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Sample records for cell mediated cytotoxicity

  1. Natural killer cell mediated cytotoxic responses in the Tasmanian devil.

    Science.gov (United States)

    Brown, Gabriella K; Kreiss, Alexandre; Lyons, A Bruce; Woods, Gregory M

    2011-01-01

    The Tasmanian devil (Sarcophilus harrisii), the world's largest marsupial carnivore, is under threat of extinction following the emergence of an infectious cancer. Devil facial tumour disease (DFTD) is spread between Tasmanian devils during biting. The disease is consistently fatal and devils succumb without developing a protective immune response. The aim of this study was to determine if Tasmanian devils were capable of forming cytotoxic antitumour responses and develop antibodies against DFTD cells and foreign tumour cells. The two Tasmanian devils immunised with irradiated DFTD cells did not form cytotoxic or humoral responses against DFTD cells, even after multiple immunisations. However, following immunisation with xenogenic K562 cells, devils did produce cytotoxic responses and antibodies against this foreign tumour cell line. The cytotoxicity appeared to occur through the activity of natural killer (NK) cells in an antibody dependent manner. Classical NK cell responses, such as innate killing of DFTD and foreign cancer cells, were not observed. Cells with an NK-like phenotype comprised approximately 4 percent of peripheral blood mononuclear cells. The results of this study suggest that Tasmanian devils have NK cells with functional cytotoxic pathways. Although devil NK cells do not directly recognise DFTD cancer cells, the development of antibody dependent cell-mediated cytotoxicity presents a potential pathway to induce cytotoxic responses against the disease. These findings have positive implications for future DFTD vaccine research. PMID:21957452

  2. Measurement of cell mediated cytotoxicity by post-labeling surviving target cells

    International Nuclear Information System (INIS)

    The 51Cr release assay (CRA) is the commonly accepted technique for measurement of cell mediated cytotoxicity. This assay shows some disadvantages when mononucleated cells of human peripheral blood (MNC) are used as effector and target cells. The uptake of 51Cr by PHA stimulated lymphocytes is low compared to the spontaneous release. In an attempt to develop a cytotoxicity assay suitable for human lymphocytes we used 14C-TdR to label target cells surviving after contact with effector cells. Cytotoxic lymphocytes were generated by incubation of MNC with irradiated allogeneic MNC for 6 days. On day 6 the effector cells are irradiated and cocultured with PHA stimulated target cells. Twenty-four hours later 14C-TdR is added. After an additional 24 h the cultures are harvested and 14C-TdR taken up by target cells is measured. It is shown that the effector cells are still cytotoxic after irradiation. These cells do not take up 14C-TdR. Cell-free supernatants do not influence the uptake of 14C-TdR by target cells. The results obtained with this assay correlate very well those obtained by the CRA, if the spontaneous release does not exceed 30%. (author)

  3. Mannose 6-, fructose 1-, and fructose 6-phosphates inhibit human natural cell-mediated cytotoxicity.

    OpenAIRE

    Forbes, J T; Bretthauer, R. K.; Oeltmann, T N

    1981-01-01

    In vitro human natural cell-mediated cytotoxicity (NCMC) to K-562, Molt-4, and F-265 cells is inhibited in a dose-dependent manner by mannose 6-phosphate, fructose 1-phosphate and fructose 6-phosphate. This inhibition is not observed with mannose, glucose, fucose, glucose 6-phosphate, mannose 1-phosphate, galactose 1-phosphate, or galactose 6-phosphate. Preincubation of the effector cells, obtained from fresh whole blood, with mannose-6-phosphate, fructose-1-phosphate, or fructose-6-phosphate...

  4. Natural Killer Cell Mediated Cytotoxic Responses in the Tasmanian Devil

    OpenAIRE

    Brown, Gabriella K.; Kreiss, Alexandre; Lyons, A. Bruce; Woods, Gregory M.

    2011-01-01

    The Tasmanian devil (Sarcophilus harrisii), the world's largest marsupial carnivore, is under threat of extinction following the emergence of an infectious cancer. Devil facial tumour disease (DFTD) is spread between Tasmanian devils during biting. The disease is consistently fatal and devils succumb without developing a protective immune response. The aim of this study was to determine if Tasmanian devils were capable of forming cytotoxic antitumour responses and develop antibodies against D...

  5. Fasting-Mimicking Diet Reduces HO-1 to Promote T Cell-Mediated Tumor Cytotoxicity.

    Science.gov (United States)

    Di Biase, Stefano; Lee, Changhan; Brandhorst, Sebastian; Manes, Brianna; Buono, Roberta; Cheng, Chia-Wei; Cacciottolo, Mafalda; Martin-Montalvo, Alejandro; de Cabo, Rafael; Wei, Min; Morgan, Todd E; Longo, Valter D

    2016-07-11

    Immune-based interventions are promising strategies to achieve long-term cancer-free survival. Fasting was previously shown to differentially sensitize tumors to chemotherapy while protecting normal cells, including hematopoietic stem and immune cells, from its toxic side effects. Here, we show that the combination of chemotherapy and a fasting-mimicking diet (FMD) increases the levels of bone marrow common lymphoid progenitor cells and cytotoxic CD8(+) tumor-infiltrating lymphocytes (TILs), leading to a major delay in breast cancer and melanoma progression. In breast tumors, this effect is partially mediated by the downregulation of the stress-responsive enzyme heme oxygenase-1 (HO-1). These data indicate that FMD cycles combined with chemotherapy can enhance T cell-dependent targeted killing of cancer cells both by stimulating the hematopoietic system and by enhancing CD8(+)-dependent tumor cytotoxicity. PMID:27411588

  6. CDK8-Mediated STAT1-S727 Phosphorylation Restrains NK Cell Cytotoxicity and Tumor Surveillance

    Science.gov (United States)

    Putz, Eva Maria; Gotthardt, Dagmar; Hoermann, Gregor; Csiszar, Agnes; Wirth, Silvia; Berger, Angelika; Straka, Elisabeth; Rigler, Doris; Wallner, Barbara; Jamieson, Amanda M.; Pickl, Winfried F.; Zebedin-Brandl, Eva Maria; Müller, Mathias; Decker, Thomas; Sexl, Veronika

    2013-01-01

    Summary The transcription factor STAT1 is important in natural killer (NK) cells, which provide immediate defense against tumor and virally infected cells. We show that mutation of a single phosphorylation site (Stat1-S727A) enhances NK cell cytotoxicity against a range of tumor cells, accompanied by increased expression of perforin and granzyme B. Stat1-S727A mice display significantly delayed disease onset in NK cell-surveilled tumor models including melanoma, leukemia, and metastasizing breast cancer. Constitutive phosphorylation of S727 depends on cyclin-dependent kinase 8 (CDK8). Inhibition of CDK8-mediated STAT1-S727 phosphorylation may thus represent a therapeutic strategy for stimulating NK cell-mediated tumor surveillance. PMID:23933255

  7. CDK8-Mediated STAT1-S727 Phosphorylation Restrains NK Cell Cytotoxicity and Tumor Surveillance

    Directory of Open Access Journals (Sweden)

    Eva Maria Putz

    2013-08-01

    Full Text Available The transcription factor STAT1 is important in natural killer (NK cells, which provide immediate defense against tumor and virally infected cells. We show that mutation of a single phosphorylation site (Stat1-S727A enhances NK cell cytotoxicity against a range of tumor cells, accompanied by increased expression of perforin and granzyme B. Stat1-S727A mice display significantly delayed disease onset in NK cell-surveilled tumor models including melanoma, leukemia, and metastasizing breast cancer. Constitutive phosphorylation of S727 depends on cyclin-dependent kinase 8 (CDK8. Inhibition of CDK8-mediated STAT1-S727 phosphorylation may thus represent a therapeutic strategy for stimulating NK cell-mediated tumor surveillance.

  8. Mechanism of arctigenin-mediated specific cytotoxicity against human lung adenocarcinoma cell lines.

    Science.gov (United States)

    Susanti, Siti; Iwasaki, Hironori; Inafuku, Masashi; Taira, Naoyuki; Oku, Hirosuke

    2013-12-15

    The lignan arctigenin (ARG) from the herb Arctium lappa L. possesses anti-cancer activity, however the mechanism of action of ARG has been found to vary among tissues and types of cancer cells. The current study aims to gain insight into the ARG mediated mechanism of action involved in inhibiting proliferation and inducing apoptosis in lung adenocarcinoma cells. This study also delineates the cancer cell specificity of ARG by comparison with its effects on various normal cell lines. ARG selectively arrested the proliferation of cancer cells at the G0/G1 phase through the down-regulation of NPAT protein expression. This down-regulation occurred via the suppression of either cyclin E/CDK2 or cyclin H/CDK7, while apoptosis was induced through the modulation of the Akt-1-related signaling pathway. Furthermore, a GSH synthase inhibitor specifically enhanced the cytotoxicity of ARG against cancer cells, suggesting that the intracellular GSH content was another factor influencing the susceptibility of cancer cells to ARG. These findings suggest that specific cytotoxicity of ARG against lung cancer cells was explained by its selective modulation of the expression of NPAT, which is involved in histone biosynthesis. The cytotoxicity of ARG appeared to be dependent on the intracellular GSH level. PMID:24021157

  9. Cytotoxicity of some oxysterols on human vascular smooth muscle cells was mediated by apoptosis.

    Science.gov (United States)

    Miyashita, Y; Shirai, K; Ito, Y; Watanabe, J; Urano, Y; Murano, T; Tomioka, H

    1997-01-01

    A decrease in smooth muscle cells is observed in advanced atherosclerotic lesion. To understand this mechanism, we selected oxysterols as candidates for toxic lipid, and examined their cytotoxicity on human cultured vascular smooth muscle cells, together with the manner of cell death. In the presence of 7-ketocholesterol or 7 beta-hydroxycholesterol (50 mumol/L), the percentage of detached cells increased significantly with dose dependency, and an increase in detached cell number and DNA nick detected by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling study (TUNEL) preceded an increase in lactate dehydrogenase released into the medium. DNA extracted from smooth muscle cells incubated with 7-ketocholesterol or 7 beta-hydroxycholesterol showed a laddering pattern on agarose electrophoresis. In the presence of 7-ketocholesterol or 7 beta-hydroxycholesterol, fragmented DNA quantified by the quantitative sandwich enzyme immunoassay was significantly increased. From these results, it is proposed that 7-ketocholesterol and 7 beta-hydroxycholesterol are toxic to smooth muscle cells, and that this cytotoxicity is mediated by apoptosis. PMID:9638517

  10. HLA-G inhibits xenogenetic cytotoxicity mediated by human NK cells and T lymphocytes against PECs

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    In order to investigate whether the non-classi-cal HLA-G classⅠmolecule protects the porcine endothelial cells (PECs) from the lysis mediated by human immune cells in pig to human discordant xenotransplantation, we have cloned HLA-G cDNA from a human placenta by RT-PCR. Mammalian expression vector, pEFG-neo, was constructed by insertion of HLA-G cDNA in pEF-neo. We obtained efficiently expressed PECs by stable transfection. Cytotoxicity assay showed that overexpression of HLA-G on PECs was sufficient to inhibit human NK-92 cell lysis. The level of lysis was equal to or less than that of the lysis of human umbilical vein endothelial cells mediated by human NK-92 cells. It also indicated that HLA-G inhibited the lysis of PECs mediated by xeno-antigen specific T lymphocytes. The reduction of lysis ranged between 59.1% and 88.9%. These findings suggest that the transgenic approach to overexpress HLA-G is believed to be a new immunotherapy in overcoming the immune rejections in xenotransplantion, including delayed xenograft rejection and cell-mediated rejection.

  11. Enhancement of antibody-dependent cell mediated cytotoxicity: a new era in cancer treatment

    Directory of Open Access Journals (Sweden)

    Rajasekaran N

    2015-05-01

    Full Text Available Narendiran Rajasekaran,1,* Cariad Chester,1,* Atsushi Yonezawa,1,2 Xing Zhao,1,3 Holbrook E Kohrt1 1Division of Oncology, Stanford School of Medicine, Stanford University, Stanford, CA, USA; 2Department of Clinical Pharmacology and Therapeutics, Kyoto University Hospital, Kyoto, Japan; 3Tissue Engineering and Stem Cells Research Center, Department of Immunology, Guiyang Medical University, Guiyang, Guizhou Province, People's Republic of China *These authors contributed equally to this work Abstract: The therapeutic efficacy of some anti-tumor monoclonal antibodies (mAbs depends on the capacity of the mAb to recognize the tumor-associated antigen and induce cytotoxicity via a network of immune effector cells. This process of antibody-dependent cell-mediated cytotoxicity (ADCC against tumor cells is triggered by the interaction of the fragment crystallizable (Fc portion of the mAb with the Fc receptors on effector cells like natural killer cells, macrophages, γδ T cells, and dendritic cells. By augmenting ADCC, the antitumor activity of mAbs can be significantly increased. Currently, identifying and developing therapeutic agents that enhance ADCC is a growing area of research. Combining existing tumor-targeting mAbs and ADCC-promoting agents that stimulate effector cells will translate to greater clinical responses. In this review, we discuss strategies for enhancing ADCC and emphasize the potential of combination treatments that include US Food and Drug Administration-approved mAbs and immunostimulatory therapeutics. Keywords: ADCC, NK cell, reovirus, TLR, CD137

  12. TCR down-regulation boosts T-cell-mediated cytotoxicity and protection against poxvirus infections

    DEFF Research Database (Denmark)

    Hansen, Ann K; Regner, Matthias; Bonefeld, Charlotte M;

    2011-01-01

    Cytotoxic T (Tc) cells play a key role in the defense against virus infections. Tc cells recognize infected cells via the T-cell receptor (TCR) and subsequently kill the target cells by one or more cytotoxic mechanisms. Induction of the cytotoxic mechanisms is finely tuned by the activation signals...... from the TCR. To determine whether TCR down-regulation affects the cytotoxicity of Tc cells, we studied TCR down-regulation-deficient CD3¿LLAA mice. We found that Tc cells from CD3¿LLAA mice have reduced cytotoxicity due to a specific deficiency in exocytosis of lytic granules. To determine whether....... Finally, we found that TCR signaling in CD3¿LLAA Tc cells caused highly increased tyrosine phosphorylation and activation of the c-Cbl ubiquitin ligase, and that the impaired exocytosis of lytic granules could be rescued by the knockdown of c-Cbl. Thus, our work demonstrates that TCR down-regulation...

  13. Effector cell mediated cytotoxicity measured by intracellular Granzyme B release in HIV infected subjects

    Directory of Open Access Journals (Sweden)

    Mahajan Supriya D.

    2003-01-01

    Full Text Available CD8+ cytotoxic T lymphocyte (CTL activity is currently believed to be one of the key immunologic mechanisms responsible for the prevention or attenuation of HIV-1 infection. The induction of CD8+ T cell activation may also result in the production of soluble or non-classical lytic factors that are associated with protection from infection or slower disease progression. Traditionally, CD8+ CTL responses have been measured by the classic chromium release assay, monitoring the ability of T cells (Effector cells to lyse radiolabelled HLA – matched “target cells” that express the appropriate antigen-MHC complex. This method is not only labor intensive, semi quantitative assay at best, but also needs fresh, non-cryopreserved cells. Recently, cytokine specific ELISPOT assays or tetrameric MHC-I/ peptide complexes have utilized to directly quantitate circulating CD8+ effector cells, and these assays are more sensitive, quantitative and reproducible than the traditional CTL lysis assay and can also be performed on cryopreserved cells. Although these are reproducible assays for the assessment of soluble antiviral activity secreted by activated T cell populations they can be extremely expensive to perform. We have used FACS Analysis to measure Granzyme B release as a function of cell mediated cytotoxicity. This method helps quantitate the CTL activity and also identifies the phenotype of the cells elucidating this immune response. The method described not only monitors immunological response but also is also simple to perform, precise and extremely time efficient and is ideal for screening a large number of samples.

  14. CHARACTERISTICS OF SIGNALING PATHWAYS MEDIATING A CYTOTOXIC EFFECT OF DENDRITIC CELLS UPON ACTIVATED Т LYMPHOCYTES AND NK CELLS

    Directory of Open Access Journals (Sweden)

    T. V. Tyrinova

    2014-07-01

    Full Text Available Abstract. Cytotoxic/pro-apoptogenic effects of IFNα-induced dendritic cells (IFN-DCs directed against Т-lymphocytes and NK cells were investigated in healthy donors. Using an allogenic MLC system, it was revealed that IFN-DCs induce apoptosis of both activated CD4+ and CD8+ T-lymphocytes, and NK cells. Apoptosis of CD4+ and CD8+ T-lymphocytes induced by their interaction with IFN-DCs was mediated by various signaling pathways. In particular, activated CD4+Т-lymphocytes were most sensitive to TRAIL- и Fas/ FasL-transduction pathways, whereas activated CD8+ T-lymphocytes were induced to apoptosis via TNFα-mediated pathway. PD-1/B7-H1-signaling pathway also played a distinct role in cytotoxic activity of IFNDCs towards both types of T lymphocytes and activated NK cells. The pro-apoptogenic/cytotoxic activity of IFN-DC against activated lymphocytes may be regarded as a mechanism of a feedback regulation aimed at restriction of immune response and maintenance of immune homeostasis. Moreover, upregulation of proapoptogenic molecules on DCs under pathological conditions may lead to suppression of antigen-specific response, thus contributing to the disease progression.

  15. Separation of effector cells mediating antibody-dependent cellular cytotoxicity (ADC) to erythrocyte targets from those mediating ADC to tumor targets.

    Science.gov (United States)

    Pollack, S B; Nelson, K; Grausz, J D

    1976-04-01

    Murine spleen cells mediate antibody-dependent cellular cytotoxicity (ADC) both to erythrocyte targets in a 51Cr release assay and to syngeneic tumor targets in a microcytotoxicity assay. The effector cells active in the two ADC assays can be separated by passage of the spleen cells through columns of Sephadex G-10 at 37 degrees C. Cells mediating ADC to sarcoma cells did not adhere to the G-10 and were recovered in the column effluent. These nonadherent cells were not cytotoxic to antibody-coated chicken red blood cells. Spleen cells which mediated ADC in a 51Cr release assay to the red cell targets adhered to G-10. Adherent effector cells could subsequently be recovered from the columns by elution with 5 X 10(-4) M EDTA. PMID:815438

  16. Melanoma cell lysosome secretory burst neutralizes the CTL-mediated cytotoxicity at the lytic synapse

    Science.gov (United States)

    Khazen, Roxana; Müller, Sabina; Gaudenzio, Nicolas; Espinosa, Eric; Puissegur, Marie-Pierre; Valitutti, Salvatore

    2016-01-01

    Human melanoma cells express various tumour antigens that are recognized by CD8+ cytotoxic T lymphocytes (CTLs) and elicit tumour-specific responses in vivo. However, natural and therapeutically enhanced CTL responses in melanoma patients are of limited efficacy. The mechanisms underlying CTL effector phase failure when facing melanomas are still largely elusive. Here we show that, on conjugation with CTL, human melanoma cells undergo an active late endosome/lysosome trafficking, which is intensified at the lytic synapse and is paralleled by cathepsin-mediated perforin degradation and deficient granzyme B penetration. Abortion of SNAP-23-dependent lysosomal trafficking, pH perturbation or impairment of lysosomal proteolytic activity restores susceptibility to CTL attack. Inside the arsenal of melanoma cell strategies to escape immune surveillance, we identify a self-defence mechanism based on exacerbated lysosome secretion and perforin degradation at the lytic synapse. Interfering with this synaptic self-defence mechanism might be useful in potentiating CTL-mediated therapies in melanoma patients. PMID:26940455

  17. IFN-α primes T- and NK-cells for IL-15-mediated signaling and cytotoxicity

    DEFF Research Database (Denmark)

    Hansen, Mikkel L; Woetmann, Anders; Krejsgaard, Thorbjørn;

    2011-01-01

    -α fosters the production of IL-15, which plays a pivotal role in the development, survival and function of NK cells and recruitment and activation of T cells. Since these two cytokines exert overlapping functions during infections, this investigation was undertaken to study the priming effect of IFN-α on...... the effect of IL-15 on human T and NK cells. We show that IFN-α induces an increased expression of IL-15Rα in human activated peripheral T cells, and in CD8(+) and CD4(+) T-cell lines. Functionally, the IFN-α-enhanced IL-15Rα expression resulted in an enhanced IL-15-mediated phosphorylation of STAT5...... and STAT3 followed by a further increase in IL-15Rα expression. Moreover, IFN-α significantly increased the IL-15-induced cytotoxic activity of freshly isolated T and NK cells. Taken together, our data show that IFN-α boosts signaling and functional effects of IL-15, at least in part by fostering the...

  18. Development of a mechanistically-based genetically engineered PC12 cell system to detect p53-mediated cytotoxicity.

    Science.gov (United States)

    van Vliet, Erwin; Eskes, Chantra; Stingele, Silvia; Gartlon, Joanne; Price, Anna; Farina, Massimo; Ponti, Jessica; Hartung, Thomas; Sabbioni, Enrico; Coecke, Sandra

    2007-06-01

    The human wild type p53 gene, key for apoptosis, was introduced into the pheochromocytoma (PC12) cell line, to create a mechanistically-based in vitro test model for the detection of p53-mediated toxicity. Expression of the wt p53 gene was regulated by a system, which allowed or blocked expression p53 by absence or presence of tetracycline in the culture media. Western blot analyses confirmed an inducible and tetracycline-dependent expression of the wt p53 protein. Functionality of the p53 protein was verified by camptothecin treatment, known to induce p53-dependent apoptosis. Results showed that p53-expressing cells were significantly more sensitive to camptothecin induced cytotoxicity compared to non-expressing cells, and presented a significantly higher incidence of apoptosis. A screening study on 31 metal compounds, showed that the classified human carcinogens (NaAsO2, CdSO4 .8H2O, Na2CrO4 .4H2O, MnCl2, (NH4)2PtCl6) significantly increased cytotoxicity in p53-expressing cells compared to non-expressing cells, suggesting that their cytotoxicity was p53-mediated. Finally, acute and subchronic treatment with methyl mercury showed no significant differences in cytotoxicity and the percentage of apoptosis or necrosis between p53-expressing and non-expressing differentiated cells, suggesting that methyl mercury cytotoxicity was p53-independent. PMID:17258428

  19. Integrin Receptors on Tumor Cells Facilitate NK cell-mediated Antibody-dependent Cytotoxicity

    OpenAIRE

    Anikeeva, Nadia; Steblyanko, Maria; Fayngerts, Svetlana; Kopylova, Natalya; Marshall, Deborah J.; Powers, Gordon D.; Sato, Takami; Campbell, Kerry S.; Sykulev, Yuri

    2014-01-01

    NK cells that mediate ADCC play an important role in tumor-specific immunity. We have examined factors limiting specific lysis of tumor cells by CD16.NK-92 cells induced by CNTO 95LF antibodies recognizing αV integrins that are overexpressed on many tumor cells. Although all tested tumor cells were killed by CD16.NK-92 effectors in the presence of the antibodies, the killing of target cells with a low level of ICAM-1 expression revealed a dramatic decrease in their specific lysis at high anti...

  20. Tc17 cells are capable of mediating immunity to vaccinia virus by acquisition of a cytotoxic phenotype

    OpenAIRE

    Yeh, Norman; Glosson, Nicole L.; Wang, Nan; Guindon, Lynette; McKinley, Carl; Hamada, Hiromasa; Li, Qingsheng; Dutton, Richard W.; Shrikant, Protul; Zhou, Baohua; Brutkiewicz, Randy R.; Blum, Janice S.; Kaplan, Mark H.

    2010-01-01

    CD8 T cells can acquire cytokine-secreting phenotypes paralleling cytokine production from Th cells. IL-17-secreting CD8 T cells, termed Tc17 cells, have been shown to promote inflammation and mediate immunity to influenza. However, most reports have observed a lack of cytotoxic activity by Tc17 cells. In this report, we explored the anti-viral activity of Tc17 cells using a vaccinia virus infection (VV) model. Tc17 cells expanded during VV infection, and TCR transgenic Tc17 cells were capabl...

  1. Intracellular protease activation in apoptosis and cell-mediated cytotoxicity characterized by cell-permeable fluorogenic protease substrates

    Institute of Scientific and Technical Information of China (English)

    Beverly Z Packard; Akira Komoriya

    2008-01-01

    Over the past decade the importance of signaling from reporter molecules inside live cells and tissues has been clearly established. Biochemical events related to inflammation, tumor metastasis and proliferation, and viral infectivity and replication are examples of processes being further defined as more molecular tools for live cell measurements become available. Moreover, in addition to quantitating parameters related to physiologic processes, real-time imaging of molecular interactions that compose basic cellular activities are providing insights into understanding disease mechanisms as well as extending clinical efficacy of therapeutic regimens. In this review the use of highly cell-permeable fluorogenic substrates that report protease activities inside live cells is described; applications to defining the molecular events of two cellular processes, i.e., apoptosis and cell-mediated cytotoxicity, are then illustrated.

  2. A Neutralizing Antibody Assay Based on a Reporter of Antibody-Dependent Cell-Mediated Cytotoxicity.

    Science.gov (United States)

    Wu, Yuling; Li, Jia J; Kim, Hyun Jun; Liu, Xu; Liu, Weiyi; Akhgar, Ahmad; Bowen, Michael A; Spitz, Susan; Jiang, Xu-Rong; Roskos, Lorin K; White, Wendy I

    2015-11-01

    Benralizumab is a humanized anti-IL5 receptor α (IL5Rα) monoclonal antibody (mAb) with enhanced (afucosylation) antibody-dependent cell-mediated cytotoxicity (ADCC) function. An ADCC reporter cell-based neutralizing antibody (NAb) assay was developed and characterized to detect NAb against benralizumab in human serum to support the clinical development of benralizumab. The optimal ratio of target cells to effector cells was 3:1. Neither parental benralizumab (fucosylated) nor benralizumab Fab resulted in ADCC activity, confirming the requirement for ADCC activity in the NAb assay. The serum tolerance of the cells was determined to be 2.5%. The cut point derived from normal and asthma serum samples was comparable. The effective range of benralizumab was determined, and 35 ng/mL [80% maximal effective concentration (EC80)] was chosen as the standard concentration to run in the assessment of NAb. An affinity purified goat anti-benralizumab polyclonal idiotype antibody preparation was shown to have NAb since it inhibited ADCC activity in a dose-dependent fashion. The low endogenous concentrations of IL5 and soluble IL5 receptor (sIL5R) did not demonstrate to interfere with the assay. The estimated assay sensitivities at the cut point were 1.02 and 1.10 μg/mL as determined by the surrogate neutralizing goat polyclonal and mouse monoclonal anti-drug antibody (ADA) controls, respectively. The assay can detect NAb (at 2.5 μg/mL) in the presence of 0.78 μg/mL benralizumab. The assay was not susceptible to non-specific matrix effects. This study provides an approach and feasibility of developing an ADCC cell-based NAb assay to support biopharmaceuticals with an ADCC function. PMID:26205082

  3. Integrin receptors on tumor cells facilitate NK cell-mediated antibody-dependent cytotoxicity.

    Science.gov (United States)

    Anikeeva, Nadia; Steblyanko, Maria; Fayngerts, Svetlana; Kopylova, Natalya; Marshall, Deborah J; Powers, Gordon D; Sato, Takami; Campbell, Kerry S; Sykulev, Yuri

    2014-08-01

    NK cells that mediate ADCC play an important role in tumor-specific immunity. We have examined factors limiting specific lysis of tumor cells by CD16.NK-92 cells induced by CNTO 95LF antibodies recognizing αV integrins that are overexpressed on many tumor cells. Although all tested tumor cells were killed by CD16.NK-92 effectors in the presence of the antibodies, the killing of target cells with a low level of ICAM-1 expression revealed a dramatic decrease in their specific lysis at high antibody concentration, revealing a dose limiting effect. A similar effect was also observed with primary human NK cells. The effect was erased after IFN-γ treatment of tumor cells resulting in upregulation of ICAM-1. Furthermore, killing of the same tumor cells induced by Herceptin antibody was significantly impaired in the presence of CNTO 95Ala-Ala antibody variant that blocks αV integrins but is incapable of binding to CD16. These data suggest that αV integrins on tumor cells could compensate for the loss of ICAM-1 molecules, thereby facilitating ADCC by NK cells. Thus, NK cells could exercise cytolytic activity against ICAM-1 deficient tumor cells in the absence of proinflammatory cytokines, emphasizing the importance of NK cells in tumor-specific immunity at early stages of cancer. PMID:24810893

  4. Relationship of oxidant-mediated cytotoxicity to phospholipid metabolism in endothelial cells

    International Nuclear Information System (INIS)

    Exposure to oxidants permeabilizes cell membranes and liberates unesterified fatty acids (UFA) in a variety of cell types, including endothelial cells. Products of phospholipase activity, particularly UFA and lysophosphatides, possess potent detergent-like properties, and we postulated that oxidant injury might be mediated by the accumulation of these toxic phospholipase products. Several radiolabels were incorporated into defined positions in the phospholipids of cultured, confluent bovine pulmonary endothelial cells (BPAEC). The release of radiolabeled fatty acids and the accumulation of cell-associated phospholipase products were measured and compared to a standard cytotoxicity assay (51Cr release) in response to an oxidant stress, in this case 0.1 to 10 mM hydrogen peroxide (H2O2). H2O2 caused time- and dose-dependent 51Cr release as well as liberation of saturated ([14C]stearic acid) and unsaturated ([3H]arachidonic acid) fatty acids and the accumulation of phospholipase A2 and C products. The ability of BPAEC to incorporate UFA into complex phospholipids was shown to be severely impaired in the presence of H2O2. Further studies showed that H2O2 caused depletion of BPAEC adenosine triphosphate (ATP) content to undetectable levels, and that the depletion of cellular ATP by iodoacetic acid induced substantial release of [3H]arachidonic acid but not [14C]stearic acid from BPAEC. This finding suggests that release of UFA in response to an oxidant stress may be due in part to a defect in ATP-dependent reacylation pathways and need not reflect any increase in phospholipase activities. Also unsaturated fatty acids were found to be toxic to BPAEC upon adding them to supernatants of cultured monolayers

  5. Antibody-dependent cell-mediated cytotoxicity (ADCC) toward human O+ red cells coated with anti-D antibody: comparison between lymphocyte and monocyte ADCC activity.

    OpenAIRE

    Sunada,Mitsutoshi; Suzuki, Shinya; Ota, Zensuke

    1985-01-01

    We investigated the antibody dependent cell-mediated cytotoxicity (ADCC) of lymphocytes and monocytes toward human O+ red cells coated with anti-D antibody using a 51Cr release assay. Lysis of sensitized red cells by lymphocytes occurred rapidly, but monocyte-mediated lysis occurred slowly. This difference might be due to postphagocytic 51Cr release by monocytes. ADCC of lymphocytes increased in proportion to the effector cell number, but large amounts of antibodies were required. In contrast...

  6. Nickel (II)-induced cytotoxicity and apoptosis in human proximal tubule cells through a ROS- and mitochondria-mediated pathway

    International Nuclear Information System (INIS)

    Nickel compounds are known to be toxic and carcinogenic in kidney and lung. In this present study, we investigated the roles of reactive oxygen species (ROS) and mitochondria in nickel (II) acetate-induced cytotoxicity and apoptosis in the HK-2 human renal cell line. The results showed that the cytotoxic effects of nickel (II) involved significant cell death and DNA damage. Nickel (II) increased the generation of ROS and induced a noticeable reduction of mitochondrial membrane potential (MMP). Analysis of the sub-G1 phase showed a significant increase in apoptosis in HK-2 cells after nickel (II) treatment. Pretreatment with N-acetylcysteine (NAC) not only inhibited nickel (II)-induced cell death and DNA damage, but also significantly prevented nickel (II)-induced loss of MMP and apoptosis. Cell apoptosis triggered by nickel (II) was characterized by the reduced protein expression of Bcl-2 and Bcl-xL and the induced the protein expression of Bad, Bcl-Xs, Bax, cytochrome c and caspases 9, 3 and 6. The regulation of the expression of Bcl-2-family proteins, the release of cytochrome c and the activation of caspases 9, 3 and 6 were inhibited in the presence of NAC. These results suggest that nickel (II) induces cytotoxicity and apoptosis in HK-2 cells via ROS generation and that the mitochondria-mediated apoptotic signaling pathway may be involved in the positive regulation of nickel (II)-induced renal cytotoxicity.

  7. Cells of the J774 macrophage cell line are primed for antibody-dependent cell-mediated cytotoxicity following exposure to γ-irradiation

    International Nuclear Information System (INIS)

    Activation of macrophages (M phi) for host defense against tumor cells follows a sequence of priming events followed by an initiating stimulus that results in production and release of cytotoxic molecules that mediate target cell killing. The authors have developed a model to study specific macrophage cytotoxicity in vitro utilizing a cultured murine M phi cell line, J774. Specific cytotoxicity of cultured human gastrointestinal tumor cells is achieved in the presence of murine IgG2a monoclonal antibody (mAb) 17-1-A. The ability of these cells to mediate antibody-dependent cell-mediated cytotoxicity (ADCC) is greatly enhanced following gamma-irradiation. ADCC can be demonstrated at mAb 17-1-A concentrations greater than or equal to 1 microgram/ml and effector/target cell ratios greater than or equal to 2. Exposure to doses greater than or equal to 10 Gy of gamma-irradiation increases ADCC threefold. Varying the duration from J774 M phi exposure to γ-irradiation until addition of antibody-coated target cells showed that the primed state for ADCC is stable for at least 8 days but approximately 24 hr is required for complete development of the primed state. mAb-dependent target cell death begins 8 hr after addition of mAb and labeled target cells to primed effector cells and is complete by 24 hr. Incubation of unirradiated J774 M phi effector cells with recombinant murine interferon-γ (rmIFN-γ) also results in enhanced ADCC, but the extent of target cell killing achieved is less than that following priming by γ-irradiation. Concomitant priming of γ-irradiated J774 M phi with rmIFN-γ increases the extent of ADCC. Further study of irradiated J774 cells may elucidate the molecular pathways utilized by M phi for achieving and maintaining the primed state for ADCC

  8. Cells of the J774 macrophage cell line are primed for antibody-dependent cell-mediated cytotoxicity following exposure to. gamma. -irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Duerst, R.; Werberig, K. (University of Rochester Medical Center, New York (USA))

    1991-09-01

    Activation of macrophages (M phi) for host defense against tumor cells follows a sequence of priming events followed by an initiating stimulus that results in production and release of cytotoxic molecules that mediate target cell killing. The authors have developed a model to study specific macrophage cytotoxicity in vitro utilizing a cultured murine M phi cell line, J774. Specific cytotoxicity of cultured human gastrointestinal tumor cells is achieved in the presence of murine IgG2a monoclonal antibody (mAb) 17-1-A. The ability of these cells to mediate antibody-dependent cell-mediated cytotoxicity (ADCC) is greatly enhanced following gamma-irradiation. ADCC can be demonstrated at mAb 17-1-A concentrations greater than or equal to 1 microgram/ml and effector/target cell ratios greater than or equal to 2. Exposure to doses greater than or equal to 10 Gy of gamma-irradiation increases ADCC threefold. Varying the duration from J774 M phi exposure to {gamma}-irradiation until addition of antibody-coated target cells showed that the primed state for ADCC is stable for at least 8 days but approximately 24 hr is required for complete development of the primed state. mAb-dependent target cell death begins 8 hr after addition of mAb and labeled target cells to primed effector cells and is complete by 24 hr. Incubation of unirradiated J774 M phi effector cells with recombinant murine interferon-{gamma} (rmIFN-{gamma}) also results in enhanced ADCC, but the extent of target cell killing achieved is less than that following priming by {gamma}-irradiation. Concomitant priming of {gamma}-irradiated J774 M phi with rmIFN-{gamma} increases the extent of ADCC. Further study of irradiated J774 cells may elucidate the molecular pathways utilized by M phi for achieving and maintaining the primed state for ADCC.

  9. Cytotoxicity mechanism of α-MMC in normal liver cells through LRP1 mediated endocytosis and JNK activation.

    Science.gov (United States)

    Wang, Ling; Shen, Fubing; Zhang, Min; He, Qianchuan; Zhao, Hui; Yu, Xiaoping; Yang, Shuxia; Liu, Yang; Deng, Nianhua; Zheng, Juecun; Zhu, Lixia; Liu, Xiaolan

    2016-05-16

    Alpha-momorcharin (α-MMC), a type I ribosome-inactivating protein isolated from Momordica charantia, is a potential drug candidate with strong anti-tumor activity. However, α-MMC has a severe hepatotoxicity when applied in vivo, which may greatly hinders its use in clinic in the future. The biological mechanism of hepatotoxicity induced by α-MMC is largely unknown, especially the mechanism by which α-MMC enters the hepatocytes. In this study, we investigated α-MMC-induced cytotoxicity in normal liver L02 cell line as well as the mechanism underlying it. As expected, α-MMC is more toxic in L02 cells than in various normal cells from other organs. The cytotoxic effect of α-MMC on L02 cells is found to be mediated through cell apoptosis as detected by flow cytometry and fluorescence microscopy. Importantly, α-MMC was shown to bind to a specific receptor on cell membrane, as the density of the cell membrane receptor is closely related to both the amount of α-MMC endocytosed and the cytotoxicity in different cell lines. By using LRP1 competitive inhibitor α2-M or siRNA targeting LRP1, we further identified that LRP1 protein served as the membrane receptor for α-MMC. Both α2-M and siRNA targeting LRP1 can significantly inhibit α-MMC's endocytosis as well as its cytotoxicity in L02 cells. In addition, it was found that α-MMC can activate the JNK signalling pathways via LRP1 in L02 cells. As JNK activation often leads to cell apoptosis, the activation of JNK may play an important role in α-MMC-induced cytotoxicity. To our knowledge, this is the first report showing that LRP1 mediates the cytotoxicity of α-MMC through (1) endocytosis and induced apoptosis and (2) the activation of the JNK pathway. Our findings shed light on the fundamental mechanism of hepatotoxicity of α-MMC and offer reference to understand its mechanism of lymphocytotoxicity and neurotoxicity. PMID:27262837

  10. NK-cell-dependent killing of colon carcinoma cells is mediated by natural cytotoxicity receptors (NCRs) and stimulated by parvovirus infection of target cells

    International Nuclear Information System (INIS)

    Investigating how the immune system functions during malignancies is crucial to developing novel therapeutic strategies. Natural killer (NK) cells, an important component of the innate immune system, play a vital role in immune defense against tumors and virus-infected cells. The poor survival rate in colon cancer makes it particularly important to develop novel therapeutic strategies. Oncolytic viruses, in addition to lysing tumor cells, may have the potential to augment antitumor immune responses. In the present study, we investigate the role of NK cells and how parvovirus H-1PV can modulate NK-cell mediated immune responses against colon carcinoma. Human NK cells were isolated from the blood of healthy donors. The cytotoxicity and antibody-mediated inhibition of NK cells were measured in chromium release assays. Phenotypic assessment of colon cancer and dendritic cells was done by FACS. The statistical significance of the results was calculated with Student’s t test (*p <0.05; **, p < 0.01; ***, p < 0.001). We show that IL-2-activated human NK cells can effectively kill colon carcinoma cells. Killing of colon carcinoma cells by NK cells was further enhanced upon infection of the former cells with parvovirus H-1PV. H-1PV has potent oncolytic activity against various tumors, yet its direct killing effect on colon carcinoma cells is limited. The cytotoxicity of NK cells towards colon carcinoma cells, both mock- and H-1PV-infected, was found to be mostly mediated by a combination of natural cytotoxicity receptors (NCRs), namely NKp30, 44, and 46. Colon carcinoma cells displayed low to moderate expression of NK cell ligands, and this expression was modulated upon H-1PV infection. Lysates of H-1PV-infected colon carcinoma cells were found to increase MHC class II expression on dendritic cells. Altogether, these data suggest that IL-2-activated NK cells actively kill colon carcinoma cells and that this killing is mediated by several natural cytotoxicity receptors

  11. Cancer cell specific cytotoxic gene expression mediated by ARF tumor suppressor promoter constructs.

    Science.gov (United States)

    Kurayoshi, Kenta; Ozono, Eiko; Iwanaga, Ritsuko; Bradford, Andrew P; Komori, Hideyuki; Ohtani, Kiyoshi

    2014-07-18

    In current cancer treatment protocols, such as radiation and chemotherapy, side effects on normal cells are major obstacles to radical therapy. To avoid these side effects, a cancer cell-specific approach is needed. One way to specifically target cancer cells is to utilize a cancer specific promoter to express a cytotoxic gene (suicide gene therapy) or a viral gene required for viral replication (oncolytic virotherapy). For this purpose, the selected promoter should have minimal activity in normal cells to avoid side effects, and high activity in a wide variety of cancers to obtain optimal therapeutic efficacy. In contrast to the AFP, CEA and PSA promoters, which have high activity only in a limited spectrum of tumors, the E2F1 promoter exhibits high activity in wide variety of cancers. This is based on the mechanism of carcinogenesis. Defects in the RB pathway and activation of the transcription factor E2F, the main target of the RB pathway, are observed in almost all cancers. Consequently, the E2F1 promoter, which is mainly regulated by E2F, has high activity in wide variety of cancers. However, E2F is also activated by growth stimulation in normal growing cells, suggesting that the E2F1 promoter may also be highly active in normal growing cells. In contrast, we found that the tumor suppressor ARF promoter is activated by deregulated E2F activity, induced by forced inactivation of pRB, but does not respond to physiological E2F activity induced by growth stimulation. We also found that the deregulated E2F activity, which activates the ARF promoter, is detected only in cancer cell lines. These observations suggest that ARF promoter is activated by E2F only in cancer cells and therefore may be more cancer cell-specific than E2F1 promoter to drive gene expression. We show here that the ARF promoter has lower activity in normal growing fibroblasts and shows higher cancer cell-specificity compared to the E2F1 promoter. We also demonstrate that adenovirus expressing HSV

  12. Reactive oxygen species-mediated apoptosis contributes to chemosensitization effect of saikosaponins on cisplatin-induced cytotoxicity in cancer cells

    Directory of Open Access Journals (Sweden)

    He Fan

    2010-12-01

    Full Text Available Abstract Background Saikosaponin-a and -d, two naturally occurring compounds derived from Bupleurum radix, have been shown to exert anti-cancer activity in several cancer cell lines. However, the effect of combination of saikosaponins with chemotherapeutic drugs has never been addressed. Thus, we investigated whether these two saikosaponins have chemosensitization effect on cisplatin-induced cancer cell cytotoxicity. Methods Two cervical cancer cell lines, HeLa and Siha, an ovarian cancer cell line, SKOV3, and a non-small cell lung cancer cell line, A549, were treated with saikosaponins or cisplatin individually or in combination. Cell death was quantitatively detected by the release of lactate dehydrogenase (LDH using a cytotoxicity detection kit. Cellular ROS was analyzed by flow cytometry. Apoptosis was evaluated by AO/EB staining, flow cytometry after Anexin V and PI staining, and Western blot for caspase activation. ROS scavengers and caspase inhibitor were used to determine the roles of ROS and apoptosis in the effects of saikosaponins on cisplatin-induced cell death. Results Both saikosaponin-a and -d sensitized cancer cells to cisplatin-induced cell death in a dose-dependent manner, which was accompanied with induction of reactive oxygen species (ROS accumulation. The dead cells showed typical apoptotic morphologies. Both early apoptotic and late apoptotic cells detected by flow cytometry were increased in saikosaponins and cisplatin cotreated cells, accompanied by activation of the caspase pathway. The pan-caspase inhibitor z-VAD and ROS scanvengers butylated hydroxyanisole (BHA and N-acetyl-L-cysteine (NAC dramatically suppressed the potentiated cytotoxicity achieved by combination of saikosaponin-a or -d and cisplatin. Conclusions These results suggest that saikosaponins sensitize cancer cells to cisplatin through ROS-mediated apoptosis, and the combination of saikosaponins with cisplatin could be an effective therapeutic strategy.

  13. Prospective Evaluation of Cetuximab-Mediated Antibody-Dependent Cell Cytotoxicity in Metastatic Colorectal Cancer Patients Predicts Treatment Efficacy.

    Science.gov (United States)

    Trotta, Anna Maria; Ottaiano, Alessandro; Romano, Carmela; Nasti, Guglielmo; Nappi, Anna; De Divitiis, Chiara; Napolitano, Maria; Zanotta, Serena; Casaretti, Rossana; D'Alterio, Crescenzo; Avallone, Antonio; Califano, Daniela; Iaffaioli, Rosario Vincenzo; Scala, Stefania

    2016-04-01

    Cetuximab is a monoclonal antibody to the EGFR that induces antibody-dependent cell cytotoxicity (ADCC) through Fcγ receptors on immune cells. Although SNPs in genes encoding Fcγ receptors are functionally relevant to cetuximab-mediated ADCC in colorectal cancer, a direct correlation betweenin vitroADCC and clinical response to cetuximab is not defined. We therefore enrolled 96 consecutive metastatic colorectal cancer (mCRC) patients at diagnosis in a study that assessed FcγR status and cetuximab-mediated ADCC. Patients carrying the FcγRIIaHalleles 131H/Hand 131H/Rhad significantly higher ADCC compared with patients with the 131R/Ralleles (P= 0.013). Patients carrying FcγRIIIa genotypes with theValleles 158V/Vand 158V/Fdisplayed higher ADCC compared with patients carrying the 158F/Fgenotype (P= 0.001). Progression-free survival of patients with an FcγRIIIa 158Vallele was significantly longer compared with patients carrying 158F/F(P= 0.05), whereas no significant difference was observed for overall survival. Twenty-eight of 50 mCRC patients with wild-type KRAS received cetuximab. The average ADCC-mediated killing was 30% of assay targets for patients who experienced cetuximab complete or partial response, 21% in patients with stable disease and 9% in patients with progressive disease. To characterize basal natural killer (NK) activity, cytotoxicity was evaluated in 39 of 96 mCRC patients. Patients who responded to first-line treatment had higher NK-cell cytotoxicity. Thus, although limited to this cohort of patients,in vitrocetuximab-mediated ADCC correlated with FcγR polymorphisms and predicted cetuximab responsiveness.Cancer Immunol Res; 4(4); 366-74. ©2016 AACR. PMID:26817995

  14. Development of IgG Mediated Antibody Dependent Cell-mediated Cytotoxicity (ADCC) in the Serum and Genital Mucosa of HIV Seroconverters

    OpenAIRE

    Aziz, Mariam; Mahmood, Fareeha; Mata, Mariana; Durkin, Helen G.; Liu, Chenglong; Greenblatt, Ruth M.; Nowicki, Marek; Elizabeth T Golub; Anastos, Kathryn; French, Audrey L.; Baum, Linda L.

    2015-01-01

    Background We measured antibody-dependent cell mediated cytotoxicity (ADCC) activity in serum and genital fluids of heterosexually exposed women during HIV seroconversion. Methods Plasma and cervico-vaginal lavage (CVL) fluid from 11 seroconverters (SC) were analyzed biannually from one year pre- to 6 year post-seroconversion using a 51Cr-release assay to measure HIV-1 gp120 specific ADCC. Results No SC had significant HIV specific CVL ADCC activity before seroconversion or until 1.5 yr after...

  15. Oxidative stress-mediated cytotoxicity of zirconia nanoparticles on PC12 and N2a cells

    International Nuclear Information System (INIS)

    In recent years, there is a growing interest in the application of nanoparticles like zirconium dioxide (zirconia <100 nm), for many purposes. Since a comprehensive study on the toxic effects of zirconia has not been done, we decided to investigate the effects of zirconia nanoparticles on cultured PC12 and N2a cells. In this study, cytotoxic effect of different concentrations of zirconia nanoparticles at three different time intervals were evaluated using MTT and ROS (reactive oxygen species) assays. Also, Lipid peroxidation, glutathione (GSH) content changes, and DNA damage were measured. Zirconia nanoparticles caused a significant reduction in cell viability and GSH content of the cells, and induce a significant increase in intracellular ROS and MDA content of PC12 and N2a cells. Moreover, it increases the percentage of DNA tail of treated cells as compared with control group. Zirconia nanoparticles have cytotoxic and genotoxic effects in PC12 and N2a cells in a time and concentration-dependent manner in concentration more than 31 µg/mL

  16. Oxidative stress-mediated cytotoxicity of zirconia nanoparticles on PC12 and N2a cells

    Energy Technology Data Exchange (ETDEWEB)

    Asadpour, Elham [Shiraz University of Medical Sciences, Anesthesiology and Critical Care Research Center (Iran, Islamic Republic of); Sadeghnia, Hamid R. [Mashhad University of Medical Sciences, Department of Pharmacology, Faculty of Medicine (Iran, Islamic Republic of); Ghorbani, Ahmad [Mashhad University of Medical Sciences, Pharmacological Research Center of Medicinal Plants (Iran, Islamic Republic of); Sedaghat, Mehran, E-mail: m-sedaghat81@yahoo.com [Mashhad University of Medical Sciences, Department of Neurosurgery (Iran, Islamic Republic of); Boroushaki, Mohammad T., E-mail: boroushakimt@mums.ac.ir [Mashhad University of Medical Sciences, Department of Pharmacology, Faculty of Medicine (Iran, Islamic Republic of)

    2016-01-15

    In recent years, there is a growing interest in the application of nanoparticles like zirconium dioxide (zirconia <100 nm), for many purposes. Since a comprehensive study on the toxic effects of zirconia has not been done, we decided to investigate the effects of zirconia nanoparticles on cultured PC12 and N2a cells. In this study, cytotoxic effect of different concentrations of zirconia nanoparticles at three different time intervals were evaluated using MTT and ROS (reactive oxygen species) assays. Also, Lipid peroxidation, glutathione (GSH) content changes, and DNA damage were measured. Zirconia nanoparticles caused a significant reduction in cell viability and GSH content of the cells, and induce a significant increase in intracellular ROS and MDA content of PC12 and N2a cells. Moreover, it increases the percentage of DNA tail of treated cells as compared with control group. Zirconia nanoparticles have cytotoxic and genotoxic effects in PC12 and N2a cells in a time and concentration-dependent manner in concentration more than 31 µg/mL.

  17. Cancer cell specific cytotoxic gene expression mediated by ARF tumor suppressor promoter constructs

    International Nuclear Information System (INIS)

    Highlights: • ARF promoter showed higher responsiveness to deregulated E2F activity than the E2F1 promoter. • ARF promoter showed higher cancer cell-specificity than E2F1 promoter to drive gene expression. • HSV-TK driven by ARF promoter showed higher cancer cell-specific cytotoxicity than that driven by E2F1 promoter. - Abstract: In current cancer treatment protocols, such as radiation and chemotherapy, side effects on normal cells are major obstacles to radical therapy. To avoid these side effects, a cancer cell-specific approach is needed. One way to specifically target cancer cells is to utilize a cancer specific promoter to express a cytotoxic gene (suicide gene therapy) or a viral gene required for viral replication (oncolytic virotherapy). For this purpose, the selected promoter should have minimal activity in normal cells to avoid side effects, and high activity in a wide variety of cancers to obtain optimal therapeutic efficacy. In contrast to the AFP, CEA and PSA promoters, which have high activity only in a limited spectrum of tumors, the E2F1 promoter exhibits high activity in wide variety of cancers. This is based on the mechanism of carcinogenesis. Defects in the RB pathway and activation of the transcription factor E2F, the main target of the RB pathway, are observed in almost all cancers. Consequently, the E2F1 promoter, which is mainly regulated by E2F, has high activity in wide variety of cancers. However, E2F is also activated by growth stimulation in normal growing cells, suggesting that the E2F1 promoter may also be highly active in normal growing cells. In contrast, we found that the tumor suppressor ARF promoter is activated by deregulated E2F activity, induced by forced inactivation of pRB, but does not respond to physiological E2F activity induced by growth stimulation. We also found that the deregulated E2F activity, which activates the ARF promoter, is detected only in cancer cell lines. These observations suggest that ARF promoter

  18. Cancer cell specific cytotoxic gene expression mediated by ARF tumor suppressor promoter constructs

    Energy Technology Data Exchange (ETDEWEB)

    Kurayoshi, Kenta [Department of Bioscience, School of Science and Technology, Kwansei Gakuin University, 2-1 Gakuen, Sanda, Hyogo 669-1337 (Japan); Ozono, Eiko [Centre for Molecular Oncology, Barts Cancer Institute, Queen Mary, University of London, John Vane Science Centre, Charterhouse Square, London EC1M 6BQ (United Kingdom); Iwanaga, Ritsuko; Bradford, Andrew P. [Department of Obstetrics and Gynecology, University of Colorado School of Medicine, Anschutz Medical Campus, 12800 East 19th Avenue, Aurora, CO 80045 (United States); Komori, Hideyuki [Center for Stem Cell Biology, Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109 (United States); Ohtani, Kiyoshi, E-mail: btm88939@kwansei.ac.jp [Department of Bioscience, School of Science and Technology, Kwansei Gakuin University, 2-1 Gakuen, Sanda, Hyogo 669-1337 (Japan)

    2014-07-18

    Highlights: • ARF promoter showed higher responsiveness to deregulated E2F activity than the E2F1 promoter. • ARF promoter showed higher cancer cell-specificity than E2F1 promoter to drive gene expression. • HSV-TK driven by ARF promoter showed higher cancer cell-specific cytotoxicity than that driven by E2F1 promoter. - Abstract: In current cancer treatment protocols, such as radiation and chemotherapy, side effects on normal cells are major obstacles to radical therapy. To avoid these side effects, a cancer cell-specific approach is needed. One way to specifically target cancer cells is to utilize a cancer specific promoter to express a cytotoxic gene (suicide gene therapy) or a viral gene required for viral replication (oncolytic virotherapy). For this purpose, the selected promoter should have minimal activity in normal cells to avoid side effects, and high activity in a wide variety of cancers to obtain optimal therapeutic efficacy. In contrast to the AFP, CEA and PSA promoters, which have high activity only in a limited spectrum of tumors, the E2F1 promoter exhibits high activity in wide variety of cancers. This is based on the mechanism of carcinogenesis. Defects in the RB pathway and activation of the transcription factor E2F, the main target of the RB pathway, are observed in almost all cancers. Consequently, the E2F1 promoter, which is mainly regulated by E2F, has high activity in wide variety of cancers. However, E2F is also activated by growth stimulation in normal growing cells, suggesting that the E2F1 promoter may also be highly active in normal growing cells. In contrast, we found that the tumor suppressor ARF promoter is activated by deregulated E2F activity, induced by forced inactivation of pRB, but does not respond to physiological E2F activity induced by growth stimulation. We also found that the deregulated E2F activity, which activates the ARF promoter, is detected only in cancer cell lines. These observations suggest that ARF promoter

  19. Dichlorophen and Dichlorovos mediated genotoxic and cytotoxic assessment on root meristem cells of Allium cepa

    Directory of Open Access Journals (Sweden)

    Sibhghatulla Shaikh

    2012-06-01

    Full Text Available Plants are direct recipients of agro – toxics and therefore important materials for assessing environmental chemicals for genotoxicity. The meristematic mitotic cell of Allium cepa is an efficient cytogenetic material for chromosome aberration assay on environmental pollutants. Onion root tips were grown on moistened filter paper in petri dish at room temperature. Germinated root tips were then exposed to three concentrations of each pesticide for 24 h. About 1 – 2 mm length of root tip was cut, fixed in cornoy’s fixative, hydrolyzed in warm 1 N HCL, stained with acetocarmine and squashed on glass slide. About 3000 cells were scored and classified into interphase and normal or aberrant division stage. Cytotoxicity was determined by comparing the mitotic index (MI of treated cells with that of the negative control. The MI of cells treated with Dichlorophen and Dichlorovos at one or more concentration was half or less than that of control are said to be cytotoxic. Genotoxicity was measured by comparing the number of cells/1000 in aberrant division stages at each dose with the negative control using Mann – Whitney U test. Both Dichlorophen and Dichlorovos are genotoxic at higher concentrations i.e. 0.001%, 0.002% and 0.028%, 0.056% inducing chromosome fragment, chromosome lagging and bridges, stick chromosome and multipolar anaphase.

