatic exome-wide mutational spectra of bilateral TGCT to provide novel insight into the in utero critical time frame of malignant transformation and TGCT pathogenesis. Exome sequencing was performed in five patients with bilateral TGCT (eight tumors, of these three patients in whom both tumors were available (six tumors and two patients each with only one available tumor (two tumors. Selected loci were explored by Sanger sequencing in 71 patients with bilateral TGCT. From the exome-wide mutational spectra, no identical mutations in any of the three bilateral tumor pairs were identified. Exome sequencing of all eight tumors revealed 87 somatic non-synonymous mutations (median 10 per tumor; range 5-21, some in already known cancer genes such as CIITA, NEB, platelet-derived growth factor receptor α (PDGFRA, and WHSC1. SUPT6H was found recurrently mutated in two tumors. We suggest independent development lineages of bilateral TGCT. Thus, malignant transformation into intratubular germ cell neoplasia is likely to occur after the migration of PGCs. We reveal possible drivers of TGCT pathogenesis, such as mutated PDGFRA, potentially with therapeutic implications for TGCT patients.

  3. 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)

    Kugel, C.

    2001-12-01

    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

  4. Directly Transforming PCR-Amplified DNA Fragments into Plant Cells Is a Versatile System That Facilitates the Transient Expression Assay

    Science.gov (United States)

    Lu, Yuming; Chen, Xi; Wu, Yuxuan; Wang, Yanping; He, Yuqing; Wu, Yan

    2013-01-01

    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. PMID:23468926

  5. 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.

  6. The Role of Titanium Surface Microtopography on Adhesion, Proliferation, Transformation, and Matrix Deposition of Corneal Cells.

    Science.gov (United States)

    Zhou, Chengxin; Lei, Fengyang; Chodosh, James; Paschalis, Eleftherios I

    2016-04-01

    Titanium (Ti) is an excellent implantable biomaterial that can be further enhanced by surface topography optimization. Despite numerous data from orthopedics and dentistry, the effect of Ti surface topography on ocular cells is still poorly understood. In light of the recent adaptation of Ti in the Boston Keratoprosthesis artificial cornea, we attempted to perform an extended evaluation of the effect of Ti surface topography on corneal cell adhesion, proliferation, cytotoxicity, transformation, and matrix deposition. Different surface topographies were generated on medical grade Ti-6Al-4V-ELI (extra-low interstitial), with linearly increased roughness (polished to grit blasted). Biological response was evaluated in vitro using human corneal limbal epithelial (HCLE) cells, stromal fibroblasts (HCF), and endothelial cells (HCEnC). None of the Ti surface topographies caused cytotoxicity to any of the three corneal cell types. However, rough Ti surface inhibited HCLE and HCF cell adhesion and proliferation, while HCEnC proliferation was unaffected. Long-term experiments with HCF revealed that rough Ti surface with R(a) (the arithmetic average of the profile height from the mean line) ≥ 1.15 μm suppressed HCF focal adhesion kinase phosphorylation, changed fibroblast morphology, and caused less aligned and reduced deposition of collagen matrix as compared to smooth Ti (R(a) ≤ 0.08 μm). In the presence of transforming growth factor β1 (TGFβ1) stimulation, rough Ti inhibited alpha-smooth muscle actin (α-SMA) expression and collagen deposition, leading to decreased myofibroblast transformation and disorganization of the collagen fibrils as compared to smooth Ti. This study suggests that Ti surface topography regulates corneal cell behavior in a tissue-dependent manner that varies across the corneal strata. Contrary to the accepted paradigm, smooth surface topography can enhance cell adhesion and proliferation and increase matrix deposition by corneal cells.

  7. In vitro transformation of primary cultures of neonatal BALB/c mouse epidermal cells with ultraviolet-B radiation

    International Nuclear Information System (INIS)

    Ananthaswamy, H.N.; Kripke, M.L.

    1981-01-01

    Primary epidermal cultures from neonatal BALB/c mice were used to study the carcinogenic effects of ultraviolet radiation in vitro. These cultures were irradiated once through a Falcon plastic dish cover with an FS40 sunlamp [ultraviolet B, lambda approximately 290 to 400 nm] for various lengths of time and maintained for 8 to 12 weeks without subculturing. During this period, most of the cells in the untreated control showed signs of morphological differentiation and eventually died. The cultures irradiated with ultraviolet B radiation also behaved in the same manner except that, in some dishes, small populations of surviving cells began to proliferate and developed into morphologically distinct foci. Seven long-term cell lines were derived from these ultraviolet-irradiated primary epidermal cell cultures. Six of these cell lines produced tumors when injected s.c. into normal and/or immunosuppressed syngeneic recipients. These tumorigenic cell lines lacked definitive characteristics of differentiated epidermal cells, but the cells possessed intermediate junctions, suggesting that they were of epithelial origin. Some of these in vitro-transformed cell lines appeared to be highly antigenic inasmuch as they grew preferentially in immunosuppressed BALB/c mice as compared to their growth in normal syngeneic recipients

  8. Genetic transformation of deciduous fruit trees conferring resistance against diseases

    International Nuclear Information System (INIS)

    Mansvelt, E.L.; Glyn-Woods, T.; Watts, L.; Rabie, A.; Appel, M.; Bellstedt, D.U.

    1998-01-01

    Long breeding cycles make cultivar development a lengthy process in deciduous fruit species. Gene transfer is, accordingly, a goal with significant commercial value. In many plant species, especially in woody plants, a prerequisite for genetic engineering is the ability to regenerate plants from transformed cells. Development of single cell regeneration is the first step towards exploration of gene transfer techniques. In this investigation media for plum and apple leaf disk regeneration were developed. Transformation experiments were performed. The vector EHA105 containing the gus-intron gene was found to be effective for gene transfer. Induction of the virG genes with aceto-syringone did not enhance transformation. Cefotaxime that was supplemented in the plum selection medium to suppress the Agrobacterium vector seriously inhibited leaf disk regeneration. However, in applies it was not detrimental. With further apple transformation experiments, factors such as preculturing, age of leaves, sucrose and cefotaxime concentrations did not increase the transformation efficiency of the marker gene. The harpin protein, essential for the pathogenicity of Pseudomonas syringae pv. syringae which incites bacterial canker of stone fruit, ws amplified and cloned into an expression vector. The fusion protein was purified. This will be used in future studies to elucidate the host-pathogen interaction, and to identify antibacterial genes. (author)

  9. In vivo transformation of neural stem cells following transplantation in the injured nervous system.

    Science.gov (United States)

    Radtke, Christine; Redeker, Joern; Jokuszies, Andreas; Vogt, Peter M

    2010-04-01

    Johnson et al report tumor formation following murine neural precursor cell transplantation in a rat peripheral nerve injury model, emphasizing the importance of full in vitro characterization of cells prior to transplantation. Cell lines can change during expansion and subclones which may become tumerogenic may be selected in the process of expansion. Cell transplantation studies with committed cells that have been minimally manipulated and expanded in culture such as olfactory ensheathing cells and Schwann cells may pose less risk of tumerogenicity, but have the disadvantage of limited cell harvest yields. The balance between in vitro transformation of expanded cell lines and the limitation of cell harvest yields from preparation of more stable committed cells must be considered in selection of cells for therapeutic intervention for nerve repair. Copyright Thieme Medical Publishers.

  10. Sesquiterpene lactones isolated from indigenous Middle Eastern plants inhibit tumor promoter-induced transformation of JB6 cells

    Directory of Open Access Journals (Sweden)

    Saikali Melody

    2012-07-01

    Full Text Available Abstract Background Sesquiterpene lactones (SL are plant secondary metabolites that are known for their anti-fungal, anti-bacterial, anti-inflammatory, and anti-tumor properties. Considering that several SL-derived drugs are currently in cancer clinical trials, we have tested two SL molecules, 3-β-methoxy-iso-seco-tanapartholide (β-tan isolated from Achillea falcata and salograviolide A (Sal A isolated from Centaurea ainetensis, for their anti-tumor properties. We used the mouse epidermal JB6P + cells as a model for tumor promotion and cellular transformation. Key players that are involved in cellular transformation and tumorigenesis are the AP-1 and NF-κB transcription factors; therefore, we assessed how β-tan and Sal A modulate their signaling pathways in JB6P + cells. Methods The effects of β-tan and Sal A on the growth of normal and neoplastic keratinocytes and on the tumor promotion-responsive JB6P + cells were determined using the MTT assay. Anchorage-independent cell growth transformation assays were used to evaluate the anti-tumor promoting properties of these SL molecules in JB6P + cells and dual luciferase reporter assays and western blot analysis were used to investigate their effects on tumor promoter-induced AP-1 and NF-κB activities and protein levels of key AP-1 and NF-кB target genes. Results β-tan and Sal A selectively inhibited tumor promoter-induced cell growth and transformation of JB6P + cells at concentrations that do not affect JB6P + and primary keratinocytes basal cell growth. In addition, both molecules reduced basal and tumor promoter-induced NF-κB transcriptional activities, differentially regulated basal and tumor promoter-induced AP-1 transcriptional activities, and modulated key players of the AP-1 and NF-κB signaling pathways. Conclusions These results highlight the anti-tumor promoting properties of β-tan and Sal A. These SL molecules isolated from two plant species native to

  11. Sesquiterpene lactones isolated from indigenous Middle Eastern plants inhibit tumor promoter-induced transformation of JB6 cells.

    Science.gov (United States)

    Saikali, Melody; Ghantous, Akram; Halawi, Racha; Talhouk, Salma N; Saliba, Najat A; Darwiche, Nadine

    2012-07-09

    Sesquiterpene lactones (SL) are plant secondary metabolites that are known for their anti-fungal, anti-bacterial, anti-inflammatory, and anti-tumor properties. Considering that several SL-derived drugs are currently in cancer clinical trials, we have tested two SL molecules, 3-β-methoxy-iso-seco-tanapartholide (β-tan) isolated from Achillea falcata and salograviolide A (Sal A) isolated from Centaurea ainetensis, for their anti-tumor properties. We used the mouse epidermal JB6P + cells as a model for tumor promotion and cellular transformation. Key players that are involved in cellular transformation and tumorigenesis are the AP-1 and NF-κB transcription factors; therefore, we assessed how β-tan and Sal A modulate their signaling pathways in JB6P + cells. The effects of β-tan and Sal A on the growth of normal and neoplastic keratinocytes and on the tumor promotion-responsive JB6P + cells were determined using the MTT assay. Anchorage-independent cell growth transformation assays were used to evaluate the anti-tumor promoting properties of these SL molecules in JB6P + cells and dual luciferase reporter assays and western blot analysis were used to investigate their effects on tumor promoter-induced AP-1 and NF-κB activities and protein levels of key AP-1 and NF-кB target genes. β-tan and Sal A selectively inhibited tumor promoter-induced cell growth and transformation of JB6P + cells at concentrations that do not affect JB6P + and primary keratinocytes basal cell growth. In addition, both molecules reduced basal and tumor promoter-induced NF-κB transcriptional activities, differentially regulated basal and tumor promoter-induced AP-1 transcriptional activities, and modulated key players of the AP-1 and NF-κB signaling pathways. These results highlight the anti-tumor promoting properties of β-tan and Sal A. These SL molecules isolated from two plant species native to the Middle East may provide opportunities for complementary

  12. Stem cell property of postmigratory cranial neural crest cells and their utility in alveolar bone regeneration and tooth development.

    Science.gov (United States)

    Chung, Il-Hyuk; Yamaza, Takayoshi; Zhao, Hu; Choung, Pill-Hoon; Shi, Songtao; Chai, Yang

    2009-04-01

    The vertebrate neural crest is a multipotent cell population that gives rise to a variety of different cell types. We have discovered that postmigratory cranial neural crest cells (CNCCs) maintain mesenchymal stem cell characteristics and show potential utility for the regeneration of craniofacial structures. We are able to induce the osteogenic differentiation of postmigratory CNCCs, and this differentiation is regulated by bone morphogenetic protein (BMP) and transforming growth factor-beta signaling pathways. After transplantation into a host animal, postmigratory CNCCs form bone matrix. CNCC-formed bones are distinct from bones regenerated by bone marrow mesenchymal stem cells. In addition, CNCCs support tooth germ survival via BMP signaling in our CNCC-tooth germ cotransplantation system. Thus, we conclude that postmigratory CNCCs preserve stem cell features, contribute to craniofacial bone formation, and play a fundamental role in supporting tooth organ development. These findings reveal a novel function for postmigratory CNCCs in organ development, and demonstrate the utility of these CNCCs in regenerating craniofacial structures.

  13. DNA Uptake by Transformable Bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Lacks, Sanford A.

    1999-03-31

    The various processes of DNA uptake by cells can be categorized as: viral DNA entry, conjugation, or transformation. Within each category, a variety of mechanisms have been found. However, considerable similarities occur among the different mechanisms of conjugation and, especially, transformation. All of these natural mechanisms of DNA transfer are quite elaborate and involve multiple protein components, as the case may be, of the virus, the donor cell, and the recipient cell. The mechanisms of viral infection and conjugation will be discussed mainly with respect to their relevance to transformation.

  14. DNA UPTAKE BY TRANSFORMABLE BACTERIA

    Energy Technology Data Exchange (ETDEWEB)

    LACKS,S.A.

    1999-09-07

    The various processes of DNA uptake by cells can be categorized as: viral DNA entry, conjugation, or transformation. Within each category, a variety of mechanisms have been found. However, considerable similarities occur among the different mechanisms of conjugation and, especially, transformation. All of these natural mechanisms of DNA transfer are quite elaborate and involve multiple protein components, as the case may be, of the virus, the donor cell, and the recipient cell. The mechanisms of viral infection and conjugation will be discussed mainly with respect to their relevance to transformation.

  15. Educating for Transforming Our World: Revisiting International Debates Surrounding Education for Sustainable Development

    Science.gov (United States)

    Mochizuki, Yoko

    2016-01-01

    In 2015, the United Nations (UN) General Assembly adopted a resolution titled "Transforming our world: the 2030 Agenda for Sustainable Development" and a set of 17 Sustainable Development Goals (SDGs). The notion of "transformative education" is being mainstreamed in the work of UNESCO within the new framework of the SDGs,…

  16. Proteome-wide analysis of protein abundance and turnover remodelling during oncogenic transformation of human breast epithelial cells [version 1; referees: 2 approved, 1 approved with reservations

    Directory of Open Access Journals (Sweden)

    Tony Ly

    2018-05-01

    Full Text Available Background: Viral oncogenes and mutated proto-oncogenes are potent drivers of cancer malignancy. Downstream of the oncogenic trigger are alterations in protein properties that give rise to cellular transformation and the acquisition of malignant cellular phenotypes. Developments in mass spectrometry enable large-scale, multidimensional characterisation of proteomes. Such techniques could provide an unprecedented, unbiased view of how oncogene activation remodels a human cell proteome. Methods: Using quantitative MS-based proteomics and cellular assays, we analysed how transformation induced by activating v-Src kinase remodels the proteome and cellular phenotypes of breast epithelial (MCF10A cells. SILAC MS was used to comprehensively characterise the MCF10A proteome and to measure v-Src-induced changes in protein abundance across seven time-points (1-72 hrs. We used pulse-SILAC MS (Boisvert et al., 2012, to compare protein synthesis and turnover in control and transformed cells. Follow-on experiments employed a combination of cellular and functional assays to characterise the roles of selected Src-responsive proteins. Results: Src-induced transformation changed the expression and/or turnover levels of ~3% of proteins, affecting ~1.5% of the total protein molecules in the cell. Transformation increased the average rate of proteome turnover and disrupted protein homeostasis. We identify distinct classes of protein kinetics in response to Src activation. We demonstrate that members of the polycomb repressive complex 1 (PRC1 are important regulators of invasion and migration in MCF10A cells. Many Src-regulated proteins are present in low abundance and some are regulated post-transcriptionally. The signature of Src-responsive proteins is highly predictive of poor patient survival across multiple cancer types. Open access to search and interactively explore all these proteomic data is provided via the EPD database (www.peptracker.com/epd. Conclusions

  17. 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

    2012-01-09

    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. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Differential gene expression and clonal selection during cellular transformation induced by adhesion deprivation

    Directory of Open Access Journals (Sweden)

    Kumar Mahesh J

    2010-12-01

    Full Text Available Abstract Background Anchorage independent growth is an important hallmark of oncogenic transformation. Previous studies have shown that when adhesion dependent fibroblasts were prevented from adhering to a substrate they underwent anoikis. In the present study we have demonstrated how anoikis resistant cells gain the transformation related properties with sequential selection of genes. We have proposed this process as a model system for selection of transformed cells from normal cells. Results This report demonstrates that some fibroblasts can survive during late stages of anoikis, at which time they exhibit transformation-associated properties such as in vitro colony formation in soft agar and in vivo subcutaneous tumour formation in nude mice. Cytogenetic characterisation of these cells revealed that they contained a t (2; 2 derivative chromosome and they have a selective survival advantage in non adherent conditions. Gene expression profile indicated that these cells over expressed genes related to hypoxia, glycolysis and tumor suppression/metastasis which could be helpful in their retaining a transformed phenotype. Conclusion Our results reveal some new links between anoikis and cell transformation and they provide a reproducible model system which can potentially be useful to study multistage cancer and to identify new targets for drug development.

  19. MLL-ENL cooperates with SCF to transform primary avian multipotent cells.

    Science.gov (United States)

    Schulte, Cathleen E; von Lindern, Marieke; Steinlein, Peter; Beug, Hartmut; Wiedemann, Leanne M

    2002-08-15

    The MLL gene is targeted by chromosomal translocations, which give rise to heterologous MLL fusion proteins and are associated with distinct types of acute lymphoid and myeloid leukaemia. To determine how MLL fusion proteins alter the proliferation and/or differentiation of primary haematopoietic progenitors, we introduced the MLL-AF9 and MLL-ENL fusion proteins into primary chicken bone marrow cells. Both fusion proteins caused the sustained outgrowth of immature haematopoietic cells, which was strictly dependent on stem cell factor (SCF). The renewing cells have a long in vitro lifespan exceeding the Hayflick limit of avian cells. Analysis of clonal cultures identified the renewing cells as immature, multipotent progenitors, expressing erythroid, myeloid, lymphoid and stem cell surface markers. Employing a two-step commitment/differentiation protocol involving the controlled withdrawal of SCF, the MLL-ENL-transformed progenitors could be induced to terminal erythroid or myeloid differentiation. Finally, in cooperation with the weakly leukaemogenic receptor tyrosine kinase v-Sea, the MLL-ENL fusion protein gave rise to multilineage leukaemia in chicks, suggesting that other activated, receptor tyrosine kinases can substitute for ligand-activated c-Kit in vivo.

  20. 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...... previous results confirms the existence of TGF-alpha, EGF, and EGF-receptors in the majority of oral squamous cell carcinomas and their metastases......., 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...