  20. Susceptibility of adherent versus suspension target cells derived from adherent tissue culture lines to cell-mediated cytotoxicity in rapid 51Cr-release assays

    International Nuclear Information System (INIS)

    Preparation of target cells from tissue culture lines which grow adherent to tissue culture vessels is often desirable for tests of cell-mediated cytotoxicity (CMC). In the present study the authors used cells derived from adherent tissue culture lines to compare the merits of suspension vs. adherent target cells in short-term 51Cr-release assays. Cytotoxic activity of murine spleen cells sensitized in vitro against allogeneic spleen cells or syngeneic sarcoma cells was tested with fibroblast or sarcoma target cells. In parallel tests, aliquots of tissue culture lines were detached and used as either suspension or adherent target cells in CMC assays, matching the concentrations of suspension and adherent target cells. In both allogeneic and syngeneic combinations adherent target cells released less 51Cr spontaneously and were more susceptible to CMC than their suspension counterparts. (Auth.)

  1. γδ T Cell-Mediated Antibody-Dependent Cellular Cytotoxicity with CD19 Antibodies Assessed by an Impedance-Based Label-Free Real-Time Cytotoxicity Assay

    OpenAIRE

    Seidel, Ursula Jördis Eva; Vogt, Fabian; Grosse-Hovest, Ludger; Jung, Gundram; Handgretinger, Rupert; Lang, Peter

    2014-01-01

    γδ T cells are not MHC restricted, elicit cytotoxicity against various malignancies, are present in early post-transplant phases in novel stem cell transplantation strategies and have been shown to mediate antibody-dependent cellular cytotoxicity (ADCC) with monoclonal antibodies (mAbs). These features make γδ T cells promising effector cells for antibody-based immunotherapy in pediatric patients with B-lineage acute lymphoblastic leukemia (ALL). To evaluate combination of human γδ T cells wi...

  2. Potential for Natural Killer Cell-Mediated Antibody-Dependent Cellular Cytotoxicity for Control of Human Cytomegalovirus

    Directory of Open Access Journals (Sweden)

    Rebecca J. Aicheler

    2013-12-01

    Full Text Available Human cytomegalovirus (HCMV is an important pathogen that infects the majority of the population worldwide, yet, currently, there is no licensed vaccine. Despite HCMV encoding at least seven Natural Killer (NK cell evasion genes, NK cells remain critical for the control of infection in vivo. Classically Antibody-Dependent Cellular Cytotoxicity (ADCC is mediated by CD16, which is found on the surface of the NK cell in a complex with FcεRI-γ chains and/or CD3ζ chains. Ninety percent of NK cells express the Fc receptor CD16; thus, they have the potential to initiate ADCC. HCMV has a profound effect on the NK cell repertoire, such that up to 10-fold expansions of NKG2C+ cells can be seen in HCMV seropositive individuals. These NKG2C+ cells are reported to be FcεRI-γ deficient and possess variable levels of CD16+, yet have striking ADCC functions. A subset of HCMV cell surface proteins will induce robust antibody responses that could render cells susceptible to ADCC. We will consider how the strong anti-HCMV function of NKG2C+ FcεRI-γ-deficient NK cells could potentially be harnessed in the clinic to treat patients suffering from HCMV disease and in the development of an efficacious HCMV vaccine.

  3. Cytotoxicity of obacunone and obacunone glucoside in human prostate cancer cells involves Akt-mediated programmed cell death

    International Nuclear Information System (INIS)

    Highlights: • Possible mechanism of inhibiting LNCaP cells proliferation by obacunone and obacunone glucoside is demonstrated for the first time. • Inhibition of LNCaP cells by limonoids though induction of programmed cell death, inhibition of cell signaling and inflammatory pathways. • Limonoids exhibited multi-mode inhibition of androgen expression in LNCaP cells. - Abstract: Obacunone and obacunone glucoside (OG) are naturally occurring triterpenoids commonly found in citrus and other plants of the Rutaceae family. The current study reports the mechanism of cytotoxicity of citrus-derived obacunone and OG on human androgen-dependent prostate cancer LNCaP cells. Both limonoids exhibited time- and dose-dependent inhibition of cell proliferation, with more than 60% inhibition of cell viability at 100 μM, after 24 and 48 h. Analysis of fragmentation of DNA, activity of caspase-3, and cytosolic cytochrome-c in the cells treated with limonoids provided evidence for activation of programmed cell death by limonoids. Treatment of LNCaP cells with obacunone and OG resulted in dose-dependent changes in expression of proteins responsible for the induction of programmed cell death through the intrinsic pathway and down-regulation of Akt, a key molecule in cell signaling pathways. In addition, obacunone and OG also negatively regulated an inflammation-associated transcription factor, androgen receptor, and prostate-specific antigen, and activated proteins related to the cell cycle, confirming the ability of limonoids to induce cytotoxicity through multiple pathways. The results of this study provided, for the first time, an evidence of the cytotoxicity of obacunone and OG in androgen-dependent human prostate cancer cells

  4. γδ T cell-mediated antibody-dependent cellular cytotoxicity with CD19 antibodies assessed by an impedance-based label-free real-time cytotoxicity assay

    OpenAIRE

    Ursula Jördis Eva Seidel; Fabian eVogt; Ludger eGrosse-Hovest; Gundram eJung; Rupert eHandgretinger; Peter eLang

    2014-01-01

    γδ T cells are not MHC restricted, elicit cytotoxicity against various malignancies, are present in early post-transplant phases in novel stem cell transplantation (SCT) strategies and have been shown to mediate antibody-dependent cellular cytotoxicity (ADCC) with monoclonal antibodies (mAbs). These features make γδ T cells promising effector cells for antibody-based immunotherapy in pediatric patients with B-lineage acute lymphoblastic leukemia (ALL). To evaluate combination of human γδ T ce...

  5. Biodiesel exhaust-induced cytotoxicity and proinflammatory mediator production in human airway epithelial cells.

    Science.gov (United States)

    Mullins, Benjamin J; Kicic, Anthony; Ling, Kak-Ming; Mead-Hunter, Ryan; Larcombe, Alexander N

    2016-01-01

    Increasing use of biodiesel has prompted research into the potential health effects of biodiesel exhaust exposure. Few studies directly compare the health consequences of mineral diesel, biodiesel, or blend exhaust exposures. Here, we exposed human epithelial cell cultures to diluted exhaust generated by the combustion of Australian ultralow-sulfur-diesel (ULSD), unprocessed canola oil, 100% canola biodiesel (B100), and a blend of 20% canola biodiesel mixed with 80% ULSD. The physicochemical characteristics of the exhaust were assessed and we compared cellular viability, apoptosis, and levels of interleukin (IL)-6, IL-8, and Regulated on Activation, Normal T cell Expressed and Secreted (RANTES) in exposed cultured cells. Different fuel types produced significantly different amounts of exhaust gases and different particle characteristics. All exposures resulted in significant apoptosis and loss of viability when compared with control, with an increasing proportion of biodiesel being correlated with a decrease in viability. In most cases, exposure to exhaust resulted in an increase in mediator production, with the greatest increases most often in response to B100. Exposure to pure canola oil (PCO) exhaust did not increase mediator production, but resulted in a significant decrease in IL-8 and RANTES in some cases. Our results show that canola biodiesel exhaust exposure elicits inflammation and reduces viability of human epithelial cell cultures in vitro when compared with ULSD exhaust exposure. This may be related to an increase in particle surface area and number in B100 exhaust when compared with ULSD exhaust. Exposure to PCO exhaust elicited the greatest loss of cellular viability, but virtually no inflammatory response, likely due to an overall increase in average particle size. PMID:25045158

  6. X-linked inhibitor of apoptosis protein mediates tumor cell resistance to antibody-dependent cellular cytotoxicity.

    Science.gov (United States)

    Evans, M K; Sauer, S J; Nath, S; Robinson, T J; Morse, M A; Devi, G R

    2016-01-01

    Inflammatory breast cancer (IBC) is the deadliest, distinct subtype of breast cancer. High expression of epidermal growth factor receptors [EGFR or human epidermal growth factor receptor 2 (HER2)] in IBC tumors has prompted trials of anti-EGFR/HER2 monoclonal antibodies to inhibit oncogenic signaling; however, de novo and acquired therapeutic resistance is common. Another critical function of these antibodies is to mediate antibody-dependent cellular cytotoxicity (ADCC), which enables immune effector cells to engage tumors and deliver granzymes, activating executioner caspases. We hypothesized that high expression of anti-apoptotic molecules in tumors would render them resistant to ADCC. Herein, we demonstrate that the most potent caspase inhibitor, X-linked inhibitor of apoptosis protein (XIAP), overexpressed in IBC, drives resistance to ADCC mediated by cetuximab (anti-EGFR) and trastuzumab (anti-HER2). Overexpression of XIAP in parental IBC cell lines enhances resistance to ADCC; conversely, targeted downregulation of XIAP in ADCC-resistant IBC cells renders them sensitive. As hypothesized, this ADCC resistance is in part a result of the ability of XIAP to inhibit caspase activity; however, we also unexpectedly found that resistance was dependent on XIAP-mediated, caspase-independent suppression of reactive oxygen species (ROS) accumulation, which otherwise occurs during ADCC. Transcriptome analysis supported these observations by revealing modulation of genes involved in immunosuppression and oxidative stress response in XIAP-overexpressing, ADCC-resistant cells. We conclude that XIAP is a critical modulator of ADCC responsiveness, operating through both caspase-dependent and -independent mechanisms. These results suggest that strategies targeting the effects of XIAP on caspase activation and ROS suppression have the potential to enhance the activity of monoclonal antibody-based immunotherapy. PMID:26821068

  7. Antibody-Dependent Cell-Mediated Cytotoxicity to Hemagglutinin of Influenza A Viruses After Influenza Vaccination in Humans

    Science.gov (United States)

    Zhong, Weimin; Liu, Feng; Wilson, Jason R.; Holiday, Crystal; Li, Zhu-Nan; Bai, Yaohui; Tzeng, Wen-Pin; Stevens, James; York, Ian A.; Levine, Min Z.

    2016-01-01

    Background. Detection of neutralizing antibodies (nAbs) to influenza A virus hemagglutinin (HA) antigens by conventional serological assays is currently the main immune correlate of protection for influenza vaccines However, current prepandemic avian influenza vaccines are poorly immunogenic in inducing nAbs despite considerable protection conferred. Recent studies show that Ab-dependent cell-mediated cytotoxicity (ADCC) to HA antigens are readily detectable in the sera of healthy individuals and patients with influenza infection. Methods. Virus neutralization and ADCC activities of serum samples from individuals who received either seasonal or a stock-piled H5N1 avian influenza vaccine were evaluated by hemagglutination inhibition assay, microneutralization assay, and an improved ADCC natural killer (NK) cell activation assay. Results. Immunization with inactivated seasonal influenza vaccine led to strong expansion of both nAbs and ADCC-mediating antibodies (adccAbs) to H3 antigen of the vaccine virus in 24 postvaccination human sera. In sharp contrast, 18 individuals vaccinated with the adjuvanted H5N1 avian influenza vaccine mounted H5-specific antibodies with strong ADCC activities despite moderate virus neutralization capacity. Strength of HA-specific ADCC activities is largely associated with the titers of HA-binding antibodies and not with the fine antigenic specificity of anti-HA nAbs. Conclusions. Detection of both nAbs and adccAbs may better reflect protective capacity of HA-specific antibodies induced by avian influenza vaccines.

  8. DNA fragmentation: manifestation of target cell destruction mediated by cytotoxic T-cell lines, lymphotoxin-secreting helper T-cell clones, and cell-free lymphotoxin-containing supernatant

    International Nuclear Information System (INIS)

    A Lyt-2+, trinitrophenyl-specific, lymphotoxin-secreting, cytotoxic T-cell line, PCl 55, mediates the digestion of target cell DNA into discretely sized fragments. This phenomenon manifests itself within 30 min after effector cell encounter as measured by the release of 3H counts from target cells prelabeled with [3H]deoxythymidine and occurs even at very low effector to target cell ratios (0.25:1). A Lyt-1+, ovalbumin-specific, lymphotoxin-secreting T-helper cell clone, 5.9.24, is also able to mediate fragmentation of target cell DNA over a time course essentially indistinguishable from the cytotoxic T lymphocyte-mediated hit. Cell-free lymphotoxin-containing supernatants also cause release of DNA from targets, although they require a longer time course, on the order of 24 hr. In contrast, lysis of cells by antibody plus complement or Triton X-100 does not result in DNA release even after extended periods of incubation (24 hr). All three treatments that result in the release of DNA from cells cause fragmentation of that DNA into discretely sized pieces that are multiples of 200 base pairs. The results thus suggest that cytotoxic T cells, lymphotoxin-secreting helper clones with cytolytic activity, and lymphotoxin all effect target cell destruction by means of a similar mechanism and that observed differences in time course and the absence of target cell specificity in killing mediated by lymphotoxin may simply reflect differences in the mode of toxin delivery

  9. Cytotoxic T-Cell-Mediated Response against Yersinia pseudotuberculosis in HLA-B27 Transgenic Rat

    OpenAIRE

    Falgarone, Géraldine; Blanchard, Hervé S.; Riot, Bertrand; Simonet, Michel; Breban, Maxime

    1999-01-01

    Yersinia-induced reactive arthritis is highly associated with HLA-B27, the role of which in defense against the triggering bacteria remains unclear. The aim of this study was to examine the capacity of rats transgenic for HLA-B27 to mount a cytotoxic T-lymphocyte (CTL) response against Y. pseudotuberculosis and to determine the influence of the HLA-B27 transgene on this response. Rats transgenic for HLA-B*2705 and human β2-microglobulin of the 21-4L line, which do not spontaneously develop di...

  10. Hepatoprotective potential of Lavandula coronopifolia extracts against ethanol induced oxidative stress-mediated cytotoxicity in HepG2 cells.

    Science.gov (United States)

    Farshori, Nida Nayyar; Al-Sheddi, Ebtsam S; Al-Oqail, Mai M; Hassan, Wafaa H B; Al-Khedhairy, Abdulaziz A; Musarrat, Javed; Siddiqui, Maqsood A

    2015-08-01

    The present investigations were carried out to study the protective potential of four extracts (namely petroleum ether extract (LCR), chloroform extract (LCM), ethyl acetate extract (LCE), and alcoholic extract (LCL)) of Lavandula coronopifolia on oxidative stress-mediated cell death induced by ethanol, a known hepatotoxin in human hapatocellular carcinoma (HepG2) cells. Cells were pretreated with LCR, LCM, LCE, and LCL extracts (10-50 μg/ml) of L. coronopifolia for 24 h and then ethanol was added and incubated further for 24 h. After the exposure, cell viability using (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) and neutral red uptake assays and morphological changes in HepG2 cells were studied. Pretreatment with various extracts of L. coronpifolia was found to be significantly effective in countering the cytotoxic responses of ethanol. Antioxidant properties of these L. coronopifolia extracts against reactive oxygen species (ROS) generation, lipid peroxidation (LPO), and glutathione (GSH) levels induced by ethanol were investigated. Results show that pretreatment with these extracts for 24 h significantly inhibited ROS generation and LPO induced and increased the GSH levels reduced by ethanol. The data from the study suggests that LCR, LCM, LCE, and LCL extracts of L. coronopifolia showed hepatoprotective activity against ethanol-induced damage in HepG2 cells. However, a comparative study revealed that the LCE extract was found to be the most effective and LCL the least effective. The hepatoprotective effects observed in the study could be associated with the antioxidant properties of these extracts of L. coronopifolia. PMID:23546397

  11. Mediation of cytotoxic functions by classes and subclasses of sheep antibody reactive with cell surface immunoglobulin idiotypic and constant region determinants

    International Nuclear Information System (INIS)

    Sheep antibodies, reactive with either the idiotypic or constant region antigenic determinants of the immunoglobulin light chain in guinea-pig L2C leukaemic cells, were separated into IgM and into the two subclasses of IgG, IgG1 and IgG2. Antibody of both IgG subclasses inhibited the migration of L2C cells along plastic surfaces; IgM was only weakly inhibitory. Antibody of class IgM and of subclass IgG1 mediated complement cytotoxicity against the L2C cells whereas only that of subclass IgG2 mediated K-cell cytotoxicity; the effector arms were rabbit complement and sheep peripheral leucocytes, respectively. (author)

  12. HIV-Specific Antibody-Dependent Cellular Cytotoxicity (ADCC) -Mediating Antibodies Decline while NK Cell Function Increases during Antiretroviral Therapy (ART)

    DEFF Research Database (Denmark)

    Skov Jensen, Sanne; Fomsgaard, Anders; Borggren, Marie; Tingstedt, Jeanette Linnea; Gerstoft, Jan; Kronborg, Gitte; Rasmussen, Line Dahlerup; Pedersen, Court; Karlsson, Ingrid

    2015-01-01

    Understanding alterations in HIV-specific immune responses during antiretroviral therapy (ART), such as antibody-dependent cellular cytotoxicity (ADCC), is important in the development of novel strategies to control HIV-1 infection. This study included 53 HIV-1 positive individuals. We evaluated...... the ability of effector cells and antibodies to mediate ADCC separately and in combination using the ADCC-PanToxiLux assay. The ability of the peripheral blood mononuclear cells (PBMCs) to mediate ADCC was significantly higher in individuals who had been treated with ART before seroconversion......, compared to the individuals initiating ART at a low CD4+ T cell count (<350 cells/μl blood) and the ART-naïve individuals. The frequency of CD16 expressing natural killer (NK) cells correlated with both the duration of ART and Granzyme B (GzB) activity. In contrast, the plasma titer of antibodies mediating...

  13. Cell Death Mechanisms Induced by Cytotoxic Lymphocytes

    Institute of Scientific and Technical Information of China (English)

    Ch(a)vez-Gal(a)n L; Arenas-Del Angel MC; Zenteno E; Ch(a)vez R; Lascurain R

    2009-01-01

    One of the functions of the immune system is to recognize and destroy abnormal or infected cells to maintain homeostasis. This is accomplished by cytotoxic lymphocytes. Cytotoxicity is a highly organized multifactor process. Here, we reviewed the apoptosis pathways induced by the two main cytotoxic lymphocyte subsets, natural killer (NK) cells and CD8+T cells. In base to recent experimental evidence, we reviewed NK receptors involved in recognition of target-cell, as well as lytic molecules such as perforin, granzymes-A and -B, and granulysin. In addition, we reviewed the Fas-FasL intercellular linkage mediated pathway, and briefly the cross-linking of tumor necrosis factor (TNF) and TNF receptor pathway. We discussed three models of possible molecular interaction between lyric molecules from effector cytotoxic cells and target-cell membrane to induction of apoptosis.

  14. Cytotoxicity of carteolol to human corneal epithelial cells by inducing apoptosis via triggering the Bcl-2 family protein-mediated mitochondrial pro-apoptotic pathway.

    Science.gov (United States)

    Shan, Ming; Fan, Ting-Jun

    2016-09-01

    Carteolol is a frequently used nonselective β-adrenoceptor antagonist for glaucoma and ocular hypertension treatment, and its repeated/prolonged usage might be cytotoxic to the cornea, especially the outmost human corneal epithelium (HCEP). The aim of the present study was to characterize the cytotoxicity of carteolol to HCEP and its underlying cellular and molecular mechanisms using an in vitro model of HCEP cells. After HCEP cells were treated with carteolol at concentrations varying from 2% to 0.015625%, the cytotoxicity, apoptosis-inducing effect and pro-apoptotic pathway was investigated, respectively. Our results showed that carteolol at concentrations above 0.03125% induced time- and dose-dependent growth retardation, cytopathic morphological changes and viability decline of HCEP cells. Moreover, carteolol induced G1 phase arrest, plasma membrane permeability elevation, phosphatidylserine externalization, DNA fragmentation, and apoptotic body formation of HCEP cells. Furthermore, carteolol also induced activation of caspase-9 and -3, disruption of mitochondrial transmembrane potential, up-regulation the cytoplasmic amount of cytochrome c and apoptosis-inducing factor, and up-regulation of pro-apoptotic Bax and Bad, down-regulation of anti-apoptotic Bcl-2 and Bcl-xL. In conclusion, carteolol above 1/64 of its clinical therapeutic dosage has a time- and dose-dependent cytotoxicity to HCEP cells, which is achieved by inducing apoptosis via triggering Bcl-2 family protein-mediated mitochondrial pro-apoptotic pathway. PMID:27216471

  15. FTY720 (Fingolimod) sensitizes hepatocellular carcinoma cells to sorafenib-mediated cytotoxicity

    OpenAIRE

    Ahmed, Dilruba; de Verdier, Petra J; Ryk, Charlotta; Lunqe, Oscar; Stål, Per; Flygare, Jenny

    2015-01-01

    Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related death worldwide. The multityrosine kinase inhibitor sorafenib is used in the therapy of advanced disease. However, the effects of sorafenib are limited, and combination treatments aiming at improved survival are encouraged. The sphingosine analog FTY720 (Fingolimod), which is approved for treatment of multiple sclerosis, has shown tumor suppressive effects in cell lines and animal models of HCC. In the present study...

  16. CD8+ T-cell Cytotoxic Capacity Associated with Human Immunodeficiency Virus-1 Control Can Be Mediated through Various Epitopes and Human Leukocyte Antigen Types

    Directory of Open Access Journals (Sweden)

    Stephen A. Migueles

    2015-01-01

    Full Text Available Understanding natural immunologic control over Human Immunodeficiency Virus (HIV-1 replication, as occurs in rare long-term nonprogressors/elite controllers (LTNP/EC, should inform the design of efficacious HIV vaccines and immunotherapies. Durable control in LTNP/EC is likely mediated by highly functional virus-specific CD8+ T-cells. Protective Human Leukocyte Antigen (HLA class I alleles, like B*27 and B*57, are present in most, but not all LTNP/EC, providing an opportunity to investigate features shared by their HIV-specific immune responses. To better understand the contribution of epitope targeting and conservation to immune control, we compared the CD8+ T-cell specificity and function of B*27/57neg LTNP/EC (n = 23, B*27/57pos LTNP/EC (n = 23 and B*27/57neg progressors (n = 13. Fine mapping revealed 11 previously unreported immunodominant responses. Although B*27/57neg LTNP/EC did not target more highly conserved epitopes, their CD8+ T-cell cytotoxic capacity was significantly higher than progressors. Similar to B*27/57pos LTNP/EC, this superior cytotoxicity was mediated by preferential expansion of immunodominant responses and lysis through the predicted HLA. These findings suggest that increased CD8+ T-cell cytotoxic capacity is a common mechanism of control in most LTNP/EC regardless of HLA type. They also suggest that potent cytotoxicity can be mediated through various epitopes and HLA molecules and could, in theory, be induced in most people.

  17. FOXO3a reactivation mediates the synergistic cytotoxic effects of rapamycin and cisplatin in oral squamous cell carcinoma cells

    International Nuclear Information System (INIS)

    FOXO3a, a well-known transcriptional regulator, controls a wide spectrum of biological processes. The Phosphoinositide-3-kinase (PI3K)/Akt signaling pathway inactivates FOXO3a via phosphorylation-induced nuclear exclusion and degradation. A loss or gain of FOXO3a activity has been correlated with efficiency of chemotherapies in various cancers including oral squamous cell carcinoma (OSCC). Therefore, in the current study, we have investigated the FOXO3a activity modulating and antitumor effects of rapamycin and cisplatin in OSCC cells. Cisplatin inhibited proliferation and induced apoptosis in a dose-dependent way in OSCC Tca8113 cells. Rapamycin alone had no effect on cell proliferation and apoptosis. Rapamycin downregulated the expression of S-phase kinase associated protein-2 (Skp2) and increased the FOXO3a protein stability but induced the upregulation of feedback Akt activation-mediated FOXO3a phosphorylation. Cisplatin decreased the phosphorylation of FOXO3a via Akt inhibition. Rapamycin combined with cisplatin as its feedback Akt activation inhibitor revealed the most dramatic FOXO3a nuclear localization and reactivation with the prevention of its feedback loop and exposed significant synergistic effects of decreased cell proliferation and increased apoptosis in vitro and decreased tumor size in vivo. Furthermore, the downstream effects of FOXO3a reactivation were found to be accumulation of p27 and Bim. In conclusion, rapamycin/cisplatin combination therapy boosts synergistic antitumor effects through the significant FOXO3a reactivation in OSCC cells. These results may represent a novel mechanism by which rapamycin/cisplatin combination therapy proves to be a potent molecular-targeted strategy for OSCC.

  18. T cell-mediated cytotoxicity against p53-protein derived peptides in bulk and limiting dilution cultures of healthy donors

    DEFF Research Database (Denmark)

    Röpke, M; Regner, M; Claesson, M H;

    1995-01-01

    -I restricted epitopes for T cell recognition and p53-derived peptides have been suggested as targets for tumour-specific cytotoxic T lymphocytes (CTL). Our primary aim was to estimate the frequencies of p53-peptide reactive CTL precursors (CTLp) in peripheral blood from healthy young individuals. We selected...... wild type and mutated peptides derived from the p53 sequence with a binding motif for HLA-A2.1 molecules. Peripheral blood mononuclear cells (PBMC) from healthy HLA-A2 donors were stimulated in vitro in bulk cultures as well as in limiting dilution cultures using autologous cells pulsed with p53...... peptides as stimulator cells. T cell reactivity was observed towards both wild type and mutated p53 peptide epitopes with CTL precursor frequencies varying from 1:2 x 10(4) to 1:1.5 x 10(5). These results might suggest the presence of an ongoing immune response in normal individuals against cells...

  19. γδ T cell-mediated antibody-dependent cellular cytotoxicity with CD19 antibodies assessed by an impedance-based label-free real-time cytotoxicity assay

    Directory of Open Access Journals (Sweden)

    Ursula Jördis Eva Seidel

    2014-12-01

    Full Text Available γδ T cells are not MHC restricted, elicit cytotoxicity against various malignancies, are present in early post-transplant phases in novel stem cell transplantation (SCT strategies and have been shown to mediate antibody-dependent cellular cytotoxicity (ADCC with monoclonal antibodies (mAbs. These features make γδ T cells promising effector cells for antibody-based immunotherapy in pediatric patients with B-lineage acute lymphoblastic leukemia (ALL. To evaluate combination of human γδ T cells with CD19 antibodies for immunotherapy of B-lineage ALL, γδ T cells were expanded after a GMP-compliant protocol and ADCC of both primary and expanded γδ T cells with an Fc optimized CD19 antibody (4G7SDIE and a bispecific antibody with the specificities CD19 and CD16 (N19-C16 was evaluated in CD107a degranulation assays and intracellular cytokine staining (ICS. CD107a, TNF-α and IFN-γ expression of primary γδ T cells were significantly increased and correlated with CD16-expression of γδ T cells. γδ T cells highly expressed CD107a after expansion and no further increased expression by 4G7SDIE and N19-C16 was measured. Cytotoxicity of purified expanded γδ T cells targeting CD19-expressing cells was assessed in both europium-TDA release and in an impedance-based label-free method (using the xCELLigence system measuring γδ T cell lysis in real-time. Albeit in the 2 h end-point europium-TDA release assay no increased lysis was observed, in real-time xCELLigence assays both significant antibody-independent cytotoxicity and ADCC of γδ T cells were observed. The xCELLigence system outperformed the end-point europium-TDA release assay in sensitivity and allows drawing of conclusions to lysis kinetics of γδ T cells over prolonged periods of time periods. Combination of CD19 antibodies with primary as well as expanded γδ T cells exhibits an promising approach, which may enhance clinical outcome of patients with pediatric B-lineage ALL and

  20. γδ T Cell-Mediated Antibody-Dependent Cellular Cytotoxicity with CD19 Antibodies Assessed by an Impedance-Based Label-Free Real-Time Cytotoxicity Assay.

    Science.gov (United States)

    Seidel, Ursula Jördis Eva; Vogt, Fabian; Grosse-Hovest, Ludger; Jung, Gundram; Handgretinger, Rupert; Lang, Peter

    2014-01-01

    γδ T cells are not MHC restricted, elicit cytotoxicity against various malignancies, are present in early post-transplant phases in novel stem cell transplantation strategies and have been shown to mediate antibody-dependent cellular cytotoxicity (ADCC) with monoclonal antibodies (mAbs). These features make γδ T cells promising effector cells for antibody-based immunotherapy in pediatric patients with B-lineage acute lymphoblastic leukemia (ALL). To evaluate combination of human γδ T cells with CD19 antibodies for immunotherapy of B-lineage ALL, γδ T cells were expanded after a GMP-compliant protocol and ADCC of both primary and expanded γδ T cells with an Fc-optimized CD19 antibody (4G7SDIE) and a bi-specific antibody with the specificities CD19 and CD16 (N19-C16) was evaluated in CD107a-degranulation assays and intracellular cytokine staining. CD107a, TNFα, and IFNγ expression of primary γδ T cells were significantly increased and correlated with CD16-expression of γδ T cells. γδ T cells highly expressed CD107a after expansion and no further increased expression by 4G7SDIE and N19-C16 was measured. Cytotoxicity of purified expanded γδ T cells targeting CD19-expressing cells was assessed in both europium-TDA release and in an impedance-based label-free method (using the xCELLigence system) measuring γδ T cell lysis in real-time. Albeit in the 2 h end-point europium-TDA release assay no increased lysis was observed, in real-time xCELLigence assays both significant antibody-independent cytotoxicity and ADCC of γδ T cells were observed. The xCELLigence system outperformed the end-point europium-TDA release assay in sensitivity and allows drawing of conclusions to lysis kinetics of γδ T cells over prolonged periods of time periods. Combination of CD19 antibodies with primary as well as expanded γδ T cells exhibits a promising approach, which may enhance clinical outcome of patients with pediatric B-lineage ALL and requires clinical

  1. Response rate of fibrosarcoma cells to cytotoxic drugs on the expression level correlates to the therapeutic response rate of fibrosarcomas and is mediated by regulation of apoptotic pathways

    International Nuclear Information System (INIS)

    Because of the high resistance rate of fibrosarcomas against cytotoxic agents clinical chemotherapy of these tumors is not established. A better understanding of the diverse modes of tumor cell death following cytotoxic therapies will provide a molecular basis for new chemotherapeutic strategies. In this study we elucidated the response of a fibrosarcoma cell line to clinically used cytostatic agents on the level of gene expression. HT1080 fibrosarcoma cells were exposed to the chemotherapeutic agents doxorubicin, actinomycin D or vincristine. Total RNA was isolated and the gene expression patterns were analyzed by microarray analysis. Expression levels for 46 selected candidate genes were validated by quantitative real-time PCR. The analysis of the microarray data resulted in 3.309 (actinomycin D), 1.019 (doxorubicin) and 134 (vincristine) probesets that showed significant expression changes. For the RNA synthesis blocker actinomycin D, 99.4% of all differentially expressed probesets were under-represented. In comparison, probesets down-regulated by doxorubicin comprised only 37.4% of all genes effected by this agent. Closer analysis of the differentially regulated genes revealed that doxorubicin induced cell death of HT1080 fibrosarcoma cells mainly by regulating the abundance of factors mediating the mitochondrial (intrinsic) apoptosis pathway. Furthermore doxorubicin influences other pathways and crosstalk to other pathways (including to the death receptor pathway) at multiple levels. We found increased levels of cytochrome c, APAF-1 and members of the STAT-family (STAT1, STAT3), while Bcl-2 expression was decreased. Caspase-1, -3, -6, -8, and -9 were increased indicating that these proteases are key factors in the execution of doxorubicin mediated apoptosis. This study demonstrates that chemotherapy regulates the expression of apoptosis-related factors in fibrosarcoma cells. The number and the specific pattern of the genes depend on the used cytotoxic drug

  2. A murine model for study of anticryptococcal activity mediated by cytotoxic immune cells: Role in immunization and human vaccine strategies

    Directory of Open Access Journals (Sweden)

    Arsić-Arsenijević Valentina

    2011-01-01

    Full Text Available NK and T cells play a pivotal role in host defense to Cryptococcus neoformans (C. neoformans fungus which affects especially hosts with impaired cell mediated immunity. The vaccine against cryptococcosus is not developed yet, thus we established an animal BALB/c mice model to analyze anticryprococcal activity of immune cells. We detected that non-stimulated spleen mononuclear cells (MNC from non-immunized mice have the capacity to exhibit anticriptococcal activity on the incapsulated C. neoformans strain (ATCC 34873 and this activity can be enhanced by non-adherent cells (NAC. In order to obtained antigen-specific anticryprococcal activity, MNC and NAC were stimulated in vitro with corpuscular (Ag1 or soluble (Ag2 C. neoformans antigen prepared from the acapsular strain Cap67 (ATCC 52817. In vitro stimulation of immune cells with both C. neoformans antigens enhanced the anticryptococcal activity of MNC and NAC. NAC fraction expressed the highest anticryptococcal activity, also in the presence and in the absence of accessory cells (AC. The highest anticryptococcal activity of effector cells was detected after immunization of mice with the same C. neoformans antigens and after additional stimulation of immune cells in vitro with the some antigens. These data demonstrated that growth inhibition of C. neoformans mediated by mice effector cells can be enhanced with corpuscular, as well as soluble antigens. Thus designin an animal model which is simple and reproducible and can be used for further studies and development of immunization strategies against human cryptococcosis.

  3. Autophagy-independent enhancing effects of Beclin 1 on cytotoxicity of ovarian cancer cells mediated by proteasome inhibitors

    International Nuclear Information System (INIS)

    The ubiquitin-proteasome system and macroautophagy (hereafter referred to autophagy) are two complementary pathways for protein degradation. Emerging evidence suggests that proteasome inhibition might be a promising approach for tumor therapy. Accumulating data suggest that autophagy is activated as a compensatory mechanism upon proteasome activity is impaired. Autophagy activation was measured using acridine orange staining and LC3 transition. Cell viability and apoptosis were measured using MTT assay and flow cytometry, respectively. Beclin 1 expression vectors or shRNA against Beclin 1 (shBeclin 1) were transfected to investigate the role of Beclin 1 in autophagy activation and cytotoxicity of ovarian cancer cells induced by proteasome inhibitors. Proteasome inhibitors suppressed proliferation and induced autophagy in ovarian cancer cells. Neither phosphoinositide 3-kinase (PI3K) inhibitors nor shRNA against Beclin 1 could abolish the formation of acidic vacuoles and the processing of LC3 induced by proteasome inhibitors. Moreover, Beclin 1 overexpression enhanced anti-proliferative effects of proteasome inhibitors in ovarian cancer cells. For the first time, the current study demonstrated that proteasome inhibitors induced PI3K and Beclin 1-independent autophagy in ovarian cancer cells. In addition, this study revealed autophagy-independent tumor suppressive effects of Beclin 1 in ovarian cancer cells

  4. Suppressor T cells, distinct from "veto cells," are induced by alloantigen priming and mediate transferable suppression of cytotoxic T lymphocyte responses in vivo

    DEFF Research Database (Denmark)

    Owens, T; Crispe, I N

    1985-01-01

    Primary and secondary cytotoxic T lymphocyte responses to minor alloantigens can be suppressed by priming host mice with a high dose (10(8) cells) of alloantigenic donor spleen cells (SC). Such suppression is antigen specific and transferable into secondary hosts with T cells. One interpretation ...

  5. HLA-G1-transfected K562 cells do not inhibit NK-cell-mediated lysis in europium release cytotoxicity assay.

    Science.gov (United States)

    Sapak, M; Buc, M

    2003-01-01

    The class Ia of HLA molecules are recognised by NK-cells either by inhibitory or stimulatory NK-receptors. When inhibitory signals prevail over stimulatoryones, the target cells expressing the class Ia of HLA molecules are not lysed by NK-cells. Similarly, class Ib of HLA molecules have been reported to induce the inhibitory signal in NK-cells. The cell line K562 is deprived of both class Ia and class Ib of HLA molecules, respectively, the fact of which enhances the lysis of K562 cells when they are co-cultivated with NK-cells. To study the role of HLA-G molecules in NK-cell cytotoxic activity, HLA-G tranfected K562 cells were used as target cells. NK-cells were isolated from the peripheral blood of 4 unrelated persons using Miltenyi's Biotec isolation system. The purity of directly isolated NK cells (CD56 Multisort kit) was 74.1%, and that of indirectly isolated NK-cells (NK-cell isolation kit) 69.4%. The europium release cytotoxicity assay was used in all experiments. The percentage of cytotoxicity ranged from 19% to 24% when K562 target cells were used. Similar results were obtained with the HLA-G1-transfected target cells: the percentage of cytotoxicity ranged from 17% to 29%. Our preliminary results indicate that NK-cells are able to lyse both, K562 cells and the HLA-G1-transfected K562 cells. (Tab. 1, Fig. 8, Ref. 21.). PMID:15055728

  6. Inhibition of Grb2-mediated activation of MAPK signal transduction suppresses NOR1/CB1954-induced cytotoxicity in the HepG2 cell line.

    Science.gov (United States)

    Gui, Rong; Li, Dengqing; Qi, Guannan; Suhad, Ali; Nie, Xinmin

    2012-09-01

    The nitroreductase oxidored-nitro domain containing protein 1 (NOR1) gene may be involved in the chemical carcinogenesis of hepatic cancer and nasopharyngeal carcinoma (NPC). We have previously demonstrated that NOR1 overexpression is capable of converting the monofunctional alkylating agent 5-(aziridin-1-yl)-2,4-dinitrobenzamide (CB1954) into a toxic form by reducing the 4-nitro group of CB1954. Toxic CB1954 is able to enhance cell killing in the NPC cell line CNE1; however, the underlying mechanisms remain unknown. Using cDNA microarrays and quantitative real-time PCR, we previously discovered that NOR1 increases the expression of growth factor receptor-bound protein 2 (Grb2) mRNA by 4.8-fold in the human hepatocellular carcinoma cell line HepG2. In the present study, we revealed that NOR1 increased Grb2 protein expression by 3-fold in HepG2 cells. Additionally, we demonstrated that NOR1 enhanced CB1954-induced cell killing in HepG2 cells, and cell cytotoxicity was inhibited with the tyrosine kinase inhibitor genistein, or by stable transfection of Grb2 small hairpin RNA (shRNA) pU6(+27)-shGrb2 to silence the expression of Grb2. Western blot analysis revealed that Grb2 downregulation may reduce the activity of the mitogen-activated protein kinase (MAPK). Inhibiting the activation of MAPK using the methyl ethyl ketone (MEK) inhibtor PD98059 suppressed CB1954-induced cell killing. These results suggested that the NOR1 gene enhances CB1954-mediated cell cytotoxicity through the upregulation of Grb2 expression and the activation of MAPK signal transduction in the HepG2 cell line. PMID:23741254

  7. Synergistic enhancement of NK cell-mediated cytotoxicity by combination of histone deacetylase inhibitor and ionizing radiation

    International Nuclear Information System (INIS)

    The overexpression of histone deacetylase (HDAC) and a subsequent decrease in the acetylation levels of nuclear histones are frequently observed in cancer cells. Generally it was accepted that the deacetylation of histones suppressed expression of the attached genes. Therefore, it has been suggested that HDAC might contribute to the survival of cancer cells by altering the NKG2D ligands transcripts. By the way, the translational regulation of NKG2D ligands remaines unclear in cancer cells. It appears the modulation of this unclear mechanism could enhance NKG2D ligand expressions and the susceptibility of cancer cells to NK cells. Previously, it was reported that irradiation can increase the surface expressions of NKG2D ligands on several cancer cell types without increasing the levels of NKG2D ligand transcripts via ataxia telangiectasia mutated and ataxia telangiectasia and Rad3 related (ATM-ATR) pathway, and suggested that radiation therapy might be used to increase the translation of NKG2D ligands. Two NSCLC cell lines, that is, A549 and NCI-H23 cells, were used to investigate the combined effects of ionizing radiation and HDAC inhibitors on the expressions of five NKG2D ligands. The mRNA expressions of the NKG2D ligands were quantitated by multiplex reverse transcription-PCR. Surface protein expressions were measured by flow cytometry, and the susceptibilities of cancer cells to NK cells were assayed by time-resolved fluorometry using the DELFIA® EuTDA cytotoxicity kit and by flow cytometry. The expressions of NKG2D ligands were found to be regulated at the transcription and translation levels. Ionizing radiation and HDAC inhibitors in combination synergistically increased the expressions of NKG2D ligands. Furthermore, treatment with ATM-ATR inhibitors efficiently blocked the increased translations of NKG2D ligands induced by ionizing radiation but did not block the increased ligand translations induced by HDAC inhibitors. The study confirms that increased NKG

  8. Genetic control of cell-mediated lympholysis to trinitrophenyl (TNP)-modified murine syngeneic cells. Expression of Ir gene function at the cytotoxic precursor and helper cell

    International Nuclear Information System (INIS)

    The present study investigates some of the cellular mechanisms responsible for the defect in cytotoxic T lymphocyte (CTL) response to trinitrophenyl (TNP)-modified H-2/sup b/ self components in C57Bl/6(H-2/sup b/) or (C57BL/6 x C3H/He)(H-2/sup b/ x H-2/sup k/)F1 mice. C3H/He, C57BL/6, and (C57BL/6 x C3H/He)F1 mice were immunized to TNP-modified self by skin painting with trinitrochlorobenzene, and their spleen cells were used a) for in vitro secondary sensitization to syngeneic spleen cells conjugated with limiting concentrations of trinitrobenzene sulfonate (TNP-self) or b) as a source of radioresistant helper cells for augmenting the TNP-self CTL response generated by spleen cells from unimmunized C3H/He, C57Bl/6, and F1 mice. The results indicate that strong or weak in vitro secondary CTL responses could be obtained in the H-2/sup k/ or H-2/sup b/ strain, respectively. This strain-dependent genetic difference was also observed in (H-2/sup b/ x H-2/sup k/)F1 mice. These results permit the detection of the Ir gene defect in the anti-TNP-H-2/sup b/ self CTL response at both the helper and cytotoxic precursor cell levels

  9. Pili Binding to Asialo-GM1 on Epithelial Cells Can Mediate Cytotoxicity or Bacterial Internalization by Pseudomonas aeruginosa

    OpenAIRE

    Comolli, James C; Waite, Leslie L.; Keith E Mostov; Joanne N. Engel

    1999-01-01

    The interaction of Pseudomonas aeruginosa type IV pili and the glycosphingolipid asialo-GM1 (aGM1) can mediate bacterial adherence to epithelial cells, but the steps subsequent to this adherence have not been elucidated. To investigate the result of the interaction of pili and aGM1, we used polarized epithelial monolayers of Madin-Darby canine kidney (MDCK) cells in culture, which contained little detectable aGM1 on their apical surface but were able to incorporate exogenous aGM1. Compared to...

  10. Synergistic Cytotoxic Effect of Gold Nanoparticles and 5-Aminolevulinic Acid-Mediated Photodynamic Therapy against Skin Cancer Cells

    Directory of Open Access Journals (Sweden)

    Mahnaz Hadizadeh

    2014-09-01

    Full Text Available Background: Photodynamic therapy (PDT is a promising therapeutic modality for the treatment of cancer and other diseases. In this study, the epidermoid carcinoma cell line A431 and the normal fibroblasts were used to investigate whether gold nanoparticles (GNPs can induce an increase in cell death during PDT using 5-aminolevulinic acid (5-ALA as a photosensitizer. Methods: Human fibroblast and A431 cells were grown in 96-well plates. The effect of GNPs on the efficacy of 5-ALA-mediated PDT (5-ALA-PDT was evaluated by comparing the effect of 5-ALA with GNPs to the effect of 5-ALA alone. Cell viability was determined by the methyl- tetrazolium assay. Results: Dark toxicity experiments showed that 5-ALA at concentrations 0.5, 1 and 2 mM had no significant effect on cell viability of both cell lines. However, treatment of cells with 5-ALA (0.5 to 2 mM and light dose of 25 Jcm-2 led to 5-10% and 31-42% decrease in cell viability of fibroblast and A431 cells respectively. The data also shows that GNPs in both the absence and the presence of light, results in a dose-dependent decrease in cell viability of both cell lines. However, the sensitivity of cancer cells to GNPs at concentrations more than 24 μg/ml was approximately 2.5- to 4-fold greater than healthy cells. Furthermore, data indicates that 5-ALA in combination with GNPs results in a synergistic reduction in viability of A431 cells. Conclusion: In summary, the findings of this study suggest that concomitant treatment with 5-ALA and GNPs may be useful in enhancing the effect of 5-ALA-PDT.

  11. CYP3A5 mediates bioactivation and cytotoxicity of tetrandrine.

    Science.gov (United States)

    Tian, Ye; Shen, Shuijie; Jiang, Yan; Shen, Qi; Zeng, Su; Zheng, Jiang

    2016-07-01

    Tetrandrine is a diaryl ether-type bisbenzylisoquinoline alkaloid and has shown multiple pharmacological activities. Our early work demonstrated that tetrandrine produced acute pulmonary toxicity and that tetrandrine was biotransformed to a quinone methide-derived metabolite mediated by CYP3A enzymes. The formation of the reactive intermediate is suggested to be responsible for the pulmonary toxicity induced by tetrandrine. In the present study, a WI-38-based Cyp3a5 transgenic cell line (WI-38/Cyp3a5) was established to investigate the role of CYP3A5 in tetrandrine-induced cytotoxicity. The transgenic cells were found to be more susceptible to the cytotoxicity of tetrandrine than the wild-type cells (WI-38/Vector). WI-38/Cyp3a5 cells showed higher cellular ROS levels, higher LDH activities in culture media, but lower cellular GSH contents than those observed in WI-38/Vector cells after exposure to tetrandrine. And severer apoptosis were observed in WI-38/Cyp3a5 cells after treatment with tetrandrine: WI-38/Cyp3a5 cells had higher proportion of early and late apoptotic cells, higher expression levels of caspase-3, but lower level of Bcl-2 than WI-38/Vector cells. This study provided strong evidence that CYP3A5 participated in tetrandrine-induced cytotoxicity. PMID:26302866

  12. B Cells Are Critical to T-cell—Mediated Antitumor Immunity Induced by a Combined Immune-Stimulatory/Conditionally Cytotoxic Therapy for Glioblastoma

    Directory of Open Access Journals (Sweden)

    Marianela Candolfi

    2011-10-01

    Full Text Available We have demonstrated that modifying the tumor microenvironment through intratumoral administration of adenoviral vectors (Ad encoding the conditional cytotoxic molecule, i.e., HSV1-TK and the immune-stimulatory cytokine, i.e., fms-like tyrosine kinase 3 ligand (Flt3L leads to T-cell-dependent tumor regression in rodent models of glioblastoma. We investigated the role of B cells during immune-mediated glioblastoma multiforme regression. Although treatment with Ad-TK+Ad-Flt3L induced tumor regression in 60% of wild-type (WT mice, it completely failed in B-cell-deficient Igh6-/- mice. Tumor-specific T-cell precursors were detected in Ad-TK+Ad-Flt3L-treated WT mice but not in Igh6-/- mice. The treatment also failed in WT mice depleted of total B cells or marginal zone B cells. Because we could not detect circulating antibodies against tumor cells and the treatment was equally efficient in WT mice and in mice with B-cell-specific deletion of Prdm 1 (encoding Blimp-1, in which B cells are present but unable to fully differentiate into antibody-secreting plasma cells, tumor regression in this model is not dependent on B cells’ production of tumor antigen-specific immunoglobulins. Instead, B cells seem to play a role as antigen-presenting cells (APCs. Treatment with Ad-TK+Ad-Flt3L led to an increase in the number of B cells in the cervical lymph nodes, which stimulated the proliferation of syngeneic T cells and induced clonal expansion of antitumor T cells. Our data show that B cells act as APCs, playing a critical role in clonal expansion of tumor antigen-specific T cells and brain tumor regression.

  13. Rhein Elicits In Vitro Cytotoxicity in Primary Human Liver HL-7702 Cells by Inducing Apoptosis through Mitochondria-Mediated Pathway

    Directory of Open Access Journals (Sweden)

    Guy-Armel Bounda

    2015-01-01

    Full Text Available Objective. To study rhein-induced apoptosis signaling pathway and to investigate its molecular mechanisms in primary human hepatic cells. Results. Cell viability of HL-7702 cells treated with rhein showed significant decrease in dose-dependent manner. Following rhein treatment (25 μM, 50 μM, and 100 μM for 12 h, the detection of apoptotic cells was significantly analyzed by flow cytometry and nuclear morphological changes by Hoechst 33258, respectively. Fatty degeneration studies showed upregulation level of the relevant hepatic markers (P < 0.01. Caspase activities expressed significant upregulation of caspase-3, caspase-9, and caspase-8. Moreover, apoptotic cells by rhein were significantly inhibited by Z-LEHD-FMK and Z-DEVD-FMK, caspase-9 inhibitor, and caspase-3 inhibitor, respectively. Overproduction of reactive oxygen species, lipid peroxidation, and loss of mitochondrial membrane potential were detected by fluorometry. Additionally, NAC, a ROS scavenger, significantly attenuated rhein-induced oxidative damage in HL-7702 cells. Furthermore, real-time qPCR results showed significant upregulation of p53, PUMA, Apaf-1, and Casp-9 and Casp-3 mRNA, with no significant changes of Fas and Cytochrome-c. Immunoblotting revealed significant Cytochrome-c release from mitochondria into cytosol and no change in Fas expression. Conclusion. Taken together, these observations suggested that rhein could induce apoptosis in HL-7702 cells via mitochondria-mediated signal pathway with involvement of oxidative stress mechanism.

  14. Role of Zn doping in oxidative stress mediated cytotoxicity of TiO2 nanoparticles in human breast cancer MCF-7 cells

    Science.gov (United States)

    Ahamed, Maqusood; Khan, M. A. Majeed; Akhtar, Mohd Javed; Alhadlaq, Hisham A.; Alshamsan, Aws

    2016-07-01

    We investigated the effect of Zn-doping on structural and optical properties as well as cellular response of TiO2 nanoparticles (NPs) in human breast cancer MCF-7 cells. A library of Zn-doped (1–10 at wt%) TiO2 NPs was prepared. Characterization data indicated that dopant Zn was incorporated into the lattice of host TiO2. The average particle size of TiO2 NPs was decreases (38 to 28 nm) while the band gap energy was increases (3.35 eV–3.85 eV) with increasing the amount of Zn-doping. Cellular data demonstrated that Zn-doped TiO2 NPs induced cytotoxicity (cell viability reduction, membrane damage and cell cycle arrest) and oxidative stress (reactive oxygen species generation & glutathione depletion) in MCF-7 cells and toxic intensity was increases with increasing the concentration of Zn-doping. Molecular data revealed that Zn-doped TiO2 NPs induced the down-regulation of super oxide dismutase gene while the up-regulation of heme oxygenase-1 gene in MCF-7 cells. Cytotoxicity induced by Zn-doped TiO2 NPs was efficiently prevented by N-acetyl-cysteine suggesting that oxidative stress might be the primarily cause of toxicity. In conclusion, our data indicated that Zn-doping decreases the particle size and increases the band gap energy as well the oxidative stress-mediated toxicity of TiO2 NPs in MCF-7 cells.

  15. Role of Zn doping in oxidative stress mediated cytotoxicity of TiO2 nanoparticles in human breast cancer MCF-7 cells

    Science.gov (United States)

    Ahamed, Maqusood; Khan, M. A. Majeed; Akhtar, Mohd Javed; Alhadlaq, Hisham A.; Alshamsan, Aws

    2016-01-01

    We investigated the effect of Zn-doping on structural and optical properties as well as cellular response of TiO2 nanoparticles (NPs) in human breast cancer MCF-7 cells. A library of Zn-doped (1–10 at wt%) TiO2 NPs was prepared. Characterization data indicated that dopant Zn was incorporated into the lattice of host TiO2. The average particle size of TiO2 NPs was decreases (38 to 28 nm) while the band gap energy was increases (3.35 eV–3.85 eV) with increasing the amount of Zn-doping. Cellular data demonstrated that Zn-doped TiO2 NPs induced cytotoxicity (cell viability reduction, membrane damage and cell cycle arrest) and oxidative stress (reactive oxygen species generation & glutathione depletion) in MCF-7 cells and toxic intensity was increases with increasing the concentration of Zn-doping. Molecular data revealed that Zn-doped TiO2 NPs induced the down-regulation of super oxide dismutase gene while the up-regulation of heme oxygenase-1 gene in MCF-7 cells. Cytotoxicity induced by Zn-doped TiO2 NPs was efficiently prevented by N-acetyl-cysteine suggesting that oxidative stress might be the primarily cause of toxicity. In conclusion, our data indicated that Zn-doping decreases the particle size and increases the band gap energy as well the oxidative stress-mediated toxicity of TiO2 NPs in MCF-7 cells. PMID:27444578

  16. Helper cell-independent cytotoxic clones in man

    OpenAIRE

    1982-01-01

    We report here a class of helper cell-independent cytotoxic T cell (HITc) clones in man that can proliferate in response to antigenic stimulation as well as mediate cytotoxicity. HITc appear to be rare among clones derived from primary in vitro allosensitized culture, but constitute the majority of clones derived from cells sensitized to autologous Epstein-Barr virus-transformed lymphoblastoid cell lines. The implications of the derivation and function of HITc clones are discussed.

  17. Overcoming bortezomib resistance in human B cells by anti-CD20/rituximab-mediated complement-dependent cytotoxicity and epoxyketone-based irreversible proteasome inhibitors

    Directory of Open Access Journals (Sweden)

    Verbrugge Sue Ellen

    2013-01-01

    Full Text Available Abstract Background In clinical and experimental settings, antibody-based anti-CD20/rituximab and small molecule proteasome inhibitor (PI bortezomib (BTZ treatment proved effective modalities for B cell depletion in lymphoproliferative disorders as well as autoimmune diseases. However, the chronic nature of these diseases requires either prolonged or re-treatment, often with acquired resistance as a consequence. Methods Here we studied the molecular basis of acquired resistance to BTZ in JY human B lymphoblastic cells following prolonged exposure to this drug and examined possibilities to overcome resistance by next generation PIs and anti-CD20/rituximab-mediated complement-dependent cytotoxicity (CDC. Results Characterization of BTZ-resistant JY/BTZ cells compared to parental JY/WT cells revealed the following features: (a 10–12 fold resistance to BTZ associated with the acquisition of a mutation in the PSMB5 gene (encoding the constitutive β5 proteasome subunit introducing an amino acid substitution (Met45Ile in the BTZ-binding pocket, (b a significant 2–4 fold increase in the mRNA and protein levels of the constitutive β5 proteasome subunit along with unaltered immunoproteasome expression, (c full sensitivity to the irreversible epoxyketone-based PIs carfilzomib and (to a lesser extent the immunoproteasome inhibitor ONX 0914. Finally, in association with impaired ubiquitination and attenuated breakdown of CD20, JY/BTZ cells harbored a net 3-fold increase in CD20 cell surface expression, which was functionally implicated in conferring a significantly increased anti-CD20/rituximab-mediated CDC. Conclusions These results demonstrate that acquired resistance to BTZ in B cells can be overcome by next generation PIs and by anti-CD20/rituximab-induced CDC, thereby paving the way for salvage therapy in BTZ-resistant disease.

  18. Cytotoxic activity against human neuroblastoma and melanoma cells mediated by IgM antibodies derived from peripheral blood of healthy donors.

    Science.gov (United States)

    Devarapu, Satish Kumar; Mamidi, Srinivas; Plöger, Frank; Dill, Othmar; Blixt, Ola; Kirschfink, Michael; Schwartz-Albiez, Reinhard

    2016-06-15

    A small percentage of healthy donors identified in the Western population carry antibodies in their peripheral blood which convey cytotoxic activity against certain human melanoma and neuroblastoma cell lines. We measured the cytotoxic activity of sera and plasmas from healthy donors on the human neuroblastoma cell line Kelly and various melanoma cell lines. Antibodies of IgM isotype, presumably belonging to the class of naturally occurring antibodies, exerted cytotoxic activity in a complement-dependent fashion. Apart from complement-dependent tumor cell lysis, we observed C3 opsonization in all tumor cell lines upon treatment with cytotoxic plasmas. Cell lines tested primarily expressed membrane complement regulatory proteins (mCRP) CD46, CD55 and CD59 to various extents. Blocking of mCRPs by monoclonal antibodies enhanced cell lysis and opsonization, though some melanoma cells remained resistant to complement attack. Epitopes recognized by cytotoxic antibodies were represented by gangliosides such as GD2 and GD3, as evidenced by cellular sialidase pretreatment and enhanced expression of distinct gangliosides. It remains to be clarified why only a small fraction of healthy persons carry these antitumor cytotoxic antibodies. PMID:26830059

  19. The strong in vivo anti-tumor effect of the UIC2 monoclonal antibody is the combined result of Pgp inhibition and antibody dependent cell-mediated cytotoxicity.

    Directory of Open Access Journals (Sweden)

    Gábor Szalóki

    Full Text Available P-glycoprotein (Pgp extrudes a large variety of chemotherapeutic drugs from the cells, causing multidrug resistance (MDR. The UIC2 monoclonal antibody recognizes human Pgp and inhibits its drug transport activity. However, this inhibition is partial, since UIC2 binds only to 10-40% of cell surface Pgps, while the rest becomes accessible to this antibody only in the presence of certain substrates or modulators (e.g. cyclosporine A (CsA. The combined addition of UIC2 and 10 times lower concentrations of CsA than what is necessary for Pgp inhibition when the modulator is applied alone, decreased the EC50 of doxorubicin (DOX in KB-V1 (Pgp+ cells in vitro almost to the level of KB-3-1 (Pgp- cells. At the same time, UIC2 alone did not affect the EC50 value of DOX significantly. In xenotransplanted severe combined immunodeficient (SCID mice co-treated with DOX, UIC2 and CsA, the average weight of Pgp+ tumors was only ∼10% of the untreated control and in 52% of these animals we could not detect tumors at all, while DOX treatment alone did not decrease the weight of Pgp+ tumors. These data were confirmed by visualizing the tumors in vivo by positron emission tomography (PET based on their increased 18FDG accumulation. Unexpectedly, UIC2+DOX treatment also decreased the size of tumors compared to the DOX only treated animals, as opposed to the results of our in vitro cytotoxicity assays, suggesting that immunological factors are also involved in the antitumor effect of in vivo UIC2 treatment. Since UIC2 binding itself did not affect the viability of Pgp expressing cells, but it triggered in vitro cell killing by peripheral blood mononuclear cells (PBMCs, it is concluded that the impressive in vivo anti-tumor effect of the DOX-UIC2-CsA treatment is the combined result of Pgp inhibition and antibody dependent cell-mediated cytotoxicity (ADCC.

  20. The strong in vivo anti-tumor effect of the UIC2 monoclonal antibody is the combined result of Pgp inhibition and antibody dependent cell-mediated cytotoxicity.

    Science.gov (United States)

    Szalóki, Gábor; Krasznai, Zoárd T; Tóth, Ágnes; Vízkeleti, Laura; Szöllősi, Attila G; Trencsényi, György; Lajtos, Imre; Juhász, István; Krasznai, Zoltán; Márián, Teréz; Balázs, Margit; Szabó, Gábor; Goda, Katalin

    2014-01-01

    P-glycoprotein (Pgp) extrudes a large variety of chemotherapeutic drugs from the cells, causing multidrug resistance (MDR). The UIC2 monoclonal antibody recognizes human Pgp and inhibits its drug transport activity. However, this inhibition is partial, since UIC2 binds only to 10-40% of cell surface Pgps, while the rest becomes accessible to this antibody only in the presence of certain substrates or modulators (e.g. cyclosporine A (CsA)). The combined addition of UIC2 and 10 times lower concentrations of CsA than what is necessary for Pgp inhibition when the modulator is applied alone, decreased the EC50 of doxorubicin (DOX) in KB-V1 (Pgp+) cells in vitro almost to the level of KB-3-1 (Pgp-) cells. At the same time, UIC2 alone did not affect the EC50 value of DOX significantly. In xenotransplanted severe combined immunodeficient (SCID) mice co-treated with DOX, UIC2 and CsA, the average weight of Pgp+ tumors was only ∼10% of the untreated control and in 52% of these animals we could not detect tumors at all, while DOX treatment alone did not decrease the weight of Pgp+ tumors. These data were confirmed by visualizing the tumors in vivo by positron emission tomography (PET) based on their increased 18FDG accumulation. Unexpectedly, UIC2+DOX treatment also decreased the size of tumors compared to the DOX only treated animals, as opposed to the results of our in vitro cytotoxicity assays, suggesting that immunological factors are also involved in the antitumor effect of in vivo UIC2 treatment. Since UIC2 binding itself did not affect the viability of Pgp expressing cells, but it triggered in vitro cell killing by peripheral blood mononuclear cells (PBMCs), it is concluded that the impressive in vivo anti-tumor effect of the DOX-UIC2-CsA treatment is the combined result of Pgp inhibition and antibody dependent cell-mediated cytotoxicity (ADCC). PMID:25238617

  1. Curcumin enhances the mitomycin C-induced cytotoxicity via downregulation of MKK1/2-ERK1/2-mediated Rad51 expression in non-small cell lung cancer cells

    International Nuclear Information System (INIS)

    Curcumin (diferuloylmethane), a major active component of turmeric (Curcuma longa), has been reported to suppress the proliferation of a wide variety of tumor cells. Rad51 is a key protein in the homologous recombination (HR) pathway of DNA double-strand break repair, and HR represents a novel target for cancer therapy. A high expression of Rad51 has been reported in chemo- or radio-resistant carcinomas. Therefore, in the current study, we will examine whether curcumin could enhance the effects of mitomycin C (MMC), a DNA interstrand cross-linking agent, to induce cytotoxicity by decreasing Rad51 expression. Exposure of two human non-small lung cancer (NSCLC) cell lines (A549 and H1975) to curcumin could suppress MMC-induced MKK1/2-ERK1/2 signal activation and Rad51 protein expression. Enhancement of ERK1/2 activation by constitutively active MKK1/2 (MKK1/2-CA) increased Rad51 protein levels in curcumin and MMC co-treated human lung cells. Moreover, the synergistic cytotoxic effect induced by curcumin combined with MMC was decreased by MKK1-CA-mediated enhancement of ERK1/2 activation by a significant degree. In contrast, MKK1/2 inhibitor, U0126 was shown to augment the cytotoxicity of curcumin and MMC through downregulation of ERK1/2 activation and Rad51 expression. Depletion of endogenous Rad51 expression by siRad51 RNA transfection significantly enhanced MMC and/or curcumin induced cell death and cell growth inhibition. In contrast, an overexpression of Rad51 protected lung cancer cells from synergistic cytotoxic effects induced by curcumin and MMC. We concluded that Rad51 inhibition may be an additional action mechanism for enhancing the chemosensitization of MMC by curcumin in NSCLC. - Highlights: → Curcumin downregulates MKK-ERK-mediated Rad51 expression. → Curcumin enhances mitomycin C-induced cytotoxicity. → Rad51 protects cells from cytotoxic effects induced by curcumin and mitomycin C. → Rad51 inhibition enhances the chemosensitization of

  2. Down-regulation of ERK1/2 and AKT-mediated X-ray repair cross-complement group 1 protein (XRCC1) expression by Hsp90 inhibition enhances the gefitinib-induced cytotoxicity in human lung cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Tung, Chun-Liang [Department of Pathology, Ditmanson Medical Foundation Chia-Yi Christian Hospital, Chiayi, Taiwan (China); Jian, Yi-Jun [Department of Pathology, Ditmanson Medical Foundation Chia-Yi Christian Hospital, Chiayi, Taiwan (China); Department of Biochemical Science and Technology, National Chiayi University, 300 Syuefu Road, Chiayi 600, Taiwan (China); Syu, Jhan-Jhang; Wang, Tai-Jing; Chang, Po-Yuan; Chen, Chien-Yu; Jian, Yun-Ting [Department of Biochemical Science and Technology, National Chiayi University, 300 Syuefu Road, Chiayi 600, Taiwan (China); Lin, Yun-Wei, E-mail: linyw@mail.ncyu.edu.tw [Department of Biochemical Science and Technology, National Chiayi University, 300 Syuefu Road, Chiayi 600, Taiwan (China)

    2015-05-15

    Gefitinib (Iressa{sup R}, ZD1839) is a selective epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) that blocks growth factor-mediated cell proliferation and extracellular signal-regulated kinases 1/2 (ERK1/2) and AKT signaling activation. It has been shown that inhibition of Hsp90 function can enhance antitumor activity of EGFR-TKI. XRCC1 is an important scaffold protein in base excision repair, which could be regulated by ERK1/2 and AKT pathways. However, the role of ERK1/2 and AKT-mediated XRCC1 expression in gefitinib alone or combination with an Hsp90 inhibitor-induced cytotoxicity in non-small cell lung cancer (NSCLC) cells has not been identified. In this study, gefitinib treatment decreased XRCC1 mRNA and protein expression through ERK1/2 and AKT inactivation in two NSCLC cells, A549 and H1975. Knocking down XRCC1 expression by transfection with small interfering RNA of XRCC1 enhanced the cytotoxicity and cell growth inhibition of gefitinib. Combining treatment of gefitinib with an Hsp90 inhibitor resulted in enhancing the reduction of XRCC1 protein and mRNA levels in gefitinib-exposed A549 and H1975 cells. Compared to a single agent alone, gefitinib combined with an Hsp90 inhibitor resulted in cytotoxicity and cell growth inhibition synergistically in NSCLC cells. Furthermore, transfection with constitutive active MKK1 or AKT vectors rescued the XRCC1 protein level as well as the cell survival suppressed by an Hsp90 inhibitor and gefitinib. These findings suggested that down-regulation of XRCC1 can enhance the sensitivity of gefitinib for NSCLC cells. - Highlights: • Gefitinib treatment decreased XRCC1 mRNA and protein expression in NSCLC cells. • Knocking down XRCC1 expression enhanced the cytotoxic effect of gefitinib. • Gefitinib combined with an Hsp90 inhibitor resulted in synergistically cytotoxicity.

  3. Down-regulation of ERK1/2 and AKT-mediated X-ray repair cross-complement group 1 protein (XRCC1) expression by Hsp90 inhibition enhances the gefitinib-induced cytotoxicity in human lung cancer cells

    International Nuclear Information System (INIS)

    Gefitinib (IressaR, ZD1839) is a selective epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) that blocks growth factor-mediated cell proliferation and extracellular signal-regulated kinases 1/2 (ERK1/2) and AKT signaling activation. It has been shown that inhibition of Hsp90 function can enhance antitumor activity of EGFR-TKI. XRCC1 is an important scaffold protein in base excision repair, which could be regulated by ERK1/2 and AKT pathways. However, the role of ERK1/2 and AKT-mediated XRCC1 expression in gefitinib alone or combination with an Hsp90 inhibitor-induced cytotoxicity in non-small cell lung cancer (NSCLC) cells has not been identified. In this study, gefitinib treatment decreased XRCC1 mRNA and protein expression through ERK1/2 and AKT inactivation in two NSCLC cells, A549 and H1975. Knocking down XRCC1 expression by transfection with small interfering RNA of XRCC1 enhanced the cytotoxicity and cell growth inhibition of gefitinib. Combining treatment of gefitinib with an Hsp90 inhibitor resulted in enhancing the reduction of XRCC1 protein and mRNA levels in gefitinib-exposed A549 and H1975 cells. Compared to a single agent alone, gefitinib combined with an Hsp90 inhibitor resulted in cytotoxicity and cell growth inhibition synergistically in NSCLC cells. Furthermore, transfection with constitutive active MKK1 or AKT vectors rescued the XRCC1 protein level as well as the cell survival suppressed by an Hsp90 inhibitor and gefitinib. These findings suggested that down-regulation of XRCC1 can enhance the sensitivity of gefitinib for NSCLC cells. - Highlights: • Gefitinib treatment decreased XRCC1 mRNA and protein expression in NSCLC cells. • Knocking down XRCC1 expression enhanced the cytotoxic effect of gefitinib. • Gefitinib combined with an Hsp90 inhibitor resulted in synergistically cytotoxicity

  4. Lymphocyte-mediated immune cytotoxicity in dogs infected with virulent canine distemper virus.

    OpenAIRE

    Appel, M J; Shek, W R; Summers, B.A.

    1982-01-01

    Immune lymphocyte-mediated cytotoxicity (ILMC) was evaluated in dogs after intranasal exposure to one of the following three virulent strains of canine distemper virus: Cornell A75/17, Ohio R252, and Snyder Hill. Cytotoxicity was tested with peripheral blood lymphocytes as effector cells and primary dog testicle cells that were matched for histocompatibility as target cells. A strong correlation was found between ILMC and the course of the infection. Dogs that succumbed to encephalitis with a...

  5. Amphipathic silica nanoparticles induce cytotoxicity through oxidative stress mediated and p53 dependent apoptosis pathway in human liver cell line HL-7702 and rat liver cell line BRL-3A.

    Science.gov (United States)

    Zuo, Daiying; Duan, Zhenfang; Jia, Yuanyuan; Chu, Tianxue; He, Qiong; Yuan, Juan; Dai, Wei; Li, Zengqiang; Xing, Liguo; Wu, Yingliang

    2016-09-01

    The aim of this study was to evaluate the potential cytotoxicity and the underlying mechanism of amphipathic silica nanoparticles (SiO2 NPs) exposure to human normal liver HL-7702 cells and rat normal liver BRL-3A cells. Prior to the cellular studies, transmission electron microscopy (TEM), dynamic light scattering (DLS), and X ray diffraction (XRD) were used to characterize SiO2 NPs, which proved the amorphous nature of SiO2 NPs with TEM diameter of 19.8±2.7nm. Further studies proved that exposure to SiO2 NPs dose-dependently induced cytotoxicity as revealed by cell counting kit (CCK-8) and lactate dehydrogenase (LDH) assays, with more severe cytotoxicity in HL-7702 cells than BRL-3A cells. Reactive oxygen species (ROS) and glutathione (GSH) assays showed elevated oxidative stress in both cells. Morphological studies by microscopic observation, Hochest 33258 and AO/EB staining indicated significant apoptotic changes after the cells being exposed to SiO2 NPs. Further studies by western blot indicated that SiO2 NPs exposure to both cells up-regulated p53, Bax and cleaved caspase-3 expression and down-regulated Bcl-2 and caspase-3 levels. Activated caspase-3 activity detected by colorimetric assay kit and caspase-3/7 activity detected by fluorescent real-time detection kit were significantly increased by SiO2 NPs exposure. In addition, antioxidant vitamin C significantly attenuated SiO2 NPs-induced caspase-3 activation, which indicated that SiO2 NPs-induced oxidative stress was involved in the process of HL-7702 and BRL-3A cell apoptosis. Taken together, these results suggested that SiO2 NPs-induced cytotoxicity in HL-7702 and BRL-3A cells was through oxidative stress mediated and p53, caspase-3 and Bax/Bcl-2 dependent pathway and HL-7702 cells were more sensitive to SiO2 NPs-induced cytotoxicity than BRL-3A cells. PMID:27187187

  6. A Lectin from Chinese Mistletoe Increases γδ T Cell-mediated Cytotoxicity through Induction of Caspase-dependent Apoptosis

    Institute of Scientific and Technical Information of China (English)

    Fang GONG; Dongqing ZHANG; Yanhui MA; Anlun MA; Qiwen YU; Jiying ZHANG; Hong NIE; Xuehua CHEN; Baihua SHEN; Ningli LI

    2007-01-01

    In this study, a mistletoe lectin (ML) was purified from Chinese mistletoe and the effect of this 60 kDa Chinese ML on human γδ T cell cytotoxicity, apoptosis and modulation of the cytokine network was studied. The cytotoxic properties of δ T cells was evaluated by using a 51Cr release test and employed fluorescence-activated cell sorting and enzyme-linked immunosorbent assay analysis to quantify translocation of the cell membrane phospholipid, phosphatidylserine and nuclear DNA fragmentation during apoptosis.It was found that: (i) ML effectively stimulated γδ T cell proliferation in a dose- and time-dependent manner;(ii) ML increased γδ T cell cytotoxicity; (iii) ML could modulate lipopolysaccharide-induced cytokine release in a pro-inflammatory manner by increasing tumor necrosis factor (TNF)-α release and inhibiting the release of anti-inflammatory interleukin (IL)-10; (iv) ML induced apoptosis in caspase-dependent and CD95-independent manner. The results indicated that ML is a potent immunomodulator to human γδ T cell cytotoxicity, apoptosis and cytokine production.

  7. Cell-mediated immunity to Plasmodium falciparum infection: evidence against the involvement of cytotoxic lymphocytes

    DEFF Research Database (Denmark)

    Theander, T G; Andersen, B J; Pedersen, B K;

    1988-01-01

    Blood mononuclear cells (PBMC) recognizing soluble malaria antigens (SPag) are present in the peripheral blood of individuals clinically immune to malaria, and they proliferate after exposure to such antigens. To test whether these cells have effector activity against Plasmodium falciparum, we...

  8. CERT depletion predicts chemotherapy benefit and mediates cytotoxic and polyploid‐specific cancer cell death through autophagy induction

    DEFF Research Database (Denmark)

    Lee, Alvin J. X.; Roylance, Rebecca; Sander, Jil;

    2012-01-01

    . Live cell microscopy analysis revealed that CERT depletion induces LAMP2‐dependent death of polyploid cells following exit from mitosis in the presence of paclitaxel. We find that CERT is relatively over‐expressed in HER2+ breast cancer and CERT protein expression acts as an independent prognostic...

  9. Size-mediated cytotoxicity of nanocrystalline titanium dioxide, pure and zinc-doped hydroxyapatite nanoparticles in human hepatoma cells

    International Nuclear Information System (INIS)

    Nanoparticles are highly used in biological applications including nanomedicine. In this present study, the interaction of HepG2 hepatocellular carcinoma cells (HCC) with hydroxyapatite (HAp), zinc-doped hydroxyapatite, and titanium dioxide (TiO2) nanoparticles were investigated. Hydroxyapatite, zinc-doped hydroxyapatite and titanium dioxide nanoparticles were prepared by wet precipitation method. They were subjected to isochronal annealing at different temperatures. Particle morphology and size distribution were characterized by X-ray diffraction and transmission electron microscope. The nanoparticles were co-cultured with HepG2 cells. MTT assay was employed to evaluate the proliferation of tumor cells. The DNA damaging effect of HAp, Zn-doped HAp, and TiO2 nanoparticles in human hepatoma cells (HepG2) were evaluated using DNA fragmentation studies. The results showed that in HepG2 cells, the anti-tumor activity strongly depend on the size of nanoparticles in HCC cells. Cell cycle arrest analysis for HAp, zinc-doped HAp, and TiO2 nanoparticles revealed the influence of HAp, zinc-doped HAp, and titanium dioxide nanoparticles on the apoptosis of HepG2 cells. The results imply that the novel nano nature effect plays an important role in the biomedicinal application of nanoparticles.

  10. Cytotoxicity of proparacaine to human corneal endothelial cells in vitro.

    Science.gov (United States)

    Wen, Qian; Fan, Tingjun; Bai, Suran; Sui, Yunlong

    2015-08-01

    Proparacaine is a widely used topical anesthetic in ophthalmic optometry and surgery, and has been reported to have cytotoxic effects on rabbit corneal endothelial cells after prolonged and repeated usage. Since rabbit is an exceptive mammal whose corneal endothelial cells still maintaining proliferation abilities even in adulthood, whether proparacaine has cytotoxic effects on human corneal endothelial (HCE) cells need to be further verified. Our objectives in the present study were to investigate the cytotoxicity to HCE cells of proparacaine and its underlying mechanisms in vitro and verify the cytotoxicity using cat corneal endothelial (CCE) cells in an in vivo model of cat corneas. Cytotoxic evaluation results indicated that a dose- and time-dependent toxic response of HCE cells to proparacaine over 0.03125% was rated based on morphology and viability, and a toxic response of CCE cells to 0.5% (clinical applied dosage) proparacaine was also rated based on cell density and histology. Importantly, treatment with proparacaine resulted in significant elevation of plasma membrane permeability, cell cycle arrest at S phase, fragmentation of genomic DNA, formation of apoptotic bodies, and externalization of phosphatidylserine (PS) of HCE cells. Moreover, proparacaine demonstrated disrupting effects on mitochondrial transmembrane potential (MTP) of HCE cells and activating effects on caspase-3, -8 and -9. This study demonstrates that proparacaine has notable cytotoxicity to both HCE cells in vitro and CCE cells in vivo, and its dose- and time-dependent cytotoxicity to HCE cells is achieved by inducing apoptosis via a mitochondrion-mediated caspase-dependent pathway. These findings provide new insights into the cytotoxicity and apoptosis-inducing effect of local anesthetics which should be used with great caution in the eye clinic. PMID:26165639

  11. Antibody penetration into living cells. V. Interference between two fc gamma receptor-mediated functions: antibody penetration and antibody-dependent cellular cytotoxicity.

    Science.gov (United States)

    Llerena, J M; Ruíz-Argüelles, A; Alarcón-Segovia, D; Llorente, L; Díaz-Jouanen, E

    1981-01-01

    The same Fc gamma receptor appears to be shared for two important phenomena: antibody-dependent cellular cytotoxicity (ADCC) and antibody penetration into living cells. ADCC is inhibited through interaction with the Fc gamma receptor during the antibody penetration process, indicating that both mechanisms may modulate each other in vitro. PMID:6972908

  12. Abrogation of Chk1-mediated S/G2 checkpoint by UCN-01 enhances ara-C-induced cytotoxicity in human colon cancer cells

    Institute of Scientific and Technical Information of China (English)

    Rong-guang SHAO; Chun-Xia CAO; Yves POMMIER

    2004-01-01

    AIM: To investigate whether 7-hydroxystaurosporine (UCN-01) affects cell cycle progression in arabinosylcytosine (ara-C) treated human colon carcinoma HT-29 cells. METHODS: Cytotoxicity, DNA synthesis, cell cycle distribution,protein level, and kinase activity were determined by clonogenic assay, flow cytometry, DNA synthesis assay,immunoblotting, and kinase assays, respectively. RESULTS: UCN-01 abrogated an S/G2-phase checkpoint in HT29 cells treated with ara-C. When UCN-01 was added after treatment with ara-C, the rate of recovery of DNA synthesis was enhanced and colony-forming ability diminished. Thus, premature recovery of DNA synthesis was associated with increased cytotoxicity. Measurements of cyclin A and B protein levels, Cdk2 and Cdc2 kinase activities, Cdc25C phosphorylation, and Chkl kinase activity were consistent with UCN-01-induced abrogation of the S/G2-phase checkpoint in ara-C treated cells. CONCLUSION: The abrogation of the S/G2 checkpoint may be due to inhibition of Chkl kinase by UCN-01. The enhanced cytotoxicity produced when UCN-01 was combined with ara-C suggested a rationale for the use of this drug combination for tumors that might be susceptible to cell cycle checkpoint abrogation.

  13. Aluminum doping tunes band gap energy level as well as oxidative stress-mediated cytotoxicity of ZnO nanoparticles in MCF-7 cells

    Science.gov (United States)

    Akhtar, Mohd Javed; Alhadlaq, Hisham A.; Alshamsan, Aws; Majeed Khan, M. A.; Ahamed, Maqusood

    2015-09-01

    We investigated whether Aluminum (Al) doping tunes band gap energy level as well as selective cytotoxicity of ZnO nanoparticles in human breast cancer cells (MCF-7). Pure and Al-doped ZnO nanoparticles were prepared by a simple sol-gel method. Characterization study confirmed the formation of single phase of AlxZn1-xO nanocrystals with the size range of 33-55 nm. Al-doping increased the band gap energy of ZnO nanoparticles (from 3.51 eV for pure to 3.87 eV for Al-doped ZnO). Al-doping also enhanced the cytotoxicity and oxidative stress response of ZnO nanoparticles in MCF-7 cells. The IC50 for undoped ZnO nanoparticles was 44 μg/ml while for the Al-doped ZnO counterparts was 31 μg/ml. Up-regulation of apoptotic genes (e.g. p53, bax/bcl2 ratio, caspase-3 & caspase-9) along with loss of mitochondrial membrane potential suggested that Al-doped ZnO nanoparticles induced apoptosis in MCF-7 cells through mitochondrial pathway. Importantly, Al-doping did not change the benign nature of ZnO nanoparticles towards normal cells suggesting that Al-doping improves the selective cytotoxicity of ZnO nanoparticles toward MCF-7 cells without affecting the normal cells. Our results indicated a novel approach through which the inherent selective cytotoxicity of ZnO nanoparticles against cancer cells can be further improved.

  14. Up-regulation of early growth response gene 1 (EGR-1) via ERK1/2 signals attenuates sulindac sulfide-mediated cytotoxicity in the human intestinal epithelial cells

    International Nuclear Information System (INIS)

    Non-steroidal anti-inflammatory drugs (NSAIDs) are used to relieve pain and inflammation and have also received considerable attention because of their preventive effects against human cancer. However, the drug application is sometimes limited by the severe gastrointestinal ulcers and mucosal complications. In the present study, NSAID sulindac sulfide was investigated for the cytotoxic injury in the intestinal epithelial cells in association with an immediate inducible factor, early growth response gene 1 (EGR-1). Previously we reported that sulindac sulfide can suppress tumor cell invasion by inducing EGR-1. Extending the previous study, EGR-1 induction by sulindac sulfide was observed both in the non-transformed and transformed human intestinal epithelial cell lines. In terms of signaling pathway, ERK1/2 MAP kinases and its substrate Elk-1 transcription factor were involved in the sulindac sulfide-induced EGR-1 gene expression. Moreover, sulindac sulfide stimulated the nuclear translocation of the transcription factor EGR-1, which was also mediated by ERK1/2 signaling pathway. The roles of EGR-1 signals in the apoptotic cell death were assessed in the intestinal epithelial cells. Suppression of EGR-1 expression retarded cellular growth and colony forming activity in the intestinal epithelial cells. Moreover, induced EGR-1 ameliorated sulindac sulfide-mediated apoptotic cell death and enhanced the cellular survival. Taken all together, sulindac sulfide activated ERK1/2 MAP kinases which then mediated EGR-1 induction and nuclear translocation, all of which played important roles in the cellular survival from NSAID-mediated cytotoxicity in the human intestinal epithelial cells, implicating the protective roles of EGR-1 in the NSAID-mediated mucosal injuries

  15. Escape of HIV-1-infected dendritic cells from TRAIL-mediated NK cell cytotoxicity during NK-DC cross-talk--a pivotal role of HMGB1.

    Directory of Open Access Journals (Sweden)

    Marie-Thérèse Melki

    2010-04-01

    Full Text Available Early stages of Human Immunodeficiency Virus-1 (HIV-1 infection are associated with local recruitment and activation of important effectors of innate immunity, i.e. natural killer (NK cells and dendritic cells (DCs. Immature DCs (iDCs capture HIV-1 through specific receptors and can disseminate the infection to lymphoid tissues following their migration, which is associated to a maturation process. This process is dependent on NK cells, whose role is to keep in check the quality and the quantity of DCs undergoing maturation. If DC maturation is inappropriate, NK cells will kill them ("editing process" at sites of tissue inflammation, thus optimizing the adaptive immunity. In the context of a viral infection, NK-dependent killing of infected-DCs is a crucial event required for early elimination of infected target cells. Here, we report that NK-mediated editing of iDCs is impaired if DCs are infected with HIV-1. We first addressed the question of the mechanisms involved in iDC editing, and we show that cognate NK-iDC interaction triggers apoptosis via the TNF-related apoptosis-inducing ligand (TRAIL-Death Receptor 4 (DR4 pathway and not via the perforin pathway. Nevertheless, once infected with HIV-1, DC(HIV become resistant to NK-induced TRAIL-mediated apoptosis. This resistance occurs despite normal amounts of TRAIL released by NK cells and comparable DR4 expression on DC(HIV. The escape of DC(HIV from NK killing is due to the upregulation of two anti-apoptotic molecules, the cellular-Flice like inhibitory protein (c-FLIP and the cellular inhibitor of apoptosis 2 (c-IAP2, induced by NK-DC(HIV cognate interaction. High-mobility group box 1 (HMGB1, an alarmin and a key mediator of NK-DC cross-talk, was found to play a pivotal role in NK-dependent upregulation of c-FLIP and c-IAP2 in DC(HIV. Finally, we demonstrate that restoration of DC(HIV susceptibility to NK-induced TRAIL killing can be obtained either by silencing c-FLIP and c-IAP2 by specific

  16. 5-Azacytidine treatment sensitizes tumor cells to T-cell mediated cytotoxicity and modulates NK cells in patients with myeloid malignancies.

    Science.gov (United States)

    Gang, A O; Frøsig, T M; Brimnes, M K; Lyngaa, R; Treppendahl, M B; Grønbæk, K; Dufva, I H; Straten, P Thor; Hadrup, S R

    2014-01-01

    Treatment with the demethylating agent 5-Azacytidine leads to prolonged survival for patients with myelodysplastic syndrome, and the demethylation induces upregulation of cancer-testis antigens. Cancer-testis antigens are well-known targets for immune recognition in cancer, and the immune system may have a role in this treatment regimen. We show here that 5-Azacytidine treatment leads to increased T-cell recognition of tumor cells. T-cell responses against a large panel of cancer-testis antigens were detected before treatment, and these responses were further induced upon initiation of treatment. These characteristics point to an ideal combination of 5-Azacytidine and immune therapy to preferentially boost T-cell responses against cancer-testis antigens. To initiate such combination therapy, essential knowledge is required about the general immune modulatory effect of 5-Azacytidine. We therefore examined potential treatment effects on both immune stimulatory (CD8 and CD4 T cells and Natural Killer (NK) cells) and immune inhibitory cell subsets (myeloid-derived suppressor cells and regulatory T cells). We observed a minor decrease and modulation of NK cells, but for all other populations no effects could be detected. Together, these data support a strategy for combining 5-Azacytidine treatment with immune therapy for potential clinical benefit. PMID:24681961

  17. 5-Azacytidine treatment sensitizes tumor cells to T-cell mediated cytotoxicity and modulates NK cells in patients with myeloid malignancies

    Science.gov (United States)

    Gang, A O; Frøsig, T M; Brimnes, M K; Lyngaa, R; Treppendahl, M B; Grønbæk, K; Dufva, I H; Straten, P thor; Hadrup, S R

    2014-01-01

    Treatment with the demethylating agent 5-Azacytidine leads to prolonged survival for patients with myelodysplastic syndrome, and the demethylation induces upregulation of cancer-testis antigens. Cancer-testis antigens are well-known targets for immune recognition in cancer, and the immune system may have a role in this treatment regimen. We show here that 5-Azacytidine treatment leads to increased T-cell recognition of tumor cells. T-cell responses against a large panel of cancer-testis antigens were detected before treatment, and these responses were further induced upon initiation of treatment. These characteristics point to an ideal combination of 5-Azacytidine and immune therapy to preferentially boost T-cell responses against cancer-testis antigens. To initiate such combination therapy, essential knowledge is required about the general immune modulatory effect of 5-Azacytidine. We therefore examined potential treatment effects on both immune stimulatory (CD8 and CD4 T cells and Natural Killer (NK) cells) and immune inhibitory cell subsets (myeloid-derived suppressor cells and regulatory T cells). We observed a minor decrease and modulation of NK cells, but for all other populations no effects could be detected. Together, these data support a strategy for combining 5-Azacytidine treatment with immune therapy for potential clinical benefit. PMID:24681961

  18. 5-Azacytidine treatment sensitizes tumor cells to T-cell mediated cytotoxicity and modulates NK cells in patients with myeloid malignancies

    OpenAIRE

    Gang, A O; Frøsig, T M; Brimnes, M K; Lyngaa, R; Treppendahl, M B; Grønbæk, K; Dufva, I H; Straten, P thor; Hadrup, S R

    2014-01-01

    Treatment with the demethylating agent 5-Azacytidine leads to prolonged survival for patients with myelodysplastic syndrome, and the demethylation induces upregulation of cancer-testis antigens. Cancer-testis antigens are well-known targets for immune recognition in cancer, and the immune system may have a role in this treatment regimen. We show here that 5-Azacytidine treatment leads to increased T-cell recognition of tumor cells. T-cell responses against a large panel of cancer-testis antig...

  19. 5-Azacytidine treatment sensitizes tumor cells to T-cell mediated cytotoxicity and modulates NK cells in patients with myeloid malignancies

    DEFF Research Database (Denmark)

    Gang, A O; Frøsig, T M; Brimnes, M K;

    2014-01-01

    Treatment with the demethylating agent 5-Azacytidine leads to prolonged survival for patients with myelodysplastic syndrome, and the demethylation induces upregulation of cancer-testis antigens. Cancer-testis antigens are well-known targets for immune recognition in cancer, and the immune system...... may have a role in this treatment regimen. We show here that 5-Azacytidine treatment leads to increased T-cell recognition of tumor cells. T-cell responses against a large panel of cancer-testis antigens were detected before treatment, and these responses were further induced upon initiation of...... treatment. These characteristics point to an ideal combination of 5-Azacytidine and immune therapy to preferentially boost T-cell responses against cancer-testis antigens. To initiate such combination therapy, essential knowledge is required about the general immune modulatory effect of 5-Azacytidine. We...

  20. Cytotoxicity of VEGF121/rGel on vascular endothelial cells resulting in inhibition of angiogenesis is mediated via VEGFR-2

    Directory of Open Access Journals (Sweden)

    Hittelman Walter N

    2011-08-01

    Full Text Available Abstract Background The fusion protein VEGF121/rGel composed of the growth factor VEGF121 and the plant toxin gelonin targets the tumor neovasculature and exerts impressive anti-vascular effects. We have previously shown that VEGF121/rGel is cytotoxic to endothelial cells overexpressing VEGFR-2 but not to endothelial cells overexpressing VEGFR-1. In this study, we examined the basis for the specific toxicity of this construct and assessed its intracellular effects in vitro and in vivo. Methods We investigated the binding, cytotoxicity and internalization profile of VEGF121/rGel on endothelial cells expressing VEGFR-1 or VEGFR-2, identified its effects on angiogenesis models in vitro and ex vivo, and explored its intracellular effects on a number of molecular pathways using microarray analysis. Results Incubation of PAE/VEGFR-2 and PAE/VEGFR-1 cells with 125I-VEGF121/rGel demonstrated binding specificity that was competed with unlabeled VEGF121/rGel but not with unlabeled gelonin. Assessment of the effect of VEGF121/rGel on blocking tube formation in vitro revealed a 100-fold difference in IC50 levels between PAE/VEGFR-2 (1 nM and PAE/VEGFR-1 (100 nM cells. VEGF121/rGel entered PAE/VEGFR-2 cells within one hour of treatment but was not detected in PAE/VEGFR-1 cells up to 24 hours after treatment. In vascularization studies using chicken chorioallantoic membranes, 1 nM VEGF121/rGel completely inhibited bFGF-stimulated neovascular growth. The cytotoxic effects of VEGF121/rGel were not apoptotic since treated cells were TUNEL-negative with no evidence of PARP cleavage or alteration in the protein levels of select apoptotic markers. Microarray analysis of VEGF121/rGel-treated HUVECs revealed the upregulation of a unique "fingerprint" profile of 22 genes that control cell adhesion, apoptosis, transcription regulation, chemotaxis, and inflammatory response. Conclusions Taken together, these data confirm the selectivity of VEGF121/rGel for VEGFR-2

  1. Ulcerative colitis specific cytotoxic IgG-autoantibodies against colonic epithelial cancer cells.

    OpenAIRE

    Auer, I O; Grosch, L; Hardörfer, C; A. Röder

    1988-01-01

    Serum antibodies cytotoxic to the colon cancer cell line RPMI 4788 were studied in 42 patients with ulcerative colitis, 61 patients with Crohn's disease, 27 patients with other inflammatory diseases (disease-controls) and 22 healthy controls. Cytotoxicity of antibodies towards RPMI 4788 was studied by means of a chromium release assay using peripheral blood mononuclear leucocytes of healthy subjects as effector cells. Using a four hour antibody dependent cell mediated cytotoxicity assay sera ...

  2. Newly synthesized hypoxia-mediated drugs as radiosensitizers and cytotoxic agents

    International Nuclear Information System (INIS)

    This paper describes experiments with mammalian cells in vitro to compare the radiosensitizing and cytotoxic properties of five newly synthesized hypoxia mediated drugs with the current drug in use, misonidazole. Attention has focused on the need to synthesize or identify compounds with equal or greater effectiveness but at the same time exhibiting less serious side effects

  3. Taurine protects HK-2 cells from oxidized LDL-induced cytotoxicity via the ROS-mediated mitochondrial and p53-related apoptotic pathways

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Chun-Yu [Graduate Institute of Biomedical Sciences, National Chung Hsing University, Taichung, Taiwan (China); Shen, Chao-Yu [School of Medical Imaging and Radiological Sciences, Chung Shan Medical University, Taichung, Taiwan (China); Department of Medical Imaging, Chung Shan Medical University Hospital, Taichung, Taiwan (China); School of Medicine, Chung Shan Medical University, Taichung, Taiwan (China); Kang, Chao-Kai [Department of Life Sciences, National Chung Hsing University, Taichung, Taiwan, (China); Sher, Yuh-Pyng [Graduate Institute of Clinical Medical Science, China Medical University, Taichung, Taiwan (China); Center for Molecular Medicine, China Medical University Hospital, Taichung 404, Taiwan (China); Sheu, Wayne H.-H. [Graduate Institute of Biomedical Sciences, National Chung Hsing University, Taichung, Taiwan (China); Division of Endocrinology and Metabolism, Department of Internal Medicine, Taichung Veterans General Hospital, Taichung, Taiwan (China); School of Medicine, National Yang Ming University, Taipei, Taiwan (China); School of Medicine, National Defense Medical Center, Taipei, Taiwan (China); Chang, Chia-Che, E-mail: chia_che@dragon.nchu.edu.tw [Graduate Institute of Biomedical Sciences, National Chung Hsing University, Taichung, Taiwan (China); Agricultural Biotechnology Center, National Chung Hsing University, Taichung, Taiwan (China); Lee, Tsung-Han, E-mail: thlee@email.nchu.edu.tw [Department of Life Sciences, National Chung Hsing University, Taichung, Taiwan, (China); Graduate Institute of Clinical Medical Science, China Medical University, Taichung, Taiwan (China); Agricultural Biotechnology Center, National Chung Hsing University, Taichung, Taiwan (China); Department of Biological Science and Technology, China Medical University, Taichung, Taiwan (China)

    2014-09-15

    Oxidized LDL (oxLDL) induces a pro-oxidative environment and promotes apoptosis, causing the progression of renal diseases in humans. Taurine is a semi-essential amino acid in mammals and has been shown to be a potent endogenous antioxidant. The kidney plays a pivotal role in maintaining the balance of taurine. However, the mechanisms underlying the protective effects of taurine against oxLDL-induced injury in renal epithelial cells have not been clarified. In the present study, we investigated the anti-apoptotic effects of taurine on human proximal tubular epithelial (HK-2) cells exposed to oxLDL and explored the related mechanisms. We observed that oxLDL increased the contents of ROS and of malondialdehyde (MDA), which is a lipid peroxidation by-product that acts as an indicator of the cellular oxidation status. In addition, oxLDL induced cell death and apoptosis in HK-2 cells. Pretreatment with taurine at 100 μM significantly attenuated the oxLDL-induced cytotoxicity. We determined that oxLDL triggered the phosphorylation of ERK and, in turn, the activation of p53 and other apoptosis-related events, including calcium accumulation, destabilization of the mitochondrial permeability and disruption of the balance between pro-apoptotic Bax and anti-apoptotic Bcl-2 proteins. The malfunctions induced by oxLDL were effectively blocked by taurine. Thus, our results suggested that taurine exhibits potential therapeutic activity by preventing oxLDL-induced nephrotoxicity. The inhibition of oxLDL-induced epithelial apoptosis by taurine was at least partially due to its anti-oxidant activity and its ability to modulate the ERK and p53 apoptotic pathways. - Highlights: • Oxidized LDL induced cytotoxicity and apoptosis in HK-2 cells. • Pretreatment with taurine attenuated oxLDL-induced nephrotoxicity. • Taurine protected against renal damages through inhibition of ROS generation. • Taurine prevented apoptosis through modulation of the p53 phosphorylation.

  4. Taurine protects HK-2 cells from oxidized LDL-induced cytotoxicity via the ROS-mediated mitochondrial and p53-related apoptotic pathways

    International Nuclear Information System (INIS)

    Oxidized LDL (oxLDL) induces a pro-oxidative environment and promotes apoptosis, causing the progression of renal diseases in humans. Taurine is a semi-essential amino acid in mammals and has been shown to be a potent endogenous antioxidant. The kidney plays a pivotal role in maintaining the balance of taurine. However, the mechanisms underlying the protective effects of taurine against oxLDL-induced injury in renal epithelial cells have not been clarified. In the present study, we investigated the anti-apoptotic effects of taurine on human proximal tubular epithelial (HK-2) cells exposed to oxLDL and explored the related mechanisms. We observed that oxLDL increased the contents of ROS and of malondialdehyde (MDA), which is a lipid peroxidation by-product that acts as an indicator of the cellular oxidation status. In addition, oxLDL induced cell death and apoptosis in HK-2 cells. Pretreatment with taurine at 100 μM significantly attenuated the oxLDL-induced cytotoxicity. We determined that oxLDL triggered the phosphorylation of ERK and, in turn, the activation of p53 and other apoptosis-related events, including calcium accumulation, destabilization of the mitochondrial permeability and disruption of the balance between pro-apoptotic Bax and anti-apoptotic Bcl-2 proteins. The malfunctions induced by oxLDL were effectively blocked by taurine. Thus, our results suggested that taurine exhibits potential therapeutic activity by preventing oxLDL-induced nephrotoxicity. The inhibition of oxLDL-induced epithelial apoptosis by taurine was at least partially due to its anti-oxidant activity and its ability to modulate the ERK and p53 apoptotic pathways. - Highlights: • Oxidized LDL induced cytotoxicity and apoptosis in HK-2 cells. • Pretreatment with taurine attenuated oxLDL-induced nephrotoxicity. • Taurine protected against renal damages through inhibition of ROS generation. • Taurine prevented apoptosis through modulation of the p53 phosphorylation

  5. Reactive oxygen species mediated DNA damage in human lung alveolar epithelial (A549) cells from exposure to non-cytotoxic MFI-type zeolite nanoparticles.

    Science.gov (United States)

    Bhattacharya, Kunal; Naha, Pratap C; Naydenova, Izabela; Mintova, Svetlana; Byrne, Hugh J

    2012-12-17

    Increasing utilization of engineered nanoparticles in the field of electronics and biomedical applications demands an assessment of risk associated with deliberate or accidental exposure. Metal based nanoparticles are potentially most important of all the nanoparticles in terms of health risks. Microporous alumino-silicates and pure silicates named as zeolites and zeo-type materials with variety of structures, chemical compositions, particle sizes and morphologies have a significant number of industrial uses such as in catalysis, sorption and ion-exchange processes. In particular, the nanosized particles due to their unique properties are used in hybrid organic-inorganic materials for photography, photonics, electronics, labeling, imaging, and sensing. The aim of the current study is to investigate pure silica MFI-type zeolites nanoparticles with sizes of 50nm and 100nm (samples MFI-50 and MFI-100) under suspended conditions and their toxicological effects on human lung alveolar (A549) cells under in vitro conditions. Live cell imaging showed that the nanoparticles precipitated from the colloidal suspension of cell culture media as large agglomerates, coming in contact with the cell surface through sedimentation. A cellular proliferative capacity test showed the zeolite nanoparticles to exhibit no significant cytotoxicity below a concentration of 100μg/ml. However, both the MFI-50 and MFI-100 nanoparticles induced high intracellular reactive oxygen species (ROS) generation and elevated mitochondrial membrane potential in the A549 cells over the measured time period of 12h and at concentrations up to ≤50μg/ml. DNA fragmentation analysis using the comet assay showed that the MFI-50 and MFI-100 nanoparticles cause genotoxicity in a concentration dependent manner. Furthermore, the rate at which maximum genomic damage was caused by MFI-100 nanoparticles in the A549 cells was found to be high as compared to the MFI-50 nanoparticles. However, the damage caused by the

  6. Tamoxifen-induced cytotoxicity in breast cancer cells is mediated by glucose-regulated protein 78 (GRP78) via AKT (Thr308) regulation.

    Science.gov (United States)

    Pujari, Radha; Jose, Jemy; Bhavnani, Varsha; Kumar, Natesh; Shastry, Padma; Pal, Jayanta K

    2016-08-01

    Glucose regulated protein 78 (GRP78) has recently been suggested to be associated with drug resistance in breast cancer patients. However, the precise role of GRP78 in drug resistance and the involved signaling pathways are not clearly understood. In the present study, we show that among a panel of drugs, namely Paclitaxel (TAX), Doxorubicin (DOX), 5-fluorouracil (5-FU), UCN-01 and Tamoxifen (TAM) used, TAM alone up-regulated the expression of GRP78 significantly and induced apoptosis in MCF-7 and MDA-MB-231 cells. Interestingly, inhibition of GRP78 by a specific pharmacological inhibitor, VER-155008 augmented TAM-induced apoptosis, and overexpression of GRP78 rendered the cells resistant to TAM-induced cell death suggesting a role for GRP78 in TAM-induced cytotoxicity. Mechanistically, the expression of phosphorylated AKT as determined by Western blot analyses revealed that TAM selectively upregulated phosphorylation of AKT at Thr308 but not at Ser473, and siRNA silencing of GRP78 resulted in inhibition of AKT phosphorylation at Thr308 but not at Ser473. Further, a GRP78 inhibitor, VER155008 inhibited TAM-induced phosphorylation of GSK3β, a downstream substrate of AKT. These results, thus suggests a role for GRP78 in TAM-induced AKT activation. Additionally, co-localization studies by immunofluorescence, and immunoprecipitation experiments demonstrated a complex formation of AKT and GRP78. Furthermore, in glucose-free medium, the cells were sensitized to TAM-induced cell death that was associated with reduced AKT phosphorylation at Thr308, thus strengthening the association of AKT regulation with drug response. Collectively, our findings identify a role of GRP78 in AKT regulation in response to TAM in breast cancer cells. PMID:27262235

  7. Murine cellular cytotoxicity to syngeneic and xenogeneic herpes simplex virus-infected cells.

    Science.gov (United States)

    Kohl, S; Drath, D B; Loo, L S

    1982-12-01

    Cellular cytotoxicity of C57BL/6 adult mice peritoneal cells to xenogeneic (Chang liver) and syngeneic (BL/6-WT3) herpes simplex virus (HSV)-infected cells was analyzed in a 6-h 51Cr release assay. There was no difference in antibody-dependent cellular cytotoxicity to either target. There was no natural killer cytotoxicity to targets with cells from uninfected mice except at very high effector cell ratios. HSV-infected (2 X 10(4) PFU intraperitoneally 1 day previously) mice mediated significantly higher antibody-dependent cellular cytotoxicity and required less antibody (10(-5) versus 10(-2) dilution), fewer cells, and less time to kill than cells from uninfected mice. HSV-infected mice mediated natural killer cytotoxicity but preferentially killed syngeneic HSV-infected cells. Stimulation of cytotoxicity was not virus specific since influenza-infected mice mediated similar levels of cytotoxicity to HSV-infected targets. There was no difference in morphology (95% macrophage) or in the percentage of FcR-positive cells, but infected mice had more peritoneal cells and generated higher levels of superoxide in response to opsonized zymosan or phorbolmyristate acetate. These data demonstrate nonspecific virus-stimulated metabolic and effector cell function which may enhance clearance of virus in an infected host. PMID:6295943

  8. CD8+ T-cell Cytotoxic Capacity Associated with Human Immunodeficiency Virus-1 Control Can Be Mediated through Various Epitopes and Human Leukocyte Antigen Types

    OpenAIRE

    Migueles, Stephen A.; Daniel Mendoza; Matthew G. Zimmerman; Kelly M. Martins; Toulmin, Sushila A.; Kelly, Elizabeth P.; Peterson, Bennett A.; Johnson, Sarah A; Eric Galson; Poropatich, Kate O.; Andy Patamawenu; Hiromi Imamichi; Alexander Ober; Rehm, Catherine A.; Sara Jones

    2015-01-01

    Understanding natural immunologic control over Human Immunodeficiency Virus (HIV)-1 replication, as occurs in rare long-term nonprogressors/elite controllers (LTNP/EC), should inform the design of efficacious HIV vaccines and immunotherapies. Durable control in LTNP/EC is likely mediated by highly functional virus-specific CD8+ T-cells. Protective Human Leukocyte Antigen (HLA) class I alleles, like B*27 and B*57, are present in most, but not all LTNP/EC, providing an opportunity to investigat...

  9. Natural dietary anti-cancer chemopreventive compounds: redox-mediated differential signaling mechanisms in cytoprotection of normal cellsversus cytotoxicity in tumor cells

    Institute of Scientific and Technical Information of China (English)

    Sujit NAIR; Wenge LI; Ah-Ng Tony KONG

    2007-01-01

    Many dietary phytochemicals exhibit health-beneficial effects including preven-tion of diseases such as cancer, as well as neurological, cardiovascular, inflam-matory, and metabolic diseases. Evolutionarily, herbivorous and omnivorous animals have been ingesting plants. This interaction between "animal-plant"ecosystems has resulted in an elaborate system of detoxification and defense mechanisms evolved by animals including humans. Mammalian cells, including human cells, respond to these dietary phytochemicals by "non-classical receptor sensing" mechanisms of electrophilic chemical-stress typified by "thiol-modu-lated" cellular signaling events primarily leading to the gene expression of phar-macologically beneficial effects, but sometimes unwanted cytotoxicity also. Our laboratory has been studying two groups of dietary phytochemical cancer-chemopreventive compounds (isothiocyanates and polyphenols), which are effective in chemical-induced, as well as genetically-induced, animal carcinogen-esis models. These compounds typically generate "cellular stress" and modulate gene expression of phase Ⅱ detoxifying/antioxidant enzymes. Electrophiles, reac-tive oxygen species, and reactive nitrogen species are known to act as second messengers in the modulation of many cellular signaling pathways leading to gene expression changes and pharmacological responses. Redox-sensitive tran-scription factors such as nuclear factor-E2-related factor 2 (Nrf2), AP-1, NF-κB, to cite a few examples, sense and transduce changes in the cellular redox status and modulate gene expression responses to oxidative and electrophilic stresses, pre-sumably via sulfhydryl modification of critical cysteine residues found on these proteins and/or other upstream redox-sensitive molecular targets. In the current review, we will explore dietary cancer chemopreventive phytochemicals, discuss the link between oxidative/electrophilic stresses and the redox circuitry, and con-sider different redox

  10. Improved Antibody-Dependent Cell-Mediated Cytotoxicity (ADCC) of Affinity Maturated and Fc-Engineered Antibodies Directed Against the AML Stem Cell Antigen CD96

    OpenAIRE

    Mohseni Nodehi, Sahar

    2011-01-01

    Regardless of progress in the therapy of AML, there is no long-term cure for about 70% of AML patients. Leukemic stem cells seem to be an important key for the perpetuation of AML.Most currently used chemotherapeutic agents are not able to eliminate AML-LSCs. The combination of conventional therapies with AML-LSCs-directed therapies may eventually lead to a cure for AML patients.Recently expression of CD96 was reported on AML-LSCs, while only very low expression levels were found on normal HS...

  11. An Investigation of the Cytotoxicity and Caspase-Mediated Apoptotic Effect of Green Synthesized Zinc Oxide Nanoparticles Using Eclipta prostrata on Human Liver Carcinoma Cells

    Directory of Open Access Journals (Sweden)

    Ill-Min Chung

    2015-08-01

    Full Text Available Cancer is a leading cause of death worldwide and sustained focus is on the discovery and development of newer and better tolerated anticancer drugs, especially from plants. In the present study, a simple, eco-friendly, and inexpensive approach was followed for the synthesis of zinc oxide nanoparticles (ZnO NPs using the aqueous leaf extract of Eclipta prostrata. The synthesized ZnO NPs were characterized by UV-visible absorption spectroscopy, X-ray diffraction (XRD, Fourier transform infrared spectroscopy (FTIR, Scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX, High-resolution transmission electron microscopy (HRTEM, and Selected area (electron diffraction (SAED. The HRTEM images confirmed the presence of triangle, radial, hexagonal, rod, and rectangle, shaped with an average size of 29 ± 1.3 nm. The functional groups for synthesized ZnO NPs were 3852 cm−1 for H-H weak peak, 3138 cm−1 for aromatic C-H extend, and 1648 cm−1 for Aromatic ring stretch. The 3-(4,5-Dimethylthiazol-2-yl-2,5-Diphenyltetrazolium Bromide (MTT, caspase and DNA fragmentation assays were carried out using various concentrations of ZnO NPs ranging from 1 to 100 mg/mL. The synthesized ZnO NPs showed dose dependent cytopathic effects in the Hep-G2 cell line. At 100 mg/mL concentration, the synthesized ZnO NPs exhibited significant cytotoxic effects and the apoptotic features were confirmed through caspase-3 activation and DNA fragmentation assays.