  1. Clinical-grade production of human mesenchymal stromal cells: occurrence of aneuploidy without transformation.

    Science.gov (United States)

    Tarte, Karin; Gaillard, Julien; Lataillade, Jean-Jacques; Fouillard, Loic; Becker, Martine; Mossafa, Hossein; Tchirkov, Andrei; Rouard, Hélène; Henry, Catherine; Splingard, Marie; Dulong, Joelle; Monnier, Delphine; Gourmelon, Patrick; Gorin, Norbert-Claude; Sensebé, Luc

    2010-02-25

    Clinical-grade human mesenchymal stromal cells (MSCs) have been expanded in vitro for tissue engineering or immunoregulatory purposes without standardized culture conditions or release criteria. Although human MSCs show poor susceptibility for oncogenic transformation, 2 recent studies described their capacity to accumulate chromosomal instability and to give rise to carcinoma in immunocompromised mice after long-term culture. We thus investigated the immunologic and genetic features of MSCs expanded with fetal calf serum and fibroblast growth factor or with platelet lysate in 4 cell-therapy facilities during 2 multicenter clinical trials. Cultured MSCs showed a moderate expression of human leukocyte antigen-DR without alteration of their low immunogenicity or their immunomodulatory capacity. Moreover, some transient and donor-dependent recurring aneuploidy was detected in vitro, independently of the culture process. However, MSCs with or without chromosomal alterations showed progressive growth arrest and entered senescence without evidence of transformation either in vitro or in vivo.

  2. c-Jun/AP-1 pathway-mediated cyclin D1 expression participates in low dose arsenite-induced transformation in mouse epidermal JB6 Cl41 cells

    International Nuclear Information System (INIS)

    Zhang Dongyun; Li Jingxia; Gao Jimin; Huang Chuanshu

    2009-01-01

    Arsenic is a well-documented human carcinogen associated with skin carcinogenesis. Our previous work reveals that arsenite exposure is able to induce cell transformation in mouse epidermal cell JB6 Cl41 through the activation of ERK, rather than JNK pathway. Our current studies further evaluate downstream pathway in low dose arsenite-induced cell transformation in JB6 Cl41 cells. Our results showed that treatment of cells with low dose arsenite induced activation of c-Jun/AP-1 pathway, and ectopic expression of dominant negative mutant of c-Jun (TAM67) blocked arsenite-induced transformation. Furthermore, our data indicated that cyclin D1 was an important downstream molecule involved in c-Jun/AP-1-mediated cell transformation upon low dose arsenite exposure, because inhibition of cyclin D1 expression by its specific siRNA in the JB6 Cl41 cells resulted in impairment of anchorage-independent growth of cells induced by low dose arsenite. Collectively, our results demonstrate that c-Jun/AP-1-mediated cyclin D1 expression is at least one of the key events implicated in cell transformation upon low dose arsenite exposure

  3. Transformation of the genital epithelial tract occurs early in California sea lion development

    Science.gov (United States)

    Barragán-Vargas, Cecilia; Montano-Frías, Jorge; Ávila Rosales, Germán; Godínez-Reyes, Carlos R.; Acevedo-Whitehouse, Karina

    2016-01-01

    An unusually high prevalence of metastatic urogenital carcinoma has been observed in free-ranging California sea lions stranded off the coast of California in the past two decades. No cases have been reported for sea lions in the relatively unpolluted Gulf of California. We investigated occurrence of genital epithelial transformation in 60 sea lions (n=57 pups and 3 adult females) from the Gulf of California and examined whether infection by a viral pathogen previously found to be associated with urogenital carcinoma accounted for such alterations. We also explored the contribution of MHC class II gene expression on transformation. Cellular alterations, such as squamous cell atypia (ASC), atypical squamous cells of undetermined significance (ASCUS) and low-grade squamous intraepithelial lesions were observed in 42% of the pups and in 67% of the adult females. Normal genital epithelium was more common in male than female pups. ASC was five times more likely to occur in older pups. Epithelial alterations were unrelated to infection by the potentially oncogenic otarine type I gammaherpesvirus (OtHV-1), but ASCUS was more common in pups with marked and severe inflammation. Expression of MHC class II DRB loci (Zaca DRB-D) by peripheral antigen-presenting leucocytes showed a slightly ‘protective’ effect for ASC. We propose that transformation of the California sea lion genital epithelium is relatively common in young animals, increases with age and is probably the result of infection by an unidentified pathogen. Expression of a specific MHC class II gene, suggestive of presentation of specific antigenic peptides to immune effectors, appears to lower the risk of transformation. Our study provides the first evidence that epithelial transformation of the California sea lion genital tract is relatively common, even from an early age, and raises questions regarding differences in sea lion cancer-detection and -repair success between geographical regions. PMID:27069641

  4. DEVELOPING MUSLIM COMMUNTIES IN THE PHILIPPINES THROUGH TRANSFORMATIONAL LEADERSHIP: AN ISLAMIC PERSPECTIVE

    Directory of Open Access Journals (Sweden)

    Sapia Moalam Abdulrachman

    2012-08-01

    Full Text Available This research concludes that development of Muslim communities in the Philippines primarily relies on local initiatives and people’s assertive character to institute behavioral reform. It entails a transformation process involving all sectors of the society in such a way that true and committed Muslim leaders will emerge to provide direction and at the same time orchestrate the development of the communities.It is therefore argued that transformational leadership is the most appropriate model that could improve the living conditions of Muslims in the Philippines Firstly, this study provides the empirical evidence that leaders and followers believe that it is through Islamic leadership that their communities can be developed. Secondly, the history of the leadership of Prophet Mohammad and his four caliphs proved that Islamic leadership is indeed transformational leadership one, hence, they deserve to be emulated by Muslims.

  5. A Rapid, Highly Efficient and Economical Method of Agrobacterium-Mediated In planta Transient Transformation in Living Onion Epidermis

    Science.gov (United States)

    Xu, Kedong; Huang, Xiaohui; Wu, Manman; Wang, Yan; Chang, Yunxia; Liu, Kun; Zhang, Ju; Zhang, Yi; Zhang, Fuli; Yi, Liming; Li, Tingting; Wang, Ruiyue; Tan, Guangxuan; Li, Chengwei

    2014-01-01

    Transient transformation is simpler, more efficient and economical in analyzing protein subcellular localization than stable transformation. Fluorescent fusion proteins were often used in transient transformation to follow the in vivo behavior of proteins. Onion epidermis, which has large, living and transparent cells in a monolayer, is suitable to visualize fluorescent fusion proteins. The often used transient transformation methods included particle bombardment, protoplast transfection and Agrobacterium-mediated transformation. Particle bombardment in onion epidermis was successfully established, however, it was expensive, biolistic equipment dependent and with low transformation efficiency. We developed a highly efficient in planta transient transformation method in onion epidermis by using a special agroinfiltration method, which could be fulfilled within 5 days from the pretreatment of onion bulb to the best time-point for analyzing gene expression. The transformation conditions were optimized to achieve 43.87% transformation efficiency in living onion epidermis. The developed method has advantages in cost, time-consuming, equipment dependency and transformation efficiency in contrast with those methods of particle bombardment in onion epidermal cells, protoplast transfection and Agrobacterium-mediated transient transformation in leaf epidermal cells of other plants. It will facilitate the analysis of protein subcellular localization on a large scale. PMID:24416168

  6. A rapid method to screen for cell-wall mutants using discriminant analysis of Fourier transform infrared spectra

    International Nuclear Information System (INIS)

    Chen LiMei; Carpita, N.C.; Reiter, W.D.; Wilson, R.H.; Jeffries, C.; McCann, M.C.

    1998-01-01

    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)

  7. Development of low AC loss windings for superconducting traction transformer

    International Nuclear Information System (INIS)

    Kamijo, H; Hata, H; Fukumoto, Y; Tomioka, A; Bohno, T; Yamada, H; Ayai, N; Yamasaki, K; Kato, T; Iwakuma, M; Funaki, K

    2010-01-01

    We have been developing a light weight and high efficiency superconducting traction transformer for railway rolling stock. We designed and fabricated a prototype superconducting traction transformer of a floor-mount type for Shinkansen rolling stock in 2004. We performed the type-test, the system-test, and the vibration-test. Consequently, we could verify that the transformer satisfied the requirement almost exactly as initially planned. However, there have been raised some problems to be solved to put superconducting traction transformer into practical use such that AC loss of the superconducting tape must be lower and the capacity of the refrigerator must be larger. Especially it is the most important to reduce the AC loss of superconducting windings for lightweight and high efficiency. The AC loss must be reduced near the theoretical value of superconducting tape with multifilament. In this study, we fabricated and evaluated the Bi2223 tapes as introduced various measures to reduce the AC loss. We confirmed that the AC loss of the narrow type of Bi2223 tapes with twist of filaments is lower, and we fabricated windings of this tape for use in superconducting traction transformer.

  8. An efficient protocol for the Agrobacterium-mediated genetic transformation of microalga Chlamydomonas reinhardtii.

    Science.gov (United States)

    Pratheesh, P T; Vineetha, M; Kurup, G Muraleedhara

    2014-06-01

    Algal-based recombinant protein production has gained immense interest in recent years. The development of algal expression system was earlier hindered due to the lack of efficient and cost-effective transformation techniques capable of heterologous gene integration and expression. The recent development of Agrobacterium-mediated genetic transformation method is expected to be the ideal solution for these problems. We have developed an efficient protocol for the Agrobacterium-mediated genetic transformation of microalga Chlamydomonas reinhardtii. Pre-treatment of Agrobacterium in TAP induction medium (pH 5.2) containing 100 μM acetosyringone and 1 mM glycine betaine and infection of Chlamydomonas with the induced Agrobacterium greatly improved transformation frequency. This protocol was found to double the number of transgenic events on selection media compared to that of previous reports. PCR was used successfully to amplify fragments of the hpt and GUS genes from transformed cells, while Southern blot confirmed the integration of GUS gene into the genome of C. reinhardtii. RT-PCR, Northern blot and GUS histochemical analyses confirm GUS gene expression in the transgenic cell lines of Chlamydomonas. This protocol provides a quick, efficient, economical and high-frequency transformation method for microalgae.

  9. Transformational Technologies to Expedite Space Access and Development

    International Nuclear Information System (INIS)

    Rather, John D. G.

    2010-01-01

    Throughout history the emergence of new technologies has enabled unforeseen breakthrough capabilities that rapidly transformed the world. Some global examples from the twentieth century include AC electric power, nuclear energy, and turbojet engines. At the systems level, success of both Apollo and the Space Shuttle programs depended upon taming hydrogen propulsion and developing high-temperature atmospheric reentry materials. Human space development now is stymied because of a great need for breakthrough technologies and strategies. It is believed that new capabilities exist within the present states-of-the-art of superconducting technology that can be implemented to transform the future of human space development. This paper is an overview of three other papers presented within this forum, which summarizes the principles and consequences of StarTram, showing how the resulting breakthrough advantages can lead directly to safe space tourism and massive development of the moon, Mars and the outer solar system. StarTram can implement cost-effective solar power from space, simple utilization of asteroid material to protect humans from ionizing radiation, and effective defense of the Earth from devastating cosmic impacts. Synergistically, StarTram technologies will revolutionize ground transportation on the Earth, leading to enormous reduction in energy consumption and creation of millions of jobs. High energy lasers will also be discussed because of their importance to power beaming applications.

  10. Cadmium-109 uptake by tumors derived from Balb C/3T3 cell lines with varying degrees of the transformed phenotype

    International Nuclear Information System (INIS)

    Morton, K.; Alazraki, N.; Winge, D.; Lynch, R.E.

    1986-01-01

    To determine if tumors are rich in metallothionein, the authors measured the vivo uptake of subcutaneously-injected carrier-free cadmium-109 in tumors and in normal tissues of Balb/C mice. The tumors were grown in the mice from cultured Balb/3T3 cells transformed by the Moloney murine sarcoma virus. Uptake of cadmium-109 per gram of tissue was greatest for liver, kidney, and spleen. However, tumor uptake of cadmium-109 was markedly greater than that in blood, skeletal muscle, bones, intestine or adipose tissue. B Sephadex G-75 chromatography, the radioactivity in tumor and in liver lysates eluted with cytochrome-C, a molecule similar in molecular weight to metal-lothionein. To determine if metallothionein levels are related to the degree of malignancy of tumors, cadmium-109 uptake in the tumors from the virally-transformed cells was compared to that in tumors from non-transformed Balb/3T3 cells and two derivative chemically transformed cell lines. There was strong correlation between the substrate-independent growth in soft agarose of the four cell lines, the rate of growth of the corresponding tumors, and the amount of cadmium-109 uptake in the tumors. The authors conclude that metallothionein levels may be elevated in tumors as a function of the degree of expression of the transformed phenotype

  11. Dose fractionation effects in plateau-phase cultures of C3H 10T1/2 cells and their transformed counterparts

    International Nuclear Information System (INIS)

    Zeman, E.M.; Bedford, J.S.

    1985-01-01

    A comparison of γ-ray dose fractionation effects was made using plateau-phase cultures of C3H 10T1/2 cells and their transformed counterparts in an attempt to simulate basically similar populations of cells that differ primarily in their turnover rates. The status of cell populations with respect to their turnover rates may be an important factor influencing dose fractionation effects in early- and late-responding tissues. In this cell culture system, the rate of cell turnover was approximately three times higher for the plateau-phase transformed cultures. While the single acute dose survival curves for log-phase cells were indistinguishable, there were significant differences between the survival curves for plateau-phase cultures of the two cell types. Both cell lines had a similar capacity for repair of sublethal damage, but untransformed cells had a much greater capacity to repair potentially lethal damage in plateau phase. Multifraction survival curves were determined for both cell lines for doses per fraction ranging from 9.0 to 0.8 Gy, and from these isoeffect curves of log total dose versus dose per fraction were derived. The isoeffect curve for the slowly cycling, untransformed cells was found to be appreciably steeper than that for the more rapidly cycling transformed cells, a finding consistent with previously reported differences in dose fractionation isoeffect curves for early- and late-responding tissues in vivo

  12. The genome of herpesvirus saimiri C488 which is capable of transforming human T cells

    International Nuclear Information System (INIS)

    Ensser, Armin; Thurau, Mathias; Wittmann, Sabine; Fickenscher, Helmut

    2003-01-01

    Herpesvirus saimiri (HVS), the rhadinovirus prototype, is apathogenic in the persistently infected natural host, the squirrel monkey, but causes acute T cell leukemia in other New World primate species. In contrast to subgroups A and B, only strains of HVS subgroup C such as C488 are capable of transforming primary human T cells to stable antigen-independent growth in culture. Here, we report the complete 155-kb genome sequence of the transformation-competent HVS strain C488. The A+T-rich unique L-DNA of 113,027 bp encodes at least 77 open reading frames and 5 URNAs. In addition to the viral oncogenes stp and tip, only a few genes including the transactivator orf50 and the glycoprotein orf51 are highly divergent. In a series of new primary HVS isolates, the subgroup-specific divergence of the orf50/orf51 alleles was studied. In these new isolates, the orf50/orf51 alleles of the respective subgroup segregate with the stp and/or tip oncogene alleles, which are essential for transformation

  13. 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...

  14. The contribution of heavy metals in cigarette smoke condensate to malignant transformation of breast epithelial cells and in vivo initiation of neoplasia through induction of a PI3K–AKT–NFκB cascade

    Energy Technology Data Exchange (ETDEWEB)

    Mohapatra, Purusottam; Preet, Ranjan; Das, Dipon; Satapathy, Shakti Ranjan [Cancer Biology Division, KIIT School of Biotechnology, KIIT University, Campus-11, Patia, Bhubaneswar, Orissa 751024 (India); Siddharth, Sumit [Cancer Biology Division, KIIT School of Biotechnology, KIIT University, Campus-11, Patia, Bhubaneswar, Orissa 751024 (India); Department of Infection Biology, Institute of Life Science, Nalco Square, Bhubaneswar, Orissa 751021 (India); Choudhuri, Tathagata [Department of Infection Biology, Institute of Life Science, Nalco Square, Bhubaneswar, Orissa 751021 (India); Wyatt, Michael D. [Department of Drug Discovery and Biomedical Sciences, South Carolina College of Pharmacy, University of South Carolina, Columbia, SC (United States); Kundu, Chanakya Nath, E-mail: cnkundu@gmail.com [Cancer Biology Division, KIIT School of Biotechnology, KIIT University, Campus-11, Patia, Bhubaneswar, Orissa 751024 (India)

    2014-01-01

    Cigarette smoking is a crucial factor in the development and progression of multiple cancers including breast. Here, we report that repeated exposure to a fixed, low dose of cigarette smoke condensate (CSC) prepared from Indian cigarettes is capable of transforming normal breast epithelial cells, MCF-10A, and delineate the biochemical basis for cellular transformation. CSC transformed cells (MCF-10A-Tr) were capable of anchorage-independent growth, and their anchorage dependent growth and colony forming ability were higher compared to the non-transformed MCF-10A cells. Increased expression of biomarkers representative of oncogenic transformation (NRP-1, Nectin-4), and anti-apoptotic markers (PI3K, AKT, NFκB) were also noted in the MCF-10A-Tr cells. Short tandem repeat (STR) profiling of MCF-10A and MCF-10A-Tr cells revealed that transformed cells acquired allelic variation during transformation, and had become genetically distinct. MCF-10A-Tr cells formed solid tumors when implanted into the mammary fat pads of Balb/c mice. Data revealed that CSC contained approximately 1.011 μg Cd per cigarette equivalent, and Cd (0.0003 μg Cd/1 × 10{sup 7} cells) was also detected in the lysates from MCF-10A cells treated with 25 μg/mL CSC. In similar manner to CSC, CdCl{sub 2} treatment in MCF-10A cells caused anchorage independent colony growth, higher expression of oncogenic proteins and increased PI3K–AKT–NFκB protein expression. An increase in the expression of PI3K–AKT–NFκB was also noted in the mice xenografts. Interestingly, it was noted that CSC and CdCl{sub 2} treatment in MCF-10A cells increased ROS. Collectively, results suggest that heavy metals present in cigarettes of Indian origin may substantially contribute to tumorigenesis by inducing intercellular ROS accumulation and increased expression of PI3K, AKT and NFκB proteins. - Highlights: • Repeated exposure of CSC causes malignant transformation in MCF-10A. • MCF-10A-Tr cells showed a distinct

  15. The contribution of heavy metals in cigarette smoke condensate to malignant transformation of breast epithelial cells and in vivo initiation of neoplasia through induction of a PI3K–AKT–NFκB cascade

    International Nuclear Information System (INIS)

    Mohapatra, Purusottam; Preet, Ranjan; Das, Dipon; Satapathy, Shakti Ranjan; Siddharth, Sumit; Choudhuri, Tathagata; Wyatt, Michael D.; Kundu, Chanakya Nath