  12. Murine cellular cytotoxicity to syngeneic and xenogeneic herpes simplex virus-infected cells.

    OpenAIRE

    Kohl, S; Drath, D B; Loo, L S

    1982-01-01

    Cellular cytotoxicity of C57BL/6 adult mice peritoneal cells to xenogeneic (Chang liver) and syngeneic (BL/6-WT3) herpes simplex virus (HSV)-infected cells was analyzed in a 6-h 51Cr release assay. There was no difference in antibody-dependent cellular cytotoxicity to either target. There was no natural killer cytotoxicity to targets with cells from uninfected mice except at very high effector cell ratios. HSV-infected (2 X 10(4) PFU intraperitoneally 1 day previously) mice mediated significa...

  13. Impaired antibody-dependent cellular cytotoxicity mediated by herceptin in patients with gastric cancer.

    Science.gov (United States)

    Kono, Koji; Takahashi, Akihiro; Ichihara, Fumiko; Sugai, Hidemitsu; Fujii, Hideki; Matsumoto, Yoshirou

    2002-10-15

    The humanized monoclonal antibody Herceptin, which specifically targets HER-2/neu, exhibits growth inhibitory activity against HER-2/neu-overexpressing tumors and is approved for therapeutic use with proved survival benefit in patients with HER-2/neu-positive breast cancer. In the present study, we investigated whether Herceptin could affect the HER-2/neu-overexpressing gastric cancer cells based on antibody-dependent cell-mediated cytotoxicity (ADCC) and compared immune effector cells from gastric cancer patients with normal individuals on ADCC. HER-2/neu-expressing gastric cancer cells could be killed by Herceptin-mediated ADCC and the Herceptin-induced ADCC correlated with the degree of HER-2/neu expression on the gastric cancer cells. However, the Herceptin-mediated ADCC was significantly impaired in peripheral blood mononuclear cells from advanced disease patients (n = 10) compared with that in early disease (n = 12; P = 0.04) or healthy individuals (n = 10, P = 0.02). Moreover, natural killer (NK) cells purified from patients with advanced disease indicated less Herceptin-mediated ADCC in comparison with that from healthy donors (P = 0.04), whereas monocytes purified from the patients showed an almost equal amount of Herceptin-mediated ADCC in comparison with that from healthy individuals, indicating that NK cell dysfunction contributed to the impaired Herceptin-mediated ADCC in gastric cancer patients. Furthermore, the NK-cell dysfunction on Herceptin-mediated ADCC correlated with the down-regulation of CD16zeta expression in the patients, and interleukin 2 ex vivo treatment of NK cells could restore the impairment of Herceptin-mediated ADCC, concomitant to the normalization of the expression of CD16zeta molecules. Thus, some modalities such as interleukin 2 treatment aimed at reversing NK dysfunction may be necessary for successful Herceptin treatment of gastric cancer. PMID:12384543

  14. Mycoplasma pneumoniae induces cytotoxic activity in guinea pig bronchoalveolar cells

    International Nuclear Information System (INIS)

    Precultured guinea pig alveolar macrophages (AM) and freshly harvested alveolar cells (FHAC) activated by interaction with Mycoplasma pneumoniae were cytotoxic for xenogeneic 75selenomethionine-labeled tumor target cells. Phagocytosis of whole opsonized or nonopsonized M. pneumoniae cells was more effective in eliciting cytotoxicity than uptake of sonicated microorganisms. The addition of living mycoplasma cells to the assay system enhanced the cytotoxic effect considerably. Target cells were significantly more susceptible to the cytotoxic action of phagocytes if they were coated with mycoplasma antigen or cocultured together with M. pneumoniae. The activation of the phagocytes could be inhibited by 2-deoxy-D-glucose but not by antimicrobial substances suppressing mycoplasma protein synthesis. It was accompanied by 51Cr release without detectable signs of cell damage. The supernatants of activated cells were cytotoxic for approximately 24 h. Inhibition, release, and cytotoxic activity indicate the necessity of an intact metabolism of the effector cells and suggest a secretion of cytotoxic substances

  15. Abrogation of TNF-mediated cytotoxicity by space flight involves protein kinase C

    Science.gov (United States)

    Woods, K. M.; Chapes, S. K.; Spooner, B. S. (Principal Investigator)

    1994-01-01

    Experiments conducted on STS-50 indicated that space flight significantly inhibited tumor necrosis factor (TNF)-mediated killing of LM929 cells compared to ground controls. In ground-based studies, activation of protein kinase C (PKC) with phorbol 12-myristate 13-acetate (PMA) also inhibited TNF-mediated killing of LM929 cells. Therefore, we used PKC inhibitors to determine if the inhibitory effects of spaceflight on TNF-mediated cytotoxicity involved the activation of PKC. In experiments conducted onboard space shuttle mission STS-54, we saw that in the presence of the protein kinase C inhibitors H7 and H8, TNF-mediated cytotoxicity was restored to levels of those observed in the ground controls. Subsequent experiments done during the STS-57 mission tested the dose response of two protein kinase inhibitors, H7 and HA1004. We again saw that killing was restored in a dose-dependent manner, with inhibitor concentrations known to inhibit PKC being most effective. These data suggest that space flight ameliorates the action of TNF by affecting PKC in target cells.

  16. Neuroprotective Activity of (−)-Epigallocatechin Gallate against Lipopolysaccharide-Mediated Cytotoxicity

    Science.gov (United States)

    Liu, Jin-Biao; Zhou, Li; Wang, Yi-Zhong; Wang, Xu; Zhou, Yu; Ho, Wen-Zhe; Li, Jie-Liang

    2016-01-01

    Lipopolysaccharide- (LPS-) mediated systemic inflammation plays a critical role in neurodegenerative diseases. The present study was conducted to evaluate the protective effects of epigallocatechin gallate (EGCG), the major component in green tea, on LPS-mediated inflammation and neurotoxicity. LPS treatment of macrophages induced expression of proinflammatory cytokines (TNF-α, IL-1β, and IL-6). However, EGCG pretreatment of macrophages significantly inhibited LPS-mediated induction of these cytokines. In addition, EGCG significantly diminished LPS-induced inflammatory cytokines in the peripheral mononuclear blood cells (PBMCs). Supernatant from EGCG-pretreated and LPS-activated macrophage cultures was found to be less cytotoxic to neurons than that from non-EGCG-pretreated and LPS-activated macrophage cultures. Furthermore, EGCG treatment of neurons could inhibit LPS-induced production of reactive oxygen species (ROS). Thus EGCG represents a potent and useful neuroprotective agent for inflammation-mediated neurological disorders.

  17. Cytotoxic activity of allogeneic natural killer cells on U251 glioma cells in vitro.

    Science.gov (United States)

    Guo, Meng; Wu, Tingting; Wan, Lixin

    2016-07-01

    The present study aimed to observe the cytotoxic activity of allogeneic natural killer (NK) cells on U251 glioma cells and to investigate their mechanism of action to establish an effective treatment strategy for neuroglioma. Cell survival curves, colony formation assays and karyotype analysis were performed to investigate the characteristics of U251 glioma cells. The present study demonstrated that natural killer group 2, member D (NKG2D)‑major histocompatibility complex class I‑related chain A/B (MICA/B) interactions contributed to the cytotoxic effect of NK cells on K562 and U251 cells. In antibody‑blocking assays to inhibit NKG2D ligands, the cytotoxic activity was not completely attenuated, which suggested that other signaling pathways contribute to the cytotoxic activity of NK cells on tumor cells in addition to the NKG2D‑mediated activity. The present study identified that the expression levels of NKG2D ligands on the surface of target cells influenced the strength of the NK cell immune response. Furthermore, allogeneic NK cells were observed to kill glioma cells in vitro, and this anticancer activity is associated with the rate of NKG2D expression on the surface of glioma cells. PMID:27175912

  18. Bio-mediated synthesis, characterization and cytotoxicity of gold nanoparticles.

    Science.gov (United States)

    Klekotko, Magdalena; Matczyszyn, Katarzyna; Siednienko, Jakub; Olesiak-Banska, Joanna; Pawlik, Krzysztof; Samoc, Marek

    2015-11-21

    We report here a "green" approach for the synthesis of gold nanoparticles (GNPs) in which the Mentha piperita extract was applied for the bioreduction of chloroauric acid and the stabilization of the formed nanostructures. The obtained GNPs were characterized by UV-Vis absorption spectroscopy and transmission electron microscopy (TEM). The reduction of gold ions with the plant extract leads to the production of nanoparticles with various shapes (spherical, triangular and hexagonal) and sizes (from 10 to 300 nm). The kinetics of the reaction was monitored and various conditions of the synthesis were investigated. As a result, we established protocols optimized towards the synthesis of nanospheres and nanoprisms of gold. The cytotoxic effect of the obtained gold nanoparticles was studied by performing MTT assay, which showed lower cytotoxicity of the biosynthesized GNPs compared to gold nanorods synthesized using the usual seed-mediated growth. The results suggest that the synthesis using plant extracts may be a useful method to produce gold nanostructures for various biological and medical applications. PMID:26456245

  19. Base-mediated decomposition of amide-substituted furfuryl tosylhydrazones: synthesis and cytotoxic activities of enynyl-ketoamides.

    Science.gov (United States)

    Ji, Fanghua; Peng, Hui; Zhang, Xiaoting; Lu, Wenhua; Liu, Shubin; Jiang, Huanfeng; Liu, Bo; Yin, Biaolin

    2015-02-20

    Base-mediated decomposition of amide-substituted furfuryl tosylhydrazones afforded practical access to novel multifunctionalized enynyl-ketoamides. In addition, furfuryl tosylhydrazones with stable furan rings underwent an interesting tosyl-group migration to form sulfones, which have potential synthetic applications. Some of the obtained enynyl-ketoamides demonstrated good cytotoxicities against human tumor cell lines. PMID:25635471

  20. Cytotoxic-T-Lymphocyte Antigen 4 Receptor Signaling for Lymphocyte Adhesion Is Mediated by C3G and Rap1

    OpenAIRE

    Kloog, Yoel; Mor, Adam

    2014-01-01

    T-lymphocyte adhesion plays a critical role in both inflammatory and autoimmune responses. The small GTPase Rap1 is the key coordinator mediating T-cell adhesion to endothelial cells, antigen-presenting cells, and virus-infected cells. We describe a signaling pathway, downstream of the cytotoxic T-lymphocyte antigen 4 (CTLA-4) receptor, leading to Rap1-mediated adhesion. We identified a role for the Rap1 guanine nucleotide exchange factor C3G in the regulation of T-cell adhesion and showed th...

  1. Comparison of nanoparticle-mediated transfection methods for DNA expression plasmids: efficiency and cytotoxicity

    Directory of Open Access Journals (Sweden)

    Nolte Ingo

    2011-10-01

    Full Text Available Abstract Background Reproducibly high transfection rates with low methodology-induced cytotoxic side effects are essential to attain the required effect on targeted cells when exogenous DNA is transfected. Different approaches and modifications such as the use of nanoparticles (NPs are being evaluated to increase transfection efficiencies. Several studies have focused on the attained transfection efficiency after NP-mediated approaches. However, data comparing toxicity of these novel approaches with conventional methods is still rare. Transfection efficiency and methodology-induced cytotoxicity were analysed after transfection with different NP-mediated and conventional approaches. Two eukaryotic DNA-expression-plasmids were used to transfect the mammalian cell line MTH53A applying six different transfection protocols: conventional transfection reagent (FuGENE HD, FHD, FHD in combination with two different sizes of stabilizer-free laser-generated AuNPs (PLAL-AuNPs_S1,_S2, FHD and commercially available AuNPs (Plano-AuNP, and two magnetic transfection protocols. 24 h post transfection efficiency of each protocol was analysed using fluorescence microscopy and GFP-based flow cytometry. Toxicity was assessed measuring cell proliferation and percentage of propidium iodide (PI% positive cells. Expression of the respective recombinant proteins was evaluated by immunofluorescence. Results The addition of AuNPs to the transfection protocols significantly increased transfection efficiency in the pIRES-hrGFPII-eIL-12 transfections (FHD: 16%; AuNPs mean: 28%, whereas the magnet-assisted protocols did not increase efficiency. Ligand-free PLAL-AuNPs had no significant cytotoxic effect, while the ligand-stabilized Plano-AuNPs induced a significant increase in the PI% and lower cell proliferation. For pIRES-hrGFPII-rHMGB1 transfections significantly higher transfection efficiency was observed with PLAL-AuNPs (FHD: 31%; PLAL-AuNPs_S1: 46%; PLAL-AuNPs_S2: 50

  2. Developmental cell death programs license cytotoxic cells to eliminate histocompatible partners.

    Science.gov (United States)

    Corey, Daniel M; Rosental, Benyamin; Kowarsky, Mark; Sinha, Rahul; Ishizuka, Katherine J; Palmeri, Karla J; Quake, Stephen R; Voskoboynik, Ayelet; Weissman, Irving L

    2016-06-01

    In a primitive chordate model of natural chimerism, one chimeric partner is often eliminated in a process of allogeneic resorption. Here, we identify the cellular framework underlying loss of tolerance to one partner within a natural Botryllus schlosseri chimera. We show that the principal cell type mediating chimeric partner elimination is a cytotoxic morula cell (MC). Proinflammatory, developmental cell death programs render MCs cytotoxic and, in collaboration with activated phagocytes, eliminate chimeric partners during the "takeover" phase of blastogenic development. Among these genes, the proinflammatory cytokine IL-17 enhances cytotoxicity in allorecognition assays. Cellular transfer of FACS-purified MCs from allogeneic donors into recipients shows that the resorption response can be adoptively acquired. Transfer of 1 × 10(5) allogeneic MCs eliminated 33 of 78 (42%) recipient primary buds and 20 of 76 (20.5%) adult parental adult organisms (zooids) by 14 d whereas transfer of allogeneic cell populations lacking MCs had only minimal effects on recipient colonies. Furthermore, reactivity of transferred cells coincided with the onset of developmental-regulated cell death programs and disproportionately affected developing tissues within a chimera. Among chimeric partner "losers," severe developmental defects were observed in asexually propagating tissues, reflecting a pathologic switch in gene expression in developmental programs. These studies provide evidence that elimination of one partner in a chimera is an immune cell-based rejection that operates within histocompatible pairs and that maximal allogeneic responses involve the coordination of both phagocytic programs and the "arming" of cytotoxic cells. PMID:27217570

  3. Immune checkpoint inhibitors enhance cytotoxicity of cytokine-induced killer cells against human myeloid leukaemic blasts.

    Science.gov (United States)

    Poh, Su Li; Linn, Yeh Ching

    2016-05-01

    We studied whether blockade of inhibitory receptors on cytokine-induced killer (CIK) cells by immune checkpoint inhibitors could increase its anti-tumour potency against haematological malignancies. CIK cultures were generated from seven normal donors and nine patients with acute myeloid leukaemia (AML), acute lymphoblastic leukaemia (ALL) or multiple myeloma (MM). The inhibitory receptors B and T lymphocyte attenuator, CD200 receptor, lymphocyte activation gene-3 (LAG-3) and T cell immunoglobulin and mucin-domain-containing-3 (TIM-3) were present at variable percentages in most CIK cultures, while cytotoxic T lymphocyte-associated protein 4 (CTLA-4), programmed death-1 (PD-1) and killer cell immunoglobulin-like receptors (KIR2DL1/2/3) were expressed at low level in most cultures. Without blockade, myeloid leukaemia cells were susceptible to autologous and allogeneic CIK-mediated cytotoxicity. Blockade of KIR, LAG-3, PD-1 and TIM-3 but not CTLA-4 resulted in remarkable increase in killing against these targets, even in those with poor baseline cytotoxicity. ALL and MM targets were resistant to CIK-mediated cytotoxicity, and blockade of receptors did not increase cytotoxicity to a meaningful extent. Combination of inhibitors against two receptors did not further increase cytotoxicity. Interestingly, potentiation of CIK killing by blocking antibodies was not predicted by expression of receptors on CIK and their respective ligands on the targets. Compared to un-activated T and NK cells, blockade potentiated the cytotoxicity of CIK cells to a greater degree and at a lower E:T ratio, but without significant increase in cytotoxicity against normal white cell. Our findings provide the basis for clinical trial combining autologous CIK cells with checkpoint inhibitors for patients with AML. PMID:26961084

  4. Natural CD8{sup +}25{sup +} regulatory T cell-secreted exosomes capable of suppressing cytotoxic T lymphocyte-mediated immunity against B16 melanoma

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Yufeng; Zhang, Xueshu; Zhao, Tuo; Li, Wei; Xiang, Jim, E-mail: jim.xiang@saskcancer.ca

    2013-08-16

    Highlights: •CD8{sup +}25{sup +} regulatory T cells secrete tolerogenic exosomes. •CD8{sup +}25{sup +} regulatory T cell-derived exosomes exhibit immunosuppressive effect. •CD8{sup +}25{sup +} regulatory T cell-derived exosomes inhibit antitumor immunity. -- Abstract: Natural CD4{sup +}25{sup +} and CD8{sup +}25{sup +} regulatory T (Tr) cells have been shown to inhibit autoimmune diseases. Immune cells secrete exosomes (EXOs), which are crucial for immune regulation. However, immunomodulatory effect of natural Tr cell-secreted EXOs is unknown. In this study, we purified natural CD8{sup +}25{sup +} Tr cells from C57BL/6 mouse naive CD8{sup +} T cells, and in vitro amplified them with CD3/CD28 beads. EXOs (EXO{sub Tr}) were purified from Tr cell’s culture supernatants by differential ultracentrifugation and analyzed by electron microscopy, Western blot and flow cytometry. Our data showed that EXO{sub Tr} had a “saucer” or round shape with 50–100 nm in diameter, contained EXO-associated markers LAMP-1 and CD9, and expressed natural Tr cell markers CD25 and GITR. To assess immunomodulatory effect, we i.v. immunized C57BL/6 mice with ovalbumin (OVA)-pulsed DCs (DC{sub OVA}) plus Tr cells or EXO{sub Tr}, and then assessed OVA-specific CD8{sup +} T cell responses using PE-H-2K{sup b}/OVA tetramer and FITC-anti-CD8 antibody staining by flow cytometry and antitumor immunity in immunized mice with challenge of OVA-expressing BL6–10{sub OVA} melanoma cells. We demonstrated that DC{sub OVA}-stimulated CD8{sup +} T cell responses and protective antitumor immunity significantly dropped from 2.52% to 1.08% and 1.81% (p < 0.05), and from 8/8 to 2/8 and 5/8 mice DC{sub OVA} (p < 0.05) in immunized mice with co-injection of Tr cells and EXO{sub Tr}, respectively. Our results indicate that natural CD8{sup +}25{sup +} Tr cell-released EXOs, alike CD8{sup +}25{sup +} Tr cells, can inhibit CD8{sup +} T cell responses and antitumor immunity. Therefore, EXOs derived from

  5. Natural CD8+25+ regulatory T cell-secreted exosomes capable of suppressing cytotoxic T lymphocyte-mediated immunity against B16 melanoma

    International Nuclear Information System (INIS)

    Highlights: •CD8+25+ regulatory T cells secrete tolerogenic exosomes. •CD8+25+ regulatory T cell-derived exosomes exhibit immunosuppressive effect. •CD8+25+ regulatory T cell-derived exosomes inhibit antitumor immunity. -- Abstract: Natural CD4+25+ and CD8+25+ regulatory T (Tr) cells have been shown to inhibit autoimmune diseases. Immune cells secrete exosomes (EXOs), which are crucial for immune regulation. However, immunomodulatory effect of natural Tr cell-secreted EXOs is unknown. In this study, we purified natural CD8+25+ Tr cells from C57BL/6 mouse naive CD8+ T cells, and in vitro amplified them with CD3/CD28 beads. EXOs (EXOTr) were purified from Tr cell’s culture supernatants by differential ultracentrifugation and analyzed by electron microscopy, Western blot and flow cytometry. Our data showed that EXOTr had a “saucer” or round shape with 50–100 nm in diameter, contained EXO-associated markers LAMP-1 and CD9, and expressed natural Tr cell markers CD25 and GITR. To assess immunomodulatory effect, we i.v. immunized C57BL/6 mice with ovalbumin (OVA)-pulsed DCs (DCOVA) plus Tr cells or EXOTr, and then assessed OVA-specific CD8+ T cell responses using PE-H-2Kb/OVA tetramer and FITC-anti-CD8 antibody staining by flow cytometry and antitumor immunity in immunized mice with challenge of OVA-expressing BL6–10OVA melanoma cells. We demonstrated that DCOVA-stimulated CD8+ T cell responses and protective antitumor immunity significantly dropped from 2.52% to 1.08% and 1.81% (p OVA (p Tr, respectively. Our results indicate that natural CD8+25+ Tr cell-released EXOs, alike CD8+25+ Tr cells, can inhibit CD8+ T cell responses and antitumor immunity. Therefore, EXOs derived from natural CD4+25+ and CD8+25+ Tr cells may become an alternative for immunotherapy of autoimmune diseases

  6. The mitochondria-independent cytotoxic effect of nelfinavir on leukemia cells can be enhanced by sorafenib-mediated mcl-1 downregulation and mitochondrial membrane destabilization

    Directory of Open Access Journals (Sweden)

    Gingelmaier Andrea

    2010-01-01

    Full Text Available Abstract Background Nelfinavir is an HIV protease inhibitor that has been used for a long period of time to treat HIV-infected individuals. It has recently emerged that nelfinavir could represent a prospective new anti-cancer drug, prompting us to test the effect of nelfinavir on leukemia cells. Methods By combining in vitro and ex vivo studies, the effect of nelfinavir on leukemia cells and non-malignant, bone marrow-derived tissue cells was analyzed. Results At a concentration of 9 μg/ml, nelfinavir induced death of 90% of HL60, IM9, and Jurkat cells. At the same concentration and treatment conditions, less than 10% of aspirated human bone marrow cells showed nelfinavir-induced cell damage. Nelfinavir-induced death of leukemia cells was accompanied by activation of caspases 3, 7, and 8. Despite caspase activation, the upregulation of the anti-apoptotic bcl-2 family member protein mcl-1 that resulted from nelfinavir treatment stabilized the mitochondrial membrane potential, resulting in primarily mitochondria-independent cell death. Pharmacological downregulation of mcl-1 expression by treatment with sorafenib (2 μg/ml significantly enhanced nelfinavir-induced apoptosis even at lower nelfinavir concentrations (5 μg/ml, but did not have additional detrimental effects on non-malignant bone marrow cells. Conclusions The ability of nelfinavir to induce apoptosis in leukemia cells as a single agent in a mitochondria-independent manner might suggest it could be used as a second or third line of treatment for leukemia patients for whom standard mitochondria-directed treatment strategies have failed. Combination treatment with nelfinavir and sorafenib might further enhance the efficacy of nelfinavir even on chemo-resistant leukemia cells.

  7. Treatment with 5-Aza-2'-Deoxycytidine Induces Expression of NY-ESO-1 and Facilitates Cytotoxic T Lymphocyte-Mediated Tumor Cell Killing

    Science.gov (United States)

    Klar, Agnes S.; Gopinadh, Jakka; Kleber, Sascha; Wadle, Andreas; Renner, Christoph

    2015-01-01

    Background NY-ESO-1 belongs to the cancer/testis antigen (CTA) family and represents an attractive target for cancer immunotherapy. Its expression is induced in a variety of solid tumors via DNA demethylation of the promoter of CpG islands. However, NY-ESO-1 expression is usually very low or absent in some tumors such as breast cancer or multiple myeloma. Therefore, we established an optimized in vitro treatment protocol for up-regulation of NY-ESO-1 expression by tumor cells using the hypomethylating agent 5-aza-2'-deoxycytidine (DAC). Methodology/Principal Findings We demonstrated de novo induction of NY-ESO-1 in MCF7 breast cancer cells and significantly increased expression in U266 multiple myeloma cells. This effect was time- and dose-dependent with the highest expression of NY-ESO-1 mRNA achieved by the incubation of 10 μM DAC for 72 hours. NY-ESO-1 activation was also confirmed at the protein level as shown by Western blot, flow cytometry, and immunofluorescence staining. The detection and quantification of single NY-ESO-1 peptides presented at the tumor cell surface in the context of HLA-A*0201 molecules revealed an increase of 100% and 50% for MCF7 and U266 cells, respectively. Moreover, the enhanced expression of NY-ESO-1 derived peptides at the cell surface was accompanied by an increased specific lysis of MCF7 and U266 cells by HLA-A*0201/NY-ESO-1(157–165) peptide specific chimeric antigen receptor (CAR) CD8+ T cells. In addition, the killing activity of CAR T cells correlated with the secretion of higher IFN-gamma levels. Conclusions/Significance These results indicate that NY-ESO-1 directed immunotherapy with specific CAR T cells might benefit from concomitant DAC treatment. PMID:26447882

  8. Endothelial cell cytotoxicity of cotton bracts tannin and aqueous cotton bracts extract

    International Nuclear Information System (INIS)

    Using an in vitro cytotoxicity assay based on the release of 51Cr from cultured porcine thoracic aortic and pulmonary arterial endothelial cells, we have demonstrated that cotton bracts tannin is a potent endothelial cell cytotoxin. It produces dose-dependent lethal injury to both types of endothelial cells with the aortic cells, being somewhat more sensitive to tannin-mediated injury than the pulmonary arterial cells. Cytotoxic injury to the cells was biphasic. During the first 3 hr of exposure to tannin, no lethal injury was detected. However, during this period, profound changes in morphology were observed suggesting sublethal injury to the cells preceded the ultimate toxic damage. Comparison of the cytotoxicity dose curves for aqueous bracts extracts with those for tannin demonstrated that tannin was major cytotoxin present in bracts

  9. MicroRNA-21-mediated regulation of Sprouty2 protein expression enhances the cytotoxic effect of 5-fluorouracil and metformin in colon cancer cells.

    Science.gov (United States)

    Feng, Yin-Hsun; Wu, Chao-Liang; Shiau, Ai-Li; Lee, Jenq-Chang; Chang, Jan-Gowth; Lu, Pei-Jung; Tung, Chao-Ling; Feng, Li-Yia; Huang, Wen-Tsung; Tsao, Chao-Jung

    2012-05-01

    Sprouty2 (Spry2) was identified recently as a tumor suppressor gene in cancer cells which inhibits the activation of receptor tyrosine kinases (RTKs). The present study explored the effect of Spry2 in colon cancer cells in order to assess its potential use in the treatment of colon cancer. Expression of Spry2 inhibited the growth of a colon cancer cell line, HCT116, and induced sensitization to fluorouracil (5-FU) and metformin. Spry2 promoted apoptosis of cancer cells in association with activation of the phosphatase and tensin homolog deleted on chromosome 10 (PTEN) pathway and the blockade of Ras-Raf-Erk signaling. Treatment of Spry2-HCT116 cells with metformin resulted in a more prominent effect on the inhibition of cell migration. Inhibition of microRNA-21 (mir‑21) induced upregulation of Spry2 and PTEN which underscores the importance of mir-21 in Spry2-associated tumorigenesis of the colon. These results point toward a potential strategy for colon cancer treatment worthy of further investigation. PMID:22322462

  10. Metabolic perturbation sensitizes human breast cancer to NK cell-mediated cytotoxicity by increasing the expression of MHC class I chain-related A/B

    OpenAIRE

    Fu, Dexue; Geschwind, Jean-Francois; Karthikeyan, Swathi; Miller, Eliyahu; Kunjithapatham, Rani; Wang, Zhijun; Ganapathy-Kanniappan, Shanmugasundaram

    2015-01-01

    Cleavage or shedding of the surface antigen, MHC class I chain-related (MIC) protein (A/B) has been known to be one of the mechanisms by which tumor cells escape host immune surveillance. Thus, any strategy to augment the surface expression of MICA/B could facilitate anticancer immune response. Here, we demonstrate that metabolic perturbation by the glycolytic inhibitor, 3-bromopyruvate (3-BrPA) augments the surface expression of MICA/B in human breast cancer cell lines, MDA-MB-231 and T47D. ...

  11. Oxidative stress-mediated cytotoxicity and apoptosis induction by TiO2 nanofibers in HeLa cells

    DEFF Research Database (Denmark)

    Ramkumar, Kunga Mohan; Manjula, Chinnasamy; GnanaKumar, Georgepeter;

    2012-01-01

    attracted a lot of attention due to their possible negative health effects as suggested by their morphological similarities with asbestos. In the present study, therefore, toxicity of TiO2NFs was evaluated in human cervical adenocarcinoma HeLa cells. The TEM and XRD analyses showed that TiO2NFs used in this...

  12. Serglycin determines secretory granule repertoire and regulates natural killer cell and cytotoxic T lymphocyte cytotoxicity.

    Science.gov (United States)

    Sutton, Vivien R; Brennan, Amelia J; Ellis, Sarah; Danne, Jill; Thia, Kevin; Jenkins, Misty R; Voskoboinik, Ilia; Pejler, Gunnar; Johnstone, Ricky W; Andrews, Daniel M; Trapani, Joseph A

    2016-03-01

    The anionic proteoglycan serglycin is a major constituent of secretory granules in cytotoxic T lymphocyte (CTL)/natural killer (NK) cells, and is proposed to promote the safe storage of the mostly cationic granule toxins, granzymes and perforin. Despite the extensive defects of mast cell function reported in serglycin gene-disrupted mice, no comprehensive study of physiologically relevant CTL/NK cell populations has been reported. We show that the cytotoxicity of serglycin-deficient CTL and NK cells is severely compromised but can be partly compensated in both cell types when they become activated. Reduced intracellular granzyme B levels were noted, particularly in CD27(+) CD11b(+) mature NK cells, whereas serglycin(-/-) TCR-transgenic (OTI) CD8 T cells also had reduced perforin stores. Culture supernatants from serglycin(-/-) OTI T cells and interleukin-2-activated NK contained increased granzyme B, linking reduced storage with heightened export. By contrast, granzyme A was not significantly reduced in cells lacking serglycin, indicating differentially regulated trafficking and/or storage for the two granzymes. A quantitative analysis of different granule classes by transmission electronmicroscopy showed a selective loss of dense-core granules in serglycin(-/-) CD8(+) CTLs, although other granule types were maintained quantitatively. The findings of the present study show that serglycin plays a critical role in the maturation of dense-core cytotoxic granules in cytotoxic lymphocytes and the trafficking and storage of perforin and granzyme B, whereas granzyme A is unaffected. The skewed retention of cytotoxic effector molecules markedly reduces CTL/NK cell cytotoxicity, although this is partly compensated for as a result of activating the cells by physiological means. PMID:26756195

  13. Cytotoxicity of CD56(bright NK cells towards autologous activated CD4+ T cells is mediated through NKG2D, LFA-1 and TRAIL and dampened via CD94/NKG2A.

    Directory of Open Access Journals (Sweden)

    Natasja Nielsen

    Full Text Available In mouse models of chronic inflammatory diseases, Natural Killer (NK cells can play an immunoregulatory role by eliminating chronically activated leukocytes. Indirect evidence suggests that NK cells may also be immunoregulatory in humans. Two subsets of human NK cells can be phenotypically distinguished as CD16(+CD56(dim and CD16(dim/-CD56(bright. An expansion in the CD56(bright NK cell subset has been associated with clinical responses to therapy in various autoimmune diseases, suggesting an immunoregulatory role for this subset in vivo. Here we compared the regulation of activated human CD4(+ T cells by CD56(dim and CD56(bright autologous NK cells in vitro. Both subsets efficiently killed activated, but not resting, CD4(+ T cells. The activating receptor NKG2D, as well as the integrin LFA-1 and the TRAIL pathway, played important roles in this process. Degranulation by NK cells towards activated CD4(+ T cells was enhanced by IL-2, IL-15, IL-12+IL-18 and IFN-α. Interestingly, IL-7 and IL-21 stimulated degranulation by CD56(bright NK cells but not by CD56(dim NK cells. NK cell killing of activated CD4(+ T cells was suppressed by HLA-E on CD4(+ T cells, as blocking the interaction between HLA-E and the inhibitory CD94/NKG2A NK cell receptor enhanced NK cell degranulation. This study provides new insight into CD56(dim and CD56(bright NK cell-mediated elimination of activated autologous CD4(+ T cells, which potentially may provide an opportunity for therapeutic treatment of chronic inflammation.

  14. Cytotoxicity of CD56(bright) NK cells towards autologous activated CD4+ T cells is mediated through NKG2D, LFA-1 and TRAIL and dampened via CD94/NKG2A.

    Science.gov (United States)

    Nielsen, Natasja; Ødum, Niels; Ursø, Birgitte; Lanier, Lewis L; Spee, Pieter

    2012-01-01

    In mouse models of chronic inflammatory diseases, Natural Killer (NK) cells can play an immunoregulatory role by eliminating chronically activated leukocytes. Indirect evidence suggests that NK cells may also be immunoregulatory in humans. Two subsets of human NK cells can be phenotypically distinguished as CD16(+)CD56(dim) and CD16(dim/-)CD56(bright). An expansion in the CD56(bright) NK cell subset has been associated with clinical responses to therapy in various autoimmune diseases, suggesting an immunoregulatory role for this subset in vivo. Here we compared the regulation of activated human CD4(+) T cells by CD56(dim) and CD56(bright) autologous NK cells in vitro. Both subsets efficiently killed activated, but not resting, CD4(+) T cells. The activating receptor NKG2D, as well as the integrin LFA-1 and the TRAIL pathway, played important roles in this process. Degranulation by NK cells towards activated CD4(+) T cells was enhanced by IL-2, IL-15, IL-12+IL-18 and IFN-α. Interestingly, IL-7 and IL-21 stimulated degranulation by CD56(bright) NK cells but not by CD56(dim) NK cells. NK cell killing of activated CD4(+) T cells was suppressed by HLA-E on CD4(+) T cells, as blocking the interaction between HLA-E and the inhibitory CD94/NKG2A NK cell receptor enhanced NK cell degranulation. This study provides new insight into CD56(dim) and CD56(bright) NK cell-mediated elimination of activated autologous CD4(+) T cells, which potentially may provide an opportunity for therapeutic treatment of chronic inflammation. PMID:22384114

  15. Natural killer cell cytotoxicity of breast cancer targets is enhanced by two distinct mechanisms of antibody-dependent cellular cytotoxicity against LFA-3 and HER2/neu.

    Science.gov (United States)

    Cooley, S; Burns, L J; Repka, T; Miller, J S

    1999-10-01

    Treatment of advanced breast cancer with autologous stem cell transplantation is limited by a high probability of disease relapse. In clinical trials, interleukin 2 (IL-2) alone can expand natural killer (NK) cells in vivo and increase their cytotoxic activity against breast cancer cell lines, but this increase is modest. Understanding the mechanisms that mediate NK cell lysis of breast cancer targets may lead to improvements of current immunotherapy strategies. NK cells from normal donors or patients receiving subcutaneous IL-2 were tested in cytotoxicity assays against five breast cancer cell lines. The role of adhesion molecules and antibodies that interact through Fc receptors on NK cells was explored. NK cell lysis of breast cancer targets is variable and is partially dependent on recognition through ICAM-1 and CD18. While blocking CD2 slightly decreased cytotoxicity, contrary to expectations, an antibody against CD58 (the ligand for CD2), failed to block killing and instead mediated an increased cytotoxicity that correlated with target density of CD58. The CD58 antibody-enhanced killing was dependent not only on FcRgammaIII but also on CD2 and ICAM-1/CD18. To further elucidate the mechanism of this CD58 antibody-dependent cellular cytotoxicity (ADCC), another antibody was tested. Trastuzumab (Herceptin), a humanized antibody against HER2/neu, mediated potent ADCC against all the HER2/neu positive breast cancer targets. Unlike CD58 antibody-mediated ADCC, Herceptin ADCC was minimally affected by blocking antibodies to CD2 or ICAM-1/CD18, which suggests a different mechanism of action. This study shows that multiple mechanisms are involved in NK cell lysis of breast cancer targets, that none of the targets are inherently resistant to killing, and that two distinct mechanisms of ADCC can target immunotherapy to breast cancer cells. PMID:10517495

  16. Regulation of IL-2 induced proliferation and cytotoxicity in human natural killer cells by monoclonal antibodies

    International Nuclear Information System (INIS)

    Natural killer (NK) activity is mediated by a subpopulation of cells termed large granular lymphocytes (LGL), which exhibit cytotoxic activity against a variety of tumor targets. LGL express OKT8, OKT9, OKT10, OKT11, 3G8 (FcγR), OKM1, NKH1. The addition of recombinant IL-2 (rIL-2), increases cytotoxicity, induces IFN-γ production and leads to LGL proliferation. Since monoclonal antibodies (MoAb) represent highly specific probes to analyze possible surface molecules, they have studied the role of various MoAbs in the regulation of cytotoxicity, proliferation, and secretory function of purified LGL. LGL were isolated from nonadherent human peripheral blood leukocytes on discontinuous Percoll density gradients, followed by 290C E-rosette depletion of contaminating T cells. These preparations were ≥ 85% LGL and contained ≥ 5% OKT3+ cells. Using a limiting dilution assay, purified LGL were incubated with rIL-2 and the MoAbs (10 μg/ml) for 7 days. These cells were tested for cytotoxicity against K562 in a 51Cr- release assay, and for proliferation as determined by 3H-thymidine incorporation. Results indicate that the OKT9 antibody inhibited both the cytotoxicity and proliferation. MoAb against LGl markers (OKT11, OKT8, OKM1, 3G8, and NKH1) had no effect on cytotoxicity or proliferation. Unlike the T cell receptor complex (with OKT3), the surface molecules examined do not regulate LGL lysis or proliferation

  17. Spontaneous and natural cytotoxicity receptor-mediated cytotoxicity are effector functions of distinct natural killer subsets in hepatitis C virus-infected chimpanzees.

    Science.gov (United States)

    Verstrepen, B E; Nieuwenhuis, I G; Mooij, P; Bogers, W M; Boonstra, A; Koopman, G

    2016-07-01

    In humans, CD16 and CD56 are used to identify functionally distinct natural killer (NK) subsets. Due to ubiquitous CD56 expression, this marker cannot be used to distinguish between NK cell subsets in chimpanzees. Therefore, functional analysis of distinct NK subsets during hepatitis C virus (HCV) infection has never been performed in these animals. In the present study an alternative strategy was used to identify four distinct NK subsets on the basis of the expression of CD16 and CD94. The expression of activating and inhibiting surface receptors showed that these subsets resemble human NK subsets. CD107 expression was used to determine degranulation of the different subsets in naive and HCV-infected chimpanzees. In HCV-infected chimpanzees increased spontaneous cytotoxicity was observed in CD94(high/dim) CD16(pos) and CD94(low) CD16(pos) subsets. By contrast, increased natural cytotoxicity receptor (NCR)- mediated degranulation after NKp30 and NKp44 triggering was demonstrated in the CD94(dim) CD16(neg) subset. Our findings suggest that spontaneous and NCR-mediated cytotoxicity are effector functions of distinct NK subsets in HCV-infected chimpanzees. PMID:26850369

  18. Cytotoxicity of bovine and porcine collagen membranes in mononuclear cells.

    Science.gov (United States)

    Moura, Camilla Christian Gomes; Soares, Priscilla Barbosa Ferreira; Carneiro, Karine Fernandes; Souza, Maria Aparecida de; Magalhães, Denildo

    2012-01-01

    This study compared the cytotoxicity and the release of nitric oxide induced by collagen membranes in human mononuclear cells. Peripheral blood was collected from each patient and the separation of mononuclear cells was performed by Ficoll. Then, 2x10(5) cells were plated in 48-well culture plates under the membranes in triplicate. The polystyrene surface was used as negative control. Cell viability was assessed by measuring mitochondrial activity (MTT) at 4, 12 and 24 h, with dosage levels of nitrite by the Griess method for the same periods. Data had non-normal distribution and were analyzed by the Kruskal-Wallis test (p<0.05). Statistically significant differences (p<0.05) were observed between the membranes and the control in the experimental period, although there was a significant reduction in viability over time (p<0.01). At 4 and 12 h, the porcine membrane induced a higher release of nitrite compared with the control and bovine membrane, respectively (p<0.01), and this difference was maintained at 24 h (p<0.05). This in vitro study showed that the porcine collagen membrane induces an increased production of proinflammatory mediators by mononuclear cells in the first hours of contact, decreasing with time. PMID:22460313

  19. Cytotoxicity and gene expression changes induced by inorganic and organic trivalent arsenicals in human cells

    International Nuclear Information System (INIS)

    Highlights: • Human urothelial, skin and bronchial epithelial cells treated with trivalent arsenicals. • Determined cytotoxicity (LC50) and gene expression changes. • Each trivlaent had LC50s at similar ranges in all the cell types. • Minor differences in gene expression changes observed between trivalent arsenicals. • Overall trivalent arsenicals induced similar gene changes between the cell types. - Abstract: Inorganic arsenic (iAs) is a human urinary bladder, skin and lung carcinogen. iAs is metabolized to methylated arsenicals, with trivalent arsenicals more cytotoxic than pentavalent forms in vitro. In this study, cytotoxicity and gene expression changes for arsenite (iAsIII), monomethylarsonous acid (MMAIII) and dimethylarsinous acid (DMAIII) were evaluated in three human cell types, urothelial (1T1), keratinocyte (HEK001) and bronchial epithelial (HBE) cells, corresponding to target organs for iAs-induced cancer. Cells were exposed to arsenicals to determine cytotoxicity and to study gene expression changes. Affymetrix chips were used to determine differentially expressed genes (DEGs) by statistical analysis. Lethal concentrations (LC50) for trivalent arsenicals in all cells ranged from 1.6 to 10 μM. MMAIII and DMAIII had 4–12-fold greater potency compared to iAs. Increasing concentrations of iAsIII induced more genes and additional signaling pathways in HBE cells. At equivalent cytotoxic concentrations, greater numbers of DEGs were induced in 1T1 cells compared to the other cells. Each arsenical altered slightly different signaling pathways within and between cell types, but when altered pathways from all three arsenicals were combined, they were similar between cell types. The major signaling pathways altered included NRF2-mediated stress response, interferon, p53, cell cycle regulation and lipid peroxidation. These results show a similar process qualitatively and quantitatively for all three cell types, and support a mode of action involving

  20. Uremic Toxins Enhance Statin-Induced Cytotoxicity in Differentiated Human Rhabdomyosarcoma Cells

    Directory of Open Access Journals (Sweden)

    Hitoshi Uchiyama

    2014-09-01

    Full Text Available The risk of myopathy and rhabdomyolysis is considerably increased in statin users with end-stage renal failure (ESRF. Uremic toxins, which accumulate in patients with ESRF, exert cytotoxic effects that are mediated by various mechanisms. Therefore, accumulation of uremic toxins might increase statin-induced cytotoxicity. The purpose of this study was to determine the effect of four uremic toxins—hippuric acid, 3-carboxy-4-methyl-5-propyl-2-furanpropionate, indole-3-acetic acid, and 3-indoxyl sulfate—on statin-induced myopathy. Differentiated rhabdomyosarcoma cells were pre-treated with the uremic toxins for seven days, and then the cells were treated with pravastatin or simvastatin. Cell viability and apoptosis were assessed by viability assays and flow cytometry. Pre-treatment with uremic toxins increased statin- but not cisplatin-induced cytotoxicity (p < 0.05 vs. untreated. In addition, the pre-treatment increased statin-induced apoptosis, which is one of the cytotoxic factors (p < 0.05 vs. untreated. However, mevalonate, farnesol, and geranylgeraniol reversed the effects of uremic toxins and lowered statin-induced cytotoxicity (p < 0.05 vs. untreated. These results demonstrate that uremic toxins enhance statin-induced apoptosis and cytotoxicity. The mechanism underlying this effect might be associated with small G-protein geranylgeranylation. In conclusion, the increased severity of statin-induced rhabdomyolysis in patients with ESRF is likely due to the accumulation of uremic toxins.

  1. Non-major histocompatibility complex-restricted cytotoxic activity of blood mononuclear cells stimulated with secreted mycobacterial proteins and other mycobacterial antigens

    DEFF Research Database (Denmark)

    Ravn, P; Pedersen, B K

    1994-01-01

    Several observations indicate that non-major histocompatibility complex (MHC)-restricted cytotoxicity, mediated for example by natural killer cells and lymphokine-activated killer cells, may serve as an important antimicrobial defense mechanism. The purpose of the present study was to investigate...... the influences of different mycobacterial antigens on non-MHC-restricted cytotoxicity and further to investigate the ways by which various lymphocyte subpopulations contribute to the development of this cytotoxicity. Non-MHC-restricted cytotoxicity was induced following stimulation of mononuclear...... interferon. The CD4+ cells proliferated and expressed interleukin-2 receptors following stimulation with mycobacterial antigens.Depletion studies after antigen stimulation showed that the cytotoxic effector cells were CD16+ CD56+ and CD4-; the CD4+ cells alone did not mediate non-MHC-restricted cytotoxicity...

  2. Cytotoxic activities of amentoflavone against human breast and cervical cancers are mediated by increasing of PTEN expression levels due to peroxisomes proliferate-activated receptor {gamma} activation

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Eunjung; Shin, Soyoung; Lee, Jeeyoung; Lee, So Jung; Kim, Jinkyoung; Yoon, Doyoung; Kim, Yangmee [Konkuk Univ., Seoul (Korea, Republic of); Woo, Eunrhan [Chosun Univ., Gwangju (Korea, Republic of)

    2012-07-15

    Human peroxisomes proliferate-activated receptor gamma (hPPAR{gamma}) has been implicated in numerous pathologies, including obesity, diabetes, and cancer. Previously, we verified that amentoflavone is an activator of hPPAR{gamma} and probed the molecular basis of its action. In this study, we investigated the mechanism of action of amentoflavone in cancer cells and demonstrated that amentoflavone showed strong cytotoxicity against MCF-7 and HeLa cancer cell lines. We showed that hPPAR{gamma} expression in MCF-7 and HeLa cells is specifically stimulated by amentoflavone, and suggested that amentoflavone-induced cytotoxic activities are mediated by activation of hPPAR{gamma} in these two cancer cell lines. Moreover, amentoflavone increased PTEN levels in these two cancer cell lines, indicating that the cytotoxic activities of amentoflavone are mediated by increasing of PTEN expression levels due to hPPAR{gamma} activation.

  3. Cytotoxic activities of amentoflavone against human breast and cervical cancers are mediated by increasing of PTEN expression levels due to peroxisomes proliferate-activated receptor γ activation

    International Nuclear Information System (INIS)

    Human peroxisomes proliferate-activated receptor gamma (hPPARγ) has been implicated in numerous pathologies, including obesity, diabetes, and cancer. Previously, we verified that amentoflavone is an activator of hPPARγ and probed the molecular basis of its action. In this study, we investigated the mechanism of action of amentoflavone in cancer cells and demonstrated that amentoflavone showed strong cytotoxicity against MCF-7 and HeLa cancer cell lines. We showed that hPPARγ expression in MCF-7 and HeLa cells is specifically stimulated by amentoflavone, and suggested that amentoflavone-induced cytotoxic activities are mediated by activation of hPPARγ in these two cancer cell lines. Moreover, amentoflavone increased PTEN levels in these two cancer cell lines, indicating that the cytotoxic activities of amentoflavone are mediated by increasing of PTEN expression levels due to hPPARγ activation

  4. Sex steroids do not affect shigatoxin cytotoxicity on human renal tubular or glomerular cells

    OpenAIRE

    Kohan Donald E; Schmid Douglas I; Hughes Alisa K

    2002-01-01

    Abstract Background The greater susceptibility of children to renal injury in post-diarrheal hemolytic-uremic syndrome (HUS) may be related, at least in part, to heightened renal cell sensitivity to the cytotoxic effect of Shiga toxin (Stx), the putative mediator of kidney damage in HUS. We hypothesized that sexual maturation, which coincides with a falling incidence of HUS, may induce a relatively Stx-resistant state in the renal cells. Methods Cultured human glomerular endothelial (HGEN), h...

  5. Xanthatin anti-tumor cytotoxicity is mediated via glycogen synthase kinase-3β and β-catenin.

    Science.gov (United States)

    Tao, Li; Sheng, Xiaobo; Zhang, Lei; Li, Weidong; Wei, Zhonghong; Zhu, Pinting; Zhang, Feng; Wang, Aiyun; Woodgett, James R; Lu, Yin

    2016-09-01

    Xanthatin, a xanthanolide sesquiterpene lactone isolated from Xanthium strumarium L. (Asteraceae), has prominent anti-tumor activity. Initial mechanism of action studies suggested xanthatin triggered activation of Wnt/β-catenin. We examined the effects of xanthatin on signaling pathways in A459 lung cancer cells and mouse embryonic fibroblasts to ascertain requirements for xanthatin-induced cell death and tumor growth in xenografts. Genetic inactivation of GSK-3β, but not the related isoform GSK-3α, compromised xanthatin cytotoxicity while inactivation of β-catenin enhanced xanthatin-mediated cell death. These data provide insight into how xanthatin and related molecules could be effectively targeted toward certain tumors. PMID:27321043

  6. Base excision by thymine DNA glycosylase mediates DNA-directed cytotoxicity of 5-fluorouracil.

    Directory of Open Access Journals (Sweden)

    Christophe Kunz

    2009-04-01

    Full Text Available 5-Fluorouracil (5-FU, a chemotherapeutic drug commonly used in cancer treatment, imbalances nucleotide pools, thereby favoring misincorporation of uracil and 5-FU into genomic DNA. The processing of these bases by DNA repair activities was proposed to cause DNA-directed cytotoxicity, but the underlying mechanisms have not been resolved. In this study, we investigated a possible role of thymine DNA glycosylase (TDG, one of four mammalian uracil DNA glycosylases (UDGs, in the cellular response to 5-FU. Using genetic and biochemical tools, we found that inactivation of TDG significantly increases resistance of both mouse and human cancer cells towards 5-FU. We show that excision of DNA-incorporated 5-FU by TDG generates persistent DNA strand breaks, delays S-phase progression, and activates DNA damage signaling, and that the repair of 5-FU-induced DNA strand breaks is more efficient in the absence of TDG. Hence, excision of 5-FU by TDG, but not by other UDGs (UNG2 and SMUG1, prevents efficient downstream processing of the repair intermediate, thereby mediating DNA-directed cytotoxicity. The status of TDG expression in a cancer is therefore likely to determine its response to 5-FU-based chemotherapy.

  7. Cytotoxic studies of paclitaxel (Taxol) in human tumour cell lines.

    OpenAIRE

    Liebmann, J. E.; Cook, J. A.; Lipschultz, C.; Teague, D.; Fisher, J; Mitchell, J B

    1993-01-01

    The cytotoxicity of paclitaxel against eight human tumour cell lines has been studied with in vitro clonogenic assays. The fraction of surviving cells fell sharply after exposure for 24 h to paclitaxel concentrations ranging from 2 to 20 nM; the paclitaxel IC50 was found to range between 2.5 and 7.5 nM. Increasing the paclitaxel concentration above 50 nM, however, resulted in no additional cytotoxicity after a 24 h drug exposure. Cells incubated in very high concentrations of paclitaxel (10,0...

  8. Analysis of the Effects of Cell Stress and Cytotoxicity on In Vitro Assay Activity Across a Diverse Chemical and Assay Space

    Science.gov (United States)

    Chemical toxicity can arise from disruption of specific biomolecular functions or through more generalized cell stress and cytotoxicity-mediated processes. Here, concentration-dependent responses of 1063 chemicals including pharmaceuticals, natural products, pesticidals, consumer...

  9. Bombesin receptor-mediated imaging and cytotoxicity: review and current status

    OpenAIRE

    Sancho, Veronica; Di Florio, Alessia; Moody, Terry W.; Jensen, Robert T.

    2011-01-01

    The three mammalian bombesin (Bn) receptors (gastrin-releasing peptide [GRP] receptor, neuromedin B [NMB] receptor, BRS-3) are one of the classes of G protein-coupled receptors that are most frequently over-express/ectopically expressed by common, important malignancies. Because of the clinical success of somatostatin receptor-mediated imaging and cytotoxicity with neuroendocrine...

  10. Unraveling the response of plant cells to cytotoxic saponins: Role of metallothionein and nitric oxide

    OpenAIRE

    Balestrazzi, Alma; Macovei, Anca; Tava, Aldo; Avato, Pinarosa; Raimondi, Elena; Daniela CARBONERA

    2011-01-01

    A wide range of pharmacological properties are ascribed to natural saponins, in addition to their biological activities against herbivores, plant soil-borne pathogens and pests. As for animal cells, the cytotoxicity and the chemopreventive role of saponins are mediated by a complex network of signal transduction pathways which include reactive oxygen species (ROS) and nitric oxide (NO). The involvement of other relevant components of the saponin-related signaling routes, such as the Tumor Nec...

  11. Cytotoxicity study of rock wool by cell magnetometric evaluation.

    Science.gov (United States)

    Kudo, Yuichiro; Kotani, Makoto; Aizawa, Yoshiharu

    2009-11-01

    The cytotoxicity of rock wool (RW), an asbestos substitute, was evaluated by cell magnetometry. Alveolar macrophages were isolated from male Fisher rats. Following addition of triiron tetraoxide (Fe(3)O(4)) to macrophages, RW was added. Then, the remnant magnetic field strength was measured for 20min after magnetization by an external field. Relaxation, an indicator of decay of cytotoxicity, was observed by cell magnetometry immediately postmagnetization in the group to which RW was added. In general, materials phagocytosed by macrophages are ingested into phagosomes and digested while migrating. This migration of phagosomes occurs by polymerization and depolymerization of the cytoskeleton. As a result of evaluation, relaxation was not delayed by addition of RW, since RW caused no effect on the cytoskeleton. It was suggested that RW has no cytotoxicity as evaluated by cell magnetometry. PMID:19559064

  12. The ROS-induced cytotoxicity of ascorbate is attenuated by hypoxia and HIF-1alpha in the NCI60 cancer cell lines

    OpenAIRE

    Sinnberg, Tobias; Noor, Seema; Venturelli, Sascha; Berger, Alexander; Schuler, Paul; Garbe, Claus; Busch, Christian

    2013-01-01

    Intravenous application of high-dose ascorbate is used in complementary palliative medicine to treat cancer patients. Pharmacological doses of ascorbate in the mM range induce cytotoxicity in cancer cells mediated by reactive oxygen species (ROS), namely hydrogen peroxide and ascorbyl radicals. However, little is known about intrinsic or extrinsic factors modulating this ascorbate-mediated cytotoxicity. Under normoxia and hypoxia, ascorbate IC50 values were determined on the NCI60 cancer cell...

  13. Cytotoxicity of luteolin in primary rat hepatocytes: the role of CYP3A-mediated ortho-benzoquinone metabolite formation and glutathione depletion.