    2014-01-01

    Cigarette smoking is a crucial factor in the development and progression of multiple cancers including breast. Here, we report that repeated exposure to a fixed, low dose of cigarette smoke condensate (CSC) prepared from Indian cigarettes is capable of transforming normal breast epithelial cells, MCF-10A, and delineate the biochemical basis for cellular transformation. CSC transformed cells (MCF-10A-Tr) were capable of anchorage-independent growth, and their anchorage dependent growth and colony forming ability were higher compared to the non-transformed MCF-10A cells. Increased expression of biomarkers representative of oncogenic transformation (NRP-1, Nectin-4), and anti-apoptotic markers (PI3K, AKT, NFκB) were also noted in the MCF-10A-Tr cells. Short tandem repeat (STR) profiling of MCF-10A and MCF-10A-Tr cells revealed that transformed cells acquired allelic variation during transformation, and had become genetically distinct. MCF-10A-Tr cells formed solid tumors when implanted into the mammary fat pads of Balb/c mice. Data revealed that CSC contained approximately 1.011 μg Cd per cigarette equivalent, and Cd (0.0003 μg Cd/1 × 10 7 cells) was also detected in the lysates from MCF-10A cells treated with 25 μg/mL CSC. In similar manner to CSC, CdCl 2 treatment in MCF-10A cells caused anchorage independent colony growth, higher expression of oncogenic proteins and increased PI3K–AKT–NFκB protein expression. An increase in the expression of PI3K–AKT–NFκB was also noted in the mice xenografts. Interestingly, it was noted that CSC and CdCl 2 treatment in MCF-10A cells increased ROS. Collectively, results suggest that heavy metals present in cigarettes of Indian origin may substantially contribute to tumorigenesis by inducing intercellular ROS accumulation and increased expression of PI3K, AKT and NFκB proteins. - Highlights: • Repeated exposure of CSC causes malignant transformation in MCF-10A. • MCF-10A-Tr cells showed a distinct STR profile and

  16. Exome sequencing of bilateral testicular germ cell tumors suggests independent development lineages.

    Science.gov (United States)

    Brabrand, Sigmund; Johannessen, Bjarne; Axcrona, Ulrika; Kraggerud, Sigrid M; Berg, Kaja G; Bakken, Anne C; Bruun, Jarle; Fosså, Sophie D; Lothe, Ragnhild A; Lehne, Gustav; Skotheim, Rolf I

    2015-02-01

    Intratubular germ cell neoplasia, the precursor of testicular germ cell tumors (TGCTs), is hypothesized to arise during embryogenesis from developmentally arrested primordial germ cells (PGCs) or gonocytes. In early embryonal life, the PGCs migrate from the yolk sac to the dorsal body wall where the cell population separates before colonizing the genital ridges. However, whether the malignant transformation takes place before or after this separation is controversial. We have explored the somatic exome-wide mutational spectra of bilateral TGCT to provide novel insight into the in utero critical time frame of malignant transformation and TGCT pathogenesis. Exome sequencing was performed in five patients with bilateral TGCT (eight tumors), of these three patients in whom both tumors were available (six tumors) and two patients each with only one available tumor (two tumors). Selected loci were explored by Sanger sequencing in 71 patients with bilateral TGCT. From the exome-wide mutational spectra, no identical mutations in any of the three bilateral tumor pairs were identified. Exome sequencing of all eight tumors revealed 87 somatic non-synonymous mutations (median 10 per tumor; range 5-21), some in already known cancer genes such as CIITA, NEB, platelet-derived growth factor receptor α (PDGFRA), and WHSC1. SUPT6H was found recurrently mutated in two tumors. We suggest independent development lineages of bilateral TGCT. Thus, malignant transformation into intratubular germ cell neoplasia is likely to occur after the migration of PGCs. We reveal possible drivers of TGCT pathogenesis, such as mutated PDGFRA, potentially with therapeutic implications for TGCT patients. Copyright © 2014 Neoplasia Press, Inc. Published by Elsevier Inc. All rights reserved.

  17. Different roles of ROS and Nrf2 in Cr(VI)-induced inflammatory responses in normal and Cr(VI)-transformed cells

    Energy Technology Data Exchange (ETDEWEB)

    Roy, Ram Vinod; Pratheeshkumar, Poyil; Son, Yong-Ok; Wang, Lei [Center for Research on Environmental Disease, University of Kentucky, 1095 VA Drive, Lexington, KY 40536 (United States); Department of Toxicology and Cancer Biology, College of Medicine, University of Kentucky, 1095 VA Drive, Lexington, KY 40536 (United States); Hitron, John Andrew [Center for Research on Environmental Disease, University of Kentucky, 1095 VA Drive, Lexington, KY 40536 (United States); Divya, Sasidharan Padmaja; Zhang, Zhuo [Department of Toxicology and Cancer Biology, College of Medicine, University of Kentucky, 1095 VA Drive, Lexington, KY 40536 (United States); 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)

    2016-09-15

    Hexavalent chromium (Cr(VI)) is classified as a human carcinogen. Cr(VI) has been associated with adenocarcinomas and squamous cell carcinoma of the lung. The present study shows that acute Cr(VI) treatment in human bronchial epithelial cells (BEAS-2B) increased inflammatory responses (TNF-α, COX-2, and NF-кB/p65) and expression of Nrf2. Cr(VI)-induced generation of reactive oxygen species (ROS) are responsible for increased inflammation. Despite the fact that Nrf2 is a master regulator of response to oxidative stress, silencing of Nrf2 in the acute Cr(VI) treatment had no effect on Cr(VI)-induced inflammation. In contrast, in Cr(VI)-transformed (CrT) cells, Nrf2 is constitutively activated. Knock-down of this protein resulted in decreased inflammation, while silencing of SOD2 and CAT had no effect in the expression of these inflammatory proteins. Results obtained from the knock-down of Nrf2 in CrT cells are very different from the results obtained in the acute Cr(VI) treatment. In BEAS-2B cells, knock-down of Nrf2 had no effect in the inflammation levels, while in CrT cells a decrease in the expression of inflammation markers was observed. These results indicate that before transformation, ROS plays a critical role while Nrf2 not in Cr(VI)-induced inflammation, whereas after transformation (CrT cells), Nrf2 is constitutively activated and this protein maintains inflammation while ROS not. Constitutively high levels of Nrf2 in CrT binds to the promoter regions of COX-2 and TNF-α, leading to increased inflammation. Collectively, our results demonstrate that before cell transformation ROS are important in Cr(VI)-induced inflammation and after transformation a constitutively high level of Nrf2 is important. - Highlights: • Cr(VI)-induced ROS increased inflammation, while Nrf2 had no effect. • In the CrT cells knock-down of Nrf2 resulted in decreased inflammation. • Mechanistic differences in regulating Cr(VI)-induced inflammation.

  18. Advancing Crop Transformation in the Era of Genome Editing[OPEN

    Science.gov (United States)

    Blechl, Ann E.; Brutnell, Thomas P.; Conrad, Liza J.; Gelvin, Stanton B.; Jackson, David P.; Kausch, Albert P.; Lemaux, Peggy G.; Medford, June I.; Orozco-Cárdenas, Martha L.; Tricoli, David M.; Van Eck, Joyce; Voytas, Daniel F.

    2016-01-01

    Plant transformation has enabled fundamental insights into plant biology and revolutionized commercial agriculture. Unfortunately, for most crops, transformation and regeneration remain arduous even after more than 30 years of technological advances. Genome editing provides novel opportunities to enhance crop productivity but relies on genetic transformation and plant regeneration, which are bottlenecks in the process. Here, we review the state of plant transformation and point to innovations needed to enable genome editing in crops. Plant tissue culture methods need optimization and simplification for efficiency and minimization of time in culture. Currently, specialized facilities exist for crop transformation. Single-cell and robotic techniques should be developed for high-throughput genomic screens. Plant genes involved in developmental reprogramming, wound response, and/or homologous recombination should be used to boost the recovery of transformed plants. Engineering universal Agrobacterium tumefaciens strains and recruiting other microbes, such as Ensifer or Rhizobium, could facilitate delivery of DNA and proteins into plant cells. Synthetic biology should be employed for de novo design of transformation systems. Genome editing is a potential game-changer in crop genetics when plant transformation systems are optimized. PMID:27335450

  19. DNA crosslinking and cytotoxicity in normal and transformed human cells treated with antitumor nitrosoureas.

    Science.gov (United States)

    Erickson, L C; Bradley, M O; Ducore, J M; Ewig, R A; Kohn, K W

    1980-01-01

    Normal (IMR-90) and simian virus 40-transformed (VA-13) human embryo cells were treated with antitumor nitrosoureas, and the effects on cell viability and cell DNA were compared. All six nitrosoureas tested were more toxic to VA-13 cells than to IMR-90 cells as measured by decrease in cell proliferation or in colony formation. The nitrosoureas capable of generating alkylisocyanates produced a smaller difference between the cell types than did derivatives lacking this capacity. DNA damage was measured by alkaline elution in cells treated with four chloroethylnitrosoureas. Whereas VA-13 cells exhibited dose-dependent interstrand crosslinking, little or none was detected in IMR-90 cells. The IMR-90 cells, however, exhibited at least as much DNA-protein crosslinking as did VA-13 cells. The results can be interpreted in terms of a possible difference in DNA repair between the cell lines. PMID:6928639

  20. 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.

  1. Cellular and molecular mechanisms in malignant transformation of diploid rodent and human cells by radiation

    International Nuclear Information System (INIS)

    Borek, C.

    1985-01-01

    The development of cell culture systems has made it possible to probe into the effects of radiation at a cellular and molecular level, under defined conditions where homeostatic mechanisms do not prevail. Using in vitro systems free of host-medicated influences, one can assess qualitatively and quantitatively dose-related and time-dependent interactions of radiation with single cells and to evaluate the influences of agents that may enhance or inhibit the oncogenic potential of radiation. These systems are useful in pragmatic studies where dose response relationships and cancer risk estimates are assessed with particular focus on the low dose range of radiation where epidemiological and animal studies are limiting. The in vitro systems serve well also in mechanistic studies where cellular and molecular processes underlying transformation can be elucidated and where the role of modulating factors which determine the frequency and quality of these events can be investigated

  2. Cotton transformation via pollen tube pathway.

    Science.gov (United States)

    Wang, Min; Zhang, Baohong; Wang, Qinglian

    2013-01-01

    Although many gene transfer methods have been employed for successfully obtaining transgenic cotton, the major constraint in cotton improvement is the limitation of genotype because the majority of transgenic methods require plant regeneration from a single transformed cell which is limited by cotton tissue culture. Comparing with other plant species, it is difficult to induce plant regeneration from cotton; currently, only a limited number of cotton cultivars can be cultured for obtaining regenerated plants. Thus, development of a simple and genotype-independent genetic transformation method is particularly important for cotton community. In this chapter, we present a simple, cost-efficient, and genotype-independent cotton transformation method-pollen tube pathway-mediated transformation. This method uses pollen tube pathway to deliver transgene into cotton embryo sacs and then insert foreign genes into cotton genome. There are three major steps for pollen tube pathway-mediated genetic transformation, which include injection of -foreign genes into pollen tube, integration of foreign genes into plant genome, and selection of transgenic plants.

  3. The studies of DNA double-strand break (DSB) rejoining and mRNA expression of repair gene XRCCs in malignant transformed cell lines of human bronchial epithelial cells generated by α-particles

    International Nuclear Information System (INIS)

    Sun Jingfen; Sui Jianli; Geng Yu; Zhou Pingkun; Wu Dechang

    2002-01-01

    Objective: To investigate the efficiency of γ-ray-induced DNA DSB rejoining and the mRNA expression of DNA repair genes in malignantly transformed cell lines of human bronchial epithelial cells generated by exposure to a-particles. Methods: Pulsed field gel electrophoresis (PFGE) was used to detect DNA. DSBs mRNA expression was analyzed by RT-PCR. Results: The residual DNA DSB damage level after 4hrs repair following 0-150 Gy of γ-irradiation in the malignantly transformed cell lines BERP35T-1 and BERP35T-4 was significantly higher than that in their parental BEP2D cells. The analysis of mRNA level revealed a 2.5-to 6.5-fold down-regulated expression of the DNA repair genes XRCC-2, XRCC-3 and Ku80 (XRCC-5) in BERP35T-1 and BERP35T-4 cells as compared with the parental BEP2D cells. In contrast, the expression of DNA-PKcs(XRCC7) was 2.4-fold up-regulated in the transformed cell line BERP35T-4, in which there was a significantly higher proportion of polyploid cells. Conclusion: This study results show that the deficiency of DNA DSB rejoining and depressed mRNA expression of DNA repair genes could be involved in the malignant transformation process of BEP2D cells induced by exposure to α-particles

  4. 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

  5. Quantifying and resolving multiple vector transformants in S. cerevisiae plasmid libraries.

    Science.gov (United States)

    Scanlon, Thomas C; Gray, Elizabeth C; Griswold, Karl E

    2009-11-20

    transformed yeast cells have important implications for yeast library screens. The quantitative information described herein should increase awareness of this issue, and the rapid sequencing approach developed for these studies should be widely useful for identifying multiple vector transformants and avoiding complications associated with cells that have acquired more than one unique plasmid.

  6. Quantifying and resolving multiple vector transformants in S. cerevisiae plasmid libraries

    Directory of Open Access Journals (Sweden)

    Gray Elizabeth C

    2009-11-01

    previously unrecognized prevalence and persistence of multiply transformed yeast cells have important implications for yeast library screens. The quantitative information described herein should increase awareness of this issue, and the rapid sequencing approach developed for these studies should be widely useful for identifying multiple vector transformants and avoiding complications associated with cells that have acquired more than one unique plasmid.

  7. 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.

  8. 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.

  9. Long-term low-dose α-particle enhanced the potential of malignant transformation in human bronchial epithelial cells through MAPK/Akt pathway

    International Nuclear Information System (INIS)

    Liu, Weili; Xiao, Linlin; Dong, Chen; He, Mingyuan; Pan, Yan; Xie, Yuexia; Tu, Wenzhi; Fu, Jiamei; Shao, Chunlin

    2014-01-01

    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

  10. Genetic transformation of intact Lactococcus lactis subsp. lactis by high-voltage electroporation

    Energy Technology Data Exchange (ETDEWEB)

    McIntyre, D.A.; Harlander, S.K. (Univ. of Minnesota, St. Paul (USA))

    1989-03-01

    The objective of this study was to develop a system for electroporating intact cells of Lactococcus lactis subsp. lactis LM0230 (previously designated Streptococcus lactis LM0230) with a commercially available electroporation unit. Parameters which influenced the efficiency of transformation included growth phase and final concentration of cells, ionic strength of the suspending medium, concentration of plasmid DNA, and the amplitude and duration of the pulse. Washed suspensions of intact cells suspended in deionized distilled water were subjected to one high-voltage electric pulse varying in voltage (300 to 900 V corresponding to field strengths of 5 to 17 kV/cm) and duration (100 {mu}s to 1 s). Transformation efficiencies of 10{sup 3} transformants per {mu}g of DNA were obtained when dense suspensions (final concentration, 5 {times} 10{sup 10} CFU/ml) of stationary-phase cells were subjected to one pulse with a peak voltage of 900 V (field strength, 17 kV/cm) and a pulse duration of 5 ms in the presence of plasmid DNA. Dilution of porated cells in broth medium followed by an expression period of 2 h at 30{degree}C was beneficial in enhancing transformation efficiencies. Plasmids ranging in size from 9.8 to 30.0 kilobase pairs could be transformed by this procedure.

  11. Development of a Candida glabrata dominant nutritional transformation marker utilizing the Aspergillus nidulans acetamidase gene (amdS).

    Science.gov (United States)

    Fu, Jianmin; Blaylock, Morganne; Wickes, Cameron F; Welte, William; Mehrtash, Adrian; Wiederhold, Nathan; Wickes, Brian L

    2016-05-01

    The gene encoding Aspergillus nidulans acetamidase (amdS) was placed under control of Candida albicans ACT1 promoter and terminator sequences and then cloned into a plasmid containing C. glabrata ARS10,CEN8 or ARS10+CEN8 sequences. All plasmids transformed C. glabrata wild-type cells to acetamide+, with the ARS-only containing plasmid transforming cells at the highest frequencies (>1.0 × 10(4) transformants μg(-1)). Plasmids were rapidly lost under non-selective conditions with the frequency dependent on chromosomal element, thus recycling the acetamide- phenotype. The amdS plasmid was used to transform a set of clinical isolates resistant to a variety of antifungal drugs. All strains were successfully transformed to the acetamide+ phenotype at high frequency, confirming that this plasmid construct could be used as a simple dominant marker on virtually any strain. Gap repair experiments demonstrated that just as in Saccharomyces cerevisiae, gap repair functions efficiently inC. glabrata, suggesting that C. glabrata has numerous similarities toS. cerevisiae with regard to ease of molecular manipulation. The amdS system is inexpensive and efficient, and combined with existing C. glabrata plasmid elements, confers a high transformation frequency for C. glabrata with a phenotype that can be easily recycled. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  12. P01.29 Mutant (R132H) IDH1-driven cellular transformation makes cells dependent on continued wild type IDH1 expression in a model of in vitro gliomagenesis

    Science.gov (United States)

    Johannessen, T.; Mukherjee, J.; Wood, M.; Viswanath, P.; Ohba, S.; Ronen, S.; Berkvig, R.; Pieper, R.

    2017-01-01

    of the mutant IDH-transformed cells was significantly reduced. This growth suppression was also accompanied by a four-fold increase in annexin V-positive apoptotic cells. Furthermore, the growth suppression in the cells transformed by mutant IDH1 expression could not be reversed by addition of a cell-permeable form of 2-HG. Conclusions: These results show that the in vitro transformative events driven by expression of mutant IDH1 make cells dependent not on continued mutant IDH1 expression, but rather on continued WT IDH1 expression. The data also support the development and testing of agents that can inhibit both the WT and mutant forms of IDH1.

  13. Neoplastic transformation induced by carbon ions.

    Science.gov (United States)

    Bettega, Daniela; Calzolari, Paola; Hessel, Petra; Stucchi, Claudio G; Weyrather, Wilma K

    2009-03-01

    The objective of this experiment was to compare the oncogenic potential of carbon ion beams and conventional photon beams for use in radiotherapy. The HeLa X human skin fibroblast cell line CGL1 was irradiated with carbon ions of three different energies (270, 100, and 11.4 MeV/u). Inactivation and transformation data were compared with those for 15 MeV photons. Inactivation and transformation frequencies for the 270 MeV/u carbon ions were similar to those for 15-MeV photons. The maximal relative biologic effectiveness (RBE(alpha)) values for 100MeV/u and 11.4 MeV/u carbon ions, respectively, were as follows: inactivation, 1.6 +/- 0.2 and 6.7 +/- 0.7; and transformation per surviving cell, 2.5 +/- 0.6 and 12 +/- 3. The curve for dose-transformation per cell at risk exhibited a maximum that was shifted toward lower doses at lower energies. Transformation induction per cell at risk for carbon ions in the entrance channel was comparable to that for photons, whereas for the lower energies, 100 MeV/u and 11 MeV/u, which are representative of the energies delivered to the tumor margins and volume, respectively, the probability of transformation in a single cell was greater than it was for photons. In addition, at isoeffective doses with respect to cell killing, the 11.4-MeV/u beam was more oncogenic than were photons.

  14. Down-regulation of a calmodulin-related gene during transformation of human mammary epithelial cells

    International Nuclear Information System (INIS)

    Yaswen, P.; Smoll, A.; Stampfer, M.R.; Peehl, D.M.; Trask, D.K.; Sager, R.

    1990-01-01

    A human cDNA library obtained from cultured normal mammary epithelial cells (HMECs) was searched by subtractive hybridization for genes whose decrease in expression might be relevant to epithelial transformation. One clone identified by this procedure corresponded to a 1.4 kilobase mRNA, designated NB-1, whose expression was decreased >50-fold in HMECs tumorigenically transformed in vitro after exposure to benzo[α]pyrene and Kirsten sarcoma virus. Sequence analysis of NB-1 cDNA revealed an open reading frame with a high degree of homology to calmodulin. NB-1 expression could be demonstrated by polymerase chain reaction amplification in normal breast, prostate, cervix, and epidermal tissues. The presence of NB-1 transcripts was variable in primary breast carcinoma tissues and undetectable in tumor-derived cell lines of breast, prostate, or other origins. NB-1 mRNA expression could be down-regulated in cultured HMECs by exposure to reconstituted extracellular matrix material, while exposure to transforming growth factor type β increased its relative abundance. The protein encoded by NB-1 may have Ca 2 plus binding properties and perform functions similar to those of authentic calmodulin. Its possible roles in differentiation and/or suppression of tumorigenicity in epithelial tissues remain to be examined

  15. N-methyl-N-nitro-N-nitrosoguanidine-mediated ING4 downregulation contributed to the angiogenesis of transformed human gastric epithelial cells.

    Science.gov (United States)

    Chen, Yansu; Fu, Rui; Xu, Mengdie; Huang, Yefei; Sun, Guixiang; Xu, Lichun

    2018-04-15

    Angiogenesis is associated with the progression and mortality of gastric cancer. Epidemiological evidences indicate that long-term N-nitroso compounds (NOCs) exposure predominantly contributes to the mortality of gastric cancer. Therefore, further reduced mortality of gastric cancer demands to explore the exact mechanisms of NOCs induced angiogenesis. As a tumor suppressor gene, inhibitor of growth protein 4 (ING4) plays an important role in pathological angiogenesis. In this study, we will investigate ING4 expression level in human gastric epithelial cells after the long-term low dose exposure of N-methyl-N-nitro-N-nitrosoguanidine (MNNG) and the pathological impact of MNNG-reduced ING4 on angiogenesis of transformed cells. The soft agar colony formation assay, Western blotting, immunofluorescence and wound healing assay were used to evaluate the characteristics of transformed cells. HUVEC growth and tube formation assays were performed to test the angiogenic abilities. EMSA, luciferase reporter gene assay, real-time PCR and Western blotting were used to explore the exact mechanism. By establishing transformed human gastric epithelial cells via chronic low dose treatment, a gradually ING4 downregulation was observed in the later-stage of MNNG-induced cell transformation. Moreover, we demonstrated that MNNG exposure-reduced ING4 expression significantly resulted into aggravating angiogenesis through increasing the phosphorylation level of NF-κB p65 and subsequently DAN binding activity and regulating the expressions of NF-κB p65 downstream pro-angiogenic genes, MMP-2 and MMP-9. Our findings provided a significant mechanistic insight into angiogenesis of MNNG-transformed human gastric epithelial cell and supported the concept that ING4 may be a relevant therapeutic target for gastric cancer. Copyright © 2018 Elsevier Inc. All rights reserved.

  16. Kidney stem cells in development, regeneration and cancer.

    Science.gov (United States)

    Dziedzic, Klaudyna; Pleniceanu, Oren; Dekel, Benjamin

    2014-12-01

    The generation of nephrons during development depends on differentiation via a mesenchymal to epithelial transition (MET) of self-renewing, tissue-specific stem cells confined to a specific anatomic niche of the nephrogenic cortex. These cells may transform to generate oncogenic stem cells and drive pediatric renal cancer. Once nephron epithelia are formed the view of post-MET tissue renal growth and maintenance by adult tissue-specific epithelial stem cells becomes controversial. Recently, genetic lineage tracing that followed clonal evolution of single kidney cells showed that the need for new cells is constantly driven by fate-restricted unipotent clonal expansions in varying kidney segments arguing against a multipotent adult stem cell model. Lineage-restriction was similarly maintained in kidney organoids grown in culture. Importantly, kidney cells in which Wnt was activated were traced to give significant clonal progeny indicating a clonogenic hierarchy. In vivo nephron epithelia may be endowed with the capacity akin to that of unipotent epithelial stem/progenitor such that under specific stimuli can clonally expand/self renew by local proliferation of mature differentiated cells. Finding ways to ex vivo preserve and expand the observed in vivo kidney-forming capacity inherent to both the fetal and adult kidneys is crucial for taking renal regenerative medicine forward. Some of the strategies used to achieve this are sorting human fetal nephron stem/progenitor cells, growing adult nephrospheres or reprogramming differentiated kidney cells toward expandable renal progenitors. Copyright © 2014. Published by Elsevier Ltd.

  17. Pre-crisis mouse cells show strain-specific covariation in the amount of 54-kilodalton phosphoprotein and in susceptibility to transformation by simian virus 40.

    Science.gov (United States)

    Chen, S; Blanck, G; Pollack, R E

    1983-09-01

    We have used several inbred mouse strains to examine the role of the 54-kilodalton (kDa) cellular phosphoprotein in transformation by the papovavirus simian virus 40. We have measured the endogenous 54-kDa phosphoprotein in cells obtained from these inbred mouse strains. To study the effect of passage, cell cultures were measured for amount of the 54-kDa phosphoprotein at the 2nd and 12th passages. In the absence of any transforming agent, the amount of endogenous 54-kDa phosphoprotein in early pre-crisis mouse cells varied in a strain-specific way. Transformation frequency varied coordinately with endogenous 54-kDa expression. Mouse strains whose cells produced a high level of endogenous 54-kDa phosphoprotein on passage did not further increase its expression after simian virus 40 transformation.

  18. Inhibition of radiation-induced transformation in vitro by bacterial endotoxins

    International Nuclear Information System (INIS)

    Carew, J.A.; Collins, M.F.; Kennedy, A.R.

    1988-01-01

    Bacterial endotoxins (lipopolysaccharides) were found to suppress X-ray-induced malignant transformation of C3H/10T1/2 cells. Endotoxins were effective if present either throughout the 6-week transformation assay period, or for the final 4-week phase, but not when present only for the initial 2-week phase. Neither growth nor survival of C3H/10T1/2 cells, or a radiation-transformed cell line derived from them, were affected by endotoxins. Also, the endotoxins did not affect the formation of foci by the radiation transformed cells when these cells were co-cultured with untransformed cells. These results suggest that endotoxins exert their effect directly upon the transformation process itself, perhaps at a 'late' step in the conversion of an untransformed to a transformed cell. (author)

  19. Inhibition of radiation-induced transformation in vitro by bacterial endotoxins

    Energy Technology Data Exchange (ETDEWEB)

    Carew, J A; Collins, M F; Kennedy, A R

    1988-05-01

    Bacterial endotoxins (lipopolysaccharides) were found to suppress X-ray-induced malignant transformation of C3H/10T1/2 cells. Endotoxins were effective if present either throughout the 6-week transformation assay period, or for the final 4-week phase, but not when present only for the initial 2-week phase. Neither growth nor survival of C3H/10T1/2 cells, or a radiation-transformed cell line derived from them, were affected by endotoxins. Also, the endotoxins did not affect the formation of foci by the radiation transformed cells when these cells were co-cultured with untransformed cells. These results suggest that endotoxins exert their effect directly upon the transformation process itself, perhaps at a 'late' step in the conversion of an untransformed to a transformed cell.

  20. PBL as a Tool for Staff Development in the Educational Transformation towards PBL

    DEFF Research Database (Denmark)

    Du, Xiangyun; Kolmos, Anette; Qvist, Palle

    2007-01-01

    Abstract Worldwide, the philosophy of problem based and project based learning (PBL) has been implemented as educational models in diverse practice of teaching and learning. Recent years have witnessed more and more educational transformations towards PBL. Despite the diversity of approaches...... and practices in the process of organizational transformation, staff development remains one of key elements in the transformation process in order to teach staff new PBL practice.. A growing body of literature discussing the role of facilitation in PBL, implementation of PBL at different levels in educational...... practice, PBL online; however, little has been documented on the practice of staff development in PBL, especially through online education in the form of PBL. This paper presents the experiences and reflections of using PBL online as a strategy for staff development based on the practice...

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

    Directory of Open Access Journals (Sweden)

    Enas R Yassin

    2009-08-01

    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.

  2. Leadership Development: Key to Success for Navy Civilian Workforce Transformation

    National Research Council Canada - National Science Library

    Nason, Ronald O

    2008-01-01

    ... for recapitalization through aggressive streamlining of naval business processes. This paper will address how leadership can be developed and applied toward ensuring the success of Sea Enterprise and achieving the goals of naval transformation...

  3. Transforming RN education: clinical learning and clinical knowledge development.

    Science.gov (United States)

    Benner, P

    1993-04-01

    Transforming RN education has the potential for transforming clinical teaching and learning for all students. The returning RN student offers possibilities for clinical learning that the generic student does not have, but this should not cause us to limit the returning RN student to the generic level. Where possible innovative programs should be developed to move the RN student from baccalaureate level to the Master's level. As educators, we should take the opportunity to increase the numbers of nurses who are educationally prepared to move into advanced levels of practice. The returning RN student offers a rich human resource for the profession, and a rich resource for improving our clinical teaching as well as our practice.

  4. Cell penetrating peptides to dissect host-pathogen protein-protein interactions in Theileria -transformed leukocytes

    KAUST Repository

    Haidar, Malak

    2017-09-08

    One powerful application of cell penetrating peptides is the delivery into cells of molecules that function as specific competitors or inhibitors of protein-protein interactions. Ablating defined protein-protein interactions is a refined way to explore their contribution to a particular cellular phenotype in a given disease context. Cell-penetrating peptides can be synthetically constrained through various chemical modifications that stabilize a given structural fold with the potential to improve competitive binding to specific targets. Theileria-transformed leukocytes display high PKA activity, but PKAis an enzyme that plays key roles in multiple cellular processes; consequently genetic ablation of kinase activity gives rise to a myriad of confounding phenotypes. By contrast, ablation of a specific kinase-substrate interaction has the potential to give more refined information and we illustrate this here by describing how surgically ablating PKA interactions with BAD gives precise information on the type of glycolysis performed by Theileria-transformed leukocytes. In addition, we provide two other examples of how ablating specific protein-protein interactions in Theileria-infected leukocytes leads to precise phenotypes and argue that constrained penetrating peptides have great therapeutic potential to combat infectious diseases in general.

  5. Invited review: mesenchymal progenitor cells in intramuscular connective tissue development.

    Science.gov (United States)

    Miao, Z G; Zhang, L P; Fu, X; Yang, Q Y; Zhu, M J; Dodson, M V; Du, M

    2016-01-01

    The abundance and cross-linking of intramuscular connective tissue contributes to the background toughness of meat, and is thus undesirable. Connective tissue is mainly synthesized by intramuscular fibroblasts. Myocytes, adipocytes and fibroblasts are derived from a common pool of progenitor cells during the early embryonic development. It appears that multipotent mesenchymal stem cells first diverge into either myogenic or non-myogenic lineages; non-myogenic mesenchymal progenitors then develop into the stromal-vascular fraction of skeletal muscle wherein adipocytes, fibroblasts and derived mesenchymal progenitors reside. Because non-myogenic mesenchymal progenitors mainly undergo adipogenic or fibrogenic differentiation during muscle development, strengthening progenitor proliferation enhances the potential for both intramuscular adipogenesis and fibrogenesis, leading to the elevation of both marbling and connective tissue content in the resulting meat product. Furthermore, given the bipotent developmental potential of progenitor cells, enhancing their conversion to adipogenesis reduces fibrogenesis, which likely results in the overall improvement of marbling (more intramuscular adipocytes) and tenderness (less connective tissue) of meat. Fibrogenesis is mainly regulated by the transforming growth factor (TGF) β signaling pathway and its regulatory cascade. In addition, extracellular matrix, a part of the intramuscular connective tissue, provides a niche environment for regulating myogenic differentiation of satellite cells and muscle growth. Despite rapid progress, many questions remain in the role of extracellular matrix on muscle development, and factors determining the early differentiation of myogenic, adipogenic and fibrogenic cells, which warrant further studies.

  6. Influence of cell dissociation procedures on the tumorigenicity of Simian Virus 40 transformed fibroblasts

    International Nuclear Information System (INIS)

    Tenforde, T.S.; Risius, J.; Beckmann, A.; Tobias, C.A.; Gurney, E.

    1975-11-01

    Mouse fibroblasts transformed by Simian Virus 40 (SV40) were examined for tumor forming ability in syngeneic BALB/c mice following dissociation from tissue culture dishes by two procedures. A significantly greater in vivo proliferative capacity was observed for cells dissociated by the tryspin-EDTA procedure, with the injected cell dose for tumor production in 50 percent of recipient mice (the TPD 50 ) being 16-fold lower than the TPD 50 for cells dissociated by the EDTA procedure. Host immunosuppression with 300 rad whole-body γ irradiation led to a significant 7-fold decrease in the TPD 50 for cells dissociated by the EDTA procedure, while no significant decrease in TPD 50 was observed for cells dissociated by the tryspin-EDTA procedure

  7. Transforming Leadership Development for Significant Learning.

    Science.gov (United States)

    Owen, Julie E

    2015-01-01

    Leadership education is undergoing a transformation where powerful pedagogies and emerging knowledge about the scholarship of teaching and learning supplant long held and often-outmoded practices of leadership education. This transformation requires new commitments to evidence-based practice, critical consciousness, and more complex understanding of the levers of leadership learning. © 2015 Wiley Periodicals, Inc., A Wiley Company.

  8. Development of road infrastructure as a tool of transforming Ibiono ...

    African Journals Online (AJOL)

    Global Journal of Social Sciences ... Development of road infrastructure as a tool of transforming Ibiono Ibom local government area. V Umoren ... The improvement of transportation network in the rural area in this regard becomes imperative.

  9. Absence of PDGF-induced, PKC-independent c-fos expression in a chemically transformed C3H/10T1/2 cell clone.

    Science.gov (United States)

    Vassbotn, F S; Skar, R; Holmsen, H; Lillehaug, J R

    1992-09-01

    The effect of platelet-derived growth factor (PDGF) on c-fos mRNA transcription was studied in the immortalized mouse embryo fibroblast C3H/10T1/2 Cl 8 (10T1/2) cells and the chemically transformed, tumorigenic subclone C3H/10T1/2 Cl 16 (Cl 16). In the 10T1/2 cells as well as the Cl 16 subclone, the dose-dependent PDGF stimulation of c-fos mRNA synthesis was similar in both logarithmically growing and confluent cultures. c-fos mRNA was induced severalfold by 12-O-tetradecanoylphorbol-13-acetate (TPA) in both 10T1/2 and Cl 16. Down-regulation of protein kinase C (PKC) activity by TPA pretreatment inhibited PDGF-stimulated c-fos mRNA expression in Cl 16 cells but did not affect this induction in the 10T1/2 cells. This inhibition was not a general phenomenon of 3-methylcholanthrene-mediated transformation of 10T1/2 cells since experiments with another transformed 10T1/2 cell clone, C3H/10T1/2 TPA 482, gave qualitatively the same results as the 10T1/2 cells. Receptor binding experiments showed that the nontransformed and transformed cells had a comparable number of PDGF receptors, 1.3 x 10(5) and 0.7 x 10(5) receptors per cell, respectively. Furthermore, cAMP-induced c-fos expression induced by forskolin is formerly shown to be independent of PKC down-regulation. In our experiments, forskolin induced c-fos expression in both clones. However, PKC down-regulation inhibited the forskolin-induced c-fos expression in Cl 16 cells. This apparently demonstrates cross talk between PKC and PKA in the c-fos induction pathway. The present results provide evidence for an impaired mechanism for activating c-fos expression through PKC-independent, PDGF-induced signal transduction in the chemically transformed Cl 16 fibroblasts compared to that in nontransformed 10T1/2 cells.

  10. Transforming growth factor-beta, but not ciliary neurotrophic factor, inhibits DNA synthesis of adrenal medullary cells in vitro

    DEFF Research Database (Denmark)

    Wolf, N; Krohn, K; Bieger, S

    1999-01-01

    by the neuroendocrine chromaffin cells, which also express the transforming growth factor-beta receptor type II. In contrast to the developmentally related sympathetic neurons, chromaffin cells continue to proliferate throughout postnatal life. Using 5-bromo-2'-deoxyuridine pulse labeling and tyrosine hydroxylase...... immunocytochemistry as a marker for young postnatal rat chromaffin cells, we show that treatment with fibroblast growth factor-2 (1 nM) and insulin-like growth factor-II (10 nM) increased the fraction of 5-bromo-2'-deoxyuridine-labeled nuclei from 1% to about 40% of the cells in the absence of serum. In the presence...... of fibroblast growth factor-2 and insulin-like growth factor-II, transforming growth factor-beta1 (0.08 nM) reduced 5-bromo-2'-deoxyuridine labeling by about 50%, without interfering with chromaffin cell survival or death. Doses lower and higher than 0.08 nM were less effective. Similar effects were seen...

  11. Transforming Growth Factor-β Drives the Transendothelial Migration of Hepatocellular Carcinoma Cells.

    Science.gov (United States)

    Koudelkova, Petra; Costina, Victor; Weber, Gerhard; Dooley, Steven; Findeisen, Peter; Winter, Peter; Agarwal, Rahul; Schlangen, Karin; Mikulits, Wolfgang

    2017-10-10

    The entry of malignant hepatocytes into blood vessels is a key step in the dissemination and metastasis of hepatocellular carcinoma (HCC). The identification of molecular mechanisms involved in the transmigration of malignant hepatocytes through the endothelial barrier is of high relevance for therapeutic intervention and metastasis prevention. In this study, we employed a model of hepatocellular transmigration that mimics vascular invasion using hepatic sinusoidal endothelial cells and malignant hepatocytes evincing a mesenchymal-like, invasive phenotype by transforming growth factor (TGF)-β. Labelling of respective cell populations with various stable isotopes and subsequent mass spectrometry analyses allowed the "real-time" detection of molecular changes in both transmigrating hepatocytes and endothelial cells. Interestingly, the proteome profiling revealed 36 and 559 regulated proteins in hepatocytes and endothelial cells, respectively, indicating significant changes during active transmigration that mostly depends on cell-cell interaction rather than on TGF-β alone. Importantly, matching these in vitro findings with HCC patient data revealed a panel of common molecular alterations including peroxiredoxin-3, epoxide hydrolase, transgelin-2 and collectin 12 that are clinically relevant for the patient's survival. We conclude that hepatocellular plasticity induced by TGF-β is crucially involved in blood vessel invasion of HCC cells.