    Science.gov (United States)

    Shi, Fuguo; Zhao, Peng; Li, Xiaobing; Pan, Hong; Ma, Shiping; Ding, Li

    2015-11-01

    Luteolin (LUT), an active ingredient in traditional Chinese medicines and an integral part of the human diet, has shown promising pharmacological activities with a great potential for clinical use. The purpose of this study was to evaluate the role of cytochrome P450 (CYP450)-mediated reactive ortho-benzoquinone metabolites formation and glutathione (GSH) depletion in LUT-induced cytotoxicity in primary rat hepatocytes. A reactive ortho-benzoquinone metabolite was identified by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) in rat liver microsomes (RLMs) and rat hepatocytes. Using a specific chemical inhibitor method, the CYP3A subfamily was found to be responsible for the reactive metabolite formation in RLMs. Induction of CYP3A by dexamethasone enhanced LUT-induced cytotoxicity, whereas inhibition of CYP3A by ketoconazole (Keto) decreased the cytotoxicity. The cytotoxicity and cell apoptosis induced by LUT were related to the amount of reactive metabolite formation. Furthermore, Keto inhibited the LUT-induced GSH exhaustion. The cytotoxicity was significantly enhanced by pretreatment with L-buthionine sulfoximine to deplete the intracellular GSH. A time course experiment showed that GSH depletion by LUT was not via oxidation of GSH and occurred prior to the increase in 2', 7'-dichlorofluorescein in hepatocytes. Collectively, these data suggest that CYP3A-mediated reactive metabolite formation plays a critical role in LUT-induced hepatotoxicity, and the direct GSH depletion is an initiating event in LUT-mediated cytotoxicity in primary rat hepatocytes. PMID:25612170

  14. Cytotoxicity of the saponin TTB2 on Ewing sarcoma cells

    OpenAIRE

    Huang, Wenfeng; Zou, Kun

    2015-01-01

    The steroidal saponin TTB2 can be isolated from the n-BuOH extracts of Trillium tschonoskii Maxim. The aim of the present study was to observe whether this saponin exerted any cytotoxic effects on malignant sarcoma cells, and to further investigate the possible underlying molecular mechanisms. The cell viability, cell cycle arrest and phosphorylation of certain important signal molecules in the sarcoma cell line were investigated. It was found that TTB2 inhibited the growth of the Ewing sarco...

  15. Evaluation of Cytotoxicity and Cell Death Induced In Vitro by Saxitoxin in Mammalian Cells.

    Science.gov (United States)

    Melegari, Silvia P; de Carvalho Pinto, Cátia R S; Moukha, Serge; Creppy, Edmond E; Matias, William G

    2015-01-01

    Since the cyanotoxin saxitoxin (STX) is a neurotoxin and induces ecological changes in aquatic environments, a potential risk to public and environmental health exists. However, data on STX-mediated cytotoxic and genotoxic effects are still scare. In order to gain a better understanding of the effects of this toxin, the cytotoxic and genotoxic potential of STX was examined in two mammalian cell lines. Neuro 2A (N2A), a neuroblastoma mouse cell line, and Vero cell line, derived from Vero green monkey kidney cells, were exposed to several concentrations of STX ranging from 0.5 to 64 nM to determine cell viability, induction of apoptosis (DNA fragmentation assay), and formation of micronuclei (MN) (cytokinesis-block micronucleus assay; CBMN) following 24 h of incubation. The half maximal effective concentration (EC50) values for STX calculated in cell viability tests were 1.01 nM for N2A and 0.82 nM for Vero cells. With increasing STX concentration there was evidence of DNA fragmentation indicating apoptosis induction in Vero cells with a 50% increase in DNA fragmentation compared to control at the highest STX concentration tested (3 nM). The results demonstrated no significant changes in the frequency of micronucleated binucleated cells in N2A and Vero cells exposed to STX, indicating the absence of genotoxicity under these test conditions. There was no apparent cellular necrosis as evidenced by a lack of formation of multinucleated cells. In conclusion, data reported herein demonstrate that STX produced death of both cell types tested through an apoptotic process. PMID:26436995

  16. Cytotoxicity of polycyclic nitroaromatic hydrocarbons to rat tracheal epithelial cells

    International Nuclear Information System (INIS)

    Four nitropolycyclic aromatic hydrocarbons (HPAH) were investigated for their cytotoxic effects on rat tracheal epithelial (RTE) cells. 6-Nitrochrysene (6-NC), 1,6-dinitropyrene (1,6-DNP), 1-nitropyrene (1-NP), and 4-nitropyrene (4-NP) induced dose dependent decreases in the relative colony-forming efficiency (RCFE) of RTE cells. The compounds could be separated into two groups based on the magnitude of their cytotoxic effects, a highly cytotoxic group (6-NC and 1,6-DNP), and a group with low cytotoxicity (1-NP nd 4-NP). The most cytotoxic compound was 6-NC, with an ED50 of 0.13 μM, followed by 1,6-DNP, 4-NP, and 1-NP with ED50s of 1.24 μM, 8.9 μM, and 9.1 μM, respectively. These studies show that RTE cells have the metabolic capacity to activate NAPH to toxic metabolites and should be very useful for evaluating the potential toxic effects of this ubiquitous class of airborne pollutants. (author)

  17. Cell cooperation in coelomocyte cytotoxic activity of Paracentrotus lividus coelomocytes.

    Science.gov (United States)

    Arizza, Vincenzo; Giaramita, Francesca Tiziana; Parrinello, Daniela; Cammarata, Matteo; Parrinello, Nicolò

    2007-06-01

    The coelomic fluid from the sea urchin Paracentrotus lividus contains several coelomocyte types including amoebocytes and uncoloured spherulocytes involved in immune defences. In the present paper, we show a Ca(2+)-dependent cytotoxic activity for the unfractionated coelomocytes assayed in vitro, with rabbit erythrocytes and the K562 tumour cell line. In a plaque-forming assay, whole coelomocyte preparations as well as density gradient separated coelomocyte populations revealed that cell populations enriched in uncoloured spherulocytes, exerted high cytotoxic activity by releasing lysins in the presence of amoebocytes. This cooperative effect could be dependent on soluble factors released by amoebocytes. With regard to this, we show that an enhanced cytotoxic activity was found by adding the supernatant from sonicated amoebocytes or hemocyte culture medium into spherulocyte preparations. PMID:17329136

  18. Microchip screening platform for single cell assessment of NK cell cytotoxicity

    Directory of Open Access Journals (Sweden)

    Karolin eGuldevall

    2016-04-01

    Full Text Available Here we report a screening platform for assessment of the cytotoxic potential of individual natural killer (NK cells within larger populations. Human primary NK cells were distributed across a silicon-glass microchip containing 32 400 individual microwells loaded with target cells. Through fluorescence screening and automated image analysis the numbers of NK and live or dead target cells in each well could be assessed at different time points after initial mixing. Cytotoxicity was also studied by time-lapse live-cell imaging in microwells quantifying the killing potential of individual NK cells. Although most resting NK cells (≈75% were non-cytotoxic against the leukemia cell line K562, some NK cells were able to kill several (≥3 target cells within the 12 hours long experiment. In addition, the screening approach was adapted to increase the chance to find and evaluate serial killing NK cells. Even if the cytotoxic potential varied between donors it was evident that a small fraction of highly cytotoxic NK cells were responsible for a substantial portion of the killing. We demonstrate multiple assays where our platform can be used to enumerate and characterize cytotoxic cells, such as NK or T cells. This approach could find use in clinical applications, e.g. in the selection of donors for stem cell transplantation or generation of highly specific and cytotoxic cells for adoptive immunotherapy.

  19. Nanomaterial cytotoxicity is composition, size, and cell type dependent

    Directory of Open Access Journals (Sweden)

    Sohaebuddin Syed K

    2010-08-01

    Full Text Available Abstract Background Despite intensive research efforts, reports of cellular responses to nanomaterials are often inconsistent and even contradictory. Additionally, relationships between the responding cell type and nanomaterial properties are not well understood. Using three model cell lines representing different physiological compartments and nanomaterials of different compositions and sizes, we have systematically investigated the influence of nanomaterial properties on the degrees and pathways of cytotoxicity. In this study, we selected nanomaterials of different compositions (TiO2 and SiO2 nanoparticles, and multi-wall carbon nanotubes [MWCNTs] with differing size (MWCNTs of different diameters 50 nm; but same length 0.5-2 μm to analyze the effects of composition and size on toxicity to 3T3 fibroblasts, RAW 264.7 macrophages, and telomerase-immortalized (hT bronchiolar epithelial cells. Results Following characterization of nanomaterial properties in PBS and serum containing solutions, cells were exposed to nanomaterials of differing compositions and sizes, with cytotoxicity monitored through reduction in mitochondrial activity. In addition to cytotoxicity, the cellular response to nanomaterials was characterized by quantifying generation of reactive oxygen species, lysosomal membrane destabilization and mitochondrial permeability. The effect of these responses on cellular fate - apoptosis or necrosis - was then analyzed. Nanomaterial toxicity was variable based on exposed cell type and dependent on nanomaterial composition and size. In addition, nanomaterial exposure led to cell type dependent intracellular responses resulting in unique breakdown of cellular functions for each nanomaterial: cell combination. Conclusions Nanomaterials induce cell specific responses resulting in variable toxicity and subsequent cell fate based on the type of exposed cell. Our results indicate that the composition and size of nanomaterials as well as the

  20. Evaluation of cell cytotoxic effect on herbal extracts mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yong Soo; Gwon, Hui Jeong; Choi, Bo Ram; Lim, Youn Mook; Nho, Young Chang [Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of)

    2009-12-15

    Herbal extracts (HE) such as Houttuynia cordata Thunb., Eucommia ulimoides, Plantago asiatica var., Morus alba L., and Ulmus davidiana var., are known to suppress an atopic dermatitis like skin lesions. In this study, to evaluate the cell cytotoxicity effect on L929, HaCaT and HMC-1 cell by the HE, the herbs were extracted with distilled water (at 75 .deg. C) and then the HE mixtures were freeze-dried for 5 days and sterilized with {gamma}-rays. The cytotoxicity was measured by Cell Counting Kit-8 (CCK-8) assay. The result showed that the HE mixtures did not significantly affect cell viability and had no toxicity on the cells. These findings indicate that the HE mixtures can be used as a potential therapeutic agent.

  1. Impaired cytotoxicity associated with defective natural killer cell differentiation in myelodysplastic syndromes.

    Science.gov (United States)

    Hejazi, Maryam; Manser, Angela R; Fröbel, Julia; Kündgen, Andrea; Zhao, Xiaoyi; Schönberg, Kathrin; Germing, Ulrich; Haas, Rainer; Gattermann, Norbert; Uhrberg, Markus

    2015-05-01

    Natural killer cells are well known to mediate anti-leukemic responses in myeloid leukemia but their role in myelodysplastic syndromes is not well understood. Here, in a cohort of newly diagnosed patients (n=75), widespread structural and functional natural killer cell defects were identified. One subgroup of patients (13%) had a selective deficiency of peripheral natural killer cells (count <10/mm(3) blood) with normal frequencies of T and natural killer-like T cells. Natural killer cell-deficient patients were predominantly found in high-risk subgroups and deficiency of these cells was significantly associated with poor prognosis. In the second subgroup, comprising the majority of patients (76%), natural killer cells were present but exhibited poor cytotoxicity. The defect was strongly associated with reduced levels of perforin and granzyme B. Notably, natural killer cell function and arming of cytotoxic granules could be fully reconstituted by in vitro stimulation. Further phenotypic analysis of these patients revealed an immature natural killer cell compartment that was biased towards CD56(bright) cells. The residual CD56(dim) cells exhibited a significant increase of the unlicensed NKG2A(-)KIR(-) subset and a striking reduction in complexity of the repertoire of killer cell immunoglobulin-like receptors. Taken together, these results suggest that the widespread defects in natural killer cell function occurring in patients with myelodysplastic syndromes are mostly due to either unsuccessful or inefficient generation of mature, functionally competent natural killer cells, which might contribute to disease progression through impaired immune surveillance. PMID:25682594

  2. Virus-specific HLA-restricted lysis of herpes simplex virus-infected human monocytes and macrophages mediated by cytotoxic T lymphocytes

    International Nuclear Information System (INIS)

    Freshly-isolated peripheral blood human monocytes and 5 day in vitro cultured macrophages were infected with herpes simplex virus type 1 (HSV-1), labeled with 51Cr, and used as target cells in a 12-14 hour cell-mediated cytotoxicity assay. Mononuclear leukocytes (MNL) from HSV-1 non-immune individuals, whether unstimulated or stimulated with HSV-1 antigen, did not mediate significant lysis of either target cell. HSV-immune MNL, both freshly-isolated and cultured for 5 days without antigen, demonstrated only low levels of natural killer (NK) cell-mediate lysis. MNL from HSV-immune individuals incubated for 5 days in vitro with HSV-1 antigen mediated significant virus-specific lysis of both target cells. Mean virus-specific lysis of autologous monocytes was 8.5(/+-/2.0)% compared to a three-fold greater virus-specific lysis of autologous macrophages. Greater than 70% of this lytic activity was mediated by Leu-11-negative, T3-positive cytotoxic T lymphocytes (CTL). Allogeneic target cells lacking a common HLA determinant were not significantly lysed while T8-positive CTL mediated infrequent lysis of target cells sharing a common HLA-A and/or HLA-B determinant. T4-positive lymphocytes were demonstrated to be the predominant cell mediating lysis of autologous target cells and allogeneic target cells sharing both HLA-A and/or HLA-B plus HLA-DR determinants with the CTL; the T4-positive cell was the sole CTL mediator of lysis of allogeneic target cells having a common HLA-DR determinant

  3. Listeriolysin O mediates cytotoxicity against human brain microvascular

    Science.gov (United States)

    Penetration of the brain microvascular endothelial layer is one of the routes L. monocytogenes use to breach the blood-brain barrier. Because host factors in the blood severely limit direct invasion of human brain microvascular endothelial cells (HBMECs) by L. monocytogenes, alternative mechanisms m...

  4. Impact of polysialylated CD56 on natural killer cell cytotoxicity

    Directory of Open Access Journals (Sweden)

    Kaltschmidt Christian

    2007-08-01

    Full Text Available Abstract Background Siglec-7, a sialic acid binding inhibitory receptor expressed by NK cells is masked in vivo by a so far unknown ligand. It shows a strong binding prevalence for α-2,8-linked disialic acids in vitro. Results Here we describe the expression of PSA-NCAM (α-2,8-linked polysialic acid modified NCAM on functional adult peripheral blood natural killer cells and examine its possible role in masking Siglec-7. Unmasking of Siglec-7 using Clostridium perfringens neuraminidase massively reduces NK cell cytotoxicity. By contrast a specific removal of PSA using Endo-NF does not lead to a reduction of NK cell cytotoxicity. Conclusion The results presented here therefore indicate that PSA-NCAM is not involved in masking Siglec-7.

  5. Cambogin is preferentially cytotoxic to cells expressing PDGFR.

    Directory of Open Access Journals (Sweden)

    Ze Tian

    Full Text Available Platelet-derived growth factor receptors (PDGFRs have been implicated in a wide array of human malignancies, including medulloblastoma (MB, the most common brain tumor of childhood. Although significant progress in MB biology and therapeutics has been achieved during the past decades, MB remains a horrible challenge to the physicians and researchers. Therefore, novel inhibitors targeting PDGFR signaling pathway may offer great promise for the treatment of MB. In the present study, we investigated the cytotoxicity and mechanisms of cambogin in Daoy MB cells. Our results show that cambogin triggers significant S phase cell cycle arrest and apoptosis via down regulation of cyclin A and E, and activation of caspases. More importantly, further mechanistic studies demonstrated that cambogin inhibits PDGFR signaling in Daoy and genetically defined mouse embryo fibroblast (MEF cell lines. These results suggest that cambogin is preferentially cytotoxic to cells expressing PDGFR. Our findings may provide a novel approach by targeting PDGFR signaling against MB.

  6. Idarubicin induces mTOR-dependent cytotoxic autophagy in leukemic cells

    International Nuclear Information System (INIS)

    We investigated if the antileukemic drug idarubicin induces autophagy, a process of programmed cellular self-digestion, in leukemic cell lines and primary leukemic cells. Transmission electron microscopy and acridine orange staining demonstrated the presence of autophagic vesicles and intracellular acidification, respectively, in idarubicin-treated REH leukemic cell line. Idarubicin increased punctuation/aggregation of microtubule-associated light chain 3B (LC3B), enhanced the conversion of LC3B-I to autophagosome-associated LC3B-II in the presence of proteolysis inhibitors, and promoted the degradation of the selective autophagic target p62, thus indicating the increase in autophagic flux. Idarubicin inhibited the phosphorylation of the main autophagy repressor mammalian target of rapamycin (mTOR) and its downstream target p70S6 kinase. The treatment with the mTOR activator leucine prevented idarubicin-mediated autophagy induction. Idarubicin-induced mTOR repression was associated with the activation of the mTOR inhibitor AMP-activated protein kinase and down-regulation of the mTOR activator Akt. The suppression of autophagy by pharmacological inhibitors or LC3B and beclin-1 genetic knockdown rescued REH cells from idarubicin-mediated oxidative stress, mitochondrial depolarization, caspase activation and apoptotic DNA fragmentation. Idarubicin also caused mTOR inhibition and cytotoxic autophagy in K562 leukemic cell line and leukocytes from chronic myeloid leukemia patients, but not healthy controls. By demonstrating mTOR-dependent cytotoxic autophagy in idarubicin-treated leukemic cells, our results warrant caution when considering combining idarubicin with autophagy inhibitors in leukemia therapy. - Highlights: • Idarubicin induces autophagy in leukemic cell lines and primary leukemic cells. • Idarubicin induces autophagy by inhibiting mTOR in leukemic cells. • mTOR suppression by idarubicin is associated with AMPK activation and Akt blockade.

  7. Idarubicin induces mTOR-dependent cytotoxic autophagy in leukemic cells

    Energy Technology Data Exchange (ETDEWEB)

    Ristic, Biljana [Institute of Microbiology and Immunology, School of Medicine, University of Belgrade, Dr. Subotica 1, 11000 Belgrade (Serbia); Bosnjak, Mihajlo [Institute of Histology and Embryology, School of Medicine, University of Belgrade, Belgrade (Serbia); Arsikin, Katarina [Institute of Microbiology and Immunology, School of Medicine, University of Belgrade, Dr. Subotica 1, 11000 Belgrade (Serbia); Mircic, Aleksandar; Suzin-Zivkovic, Violeta [Institute of Histology and Embryology, School of Medicine, University of Belgrade, Belgrade (Serbia); Bogdanovic, Andrija [Clinic for Hematology, Clinical Centre of Serbia, School of Medicine, University of Belgrade, Belgrade (Serbia); Perovic, Vladimir [Institute of Microbiology and Immunology, School of Medicine, University of Belgrade, Dr. Subotica 1, 11000 Belgrade (Serbia); Martinovic, Tamara; Kravic-Stevovic, Tamara; Bumbasirevic, Vladimir [Institute of Histology and Embryology, School of Medicine, University of Belgrade, Belgrade (Serbia); Trajkovic, Vladimir, E-mail: vtrajkovic@med.bg.ac.rs [Institute of Microbiology and Immunology, School of Medicine, University of Belgrade, Dr. Subotica 1, 11000 Belgrade (Serbia); Harhaji-Trajkovic, Ljubica, E-mail: buajk@yahoo.com [Institute for Biological Research, University of Belgrade, Belgrade, Despot Stefan Blvd. 142, 11000 Belgrade (Serbia)

    2014-08-01

    We investigated if the antileukemic drug idarubicin induces autophagy, a process of programmed cellular self-digestion, in leukemic cell lines and primary leukemic cells. Transmission electron microscopy and acridine orange staining demonstrated the presence of autophagic vesicles and intracellular acidification, respectively, in idarubicin-treated REH leukemic cell line. Idarubicin increased punctuation/aggregation of microtubule-associated light chain 3B (LC3B), enhanced the conversion of LC3B-I to autophagosome-associated LC3B-II in the presence of proteolysis inhibitors, and promoted the degradation of the selective autophagic target p62, thus indicating the increase in autophagic flux. Idarubicin inhibited the phosphorylation of the main autophagy repressor mammalian target of rapamycin (mTOR) and its downstream target p70S6 kinase. The treatment with the mTOR activator leucine prevented idarubicin-mediated autophagy induction. Idarubicin-induced mTOR repression was associated with the activation of the mTOR inhibitor AMP-activated protein kinase and down-regulation of the mTOR activator Akt. The suppression of autophagy by pharmacological inhibitors or LC3B and beclin-1 genetic knockdown rescued REH cells from idarubicin-mediated oxidative stress, mitochondrial depolarization, caspase activation and apoptotic DNA fragmentation. Idarubicin also caused mTOR inhibition and cytotoxic autophagy in K562 leukemic cell line and leukocytes from chronic myeloid leukemia patients, but not healthy controls. By demonstrating mTOR-dependent cytotoxic autophagy in idarubicin-treated leukemic cells, our results warrant caution when considering combining idarubicin with autophagy inhibitors in leukemia therapy. - Highlights: • Idarubicin induces autophagy in leukemic cell lines and primary leukemic cells. • Idarubicin induces autophagy by inhibiting mTOR in leukemic cells. • mTOR suppression by idarubicin is associated with AMPK activation and Akt blockade.

  8. Phototoxicity and cytotoxicity of fullerol in human lens epithelial cells

    International Nuclear Information System (INIS)

    The water-soluble, hydroxylated fullerene [fullerol, nano-C60(OH)22-26] has several clinical applications including use as a drug carrier to bypass the blood ocular barriers. We have assessed fullerol's potential ocular toxicity by measuring its cytotoxicity and phototoxicity induced by UVA and visible light in vitro with human lens epithelial cells (HLE B-3). Accumulation of nano-C60(OH)22-26 in the cells was confirmed spectrophotometrically at 405 nm and cell viability estimated using MTS and LDH assays. Fullerol was cytotoxic to HLE B-3 cells maintained in the dark at concentrations higher than 20 μM. Exposure to either UVA or visible light in the presence of > 5 μM fullerol-induced phototoxic damage. When cells were pretreated with non-toxic antioxidants: 20 μM lutein, 1 mM N-acetyl cysteine, or 1 mM L-ascorbic acid prior to irradiation, only the singlet oxygen quencher-lutein significantly protected against fullerol photodamage. Apoptosis was observed in lens cells treated with fullerol whether or not the cells were irradiated, in the order UVA > visible light > dark. Dynamic light scattering (DLS) showed that in the presence of the endogenous lens protein α-crystallin, large aggregates of fullerol were reduced. In conclusion, fullerol is both cytotoxic and phototoxic to human lens epithelial cells. Although the acute toxicity of water-soluble nano-C60(OH)22-26 is low, these compounds are retained in the body for long periods, raising concern for their chronic toxic effect. Before fullerols are used to deliver drugs to the eye, they should be tested for photo- and cytotoxicity in vivo

  9. Sex steroids do not affect shigatoxin cytotoxicity on human renal tubular or glomerular cells

    Directory of Open Access Journals (Sweden)

    Kohan Donald E

    2002-08-01

    Full Text Available Abstract Background The greater susceptibility of children to renal injury in post-diarrheal hemolytic-uremic syndrome (HUS may be related, at least in part, to heightened renal cell sensitivity to the cytotoxic effect of Shiga toxin (Stx, the putative mediator of kidney damage in HUS. We hypothesized that sexual maturation, which coincides with a falling incidence of HUS, may induce a relatively Stx-resistant state in the renal cells. Methods Cultured human glomerular endothelial (HGEN, human glomerular visceral epithelial (HGEC and human proximal tubule (HPT cells were exposed to Stx-1 after pre-incubation with progesterone, β-estradiol or testosterone followed by determination of cytotoxicity. Results Under basal conditions, Stx-1 potently and dose-dependently killed HPT and HGEC, but had relatively little effect on HGEN. Pre-incubation for 1, 2 or 7 days with physiologic or pharmacologic concentrations of progesterone, β-estradiol or testosterone had no effect on Stx-1 cytotoxicity dose-response on any cell type. In addition, no steroid altered Gb3 expression (Stx receptor by any cell type at any time point. Conclusion These data do not support the notion that hormonal changes associated with puberty induce an Stx-resistant state within kidney cells.

  10. Chaperone protein HYPK interacts with the first 17 amino acid region of Huntingtin and modulates mutant HTT-mediated aggregation and cytotoxicity

    International Nuclear Information System (INIS)

    Highlights: • HYPK reduces mutant HTT-mediated aggregate formation and cytotoxicity. • Interaction of HYPK with HTT requires N-terminal 17 amino acid of HTT (HTT-N17). • Deletion of HTT-N17 leads to SDS-soluble, smaller, nuclear aggregates. • These smaller aggregates do not associate with HYPK and are more cytotoxic. • Maybe, interaction of HYPK with amphipathic HTT-N17 block HTT aggregate formation. - Abstract: Huntington’s disease is a polyglutamine expansion disorder, characterized by mutant HTT-mediated aggregate formation and cytotoxicity. Many reports suggests roles of N-terminal 17 amino acid domain of HTT (HTT-N17) towards subcellular localization, aggregate formation and subsequent pathogenicity induced by N-terminal HTT harboring polyQ stretch in pathogenic range. HYPK is a HTT-interacting chaperone which can reduce N-terminal mutant HTT-mediated aggregate formation and cytotoxicity in neuronal cell lines. However, how HYPK interacts with N-terminal fragment of HTT remained unknown. Here we report that specific interaction of HYPK with HTT-N17 is crucial for the chaperone activity of HYPK. Deletion of HTT-N17 leads to formation of tinier, SDS-soluble nuclear aggregates formed by N-terminal mutant HTT. The increased cytotoxicity imparted by these tiny aggregates might be contributed due to loss of interaction with HYPK

  11. Chaperone protein HYPK interacts with the first 17 amino acid region of Huntingtin and modulates mutant HTT-mediated aggregation and cytotoxicity

    Energy Technology Data Exchange (ETDEWEB)

    Choudhury, Kamalika Roy [Crystallography and Molecular Biology Division, Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata 700064 (India); Centre for Neuroscience, Indian Institute of Science, Bangalore 560012 (India); Bhattacharyya, Nitai P., E-mail: nitai_sinp@yahoo.com [Biomedical Genomics Centre, PG Polyclinic Building, 5, Suburbun Hospital Road, Kolkata 700020 (India)

    2015-01-02

    Highlights: • HYPK reduces mutant HTT-mediated aggregate formation and cytotoxicity. • Interaction of HYPK with HTT requires N-terminal 17 amino acid of HTT (HTT-N17). • Deletion of HTT-N17 leads to SDS-soluble, smaller, nuclear aggregates. • These smaller aggregates do not associate with HYPK and are more cytotoxic. • Maybe, interaction of HYPK with amphipathic HTT-N17 block HTT aggregate formation. - Abstract: Huntington’s disease is a polyglutamine expansion disorder, characterized by mutant HTT-mediated aggregate formation and cytotoxicity. Many reports suggests roles of N-terminal 17 amino acid domain of HTT (HTT-N17) towards subcellular localization, aggregate formation and subsequent pathogenicity induced by N-terminal HTT harboring polyQ stretch in pathogenic range. HYPK is a HTT-interacting chaperone which can reduce N-terminal mutant HTT-mediated aggregate formation and cytotoxicity in neuronal cell lines. However, how HYPK interacts with N-terminal fragment of HTT remained unknown. Here we report that specific interaction of HYPK with HTT-N17 is crucial for the chaperone activity of HYPK. Deletion of HTT-N17 leads to formation of tinier, SDS-soluble nuclear aggregates formed by N-terminal mutant HTT. The increased cytotoxicity imparted by these tiny aggregates might be contributed due to loss of interaction with HYPK.

  12. Protection from Ebola Virus Mediated by Cytotoxic T Lymphocytes Specific for the Viral Nucleoprotein

    OpenAIRE

    Wilson, Julie A.; Hart, Mary Kate

    2001-01-01

    Cytotoxic T lymphocytes (CTLs) are proposed to be critical for protection from intracellular pathogens such as Ebola virus. However, there have been no demonstrations that protection against Ebola virus is mediated by Ebola virus-specific CTLs. Here, we report that C57BL/6 mice vaccinated with Venezuelan equine encephalitis virus replicons encoding the Ebola virus nucleoprotein (NP) survived lethal challenge with Ebola virus. Vaccination induced both antibodies to the NP and a major histocomp...

  13. Oxygen dependence of human alveolar macrophage-mediated antibody-dependent cytotoxicity.

    OpenAIRE

    Conkling, P.; Papermaster-Bender, G; Whitcomb, M; Sagone, A L

    1982-01-01

    We studied the metabolic characteristics of the human alveolar macrophage-mediated antibody-dependent cytotoxicity (ADCC) reaction, using an anti-D sensitized human erythrocyte target system. Metabolic experiments demonstrated a high resting rate of glucose metabolism in macrophages, but no oxidative metabolic burst was found to accompany the ADCC reaction. These findings were confirmed by oxygen consumption studies, showing a high resting rate of oxygen consumption by macrophages, but no cha...

  14. Cytotoxicity and Effects on Cell Viability of Nickel Nanowires

    KAUST Repository

    Rodriguez, Jose E.

    2013-05-01

    Recently, magnetic nanoparticles are finding an increased use in biomedical applications and research. Nanobeads are widely used for cell separation, biosensing and cancer therapy, among others. Due to their properties, nanowires (NWs) are gaining ground for similar applications and, as with all biomaterials, their cytotoxicity is an important factor to be considered before conducting biological studies with them. In this work, the cytotoxic effects of nickel NWs (Ni NWs) were investigated in terms of cell viability and damage to the cellular membrane. Ni NWs with an average diameter of 30-34 nm were prepared by electrodeposition in nanoporous alumina templates. The templates were obtained by a two-step anodization process with oxalic acid on an aluminum substrate. Characterization of NWs was done using X-Ray diffraction (XRD) and energy dispersive X-Ray analysis (EDAX), whereas their morphology was observed with scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Cell viability studies were carried out on human colorectal carcinoma cells HCT 116 by the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) cell proliferation colorimetric assay, whereas the lactate dehydrogenase (LDH) homogenous membrane fluorimetric assay was used to measure the degree of cell membrane rupture. The density of cell seeding was calculated to obtain a specific cell number and confluency before treatment with NWs. Optical readings of the cell-reduced MTT products were measured at 570 nm, whereas fluorescent LDH membrane leakage was recorded with an excitation wavelength of 525 nm and an emission wavelength of 580 - 640 nm. The effects of NW length, cell exposure time, as well as NW:cell ratio, were evaluated through both cytotoxic assays. The results show that cell viability due to Ni NWs is affected depending on both exposure time and NW number. On the other hand, membrane rupture and leakage was only significant at later exposure times. Both

  15. "Proliferation of cytotoxic and activated T cells during acute Epstein-Barr virus induced Infectious Mononucleosis "

    Directory of Open Access Journals (Sweden)

    Mansoori SD

    2002-05-01

    Full Text Available The immune responses that develop following Epstien-Barr Virus (EBV infection are complex and involve both humoral and to a greater extent cell-mediated immune mechanisms. To evaluate the immune response, flow cytometric analysis of the peripheral blood of six patients during the acute phase of EBV infection was performed. This analysis revealed a significant increase in the percentages and the absolute number of CD8+cytotoxic and activated (HLA-DR+ - T lymphocytes and in some cases with a concomitan decrease in the percentages of B (CD19+ lymphocytes and T helper (CD4+ lymphocytes. These patient invariably had inverted CD4/CD8 ratio. All changes reversed to normal level during the recovery phase of infection. It is therefore concluded that EBV specific cytotoxic and activated T lymphocytes are essential in controlling acute EBV infection presented by the infected B cells.

  16. Investigation of the cytotoxicity of CCVD carbon nanotubes towards human umbilical vein endothelial cells

    OpenAIRE

    Flahaut, Emmanuel; Durrieu, Marie-Christine; Remy-Zolghadri, Murielle; Bareille, Reine; Baquey, Charles

    2006-01-01

    The cytotoxicity of different samples of carbon nanotubes synthesised by catalytic chemical vapour deposition was investigated towards human umbilical vein endothelial cells, using two cytotoxicity standard assays (neutral red assay for the cell viability and MTT assay—tetrazolinium salt—for the cell metabolic activity). No cytotoxicity was found for any sample.

  17. Cytotoxicity and glutathione depletion studies using CHOK cells

    International Nuclear Information System (INIS)

    Radiosensitization characteristics of newly synthesized isoindole-4, 7-diones have been established in the authors' laboratories. Cytotoxicity studies of isoindole-4, 7-diones on chinese hamster ovary cell (CHOK) have been carried out. The effects that different concentrations of isoindole-4, 7-diones have on cell growth as a function of time after treatment on both systems (oxic and hypoxic) have been determined. Most of isoindole-4, 7-diones used in these studies show more cytotoxic effect under hypoxic conditions. Gluthathione depletion was also measured in both systems. Most of the quinones studied deplete the concentration of glutathione in the CHOK cells. The results will be compared with similar studies carried out with the well known radiosensitizers misonidazole. It is hoped that the isoindole-r, 7-diones are a new family of chemical radiosensitizers

  18. Salinomycin induces selective cytotoxicity to MCF-7 mammosphere cells through targeting the Hedgehog signaling pathway.

    Science.gov (United States)

    Fu, Ying-Zi; Yan, Yuan-Yuan; He, Miao; Xiao, Qing-Huan; Yao, Wei-Fan; Zhao, Lin; Wu, Hui-Zhe; Yu, Zhao-Jin; Zhou, Ming-Yi; Lv, Mu-Tian; Zhang, Shan-Shan; Chen, Jian-Jun; Wei, Min-Jie

    2016-02-01

    Breast cancer stem cells (BCSCs) are believed to be responsible for tumor chemoresistance, recurrence, and metastasis formation. Salinomycin (SAL), a carboxylic polyether ionophore, has been reported to act as a selective breast CSC inhibitor. However, the molecular mechanisms underlying SAL-induced cytotoxicity on BCSCs remain unclear. The Hedgehog (Hh) signaling pathway plays an important role in CSC maintenance and carcinogenesis. Here, we investigated whether SAL induces cytotoxicity on BCSCs through targeting Hh pathway. In the present study, we cultured breast cancer MCF-7 cells in suspension in serum-free medium to obtain breast CSC-enriched MCF-7 mammospheres (MCF-7 MS). MCF-7 MS cells possessed typical BCSC properties, such as CD44+CD24-/low phenotype, high expression of OCT4 (a stem cell marker), increased colony-forming ability, strong migration and invasion capabilities, differentiation potential, and strong tumorigenicity in xenografted mice. SAL exhibited selective cytotoxicity to MCF-7 MS cells relative to MCF-7 cells. The Hh pathway was highly activated in BCSC-enriched MCF-7 MS cells and SAL inhibited Hh signaling activation by downregulating the expression of critical components of the Hh pathway such as PTCH, SMO, Gli1, and Gli2, and subsequently repressing the expression of their essential downstream targets including C-myc, Bcl-2, and Snail (but not cyclin D1). Conversely, Shh-induced Hh signaling activation could largely reverse SAL-mediated inhibitory effects. These findings suggest that SAL-induced selective cytotoxicity against MCF-7 MS cells is associated with the inhibition of Hh signaling activation and the expression of downstream targets and the Hh pathway is an important player and a possible drug target in the pathogenesis of BCSCs. PMID:26718029

  19. Gangliosides inhibit bee venom melittin cytotoxicity but not phospholipase A2-induced degranulation in mast cells

    International Nuclear Information System (INIS)

    Sting accident by honeybee causes severe pain, inflammation and allergic reaction through IgE-mediated anaphylaxis. In addition to this hypersensitivity, an anaphylactoid reaction occurs by toxic effects even in a non-allergic person via cytolysis followed by similar clinical manifestations. Auto-injectable epinephrine might be effective for bee stings, but cannot inhibit mast cell lysis and degranulation by venom toxins. We used connective tissue type canine mast cell line (CM-MC) for finding an effective measure that might inhibit bee venom toxicity. We evaluated degranulation and cytotoxicity by measurement of β-hexosaminidase release and MTT assay. Melittin and crude bee venom induced the degranulation and cytotoxicity, which were strongly inhibited by mono-sialoganglioside (GM1), di-sialoganglioside (GD1a) and tri-sialoganglioside (GT1b). In contrast, honeybee venom-derived phospholipase A2 induced the net degranulation directly without cytotoxicity, which was not inhibited by GM1, GD1a and GT1b. For analysis of distribution of Gαq and Gαi protein by western blotting, lipid rafts were isolated by using discontinuous sucrose gradient centrifuge. Melittin disrupted the localization of Gαq and Gαi at lipid raft, but gangliosides stabilized the rafts. As a result from this cell-based study, bee venom-induced anaphylactoid reaction can be explained with melittin cytotoxicity and phospholipase A2-induced degranulation. Taken together, gangliosides inhibit the effect of melittin such as degranulation, cytotoxicity and lipid raft disruption but not phospholipase A2-induced degranulation in mast cells. Our study shows a potential of gangliosides as a therapeutic tool for anaphylactoid reaction by honeybee sting.

  20. Cytotoxicity of CD56bright NK cells towards autologous activated CD4+ T cells is mediated through NKG2D, LFA-1 and TRAIL and dampened via CD94/NKG2A

    OpenAIRE

    Nielsen, Natasja; Ødum, Niels; Ursø, Birgitte; Lanier, Lewis L; Spee, Pieter

    2012-01-01

    In mouse models of chronic inflammatory diseases, Natural Killer (NK) cells can play an immunoregulatory role by eliminating chronically activated leukocytes. Indirect evidence suggests that NK cells may also be immunoregulatory in humans. Two subsets of human NK cells can be phenotypically distinguished as CD16(+)CD56(dim) and CD16(dim/-)CD56(bright). An expansion in the CD56(bright) NK cell subset has been associated with clinical responses to therapy in various autoimmune diseases, suggest...

  1. Cytotoxicity of CD56bright NK Cells towards Autologous Activated CD4+ T Cells Is Mediated through NKG2D, LFA-1 and TRAIL and Dampened via CD94/NKG2A

    OpenAIRE

    Natasja Nielsen; Niels Ødum; Birgitte Ursø; Lanier, Lewis L; Pieter Spee

    2012-01-01

    In mouse models of chronic inflammatory diseases, Natural Killer (NK) cells can play an immunoregulatory role by eliminating chronically activated leukocytes. Indirect evidence suggests that NK cells may also be immunoregulatory in humans. Two subsets of human NK cells can be phenotypically distinguished as CD16(+)CD56(dim) and CD16(dim/-)CD56(bright). An expansion in the CD56(bright) NK cell subset has been associated with clinical responses to therapy in various autoimmune diseases, suggest...

  2. Cytotoxicity of CD56bright NK cells towards autologous activated CD4+ T cells is mediated through NKG2D, LFA-1 and TRAIL and dampened via CD94/NKG2A

    DEFF Research Database (Denmark)

    Nielsen, Natasja; Ødum, Niels; Ursø, Birgitte;

    2012-01-01

    4(+) T cells by CD56(dim) and CD56(bright) autologous NK cells in vitro. Both subsets efficiently killed activated, but not resting, CD4(+) T cells. The activating receptor NKG2D, as well as the integrin LFA-1 and the TRAIL pathway, played important roles in this process. Degranulation by NK cells...... distinguished as CD16(+)CD56(dim) and CD16(dim/-)CD56(bright). An expansion in the CD56(bright) NK cell subset has been associated with clinical responses to therapy in various autoimmune diseases, suggesting an immunoregulatory role for this subset in vivo. Here we compared the regulation of activated human CD...... towards activated CD4(+) T cells was enhanced by IL-2, IL-15, IL-12+IL-18 and IFN-α. Interestingly, IL-7 and IL-21 stimulated degranulation by CD56(bright) NK cells but not by CD56(dim) NK cells. NK cell killing of activated CD4(+) T cells was suppressed by HLA-E on CD4(+) T cells, as blocking...

  3. Effects of Ginkgo biloba extract on cell proliferation and cytotoxicity in human hepatocellular carcinoma cells

    OpenAIRE

    Chao, Jane CJ; Chu, Chia Chou

    2004-01-01

    AIM: To study the effect of Ginkgo biloba extract (EGb 761) containing 22%-27% flavonoids (ginkgo-flavone glycosides) and 5%-7% terpenoids (ginkgolides and bilobalides) on cell proliferation and cytotoxicity in human hepatocellular carcinoma (HCC) cells.

  4. Selective cytotoxicity of benzyl isothiocyanate in the proliferating fibroblastoid cells.

    Science.gov (United States)

    Miyoshi, Noriyuki; Uchida, Koji; Osawa, Toshihiko; Nakamura, Yoshimasa

    2007-02-01

    In the present study, experiments using presynchronization culture cells demonstrated that benzyl ITC (BITC), previously isolated from a tropical papaya fruit extract, induced the cytotoxic effect preferentially in the proliferating human colon CCD-18Co cells to the quiescent ones. Quiescent CCD-18Co cells were virtually unaffected by BITC and marginal cytotoxicity was observed at 15 microM. We observed that BITC dramatically induced the p53 phosphorylation and stabilization only in the quiescent (G(0)/G(1) phase-arrested) cells, but not significantly in the proliferating human colon CCD-18Co cells when compared with quiescent ones. We also observed ataxia telangiectasia-mutated (ATM) phosphorylation in the quiescent cells. The BITC-induced p53 phosphorylation was counteracted by caffeine treatment, implying the involvement of an ATM/ataxia telangiectasia and Rad3-related kinase signaling pathway. Moreover, downregulation of p53 by a siRNA resulted in the enhancement of susceptibility to undergo apoptosis by BITC. We also showed here that depletion of p53 abrogated G(0)/G(1) arrest accompanied by the declined expression of p21(waf1/cip1) and p27(kip1) in CCD-18Co cells. In conclusion, we identified p53 as a potential negative regulator of the apoptosis induction by BITC in the normal colon CCD-18Co cells through the inhibition of cell-cycle progression at the G(0)/G(1) phase. PMID:17096346

  5. Defective cell mediated immunity in sarcoidosis: effect of interleukin-2.

    OpenAIRE

    Lyons, D J; Gao, L.; Mitchell, E B; Mitchell, D. N.

    1988-01-01

    Interleukin-2 has been reported to enhance the immune response in diseases characterised by defective cell mediated immunity. The effect of exogenous recombinant interleukin-2 was studied on the proliferative and cytotoxic responses of peripheral blood mononuclear cells from 39 patients with sarcoidosis and 14 healthy control subjects. The proliferative response to purified protein derivative was smaller in patients than in control subjects (p less than 0.001) whereas the response to 80 U int...

  6. Hexavalent chromium is cytotoxic and genotoxic to American alligator cells.

    Science.gov (United States)

    Wise, Sandra S; Wise, Catherine; Xie, Hong; Guillette, Louis J; Zhu, Cairong; Wise, John Pierce; Wise, John Pierce

    2016-02-01

    Metals are a common pollutant in the aquatic ecosystem. With global climate change, these levels are anticipated to rise as lower pH levels allow sediment bound metals to be released. The American alligator (Alligator mississippiensis) is an apex predator in the aquatic ecosystem and is considered a keystone species; as such it serves as a suitable monitor for localized pollution. One metal of increasing concern is hexavalent chromium (Cr(VI)). It is present in the aquatic environment and is a known human carcinogen and reproductive toxicant. We measured the cytotoxicity and genotoxicity of Cr(VI) in American alligator cells derived from scute tissue. We found that particulate and soluble Cr(VI) are both cytotoxic and genotoxic to alligator cells in a concentration-dependent manner. These data suggest that alligators may be used as a model for assessing the effects of environmental Cr(VI) contamination as well as for other metals of concern. PMID:26730726

  7. Clonal Expansion and Cytotoxicity of TCRVβ Subfamily T Cells Induced by CML and K562 Cells

    Institute of Scientific and Technical Information of China (English)

    YupingZHang; YangqiuLi; ShaohuaChen; LijianYang; GengxinLuo; XueliZhang

    2004-01-01

    OBJECTIVE To investigate the anti-leukemia effect, the distribution and clonal expansion of TCRVβ subfamily T cells in T cells from cord blood and adult peripheral blood induced by CML cells and K562 cells in vitro. METHODS Peripheral blood T cells from one adult donor and 3 cases of cord blood were stimulated with CML cells and K562 cells and further amplified by a suspended T cell-bulk culture,in order to induce CML specific cytotoxic T lymphocytes. The induced T cells were further analyzed for the specific cytotoxicity in CML by LDH assay, the phenotype identification by indirect immunofiuorescence technique and the distribution and clonal expansion of TCRVβ subfamily by using reverse transcriptase-polymerase chain reaction (RT-PCR) and genescan analysis, respectively. RESULTS Oligoclonal and oligoclonal tendency T cells with higher specific cytotoxicity from cord blood and adult peripheral blood could be induced by stimulation with CML cells and K562 cells. CONCLUSIONS Specific cytotoxic T cells for an anti-CML effect could be induced by CML cells and K562 cells .The induced T cells which have the characteristic of specific cytotoxicity against CML cells may come from the clonal expansion of TCRVβ subfamily T cells.

  8. Rapid bioreduction of trivalent aurum using banana stem powder and its cytotoxicity against MCF-7 and HEK-293 cell lines

    International Nuclear Information System (INIS)

    Bioreduction of metal ions for the synthesis of nanoparticles of well-defined shape and size has been a great challenge in the field of nanotechnology. In this study, we explored the reduction potential of banana stem powder (BSP) for the synthesis of gold nanoparticles (GNP). The kinetics of GNP synthesis was monitored using UV–Vis spectroscopy. The synthesized GNP was characterized using dynamic light scattering (DLS), transmission electron microscopy, and fourier transform infrared spectroscopy. In addition, the cytotoxic potential of the synthesized GNP was investigated using human breast cancer (MCF-7) and normal human embryonic kidney (HEK-293) cell lines, as evaluated by changes in cell morphology, cell viability (MTT), and metabolic activity. BSP exhibited a strong reduction of Au(III) to Au (0) at room temperature within 5 min of reaction time. The synthesized GNP was found to be spherical with an average diameter of 30 nm by DLS analysis. The cytotoxicity analysis reveals a direct dose–response relationship, indicating that the cytotoxicity increases with increasing concentrations of the GNP. Significant cytotoxicity was observed in cancer cells (MCF-7) compared to normal cells (HEK-293). Also the cellular uptake of GNP was more pronounced in MCF-7 cells than HEK-293 cells as evidenced by zeta potential, implicating the possible reason for differential cytotoxicity. Thus the present study demonstrates the importance of these unique, less time-consuming, and stable BSP-mediated GNP as potential drug delivery vehicles in the application of anticancer therapy.

  9. Rapid bioreduction of trivalent aurum using banana stem powder and its cytotoxicity against MCF-7 and HEK-293 cell lines

    Energy Technology Data Exchange (ETDEWEB)

    Arunkumar, Pichaimani [Bharathidasan University, Cancer Genetics and Nanomedicine Laboratory, Department of Biomedical Science, School of Basic Medical Sciences (India); Vedagiri, Hemamalini [Bharathidasan University, Department of Biotechnology (India); Premkumar, Kumpati, E-mail: pkumpati@hotmail.com [Bharathidasan University, Cancer Genetics and Nanomedicine Laboratory, Department of Biomedical Science, School of Basic Medical Sciences (India)

    2013-03-15

    Bioreduction of metal ions for the synthesis of nanoparticles of well-defined shape and size has been a great challenge in the field of nanotechnology. In this study, we explored the reduction potential of banana stem powder (BSP) for the synthesis of gold nanoparticles (GNP). The kinetics of GNP synthesis was monitored using UV-Vis spectroscopy. The synthesized GNP was characterized using dynamic light scattering (DLS), transmission electron microscopy, and fourier transform infrared spectroscopy. In addition, the cytotoxic potential of the synthesized GNP was investigated using human breast cancer (MCF-7) and normal human embryonic kidney (HEK-293) cell lines, as evaluated by changes in cell morphology, cell viability (MTT), and metabolic activity. BSP exhibited a strong reduction of Au(III) to Au (0) at room temperature within 5 min of reaction time. The synthesized GNP was found to be spherical with an average diameter of 30 nm by DLS analysis. The cytotoxicity analysis reveals a direct dose-response relationship, indicating that the cytotoxicity increases with increasing concentrations of the GNP. Significant cytotoxicity was observed in cancer cells (MCF-7) compared to normal cells (HEK-293). Also the cellular uptake of GNP was more pronounced in MCF-7 cells than HEK-293 cells as evidenced by zeta potential, implicating the possible reason for differential cytotoxicity. Thus the present study demonstrates the importance of these unique, less time-consuming, and stable BSP-mediated GNP as potential drug delivery vehicles in the application of anticancer therapy.

  10. Assay of mast cell mediators

    DEFF Research Database (Denmark)

    Rådinger, Madeleine; Jensen, Bettina M; Swindle, Emily;

    2015-01-01

    Mediator release from activated mast cells is a major initiator of the symptomology associated with allergic disorders such as anaphylaxis and asthma. Thus, methods to monitor the generation and release of such mediators have widespread applicability in studies designed to understand the processe...

  11. Rational Development of a Cytotoxic Peptide to Trigger Cell Death

    OpenAIRE

    Boohaker, Rebecca J.; Zhang, Ge; Lee, Michael W; Nemec, Kathleen N.; Santra, Santimukul; Perez, J Manuel; Khaled, Annette R.

    2012-01-01

    Defects in the apoptotic machinery can contribute to tumor formation and resistance to treatment, creating a need to identify new agents that kill cancer cells by alternative mechanisms. To this end, we examined the cytotoxic properties of a novel peptide, CT20p, derived from the C-terminal, alpha-9 helix of Bax, an amphipathic domain with putative membrane binding properties. Like many anti-microbial peptides, CT20p contains clusters of hydrophobic and cationic residues that could enable the...

  12. Hypoxia-inducible miR-210 regulates the susceptibility of tumor cells to lysis by cytotoxic T cells.

    Science.gov (United States)

    Noman, Muhammad Zaeem; Buart, Stéphanie; Romero, Pedro; Ketari, Sami; Janji, Bassam; Mari, Bernard; Mami-Chouaib, Fathia; Chouaib, Salem

    2012-09-15

    Hypoxia in the tumor microenvironment plays a central role in the evolution of immune escape mechanisms by tumor cells. In this study, we report the definition of miR-210 as a miRNA regulated by hypoxia in lung cancer and melanoma, documenting its involvement in blunting the susceptibility of tumor cells to lysis by antigen-specific cytotoxic T lymphocytes (CTL). miR-210 was induced in hypoxic zones of human tumor tissues. Its attenuation in hypoxic cells significantly restored susceptibility to autologous CTL-mediated lysis, independent of tumor cell recognition and CTL reactivity. A comprehensive approach using transcriptome analysis, argonaute protein immunoprecipitation, and luciferase reporter assay revealed that the genes PTPN1, HOXA1, and TP53I11 were miR-210 target genes regulated in hypoxic cells. In support of their primary importance in mediating the immunosuppressive effects of miR-210, coordinate silencing of PTPN1, HOXA1, and TP53I11 dramatically decreased tumor cell susceptibility to CTL-mediated lysis. Our findings show how miR-210 induction links hypoxia to immune escape from CTL-mediated lysis, by providing a mechanistic understanding of how this miRNA mediates immunosuppression in oxygen-deprived regions of tumors where cancer stem-like cells and metastatic cellular behaviors are known to evolve. PMID:22962263

  13. Glycan elongation beyond the mucin associated Tn antigen protects tumor cells from immune-mediated killing

    DEFF Research Database (Denmark)

    Madsen, Caroline B; Lavrsen, Kirstine; Steentoft, Catharina; Vester-Christensen, Malene B; Clausen, Henrik; Wandall, Hans H; Pedersen, Anders Elm

    2013-01-01

    recognized as cancer associated truncated glycans, and are expressed in many adenocarcinomas, e.g. breast- and pancreatic cancer cells. To investigate the role of the cancer associated glycan truncations in immune-mediated killing we created glyco-engineered breast- and pancreatic cancer cells expressing...... and pancreatic cancer cell lines T47D and Capan-1 increases sensitivity to both NK cell mediated antibody-dependent cellular-cytotoxicity (ADCC) and cytotoxic T lymphocyte (CTL)-mediated killing. In addition, we investigated the association between total cell surface expression of MUC1/MUC16 and NK or...... CTL mediated killing, and observed an inverse correlation between MUC16/MUC1 expression and the sensitivity to ADCC and CTL-mediated killing. Together, these data suggest that up-regulation of membrane bound mucins protects cells from immune mediated killing, and that particular glycosylation steps...