  12. Concurrent Presentation of Erythrodermic Lichen Planus and Squamous Cell Carcinoma: Coincidence or Malignant Transformation?

    Science.gov (United States)

    Ali, Neema M; Bhat, Ramesh; Rao, Shwetha B

    2015-01-01

    Lichen planus is a common papulosquamous disorder affecting about 1-2% of the population, neoplastic transformation of cutaneous lichen planus lesions occurs very rarely. A 40 year old female patient presented with a 1 year history of developing multiple, itchy, pigmented lesions over both lower legs which gradually spread to involve the whole body. A few tense bullae were seen on the extremities. An erythematous fleshy lesion was seen on the upper aspect of the left buttock. Skin biopsy from a plaque on the right forearm showed features suggestive of lichen planus. Skin biopsy of a bullae showed a sub epidermal bulla filled with a mixed inflammatory infiltrate. Direct immunofluorescence revealed no immunoreactants along the basement membrane zone. A diagnosis of erythrodermic lichen planus with bullous lichen planus was made. Biopsy of fleshy lesion of left buttock revealed a moderately differentiated squamous cell carcinoma. Erythrodermic lichen planus with bullous lesions and secondary squamous cell carcinoma; these occurences in a single patient is extremely rare and has not been previously reported to the best of our knowledge.

  13. Study on oxidative lipid and DNA damages in the malignant transformed BEP2D cells induced by α-particle exposure

    International Nuclear Information System (INIS)

    Gou Qiao; Wang Chunyan; Zhang Cuilan; Tong Peng; Su Xu

    2012-01-01

    Objective: To investigate the mechanism of malignant transformation in human bronchial epithelial cell line BEP2D exposed to α-particles. Methods: The levels of intracellular ROS and malonaldehyde (MDA) in BEP2D, RH22 (passage 22 of α-particle-irradiated BEP2D cells) and BERP35T-1 cells (derived from nude mice bearing malignant transformed cells generated from the passage 35 of α-particle-irradiated BEP2D cells) were assayed with DCFH-DA and MDA kit, respectively. The expressions of 8-OH-dG and γ-H2AX in BEP2D, RH23 (passage 23 of α-particle-irradiated BEP2D cells) and BERP35T-1 cells were also measured with immunocytochemistry and immunofluorescence staining. Results: Compared to BEP2D cells, the levels of ROS (t=4.30 and 3.94, P<0.05) and MDA (t=4.89 and 15.10, P<0.05) increased in RH22 and BERP35T-1 cells. The expressions of 8-OH-dG (t=3.80 and 2.92, P<0.05) and γ-H2AX (t=7.61 and 12.67, P<0.05) in RH23 and BERP35T-1 cells were also higher than those in BEP2D cells. Conclusions: Oxidative stress induces lipid peroxidation and DNA damage leading to genomic instability, which could contribute to cellular malignant transforming process in the human bronchial epithelial cell line BEP2D with α-particle exposure. (authors)

  14. Expression and autoregulation of transforming growth factor beta receptor mRNA in small-cell lung cancer cell lines

    DEFF Research Database (Denmark)

    Nørgaard, P; Spang-Thomsen, M; Poulsen, H S

    1996-01-01

    In small-cell lung cancer cell lines resistance to growth inhibition by transforming growth factor (TGF)-beta 1, was previously shown to correlate with lack of TGF-beta receptor I (RI) and II (RII) proteins. To further investigate the role of these receptors, the expression of mRNA for RI, RII...... and beta-glycan (RIII) was examined. The results showed that loss of RII mRNA correlated with TGF-beta 1 resistance. In contrast, RI-and beta-glycan mRNA was expressed by all cell lines, including those lacking expression of these proteins. According to Southern blot analysis, the loss of type II m......RNA was not due to gross structural changes in the gene. The effect of TGF-beta 1 on expression of TGF-beta receptor mRNA (receptor autoregulation) was examined by quantitative Northern blotting in four cell lines with different expression of TGF-beta receptor proteins. In two cell lines expressing all three TGF...

  15. The PDZ domain binding motif (PBM) of human T-cell leukemia virus type 1 Tax can be substituted by heterologous PBMs from viral oncoproteins during T-cell transformation.

    Science.gov (United States)

    Aoyagi, Tomoya; Takahashi, Masahiko; Higuchi, Masaya; Oie, Masayasu; Tanaka, Yuetsu; Kiyono, Tohru; Aoyagi, Yutaka; Fujii, Masahiro

    2010-04-01

    Several tumor viruses, such as human T-cell leukemia virus (HTLV), human papilloma virus (HPV), human adenovirus, have high-oncogenic and low-oncogenic subtypes, and such subtype-specific oncogenesis is associated with the PDZ-domain binding motif (PBM) in their transforming proteins. HTLV-1, the causative agent of adult T-cell leukemia, encodes Tax1 with PBM as a transforming protein. The Tax1 PBM was substituted with those from other oncoviruses, and the transforming activity was examined. Tax1 mutants with PBM from either HPV-16 E6 or adenovirus type 9 E4ORF1 are fully active in the transformation of a mouse T-cell line from interleukin-2-dependent growth into independent growth. Interestingly, one such Tax1 PBM mutant had an extra amino acid insertion derived from E6 between PBM and the rest of Tax1, thus suggesting that the amino acid sequences of the peptides between PBM and the rest of Tax1 and the numbers only slightly affect the function of PBM in the transformation. Tax1 and Tax1 PBM mutants interacted with tumor suppressors Dlg1 and Scribble with PDZ-domains. Unlike E6, Tax1 PBM mutants as well as Tax1 did not or minimally induced the degradations of Dlg1 and Scribble, but instead induced their subcellular translocation from the detergent-soluble fraction into the insoluble fraction, thus suggesting that the inactivation mechanism of these tumor suppressor proteins is distinct. The present results suggest that PBMs of high-risk oncoviruses have a common function(s) required for these three tumor viruses to transform cells, which is likely associated with the subtype-specific oncogenesis of these tumor viruses.

  16. Galangin inhibits human osteosarcoma cells growth by inducing transforming growth factor-β1-dependent osteogenic differentiation.

    Science.gov (United States)

    Liu, Chunhong; Ma, Mingming; Zhang, Junde; Gui, Shaoliu; Zhang, Xiaohai; Xue, Shuangtao

    2017-05-01

    Osteosarcoma is the most common primary malignancy of the musculoskeletal system, and is associated with excessive proliferation and poor differentiation of osteoblasts. Currently, despite the use of traditional chemotherapy and radiotherapy, no satisfactory and effective agent has been developed to treat the disease. Herein, we found that a flavonoid natural product, galangin, could significantly attenuate human osteosarcoma cells proliferation, without causing obvious cell apoptosis. Moreover, galangin enhanced the expression of osteoblast differentiation markers (collagen type I, alkaline phosphatase, osteocalcin and osteopontin) remarkably and elevated the alkaline phosphatase activity in human osteosarcoma cells. And galangin could also attenuated osteosarcoma growth in vivo. These bioactivities of galangin resulted from its selective activation of the transforming growth factor (TGF)-β1/Smad2/3 signaling pathway, which was demonstrated by pathway blocking experiments. These findings suggested that galangin could be a promising agent to treat osteosarcoma. In addition, targeting TGF-β1 to induce osteogenic differentiation might represent a novel therapeutic strategy to treat osteosarcoma with minimal side effects. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  17. USING THE PRINCIPLES OF TRANSFORMATION IN THE DEVELOPMENT OF NEW DESIGN CLOTHES-MAKING FOR WOMEN

    Directory of Open Access Journals (Sweden)

    IROVAN Marcela

    2016-05-01

    Full Text Available The transformable garments represent an actual group in the assortment of contemporary clothing, providing wide possibilities of obtaining multifunctional shapes. The work presents the results of theoretical and applied research in the design of garments with flexible structure for women. The scope of study consists in the analysis of possibilities to develop modern assortments of garments for women by using morphological transformation techniques. The transformable products include an ensemble of garments designed with diverse techniques and methods, both traditional and non-traditional. The morphological transformation techniques are based on the principles of reconstruction and transformation, facilitating the transformation of one product shape into another and transformation of elements in the interior of the same shape. The study has defined several development directions for transformable products in the actual wardrobe: products made with two different texture, color and structure faces; products with attachable or detachable elements; products with a separate structure that by location, wrapping or connection of elements allow to obtain diverse shapes; products with changing shapes with the aid of various types of accessories; multifunctional product elements. The experimental studies were aimed at the elaboration of assortments of garments for women by applying the morphological transformation procedures with elaboration and manufacturing of models of transformable skirts for women. The transformable models demonstrate the universality of products, their functional possibilities, capacity to change the external appearance and aesthetic properties. When designing women’s skirts one may use all types of transformation, several types of transformation may be used in one product simultaneously thus achieving several functional scopes.

  18. Action-embedded transformational leadership in self-managing global information systems development teams

    NARCIS (Netherlands)

    Eseryel, U. Yeliz; Eseryel, Deniz

    While software development teams are becoming more and more distributed around the globe, most software development methodologies used by global teams prescribe self-managing teams. Transformational leadership is the key to successful information systems development and use for competitive

  19. 2D-DIGE and MALDI TOF/TOF MS analysis reveal that small GTPase signaling pathways may play an important role in cadmium-induced colon cell malignant transformation

    International Nuclear Information System (INIS)

    Lu, Jian; Zhou, Zhongping; Zheng, Jianzhou; Zhang, Zhuyi; Lu, Rongzhu; Liu, Hanqing; Shi, Haifeng; Tu, Zhigang

    2015-01-01

    Cadmium is a toxic heavy metal present in the environment and in industrial materials. Cadmium has demonstrated carcinogenic activity that induces cell transformation, but how this occurs is unclear. We used 2D-DIGE and MALDI TOF/TOF MS combined with bioinformatics and immunoblotting to investigate the molecular mechanism of cadmium transformation. We found that small GTPases were critical for transformation. Additionally, proteins involved in mitochondrial transcription, DNA repair, and translation also had altered expression patterns in cadmium treated cells. Collectively, our results suggest that activation of small GTPases contributes to cadmium-induced transformation of colon cells. - Highlights: • Colon epithelial cell line is firstly successfully transformed by cadmium. • 2D-DIGE is applied to visualize the differentially expressed proteins. • RhoA plays an important role in cadmium induced malignant transformation. • Bioinformatic and experimental methods are combined to explore new mechanisms.

  20. 2D-DIGE and MALDI TOF/TOF MS analysis reveal that small GTPase signaling pathways may play an important role in cadmium-induced colon cell malignant transformation

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Jian, E-mail: lujian@ujs.edu.cn [School of Medicine, Jiangsu University, Zhenjiang 212013 (China); Institute of Life Sciences, Jiangsu University, Zhenjiang 212013 (China); Zhou, Zhongping [School of Medicine, Jiangsu University, Zhenjiang 212013 (China); Institute of Life Sciences, Jiangsu University, Zhenjiang 212013 (China); Zheng, Jianzhou [Department of Respiration Medicine, Changzhou No.2 People' s Hospital, Changzhou 213003 (China); Zhang, Zhuyi [School of Medicine, Jiangsu University, Zhenjiang 212013 (China); Institute of Life Sciences, Jiangsu University, Zhenjiang 212013 (China); Lu, Rongzhu [School of Medicine, Jiangsu University, Zhenjiang 212013 (China); Liu, Hanqing [School of Pharmacy, Jiangsu University, Zhenjiang 212013 (China); Shi, Haifeng [Institute of Life Sciences, Jiangsu University, Zhenjiang 212013 (China); Tu, Zhigang, E-mail: tuzg_ujs@ujs.edu.cn [Institute of Life Sciences, Jiangsu University, Zhenjiang 212013 (China)

    2015-10-01

    Cadmium is a toxic heavy metal present in the environment and in industrial materials. Cadmium has demonstrated carcinogenic activity that induces cell transformation, but how this occurs is unclear. We used 2D-DIGE and MALDI TOF/TOF MS combined with bioinformatics and immunoblotting to investigate the molecular mechanism of cadmium transformation. We found that small GTPases were critical for transformation. Additionally, proteins involved in mitochondrial transcription, DNA repair, and translation also had altered expression patterns in cadmium treated cells. Collectively, our results suggest that activation of small GTPases contributes to cadmium-induced transformation of colon cells. - Highlights: • Colon epithelial cell line is firstly successfully transformed by cadmium. • 2D-DIGE is applied to visualize the differentially expressed proteins. • RhoA plays an important role in cadmium induced malignant transformation. • Bioinformatic and experimental methods are combined to explore new mechanisms.

  1. Persistence of sister chromatid exchanges and in vitro morphological transformation of Syrian hamster fetal cells by chemical and physical carcinogens

    International Nuclear Information System (INIS)

    Popescu, N.C.; Amsbaugh, S.C.; DiPaolo, J.A.

    1985-01-01

    The induction of neoplastic cell transformation is closely associated with DNA alterations which occur shortly after carcinogen exposure. Sister chromatid exchange (SCE) formation is a sensitive indicator of carcinogen-DNA interaction and correlates with the induction of morphological cell transformation. The persistence of lesions generating SCE produced by chemical and physical carcinogens and its relevance to the induction of morphologic transformation was evaluated in coordinated experiments with cultured Syrian hamster fetal cells (HFC). Exponentially growing HFC were exposed for 1 h to benzo[a]pyrene (BP), methyl-methanesulfonate (MMS), cis-platinum (II) diaminedichloride (cis Pt II), N-methyl-N'-nitrosourea (MNU), mitomycin C (MMC), N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), N-acetoxy-2-fluorenyl-acetamide (AcAAF) or u.v. light irradiated. SCE analysis demonstrates that for a period of 48 h after carcinogen exposure, during which time the cells undergo at least four replicative cycles, DNA damage generating SCE induced by all chemical carcinogens either persisted or was partially removed, whereas u.v.-induced lesions were completely removed. An elevated SCE frequency persisted after two additional cell cycles after treatment with BP, AcAAF or MMC without increased cell lethality as compared to other carcinogens whose lesions were completely eliminated during the same period

  2. An Epstein-Barr virus anti-apoptotic protein constitutively expressed in transformed cells and implicated in burkitt lymphomagenesis: the Wp/BHRF1 link.

    Directory of Open Access Journals (Sweden)

    Gemma L Kelly

    2009-03-01

    Full Text Available Two factors contribute to Burkitt lymphoma (BL pathogenesis, a chromosomal translocation leading to c-myc oncogene deregulation and infection with Epstein-Barr virus (EBV. Although the virus has B cell growth-transforming ability, this may not relate to its role in BL since many of the transforming proteins are not expressed in the tumor. Mounting evidence supports an alternative role, whereby EBV counteracts the high apoptotic sensitivity inherent to the c-myc-driven growth program. In that regard, a subset of BLs carry virus mutants in a novel form of latent infection that provides unusually strong resistance to apoptosis. Uniquely, these virus mutants use Wp (a viral promoter normally activated early in B cell transformation and express a broader-than-usual range of latent antigens. Here, using an inducible system to express the candidate antigens, we show that this marked apoptosis resistance is mediated not by one of the extended range of EBNAs seen in Wp-restricted latency but by Wp-driven expression of the viral bcl2 homologue, BHRF1, a protein usually associated with the virus lytic cycle. Interestingly, this Wp/BHRF1 connection is not confined to Wp-restricted BLs but appears integral to normal B cell transformation by EBV. We find that the BHRF1 gene expression recently reported in newly infected B cells is temporally linked to Wp activation and the presence of W/BHRF1-spliced transcripts. Furthermore, just as Wp activity is never completely eclipsed in in vitro-transformed lines, low-level BHRF1 transcripts remain detectable in these cells long-term. Most importantly, recognition by BHRF1-specific T cells confirms that such lines continue to express the protein independently of any lytic cycle entry. This work therefore provides the first evidence that BHRF1, the EBV bcl2 homologue, is constitutively expressed as a latent protein in growth-transformed cells in vitro and, in the context of Wp-restricted BL, may contribute to virus

  3. Regulation of Hematopoietic Cell Development and Function Through Phosphoinositides

    Directory of Open Access Journals (Sweden)

    Mila Elich

    2018-05-01

    Full Text Available One of the most paramount receptor-induced signal transduction mechanisms in hematopoietic cells is production of the lipid second messenger phosphatidylinositol(3,4,5trisphosphate (PIP3 by class I phosphoinositide 3 kinases (PI3K. Defective PIP3 signaling impairs almost every aspect of hematopoiesis, including T cell development and function. Limiting PIP3 signaling is particularly important, because excessive PIP3 function in lymphocytes can transform them and cause blood cancers. Here, we review the key functions of PIP3 and related phosphoinositides in hematopoietic cells, with a special focus on those mechanisms dampening PIP3 production, turnover, or function. Recent studies have shown that beyond “canonical” turnover by the PIP3 phosphatases and tumor suppressors phosphatase and tensin homolog (PTEN and SH2 domain-containing inositol-5-phosphatase-1 (SHIP-1/2, PIP3 function in hematopoietic cells can also be dampened through antagonism with the soluble PIP3 analogs inositol(1,3,4,5tetrakisphosphate (IP4 and inositol-heptakisphosphate (IP7. Other evidence suggests that IP4 can promote PIP3 function in thymocytes. Moreover, IP4 or the kinases producing it limit store-operated Ca2+ entry through Orai channels in B cells, T cells, and neutrophils to control cell survival and function. We discuss current models for how soluble inositol phosphates can have such diverse functions and can govern as distinct processes as hematopoietic stem cell homeostasis, neutrophil macrophage and NK cell function, and development and function of B cells and T cells. Finally, we will review the pathological consequences of dysregulated IP4 activity in immune cells and highlight contributions of impaired inositol phosphate functions in disorders such as Kawasaki disease, common variable immunodeficiency, or blood cancer.

  4. Histologic transformation from adenocarcinoma to both small cell lung cancer and squamous cell carcinoma after treatment with gefitinib: A case report.

    Science.gov (United States)

    Yao, Yufeng; Zhu, Zhouyu; Wu, Yimin; Chai, Ying

    2018-05-01

    In the past decade, epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) treatment had been an important therapy for treating advanced EGFR-mutated lung cancer patients. However, a large number of these patients with EGFR-TKIs treatment always acquired resistance to these drugs in one year. The histologic transformation is an important resistance mechanism. Here we reported a 41-year-old man with EGFR-mutated lung adenocarcinoma and he showed histologic transformation to both small-cell lung cancer (SCLC) and squamous cell carcinoma (SCC) after treatment of gefitinib. A case of EGFR-mutated lung cancer. Medical thoracoscopy examination was performed and the patient was diagnosed as a EGFR-mutated lung adenocarcinoma. Then gefitinib was administered orally at a dose of 250 mg daily. The patient received treatment with chemotherapy (etoposide 0.1 g day 2-5 +  cis-platinum 30 mg day 2-4) after acquiring resistance to gefitinib. The patient died in April 2017 that survived for 32 months from lung cancer was found for the first time. To the best of our knowledge, it is the first case of EGFR-mutated lung adenocarcinoma transforming to both SCLC and SCC which was treated with and responded to gefitinib.