  14. ZINC-mediated gene expression offers protection against H2O2-induced cytotoxicity

    International Nuclear Information System (INIS)

    The ability of zinc to mobilize defense against reactive oxygen species (ROS) and H2O2-induced apoptosis was studied using a primary culture of rainbow trout gill cells. Gill cells were pretreated for 24 h with 100 μM ZnSO4 followed by 24-h exposure to 100 or 200 μM H2O2, or were subjected to 100 μM ZnSO4 together with 100 or 200 μM H2O2. Metallothionein-A (MTA) and metallothionein-B (MTB) mRNA levels were increased after treatment with zinc or H2O2, separately or in combination. Similarly, mRNA for glutathione S-transferase (GST) and glucose 6-phosphate dehydrogenase (G6PD) were increased in response to either zinc or H2O2, or after sequential treatments with zinc followed by H2O2. The stimulatory effects of zinc or H2O2 on MTA, MTB, GST, and G6PD mRNA levels could be blocked by addition of the membrane permeable zinc chelator, N,N,N',N'-tetrakis(2-pyridylmethyl)ethylenediamine (TPEN), suggesting that H2O2-induced upregulation of these genes is zinc-dependent. Pretreatment with zinc protected the cells from subsequent cell damage and apoptosis, as assessed by lactate dehydrogenase leakage, mitochondrial dehydrogenase activity (MTT assay), caspase-3 activity, and DNA fragmentation. In contrast, when gill cells were coincubated with zinc and H2O2 at the same time, H2O2 toxicity was higher than after treatment with H2O2 alone. It is concluded that zinc had a direct pro-oxidant effect when administered together with H2O2, but that pretreatment of zinc inhibited cytotoxicity and apoptosis through an indirect antioxidant action. We propose that the antioxidant action is manifested through zinc-dependent expression of several genes encoding antioxidant proteins (e.g., MTA, MTB, G6PD, and GST). Furthermore, the apparent zinc-dependency of H2O2-induced expression of antioxidant genes suggests that zinc might act as a physiological signal to mediate the response to oxidative stress

  15. Cytotoxicity of modified glass ionomer cement on odontoblast cells.

    Science.gov (United States)

    Chen, Song; Mestres, Gemma; Lan, Weihua; Xia, Wei; Engqvist, Håkan

    2016-07-01

    Recently a modified glass ionomer cement (GIC) with enhanced bioactivity due to the incorporation of wollastonite or mineral trioxide aggregate (MTA) has been reported. The aim of this study was to evaluate the cytotoxic effect of the modified GIC on odontoblast-like cells. The cytotoxicity of a conventional GIC, wollastonite modified GIC (W-mGIC), MTA modified GIC (M-mGIC) and MTA cement has been evaluated using cement extracts, a culture media modified by the cement. Ion concentration and pH of each material in the culture media were measured and correlated to the results of the cytotoxicity study. Among the four groups, conventional GIC showed the most cytotoxicity effect, followed by W-mGIC and M-mGIC. MTA showed the least toxic effect. GIC showed the lowest pH (6.36) while MTA showed the highest (8.62). In terms of ion concentration, MTA showed the largest Ca(2+) concentration (467.3 mg/L) while GIC showed the highest concentration of Si(4+) (19.9 mg/L), Al(3+) (7.2 mg/L) and Sr(2+) (100.3 mg/L). Concentration of F(-) was under the detection limit (0.02 mg/L) for all samples. However the concentrations of these ions are considered too low to be toxic. Our study showed that the cytotoxicity of conventional GIC can be moderated by incorporating calcium silicate based ceramics. The modified GIC might be promising as novel dental restorative cements. PMID:27221819

  16. Photopolymerization of cell-encapsulating hydrogels: crosslinking efficiency versus cytotoxicity.

    Science.gov (United States)

    Mironi-Harpaz, Iris; Wang, Dennis Yingquan; Venkatraman, Subbu; Seliktar, Dror

    2012-05-01

    Cell-encapsulating hydrogels used in regenerative medicine are designed to undergo a rapid liquid-to-solid phase transition in the presence of cells and tissues so as to maximize crosslinking and minimize cell toxicity. Light-activated free-radical crosslinking (photopolymerization) is of particular interest in this regard because it can provide rapid reaction rates that result in uniform hydrogel properties with excellent temporal and spatial control features. Among the many initiator systems available for photopolymerization, only a few have been identified as suitable for cell-based hydrogel formation owing to their water solubility, crosslinking properties and non-toxic reaction conditions. In this study, three long-wave ultraviolet (UV) light-activtied photoinitiators (PIs) were comparatively tested in terms of cytotoxicity, crosslinking efficiency and crosslinking kinetics of cell-encapsulating hydrogels. The hydrogels were photopolymerized from poly(ethylene glycol) (PEG) diacrylate or PEG-fibrinogen precursors using Irgacure® PIs I2959, I184 and I651, as well as with a chemical initiator/accelerator (APS/TEMED). The study specifically evaluated the PI type, PI concentration and UV light intensity, and how these affected the mechanical properties of the hydrogel (i.e. maximum storage modulus), the crosslinking reaction times and the reaction's cytotoxicity to encapsulated cells. Only two initiators (I2959 and I184) were identified as being suitable for achieving both high cell viability and efficient crosslinking of the cell-encapsulating hydrogels during the photopolymerization reaction. Optimization of PI concentration or irradiation intensity was particularly important for achieving maximum mechanical properties; a sub-optimal choice of PI concentration or irradiation intensity resulted in a substantial reduction in hydrogel modulus. Cytocompatibility may be compromised by unnecessarily prolonging exposure to cytotoxic free radicals or inadvertently

  17. α-Mangostin Enhances Betulinic Acid Cytotoxicity and Inhibits Cisplatin Cytotoxicity on HCT 116 Colorectal Carcinoma Cells

    Directory of Open Access Journals (Sweden)

    Amin Malik Shah Abdul Majid

    2012-03-01

    Full Text Available Despite the progress in colon cancer treatment, relapse is still a major obstacle. Hence, new drugs or drug combinations are required in the battle against colon cancer. α-Mangostin and betulinic acid (BA are cytotoxic compounds that work by inducing the mitochondrial apoptosis pathway, and cisplatin is one of the most potent broad spectrum anti-tumor agents. This study aims to investigate the enhancement of BA cytotoxicity by α-mangostin, and the cytoprotection effect of α-mangostin and BA on cisplatin-induced cytotoxicity on HCT 116 human colorectal carcinoma cells. Cytotoxicity was investigated by the XTT cell proliferation test, and the apoptotic effects were investigated on early and late markers including caspases-3/7, mitochondrial membrane potential, cytoplasmic shrinkage, and chromatin condensation. The effect of α-mangostin on four signalling pathways was also investigated by the luciferase assay. α-Mangostin and BA were more cytotoxic to the colon cancer cells than to the normal colonic cells, and both compounds showed a cytoprotective effect against cisplatin-induced cytotoxicity. On the other hand, α-mangostin enhanced the cytotoxic and apoptotic effects of BA. Combination therapy hits multiple targets, which may improve the overall response to the treatment, and may reduce the likelihood of developing drug resistance by the tumor cells. Therefore, α-mangostin and BA may provide a novel combination for the treatment of colorectal carcinoma. The cytoprotective effect of the compounds against cisplatin-induced cytotoxicity may find applications as chemopreventive agents against carcinogens, irradiation and oxidative stress, or to neutralize cisplatin side effects.

  18. Molecular basis of arsenite (As+3-induced acute cytotoxicity in human cervical epithelial carcinoma cells

    Directory of Open Access Journals (Sweden)

    Muhammad Nauman Arshad

    2015-04-01

    Full Text Available Background: Rapid industrialization is discharging toxic heavy metals into the environment, disturbing human health in many ways and causing various neurologic, cardiovascular, and dermatologic abnormalities and certain types of cancer. The presence of arsenic in drinking water from different urban and rural areas of the major cities of Pakistan, for example, Lahore, Faisalabad, and Kasur, was found to be beyond the permissible limit of 10 parts per billion set by the World Health Organization. Therefore the present study was initiated to examine the effects of arsenite (As+3 on DNA biosynthesis and cell death. Methods: After performing cytotoxic assays on a human epithelial carcinoma cell line, expression analysis was done by quantitative polymerase chain reaction, western blotting, and flow cytometry. Results: We show that As+3 ions have a dose- and time-dependent cytotoxic effect through the activation of the caspase-dependent apoptotic pathway. In contrast to previous research, the present study was designed to explore the early cytotoxic effects produced in human cells during exposure to heavy dosage of As+3 (7.5 µg/ml. Even treatment for 1 h significantly increased the mRNA levels of p21 and p27 and caspases 3, 7, and 9. It was interesting that there was no change in the expression levels of p53, which plays an important role in G2/M phase cell cycle arrest. Conclusion: Our results indicate that sudden exposure of cells to arsenite (As+3 resulted in cytotoxicity and mitochondrial-mediated apoptosis resulting from up-regulation of caspases.

  19. Zinc inhibits aflatoxin B1-induced cytotoxicity and genotoxicity in human hepatocytes (HepG2 cells).

    Science.gov (United States)

    Yang, Xuan; Lv, Yangjun; Huang, Kunlun; Luo, Yunbo; Xu, Wentao

    2016-06-01

    Aflatoxin B1 (AFB1) has strong carcinogenicity. Consumption of AFB1-contaminated agricultural products and the occurrence of hepatocellular carcinoma have received widespread attention. The aim of this paper was to investigate whether zinc supplementation could inhibit AFB1-induced cytotoxicity and genotoxicity in HepG2 cells and the mechanism of this inhibition. Our data suggest that zinc sources can relieve a certain degree of AFB1-induced cytotoxicity and genotoxicity by protecting against apoptotic body formation and DNA strand breaks, affecting S phase cell cycle arrest, reducing 8-OHdG formation, inhibiting global DNA hypomethylation and regulating gene expression in antioxidation, zinc-association and apoptosis processes. Consequently, zinc stabilizes the integrity of DNA and improves cell survival. These data provides new insights into the protective role of zinc in alleviating AFB1-induced cytotoxicity and mediating epigenetic changes in hepatocytes, demonstrating that zinc sources have detoxification properties in mycotoxin-induced toxicity. PMID:27017951

  20. Isoeugenol is a selective potentiator of camptothecin cytotoxicity in vertebrate cells lacking TDP1.

    Science.gov (United States)

    Elsayed, Waheba; El-Shafie, Lamia; Hassan, Mohamed K; Farag, Mohamed A; El-Khamisy, Sherif F

    2016-01-01

    Camptothecin (CPT), a topoisomerase I (TOP1) inhibitor, exhibits anti-tumor activity against a wide range of tumors. Redundancy of TOP1-mediated repair mechanisms is a major challenge facing the efficiency of TOP1-targetting therapies. This study aims to uncover new TOP1 targeting approaches utilising a selection of natural compounds in the presence or absence of tyrosyl DNA phosphodiesterase I (TDP1); a key TOP1-mediated protein-linked DNA break (PDB) repair enzyme. We identify, isoeugenol, a phenolic ether found in plant essential oils, as a potentiator of CPT cytotoxicity in Tdp1 deficient but not proficient cells. Consistent with our cellular data, isoeugenol did not inhibit Tdp1 enzymatic activity in vitro nor it sensitized cells to the PARP1 inhibitor olaparib. However, biochemical analyses suggest that isoeugenol inhibits TDP2 catalytic activity; a pathway that can compensate for the absence of TDP1. Consistent with this, isoeugenol exacerbated etoposide-induced cytotoxicity, which generates TOP2-mediated PDBs for which TDP2 is required for processing. Together, these findings identify isoeugenol as a potential lead compound for developing TDP2 inhibitors and encourage structure-activity relationship studies to shed more light on its utility in drug discovery programs. PMID:27220325

  1. Isoeugenol is a selective potentiator of camptothecin cytotoxicity in vertebrate cells lacking TDP1

    Science.gov (United States)

    Elsayed, Waheba; El-Shafie, Lamia; Hassan, Mohamed K.; Farag, Mohamed A.; El-Khamisy, Sherif F.

    2016-01-01

    Camptothecin (CPT), a topoisomerase I (TOP1) inhibitor, exhibits anti-tumor activity against a wide range of tumors. Redundancy of TOP1-mediated repair mechanisms is a major challenge facing the efficiency of TOP1-targetting therapies. This study aims to uncover new TOP1 targeting approaches utilising a selection of natural compounds in the presence or absence of tyrosyl DNA phosphodiesterase I (TDP1); a key TOP1-mediated protein-linked DNA break (PDB) repair enzyme. We identify, isoeugenol, a phenolic ether found in plant essential oils, as a potentiator of CPT cytotoxicity in Tdp1 deficient but not proficient cells. Consistent with our cellular data, isoeugenol did not inhibit Tdp1 enzymatic activity in vitro nor it sensitized cells to the PARP1 inhibitor olaparib. However, biochemical analyses suggest that isoeugenol inhibits TDP2 catalytic activity; a pathway that can compensate for the absence of TDP1. Consistent with this, isoeugenol exacerbated etoposide-induced cytotoxicity, which generates TOP2-mediated PDBs for which TDP2 is required for processing. Together, these findings identify isoeugenol as a potential lead compound for developing TDP2 inhibitors and encourage structure-activity relationship studies to shed more light on its utility in drug discovery programs. PMID:27220325

  2. Evidence for a new segregant series of B cell antigens that are encoded in the HLA-D region and that stimulate secondary allogenic proliferative and cytotoxic responses

    OpenAIRE

    1980-01-01

    Five new histocompatibility antigens, designated secondary B cell or (SB) antigens, have been identified by secondary allogeneic proliferative and cytotoxic responses. The reagents used to define the SB antigents are lymphocytes primed between donors matched for all known HLA antigens. The SB antigens stimulate weak primary allogeneic proliferative responses (a mean relative response of 8%) but strong secondary proliferative responses. Strong secondary cell-mediated cytotoxicity is generated ...

  3. A chimeric fusion of the hASH1 and EZH2 promoters mediates high and specific reporter and suicide gene expression and cytotoxicity in small cell lung cancer cells

    DEFF Research Database (Denmark)

    Poulsen, T.T.; Pedersen, N.; Juel, H.;

    2008-01-01

    Transcriptionally targeted gene therapy is a promising experimental modality for treatment of systemic malignancies such as small cell lung cancer (SCLC). We have identified the human achaete-scute homolog 1 (hASH1) and enhancer of zeste homolog 2 (EZH2) genes as highly upregulated in SCLC compared...

  4. Cytotoxicity of synthetic cannabinoids on primary neuronal cells of the forebrain: the involvement of cannabinoid CB{sub 1} receptors and apoptotic cell death

    Energy Technology Data Exchange (ETDEWEB)

    Tomiyama, Ken-ichi; Funada, Masahiko, E-mail: mfunada@ncnp.go.jp

    2014-01-01

    The abuse of herbal products containing synthetic cannabinoids has become an issue of public concern. The purpose of this paper was to evaluate the acute cytotoxicity of synthetic cannabinoids on mouse brain neuronal cells. Cytotoxicity induced by synthetic cannabinoid (CP-55,940, CP-47,497, CP-47,497-C8, HU-210, JWH-018, JWH-210, AM-2201, and MAM-2201) was examined using forebrain neuronal cultures. These synthetic cannabinoids induced cytotoxicity in the forebrain cultures in a concentration-dependent manner. The cytotoxicity was suppressed by preincubation with the selective CB{sub 1} receptor antagonist AM251, but not with the selective CB{sub 2} receptor antagonist AM630. Furthermore, annexin-V-positive cells were found among the treated forebrain cells. Synthetic cannabinoid treatment induced the activation of caspase-3, and preincubation with a caspase-3 inhibitor significantly suppressed the cytotoxicity. These synthetic cannabinoids induced apoptosis through a caspase-3-dependent mechanism in the forebrain cultures. Our results indicate that the cytotoxicity of synthetic cannabinoids towards primary neuronal cells is mediated by the CB{sub 1} receptor, but not by the CB{sub 2} receptor, and further suggest that caspase cascades may play an important role in the apoptosis induced by these synthetic cannabinoids. In conclusion, excessive synthetic cannabinoid abuse may present a serious acute health concern due to neuronal damage or deficits in the brain. - Highlights: • Synthetic cannabinoids (classical cannabinoids, non-classical cannabinoids, and aminoalkylindole derivatives) induce cytotoxicity in mouse forebrain cultures. • Synthetic cannabinoid-induced cytotoxicity towards forebrain cultures is mediated by the CB{sub 1} receptor, but not by the CB{sub 2} receptor, and involves caspase-dependent apoptosis. • A high concentration of synthetic cannabinoids may be toxic to neuronal cells that express CB{sub 1} receptors.

  5. Cytotoxicity of synthetic cannabinoids on primary neuronal cells of the forebrain: the involvement of cannabinoid CB1 receptors and apoptotic cell death

    International Nuclear Information System (INIS)

    The abuse of herbal products containing synthetic cannabinoids has become an issue of public concern. The purpose of this paper was to evaluate the acute cytotoxicity of synthetic cannabinoids on mouse brain neuronal cells. Cytotoxicity induced by synthetic cannabinoid (CP-55,940, CP-47,497, CP-47,497-C8, HU-210, JWH-018, JWH-210, AM-2201, and MAM-2201) was examined using forebrain neuronal cultures. These synthetic cannabinoids induced cytotoxicity in the forebrain cultures in a concentration-dependent manner. The cytotoxicity was suppressed by preincubation with the selective CB1 receptor antagonist AM251, but not with the selective CB2 receptor antagonist AM630. Furthermore, annexin-V-positive cells were found among the treated forebrain cells. Synthetic cannabinoid treatment induced the activation of caspase-3, and preincubation with a caspase-3 inhibitor significantly suppressed the cytotoxicity. These synthetic cannabinoids induced apoptosis through a caspase-3-dependent mechanism in the forebrain cultures. Our results indicate that the cytotoxicity of synthetic cannabinoids towards primary neuronal cells is mediated by the CB1 receptor, but not by the CB2 receptor, and further suggest that caspase cascades may play an important role in the apoptosis induced by these synthetic cannabinoids. In conclusion, excessive synthetic cannabinoid abuse may present a serious acute health concern due to neuronal damage or deficits in the brain. - Highlights: • Synthetic cannabinoids (classical cannabinoids, non-classical cannabinoids, and aminoalkylindole derivatives) induce cytotoxicity in mouse forebrain cultures. • Synthetic cannabinoid-induced cytotoxicity towards forebrain cultures is mediated by the CB1 receptor, but not by the CB2 receptor, and involves caspase-dependent apoptosis. • A high concentration of synthetic cannabinoids may be toxic to neuronal cells that express CB1 receptors

  6. In vitro cytotoxicity and genotoxicity studies of gold nanoparticles-mediated photo-thermal therapy versus 5-fluorouracil

    International Nuclear Information System (INIS)

    This study evaluates tumour cell-killing efficacy of metallic gold nanoparticles (AuNPs)-mediated photo-thermal therapy (PTT) in comparison to 5-fluorouracil (5-FU) as a standard chemotherapeutic drug. It also focuses on the possible genetic abnormalities of both drugs in normal blood lymphocytes. Both 5-FU and light-activated spherical AuNPs of 15± nm diameter were used to target MCF-7 breast cancer cell line. Alkaline comet assay, standard karyotyping and multiplex fluorescent in situ hybridization were applied in order to investigate the respective possible genotoxic and mutagenic side effects that might result from the application of each therapeutic modality. Results showed that the LC25 of AuNPs-mediated PTT was achieved at a concentration of 100 µM for 12-h incubation and exposure to light energy of 50 J/cm2, while the same cytotoxic effect was obtained by incubating the MCF-7 cells with the same concentration of the chemotherapeutic drug 5-FU for 24 h. On the other hand, AuNPs showed insignificant genotoxic effect of DNA damage represented by 4.6 % in comparison to 18.58 % exerted by 5-FU. The chromosomal studies resulted in normal karyotypes for cells treated with AuNPs-mediated PTT, while those treated with 5-FU showed several types of numerical as well as structural chromosomal aberrations. In conclusion, compared to 5-FU, light-activated AuNPs-mediated PTT provides considerable efficacy in breast cancer cells killing with no genetic side effects under the proposed experimental conditions

  7. In vitro cytotoxicity and genotoxicity studies of gold nanoparticles-mediated photo-thermal therapy versus 5-fluorouracil

    Energy Technology Data Exchange (ETDEWEB)

    Gomaa, Iman E., E-mail: iman.gomaa@guc.edu.eg; Abdel Gaber, Sara A. [German University in Cairo (GUC), Faculty of Pharmacy and Biotechnology (Egypt); Bhatt, Samarth; Liehr, Thomas [Friedrich Schiller University, Jena University Hospital, Institute of Human Genetics (Germany); Glei, Michael [Friedrich Schiller University, Faculty of Biology and Pharmacy, Institute of Nutrition (Germany); El-Tayeb, Tarek A. [Cairo University, The National Institute for Laser Enhanced Sciences (NILES) (Egypt); Abdel-Kader, Mahmoud H. [German University in Cairo (GUC), Faculty of Pharmacy and Biotechnology (Egypt)

    2015-02-15

    This study evaluates tumour cell-killing efficacy of metallic gold nanoparticles (AuNPs)-mediated photo-thermal therapy (PTT) in comparison to 5-fluorouracil (5-FU) as a standard chemotherapeutic drug. It also focuses on the possible genetic abnormalities of both drugs in normal blood lymphocytes. Both 5-FU and light-activated spherical AuNPs of 15± nm diameter were used to target MCF-7 breast cancer cell line. Alkaline comet assay, standard karyotyping and multiplex fluorescent in situ hybridization were applied in order to investigate the respective possible genotoxic and mutagenic side effects that might result from the application of each therapeutic modality. Results showed that the LC25 of AuNPs-mediated PTT was achieved at a concentration of 100 µM for 12-h incubation and exposure to light energy of 50 J/cm{sup 2}, while the same cytotoxic effect was obtained by incubating the MCF-7 cells with the same concentration of the chemotherapeutic drug 5-FU for 24 h. On the other hand, AuNPs showed insignificant genotoxic effect of DNA damage represented by 4.6 % in comparison to 18.58 % exerted by 5-FU. The chromosomal studies resulted in normal karyotypes for cells treated with AuNPs-mediated PTT, while those treated with 5-FU showed several types of numerical as well as structural chromosomal aberrations. In conclusion, compared to 5-FU, light-activated AuNPs-mediated PTT provides considerable efficacy in breast cancer cells killing with no genetic side effects under the proposed experimental conditions.

  8. Exploiting cannabinoid-induced cytotoxic autophagy to drive melanoma cell death.

    Science.gov (United States)

    Armstrong, Jane L; Hill, David S; McKee, Christopher S; Hernandez-Tiedra, Sonia; Lorente, Mar; Lopez-Valero, Israel; Eleni Anagnostou, Maria; Babatunde, Fiyinfoluwa; Corazzari, Marco; Redfern, Christopher P F; Velasco, Guillermo; Lovat, Penny E

    2015-06-01

    Although the global incidence of cutaneous melanoma is increasing, survival rates for patients with metastatic disease remain Sativex-like (a laboratory preparation comprising equal amounts of THC and cannabidiol (CBD)) to mice bearing BRAF wild-type melanoma xenografts substantially inhibited melanoma viability, proliferation, and tumor growth paralleled by an increase in autophagy and apoptosis compared with standard single-agent temozolomide. Collectively, our findings suggest that THC activates noncanonical autophagy-mediated apoptosis of melanoma cells, suggesting that cytotoxic autophagy induction with Sativex warrants clinical evaluation for metastatic disease. PMID:25674907

  9. Cytotoxic mechanisms of murine lymphokine-activated killer cells: functional and biochemical characterization of homogeneous populations of spleen LAK cells.

    Science.gov (United States)

    Zychlinsky, A; Joag, S; Liu, C C; Young, J D

    1990-04-01

    A highly purified population of murine lymphokine-activated killer (LAK) cells was obtained by selecting plastic-adherent splenocytes after incubation in high doses of recombinant IL-2. The population obtained was shown to be more than 95% positive for the cell marker asialo-GM1, and negative for both Lyt-1 (CD5) and Lyt-2 (CD8). The cells presented typical large granular lymphocyte morphology, and killed NK-susceptible target cells in an exclusively calcium-dependent fashion. A target cell DNA fragmentation activity of LAK cells could be detected even before target cell death. The presence of Hanukkah Factor/granzyme A/serine esterase 1, CTLA-1/granzyme B/serine esterase 2, and pore-forming protein (PFP/perforin) in these LAK cells was demonstrated by Northern blot analysis, suggesting that these markers are not exclusively associated with cytotoxic T lymphocytes. On immunoblots, antibodies specific for a lymphocyte PFP/perforin reacted with a 70-kDa protein of LAK cells. PFP/perforin was localized by immunofluorescence to the cell granules. A 50-kDa protein antigenically related to the macrophage cytokine tumor necrosis factor (TNF) was detected by immunoblotting and localized by immunofluorescence to both the cell granules and the cytosol. No RNA for TNF, however, could be detected using TNF-specific probes, suggesting that LAK cells may contain a cytotoxic factor which is related to, but distinct from, TNF. The work presented here demonstrates that cytotoxic mediators identified in cell lines are also present in primary cell cultures. PMID:1690083

  10. Intrasinusoidal cytotoxic CD8+ T cells in nodular regenerative hyperplasia of the liver.

    Science.gov (United States)

    Ziol, Marianne; Poirel, Helene; Kountchou, Gisele N; Boyer, Olivier; Mohand, Djamila; Mouthon, Luc; Tepper, Maryline; Guillet, Jean-Gerard; Guettier, Catherine; Raphael, Martine; Beaugrand, Michel

    2004-10-01

    Diffuse nodular regenerative hyperplasia (NRH) of the liver is an acquired architectural disturbance that can lead to portal hypertension. Although frequently associated with autoimmune or hematologic malignancies, its exact pathogenesis remains largely unknown. We observed CD8+ cytotoxic T cells in the liver sinusoids of 14 of 44 NRH patients and explored possible relationships between these lymphocytes and vascular damage. The immunophenotype of intrahepatic lymphocytes was determined using immunohistochemical analysis and endothelial injury using the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling method for apoptosis combined with endothelial cell labeling. Controls for the quantitative analysis of liver-infiltrating lymphocytes consisted of patients with chronic hepatitis C or normal liver (n = 13 and n = 6, respectively). Liver specimens from the 14 patients dislayed intrasinusoidal infiltrate composed of CD3+ and CD8+ lymphocytes, located near atrophic liver cell plates. Significantly more granzyme B+ and CD57+ lymphocytes were observed in NRH than chronic hepatitis C samples with quantitatively similar CD8+ infiltrates. Double-labeling revealed apoptotic endothelial sinusoidal cells in CD8+ T-cell-infiltrated areas in all NRH samples but never in chronic hepatitis C or normal livers. T-cell receptor rearrangement or immunoscope analysis suggested liver-specific polyclonal or oligoclonal T-cell expansions. Clinical and biological characteristics of the 14 patients were similar to those observed in the 30 patients with NRH devoid of lymphocytic infiltration. We report here that CD8+ cytotoxic T cells infiltrated the liver sinusoids of a high percentage (32%) of NRH patients and suggest that some NRH cases might result from chronic, cytotoxic CD8+ T-lymphocyte targeting of sinusoidal endothelial cells. PMID:15492992

  11. Selective cytotoxic effect of 1-O-undecylglycerol in human melanoma cells

    Directory of Open Access Journals (Sweden)

    Marian Hernández-Colina

    2016-04-01

    Full Text Available Context: 1-O-alkylglycerols are ether-linked glycerols derived from shark liver oil and found in small amounts in human milk. Previous studies showed antineoplastic activity for this family of compounds, structurally related to alkylphospholipids, but the activity of linear chain synthetic alkylglycerols in cancer cell lines is less documented. Melanoma is a high incidence cancer, highly resistant to potential treatments. Finding new anti-cancer compounds to improve melanoma prognosis is a relevant research issue. Aims: To study the cytotoxic effect of 1-O-undecylglycerol in primary cultured normal fibroblasts and A375 human melanoma cell line. Methods: Cells were treated with different concentrations of 1-O-undecylglycerol and viability assessed by MTT assay. Morphological changes were visualized by DAPI and acridine orange-ethidium bromide staining. Mitochondrial membrane potential was evaluated, and gene expression of P53 and BcL-2 was semi-quantified. Results: 1-O-undecylglycerol decreased viability of A375 cells and exerted very low cytotoxicity on primary cultured normal fibroblasts. Necrosis appeared in A375 cells but not in fibroblasts, and no apoptotic changes were visualized in DAPI staining experiments. After 24 h fibroblasts and melanoma cells developed mitochondrial potential changes similar to valinomycin. The gene expression of P53 and BcL-2 decreased in treated cells. Conclusions: 1-O-undecylglycerol exhibited selective cytotoxic activity in A375 melanoma cells when compared with primary cultured fibroblast. Its toxicity is mediated by necrosis that may be related with mitochondrial events and decrease in P53 and BcL-2 expression. The results suggest that UDG could be a useful strategy to combine with other chemotherapeutic agents in melanoma treatment.

  12. Preferentially Cytotoxic Constituents of Andrographis paniculata and their Preferential Cytotoxicity against Human Pancreatic Cancer Cell Lines.

    Science.gov (United States)

    Lee, Sullim; Morita, Hiroyuki; Tezuka, Yasuhiro

    2015-07-01

    In the course of our search for anticancer agents based on a novel anti-austerity strategy, we found that the 70% EtOH extract of the crude drug Andrographis Herba (aerial parts of Andrographis paniculata), used in Japanese Kampo medicines, killed PANC-1 human pancreatic cancer cells preferentially in nutrient-deprived medium (NDM). Phytochemical investigation of the 70% EtOH extract led to the isolation of 21 known compounds consisting of six labdane-type diterpenes (11, 15, 17-19, 21), six flavones (5, 7, 10, 12, 14, 20), three flavanones (2, 6, 16), two sterols (3, 8), a fatty acid (1), a phthalate (4), a triterpene (9), and a monoterpene (13). Among them, 14-deoxy-11,12-didehydroandrographolide (17) displayed the most potent preferential cytotoxicity against PANC-1 and PSN-1 cells with PC50 values of 10.0 μM and 9.27 μM, respectively. Microscopical observation, double staining with ethidium bromide (EB) and acridine orange (AO), and flow cytometry with propidium iodide/annexin V double staining indicated that 14-deoxy-11,12-didehydroandrographolide (17) triggered apoptosis-like cell death in NDM with an amino acids and/or serum-sensitive mode. PMID:26410998

  13. Cytotoxicity of yellow sand in lung epithelial cells

    Indian Academy of Sciences (India)

    Y H Kim; K S Kim; N J Kwak; K H Lee; S A Kweon; Y Lim

    2003-02-01

    The present study was carried out to observe the cytotoxicity of yellow sand in comparison with silica and titanium dioxide in a rat alveolar type II cell line (RLE-6TN). Yellow sand (China Loess) was obtained from the loess layer in the Gunsu Province of China. The mean particle diameter of yellow sand was about 0.003 ± 0.001 mm. Major elements of yellow sand were Si(27.7 ± 0.6%), Al(6.01 ± 0.17%), and Ca(5.83 ± 0.23%) in that order. Silica and yellow sand significantly decreased cell viability and increased [Ca2+]i. All three particles increased the generation of H2O2. TiO2 did not change Fenton activity, while silica induced a slight increase of Fenton activity. In contrast, yellow sand induced a significant increase of Fenton activity. Silica, yellow sand and TiO2 induced significant nitrite formations in RLE-6TN cells. Silica showed the highest increase in nitrite formation, while yellow sand induced the least formation of nitrite. Silica and yellow sand increased the release of TNF-. Based on these results, we suggest that yellow sand can induce cytotoxicity in RLE-6TN cells and reactive oxygen species, Fenton activity and reactive nitrogen species might be involved in this toxicity.

  14. Methotrexate-conjugated quantum dots: synthesis, characterisation and cytotoxicity in drug resistant cancer cells.

    Science.gov (United States)

    Johari-Ahar, Mohammad; Barar, Jaleh; Alizadeh, Ali Mohammad; Davaran, Soodabeh; Omidi, Yadollah; Rashidi, Mohammad-Reza

    2016-01-01

    Methotrexate (MTX), a folic acid derivative, is a potent anticancer used for treatment of different malignancies, but possible initiation of drug resistance to MTX by cancer cells has limited its applications. Nanoconjugates (NCs) of MTX to quantum dots (QDs) may favour the cellular uptake via folate receptors (FRs)-mediated endocytosis that circumvents the efflux functions of cancer cells. We synthesised MTX-conjugated l-cysteine capped CdSe QDs (MTX-QD nanoconjugates) and evaluated their internalisation and cytotoxicity in the KB cells with/without resistancy to MTX. The NCs were fully characterised by high resolution transmission electron microscopy (HR-TEM), atomic force microscopy (AFM), dynamic light scattering (DLS) and optical spectroscopy. Upon conjugation with MTX, the photoluminescence (PL) properties of QDs altered, while an obvious quenching in PL of QDs was observed after physical mixing. The MTX-QD nanoconjugates efficiently internalised into the cancer cells, and induced markedly high cytotoxicity (IC50, 12.0 µg/mL) in the MTX-resistant KB cells as compared to the free MTX molecules (IC50,105.0 µg/mL), whereas, these values were respectively about 7.0 and 0.6 µg/mL in the MTX-sensitive KB cells. Based on these findings, the MTX-QD nanoconjugates are proposed for the targeted therapy of MTX-resistant cancers, which may provide an improved outcome in the relapsed FR-overexpressing cancers. PMID:26176269

  15. Trichloroethylene-mediated cytotoxicity in human epidermal keratinocytes is mediated by the rapid accumulation of intracellular calcium: Interception by naringenin.

    Science.gov (United States)

    Ali, F; Khan, A Q; Khan, R; Sultana, S

    2016-02-01

    Industrial solvents pose a significant threat to the humankind. The mechanisms of their toxicity still remain in debate. Trichloroethylene (TCE) is a widespread industrial solvent responsible for severe liver dysfunction, cutaneous toxicity in occupationally exposed humans. We utilized an in vitro system of human epidermal keratinocyte (HaCaT) cells in this study to avoid complex cell and extracellular interactions. We report the cytotoxicity of organic solvent TCE in HaCaT and its reversal by a natural flavanone, naringenin (Nar). The cytotoxicity was attributed to the rapid intracellular free calcium (Ca(2+)) release, which might lead to the elevation of protein kinase C along with robust free radical generation, instability due to energy depletion, and sensitization of intracellular stress signal transducer nuclear factor κB. These effects were actually seen to induce significant amount of genomic DNA fragmentation. Furthermore, all these effects of TCE were effectively reversed by the treatment of Nar, a natural flavanone. Our studies identify intracellular Ca as a unique target used by organic solvents in the cytotoxicity and highlight the Ca(2+) ion stabilizer properties of Nar. PMID:25855085

  16. Newly synthesized hypoxia-mediated drugs as radiosensitizers and cytotoxic agents

    International Nuclear Information System (INIS)

    Chinese hamster cells in culture were used to compare the radiosensitizing efficiency and cytotoxicity of misonidazole with several 2, 4 and 5 substituted nitroimidazoles. The two substituted compounds (SR 2508 and SR 2555) are similar to misonidazole in radiosensitizing effectivenss, but are significantly less toxic to hypoxic cells. This reduced cytotoxicity may result from either slower drug penetration or slower removal of non-protein sulfhydryl compounds (NPSH). The compound MJL-1-191-VII* (a 4-nitroimidazole) is a much more effective radiosensitizer than would be predicted from its electron affinity. It appears to sensitize by two mechanisms, the first resulting from its electron affinity and the second a consequence of its rapid removal of endogeneous cellular NPSH; which are naturally occurring radioprotective substances

  17. Newly synthesized hypoxia-mediated drugs as radiosensitizers and cytotoxic agents

    International Nuclear Information System (INIS)

    Chinese hamster cells in culture were used to compare the radiosensitizing efficiency and cytotoxicity of misonidazole with several 2, 4 and 5 substituted nitroimidazoles. The two subsituted compounds (SR 2508 and SR 2555) are similar to misonidazole in radiosensitizing effectiveness, but are significantly less toxic to hypoxic cells. This reduced cytotoxicity may result from either slower drug penetration or slower removal of non-protein sulfhydryl compounds (NPSH). The compound MJL-1-191-VII* (a 4-nitroimidazole) is a much more effective radiosensitizer than would be predicted from its electron affinity. It appears to sensitize by two mechanisms, the first resulting from its electron affinity and the second a consequence of its rapid removal of endogeneous cellular NPSH; which are naturally occurring radioprotective substances

  18. Ultrastructural studies of time-course and cellular specificity of interleukin-1 mediated islet cytotoxicity

    DEFF Research Database (Denmark)

    Mandrup-Poulsen, T; Egeberg, J; Nerup, J; Bendtzen, K; Dinarello, C A; Nielsen, Jens Høiriis

    1987-01-01

    Previous electron-microscopic studies of isolated islets of Langerhans exposed to the monokine interleukin-1 for 7 days have indicated that interleukin-1 is cytotoxic to all islet cells. To study the time-course and possible cellular specificity of interleukin-1 cytotoxicity to islets exposed to...... interleukin-1 for short time periods, isolated rat or human islets were incubated with or without 25 U/ml highly purified human interleukin-1 for 24 h. Samples of rat islets were taken after 5 min, 30 min, 1, 2, 4, 6, 8, 10, 12, 16, 20 and 24 h and samples of human islets after 5 min, 30 min and 24 h of...... incubation and examined by electron microscopy in a blinded fashion. Already after 30 min, accumulation of opaque intracytoplasmic bodies without apparent surrounding membranes, and autophagic vacuoles were seen in about 20% of the beta cells examined in rat islets exposed to interleukin-1. After 16 h of...

  19. Memory lineage relationships in HTLV-1-specific CD8+ cytotoxic T cells

    Science.gov (United States)

    Johnson-Nauroth, Julie M.; Graber, Jerome; Yao, Karen; Jacobson, Steve; Calabresi, Peter A.

    2016-01-01

    Cytotoxic memory T cells play a critical role in combating viral infections; however, in some diseases they may contribute to tissue damage. In HAM/TSP, HTLV-1 Tax 11–19+ cells proliferate spontaneously in vitro and can be tracked using the Tax 11–19 MHC Class I tetramer. Immediately ex vivo, these cells were a mix of CD45RA−/CCR7− TEM and CD45RA+/CCR7− TDiff memory CTL. The subsequent proliferating Tax 11–19 tetramer+ population expressed low levels of IL-7Rα, failed to respond to IL-7 and IL-15, and did not develop a TCM phenotype. Thus, chronic exposure to viral antigen may result in a sustained pool of TEM cells that home to the CNS and mediate the spinal cord pathology seen in this disease. PMID:16740321

  20. Deoxynivalenol induces cytotoxicity and genotoxicity in animal primary cell culture.

    Science.gov (United States)

    Singh, Shweta; Banerjee, Subham; Chattopadhyay, Pronobesh; Borthakur, Sashin Kumar; Veer, Vijay

    2015-03-01

    Deoxynivalenol (DON), a mycotoxin produced by Fusarium graminearum, is widely found as a contaminant of food. DON is responsible for a wide range of toxic activities, including gastro-intestinal, lymphoid, bone-marrow and cardiotoxicity. But, the complete explorations of toxicity in terms of hepatotoxicity, nephrotoxicity, cytotoxicity and genotoxicity as well have not been documented well. Again, the mechanisms through which DON damages the DNA and promotes cellular toxicity are not well established. Considering the above fact, this research article is focused on the effects of DON-induced toxicities on experimental animal model as well as its effects on cellular level via various toxicological investigations. DON treatment showed cytotoxicity and DNA damage. Further, flow cytometric analysis of hepatocytes showed cellular apoptosis, suggesting that DON-induced hepatotoxicity is, may be partly, mediated by apoptosis. Moreover, significant differences were found in each haematology and clinical chemistry value, either (p > 0.05). No abnormality of any organ was found during histopathological examination. Hence, it can be concluded that DON induces oxidative DNA damage and increases the formation of centromere positive micronuclei due to aneugenic activity. PMID:25578892

  1. Cytotoxic effects of catechols to glial and neuronal cells

    Directory of Open Access Journals (Sweden)

    Ramon Santos El-Bachá

    2015-04-01

    Full Text Available Catechols are compounds that autoxidises under physiological conditions leading to the formation of reactive oxygen species (ROS, semiquinones, and quinones. These molecules can be formed in organisms because of the metabolism of exogenous aromatic substances, such as benzene. However, there are several important endogenous catechols, which have physiological functions, such as catecholamines. Furthermore, several pharmacological agents are catechols, such as apomorphine, or can be metabolised to generate these compounds. In this presentation we will show that apomorphine can unspecifically bind to proteins during its autoxidation, a phenomenon that is inhibited by thiols. Brain endothelial cells and glial cells express xenobiotic-metabolising enzymes as components of the metabolic blood-brain barrier in an attempt to protect the central nervous system against drugs. Since UDP-glucuronosyltransferases (EC 2.4.1.17 are among these enzymes, we investigated the ability of brain microsomes to conjugate catechols with glucuronate. Despite the fact that 1-naphtol could be glucuronidated in the presence of brain cortex microsomes, the same was not observed for most of catechols that were tested. Therefore, this is not the main mechanism used to protect the brain against them. Indeed, catechols may inhibit other xenobiotic-metabolising enzymes. We showed that apomorphine inhibited the cytochrome P450-dependent dealkylation activity. The production of ROS and reactive quinones, as well as their effects on protein functions, seems to be involved in the cytotoxicity of catechols. Glial cells are more resistant than neuronal cells. Apomorphine was more toxic to rat neurons than to rat C6 glioma cells. 1,2-Dihydroxybenzene (catechol killed human GL-15 cells with an EC50 of 230 uM after 72 h, a effect that was significantly inhibited by superoxide dismutase (EC 1.15.1.1. Another mechanism that we found to be involved in catechol cytotoxicity is the inhibition

  2. Cytotoxic and inflammatory responses of TiO2 nanoparticles on human peripheral blood mononuclear cells.

    Science.gov (United States)

    Kongseng, Supunsa; Yoovathaworn, Krongtong; Wongprasert, Kanokpan; Chunhabundit, Rodjana; Sukwong, Patinya; Pissuwan, Dakrong

    2016-10-01

    Titanium dioxide nanoparticles (TiO2 -NPs) have been widely used in many applications. Owing to their nanoscale size, interactions between cells and NPs have been expansively investigated. With the health concerns raised regarding the adverse effects of these interactions, closer examination of whether TiO2 -NPs can induce toxicity towards human cells is greatly needed. Therefore, in this study, we investigated the cytotoxicity of TiO2 -NPs towards human blood cells (peripheral blood mononuclear cells [PBMCs]) in serum-free medium, for which there is little information regarding the cytotoxic effects of TiO2 -NPs. Our results provide evidence that PBMCs treated with TiO2 -NPs (at concentrations ≥25 μg ml(-1) ) for 24 h significantly reduced cell viability and significantly increased production of toxic mediators such as reactive oxygen species and inflammatory response cytokines such as interleukin-6 and tumor necrosis factor-α (P < 0.05). Cell apoptosis induction also occurred at these concentrations. Significant expressions of cyclooxygenase-2 and interleukin-1β were also observed in PBMCs treated with TiO2 -NPs at concentrations ≥125 μg ml(-1) . Our data presented here clearly indicate that the concentration of TiO2 -NPs (at size ~26.4 ± 1.2 nm) applied to human blood cells has a strong impact on cytotoxic induction. Copyright © 2016 John Wiley & Sons, Ltd. PMID:27225715

  3. Real-time impedimetric monitoring of Poly(ethylenimine)s-mediated cytotoxicity during gene transfection

    DEFF Research Database (Denmark)

    Caviglia, Claudia; Carminati, Marco; Heiskanen, Arto;

    , distant counter electrode (CE)), and the interdigitated configuration (WEa comb versus WEb comb) ) have been used and compared on the same cell population, providing optimal detection conditions. The experiments have been performed by initially seeding about 103 cells into each chamber, continuously...... perfused with fresh culture medium. The platform was incubated in a humidified atmosphere. After 24 hours, different concentrations of PEIs have been introduced in the culture medium and the incubation continued for other 24 hours. Cell adhesion, growth and PEI-cytotoxicity have been detected in real...

  4. Ochratoxin A: induction of (oxidative) DNA damage, cytotoxicity and apoptosis in mammalian cell lines and primary cells

    International Nuclear Information System (INIS)

    Ochratoxin A (OTA) is a nephrotoxic/-carcinogenic mycotoxin, produced by several Aspergillus- and Penicillium-strains. Humans are exposed to OTA via food contamination, a causal relationship of OTA to human endemic Balkan nephropathy is still under debate. Since DNA-adducts of OTA or its metabolites could not be identified unambiguously, its carcinogenic effectiveness might be related to secondary effects, such as oxidative cell damage or cell proliferation. In this study, OTA mediated induction of (oxidative) DNA damage, cytotoxicity (necrosis, growth inhibition, apoptosis) and modulation of glutathione were investigated in cell lines (V79, CV-1) and primary rat kidney cells. After 24 h incubation, viability of V79 cells was strongly decreased by OTA concentrations >2.5 μmol/L, whereas CV-1 cells were clearly less sensitive. Strong growth inhibition occurred in both cell lines (IC50 ∼2 μmol/L). Apoptosis, detected with an immunochemical test and with flow cytometry, was induced by >1 μmol/L OTA. Oxidative DNA damage, detected by comet assay after additional treatment with repair enzymes, was induced in all cell systems already at five-fold lower concentrations. Glutathione in CV-1 cells was depleted after 1 h incubation (>100 μmol/L). In contrast, an increase was measured after 24 h incubation (>0.5 μmol/L). In conclusion, OTA induces oxidative DNA damage at low, not yet cytotoxic concentrations. Oxidative DNA damage might initiate cell transformation eventually in connection with proliferative response following cytotoxic cell death. Both events might represent pivotal factors in the chain of cellular events leading into nephro-carcinogenicity of OTA

  5. A new class of pluripotent stem cell cytotoxic small molecules.

    Directory of Open Access Journals (Sweden)

    Mark Richards

    Full Text Available A major concern in Pluripotent Stem Cell (PSC-derived cell replacement therapy is the risk of teratoma formation from contaminating undifferentiated cells. Removal of undifferentiated cells from differentiated cultures is an essential step before PSC-based cell therapies can be safely deployed in a clinical setting. We report a group of novel small molecules that are cytotoxic to PSCs. Our data indicates that these molecules are specific and potent in their activity allowing rapid eradication of undifferentiated cells. Experiments utilizing mixed PSC and primary human neuronal and cardiomyocyte cultures demonstrate that up to a 6-fold enrichment for specialized cells can be obtained without adversely affecting cell viability and function. Several structural variants were synthesized to identify key functional groups and to improve specificity and efficacy. Comparative microarray analysis and ensuing RNA knockdown studies revealed involvement of the PERK/ATF4/DDIT3 ER stress pathway. Surprisingly, cell death following ER stress induction was associated with a concomitant decrease in endogenous ROS levels in PSCs. Undifferentiated cells treated with these molecules preceding transplantation fail to form teratomas in SCID mice. Furthermore, these molecules remain non-toxic and non-teratogenic to zebrafish embryos suggesting that they may be safely used in vivo.

  6. Salinomycin potentiates the cytotoxic effects of TRAIL on glioblastoma cell lines.

    Directory of Open Access Journals (Sweden)

    Alessia Calzolari

    Full Text Available Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL has been reported to exhibit therapeutic activity in cancer. However, many tumors remain resistant to treatment with TRAIL. Therefore, small molecules that potentiate the cytotoxic effects of TRAIL could be used for combinatorial therapy. Here we found that the ionophore antibiotic salinomycin acts in synergism with TRAIL, enhancing TRAIL-induced apoptosis in glioma cells. Treatment with low doses of salinomycin in combination with TRAIL augmented the activation of caspase-3 and increased TRAIL-R2 cell surface expression. TRAIL-R2 upmodulation was required for mediating the stimulatory effect of salinomycin on TRAIL-mediated apoptosis, since it was abrogated by siRNA-mediated TRAIL-R2 knockdown. Salinomycin in synergism with TRAIL exerts a marked anti-tumor effect in nude mice xenografted with human glioblastoma cells. Our results suggest that the combination of TRAIL and salinomycin may be a useful tool to overcome TRAIL resistance in glioma cells and may represent a potential drug for treatment of these tumors. Importantly, salinomycin+TRAIL were able to induce cell death of well-defined glioblastoma stem-like lines.

  7. Sorafenib enhances proteasome inhibitor-mediated cytotoxicity via inhibition of unfolded protein response and keratin phosphorylation

    International Nuclear Information System (INIS)

    Hepatocellular carcinoma (HCC) is highly resistant to conventional systemic therapies and prognosis for advanced HCC patients remains poor. Recent studies of the molecular mechanisms responsible for tumor initiation and progression have identified several potential molecular targets in HCC. Sorafenib is a multi-kinase inhibitor shown to have survival benefits in advanced HCC. It acts by inhibiting the serine/threonine kinases and the receptor type tyrosine kinases. In preclinical experiments sorafenib had anti-proliferative activity in hepatoma cells and it reduced tumor angiogenesis and increased apoptosis. Here, we demonstrate for the first time that the cytotoxic mechanisms of sorafenib include its inhibitory effects on protein ubiquitination, unfolded protein response (UPR) and keratin phosphorylation in response to endoplasmic reticulum (ER) stress. Moreover, we show that combined treatment with sorafenib and proteasome inhibitors (PIs) synergistically induced a marked increase in cell death in hepatoma- and hepatocyte-derived cells. These observations may open the way to potentially interesting treatment combinations that may augment the effect of sorafenib, possibly including drugs that promote ER stress. Because sorafenib blocked the cellular defense mechanisms against hepatotoxic injury not only in hepatoma cells but also in hepatocyte-derived cells, we must be careful to avoid severe liver injury. -- Graphical abstract: Display Omitted -- Highlights: •We examined the cytotoxic mechanisms of sorafenib in hepatoma cells. •Sorafenib induces cell death via apoptotic and necrotic fashion. •Sorafenib inhibits protein ubiquitination and unfolded protein response. •Autophagy induced by sorafenib may affect its cytotoxicity. •Sorafenib inhibits keratin phosphorylation and cytoplasmic inclusion formation

  8. Sorafenib enhances proteasome inhibitor-mediated cytotoxicity via inhibition of unfolded protein response and keratin phosphorylation

    Energy Technology Data Exchange (ETDEWEB)

    Honma, Yuichi; Harada, Masaru, E-mail: msrharada@med.uoeh-u.ac.jp

    2013-08-15

    Hepatocellular carcinoma (HCC) is highly resistant to conventional systemic therapies and prognosis for advanced HCC patients remains poor. Recent studies of the molecular mechanisms responsible for tumor initiation and progression have identified several potential molecular targets in HCC. Sorafenib is a multi-kinase inhibitor shown to have survival benefits in advanced HCC. It acts by inhibiting the serine/threonine kinases and the receptor type tyrosine kinases. In preclinical experiments sorafenib had anti-proliferative activity in hepatoma cells and it reduced tumor angiogenesis and increased apoptosis. Here, we demonstrate for the first time that the cytotoxic mechanisms of sorafenib include its inhibitory effects on protein ubiquitination, unfolded protein response (UPR) and keratin phosphorylation in response to endoplasmic reticulum (ER) stress. Moreover, we show that combined treatment with sorafenib and proteasome inhibitors (PIs) synergistically induced a marked increase in cell death in hepatoma- and hepatocyte-derived cells. These observations may open the way to potentially interesting treatment combinations that may augment the effect of sorafenib, possibly including drugs that promote ER stress. Because sorafenib blocked the cellular defense mechanisms against hepatotoxic injury not only in hepatoma cells but also in hepatocyte-derived cells, we must be careful to avoid severe liver injury. -- Graphical abstract: Display Omitted -- Highlights: •We examined the cytotoxic mechanisms of sorafenib in hepatoma cells. •Sorafenib induces cell death via apoptotic and necrotic fashion. •Sorafenib inhibits protein ubiquitination and unfolded protein response. •Autophagy induced by sorafenib may affect its cytotoxicity. •Sorafenib inhibits keratin phosphorylation and cytoplasmic inclusion formation.

  9. Dual Requirement of Cytokine and Activation Receptor Triggering for Cytotoxic Control of Murine Cytomegalovirus by NK Cells

    Science.gov (United States)

    Pak-Wittel, Melissa A.; Yang, Liping; Schreiber, Robert D.; Yokoyama, Wayne M.

    2015-01-01

    Natural killer (NK) cells play a critical role in controlling murine cytomegalovirus (MCMV) and can mediate both cytokine production and direct cytotoxicity. The NK cell activation receptor, Ly49H, is responsible for genetic resistance to MCMV in C57BL/6 mice. Recognition of the viral m157 protein by Ly49H is sufficient for effective control of MCMV infection. Additionally, during the host response to infection, distinct immune and non-immune cells elaborate a variety of pleiotropic cytokines which have the potential to impact viral pathogenesis, NK cells, and other immune functions, both directly and indirectly. While the effects of various immune deficiencies have been examined for general antiviral phenotypes, their direct effects on Ly49H-dependent MCMV control are poorly understood. To specifically interrogate Ly49H-dependent functions, herein we employed an in vivo viral competition approach to show Ly49H-dependent MCMV control is specifically mediated through cytotoxicity but not IFNγ production. Whereas m157 induced Ly49H-dependent degranulation, efficient cytotoxicity also required either IL-12 or type I interferon (IFN-I) which acted directly on NK cells to produce granzyme B. These studies demonstrate that both of these distinct NK cell-intrinsic mechanisms are integrated for optimal viral control by NK cells. PMID:26720279

  10. A new cell line for high throughput HIV-specific antibody-dependent cellular cytotoxicity (ADCC) and cell-to-cell virus transmission studies

    Science.gov (United States)

    Orlandi, Chiara; Flinko, Robin; Lewis, George K.

    2016-01-01

    Several lines of evidence indicate that antibody-dependent cellular cytotoxicity (Wren et al., 2013) is important in the pathogenesis of HIV-1 infection. Namely, ADCC is induced during natural HIV-1 infection or in HIV-1 vaccine studies, the latter demonstrated by the RV144 vaccine trial. To expedite the assessment of ADCC in studies of HIV, we have developed a high throughput assay. We have optimized the rapid fluorometric antibody-mediated cytotoxicity assay (RFADCC) by transfecting the EGFP-CEM-NKr cell line to constitutively express SNAP-tagged CCR5. This cell line can then serve as a source of HIV-specific targets when coated with monomeric gp120, spinoculated with inactivated intact virions, infected by cell-free viral diffusion or infected by cell-to-cell transmission of virus. The optimized strategy has two significant advantages over the original RFADCC method: First, the preparation of detectable target cells is less labor intensive and faster as it does not rely on multiple staining and washing steps for target cells. Second, because the target cell markers GFP and SNAP are constitutively expressed, the assay provides highly reproducible data. These strengths make the optimized RFADCC assay suitable not only for studies of HIV-1 specific cytotoxicity but also for studies of cell–cell transmission of virus. In conclusion, this assay provides a new generation T cell line that can expedite large clinical studies as well as research studies in humans or non-human primates. PMID:26969387

  11. Cytochrome P450 peroxidase/peroxygenase mediated xenobiotic metabolic activation and cytotoxicity in isolated hepatocytes.

    Science.gov (United States)

    Anari, M R; Khan, S; Liu, Z C; O'Brien, P J

    1995-12-01

    Cytochrome P450 (P450) can utilize organic hydroperoxides and peracids to support hydroxylation and dealkylation of various P450 substrates. However, the biological significance of this P450 peroxygenase/peroxidase activity in the bioactivation of xenobiotics in intact cells has not been demonstrated. We have shown that tert-butyl hydroperoxide (tBHP) markedly enhances 3-20-fold the cytotoxicity of various aromatic hydrocarbons and their phenolic metabolites. The tBHP-enhanced hepatocyte cytotoxicity of 4-nitroanisole (4-NA) and 4-hydroxyanisole (4-HA) was also accompanied by an increase in the hepatocyte O-demethylation of 4-NA and 4-HA up to 7.5- and 21-fold, respectively. Hepatocyte GSH conjugation by 4-HA was also markedly increased by tBHP. An LC/MS analysis of the GSH conjugates identified hydroquinone-GSH and 4-methoxy-catechol:GSH conjugates as the predominant adducts. Pretreatment of hepatocytes with P450 inhibitors, e.g., phenylimidazole, prevented tBHP-enhanced 4-HA metabolism, GSH depletion, and cytotoxicity. In conclusion, hydroperoxides can therefore be used by intact cells to support the bioactivation of xenobiotics through the P450 peroxidase/peroxygenase system. PMID:8605292

  12. Non-major histocompatibility complex-restricted cytotoxic activity of blood mononuclear cells stimulated with secreted mycobacterial proteins and other mycobacterial antigens

    DEFF Research Database (Denmark)

    Ravn, P; Pedersen, B K

    1994-01-01

    Several observations indicate that non-major histocompatibility complex (MHC)-restricted cytotoxicity, mediated for example by natural killer cells and lymphokine-activated killer cells, may serve as an important antimicrobial defense mechanism. The purpose of the present study was to investigate...