  5. Plant lectin can target receptors containing sialic acid, exemplified by podoplanin, to inhibit transformed cell growth and migration.

    Directory of Open Access Journals (Sweden)

    Jhon Alberto Ochoa-Alvarez

    Full Text Available Cancer is a leading cause of death of men and women worldwide. Tumor cell motility contributes to metastatic invasion that causes the vast majority of cancer deaths. Extracellular receptors modified by α2,3-sialic acids that promote this motility can serve as ideal chemotherapeutic targets. For example, the extracellular domain of the mucin receptor podoplanin (PDPN is highly O-glycosylated with α2,3-sialic acid linked to galactose. PDPN is activated by endogenous ligands to induce tumor cell motility and metastasis. Dietary lectins that target proteins containing α2,3-sialic acid inhibit tumor cell growth. However, anti-cancer lectins that have been examined thus far target receptors that have not been identified. We report here that a lectin from the seeds of Maackia amurensis (MASL with affinity for O-linked carbohydrate chains containing sialic acid targets PDPN to inhibit transformed cell growth and motility at nanomolar concentrations. Interestingly, the biological activity of this lectin survives gastrointestinal proteolysis and enters the cardiovascular system to inhibit melanoma cell growth, migration, and tumorigenesis. These studies demonstrate how lectins may be used to help develop dietary agents that target specific receptors to combat malignant cell growth.

  6. Development of nanobiomarkers for use in sickle cell anemia

    International Nuclear Information System (INIS)

    Santos, Elen Goncalves dos

    2009-01-01

    Luminescent materials, such as the rare earth's complex, can be used as markers in cytology and immunology, being also used as luminescent bio markers, once the development of these nano materials create new possibilities to many fields, particularly in diagnostic medicine. Besides, it establishes one kind of fluorescent probes, for which there are no equivalent organic molecules. Due to its potential in market's application, the objective of this work was to develop luminescent materials, allowing the use of these super molecules of lanthanides as markers for the detection of Sickle Cell Disease (HbS). Six luminescent markers were developed and marked on rare's earth base. The main methodology used for the detection of HbS was fluoroimmunoassay, which is already used in investigation of enzymes, antibodies, cells, hormones, and so on. During this work, absorption's spectrum in the infrared by Fourier's Transform (FTIR) was also used to detect the HbS. The studied methods were applied for the diagnosis of this disease, which has genetic origin, very typical of the hemoglobin-pathology group and considered to be a public health problem in Brazil (ANVISA). When early diagnosed, Sickle Cell Disease (SCD) has a significant decrease in morbidity and mortality. Comparing the obtained results to the already known methodologies, it was possible to conclude that they are viable methods to detect HbS. Besides, when totally developed, these methods will contribute to the production of Sickle Cell Anemia's diagnostic, and they will have impact in Sao Paulo state's public measures, as well as in Brazil's ones. (author)

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

    International Nuclear Information System (INIS)

    Han, Chang Yeob; Hien, Tran Thi; Lim, Sung Chul; Kang, Keon Wook

    2011-01-01

    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/cm 2 ) 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.

  8. Transformation of Aspergillus parasiticus with a homologous gene (pyrG) involved in pyrimidine biosynthesis

    International Nuclear Information System (INIS)

    Skory, C.D.; Horng, J.S.; Pestka, J.J.; Linz, J.E.

    1990-01-01

    The lack of efficient transformation methods for aflatoxigenic Aspergillus parasiticus has been a major constraint for the study of aflatoxin biosynthesis at the genetic level. A transformation system with efficiencies of 30 to 50 stable transformants per μg of DNA was developed for A. parasiticus by using homologous pyrG gene. The pyrG gene from A. parasiticus was isolated by in situ plaque hybridization of a lambda genomic DNA library. Uridine auxotrophs of A. parasiticus ATCC 36537, a mutant blocked in aflatoxin biosynthesis, were isolated by selection on 5-fluoroorotic acid following nitrosoguanidine mutagenesis. Isolates with mutations in the pyrG gene resulting in elimination of orotidine monophosphate (OMP) decarboxylase activity were detected by assaying cell extracts for their ability to convert [ 14 C]OMP to [ 14 C]UMP. Transformation of A. parasiticus pyrG protoplasts with the homologous pyrG gene restored the fungal cells to prototrophy. Enzymatic analysis of cell extracts of transformant clones demonstrated that these extracts had the ability to convert [ 14 C]OMP to [ 14 C]UMP. Southern analysis of DNA purified from transformant clones indicated that both pUC19 vector sequences and pyrG sequences were integrated into the genome. The development of this pyrG transformation system should allow cloning of the aflatoxin-biosynthetic genes, which will be useful in studying the regulation of aflatoxin biosynthesis and may ultimately provide a means for controlling aflatoxin production in the field

  9. 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.

  10. Comparison and validation of Fourier transform infrared spectroscopic methods for monitoring secondary cell wall cellulose from cotton fibers

    Science.gov (United States)

    The amount of secondary cell wall (SCW) cellulose in the fiber affects the quality and commercial value of cotton. Accurate assessments of SCW cellulose are essential for improving cotton fibers. Fourier Transform Infrared (FT-IR) spectroscopy enables distinguishing SCW from other cell wall componen...

  11. Technology as a factor of identity transformation: development of HOMO TECHNOLOGIES

    Directory of Open Access Journals (Sweden)

    Vadim A. Emelin

    2016-03-01

    Full Text Available Based on the understanding of identity as an individual’s identity with the self within the cultural historical chronotope, and experienced as the feeling of belonging/ non-belonging to some communities, controllability/uncontrollability of situations and predictability/non-predictability of events, the paper describes the processes of identity transformation in the course of a technological development. Taken as the initial point, the idea of organ-extension (K. Marx, E. Kapp and technological extension of man (S. Freud, M. McLuhan means that technologies are the extension of a human body and its organs. The processes of technological extension assume a particular scale under condition of information society development, within which computer-, telecommunication-, transport-, bio-, nano- and other high technologies have become an actual cultural historical force that has a power to transform a human. Special attention is paid to the fact that unlike the precedent technologies that have just facilitated some or other human performance, modern technologies of information society do not only change the human topology, widen and expand human natural abilities but also really transform higher mental functions and mediate mental processes and relations between human individuals. Man becomes not only a biological and social creature but also a technological one, i.e. so called HOMO TECHNOLOGICUS. The scale and speed of cultural historical changes make the study of the technological extensions role in the transformation of identity a key point for developing ways of comprehending their role in the life of a modern person, and also for forecasting the evolution of relationship between man and machines in the future.

  12. 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)

  13. Enhanced sensitivity to neoplastic transformation by 137Cs γ-rays of cells in the G2-/M-phase age interval

    International Nuclear Information System (INIS)

    Cao, J.; Wells, R.L.; Elkind, M.M.

    1992-01-01

    C3H mouse 10T1/2 cells, exposed to low doses of fission-spectrum neutrons, have an enhanced frequency of neoplastic transformation if protracted exposures are used (Hill et al. 1982, 1984a, 1985). To explain this anormaly, a biophysical model was proposed (Elkind 1991 a,b). The unique shape and radiobiological properties of cells in and around mitosis, led to the proposal that the sensitive window is mitosis and possible cells just preceding or just following M phase (Elkind 1991a,b). This study was undertaken using 137 Cs γ-rays. The authors found that late G 2- to M-phase 10T1/2 cells have a maximal sensitivity to neoplastic transformation as well as to killing by 137 Cs γ-rays. (author)

  14. On transform coding tools under development for VP10

    Science.gov (United States)

    Parker, Sarah; Chen, Yue; Han, Jingning; Liu, Zoe; Mukherjee, Debargha; Su, Hui; Wang, Yongzhe; Bankoski, Jim; Li, Shunyao

    2016-09-01

    Google started the WebM Project in 2010 to develop open source, royaltyfree video codecs designed specifically for media on the Web. The second generation codec released by the WebM project, VP9, is currently served by YouTube, and enjoys billions of views per day. Realizing the need for even greater compression efficiency to cope with the growing demand for video on the web, the WebM team embarked on an ambitious project to develop a next edition codec, VP10, that achieves at least a generational improvement in coding efficiency over VP9. Starting from VP9, a set of new experimental coding tools have already been added to VP10 to achieve decent coding gains. Subsequently, Google joined a consortium of major tech companies called the Alliance for Open Media to jointly develop a new codec AV1. As a result, the VP10 effort is largely expected to merge with AV1. In this paper, we focus primarily on new tools in VP10 that improve coding of the prediction residue using transform coding techniques. Specifically, we describe tools that increase the flexibility of available transforms, allowing the codec to handle a more diverse range or residue structures. Results are presented on a standard test set.

  15. Effects of cellular non-protein sulfhydryl depletion in radiation induced oncogenic transformation and genotoxicity in mouse C3H 10T1/2 cells

    International Nuclear Information System (INIS)

    Hei, T.K.; Geard, C.R.; Hall, E.J.

    1984-01-01

    A study was made of the effects of cellular non-protein sulfhydryl (NPSH) depletion on cytotoxicity, cell cycle kinetics, oncogenic transformation and sister chromatid exchange (SCE) in C 3 H 10T1/2 cells. Using DL-Buthionine S-R-Sulfoximine (BSO) to deplete thiols, it was found spectrophotometrically that less than 5% of control NPSH level remained in the cells after 24-hour treatment under aerated conditions. Such NPSH depleted cells, when subject to a 3 Gy γ-ray treatment, were found to have no radiosensitizing response either in terms of cell survival or oncogenic transformation. In addition, decreased levels of NPSH had no effect on spontaneous or radiation-induced SCE nor were cell cycle kinetics additionally altered. Therefore, the inability of NPSH depletion to alter γ-ray induced cellular transformation was unrelated to any possible effect of BSO on the cell cycle. These results suggest that such depletion may result in little or no additional oncogenic or genotoxic effects on aerated normal tissues

  16. Battery Charge Equalizer with Transformer Array

    Science.gov (United States)

    Davies, Francis

    2013-01-01

    High-power batteries generally consist of a series connection of many cells or cell banks. In order to maintain high performance over battery life, it is desirable to keep the state of charge of all the cell banks equal. A method provides individual charging for battery cells in a large, high-voltage battery array with a minimum number of transformers while maintaining reasonable efficiency. This is designed to augment a simple highcurrent charger that supplies the main charge energy. The innovation will form part of a larger battery charge system. It consists of a transformer array connected to the battery array through rectification and filtering circuits. The transformer array is connected to a drive circuit and a timing and control circuit that allow individual battery cells or cell banks to be charged. The timing circuit and control circuit connect to a charge controller that uses battery instrumentation to determine which battery bank to charge. It is important to note that the innovation can charge an individual cell bank at the same time that the main battery charger is charging the high-voltage battery. The fact that the battery cell banks are at a non-zero voltage, and that they are all at similar voltages, can be used to allow charging of individual cell banks. A set of transformers can be connected with secondary windings in series to make weighted sums of the voltages on the primaries.

  17. Reduced temperature (22 degrees C) results in enhancement of cell killing and neoplastic transformation in noncycling HeLa x skin fibroblast human hybrid cells irradiated with low-dose-rate gamma radiation

    International Nuclear Information System (INIS)

    Redpath, J.L.; Antoniono, R.J.

    1995-01-01

    The effect of reduced temperature (22 degrees C) or serum deprivation during low-dose-rate (0.66 cGy/min) γ irradiation on cell killing and neoplastic transformation has been examined using the HeLa x skin fibroblast human hybrid cell system. The reduced temperature stops progression of these cells through the cell cycle while serum deprivation slows down cell turnover markedly. The data demonstrate an enhancement in both of the end points when cells are held at 22 degrees C compared to parallel experiments done at 37 degrees C. In operational terms, the decreased survival and increased neoplastic transformation are consistent with our earlier hypothesis of a higher probability of misrepair at reduced temperature. The interpretation that this damage enhancement was associated with the reduced temperature, and not the fact that the cells were noncycling, was supported by the results of experiments performed with cells cultured at 37 degrees C in serum-free medium for 35 h prior to and then during the 12.24 h low-dose-rate radiation exposure. Under these conditions, cell cycle progression, as shown by reduction in growth rate and dual-parameter flow cytometric analysis, was considerable inhibited (cell cycle time increased from 20 h to 40 h), and there was no significant enhancement of cell killing or neoplastic transformation. 23 refs., 2 figs., 1 tab

  18. Recombinant Protein Production and Insect Cell Culture and Process

    Science.gov (United States)

    Spaulding, Glenn F. (Inventor); Goodwin, Thomas J. (Inventor); OConnor, Kim C. (Inventor); Francis, Karen M. (Inventor); Andrews, Angela D. (Inventor); Prewett, Tracey L. (Inventor)

    1997-01-01

    A process has been developed for recombinant production of selected polypeptides using transformed insect cells cultured in a horizontally rotating culture vessel modulated to create low shear conditions. A metabolically transformed insect cell line is produced using the culture procedure regardless of genetic transformation. The recombinant polypeptide can be produced by an alternative process using virtually infected or stably transformed insect cells containing a gene encoding the described polypeptide. The insect cells can also be a host for viral production.

  19. Transforming knowledge across domains in the temporary development spaces

    DEFF Research Database (Denmark)

    Brønnum, Louise

    This paper addresses transformation of knowledge across different knowledge domains and competencies in the Front End of Innovation (FEI) [Koen 2002].We examine the temporary spaces [Clausen, Yoshinaka 2007] that emerge when different knowledge domains are brought into play (implicit or explicit......) in staging innovative concept development. FEI appears as temporary spaces for innovative processes; and studies have pointed out the limited uptake of user knowledge (Elgaard Jensen 2012). This paper will discuss the possibilities and barriers for uptake of user knowledge in FEI in relation...... to the constitutions of these temporary spaces. There seems to be a limited understanding of: how knowledge is transferred and transformed into design objects facilitating a process where knowledge enables innovative thinking across knowledge boundaries. The paper is based on empirical data primarily from case studies...

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

    International Nuclear Information System (INIS)

    Maat, J.

    1978-01-01

    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.)

  1. Epigenomic analysis in a cell-based model reveals the roles of H3K9me3 in breast cancer transformation.

    Science.gov (United States)

    Li, Qing-Lan; Lei, Pin-Ji; Zhao, Quan-Yi; Li, Lianyun; Wei, Gang; Wu, Min

    2017-08-01

    Epigenetic marks are critical regulators of chromatin and gene activity. Their roles in normal physiology and disease states, including cancer development, still remain elusive. Herein, the epigenomic change of H3K9me3, as well as its potential impacts on gene activity and genome stability, was investigated in an in vitro breast cancer transformation model. The global H3K9me3 level was studied with western blotting. The distribution of H3K9me3 on chromatin and gene expression was studied with ChIP-Seq and RNA-Seq, respectively. The global H3K9me3 level decreases during transformation and its distribution on chromatin is reprogrammed. By combining with TCGA data, we identified 67 candidate oncogenes, among which five genes are totally novel. Our analysis further links H3K9me3 with transposon activity, and suggests H3K9me3 reduction increases the cell's sensitivity to DNA damage reagents. H3K9me3 reduction is possibly related with breast cancer transformation by regulating gene expression and chromatin stability during transformation.

  2. Cytogenetic damage, oncogenic transformation and p53 induction in human epithelial cells in response to irradiation

    Science.gov (United States)

    Armitage, Mark

    Ionizing radiation can have several different effects on cells, some are almost instantaneous such as the generation of DNA damage, other cellular responses take a matter of minutes or hours - DNA repair protein induction/activation, and others may take months or even years to be manifested - carcinogenesis. Human epithelial cell lines derived from both normal, non-neoplastic tissues and from a malignant source were cultured in order to examine several effects of ionizing radiation on such cell types. Cells not from a malignant source were previously immortalized by viral infection or by transfection with viral sequences. Simian virus 40 immortalised uroepithelial cells (SV-HUC) were found to be approximately a factor of two fold more radioresistant than cells of malignant origin (T24) in terms of unrepaired clastogenic damage i.e. assessment of micronuclei levels following irradiation. SV-HUC lines unlike T24 cells are non-tumourigenic when inoculated into nude athymic mice. SV-HUC lines proved very resistant to full oncogenic transformation using radiation and chemical carcinogens. However, morphological alterations and decreased anchorage dependant growth was observed in post carcinogen treated cells after appropriate cell culture conditions were utilized. The progression from this phenotype to a fully tumourigenic one was not recorded in this study. The ability of ionizing radiation to induce increased levels of the nuclear phosphoprotein p53 was also assessed using several different cell lines. SV- HUC and T24 cell lines failed to exhibit any increased p53 stabilization following irradiation. One cell line, a human papilloma virus transformed line (HPV) did show an approximate two fold increase of the wild type p53 protein after treatment with radiation. Only the cell line HPV showed any cell cycle delay, resulting in accumulation of cells in the G2/M compartment in post irradiation cell cycle analysis. The status of p53 was also assessed i.e. wild type or

  3. Transforming the organizational culture of a school of nursing through innovative program development.

    Science.gov (United States)

    Lange, Jean W; Ingersoll, Gail; Novotny, Jeanne M

    2008-01-01

    This article illustrates how a grant designed to promote new program development provided a vehicle for organizational transformation. The collaboration surrounding this initiative created a common focus within the school that more effectively channeled its resources and resulted in an unprecedented level of scholarly achievement and recognition. Faculty leveraged the success of this initial grant to procure additional funding for related projects. The importance of partnerships and teamwork were two valuable lessons learned. We believe that our experience is replicable in other schools of nursing interested in organizational transformation. Gibson and Barsade's model of managed change guided the project's implementation and evaluation processes. Recommendations for engaging faculty, gaining support, and developing a collaborative network are discussed in the article, with findings from a stakeholder-focused evaluation demonstrating new program goal achievement as well as the transformative changes that occurred in the organizational culture. A focused, theory-derived program plan, with comprehensive process and outcome evaluation components resulted in a major transformation of one school of nursing. Unanticipated outcomes included renewed synergy among faculty; the development of a preferred vision for the future; scholarly collaboration around a central theme that effectively channeled limited resources and dramatically increased productivity; increased regional and national recognition; and the creation of regional, national, and international partnerships.

  4. Fair-Minded Critical Thinking in Development Education: Reflections on Pedagogies for Transformation

    Science.gov (United States)

    Brown, Eleanor J.

    2014-01-01

    This article discusses research with development education practitioners in Britain and Spain, to explore their conceptions of pedagogical approaches to development education and how these relate to transformative learning theory. Development education is a process designed to generate informed action, which implies the objective of transformation…

  5. The development of a cell-assembly for the treatment of irradiated fuels on a semi-industrial scale

    International Nuclear Information System (INIS)

    Faugeras, P.; Couture, J.; Lefort, G.

    1961-01-01

    The main studies and experiments involved in the development of a cell-assembly for the treatment of irradiated fuels on a semi-industrial scale are described. It must be possible to modify or transform each of these cells without interrupting the rest of the pilot. A full-scale prototype cell (3 x 4 x 6 m) has been built with an α-protection independent of the γ-protection. It features all the main characteristics: tightness to γ losses, dense glass lighting, ventilation. This cell has made possible trials on transfer, remote-controls and tele-dismantling, as well as the development of new methods of rapidly connecting hydraulic circuits. In conclusion the final form is given of the cells selected for the pilot. (author) [fr

  6. Altered sensitivity of system A amino acid transport to ouabain in normal and transformed C3H-10T1/2 cells during the cell cycle

    International Nuclear Information System (INIS)

    Leister, K.J.; Schenerman, M.A.; Racker, E.

    1989-01-01

    Quiescent C3H-10T1/2 mouse fibroblasts that have not undergone any type of stress have a relatively low rate of 2-aminoisobutyrate (Aib) uptake by means of system A, which is primarily energized by the transmembrane Na + chemical gradient potential. System A activity in these cells is not sensitive to ouabain or proton ionophores. In contrast, methylcholanthrene-transformed and cofluent C3H-10T1/2 cells treated with ouabain utilize the membrane potential generated by the Na + , K + -ATPase pump to drive Aib transport by means of system A as shown by the sensitivity of transport activity to ouabain and proton ionophores. Since glucose is present during the assay, the proton ionophores do not affect the availability of ATP, as indicated by the undiminished uptake of 86 Rb + by the Na + , K + -ATPase pump. As cells progress through the G 1 phase of the cell cycle, they show an increased system A activity prior to entry into the S phase, which is also dependent on the electrogenicity of the Na + , K + -ATPase pump. There appears to be in all these cases a qualitative shift in the bioenergetic mechanism for the uptake of Aib as well as a marked quantitative increase in Aib uptake. The high activity after ouabain treatment was sustained in the transformed cells after removal of the ouabain, whereas in the confluent 10T1/2 cells the rate of uptake decayed rapidly, suggesting a difference in the mode of regulation. The authors conclude that transformed cells and normal cells in late G 1 or under stress make use of the membrane potential generated by the Na + , K + -ATPase pump to drive amino acid uptake by means of system A

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

    Directory of Open Access Journals (Sweden)

    Young Bong Choi

    2014-10-01

    Full Text Available 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.

  8. 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

    2014-01-01

    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. PMID:25340740

  9. Loss of a putative tumor suppressor locus after gamma-ray-induced neoplastic transformation of HeLa x Skin fibroblast human cell hybrids

    International Nuclear Information System (INIS)

    Mendonca, M.S.; Redpath, J.L.; Fasching, C.L.

    1995-01-01

    The nontumorigenic HeLa x skin fibroblast hybrid cell line, CGL1, can be induced to re-express HeLa tumor-associated cell surface antigen, p75-IAP (intestinal alkaline phosphatase), with resulting neoplastic transformation, by exposure to γ radiation. This has allowed the human hybrid system to be developed into a quantitative in vitro model for radiation-induced neoplastic transformation of human cells. Recently, several γ-ray-induced IAP-expression mutants (GIMs) of the nontumorigenic HeLa x skin fibroblast hybrid CGL1 were isolated and all were tumorigenic when injected subcutaneously into nude mice. Control cell lines which were negative for p75-IAP (CONs) were also isolated from irradiated populations, and none were found to be tumorigenic. We have now begun to investigate the molecular basis of radiation-induced neoplastic transformation in this system by studying the potential genetic linkage between p75/IAP expression, tumorigenicity and damage to a putative tumor suppressor locus on fibroblast chromosome 11. Previous analysis of rare spontaneous segregants has indicated that this locus is involved in the regulation of tumorigenicity and in the expression of the HeLa tumor-associated cell surface marker intestinal alkaline phosphatase (p75-IAP) in this system. Therefore, analysis by restriction fragment length polymorphism and chromosome painting have been performed for chromosome 11, and for chromosome 13 as a control, for the p75/IAP-positive GIM and p75/IAP-negative CON cell lines. We report that in five of eight of the GIMs large-scale damage to the fibroblast chromosome 11's is evident (four GIMs have lost one complete copy of a fibroblast chromosome 11 heavily damaged). None of the CONs, however (0/5), have lost a complete copy of either fibroblast chromosome 11. No large-scale damage to the control chromosome 13's was detected in the GIMs or CONs. 49 refs., 3 figs., 2 tabs

  10. Neuropilin-2 induced by transforming growth factor-β augments migration of hepatocellular carcinoma cells

    International Nuclear Information System (INIS)

    Wittmann, Philipp; Grubinger, Markus; Gröger, Christian; Huber, Heidemarie; Sieghart, Wolfgang; Peck-Radosavljevic, Markus; Mikulits, Wolfgang

    2015-01-01

    Hepatocellular carcinoma (HCC) is the most common form of liver cancer and the third most lethal cancer worldwide. The epithelial to mesenchymal transition (EMT) describes the transformation of well-differentiated epithelial cells to a de-differentiated phenotype and plays a central role in the invasion and intrahepatic metastasis of HCC cells. Modulation of the transforming growth factor-β (TGF-β) signaling is known to induce various tumor-promoting and EMT-inducing pathways in HCC. The meta-analysis of a panel of EMT gene expression studies revealed that neuropilin 2 (NRP2) is significantly upregulated in cells that have undergone EMT induced by TGF-β. In this study we assessed the functional role of NRP2 in epithelial and mesenchymal-like HCC cells and focused on the molecular interplay between NRP2 and TGF-β/Smad signaling. NRP2 expression was analyzed in human HCC cell lines and tissue arrays comprising 133 HCC samples. Cell migration was examined by wound healing and Transwell assays in the presence and absence of siRNA against NRP2. NRP2 and TGF-β signaling were analyzed by Western blotting and confocal immunofluorescence microscopy. We show that NRP2 is particularly expressed in HCC cell lines with a dedifferentiated, mesenchymal-like phenotype. NRP2 expression is upregulated by the canonical TGF-β/Smad signaling while NRP2 expression has no impact on TGF-β signaling in HCC cells. Reduced expression of NRP2 by knock-down or inhibition of TGF-β signaling resulted in diminished cell migration independently of each other, suggesting that NRP2 fails to collaborate with TGF-β signaling in cell movement. In accordance with these data, elevated levels of NRP2 correlated with a higher tumor grade and less differentiation in a large collection of human HCC specimens. These data suggest that NRP2 associates with a less differentiated, mesenchymal-like HCC phenotype and that NRP2 plays an important role in tumor cell migration upon TGF-β-dependent HCC

  11. Agrobacterium rhizogenes-Mediated Transformation – a Non-GMO Platform For Developing Compact Ornamentals

    DEFF Research Database (Denmark)

    Lütken, Henrik Vlk; Hegelund, Josefine Nymark; Lauridsen, Uffe Bjerre

    of these compounds are potentially harmful to both the environment and human health. A new non-GMO molecular breeding strategy, as opposed to both the application of chemical growth retardants and conventional molecular breeding is Agrobacterium rhizogenes-mediated transformation. In this method, the soil borne...... for transformations, plants produced via this approach are not considered as GMOs in the European Union and Japan. We have developed an optimised Agrobacterium rhizogenes-mediated transformation platform useful for a wide range of ornamentals. Kalanchoë was the starting point and the effect of the rol-genes has now...

  12. Development of a transformation system for Chlamydia trachomatis: restoration of glycogen biosynthesis by acquisition of a plasmid shuttle vector.

    Directory of Open Access Journals (Sweden)

    Yibing Wang

    2011-09-01

    Full Text Available Chlamydia trachomatis remains one of the few major human pathogens for which there is no transformation system. C. trachomatis has a unique obligate intracellular developmental cycle. The extracellular infectious elementary body (EB is an infectious, electron-dense structure that, following host cell infection, differentiates into a non-infectious replicative form known as a reticulate body (RB. Host cells infected by C. trachomatis that are treated with penicillin are not lysed because this antibiotic prevents the maturation of RBs into EBs. Instead the RBs fail to divide although DNA replication continues. We have exploited these observations to develop a transformation protocol based on expression of β-lactamase that utilizes rescue from the penicillin-induced phenotype. We constructed a vector which carries both the chlamydial endogenous plasmid and an E.coli plasmid origin of replication so that it can shuttle between these two bacterial recipients. The vector, when introduced into C. trachomatis L2 under selection conditions, cures the endogenous chlamydial plasmid. We have shown that foreign promoters operate in vivo in C. trachomatis and that active β-lactamase and chloramphenicol acetyl transferase are expressed. To demonstrate the technology we have isolated chlamydial transformants that express the green fluorescent protein (GFP. As proof of principle, we have shown that manipulation of chlamydial biochemistry is possible by transformation of a plasmid-free C. trachomatis recipient strain. The acquisition of the plasmid restores the ability of the plasmid-free C. trachomatis to synthesise and accumulate glycogen within inclusions. These findings pave the way for a comprehensive genetic study on chlamydial gene function that has hitherto not been possible. Application of this technology avoids the use of therapeutic antibiotics and therefore the procedures do not require high level containment and will allow the analysis of genome

  13. Texture developed during deformation of Transformation Induced Plasticity (TRIP) steels

    International Nuclear Information System (INIS)

    Bhargava, M; Asim, T; Sushil, M; Shanta, C

    2015-01-01

    Automotive industry is currently focusing on using advanced high strength steels (AHSS) due to its high strength and formability for closure applications. Transformation Induced Plasticity (TRIP) steel is promising material for this application among other AHSS. The present work is focused on the microstructure development during deformation of TRIP steel sheets. To mimic complex strain path condition during forming of automotive body, Limit Dome Height (LDH) tests were conducted and samples were deformed in servo hydraulic press to find the different strain path. FEM Simulations were done to predict different strain path diagrams and compared with experimental results. There is a significant difference between experimental and simulation results as the existing material models are not applicable for TRIP steels. Micro texture studies were performed on the samples using EBSD and X-RD techniques. It was observed that austenite is transformed to martensite and texture developed during deformation had strong impact on limit strain and strain path. (paper)

  14. Texture developed during deformation of Transformation Induced Plasticity (TRIP) steels

    Science.gov (United States)

    Bhargava, M.; Shanta, C.; Asim, T.; Sushil, M.

    2015-04-01

    Automotive industry is currently focusing on using advanced high strength steels (AHSS) due to its high strength and formability for closure applications. Transformation Induced Plasticity (TRIP) steel is promising material for this application among other AHSS. The present work is focused on the microstructure development during deformation of TRIP steel sheets. To mimic complex strain path condition during forming of automotive body, Limit Dome Height (LDH) tests were conducted and samples were deformed in servo hydraulic press to find the different strain path. FEM Simulations were done to predict different strain path diagrams and compared with experimental results. There is a significant difference between experimental and simulation results as the existing material models are not applicable for TRIP steels. Micro texture studies were performed on the samples using EBSD and X-RD techniques. It was observed that austenite is transformed to martensite and texture developed during deformation had strong impact on limit strain and strain path.

  15. Development of Electrical Breakdown in Transformer Oil

    Directory of Open Access Journals (Sweden)

    Jozef Kudelcik

    2006-01-01

    Full Text Available Power transformers are key equipment for transfer and distribution of the electric power. Considering the significance of the power transformers in the electric system, their price and possible damages occurred by accidents, it is necessary to pay attention to their higher prevention. To prevent failure states of transformers, we perform different types ofmeasurements. They shall illustrate a momentary state of the measured equipment and if necessary to draw attention in advance to changes of parameters, which have specific relationship to no-failure operation of the equipment. The conditions under which breakdown of composite liquid/ solid insulation can occur, e.g. in transformer, play an important role in designing such insulation. The liquid, mainly mineral oil, generally constitutes the weakest part of insulation and a great amount of work has been devoted to the study of streamers, which appear in the gaseous phase, and most often are triggering the failure of insulation.

  16. Transforming Growth Factor-β Drives the Transendothelial Migration of Hepatocellular Carcinoma Cells

    Directory of Open Access Journals (Sweden)

    Petra Koudelkova

    2017-10-01

    Full Text Available The entry of malignant hepatocytes into blood vessels is a key step in the dissemination and metastasis of hepatocellular carcinoma (HCC. The identification of molecular mechanisms involved in the transmigration of malignant hepatocytes through the endothelial barrier is of high relevance for therapeutic intervention and metastasis prevention. In this study, we employed a model of hepatocellular transmigration that mimics vascular invasion using hepatic sinusoidal endothelial cells and malignant hepatocytes evincing a mesenchymal-like, invasive phenotype by transforming growth factor (TGF-β. Labelling of respective cell populations with various stable isotopes and subsequent mass spectrometry analyses allowed the “real-time” detection of molecular changes in both transmigrating hepatocytes and endothelial cells. Interestingly, the proteome profiling revealed 36 and 559 regulated proteins in hepatocytes and endothelial cells, respectively, indicating significant changes during active transmigration that mostly depends on cell–cell interaction rather than on TGF-β alone. Importantly, matching these in vitro findings with HCC patient data revealed a panel of common molecular alterations including peroxiredoxin-3, epoxide hydrolase, transgelin-2 and collectin 12 that are clinically relevant for the patient’s survival. We conclude that hepatocellular plasticity induced by TGF-β is crucially involved in blood vessel invasion of HCC cells.

  17. Differential display technique of RNA from tumorigenic and non-tumorigenic variants of hamster cells transformed with avian sarcoma virus

    International Nuclear Information System (INIS)

    Leksa, V.; Altaner, C.

    1997-01-01

    Differential display technique was applied to study expression of RNA in tumorigenic and non-tumorigenic cell variants of avian sarcoma virus transformed hamster cells. Methodical conditions were worked out, which allowed identifying a cDNA fragment of an unknown gene expressed in non-tumorigenic cell variant only. Its role in tumor suppression remains to be determined. (author)

  18. Study on production of useful metabolites by development of advanced cell culture techniques using radiation

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Byung Yeoup; Kim, Jinhong; Lee, Seung Sik; Bai, Hyounwoo; An, Byung Chull; Lee, Eun Mi; Lee, Jae Taek; Kim, Mi Ja

    2010-12-15

    The purpose of this project is improvement of investigation, materialization and evaluation techniques on effectiveness for functional natural compounds throughout development of tissue/cell culture techniques for mass production of useful metabolites using radiation. Research scope includes Development of a technique for radiation tissue and cell culture, Database construction for radiation response in plants and radiation effects, Construction of general-purpose national based techniques of cell culture technique using radiation. Main results are as follow: Isolation and identification of radiation induced basI gene; Determination of stresses sensitivities by transformating basI gene into arabidopsis; Isolation and identification of radiation induced chaperon proteins (PaAhpC and yPrxII) from Pseudomonas and yeast, and structural and functional analysis of the proteins; Determination of oxidative and heat resistance by transformating PaAhpC; Isolation and identification of maysin and its derivatives from centipedgrass; Investigation of enhancement technique for improving maysin and its derivatives production using radiation; Investigation of removing undesirable color in maysin and its derivatives using radiation; Determination of the effect of radiation on physiological functions of centipedgrass extracts; Identification of H{sub 2}O{sub 2} removing enzyme in radiation irradiated plant (Spinach); Determination of the effects of centipedgrass extracts on anti-obesity and anti-cancer activities.

  19. Study on production of useful metabolites by development of advanced cell culture techniques using radiation

    International Nuclear Information System (INIS)

    Chung, Byung Yeoup; Kim, Jinhong; Lee, Seung Sik; Bai, Hyounwoo; An, Byung Chull; Lee, Eun Mi; Lee, Jae Taek; Kim, Mi Ja

    2010-12-01

    The purpose of this project is improvement of investigation, materialization and evaluation techniques on effectiveness for functional natural compounds throughout development of tissue/cell culture techniques for mass production of useful metabolites using radiation. Research scope includes Development of a technique for radiation tissue and cell culture, Database construction for radiation response in plants and radiation effects, Construction of general-purpose national based techniques of cell culture technique using radiation. Main results are as follow: Isolation and identification of radiation induced basI gene; Determination of stresses sensitivities by transformating basI gene into arabidopsis; Isolation and identification of radiation induced chaperon proteins (PaAhpC and yPrxII) from Pseudomonas and yeast, and structural and functional analysis of the proteins; Determination of oxidative and heat resistance by transformating PaAhpC; Isolation and identification of maysin and its derivatives from centipedgrass; Investigation of enhancement technique for improving maysin and its derivatives production using radiation; Investigation of removing undesirable color in maysin and its derivatives using radiation; Determination of the effect of radiation on physiological functions of centipedgrass extracts; Identification of H 2 O 2 removing enzyme in radiation irradiated plant (Spinach); Determination of the effects of centipedgrass extracts on anti-obesity and anti-cancer activities

  20. Heterogeneity in both cytokine production and responsiveness of a panel of monoclonal human Epstein-Barr virus-transformed B-cell lines

    NARCIS (Netherlands)

    Jochems, G. J.; Klein, M. R.; Jordens, R.; Pascual-Salcedo, D.; van Boxtel-Oosterhof, F.; van Lier, R. A.; Zeijlemaker, W. P.