  13. Direct and indirect air particle cytotoxicity in human alveolar epithelial cells.

    Science.gov (United States)

    Orona, N S; Astort, F; Maglione, G A; Saldiva, P H N; Yakisich, J S; Tasat, D R

    2014-08-01

    Air particulate matter has been associated with adverse impact on the respiratory system leading to cytotoxic and proinflammatory effects. The biological mechanisms behind these associations may be initiated by inhaled small size particles, particle components (soluble fraction) and/or mediators released by particle-exposed cells (conditioned media). The effect of Urban Air Particles from Buenos Aires (UAP-BA) and Residual Oil Fly Ash (ROFA) a surrogate of ambient air pollution, their Soluble Fractions (SF) and Conditioned Media (CM) on A549 lung epithelial cells was examined. After 24 h exposure to TP (10 and 100 μg/ml), SF or CM, several biological parameters were assayed on cultured A549 cells. We tested cell viability by MTT, superoxide anion (O₂(-)) generation by NBT and proinflammatory cytokine (TNFα, IL-6 and IL-8) production by ELISA. UAP-BA particles or its SF (direct effect) did not modify cell viability and generation of O₂(-) for any of the doses tested. On the contrary, UAP-BA CM (indirect effect) reduced cell viability and increased both generation of O₂(-) and IL-8 production. Exposure to ROFA particles, SF or ROFA CM reduced proliferation and O₂(-) but, stimulated IL-8. It is worth to note that UAP-BA and ROFA depicted distinct effects on particle-exposed A549 cells implicating morphochemical dependence. These in vitro findings support the hypothesis that particle-induced lung inflammation and disease may involve lung-derived mediators. PMID:24590061

  14. Selective cytotoxicity of marine algae extracts to several human leukemic cell lines

    OpenAIRE

    Harada, Hideki; Kamei, Yuto

    1997-01-01

    Extracts from 8 species of marine algae which showed selective cytotoxicity in our previous screening program, were further examined for cytotoxic spectra to five human leukemic cell lines. The extract from a red alga, Amphiroa zonata exhibited strong cytotoxicity to all human leukemic cell lines tested and murine leukemic cells L1210 at the final concentrations from 15 to 375 µg ml−1. Then the cytotoxicity was not found in normal human fibroblast HDF and murine normal cells NIH-3T3. The acti...

  15. Methyl 6-Amino-6-deoxy-d-pyranoside-Conjugated Platinum(II) Complexes for Glucose Transporter (GLUT)-Mediated Tumor Targeting: Synthesis, Cytotoxicity, and Cellular Uptake Mechanism.

    Science.gov (United States)

    Li, Taoli; Gao, Xiangqian; Yang, Liu; Shi, Yunli; Gao, Qingzhi

    2016-05-19

    Methyl 6-aminodeoxy-d-pyranoside-derived platinum(II) glycoconjugates were designed and synthesized based on the clinical drug oxaliplatin for glucose transporter (GLUT)-mediated tumor targeting. In addition to a substantial improvement in water solubility, the conjugates exhibited cytotoxicity similar to or higher than that of oxaliplatin in six different human cancer cell lines. GLUT-mediated transport of the complexes was investigated with a cell-based fluorescence competition assay and GLUT-inhibitor-mediated cytotoxicity analysis in a GLUT-overexpressing human colorectal adenocarcinoma (HT29) cell line. The antitumor effect of the aminodeoxypyranoside-conjugated platinum(II) complexes was found to depend significantly on the GLUT inhibitor, and the cellular uptake of the molecules was regulated by GLUT-mediated transport. The results from this study demonstrate the potential advantages of aminodeoxypyranosides as sugar motifs for glycoconjugation for Warburg-effect-targeted drug design. These fundamental results also support the potential of aminodeoxypyranoside-conjugated platinum(II) complexes as lead compounds for further preclinical evaluation. PMID:27135196

  16. Identification of Cytotoxic T Lymphocyte Epitopes on Swine Viruses: Multi-Epitope Design for Universal T Cell Vaccine

    OpenAIRE

    Liao, Yu-Chieh; Lin, Hsin-Hung; Lin, Chieh-Hua; Chung, Wen-Bin

    2013-01-01

    Classical swine fever (CSF), foot-and-mouth disease (FMD) and porcine reproductive and respiratory syndrome (PRRS) are the primary diseases affecting the pig industry globally. Vaccine induced CD8+ T cell-mediated immune response might be long-lived and cross-serotype and thus deserve further attention. Although large panels of synthetic overlapping peptides spanning the entire length of the polyproteins of a virus facilitate the detection of cytotoxic T lymphocyte (CTL) epitopes, it is an ex...

  17. A Potential Daidzein Derivative Enhances Cytotoxicity of Epirubicin on Human Colon Adenocarcinoma Caco-2 Cells

    Directory of Open Access Journals (Sweden)

    Yu-Li Lo

    2012-12-01

    Full Text Available In this study, we evaluated the effects of 8-hydroxydaidzein (8HD, an isoflavone isolated from fermented soy germ koji, and epirubicin (Epi, an antineoplastic agent, on the production of reactive oxygen species (ROS. We subsequently correlated the ROS levels to the anticancer mechanisms of Epi and 8HD in human colon adenocarcinoma Caco-2 cells. 8HD enhanced cytotoxicity of Epi and generated a synergistic effect. Epi and/or 8HD treatments increased the hydrogen peroxide and superoxide levels. Combined treatment markedly decreased mRNA expression levels of multidrug resistance protein 1 (MDR1, MDR-associated protein (MRP 1, and MRP2. 8HD significantly intensified Epi intracellular accumulation in Caco-2 cells. 8HD and/or Epi-induced apoptosis, as indicated by the reduced mitochondrial membrane potential and increased sub-G1 phase in cell cycle. Moreover, 8HD and Epi significantly enhanced the mRNA expressions of Bax, p53, caspases-3, -8, and -9. To our best knowledge, this study verifies for the first time that 8HD effectively circumvents MDR in Caco-2 cells through the ROS-dependent inhibition of efflux transporters and p53-mediated activation of both death receptor and mitochondrial pathways of apoptosis. Our findings of 8HD shed light on the future search for potential biotransformed isoflavones to intensify the cytotoxicity of anticancer drugs through simultaneous reversal of pump and nonpump resistance.

  18. Notch-Mediated Cell Adhesion

    OpenAIRE

    Akihiko Murata; Shin-Ichi Hayashi

    2016-01-01

    Notch family members are generally recognized as signaling molecules that control various cellular responses in metazoan organisms. Early fly studies and our mammalian studies demonstrated that Notch family members are also cell adhesion molecules; however, information on the physiological roles of this function and its origin is limited. In this review, we discuss the potential present and ancestral roles of Notch-mediated cell adhesion in order to explore its origin and the initial roles of...

  19. Evaluation of cytotoxicity, morphological alterations and oxidative stress in Chinook salmon cells exposed to copper oxide nanoparticles.

    Science.gov (United States)

    Srikanth, Koigoora; Pereira, Eduarda; Duarte, Armando C; Rao, Janapala Venkateswara

    2016-05-01

    The current study is aimed to study cytotoxicity and oxidative stress mediated changes induced by copper oxide nanoparticles (CuO NPs) in Chinook salmon cells (CHSE-214). To this end, a number of biochemical responses are evaluated in CHSE-214 cells which are as follows [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide] MTT, neutral red uptake (NRU), lactate dehydrogenase (LDH), protein carbonyl (PC), lipid peroxidation (LPO), oxidised glutathione (GSSG), reduced glutathione (GSH), glutathione peroxidase (GPx), glutathione sulfo-transferase (GST), superoxide dismutase (SOD), catalase (CAT), 8-Hydroxy-2'-deoxyguanosine (8-OHdG) and reactive oxygen species (ROS), respectively. The 50 % inhibition concentration (IC50) of CuO NPs to CHSE-214 cells after 24 h exposure was found to be 19.026 μg ml(-1). Viability of cells was reduced by CuO NPs, and the decrease was dose dependent as revealed by the MTT and NRU assay. CHSE-214 cells exposed to CuO NPs induced morphological changes. Initially, cells started to detach from the surface (12 h), followed by polyhedric, fusiform appearance (19 h) and finally the cells started to shrink. Later, the cells started losing their cellular contents leading to their death only after 24 h. LDH, PC, LPO, GSH, GPx, GST, SOD, CAT, 8-OHdG and ROS responses were seen significantly increased with the increase in the concentration of CuO NPs when compared to their respective controls. However, significant decrease in GSSG was perceptible in CHSE-214 cells exposed to CuO NPs in a dose-dependent manner. Our data demonstrated that CuO NPs induced cytotoxicity in CHSE-214 cells through the mediation of oxidative stress. The current study provides a baseline for the CuO NPs-mediated cytotoxic assessment in CHSE-214 cells for the future studies. PMID:26115719

  20. Propranolol sensitizes thyroid cancer cells to cytotoxic effect of vemurafenib.

    Science.gov (United States)

    Wei, Wei-Jun; Shen, Chen-Tian; Song, Hong-Jun; Qiu, Zhong-Ling; Luo, Quan-Yong

    2016-09-01

    Treatment options for advanced metastatic or progressive thyroid cancers are limited. Although targeted therapy specifically inhibiting intracellular kinase signaling pathways has markedly changed the therapeutic landscape, side-effects and resistance of single agent targeted therapy often leads to termination of the treatment. The objective of the present study was to identify the antitumor property of the non-selective β-adrenergic receptor antagonist propranolol for thyroid cancers. Human thyroid cancer cell lines 8505C, K1, BCPAP and BHP27 were used in the present study. Broad β-blocker propranolol and β2-specific antagonist ICI118551, but not β1-specific antagonist atenolol, inhibited the growth of 8505C and K1 cells. Propranolol treatment inhibited growth and induced apoptosis of 8505C cells in vitro and in vivo, which are closely associated with decreased expressions of cyclin D1 and anti-apoptotic Bcl-2. Expression of hexokinase 2 (HK2) and glucose transporter 1 (GLUT1) also decreased following propranolol intervention. 18F-FDG PET/CT imaging of the 8505C xenografts validated shrinkage of the tumors in the propranolol-treated group when compared to the phosphate‑buffered saline treated group. Finally, we found that propranolol can amplify the cytotoxicity of vemurafenib and sensitize thyroid cancer cells to cytotoxic effect of vemurafenib. Our present results suggest that propranolol has potential activity against thyroid cancers and investigation of the combination with targeted molecular therapy for progressive thyroid cancers could be beneficial. PMID:27432558

  1. Cyclosporine A and palmitic acid treatment synergistically induce cytotoxicity in HepG2 cells

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Yi, E-mail: yi.luo@pfizer.com; Rana, Payal; Will, Yvonne

    2012-06-01

    Immunosuppressant cyclosporine A (CsA) treatment can cause severe side effects. Patients taking immunosuppressant after organ transplantation often display hyperlipidemia and obesity. Elevated levels of free fatty acids have been linked to the etiology of metabolic syndromes, nonalcoholic fatty liver and steatohepatitis. The contribution of free fatty acids to CsA-induced toxicity is not known. In this study we explored the effect of palmitic acid on CsA-induced toxicity in HepG2 cells. CsA by itself at therapeutic exposure levels did not induce detectible cytotoxicity in HepG2 cells. Co-treatment of palmitic acid and CsA resulted in a dose dependent increase in cytotoxicity, suggesting that fatty acid could sensitize cells to CsA-induced cytotoxicity at the therapeutic doses of CsA. A synergized induction of caspase-3/7 activity was also observed, indicating that apoptosis may contribute to the cytotoxicity. We demonstrated that CsA reduced cellular oxygen consumption which was further exacerbated by palmitic acid, implicating that impaired mitochondrial respiration might be an underlying mechanism for the enhanced toxicity. Inhibition of c-Jun N-terminal kinase (JNK) attenuated palmitic acid and CsA induced toxicity, suggesting that JNK activation plays an important role in mediating the enhanced palmitic acid/CsA-induced toxicity. Our data suggest that elevated FFA levels, especially saturated FFA such as palmitic acid, may be predisposing factors for CsA toxicity, and patients with underlying diseases that would elevate free fatty acids may be susceptible to CsA-induced toxicity. Furthermore, hyperlipidemia/obesity resulting from immunosuppressive therapy may aggravate CsA-induced toxicity and worsen the outcome in transplant patients. -- Highlights: ► Palmitic acid and cyclosporine (CsA) synergistically increased cytotoxicity. ► The impairment of mitochondrial functions may contribute to the enhanced toxicity. ► Inhibition of JNK activity attenuated

  2. Cyclosporine A and palmitic acid treatment synergistically induce cytotoxicity in HepG2 cells

    International Nuclear Information System (INIS)

    Immunosuppressant cyclosporine A (CsA) treatment can cause severe side effects. Patients taking immunosuppressant after organ transplantation often display hyperlipidemia and obesity. Elevated levels of free fatty acids have been linked to the etiology of metabolic syndromes, nonalcoholic fatty liver and steatohepatitis. The contribution of free fatty acids to CsA-induced toxicity is not known. In this study we explored the effect of palmitic acid on CsA-induced toxicity in HepG2 cells. CsA by itself at therapeutic exposure levels did not induce detectible cytotoxicity in HepG2 cells. Co-treatment of palmitic acid and CsA resulted in a dose dependent increase in cytotoxicity, suggesting that fatty acid could sensitize cells to CsA-induced cytotoxicity at the therapeutic doses of CsA. A synergized induction of caspase-3/7 activity was also observed, indicating that apoptosis may contribute to the cytotoxicity. We demonstrated that CsA reduced cellular oxygen consumption which was further exacerbated by palmitic acid, implicating that impaired mitochondrial respiration might be an underlying mechanism for the enhanced toxicity. Inhibition of c-Jun N-terminal kinase (JNK) attenuated palmitic acid and CsA induced toxicity, suggesting that JNK activation plays an important role in mediating the enhanced palmitic acid/CsA-induced toxicity. Our data suggest that elevated FFA levels, especially saturated FFA such as palmitic acid, may be predisposing factors for CsA toxicity, and patients with underlying diseases that would elevate free fatty acids may be susceptible to CsA-induced toxicity. Furthermore, hyperlipidemia/obesity resulting from immunosuppressive therapy may aggravate CsA-induced toxicity and worsen the outcome in transplant patients. -- Highlights: ► Palmitic acid and cyclosporine (CsA) synergistically increased cytotoxicity. ► The impairment of mitochondrial functions may contribute to the enhanced toxicity. ► Inhibition of JNK activity attenuated

  3. Cytotoxic activity of marine algae against cancerous cells

    Directory of Open Access Journals (Sweden)

    Élica A. C. Guedes

    2013-08-01

    Full Text Available This paper presents an investigation on the cytotoxic activity in human tumor cell from dichloromethane, chloroform, methanol, ethanol, water extracts, and hexane and chloroform fractions from green, brown and red algae collected at Riacho Doce Beach, north coast of Alagoas, Brazil, against the cancer cells K562 (chronic myelocytic leukemia, HEp-2 (laryngeal epidermoid carcinoma and NCI-H292 (human lung mucoepidermoid carcinoma through the MTT colorimetric method. The dichloromethane extract and chloroform fraction of Hypnea musciformis showed the best cytotoxic activity against K562 (3.8±0.2 µg.mL-1 and 6.4±0.4 µg.mL-1, respectively. Dichloromethane extracts of Dictyota dichotoma (16.3±0.3 µg.mL-1 and the chloroform fraction of H. musciformis (6.0±0.03 µg.mL-1 and chloroform fraction of P. gymnospora (8.2±0.4 were more active against HEp-2 as well as ethanol extracts of P. gymnospora (15.9±2.8 µg.mL-1 and chloroform fraction of H. musciformis (15.0±1.3 µg.mL-1 against the cell NCI-H292. The constituents with higher anticancer action are present in the extracts of dichloromethane and chloroform and in the chloroform fraction of H. musciformis, Digenea simplex, P. gymnospora, and D.dichotoma. In the case of the seaweed S. vulgare, the anticancer constituents are present in the aqueous extract.

  4. Pathogenesis of Streptococcus urinary tract infection depends on bacterial strain and β-hemolysin/cytolysin that mediates cytotoxicity, cytokine synthesis, inflammation and virulence.

    Science.gov (United States)

    Leclercq, Sophie Y; Sullivan, Matthew J; Ipe, Deepak S; Smith, Joshua P; Cripps, Allan W; Ulett, Glen C

    2016-01-01

    Streptococcus agalactiae can cause urinary tract infection (UTI) including cystitis and asymptomatic bacteriuria (ABU). The early host-pathogen interactions that occur during S. agalactiae UTI and subsequent mechanisms of disease pathogenesis are poorly defined. Here, we define the early interactions between human bladder urothelial cells, monocyte-derived macrophages, and mouse bladder using uropathogenic S. agalactiae (UPSA) 807 and ABU-causing S. agalactiae (ABSA) 834 strains. UPSA 807 adhered, invaded and killed bladder urothelial cells more efficiently compared to ABSA 834 via mechanisms including low-level caspase-3 activation, and cytolysis, according to lactate dehydrogenase release measures and cell viability. Severe UPSA 807-induced cytotoxicity was mediated entirely by the bacterial β-hemolysin/cytolysin (β-H/C) because an β-H/C-deficient UPSA 807 isogenic mutant, UPSA 807ΔcylE, was not cytotoxic in vitro; the mutant was also significantly attenuated for colonization in the bladder in vivo. Analysis of infection-induced cytokines, including IL-8, IL-1β, IL-6 and TNF-α in vitro and in vivo revealed that cytokine and chemokine responses were dependent on expression of β-H/C that also elicited severe bladder neutrophilia. Thus, virulence of UPSA 807 encompasses adhesion to, invasion of and killing of bladder cells, pro-inflammatory cytokine/chemokine responses that elicit neutrophil infiltration, and β-H/C-mediated subversion of innate immune-mediated bacterial clearance from the bladder. PMID:27383371

  5. IN VITRO CYTOTOXICITY OF MADHUCA INDICA AGAINST DIFFERENT HUMAN CANCER CELL LINES

    OpenAIRE

    Satish K. Verma et al.

    2012-01-01

    Cancer is a public health problem all over the world. Large number of plants and their isolated constituents has been shown to potential anticancer activity. Ethanolic whole plant extract of Madhuca indica showed in vitro cytotoxicity against different human cancer cell lines such as lung, neuroblastima, and colon. There was no growth of inhibition recorded against liver cancer cell line. Sulforhodamine B dye (SRB) assay was done for in vitro cytotoxicity test assay. The in vitro cytotoxicity...

  6. Effects of Ganoderma lucidum polysaccharides on proliferation and cytotoxicity of cytokine-induced killer cells

    Institute of Scientific and Technical Information of China (English)

    Xiao-ling ZHU; Zhi-bin LIN

    2005-01-01

    Aim: To study the effects (and the mechanisms thereof) of Ganoderma lucidum polysaccharides (Gl-PS) on the proliferation and the anti-tumor activity of cytokineinduced killer (CIK) cells, and to make use of CIK cells as a means to investigate the interactions between Gl-PS and cytokines. Methods: CIK cells were prepared by using the standard protocol as a positive control. Experimental groups also underwent the standard protocol, except that Gl-PS (400 mg/L or 100 mg/L) was added and the dose of anti-CD3 and interleukin-2 they received was reduced by 50% and 75%, respectively. For negative controls, Gl- PS in the experimental protocol was replaced with soluble starch or methylcellulose (400 mg/L or 100 mg/L).CIK cell proliferation, cytotoxicity, and phenotype weredetermined by using the Trypan blue exclusion method, MTT assay, and flow cytometry. Results: By synergizing cytokines, Gl-PS (400 mg/L or 100 mg/L) could decrease the amount of cytokine in lymphokine activated killer (LAK) cells and CIK cells culture, but had no significant effect on the proliferation, cytotoxicity, or phenotype of LAK cells, or CIK cells induced by cytokines at higher doses alone, in which CIK cells expanded about 80-fold and the main effectors, CD3+NK1.1+ cells, expanded by more than 15%. The cytotoxicity of CIK cells in experimental groups was 79.3%±4.7%, 76.9%±6.8% versus the positive control 80.7%±6.8% against P815 (P>0.05)and 88.9%±5.5%, 84.7%±7.9% versus the positive control 89.8%±4.5% against YAC-1 (P>0.05). The activity of Gl-PS could mostly be blocked by anti-CR3.Conclusion: Gl-PS was shown to be a promising biological response modifier and immune potentiator. The effect of Gl-PS on CIK cells is possibly mediated primarily through complement receptor type 3.

  7. PDMS/glass microfluidic cell culture system for cytotoxicity tests and cells passage

    DEFF Research Database (Denmark)

    Ziolkowska, K.; Jedrych, E.; Kwapiszewski, R.; Lopacinska, Joanna M.; Skolimowski, Maciej; Chudy, M.

    2010-01-01

    In this paper, hybrid (PDMS/glass) microfluidic cell culture system (MCCS) integrated with the concentration gradient generator (CGG) is presented. PDMS gas permeability enabled cells' respiration in the fabricated microdevices and excellent glass hydrophilicity allowed successful cells' seeding....... The human lung carcinoma cells (A549) were cultured in the microdevice for several days. The growth and proliferation of cells was monitored using an inverted fluorescence microscope. After the cells' confluence was achieved in the microchambers, the novel method of cells' passaging in the designed...... microdevice was developed and successfully tested. The MCCS microdevice is fully reusable, i.e. it can be used several times for various cell culture and cytotoxic experiments. The suitability of designed MCCS for cell-based cytotoxicity assay application was verified using 1,4-dioxane as a model toxic agent...

  8. IFN-γ mediates graft-versus-breast cancer effects via enhancing cytotoxic T lymphocyte activity.

    Science.gov (United States)

    Zhao, Qianjie; Tong, Lingling; He, Ningning; Feng, Guowei; Leng, Liang; Sun, Weijun; Xu, Yang; Wang, Yuebing; Xiang, Rong; Li, Zongjin

    2014-08-01

    Previous studies have demonstrated the beneficial effect of graft-versus-tumor (GVT) following hematopoietic stem cell transplantation (HSCT) on the incidence of leukemia relapse and the overall survival rate of patients with leukemia; however, detailed mechanisms underlying the effects GVT exhibits on solid tumors following allogeneic HSCT are yet to be elucidated. The aim of the present study was to investigate the immune mechanism underlying the effect of interferon (IFN)-γ on GVT following allogeneic HSCT in breast cancer therapy. An in situ breast cancer mouse model was established by injecting 5×10(4) 4T1 cells into the mammary fat pads of BALB/c mice. The 4T1 cells were transfected with the firefly luciferase reporter gene in order to monitor the tumor progression in real time. An allogeneic HSCT model was then established by transplanting bone marrow mononuclear cells from C57BL/6 mice to the BALB/c mice. To investigate the influence of T lymphocyte proliferation following allogeneic bone marrow transplantation, the levels of CD3(+)CD8(+) cytotoxic T lymphocytes (CTLs) and CD4(+)CD25(+) regulatory T cells were determined. In addition, IFN-γ and granzyme B expression levels in splenic lymphocytes were analyzed using flow cytometry. Allogeneic HSCT was found to significantly promote the proliferation and cytotoxicity of CTLs and suppress the growth of breast cancer. Furthermore, the secretory levels of IFN-γ and granzyme B by T cells were elevated following allogeneic HSCT. These results indicated that alloreactive T cells increased the secretion of IFN-γ, which promoted the alloresponse of donor CTLs. In addition, the CTLs produced granzyme B, which exerted a tumor suppressive effect. PMID:25009582

  9. A flagellin-derived toll-like receptor 5 agonist stimulates cytotoxic lymphocyte-mediated tumor immunity.

    Directory of Open Access Journals (Sweden)

    Nicholas D Leigh

    Full Text Available Toll-like receptor (TLR mediated recognition of pathogen associated molecular patterns allows the immune system to rapidly respond to a pathogenic insult. The "danger context" elicited by TLR agonists allows an initially non-immunogenic antigen to become immunogenic. This ability to alter environment is highly relevant in tumor immunity, since it is inherently difficult for the immune system to recognize host-derived tumors as immunogenic. However, immune cells may have encountered certain TLR ligands associated with tumor development, yet the endogenous stimulation is typically not sufficient to induce spontaneous tumor rejection. Of special interest are TLR5 agonists, because there are no endogenous ligands that bind TLR5. CBLB502 is a pharmacologically optimized TLR5 agonist derived from Salmonella enterica flagellin. We examined the effect of CBLB502 on tumor immunity using two syngeneic lymphoma models, both of which do not express TLR5, and thus do not directly respond to CBLB502. Upon challenge with the T-cell lymphoma RMAS, CBLB502 treatment after tumor inoculation protects C57BL/6 mice from death caused by tumor growth. This protective effect is both natural killer (NK cell- and perforin-dependent. In addition, CBLB502 stimulates clearance of the B-cell lymphoma A20 in BALB/c mice in a CD8(+ T cell-dependent fashion. Analysis on the cellular level via ImageStream flow cytometry reveals that CD11b(+ and CD11c(+ cells, but neither NK nor T cells, directly respond to CBLB502 as determined by NFκB nuclear translocation. Our findings demonstrate that CBLB502 stimulates a robust antitumor response by directly activating TLR5-expressing accessory immune cells, which in turn activate cytotoxic lymphocytes.

  10. Adjuvant antiproliferative and cytotoxic effect of aloin in irradiated HeLaS3 cells

    International Nuclear Information System (INIS)

    Naturally occurring phytoanthracycline, aloin, was used to radiosensitize HeLaS3 human cervix carcinoma cells. The results indicated that the cytotoxic adjuvant effect of aloin was synergistic with IR at all drug concentrations and comparable to the cytotoxicity of 5-10Gy IR alone. Radiosensitization of HeLaS3 cells was achieved by 60μM aloin which reduced IC50 dose of IR from 3.4- to 2Gy. The cell damage by both agents compromised cell capacity to conduct programmed cell death by apoptosis, and led to the synergic cytotoxic cell death by necrosis. (author)

  11. Concanavalin A-induced activation of lymphocytic choriomeningitis virus memory lymphocytes into specifically cytotoxic T cells

    DEFF Research Database (Denmark)

    Marker, O; Thomsen, Allan Randrup; Andersen, G T

    1977-01-01

    When spleen cells, which have been primed to Lymphocytic Choriomeningitis (LCM) virus during a primary infection several months previously, are stimulated in vitro with Con A. highly specific secondary cytotoxic effector cells are generated. The degree of cytotoxicity revealed by such Con A...

  12. Identification of the Immunodominant H-2Kk-Restricted Cytotoxic T-Cell Epitope in the Borna Disease Virus Nucleoprotein

    OpenAIRE

    Schamel, Karin; Staeheli, Peter; Hausmann, Jürgen

    2001-01-01

    Borna disease virus (BDV)-induced immunopathology in mice is most prominent in strains carrying the major histocompatibility complex H-2k allele and is mediated by CD8+ T cells that are directed against the viral nucleoprotein p40. We now identified the highly conserved octamer peptide TELEISSI, located between amino acid residues 129 and 136 of BDV p40, as a potent H-2Kk-restricted cytotoxic T-cell (CTL) epitope. When added to the culture medium of L929 target cells, TELEISSI conferred sensi...

  13. Polycation-mediated integrated cell death processes

    DEFF Research Database (Denmark)

    Parhamifar, Ladan; Andersen, Helene; Wu, Linping;

    2014-01-01

    standard. PEIs are highly efficient transfectants, but depending on their architecture and size they induce cytotoxicity through different modes of cell death pathways. Here, we briefly review dynamic and integrated cell death processes and pathways, and discuss considerations in cell death assay design...

  14. Cytotoxic Effects of Fascaplysin against Small Cell Lung Cancer Cell Lines

    Directory of Open Access Journals (Sweden)

    Gerhard Hamilton

    2014-03-01

    Full Text Available Fascaplysin, the natural product of a marine sponge, exhibits anticancer activity against a broad range of tumor cells, presumably through interaction with DNA, and/or as a highly selective cyclin-dependent kinase 4 (CDK4 inhibitor. In this study, cytotoxic activity of fascaplysin against a panel of small cell lung cancer (SCLC cell lines and putative synergism with chemotherapeutics was investigated. SCLC responds to first-line chemotherapy with platinum-based drugs/etoposide, but relapses early with topotecan remaining as the single approved therapeutic agent. Fascaplysin was found to show high cytotoxicity against SCLC cells and to induce cell cycle arrest in G1/0 at lower and S-phase at higher concentrations, respectively. The compound generated reactive oxygen species (ROS and induced apoptotic cell death in the chemoresistant NCI-H417 SCLC cell line. Furthermore, fascaplysin revealed marked synergism with the topoisomerase I-directed camptothecin and 10-hydroxy-camptothecin. The Poly(ADP-ribose-Polymerase 1 (PARP1 inhibitor BYK 204165 antagonized the cytotoxic activity of fascaplysin, pointing to the involvement of DNA repair in response to the anticancer activity of the drug. In conclusion, fascaplysin seems to be suitable for treatment of SCLC, based on high cytotoxic activity through multiple routes of action, affecting topoisomerase I, integrity of DNA and generation of ROS.

  15. Cytotoxicity of antimicrobial photodynamic inactivation on epithelial cells when co-cultured with Candida albicans.

    Science.gov (United States)

    Pellissari, Claudia Viviane Guimarães; Pavarina, Ana Claudia; Bagnato, Vanderlei Salvador; Mima, Ewerton Garcia de Oliveira; Vergani, Carlos Eduardo; Jorge, Janaina Habib

    2016-05-11

    This study assessed the cytotoxicity of antimicrobial Photodynamic Inactivation (aPDI), mediated by curcumin, using human keratinocytes co-cultured with Candida albicans. Cells and microorganisms were grown separately for 24 hours and then kept in contact for an additional 24 hours. After this period, aPDI was applied. The conditions tested were: P+L+ (experimental group aPDI); P-L+ (light emitting diode [LED] group); P+L- (curcumin group); and P-L- (cells in co-culture without curcumin nor LED). In addition, keratinocytes and C. albicans were grown separately, were not placed in the co-culture and did not receive aPDI (control group). Cell proliferation was assessed using Alamar Blue, MTT, XTT and CFU tests. Qualitative and quantitative analyses were performed. Analysis of variance (ANOVA) was applied to the survival percentages of cells compared to the control group (considered as 100% viability), complemented by multiple comparisons using Tukey's test. A 5% significance level was adopted. The results of this study showed no interference in the metabolism of the cells in co-culture, since no differences were observed between the control group (cultured cells by themselves) and the P-L- group (co-culture cells without aPDI). The aPDI group reached the highest reduction (p = 0.009), which was equivalent to 1.7 log10 when compared to the control group. The P+L-, P-L+, P-L- and control groups were not statistically different (ρ > 0.05). aPDI inhibited the growth of keratinocytes and C. albicans in all tests, so the therapy was considered slightly (inhibition between 25 and 50% compared to the control group) to moderately (inhibition between 50 and 75% compared to the control group) cytotoxic. PMID:27110908

  16. Dopamine-mediated oxidation of methionine 127 in α-synuclein causes cytotoxicity and oligomerization of α-synuclein.

    Directory of Open Access Journals (Sweden)

    Kazuhiro Nakaso

    Full Text Available Parkinson's disease (PD is a neurodegenerative disorder characterized by the selective loss of dopaminergic neurons and the presence of Lewy bodies. Many recent studies focused on the interaction between α-synuclein (α-syn and dopamine in the pathogenesis of PD, and fluorescent anisotropy suggested that the C-terminal region of α-syn may be a target for modification by dopamine. However, it is not well understood why PD-related pathogenesis occurs selectively in dopaminergic neurons. We investigated the interaction between dopamine and α-syn with regard to cytotoxicity. A soluble oligomer was formed by co-incubating α-syn and dopamine in vitro. To clarify the effect of dopamine on α-syn in cells, we generated PC12 cells expressing human α-syn, as well as the α-syn mutants, M116A, Y125D, M127A, S129A, and M116A/M127A, in a tetracycline-inducible manner (PC12-TetOFF-α-syn. Overexpression of wildtype α-syn in catecholaminergic PC12 cells decreased cell viability in long-term cultures, while a competitive inhibitor of tyrosine hydroxylase blocked this vulnerability, suggesting that α-syn-related cytotoxicity is associated with dopamine metabolism. The vulnerabilities of all mutant cell lines were lower than that of wildtype α-syn-expressing cells. Moreover, α-syn containing dopamine-mediated oxidized methionine (Met(O was detected in PC12-TetOFF-α-syn. Met(O was lower in methionine mutant cells, especially in the M127A or M116A/M127A mutants, but also in the Y125D and S129A mutants. Co-incubation of dopamine and the 125YEMPS129 peptide enhanced the production of H2O2, which may oxidize methionine residues and convert them to Met(O. Y125- or S129-lacking peptides did not enhance the dopamine-related production of H2O2. Our results suggest that M127 is the major target for oxidative modification by dopamine, and that Y125 and S129 may act as enhancers of this modification. These results may describe a mechanism of dopaminergic neuron

  17. Cytotoxic effects of curcumin in human retinal pigment epithelial cells.

    Directory of Open Access Journals (Sweden)

    Margrit Hollborn

    Full Text Available BACKGROUND: Curcumin from turmeric is an ingredient in curry powders. Due to its antiinflammatory, antioxidant and anticarcinogenic effects, curcumin is a promising drug for the treatment of cancer and retinal diseases. We investigated whether curcumin alters the viability and physiological properties of human retinal pigment epithelial (RPE cells in vitro. METHODOLOGY/PRINCIPAL FINDINGS: Cellular proliferation was investigated with a bromodeoxy-uridine immunoassay, and chemotaxis was investigated with a Boyden chamber assay. Cell viability was determined by trypan blue exclusion. Apoptosis and necrosis rates were determined with a DNA fragmentation ELISA. Gene expression was determined by real-time PCR, and secretion of VEGF and bFGF was examined with ELISA. The phosphorylation level of proteins was revealed by Western blotting. The proliferation of RPE cells was slightly increased by curcumin at 10 µM and strongly reduced by curcumin above 50 µM. Curcumin at 50 µM increased slightly the chemotaxis of the cells. Curcumin reduced the expression and secretion of VEGF under control conditions and abolished the VEGF secretion induced by PDGF and chemical hypoxia. Whereas low concentrations of curcumin stimulated the expression of bFGF and HGF, high concentrations caused downregulation of both factors. Curcumin decreased dose-dependently the viability of RPE cells via induction of early necrosis (above 10 µM and delayed apoptosis (above 1 µM. The cytotoxic effect of curcumin involved activation of caspase-3 and calpain, intracellular calcium signaling, mitochondrial permeability, oxidative stress, increased phosphorylation of p38 MAPK and decreased phosphorylation of Akt protein. CONCLUSION: It is concluded that curcumin at concentrations described to be effective in the treatment of tumor cells and in inhibiting death of retinal neurons (∼10 µM has adverse effects on RPE cells. It is suggested that, during the intake of curcumin as

  18. Targeting CD47-SIRPα interactions for potentiating therapeutic antibody-mediated tumor cell destruction by phagocytes

    OpenAIRE

    Zhao, X.W.

    2014-01-01

    The primary aim of the studies described in this thesis was to investigate the role of CD47-SIRPα interactions in therapeutic antibody-dependent tumor cell destruction by human phagocytes and also explore the killing mechanism(s) by which human phagocytes, and in particular human neutrophils, mediate therapeutic antibody-dependent cytotoxicity towards cancer cells.

  19. Simultaneous measurement of NK cell cytotoxicity against two target cell lines labelled with fluorescent lanthanide chelates.

    Science.gov (United States)

    Lövgren, J; Blomberg, K

    1994-07-12

    We describe a cytotoxicity assay which permits the simultaneous measurement of natural killer cell activity against two different cell lines. The target cell lines are labelled either with a fluorescent europium chelate or with a fluorescent terbium chelate and cell death is quantified by measuring the chelate release. K-562, Molt4 and Daudi cell lines have been used as targets. The release of the two chelates from the target cells can be detected with the help of time resolved fluorometry. As the measurements are made after background fluorescence has decayed no additional steps are needed to correct for the background from the medium. The assay procedure used for measurement of cytotoxicity against two target cell lines is very similar to the widely used 51Cr release assay. PMID:8034979

  20. Sustained Release and Cytotoxicity Evaluation of Carbon Nanotube-Mediated Drug Delivery System for Betulinic Acid

    Directory of Open Access Journals (Sweden)

    Julia M. Tan

    2014-01-01

    Full Text Available Carbon nanotubes (CNTs have been widely utilized as a novel drug carrier with promising future applications in biomedical therapies due to their distinct characteristics. In the present work, carboxylic acid-functionalized single-walled carbon nanotubes (f-SWCNTs were used as the starting material to react with anticancer drug, BA to produce f-SWCNTs-BA conjugate via π-π stacking interaction. The conjugate was extensively characterized for drug loading capacity, physicochemical properties, surface morphology, drug releasing characteristics, and cytotoxicity evaluation. The results indicated that the drug loading capacity was determined to be around 20 wt% and this value has been verified by thermogravimetric analysis. The binding of BA onto the surface of f-SWCNTs was confirmed by FTIR and Raman spectroscopies. Powder XRD analysis showed that the structure of the conjugate was unaffected by the loading of BA. The developed conjugate was found to release the drug in a controlled manner with a prolonged release property. According to the preliminary in vitro cytotoxicity studies, the conjugate was not toxic in a standard fibroblast cell line, and anticancer activity was significantly higher in A549 than HepG2 cell line. This study suggests that f-SWCNTs could be developed as an efficient drug carrier to conjugate drugs for pharmaceutical applications in cancer chemotherapies.

  1. Streptozotocin-Induced Cytotoxicity, Oxidative Stress and Mitochondrial Dysfunction in Human Hepatoma HepG2 Cells

    Directory of Open Access Journals (Sweden)

    Haider Raza

    2012-05-01

    Full Text Available Streptozotocin (STZ is an antibiotic often used in the treatment of different types of cancers. It is also highly cytotoxic to the pancreatic beta-cells and therefore is commonly used to induce experimental type 1 diabetes in rodents. Resistance towards STZ-induced cytotoxicity in cancer cells has also been reported. Our previous studies have reported organ-specific toxicity and metabolic alterations in STZ-induced diabetic rats. STZ induces oxidative stress and metabolic complications. The precise molecular mechanism of STZ-induced toxicity in different tissues and carcinomas is, however, unclear. We have, therefore, investigated the mechanism of cytotoxicity of STZ in HepG2 hepatoma cells in culture. Cells were treated with different doses of STZ for various time intervals and the cytotoxicity was studied by observing the alterations in oxidative stress, mitochondrial redox and metabolic functions. STZ induced ROS and RNS formation and oxidative stress as measured by an increase in the lipid peroxidation as well as alterations in the GSH-dependent antioxidant metabolism. The mitochondria appear to be a highly sensitive target for STZ toxicity. The mitochondrial membrane potential and enzyme activities were altered in STZ treated cells resulting in the inhibition of ATP synthesis. ROS-sensitive mitochondrial aconitase activity was markedly inhibited suggesting increased oxidative stress in STZ-induced mitochondrial toxicity. These results suggest that STZ-induced cytotoxicity in HepG2 cells is mediated, at least in part, by the increase in ROS/RNS production, oxidative stress and mitochondrial dysfunction. Our study may be significant for better understanding the mechanisms of STZ action in chemotherapy and drug induced toxicity.

  2. Cell-specific oxidative stress and cytotoxicity after wildfire coarse particulate matter instillation into mouse lung

    International Nuclear Information System (INIS)

    Our previous work has shown that coarse particulate matter (PM10-2.5) from wildfire smoke is more toxic to lung macrophages on an equal dose (by mass) basis than coarse PM isolated from normal ambient air, as evidenced by decreased numbers of macrophages in lung lavage fluid 6 and 24 hours after PM instillation into mouse lungs in vivo and by cytotoxicity to a macrophage cell line observed directly in vitro. We hypothesized that pulmonary macrophages from mice instilled with wildfire coarse PM would undergo more cytotoxicity than macrophages from controls, and that there would be an increase in oxidative stress in their lungs. Cytotoxicity was quantified as decreased viable macrophages and increased percentages of dead macrophages in the bronchoalveolar lavage fluid (BALF) of mice instilled with wildfire coarse PM. At 1 hour after PM instillation, we observed both decreased numbers of viable macrophages and increased dead macrophage percentages as compared to controls. An increase in free isoprostanes, an indicator of oxidative stress, from control values of 28.1 ± 3.2 pg/mL to 83.9 ± 12.2 pg/mL was observed a half-hour after PM instillation. By 1 hour after PM instillation, isoprostane values had returned to 30.4 ± 7.6 pg/mL, not significantly different from control concentrations. Lung sections from mice instilled with wildfire coarse PM showed rapid Clara cell responses, with decreased intracellular staining for the Clara cell secretory protein CCSP 1 hour after wildfire PM instillation. In conclusion, very rapid cytotoxicity occurs in pulmonary macrophages and oxidative stress responses are seen 0.5–1 hour after wildfire coarse PM instillation. These results define early cellular and biochemical events occurring in vivo and support the hypothesis that oxidative stress-mediated macrophage toxicity plays a key role in the initial response of the mouse lung to wildfire PM exposure. -- Highlights: ► We studied very early events (0.5–1 hour) after giving

  3. The susceptibility to cytotoxic T lymphocyte mediated lysis of chemically induced sarcomas from immunodeficient and normal mice

    DEFF Research Database (Denmark)

    Svane, I M; Engel, A M; Thomsen, Allan Randrup;

    1997-01-01

    tested for susceptibility to cytolysis by virus specific cytotoxic T cells. Tumour cells originating from tumours induced in immunocompetent C.B.-17 mice presented virus antigen more efficiently than tumour cells from immunodeficient SCID mice. No significant difference in virus antigen presentation was...

  4. Rhinovirus infection induces cytotoxicity and delays wound healing in bronchial epithelial cells

    OpenAIRE

    Constantopoulos Andreas G; Skevaki Chrysanthi L; Gourgiotis Dimitrios; Psarras Stelios; Bossios Apostolos; Saxoni-Papageorgiou Photini; Papadopoulos Nikolaos G

    2005-01-01

    Abstract Background Human rhinoviruses (RV), the most common triggers of acute asthma exacerbations, are considered not cytotoxic to the bronchial epithelium. Recent observations, however, have questioned this knowledge. The aim of this study was to evaluate the ability of RV to induce epithelial cytotoxicity and affect epithelial repair in-vitro. Methods Monolayers of BEAS-2B bronchial epithelial cells, seeded at different densities were exposed to RV serotypes 1b, 5, 7, 9, 14, 16. Cytotoxic...

  5. Differential effects of radical scavengers on X-ray-induced mutation and cytotoxicity in human cells

    International Nuclear Information System (INIS)

    The cytotoxic and mutagenic effects of X irradiation on a human lymphoblast cell line were examined in the presence of two radioprotective agents which modulate damage to DNA. The cells were treated with X rays alone or in the presence of either dimethyl sulfoxide or cysteamine. Surviving fraction and mutation to trifluorothymidine resistance (tk locus) and to 6-thioguanine resistance (hgprt locus) were measured. Survival was enhanced when the cells were irradiated in the presence of dimethyl sulfoxide; the D0 rose from 58 to 107 rad. However, at both genetic loci the induced mutant fractions were identical in the presence or absence of dimethyl sulfoxide. Survival was enhanced to a greater degree when the cells were irradiated in the presence of cysteamine; the D0 rose from 58 to 200 rad. Cysteamine also protected the cells from X-ray-induced mutation; the frequencies of X-ray-induced mutation at both the tk and hgprt loci were reduced by 50-75%. No protective effects were observed unless dimethyl sulfoxide or cysteamine was present during irradiation. These findings are discussed in terms of the hypothesis that, unlike for cell killing, radiation-induced mutagenesis in human lymphoblast cells is not mediated by the actions of aqueous free radicals, but rather by the direct effects of ionizing radiation

  6. Spred2 is involved in imatinib-induced cytotoxicity in chronic myeloid leukemia cells

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Xiao-Yun; Yang, Yue-Feng; Wu, Chu-Tse; Xiao, Feng-Jun; Zhang, Qun-Wei [Department of Experimental Hematology, Beijing Institute of Radiation Medicine, Beijing 100850 (China); Ma, Xiao-Ni [Lanzhou University of Technology, Lanzhou 730050 (China); Li, Qing-Fang; Yan, Jun [Department of Experimental Hematology, Beijing Institute of Radiation Medicine, Beijing 100850 (China); Wang, Hua, E-mail: wanghualjh@gmail.com [Department of Experimental Hematology, Beijing Institute of Radiation Medicine, Beijing 100850 (China); Wang, Li-Sheng, E-mail: wangls@nic.bmi.ac.cn [Department of Experimental Hematology, Beijing Institute of Radiation Medicine, Beijing 100850 (China)

    2010-03-19

    Spreds, a recently established class of negative regulators of the Ras-ERK (extracellular signal-regulated kinase) pathway, are involved in hematogenesises, allergic disorders and tumourigenesis. However, their role in hematologic neoplasms is largely unknown. Possible effects of Spreds on other signal pathways closely related to Ras-ERK have been poorly investigated. In this study, we investigated the in vitro effects of Spred2 on chronic myeloid leukemia (CML) cells. In addition to inhibiting the well-established Ras-ERK cascade, adenovirus-mediated Spred2 over-expression inhibits constitutive and stem cell factor (SCF)-stimulated sphingosine kinase-1 (SPHK1) and Mcl-1 expression, as well as inhibiting proliferation and inducing apoptosis in CML cells. In K562 cells and primary CML cells, imatinib induces endogenous Spred2 expression. Spred2 silencing by stable RNA interference partly protects K562 cells against imatinib-induced apoptosis. Together, these data implicate Spred2 in imatinib-induced cytotoxicity in CML cells, possibly by inhibiting the Ras-ERK cascade and the pro-survival signaling molecules SPHK1 and Mcl-1. These findings reveal potential targets for selective therapy of CML.

  7. Spred2 is involved in imatinib-induced cytotoxicity in chronic myeloid leukemia cells

    International Nuclear Information System (INIS)

    Spreds, a recently established class of negative regulators of the Ras-ERK (extracellular signal-regulated kinase) pathway, are involved in hematogenesises, allergic disorders and tumourigenesis. However, their role in hematologic neoplasms is largely unknown. Possible effects of Spreds on other signal pathways closely related to Ras-ERK have been poorly investigated. In this study, we investigated the in vitro effects of Spred2 on chronic myeloid leukemia (CML) cells. In addition to inhibiting the well-established Ras-ERK cascade, adenovirus-mediated Spred2 over-expression inhibits constitutive and stem cell factor (SCF)-stimulated sphingosine kinase-1 (SPHK1) and Mcl-1 expression, as well as inhibiting proliferation and inducing apoptosis in CML cells. In K562 cells and primary CML cells, imatinib induces endogenous Spred2 expression. Spred2 silencing by stable RNA interference partly protects K562 cells against imatinib-induced apoptosis. Together, these data implicate Spred2 in imatinib-induced cytotoxicity in CML cells, possibly by inhibiting the Ras-ERK cascade and the pro-survival signaling molecules SPHK1 and Mcl-1. These findings reveal potential targets for selective therapy of CML.

  8. Cytotoxicity against KB and NCI-H187 cell lines of modified flavonoids from Kaempferia parviflora.

    Science.gov (United States)

    Yenjai, Chavi; Wanich, Suchana

    2010-05-01

    Flavones 1-4 isolated from Kaempferia parviflora were used for structural modification. Sixteen flavonoid derivatives, including four new derivatives, were synthesized and evaluated for cytotoxicity against KB and NCI-H187 cell lines. Flavanones 2a-4a demonstrated higher cytotoxic activity than the parent compounds. Cytotoxicity against KB cell line of oxime 1c was about 7 times higher than the ellipticine standard. Interestingly, oximes 1c and 2c exhibited highly potent cytotoxicity against NCI-H187 cell line with IC(50) values of 0.014 and 0.23 microM, respectively. Oximes 4c and 5c showed strong cytotoxicity against NCI-H187 cell line with IC(50) values of 4.04 and 2.32 microM, respectively. PMID:20362442

  9. The aryl hydrocarbon receptor: differential contribution to T helper 17 and T cytotoxic 17 cell development.

    Directory of Open Access Journals (Sweden)

    Mark D Hayes

    Full Text Available The aryl hydrocarbon receptor (AhR has been shown to be required for optimal Thelper (Th 17 cell activation. Th17 cells provide immunity against extracellular pathogens and are implicated in autoimmune diseases. Herein, the role of the AhR in cytokine production by Th17, and by the analogous population of T cytotoxic (Tc17 cells, has been examined. Lymph node Tc (CD8(+ and Th (CD4(+ cells were isolated by negative selection from naive AhR(+/- and AhR(-/- mice and polarised to Tc1/Th1 or Tc17/Th17 phenotypes with appropriate cytokines. Cell differentiation was assessed as a function of mRNA and protein (ELISA and flow cytometry expression for interferon (IFN-γ and for key Th17 cytokines. In AhR(+/- mice, Th17 cells displayed an exclusive IL-17 profile, which was markedly inhibited by a selective AhR antagonist to levels observed in AhR knockout mice. Addition of the natural AhR agonist 6-formylindolo[3,2-b]carbazole (FICZ markedly enhanced Th17 cell activity in the heterozygotes. In contrast, Tc17 cells polarised into 3 distinct subsets: producing either IL-17 or IFN-γ alone, or both cytokines. Blocking AhR was also detrimental to Tc17 development, with reduced responses recorded in AhR(-/- mice and antagonist-mediated reduction of IL-17 expression in the heterozygotes. However, Tc17 cells were largely refractory to exogenous FICZ, presumably because Tc17 cells express baseline AhR mRNA, but unlike Th17 cells, there is no marked up-regulation during polarisation. Thus, Th17 cell development is more dependent upon AhR activation than is Tc17 cell development, suggesting that endogenous AhR ligands play a much greater role in driving Th17 cell responses.

  10. The aryl hydrocarbon receptor: differential contribution to T helper 17 and T cytotoxic 17 cell development.

    Science.gov (United States)

    Hayes, Mark D; Ovcinnikovs, Vitalijs; Smith, Andrew G; Kimber, Ian; Dearman, Rebecca J

    2014-01-01

    The aryl hydrocarbon receptor (AhR) has been shown to be required for optimal Thelper (Th) 17 cell activation. Th17 cells provide immunity against extracellular pathogens and are implicated in autoimmune diseases. Herein, the role of the AhR in cytokine production by Th17, and by the analogous population of T cytotoxic (Tc)17 cells, has been examined. Lymph node Tc (CD8(+)) and Th (CD4(+)) cells were isolated by negative selection from naive AhR(+/-) and AhR(-/-) mice and polarised to Tc1/Th1 or Tc17/Th17 phenotypes with appropriate cytokines. Cell differentiation was assessed as a function of mRNA and protein (ELISA and flow cytometry) expression for interferon (IFN)-γ and for key Th17 cytokines. In AhR(+/-) mice, Th17 cells displayed an exclusive IL-17 profile, which was markedly inhibited by a selective AhR antagonist to levels observed in AhR knockout mice. Addition of the natural AhR agonist 6-formylindolo[3,2-b]carbazole (FICZ) markedly enhanced Th17 cell activity in the heterozygotes. In contrast, Tc17 cells polarised into 3 distinct subsets: producing either IL-17 or IFN-γ alone, or both cytokines. Blocking AhR was also detrimental to Tc17 development, with reduced responses recorded in AhR(-/-) mice and antagonist-mediated reduction of IL-17 expression in the heterozygotes. However, Tc17 cells were largely refractory to exogenous FICZ, presumably because Tc17 cells express baseline AhR mRNA, but unlike Th17 cells, there is no marked up-regulation during polarisation. Thus, Th17 cell development is more dependent upon AhR activation than is Tc17 cell development, suggesting that endogenous AhR ligands play a much greater role in driving Th17 cell responses. PMID:25203682

  11. Luciferase mRNA Transfection of Antigen Presenting Cells Permits Sensitive Nonradioactive Measurement of Cellular and Humoral Cytotoxicity

    Directory of Open Access Journals (Sweden)

    Tana A. Omokoko

    2016-01-01

    Full Text Available Immunotherapy is rapidly evolving as an effective treatment option for many cancers. With the emerging fields of cancer vaccines and adoptive cell transfer therapies, there is an increasing demand for high-throughput in vitro cytotoxicity assays that efficiently analyze immune effector functions. The gold standard 51Cr-release assay is very accurate but has the major disadvantage of being radioactive. We reveal the development of a versatile and nonradioactive firefly luciferase in vitro transcribed (IVT RNA-based assay. Demonstrating high efficiency, consistency, and excellent target cell viability, our optimized luciferase IVT RNA is used to transfect dividing and nondividing primary antigen presenting cells. Together with the long-lasting expression and minimal background, the direct measurement of intracellular luciferase activity of living cells allows for the monitoring of killing kinetics and displays paramount sensitivity. The ability to cotransfect the IVT RNA of the luciferase reporter and the antigen of interest into the antigen presenting cells and its simple read-out procedure render the assay high-throughput in nature. Results generated were comparable to the 51Cr release and further confirmed the assay’s ability to measure antibody-dependent cell-mediated cytotoxicity and complement-dependent cytotoxicity. The assay’s combined simplicity, practicality, and efficiency tailor it for the analysis of antigen-specific cellular and humoral effector functions during the development of novel immunotherapies.

  12. A Model of Cytotoxic T Antitumor Activation Stimulated by Pulsed Dendritic Cells

    Science.gov (United States)

    Pennisi, Marzio; Pappalardo, Francesco; Chiacchio, Ferdinando; Motta, Santo

    2011-09-01

    We present a preliminary ODE model to sketch the immune response of cytotoxic T cells against cancer through the use of pulsed autologous dendritic cells. The model is partially based on data coming from experiments that are presently in progress in the wet lab of our collaborators, but it can be applied in principle to different tumors. To this end, we show the immune response of cytotoxic T cells stimulated by autologous dendritic cells for different cancers.

  13. Spontaneous cytotoxic T-Cell reactivity against indoleamine 2,3-dioxygenase-2

    DEFF Research Database (Denmark)

    Sørensen, Rikke Bæk; Køllgaard, Tania; Andersen, Rikke Sick;

    2011-01-01

    in mouse models of cancer in a nontoxic fashion. Here, we describe the immunogenicity of IDO2 by showing the presence of spontaneous cytotoxic T-cell reactivity against IDO2 in peripheral blood of both healthy donors and cancer patients. Furthermore, we show that these IDO2-specific T cells are...... cytotoxic effector cells that recognize and kill tumor cells. Our data suggest that IDO2 might be a useful target for anticancer immunotherapeutic strategies....

  14. Garcinielliptone FC: antiparasitic activity without cytotoxicity to mammalian cells.

    Science.gov (United States)

    Silva, Ana P; Silva, Marcos P; Oliveira, Cristiano G; Monteiro, Daniela C; Pinto, Pedro L; Mendonça, Ronaldo Z; Costa Júnior, Joaquim S; Freitas, Rivelilson M; de Moraes, Josué

    2015-06-01

    Garcinielliptone FC (GFC) is a natural prenylated benzophenone found in the seeds of Platonia insignis Mart. (Clusiaceae), a native Brazilian plant. It has been chemically characterized and it is known that GFC has several biological activities such as antioxidant and vasorelaxant properties. In this study, we report the in vitro effect of GFC against the blood fluke Schistosoma mansoni, the parasite responsible for schistosomiasis mansoni. The anti-S. mansoni activity and cytotoxicity toward mammalian cells were determined for the compound. GFC⩾6.25 μM showed antischistosomal activity and confocal laser scanning microscopy analysis demonstrated several morphological alterations on the tegument of worms, and a correlation between viability and tegumental damage was observed. In addition, at sub-lethal concentrations of GFC (⩽3.125 μM), the number of S. mansoni eggs was reduced. More importantly, GFC exhibited no activity toward mammalian cells and, therefore, there is an appreciable selectivity of this compound against the helminths. In conclusion, these findings indicate the potential of GFC as an antiparasitic agent. PMID:25553916

  15. Production of proinflammatory mediators by indoor air bacteria and fungal spores in mouse and human cell lines.

    OpenAIRE

    Huttunen, Kati; Hyvärinen, Anne; Nevalainen, Aino; Komulainen, Hannu; Hirvonen, Maija-Riitta

    2003-01-01

    We compared the inflammatory and cytotoxic responses caused by household mold and bacteria in human and mouse cell lines. We studied the fungi Aspergillus versicolor, Penicillium spinulosum, and Stachybotrys chartarum and the bacteria Bacillus cereus, Pseudomonas fluorescens, and Streptomyces californicus for their cytotoxicity and ability to stimulate the production of inflammatory mediators in mouse RAW264.7 and human 28SC macrophage cell lines and in the human A549 lung epithelial cell lin...