    1991-01-01

    To optimize growth and Ig production of in vitro-cultured Epstein-Barr virus (EBV)-transformed B cells, a panel of six monoclonal EBV B-cell lines was analyzed for autocrine growth factor production and responsiveness to various cytokines. Three cell lines produced Il-I and four produced Il-6,

  1. Optimizing transformations for automated, high throughput analysis of flow cytometry data.

    Science.gov (United States)

    Finak, Greg; Perez, Juan-Manuel; Weng, Andrew; Gottardo, Raphael

    2010-11-04

    In a high throughput setting, effective flow cytometry data analysis depends heavily on proper data preprocessing. While usual preprocessing steps of quality assessment, outlier removal, normalization, and gating have received considerable scrutiny from the community, the influence of data transformation on the output of high throughput analysis has been largely overlooked. Flow cytometry measurements can vary over several orders of magnitude, cell populations can have variances that depend on their mean fluorescence intensities, and may exhibit heavily-skewed distributions. Consequently, the choice of data transformation can influence the output of automated gating. An appropriate data transformation aids in data visualization and gating of cell populations across the range of data. Experience shows that the choice of transformation is data specific. Our goal here is to compare the performance of different transformations applied to flow cytometry data in the context of automated gating in a high throughput, fully automated setting. We examine the most common transformations used in flow cytometry, including the generalized hyperbolic arcsine, biexponential, linlog, and generalized Box-Cox, all within the BioConductor flowCore framework that is widely used in high throughput, automated flow cytometry data analysis. All of these transformations have adjustable parameters whose effects upon the data are non-intuitive for most users. By making some modelling assumptions about the transformed data, we develop maximum likelihood criteria to optimize parameter choice for these different transformations. We compare the performance of parameter-optimized and default-parameter (in flowCore) data transformations on real and simulated data by measuring the variation in the locations of cell populations across samples, discovered via automated gating in both the scatter and fluorescence channels. We find that parameter-optimized transformations improve visualization, reduce

  2. Optimizing transformations for automated, high throughput analysis of flow cytometry data

    Directory of Open Access Journals (Sweden)

    Weng Andrew

    2010-11-01

    Full Text Available Abstract Background In a high throughput setting, effective flow cytometry data analysis depends heavily on proper data preprocessing. While usual preprocessing steps of quality assessment, outlier removal, normalization, and gating have received considerable scrutiny from the community, the influence of data transformation on the output of high throughput analysis has been largely overlooked. Flow cytometry measurements can vary over several orders of magnitude, cell populations can have variances that depend on their mean fluorescence intensities, and may exhibit heavily-skewed distributions. Consequently, the choice of data transformation can influence the output of automated gating. An appropriate data transformation aids in data visualization and gating of cell populations across the range of data. Experience shows that the choice of transformation is data specific. Our goal here is to compare the performance of different transformations applied to flow cytometry data in the context of automated gating in a high throughput, fully automated setting. We examine the most common transformations used in flow cytometry, including the generalized hyperbolic arcsine, biexponential, linlog, and generalized Box-Cox, all within the BioConductor flowCore framework that is widely used in high throughput, automated flow cytometry data analysis. All of these transformations have adjustable parameters whose effects upon the data are non-intuitive for most users. By making some modelling assumptions about the transformed data, we develop maximum likelihood criteria to optimize parameter choice for these different transformations. Results We compare the performance of parameter-optimized and default-parameter (in flowCore data transformations on real and simulated data by measuring the variation in the locations of cell populations across samples, discovered via automated gating in both the scatter and fluorescence channels. We find that parameter

  3. Development of a stained cell nuclei counting system

    Science.gov (United States)

    Timilsina, Niranjan; Moffatt, Christopher; Okada, Kazunori

    2011-03-01

    This paper presents a novel cell counting system which exploits the Fast Radial Symmetry Transformation (FRST) algorithm [1]. The driving force behind our system is a research on neurogenesis in the intact nervous system of Manduca Sexta or the Tobacco Hornworm, which was being studied to assess the impact of age, food and environment on neurogenesis. The varying thickness of the intact nervous system in this species often yields images with inhomogeneous background and inconsistencies such as varying illumination, variable contrast, and irregular cell size. For automated counting, such inhomogeneity and inconsistencies must be addressed, which no existing work has done successfully. Thus, our goal is to devise a new cell counting algorithm for the images with non-uniform background. Our solution adapts FRST: a computer vision algorithm which is designed to detect points of interest on circular regions such as human eyes. This algorithm enhances the occurrences of the stained-cell nuclei in 2D digital images and negates the problems caused by their inhomogeneity. Besides FRST, our algorithm employs standard image processing methods, such as mathematical morphology and connected component analysis. We have evaluated the developed cell counting system with fourteen digital images of Tobacco Hornworm's nervous system collected for this study with ground-truth cell counts by biology experts. Experimental results show that our system has a minimum error of 1.41% and mean error of 16.68% which is at least forty-four percent better than the algorithm without FRST.

  4. The ThPOK transcription factor differentially affects the development and function of self-specific CD8(+) T cells and regulatory CD4(+) T cells.

    Science.gov (United States)

    Twu, Yuh-Ching; Teh, Hung-Sia

    2014-03-01

    The zinc finger transcription factor ThPOK plays a crucial role in CD4 T-cell development and CD4/CD8 lineage decision. In ThPOK-deficient mice, developing T cells expressing MHC class II-restricted T-cell receptors are redirected into the CD8 T-cell lineage. In this study, we investigated whether the ThPOK transgene affected the development and function of two additional types of T cells, namely self-specific CD8 T cells and CD4(+) FoxP3(+) T regulatory cells. Self-specific CD8 T cells are characterized by high expression of CD44, CD122, Ly6C, 1B11 and proliferation in response to either IL-2 or IL-15. The ThPOK transgene converted these self-specific CD8 T cells into CD4 T cells. The converted CD4(+) T cells are no longer self-reactive, lose the characteristics of self-specific CD8 T cells, acquire the properties of conventional CD4 T cells and survive poorly in peripheral lymphoid organs. By contrast, the ThPOK transgene promoted the development of CD4(+) FoxP3(+) regulatory T cells resulting in an increased recovery of CD4(+) FoxP3(+) regulatory T cells that expressed higher transforming growth factor-β-dependent suppressor activity. These studies indicate that the ThPOK transcription factor differentially affects the development and function of self-specific CD8 T cells and CD4(+) FoxP3(+) regulatory T cells. © 2013 John Wiley & Sons Ltd.

  5. [Sporulation or competence development? A genetic regulatory network model of cell-fate determination in Bacillus subtilis].

    Science.gov (United States)

    Lu, Zhenghui; Zhou, Yuling; Zhang, Xiaozhou; Zhang, Guimin

    2015-11-01

    Bacillus subtilis is a generally recognized as safe (GRAS) strain that has been widely used in industries including fodder, food, and biological control. In addition, B. subtilis expression system also plays a significant role in the production of industrial enzymes. However, its application is limited by its low sporulation frequency and transformation efficiency. Immense studies have been done on interpreting the molecular mechanisms of sporulation and competence development, whereas only few of them were focused on improving sporulation frequency and transformation efficiency of B. subtilis by genetic modification. The main challenge is that sporulation and competence development, as the two major developmental events in the stationary phase of B. subtilis, are regulated by the complicated intracellular genetic regulatory systems. In addition, mutual regulatory mechanisms also exist in these two developmental events. With the development of genetic and metabolic engineering, constructing genetic regulatory networks is currently one of the most attractive research fields, together with the genetic information of cell growth, metabolism, and development, to guide the industrial application. In this review, the mechanisms of sporulation and competence development of B. subtilis, their interactions, and the genetic regulation of cell growth were interpreted. In addition, the roles of these regulatory networks in guiding basic and applied research of B. subtilis and its related species were discussed.

  6. Antioxidant ability and radiosensitivity in malignant transformed human bronchial epithelial cell line BEP2D induced by α-particle irradiation

    International Nuclear Information System (INIS)

    Gou Qiao; Zhang Wei; Wang Chunyan; Su Xu

    2011-01-01

    Objective: To investigate the antioxidant ability and radiosensitivity in the malignant transformed human bronchial epithelial cell line BEP2D induced by α-particle exposure. Methods: Glutathione Peroxidase (GPX), Catalase (CAT) and Glutathione (GSH) assay kits were employed to detect GPX and CAT enzyme abilities and the levels of GSH in BEP2D, RH21 (passage 21 of α-particle-irradiated BEP2D cells), and BERP35T-1 cells (derived from nude mice bearing malignant transformed cells generated from cells of passage 35 of α-particle-irradiated BEP2D cells). MTT assay were used to test the growth rate of BEP2D, RH21 and BERP35T-1 cells treated with 0, 30, 60, 90, 120, and 150 μmoL/L H 2 O 2 . Colony-forming test and MTT assay were used to examine the cell survival fraction and the growth rate of BEP2D, RH21 and BERP35T-1 cells exposed to 0, 2, 4, and 8 Gy of γ-rays,respectively. Results: GPX and CAT enzyme activities in RH21 and BERP35T-1 cells were obviously lower than in BEP2D (t=5.75-67.92, P<0.05). CAT enzyme activity in BERP35T-1 was lower than that in RH21 cells (t=22.25, P<0.01). Compared to BEP2D cells, decreased level of GSH was detected in BERP35T-1 cells (t=7.76, P<0.05), but there was no change in RH21. After treatment with 30, 60, 90, 120, and 150 μmol/L H 2 O 2 , the growth rates of BEP2D were all higher than those of BERP35T-1 cells (t=10.37-58.36, P<0.01). Meanwhile,the growth rates of BEP2D were all higher than those of RH21 cells after treatment with 60, 90, 120, and 150 μ mol/L H 2 O 2 (t =29.90-84.68, P<0.01). In addition,compared to BEP2D cells,decreased cell survival fraction and growth rate of BERP35T-1 cells were observed after irradiation with 2, 4, and 8 Gy of y-rays (t=5.87-34.17, P<0.05). The cell survival fraction and growth rate of RH21 were all lower than those of BEP2D cells at 4 and 8 Gy post-irradiation (t=6.33- 45.00, P<0.05). Conclusion: The function of antioxidant system decreased in the α-particle-induced transformed cells

  7. 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)

    Liu, Yi; Luo, Fei; Xu, Yuan; Wang, Bairu; Zhao, Yue; Xu, Wenchao; Shi, Le; Lu, Xiaolin; Liu, Qizhan

    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

  8. Dissociation of DNA damage and mitochondrial injury caused by hydrogen peroxide in SV-40 transformed lung epithelial cells

    Directory of Open Access Journals (Sweden)

    Adcock Ian M

    2002-11-01

    Full Text Available Abstract Background Since lung epithelial cells are constantly being exposed to reactive oxygen intermediates (ROIs, the alveolar surface is a major site of oxidative stress, and each cell type may respond differently to oxidative stress. We compared the extent of oxidative DNA damage with that of mitochondrial injury in lung epithelial cells at the single cell level. Result DNA damage and mitochondrial injury were measured after oxidative stress in the SV-40 transformed lung epithelial cell line challenged with hydrogen peroxide (H2O2. Single cell analysis of DNA damage was determined by assessing the number of 8-oxo-2-deoxyguanosine (8-oxo-dG positive cells, a marker of DNA modification, and the length of a comet tail. Mitochondrial membrane potential, ΔΨm, was determined using JC-1. A 1 h pulse of H2O2 induced small amounts of apoptosis (3%. 8-oxo-dG-positive cells and the length of the comet tail increased within 1 h of exposure to H2O2. The number of cells with reduced ΔΨm increased after the addition of H2O2 in a concentration-dependent manner. In spite of a continual loss of ΔΨm, DNA fragmentation was reduced 2 h after exposure to H2O2. Conclusion The data suggest that SV-40 transformed lung epithelial cells are resistant to oxidative stress, showing that DNA damage can be dissociated from mitochondrial injury.

  9. Perspective loads of transformer substations at development of urban power supply systems

    Directory of Open Access Journals (Sweden)

    Svetlana Guseva

    2012-06-01

    Full Text Available In work the system approach to formation of the urban power supply system is given. The hierarchical structure of the construction, voltage levels and load densities is considered. The mathematical and geometrical modeling of service areas for transformer substations of diff erent voltage is fulfi lled. Determination of perspective loads of transformer substations is given. The method of graphic placement of transformer substations in the city territory for new substations at existing structure of networks is off ered. The calculation program Microsoft EXCEL and the graphic program AutoCad are used for realization of method. The method allows fi nding a rational decision for the development of urban power supply system on the beginning design stages in conditions of the information uncertainty.

  10. MicroRNA-200b Suppresses Arsenic-transformed Cell Migration by Targeting Protein Kinase Cα and Wnt5b-Protein Kinase Cα Positive Feedback Loop and Inhibiting Rac1 Activation*

    Science.gov (United States)

    Wang, Zhishan; Humphries, Brock; Xiao, Hua; Jiang, Yiguo; Yang, Chengfeng

    2014-01-01

    MicroRNA-200b (miR-200b) is a member of miR-200 family that has been found to inhibit cell migration and cancer metastasis; however, the underlying mechanism is not well understood. We previously reported that miR-200 expression is depleted in arsenic-transformed human bronchial epithelial cells with highly migratory and invasive characteristics, whereas stably re-expressing miR-200b strongly suppresses arsenic-transformed cell migration. This study was performed to investigate how miR-200b inhibits arsenic-transformed cell migration. We found that protein kinase Cα (PKCα) is significantly up-regulated in arsenic-transformed cells. Combining bioinformatics analysis with PKCα 3′-untranslated region vector luciferase reporter assays, we showed that PKCα is a direct target of miR-200b. Inhibiting PKCα activity or knocking down PKCα expression drastically reduced cell migration, phenocoping the inhibitory effect of overexpressing miR-200b. In contrast, forced expression of PKCα in miR-200b overexpressing cells impaired the inhibitory effect of miR-200b on cell migration. In addition, we also found a positive feedback loop between Wnt5b and PKCα in arsenic-transformed cells. Knocking down Wnt5b expression reduced phospho-PKC levels and cell migration; and knocking down PKCα expression decreased Wnt5b level and cell migration. Moreover, forced expression of PKCα increased Wnt5b and phospho-PKC levels and cell migration. Further mechanistic studies revealed that Rac1 is highly activated in arsenic-transformed cells and stably expressing miR-200b abolishes Rac1 activation changing actin cytoskeleton organization. Manipulating PKCα or Wnt5b expression levels significantly altered the level of active Rac1. Together, these findings indicate that miR-200b suppresses arsenic-transformed cell migration by targeting PKCα and Wnt5b-PKCα positive feedback loop and subsequently inhibiting Rac1 activation. PMID:24841200

  11. MicroRNA-200b suppresses arsenic-transformed cell migration by targeting protein kinase Cα and Wnt5b-protein kinase Cα positive feedback loop and inhibiting Rac1 activation.

    Science.gov (United States)

    Wang, Zhishan; Humphries, Brock; Xiao, Hua; Jiang, Yiguo; Yang, Chengfeng

    2014-06-27

    MicroRNA-200b (miR-200b) is a member of miR-200 family that has been found to inhibit cell migration and cancer metastasis; however, the underlying mechanism is not well understood. We previously reported that miR-200 expression is depleted in arsenic-transformed human bronchial epithelial cells with highly migratory and invasive characteristics, whereas stably re-expressing miR-200b strongly suppresses arsenic-transformed cell migration. This study was performed to investigate how miR-200b inhibits arsenic-transformed cell migration. We found that protein kinase Cα (PKCα) is significantly up-regulated in arsenic-transformed cells. Combining bioinformatics analysis with PKCα 3'-untranslated region vector luciferase reporter assays, we showed that PKCα is a direct target of miR-200b. Inhibiting PKCα activity or knocking down PKCα expression drastically reduced cell migration, phenocoping the inhibitory effect of overexpressing miR-200b. In contrast, forced expression of PKCα in miR-200b overexpressing cells impaired the inhibitory effect of miR-200b on cell migration. In addition, we also found a positive feedback loop between Wnt5b and PKCα in arsenic-transformed cells. Knocking down Wnt5b expression reduced phospho-PKC levels and cell migration; and knocking down PKCα expression decreased Wnt5b level and cell migration. Moreover, forced expression of PKCα increased Wnt5b and phospho-PKC levels and cell migration. Further mechanistic studies revealed that Rac1 is highly activated in arsenic-transformed cells and stably expressing miR-200b abolishes Rac1 activation changing actin cytoskeleton organization. Manipulating PKCα or Wnt5b expression levels significantly altered the level of active Rac1. Together, these findings indicate that miR-200b suppresses arsenic-transformed cell migration by targeting PKCα and Wnt5b-PKCα positive feedback loop and subsequently inhibiting Rac1 activation. © 2014 by The American Society for Biochemistry and Molecular

  12. Transformation of fruit trees. Useful breeding tool or continued future prospect?

    Science.gov (United States)

    Petri, César; Burgos, Lorenzo

    2005-02-01

    Regeneration and transformation systems using mature plant material of woody fruit species have to be achieved as a necessary requirement for the introduction of useful genes into specific cultivars and the rapid evaluation of resulting horticultural traits. Although the commercial production of transgenic annual crops is a reality, commercial genetically-engineered fruit trees are still far from common. In most woody fruit species, transformation and regeneration of commercial cultivars are not routine, generally being limited to a few genotypes or to seedlings. The future of genetic transformation as a tool for the breeding of fruit trees requires the development of genotype-independent procedures, based on the transformation of meristematic cells with high regeneration potential and/or the use of regeneration-promoting genes. The public concern with the introduction of antibiotic resistance into food and the restrictions due to new European laws that do not allow deliberate release of plants transformed with antibiotic-resistance genes highlight the development of methods that avoid the use of antibiotic-dependent selection or allow elimination of marker genesfrom the transformed plant as a research priority in coming years.

  13. Agrobacterium-mediated transformation of lipomyces

    Science.gov (United States)

    Dai, Ziyu; Magnuson, Jon K.; Deng, Shuang; Bruno, Kenneth S.; Culley, David E.

    2018-03-13

    This disclosure provides Agrobacterium-mediated transformation methods for the oil-producing (oleaginous) yeast Lipomyces sp., as well as yeast produced by the method. Such methods utilize Agrobacterium sp. cells that have a T-DNA binary plasmid, wherein the T-DNA binary plasmid comprises a first nucleic acid molecule encoding a first protein and a second nucleic acid molecule encoding a selective marker that permits growth of transformed Lipomyces sp. cells in selective culture media comprising an antibiotic.

  14. Transformation of intimacy and its impact in developing countries.

    Science.gov (United States)

    Muniruzzaman, M D

    2017-12-01

    Nowadays intimacy or intimate relationship is very familiar and widely used term all over the world. The term 'Intimacy' generally denotes a close interpersonal relationship or feeling of being in a close personal association and belonging together from both physical and mental point of view. It also denotes very close and effective connection with one another which may exist for whole life or may not. This article has been prepared on the basis of secondary sources and it tries to explore how this intimacy or intimate relationship has been gradually transforming from pre-modern society to modern society and from modern society to post-modern society for over the eras. This article also tries to explore the impact of transformed intimacy or intimate relationship, especially in the developing countries, like Bangladesh. Intimate relationship plays very significant role in the overall life style of any human being. This relationship includes feelings of liking, romance, sexuality or sexual relationship, emotional or personal support between mates. But the role of sexuality or sexual relationship is gradually increasing in intimacy, not only in the western countries but also in the developing countries. Nowadays people are involved with many kinds of premarital and extramarital relationships and they try to avoid the risk of reproduction. This tendency creates many problems in the developing countries, as most of the people of such developing countries are poor and illiterate. They are not aware about the dangerous impact of unsafe physical or sexual relationship. So the people of developing countries like Bangladesh are very vulnerable in the aspect of erosion of values and spreading different types of sexually transmitted diseases.

  15. Development of iPS (induced pluripotent stem cells) using natural product from extract of fish oocyte to provide stem cell for regenerative therapy

    Science.gov (United States)

    Meilany, Sofy; Firdausiyah, Qonitha S.; Naroeni, Aroem

    2017-02-01

    In this study, we developed a method to induce pluripotency of adult cells (fibroblast) into stem cells using a natural product, extract of fish oocyte, by comparing the extract concentration, 1 mg/ml and