  16. Mitochondrial electron transport chain identified as a novel molecular target of SPIO nanoparticles mediated cancer-specific cytotoxicity.

    Science.gov (United States)

    He, Chengyong; Jiang, Shengwei; Jin, Haijing; Chen, Shuzhen; Lin, Gan; Yao, Huan; Wang, Xiaoyong; Mi, Peng; Ji, Zhiliang; Lin, Yuchun; Lin, Zhongning; Liu, Gang

    2016-03-01

    Superparamagnetic iron oxide nanoparticles (SPIONs) are highly cytotoxic and target cancer cells with high specificity; however, the mechanism by which SPIONs induce cancer cell-specific cytotoxicity remains unclear. Herein, the molecular mechanism of SPION-induced cancer cell-specific cytotoxicity to cancer cells is clarified through DNA microarray and bioinformatics analyses. SPIONs can interference with the mitochondrial electron transport chain (METC) in cancer cells, which further affects the production of ATP, mitochondrial membrane potential, and microdistribution of calcium, and induces cell apoptosis. Additionally, SPIONs induce the formation of reactive oxygen species in mitochondria; these reactive oxygen species trigger cancer-specific cytotoxicity due to the lower antioxidative capacity of cancer cells. Moreover, the DNA microarray and gene ontology analyses revealed that SPIONs elevate the expression of metallothioneins in both normal and cancer cells but decrease the expression of METC genes in cancer cells. Overall, these results suggest that SPIONs induce cancer cell death by targeting the METC, which is helpful for designing anti-cancer nanotheranostics and evaluating the safety of future nanomedicines. PMID:26773667

  17. Clostridium perfringens epsilon toxin is cytotoxic for human renal tubular epithelial cells.

    Science.gov (United States)

    Fernandez Miyakawa, Mariano E; Zabal, Osvaldo; Silberstein, Claudia

    2011-04-01

    Clostridium perfringens epsilon toxin (ETX) is responsible for a fatal enterotoxemia in different animal species, producing extensive renal damage, neurological disturbance and edema of lungs, heart and kidneys. However, there is no information about the susceptibility of humans to ETX. Here, we report that primary cultures of human renal tubular epithelial cells (HRTEC) exposed to ETX showed a marked swelling with subsequent large blebs surrounding most cells. The incubation of HRTEC with ETX produced a reduction of cell viability in a dose- and time-dependent manner. The CD(50) after 1-hour and 24-hour incubation were 3 µg/mL and 0.5 µg/mL, respectively. The pulse with ETX for 3 min was enough to produce a significant cytotoxic effect on HRTEC after 1-hour incubation. ETX binds to HRTEC forming a large complex of about 160 kDa similar to what was found in the Madin-Darby canine kidney (MDCK) cell line. The HRTEC could be a useful cell model to improve the understanding of the mechanisms involved on the cell damage mediated by ETX. PMID:20488848

  18. Differential activation of proliferation and cytotoxicity in human T-cell lymphotropic virus type I Tax-specific CD8 T cells by an altered peptide ligand.

    OpenAIRE

    Höllsberg, P; Weber, W E; Dangond, F; Batra, V; Sette, A.; Hafler, D A

    1995-01-01

    Human T-cell leukemia virus type I (HTLV-I) gives rise to a neurologic disease known as HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP). Although the pathogenesis of the disease is unknown, the presence of a remarkably high frequency of Tax-specific, cytotoxic CD8 T cells may suggest a role of these cells in the development of HAM/TSP. Antigen-mediated signaling in a CD8 T-cell clone specific for the Tax(11-19) peptide of HTLV-I was studied using analog peptides substitute...

  19. Antioxidant and cytotoxic effects of hexane extract ofMorinda pubescens leaves in human liver cancer cell line

    Institute of Scientific and Technical Information of China (English)

    Jaya Kumar D; Jaya Santhi R

    2012-01-01

    ABSTRACT Objective:To evaluate the antioxidant and cytotoxic effects of hexane extract ofMorinda pubescens leaves and to find the primary bioactive compound responsible for antioxidant and cytotoxic activities.Methods: The individual compounds were isolated using column chromatography and were characterized by spectroscopic techniques. The antioxidant activity was evaluated for all individual isolated compounds byDPPH method usingL-Ascorbic acid as standard and cytotoxicity was assessed for the extract and the hyoscyamine byMTT assay, caspase test andRT-PCR study.Results:The antioxidant activity of the isolated compounds and the extract increased as the concentration increased. One of the isolated compound hyoscyamine showed the high antioxidant activity. The extract and the hyoscyamine dose-dependently decreased the cell viability in HepG2 cells. Hyoscyamine induced caspase-3mediated apoptosis. Up regulation of p53 gene expression provides cue for apoptotic activity of hyoscyamine. Conclusions: The results indicate that hexane extract possessed potent antioxidant and cytotoxic activity and hyoscyamine is the principal bioactive compound in hexane extract.

  20. METHYLCELLULOSE CELL-CULTURE AS A NEW CYTOTOXICITY TEST SYSTEM FOR BIOMATERIALS

    NARCIS (Netherlands)

    VANLUYN, MJA; VANWACHEM, PB; NIEUWENHUIS, P; DAMINK, LO; TENHOOPEN, H; FEIJEN, J

    1991-01-01

    The cytotoxicity of biomaterials can be tested in vitro using various culture systems. Liquid culture systems may detect cytotoxicity of a material either by culture of cells with extracts or with the material itself. In the latter instance, renewing the medium will remove possible released cytotoxi

  1. Selective induction of apoptosis by the cytotoxic analog AN-207 in cells expressing recombinant receptor for luteinizing hormone-releasing hormone

    OpenAIRE

    Danila, Daniel C; Schally, Andrew V.; Nagy, Attila; Alexander, Joseph M

    1999-01-01

    The selectivity of ligands specific for certain cells can be used to preferentially target chemotherapeutic compounds to neoplastic cells. Human breast, ovarian, endometrial, and prostatic cancers express receptors that can mediate the delivery of targeted cytotoxic compounds to neoplastic cells. Recently, a potent derivative of 2-pyrrolinodoxorubicin (AN-201) conjugated to [d-Lys6] luteinizing hormone-releasing hormone (LH-RH) (AN-207), was demonstrated to be less toxic than the nonconjugate...

  2. Cytotoxic activity of interferon alpha induced dendritic cells as a biomarker of glioblastoma

    Science.gov (United States)

    Mishinov, S. V.; Stupak, V. V.; Tyrinova, T. V.; Leplina, O. Yu.; Ostanin, A. A.; Chernykh, E. R.

    2016-08-01

    Dendritic cells (DCs) are the most potent antigen presenting cells that can play direct role in anti-tumor immune response as killer cells. DC tumoricidal activity can be stimulated greatly by type I IFN (IFNα and IFNβ). In the present study, we examined cytostatic and cytotoxic activity of monocyte-derived IFNα-induced DCs generated from patients with brain glioma and evaluated the potential use of these parameters in diagnostics of high-grade gliomas. Herein, we demonstrated that patient DCs do not possess the ability to inhibit the growth of tumor HEp-2 cell line but low-grade and high-grade glioma patients do not differ significantly in DC cytostatic activity. However, glioma patient DCs are characterized by reduced cytotoxic activity against HEp-2 cells. The impairment of DC cytotoxic function is observed mainly in glioblastoma patients. The cytotoxic activity of DCs against HEp-2 cells below 9% is an informative marker for glioblastomas.

  3. Biosynthesis, characterization and cytotoxic effect of plant mediated silver nanoparticles using Morinda citrifolia root extract.

    Science.gov (United States)

    Suman, T Y; Radhika Rajasree, S R; Kanchana, A; Elizabeth, S Beena

    2013-06-01

    Silver has been used since time to control bodily infection, prevent food spoilage and heal wounds by preventing infection. The present study aims at an environmental friendly method of synthesizing silver nanoparticles, from the root of Morinda citrifolia; without involving chemical agents associated with environmental toxicity. The obtained nanoparticles were characterized by UV-vis absorption spectroscopy with an intense surface plasmon resonance band at 413 nm clearly reveals the formation of silver nanoparticles. Fourier transmission infra red spectroscopy (FTIR) showed nanopartilces were capped with plant compounds. Field emission-scanning electron microscopy (FE-SEM) and Transmission electron microscopy (TEM) showed that the spherical nature of the silver nanoparticles with a size of 30-55 nm. The X-ray diffraction spectrum XRD pattern clearly indicates that the silver nanoparticles formed in the present synthesis were crystalline in nature. In addition these biologically synthesized nanoparticles were also proved to exhibit excellent cytotoxic effect on HeLa cell. PMID:23434694

  4. Cytotoxicity of cuprous oxide nanoparticles to fish blood cells: hemolysis and internalization

    Energy Technology Data Exchange (ETDEWEB)

    Chen Liqiang, E-mail: chenlq@ynu.edu.cn; Kang Bin [Yunnan University, Asian International Rivers Center, Yunnan Key Laboratory of International Rivers and Trans-boundary Eco-security (China); Ling Jian [Yunnan University, College of Chemistry and Chemical Engineering (China)

    2013-03-15

    Cuprous oxide nanoparticles (Cu{sub 2}O NPs) possess unique physical and chemical properties which are employed in a broad variety of applications. However, little is known about the adverse effects of Cu{sub 2}O NPs on organisms. In the current study, in vitro cytotoxicity of Cu{sub 2}O NPs (ca. 60 nm in diameter) to the blood cells of freshwater fish Carassius auratus was evaluated. A concentration-dependent hemolytic activity of Cu{sub 2}O NPs to red blood cells (RBCs) and the phagocytosis of Cu{sub 2}O NPs by leukocytes were revealed. The results showed that dosages of Cu{sub 2}O NPs greater than 40 {mu}g/mL were toxic to blood cells, and could cause serious membrane damage to RBCs. The EC{sub 50} value of Cu{sub 2}O NPs as obtained from RBCs and whole blood exposure was 26 and 63 {mu}g/mL, respectively. The generation of reactive oxygen species and the direct interaction between Cu{sub 2}O NPs and the cell membrane were suggested as the possible mechanism for cytotoxicity, and the intrinsic hemolytic active of Cu{sub 2}O NPs was the main contributor to the toxicity rather than solubilized copper ions. The adsorption of plasma proteins on the surfaces of Cu{sub 2}O NPs led to their aggregation in whole blood, and aggregate formation can significantly alleviate the hemolytic effect and subsequently mediate the phagocytosis of Cu{sub 2}O NPs by leukocytes.

  5. In vitro evaluation of the cytotoxicity and cellular uptake of CMCht/PAMAM dendrimer nanoparticles by glioblastoma cell models

    Energy Technology Data Exchange (ETDEWEB)

    Pojo, M., E-mail: martapojo@ecsaude.uminho.pt; Cerqueira, S. R.; Mota, T.; Xavier-Magalhaes, A.; Ribeiro-Samy, S. [University of Minho, Life and Health Sciences Research Institute (ICVS), School of Health Sciences (Portugal); Mano, J. F.; Oliveira, J. M., E-mail: miguel.oliveira@dep.uminho.pt; Reis, R. L. [ICVS/3Bs, PT Government Associated Laboratory (Portugal); Sousa, N.; Costa, B. M.; Salgado, A. J. [University of Minho, Life and Health Sciences Research Institute (ICVS), School of Health Sciences (Portugal)

    2013-05-15

    Glioblastoma (GBM) is simultaneously the most common and most malignant subtype tumor of the central nervous system. These are particularly dramatic diseases ranking first among all human tumor types for tumor-related average years of life lost and for which curative therapies are not available. Recently, the use of nanoparticles as drug delivery systems (DDS) for tumor treatment has gained particular interest. In an attempt to evaluate the potential of carboxymethylchitosan/poly(amidoamine) (CMCht/PAMAM) dendrimer nanoparticles as a DDS, we aimed to evaluate its cytotoxicity and internalization efficiency in GBM cell models. CMCht/PAMAM-mediated cytotoxicity was evaluated in a GBM cell line (U87MG) and in human immortalized astrocytes (hTERT/E6/E7) by MTS and double-stranded DNA quantification. CMCht/PAMAM internalization was assessed by double fluorescence staining. Both cells lines present similar internalization kinetics when exposed to a high dose (400 {mu}g/mL) of these nanoparticles. However, the internalization rate was higher in tumor GBM cells as compared to immortalized astrocytes when cells were exposed to lower doses (200 {mu}g/mL) of CMCht/PAMAM for short periods (<24 h). After 48 h of exposure, both cell lines present {approx}100% of internalization efficiency for the tested concentrations. Importantly, short-term exposures (1, 6, 12, 24, and 48 h) did not show cytotoxicity, and long-term exposures (7 days) to CMCht/PAMAM induced only low levels of cytotoxicity in both cell lines ({approx}20% of decrease in metabolic activity). The high efficiency and rate of internalization of CMCht/PAMAM we show here suggest that these nanoparticles may be an attractive DDS for brain tumor treatment in the future.

  6. In vitro evaluation of the cytotoxicity and cellular uptake of CMCht/PAMAM dendrimer nanoparticles by glioblastoma cell models

    International Nuclear Information System (INIS)

    Glioblastoma (GBM) is simultaneously the most common and most malignant subtype tumor of the central nervous system. These are particularly dramatic diseases ranking first among all human tumor types for tumor-related average years of life lost and for which curative therapies are not available. Recently, the use of nanoparticles as drug delivery systems (DDS) for tumor treatment has gained particular interest. In an attempt to evaluate the potential of carboxymethylchitosan/poly(amidoamine) (CMCht/PAMAM) dendrimer nanoparticles as a DDS, we aimed to evaluate its cytotoxicity and internalization efficiency in GBM cell models. CMCht/PAMAM-mediated cytotoxicity was evaluated in a GBM cell line (U87MG) and in human immortalized astrocytes (hTERT/E6/E7) by MTS and double-stranded DNA quantification. CMCht/PAMAM internalization was assessed by double fluorescence staining. Both cells lines present similar internalization kinetics when exposed to a high dose (400 μg/mL) of these nanoparticles. However, the internalization rate was higher in tumor GBM cells as compared to immortalized astrocytes when cells were exposed to lower doses (200 μg/mL) of CMCht/PAMAM for short periods (<24 h). After 48 h of exposure, both cell lines present ∼100% of internalization efficiency for the tested concentrations. Importantly, short-term exposures (1, 6, 12, 24, and 48 h) did not show cytotoxicity, and long-term exposures (7 days) to CMCht/PAMAM induced only low levels of cytotoxicity in both cell lines (∼20% of decrease in metabolic activity). The high efficiency and rate of internalization of CMCht/PAMAM we show here suggest that these nanoparticles may be an attractive DDS for brain tumor treatment in the future.

  7. Ascorbic acid enhances arsenic trioxide-induced cytotoxicity in multiple myeloma cells.

    Science.gov (United States)

    Grad, J M; Bahlis, N J; Reis, I; Oshiro, M M; Dalton, W S; Boise, L H

    2001-08-01

    Multiple myeloma (MM) is a clonal B-cell malignancy characterized by slow-growing plasma cells in the bone marrow (BM). Patients with MM typically respond to initial chemotherapies; however, essentially all progress to a chemoresistant state. Factors that contribute to the chemorefractory phenotype include modulation of free radical scavenging, increased expression of drug efflux pumps, and changes in gene expression that allow escape from apoptotic signaling. Recent data indicate that arsenic trioxide (As(2)O(3)) induces remission of refractory acute promyelocytic leukemia and apoptosis of cell lines overexpressing Bcl-2 family members; therefore, it was hypothesized that chemorefractory MM cells would be sensitive to As(2)O(3). As(2)O(3) induced apoptosis in 4 human MM cell lines: 8226/S, 8226/Dox40, U266, and U266/Bcl-x(L). The addition of interleukin-6 had no effect on cell death. Glutathione (GSH) has been implicated as an inhibitor of As(2)O(3)-induced cell death either through conjugating As(2)O(3) or by sequestering reactive oxygen induced by As(2)O(3). Consistent with this possibility, increasing GSH levels with N-acetylcysteine attenuated As(2)O(3) cytotoxicity. Decreases in GSH have been associated with ascorbic acid (AA) metabolism. Clinically relevant doses of AA decreased GSH levels and potentiated As(2)O(3)-mediated cell death of all 4 MM cell lines. Similar results were obtained in freshly isolated human MM cells. In contrast, normal BM cells displayed little sensitivity to As(2)O(3) alone or in combination with AA. Together, these data suggest that As(2)O(3) and AA may be effective antineoplastic agents in refractory MM and that AA might be a useful adjuvant in GSH-sensitive therapies. (Blood. 2001;98:805-813) PMID:11468182

  8. Autophagy inhibition facilitates erlotinib cytotoxicity in lung cancer cells through modulation of endoplasmic reticulum stress.

    Science.gov (United States)

    Wang, Zhongliang; Du, Tingting; Dong, Xiaorong; Li, Zhenyu; Wu, Gang; Zhang, Ruiguang

    2016-06-01

    Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) have revolutionized the treatment for non-small cell lung cancer patients, but acquired resistance limit the efficiency of this treatment. As a homeostatic cellular recycling mechanism, autophagy has been proposed to participate in the EGFR-TKI resistance. However, the role of autophagy in lung cancer treatment and the underlying mechanisms have not been clarified. In this study, we found the sensitivity to erlotinib, a well-used EGFR-TKI, was correlated with basal autophagy level. Erlotinib was able to induce autophagy not only in TKI-sensitive, but also TKI-resistant cancer cells. Inhibition of autophagy significantly enhanced cytotoxicity of erlotinib in TKI-resistant cancer cells via modulation of endoplasmic reticulum (ER) stress induced apoptosis. In this process, CCAAT/enhancer binding protein homologous protein (CHOP) acted as an executioner. Downregulation of CHOP with siRNA blocked the autophagy inhibition and erlotinib co-treatment induced apoptosis and prevented cancer cells from this co-treatment-induced cell death. Our findings suggest that autophagy inhibition overcomes erlotinib resistance through modulation of ER stress mediated apoptosis. PMID:27035631

  9. Evidence that 5-hydroxytryptamine/sub 3/ receptors mediate cytotoxic drug and radiation-evoked emesis

    Energy Technology Data Exchange (ETDEWEB)

    Miner, W.D.; Sanger, G.J.; Turner, D.H.

    1987-08-01

    The involvement of 5-hydroxytryptamine (5-HT) 5-HT/sub 3/ receptors in the mechanisms of severe emesis evoked by cytotoxic drugs or by total body irradiation have been studied in ferrets. Anti-emetic compounds tested were domperidone (a dopamine antagonist), metoclopramide (a gastric motility stimulant and dopamine antagonist at conventional doses, a 5-HT/sub 3/ receptor antagonist at higher doses) and BRL 24924 (a potent gastric motility stimulant and a 5-HT/sub 3/ receptor antagonist). Domperidone or metoclopramide prevented apomorphine-evoked emesis, whereas BRL 24924 did not. Similar doses of domperidone did not prevent emesis evoked by cis-platin or by total body irradiation, whereas metoclopramide or BRL 24924 greatly reduced or prevented these types of emesis. Metoclopramide and BRL 24924 also prevented emesis evoked by a combination of doxorubicin and cyclophosphamide. These results are discussed in terms of a fundamental role for 5-HT/sub 3/ receptors in the mechanisms mediating severely emetogenic cancer treatment therapies.

  10. Effects of Ginkgo biloba extract on cell proliferation and cytotoxicity in human hepatocellular carcinoma cells

    Institute of Scientific and Technical Information of China (English)

    Jane CJ Chao; Chia Chou Chu

    2004-01-01

    AIM: To study the effect of Ginkgo biloba extract (EGb 761)containing 22-27% fiavonoids (ginkgo-flavone glycosides)and 5-7% terpenoids (ginkgolides and bilobalides) on cell proliferation and cytotoxicity in human hepatocellular carcinoma (HCC) cells.METHODS: Human HCC cell lines (HepG2 and Hep3B) were incubated with various concentrations (0-1 000 mg/L) of EGb 761 solution. After 24 h incubation, cell proliferation and cytotoxicity were determined by 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay and lactate dehydrogenase (LDH)release, respectively. After 48 h incubation, the expression of proliferating cell nuclear antigen (PCNA) and p53 protein was measured by Western blotting.RESULTS: The results showed that EGb 761 (50-1 000 mg/L)significantly suppressed cell proliferation and increased LDH release (P<0.05) in HepG2 and Hep3B cells compared with the control group. The cell proliferation of HepG2 and Hep3B cells treated with EGb 761 (1 000 mg/L) was 45% and 39% of the control group (P<0.05), respectively. LDH release of HepG2 cells without and with EGb 761 (1 000 mg/L) treatment was 6.7% and 37.7%, respectively, and that of Hep3B cells without and with EGb 761 (1 000 mg/L) treatment was 7.2% and 40.3%, respectively. The expression of PCNA and p53 protein in HepG2 cells treated with EGb 761 (1 000 mg/L)was 85% and 174% of the control group, respectively.CONCLUSION: Ginkgobilobaextract significantly can suppress proliferation and increase cytotoxicity in HepG2 and Hep3B cells. Additionally, Ginkgo biloba extract can decrease PCNA and increase p53 expression in HepG2 cells.

  11. Δ8-Tetrahydrocannabinol induces cytotoxicity in macrophage J774-1 cells: Involvement of cannabinoid receptor 2 and p38 MAPK

    International Nuclear Information System (INIS)

    Tetrahydrocannabinol (THC), a psychoactive component of marijuana, is known to exert cytotoxicity in immune cells. In the present study, we examined the cytotoxicity of Δ8-THC in mouse macrophage J774-1 cells and a possible involvement of cannabinoid receptors and stress-responsive mitogen-activated protein kinases (MAPKs) in the cytotoxic process. J774-1 cells were treated with Δ8-THC (0–20 μM) for up to 6 h. As measured by the MTT and LDH assays, Δ8-THC induced cell death of J774-1 cells in a concentration- and/or exposure time-dependent manner. Δ8-THC-induced cell damage was associated with vacuole formation, cell swelling, chromatin condensation, and nuclear fragmentation. The cytotoxic effect of Δ8-THC was significantly prevented by a caspase-1 inhibitor Ac-YVAD-cmk but not a caspase-3 inhibitor z-DEVD-fmk. The pretreatment with SR144528, a CB2 receptor-selective antagonist, effectively suppressed Δ8-THC-induced cytotoxicity in J774-1 cells, which exclusively expressed CB2 receptors as indicated by real-time polymerase chain reaction analysis. In contrast, AM251, a CB1 receptor-selective antagonist, did not affect the cytotoxicity. Pertussis toxin and α-tocopherol significantly attenuated Δ8-THC-induced cytotoxicity suggesting that Gi/o protein coupling signal transduction and oxidative stress are responsible for the cytotoxicity. 8-THC stimulated the phosphorylation of p38 MAPK and c-Jun N-terminal kinase (JNK) in J774-1 cells, which were effectively antagonized by the pretreatment with SR144528. In addition, SB203580, a p38 MARK inhibitor, significantly attenuated the cytotoxic effect of Δ8-THC, whereas SP600125, a JNK inhibitor, significantly enhanced the cytotoxicity. These results suggest that the cytotoxicity of Δ8-THC to J774-1 cells is exerted mediated through the CB2 receptor followed by the activation of p38 MAPK

  12. Therapeutic potential of highly cytotoxic natural killer cells for gastric cancer.

    Science.gov (United States)

    Mimura, Kousaku; Kamiya, Takahiro; Shiraishi, Kensuke; Kua, Ley-Fang; Shabbir, Asim; So, Jimmy; Yong, Wei-Peng; Suzuki, Yoshiyuki; Yoshimoto, Yuya; Nakano, Takashi; Fujii, Hideki; Campana, Dario; Kono, Koji

    2014-09-15

    To develop more effective therapies for patients with advanced gastric cancer, we examined the potential of ex vivo expanded natural killer (NK) cells. We assessed the expression of ligands for NK Group 2 Member D (NKG2D, an important NK activation molecule) in primary tumors from 102 patients with gastric cancer by immunohistochemistry and determined their prognostic value. We then examined the in vitro and in vivo cytotoxicity of NK cells from healthy donors and patients with gastric cancer. The cytotoxicity of resting and of interleukin (IL)-2-activated NK cells was compared to that of NK cells expanded for 7 days by coculture with the K562-mb15-4.1BBL cell line. As a result, the expression of NKG2D ligands in primary tumors was correlated with favorable presenting features and outcomes, suggesting that gastric cancer may be sensitive to NK cell cytotoxicity. Although resting NK cells showed minimal cytotoxicity against gastric cancer cells, K562-mb15-4.1BBL-expanded NK cells were highly cytotoxic and significantly more powerful than IL-2-activated NK cells. Cytotoxicity was correlated with NKG2D ligand expression and could be modulated by mitogen-activated protein kinase and AKT-PI3 kinase inhibitors. The cytotoxicity of expanded NK cells against HER2-positive gastric cancer cells could be increased by Herceptin and further augmented by Lapatinib. Finally, expanded NK cells exhibited strong antitumor activity in immunodeficient mice engrafted with a gastric cancer cell line. In conclusion, gastric cancer tumors express NKG2D ligands and are highly susceptible to killing by NK cells stimulated by K562-mb15-4.1BBL. These results provide a strong rationale for clinical testing of these NK cells in patients and suggest their use to augment the effects of antibody therapy. PMID:24615495

  13. Effects of glutathione depletion using buthionine sulphoximine on the cytotoxicity in mammalian cells and human tumor cells in vitro

    International Nuclear Information System (INIS)

    An inhibitor of glutathione biosynthesis, buthionine sulphoximine (BSO), was used to deplete the endogenous thiols in mammalian cells in vitro. In this study, the cytotoxicity of BSO and BSO combined with the hypoxic cell radiosensitizer misonidazole (MISO) was investigated. Both aerobic and hypoxic cytotoxicity of MISO was found to be increased. The concentration of BSO required to reduce the colony forming ability to 50% (Cc) for the chronic cytotoxicity on V79 cells was 0.03 mmol/L under aerobic condition, while the Cc for the acute cytotoxicity on V79 cells under hypoxic and aerobic conditions was 0.4 and 0.5 mmol/L. The growth inhibition rate of human tumor cells K562 and SGC-7901 by BSO wa 6.89-26.06% and 12.01-55.69%, respectively. Enhanced cytotoxic activity was observed when BSO was used in combination with cis-dichlorodiamino Pt(II) or 5-fluorouracil

  14. Comparison of mammalian and fish cell line cytotoxicity: impact of endpoint and exposure duration

    International Nuclear Information System (INIS)

    Comparisons of acute toxic concentrations of chemicals to fish in vivo and cytotoxic concentrations to fish cell lines in vitro reveal rather good correlations of the toxic potencies in vitro and in vivo, but a clearly lower sensitivity of the fish cells. To examine whether the low sensitivity is specific for fish cells, cytotoxic potencies of reference chemicals from the Multicenter Evaluation of In Vitro Cytotoxicity program (MEIC) reported for the fish cell lines R1 and RTG-2 were compared with those obtained with the mouse Balb/c 3T3 cell line. Cytotoxic potencies (EC50 values) for MEIC reference chemicals were determined with exponentially growing Balb/c 3T3 cells using three different test protocols. To assess both endpoints, cell proliferation and cell survival, EC50 values were measured for the decrease in final cell protein after 24 and 72 h of exposure and for the reduction of cell protein increase during 24 h of exposure. EC50 values obtained with the fish cell lines R1 and RTG-2 using cell survival as endpoint were taken from the MEIC data base. The comparison of cytotoxic potencies shows that, in general, the fish cell lines and the mammalian cell line are almost equally sensitive towards the cytotoxic action of chemicals. The mammalian cell line assay, however, becomes considerably more sensitive, by factors of 3.4-8.5, than the fish cell line assays, if cell growth instead of cell survival is used as endpoint. It is concluded, that cell proliferation might be a better endpoint than cell survival and that mammalian cell lines might be suited to assess fish acute toxicity

  15. 5-Hydroxy-7-azaindolin-2-one, a novel hybrid of pyridinol and sunitinib: design, synthesis and cytotoxicity against cancer cells.

    Science.gov (United States)

    Shah, Sajita; Lee, Chaemin; Choi, Hyukjae; Gautam, Jaya; Jang, Hyeonjin; Kim, Geum Jin; Lee, Yu-Jeong; Chaudhary, Chhabi Lal; Park, Sang Won; Nam, Tae-Gyu; Kim, Jung-Ae; Jeong, Byeong-Seon

    2016-06-01

    Angiogenesis plays important roles in tumor growth and metastasis. Sunitinib (Sutent®) is an antitumor agent targeting receptor tyrosine kinases which are involved in angiogenesis as well as cancer cell growth and survival. Using the pyridin-3-ol scaffold, which was previously reported as an excellent antioxidant and antiangiogenic platform, we have synthesized sunitinib mimics 6 by hybridizing bicyclic pyridinol 4 as a key scaffold and pyrrole-2-carbaldehydes 7 as side chains. Cytotoxicity assays showed that compounds 6 have comparable to better anticancer activity than sunitinib against five different cancer cell lines. In addition, compounds 6 showed even lower levels of cytotoxicity against normal cells, resulting in up to 26-fold better safety windows, than sunitinib. Signaling pathway-associated transcription factor reporter assay and western blot analyses revealed that apoptosis induction in MDA-MB-231 human breast cancer cells by 6F is mainly mediated through the p53 increase and down-regulation of phospho-signal transducer and activator of transcription 3 (STAT3) and its target gene products, cyclin D, Bcl-2, and survivin. The data strongly suggest that our hybrid compounds can provide a novel anticancer scaffold with improved and safer cytotoxicity profiles than sunitinib. PMID:27145715

  16. Cytotoxic T-cells from T-cell receptor transgenic NOD8.3 mice destroy beta-cells via the perforin and Fas pathways.

    Science.gov (United States)

    Dudek, Nadine L; Thomas, Helen E; Mariana, Lina; Sutherland, Robyn M; Allison, Janette; Estella, Eugene; Angstetra, Eveline; Trapani, Joseph A; Santamaria, Pere; Lew, Andrew M; Kay, Thomas W H

    2006-09-01

    Cytotoxic T-cells are the major mediators of beta-cell destruction in type 1 diabetes, but the molecular mechanisms are not definitively established. We have examined the contribution of perforin and Fas ligand to beta-cell destruction using islet-specific CD8(+) T-cells from T-cell receptor transgenic NOD8.3 mice. NOD8.3 T-cells killed Fas-deficient islets in vitro and in vivo. Perforin-deficient NOD8.3 T-cells were able to destroy wild-type but not Fas-deficient islets in vitro. These results imply that NOD8.3 T-cells use both pathways and that Fas is required for beta-cell killing only when perforin is missing. Consistent with this theory, transgenic NOD8.3 mice with beta-cells that do not respond to Fas ligation were not protected from diabetes. We next investigated the mechanism of protection provided by overexpression of suppressor of cytokine signaling-1 (SOCS-1) in beta-cells of NOD8.3 mice. SOCS-1 islets remained intact when grafted into NOD8.3 mice and were less efficiently killed in vitro. However, addition of exogenous peptide rendered SOCS-1 islets susceptible to 8.3 T-cell-mediated lysis. Therefore, NOD8.3 T-cells use both perforin and Fas pathways to kill beta-cells and the surprising blockade of NOD8.3 T-cell-mediated beta-cell death by SOCS-1 overexpression may be due in part to reduced target cell recognition. PMID:16936188

  17. Adjuvant antiproliferative and cytotoxic effect of aloin in irradiated HeLaS3 cells

    Science.gov (United States)

    Nićiforović, A.; Adžić, M.; Zarić, B.; Radojčić, M. B.

    2007-09-01

    Naturally occurring phytoanthracycline, aloin, was used to radiosensitize HeLaS3 human cervix carcinoma cells. The results indicated that the cytotoxic adjuvant effect of aloin was synergistic with gammaionizing radiation at all drug concentrations and comparable to the cytotoxicity of 5-10 Gy ionizing radiation alone. Radiosensitization of HeLaS3 cells was achieved by 60 μM aloin, which reduced the IC50 dose of ionizing radiation from 3.4 to 2 Gy. Ionizing radiation and aloin alone or in combination are shown to cause perturbation of the HeLaS3 cell-cycle and increase the percentage of cells in the DNA synthesis (S) phase of the cell cycle. While either of the agents applied alone causes programmed cell death by apoptosis, the simultaneous cell damage by both agents through the altered redox balance compromised cell capacity to conduct this program and led to synergic cytotoxic cell death by necrosis.

  18. P-Glycoprotein-Mediated Efflux and Drug Sequestration in Lysosomes Confer Advantages of K562 Multidrug Resistance Sublines to Survive Prolonged Exposure to Cytotoxic Agents

    Directory of Open Access Journals (Sweden)

    Nathupakorn Dechsupa

    2009-01-01

    Full Text Available Problem statement: Cellular drug resistance to anticancer agents is major obstacle in cancer chemotherapy and the mechanisms by which these MDR cells possess for protecting themselves to survive prolonged exposure to cytotoxic agents still debating. The study aimed to clarify the role of P-glycoprotein (Pgp and enhanced drug sequestration in lysosomes to confer the multidrug resistance K562 cells with varied degree of Pgp expression. Approach: Erythromyelogenous leukemic K562 and its corresponding Pgp-over expression K562/adr (RF = 26.5 and K562/10000 (RF = 39.6 cells were used. The transport of intrinsic fluorescence molecules including acridine orange and pirarubicin across plasma membrane of living cells was performed by using spectrofluorometric and flow cytometric analysis. Results: Pirarubicin passively diffused through the plasma membrane of K562, K562/adr and K562/10000 cells with the same values of k+ = 3.4±0.3 pL. s-1.cell-1. Similar results were found for acridine orange, which passively diffused through plasma membrane of these cell lines about 30-fold faster than pirarubicin. The mean rate of Pgp-mediated efflux coefficient (ka of pirarubicin was equal to 2.6 ± 0.9 pL.s-1.cell-1 for K562/adr and 4.7 ± 1.0 pL.s-1.cell-1 for K562/10000 cells. The Pgp-mediated efflux of acridine orange could not be determined for K562/adr cells while an enhancement of exocytosis in K562/10000 cells was characterized. The acridine orange exhibited antiproliferative activity and IC50 for K562, K562/adr and K562/10000 cells was 447±40, 715±19 and 1,719±258 nM, respectively. Cytotoxicity of acridine orange was increased by 2-fold in the presence of and 25 nM monensin. Conclusion: The results clearly demonstrated for the first time that by using the same methods and cell lines. The predominant cellular defense mechanism determined in multidrug resistant cells depends upon the nature of molecular probes used. As molecular probe, pirarubicin clearly

  19. Rapid assay system for cytotoxicity tests using 14C-leucine incorporation into tumor cells

    International Nuclear Information System (INIS)

    Cell viability under various conditions of cytotoxicity test was assessed by terminal labeling of tumor cells, T24 cell line derived from urinary bladder carcinoma, with 14C-leucine. Changes of 14C-leucine incorporation into the cells were fairly proportional to those of viable cell number measured by the trypan blue exclusion method, but a definite correlation between the two measurements was not always found following cytotoxic manipulations. When the cells were labeled immediately after drug treatments, 14C-leucine incorporation usually led to fluctuated and insensitive results presumably due to disturbed metabolic activities unrelated to cell viability and failed to indicate the degree of cell damage. It was shown, however, that the cytotoxicity test was satisfactorily determined by labeling tumor cells with 14C-leucine after recovery in fresh medium for 24 hr. Cytotoxic effects of anticancer drugs with concentration- and time-dependency, hyperthermia and phytohemagglutinin-stimulated lymphocytes were demonstrated by the radioactivity incorporated into the target cells on day 2 after removal of the cytotoxic factors. The results indicate that the terminal labeling of tumor cells with 14C-leucine can be used as a rapid and reliable measure sensitivities to cell viability for an in vitro assay system. (author)

  20. Chemical Characterization and in Vitro Cytotoxicity on Squamous Cell Carcinoma Cells of Carica Papaya Leaf Extracts

    OpenAIRE

    Thao T. Nguyen; Marie-Odile Parat; Mark P. Hodson; Jenny Pan; Paul N. Shaw; Hewavitharana, Amitha K.

    2015-01-01

    In traditional medicine, Carica papaya leaf has been used for a wide range of therapeutic applications including skin diseases and cancer. In this study, we investigated the in vitro cytotoxicity of aqueous and ethanolic extracts of Carica papaya leaves on the human oral squamous cell carcinoma SCC25 cell line in parallel with non-cancerous human keratinocyte HaCaT cells. Two out of four extracts showed a significantly selective effect towards the cancer cells and were found to contain high l...

  1. Erythropoietin protects myocardin-expressing cardiac stem cells against cytotoxicity of tumor necrosis factor-{alpha}

    Energy Technology Data Exchange (ETDEWEB)

    Madonna, Rosalinda [The Center for Cardiovascular Biology and Atherosclerosis Research, The University of Texas Health Science Center at Houston, Texas (United States); Institute of Cardiology, and Center of Excellence on Aging, ' G. d' Annunzio' University, Chieti (Italy); Shelat, Harnath; Xue, Qun; Willerson, James T. [The Center for Cardiovascular Biology and Atherosclerosis Research, The University of Texas Health Science Center at Houston, Texas (United States); The Texas Heart Institute at St. Luke' s Episcopal Hospital, Houston, Texas (United States); De Caterina, Raffaele [Institute of Cardiology, and Center of Excellence on Aging, ' G. d' Annunzio' University, Chieti (Italy); Geng, Yong-Jian, E-mail: yong-jian.geng@uth.tmc.edu [The Center for Cardiovascular Biology and Atherosclerosis Research, The University of Texas Health Science Center at Houston, Texas (United States); The Texas Heart Institute at St. Luke' s Episcopal Hospital, Houston, Texas (United States)

    2009-10-15

    Cardiac stem cells are vulnerable to inflammation caused by infarction or ischemic injury. The growth factor, erythropoietin (Epo), ameliorates the inflammatory response of the myocardium to ischemic injury. This study was designed to assess the role of Epo in regulation of expression and activation of the cell death-associated intracellular signaling components in cardiac myoblasts stimulated with the proinflammatory cytokine tumor necrosis factor (TNF)-{alpha}. Cardiac myoblasts isolated from canine embryonic hearts characterized by expression of myocardin A, a promyogenic transcription factor for cardiovascular muscle development were pretreated with Epo and then exposed to TNF-{alpha}. Compared to untreated cells, the Epo-treated cardiac myoblasts exhibited better morphology and viability. Immunoblotting revealed lower levels of active caspase-3 and reductions in iNOS expression and NO production in Epo-treated cells. Furthermore, Epo pretreatment reduced nuclear translocation of NF-{kappa}B and inhibited phosphorylation of inhibitor of kappa B (I{kappa}B) in TNF-{alpha}-stimulated cardiac myoblasts. Thus, Epo protects cardiac myocyte progenitors or myoblasts against the cytotoxic effects of TNF-{alpha} by inhibiting NF-{kappa}B-mediated iNOS expression and NO production and by preventing caspase-3 activation.

  2. In vitro cytotoxicity of Indonesian stingless bee products against human cancer cell lines

    Directory of Open Access Journals (Sweden)

    Paula M. Kustiawan

    2014-07-01

    Conclusions: Propolis from T. incisa and Trigona fusco-balteata contain an in vitro cytotoxic activity against human cancer cell lines. Further study is required, including the isolation and characterization of the active antiproliferative agent(s.

  3. Cytotoxic effects of four aescin types on human colon adenocarcinoma cell lines.

    Science.gov (United States)

    Seweryn, Ewa; Gleńsk, Michal; Sroda-Pomianek, Kamila; Ceremuga, Ireneusz; Wlodarczyk, Maciej; Gamian, Andrzej

    2014-03-01

    Four types of aescin that are available on the pharmaceutical market, beta-aescin crystalline, beta-aescin amorphous, beta-aescin sodium and aescin polysulfate, have been analyzed for their cytotoxic effects on human colon adenocarcinoma (LoVo) and doxorubicin-resistant human colon adenocarcinoma cell lines (LoVo/Dx). Their cytotoxic activities were evaluated by sulforhodamine B (SRB) and methyl tetrazolium (MTT) assays. All four types of aescin exerted strong dose-dependent cytotoxicity to LoVo and, to a lesser degree, LoVo/Dx cell lines. The IC50 value for the LoVo/Dx cell line was higher, but still dose-dependent. Results from both assays demonstrated that p-aescin crystalline has the most cytotoxic activity toward human colon adenocarcinoma cell lines. PMID:24689224

  4. Novel Mutation in Syntaxin-Binding Protein 2 (STXBP2) Prevents IL-2-induced Natural Killer Cell Cytotoxicity

    OpenAIRE

    Saltzman, Rushani W.; Monaco-Shawver, Linda; Zhang, Kejian; Sullivan, Kathleen E.; Filipovich, Alexandra H.; Orange, Jordan S.

    2012-01-01

    We have identified dizygotic twins with a novel syntaxin-binding protein 2 (STXBP2) mutation, where cytotoxicity cannot be restored with IL-2. This defines STXBP2 as an absolute requirement for NK cell cytotoxic function.

  5. Electrochemical monitoring of phytochelatin accumulation in Nicotiana tabacum cells exposed to sub-cytotoxic and cytotoxic levels of cadmium

    Energy Technology Data Exchange (ETDEWEB)

    Fojta, Miroslav [Laboratory of Biophysical Chemistry and Molecular Oncology, Institute of Biophysics, Academy of Sciences of the Czech Republic, Kralovopolska 135, 612 65 Brno (Czech Republic)]. E-mail: fojta@ibp.cz; Fojtova, Miloslava [Laboratory of Molecular Epigenetics, Institute of Biophysics, Academy of Sciences of the Czech Republic, Kralovopolska 135, 612 65 Brno (Czech Republic); Havran, Ludek [Laboratory of Biophysical Chemistry and Molecular Oncology, Institute of Biophysics, Academy of Sciences of the Czech Republic, Kralovopolska 135, 612 65 Brno (Czech Republic); Pivonkova, Hana [Laboratory of Biophysical Chemistry and Molecular Oncology, Institute of Biophysics, Academy of Sciences of the Czech Republic, Kralovopolska 135, 612 65 Brno (Czech Republic); Dorcak, Vlastimil [Laboratory of Biophysical Chemistry and Molecular Oncology, Institute of Biophysics, Academy of Sciences of the Czech Republic, Kralovopolska 135, 612 65 Brno (Czech Republic); Sestakova, Ivana [J. Heyrovsky Institute of Physical Chemistry, Academy of Sciences of the Czech Republic, Dolejskova 3, 182 23 Prague 8 (Czech Republic)

    2006-02-03

    Cadmium belongs to the most dangerous environmental pollutants among the toxic heavy metals seriously affecting vital functions in both animal and plant cells. It has been previously shown that cadmium ions at 50-100 {mu}M concentrations caused tobacco BY-2 (TBY-2) cells to enter apoptosis within several days of exposure. Phytochelatins (PCs), the 'plant metallothioneins', are cysteine-rich peptides involved in detoxification of heavy metals in plants. The PCs are synthesized in response to the heavy metal exposure. In this paper, we utilized electrochemical analysis to monitor accumulation of PCs in the TBY-2 cells exposed to cadmium ions. Measurements of a characteristic PC signal at mercury electrode in the presence of cobalt ions made it possible to detect changes in the cellular PC levels during the time of cultivation, starting from 30 min after exposure. Upon TBY-2 cultivation in the presence of cytotoxic cadmium concentrations, the PC levels remarkably increased during the pre-apoptotic phase and reached a limiting value at cultivation times coinciding with apoptosis trigger. The PC level observed for a sub-cytotoxic cadmium concentration (10 {mu}M) was about three-times lower than that observed for the 50 or 100 {mu}M cadmium ions after 5 days of exposure. We show that using a simple electrochemical analysis, synthesis of PCs in plant cells can be easily followed in parallel with other tests of the cellular response to the toxic heavy metal stress.

  6. CYTOTOXICITY AND MODE OF CELL DEATH INDUCED BY TRIPHENYLTIN (IV COMPOUNDS IN VITRO

    Directory of Open Access Journals (Sweden)

    Normah Awang

    2014-01-01

    Full Text Available A series of newly synthesized organotin (IV with N-alkyl-N-phenyldithiocarbamate ligands namely triphenyltin (IV ethylphenyldithiocarbamate (compound 1 and triphenyltin (IV butylphenyldithiocarbamate (compound 2 were assessed for their cytotoxic effect against HT-29 human colon adenocarcinoma cells and human CCD-18Co normal colon cells. The cytotoxicity of these organotins in both cells was assessed using 3-(4,5-dimethylthiazol-2-yl-2, 5-diphenyltetrazholium bromide (MTT assay upon 24 h treatment. Both compounds demonstrated potent cytotoxicity towards HT-29 cells with the IC50 of 0.18 µM for compound 1 and 0.20 µM for compound 2. Interestingly, compound 1 exhibited lower cytotoxicity towards CCD-18Co with IC50 of 1.55 µM whereas no IC50 was detected for compound 2 up to 2 µM treatment. The mode of cell death was determined based on the externalization of phosphatidylserine using flow cytometry. Cells treated with compound 1 and compound 2 were mainly viable and the apoptotic cell death was around 10% which suggests that both compounds induced growth arrest. In conclusion, this study demonstrated that both compounds were selective towards human colorectal cells by giving a strong cytotoxicity to cancer cells and low toxicity towards normal cells. Both compounds were suggested to induce growth arrest in HT-29 cells.

  7. Inhibition of sulfur mustard-induced cytotoxicity and inflammation by the macrolide antibiotic roxithromycin in human respiratory epithelial cells

    Directory of Open Access Journals (Sweden)

    Barker Peter E

    2007-05-01

    Full Text Available Abstract Background Sulfur mustard (SM is a potent chemical vesicant warfare agent that remains a significant military and civilian threat. Inhalation of SM gas causes airway inflammation and injury. In recent years, there has been increasing evidence of the effectiveness of macrolide antibiotics in treating chronic airway inflammatory diseases. In this study, the anti-cytotoxic and anti-inflammatory effects of a representative macrolide antibiotic, roxithromycin, were tested in vitro using SM-exposed normal human small airway epithelial (SAE cells and bronchial/tracheal epithelial (BTE cells. Cell viability, expression of proinflammatory cytokines including interleukin (IL-1β, IL-6, IL-8 and tumor necrosis factor (TNF, and expression of inducible nitric oxide synthase (iNOS were examined, since these proinflammatory cytokines/mediators are import indicators of tissue inflammatory responses. We suggest that the influence of roxithromycin on SM-induced inflammatory reaction could play an important therapeutic role in the cytotoxicity exerted by this toxicant. Results MTS assay and Calcein AM/ethidium homodimer (EthD-1 fluorescence staining showed that roxithromycin decreased SM cytotoxicity in both SAE and BTE cells. Also, roxithromycin inhibited the SM-stimulated overproduction of the proinflammatory cytokines IL-1β, IL-6, IL-8 and TNF at both the protein level and the mRNA level, as measured by either enzyme-linked immunosorbent assay (ELISA or real-time RT-PCR. In addition, roxithromycin inhibited the SM-induced overexpression of iNOS, as revealed by immunocytochemical analysis using quantum dots as the fluorophore. Conclusion The present study demonstrates that roxithromycin has inhibitory effects on the cytotoxicity and inflammation provoked by SM in human respiratory epithelial cells. The decreased cytotoxicity in roxithromycin-treated cells likely depends on the ability of the macrolide to down-regulate the production of proinflammatory

  8. Role of reactive oxygen species in cis-dichlorodiammineplatinum-induced cytotoxicity on bladder cancer cells.

    OpenAIRE

    Miyajima, A; Nakashima, J.; Yoshioka, K; Tachibana, M.; Tazaki, H.; Murai, M

    1997-01-01

    This study was undertaken to investigate the intracellular induction of reactive oxygen species (ROS) by cis-dichlorodiammineplatinum (CDDP) and the augmentation of their cytotoxicity in bladder cancer cells (KU7) by enhancement of ROS generation by the glutathione (GSH) depletors buthionine sulphoximine (BSO) and diethylmaleate (DEM). CDDP-induced cytotoxicity in KU7 cells and its modulation by GSH depletors were determined using spectrophotometric measurement with crystal violet staining. T...

  9. Immunohistochemical localization of granzyme B antigen in cytotoxic cells in human tissues.

    OpenAIRE

    Hameed, A.; Truong, L D; Price, V; Kruhenbuhl, O.; Tschopp, J

    1991-01-01

    Human granzyme B antigen is expressed in cytoplasmic granules of activated cytotoxic T lymphocytes and natural killer cells. Recombinant granzyme B was generated using a prokaryotic expression vector under the control of T7 transcription and translation signals. The 25-kd recombinant protein (granzyme B) was used to develop a rabbit polyclonal antiserum. Purified anti-granzyme B antibodies were used to detect the antigen expression in cytotoxic cells in human tissues. Using the avidin-biotin-...

  10. Modulating microtubule stability enhances the cytotoxic response of cancer cells to paclitaxel

    OpenAIRE

    Ahmed, Ahmed Ashour; Wang, Xiaoyan; Lu, Zhen; Goldsmith, Juliet,; Le, Xiao-Feng; Grandjean, Geoffrey; Bartholomeusz, Geoffrey; Broom, Bradley; Bast, Robert C.

    2011-01-01

    The extracellular matrix protein TGFBI enhances the cytotoxic response of cancer cells to paclitaxel by affecting integrin signals that stabilize microtubules. Extending the implications of this knowledge, we tested the more general hypothesis that cancer cell signals which increase microtubule stability before exposure to paclitaxel may increase its ability to stablize microtubules and thereby enhance its cytotoxicity. Toward this end, we performed an siRNA screen to evaluate how genetic dep...

  11. Environmentally persistent free radicals amplify ultrafine particle mediated cellular oxidative stress and cytotoxicity

    Directory of Open Access Journals (Sweden)

    Balakrishna Shrilatha

    2009-04-01

    Full Text Available Abstract Background Combustion generated particulate matter is deposited in the respiratory tract and pose a hazard to the lungs through their potential to cause oxidative stress and inflammation. We have previously shown that combustion of fuels and chlorinated hydrocarbons produce semiquinone-type radicals that are stabilized on particle surfaces (i.e. environmentally persistent free radicals; EPFRs. Because the composition and properties of actual combustion-generated particles are complex, heterogeneous in origin, and vary from day-to-day, we have chosen to use surrogate particle systems. In particular, we have chosen to use the radical of 2-monochlorophenol (MCP230 as the EPFR because we have previously shown that it forms a EPFR on Cu(IIO surfaces and catalyzes formation of PCDD/F. To understand the physicochemical properties responsible for the adverse pulmonary effects of combustion by-products, we have exposed human bronchial epithelial cells (BEAS-2B to MCP230 or the CuO/silica substrate. Our general hypothesis was that the EPFR-containing particle would have greater toxicity than the substrate species. Results Exposure of BEAS-2B cells to our combustion generated particle systems significantly increased reactive oxygen species (ROS generation and decreased cellular antioxidants resulting in cell death. Resveratrol treatment reversed the decline in cellular glutathione (GSH, glutathione peroxidase (GPx, and superoxide dismutase (SOD levels for both types of combustion-generated particle systems. Conclusion The enhanced cytotoxicity upon exposure to MCP230 correlated with its ability to generate more cellular oxidative stress and concurrently reduce the antioxidant defenses of the epithelial cells (i.e. reduced GSH, SOD activity, and GPx. The EPFRs in MCP230 also seem to be of greater biological concern due to their ability to induce lipid peroxidation. These results are consistent with the oxidizing nature of the CuO/silica ultrafine

  12. Rhinovirus infection induces cytotoxicity and delays wound healing in bronchial epithelial cells

    Directory of Open Access Journals (Sweden)

    Constantopoulos Andreas G

    2005-10-01

    Full Text Available Abstract Background Human rhinoviruses (RV, the most common triggers of acute asthma exacerbations, are considered not cytotoxic to the bronchial epithelium. Recent observations, however, have questioned this knowledge. The aim of this study was to evaluate the ability of RV to induce epithelial cytotoxicity and affect epithelial repair in-vitro. Methods Monolayers of BEAS-2B bronchial epithelial cells, seeded at different densities were exposed to RV serotypes 1b, 5, 7, 9, 14, 16. Cytotoxicity was assessed chromatometrically. Epithelial monolayers were mechanically wounded, exposed or not to RV and the repopulation of the damaged area was assessed by image analysis. Finally epithelial cell proliferation was assessed by quantitation of proliferating cell nuclear antigen (PCNA by flow cytometry. Results RV1b, RV5, RV7, RV14 and RV16 were able to induce considerable epithelial cytotoxicity, more pronounced in less dense cultures, in a cell-density and dose-dependent manner. RV9 was not cytotoxic. Furthermore, RV infection diminished the self-repair capacity of bronchial epithelial cells and reduced cell proliferation. Conclusion RV-induced epithelial cytotoxicity may become considerable in already compromised epithelium, such as in the case of asthma. The RV-induced impairment on epithelial proliferation and self-repair capacity may contribute to the development of airway remodeling.

  13. Antioxidant studies of chitosan nanoparticles containing naringenin and their cytotoxicity effects in lung cancer cells.

    Science.gov (United States)

    Kumar, Sekar Praveen; Birundha, Kannan; Kaveri, Kannan; Devi, K T Ramya

    2015-01-01

    Chitosan based nano carrier systems have been widely explored owing to its reliability and simpler synthesis route. In the current study, chitosan (CS) encapsulated naringenin (NAR) nanoparticles (CS-NPs/NAR) were synthesized by ionic gelation method mediated by tripolyphosphate (TPP) as a cross-linker and characterized by DLS, SEM, Zeta potential, FT-IR and EDS analyses. The encapsulation efficiency of CS-NPs/NAR was determined by Folin-Ciocalteau (FC) and high performance liquid chromatography (HPLC) techniques. The native CS-NPs were found to be sized at 53.2 nm, while an increase in the size to 407.47 nm was observed upon loading with NAR. The encapsulation efficiency of CS-NPs/NAR was identified to be ∼70% by FC method and ∼80% by HPLC method, respectively. The release of NAR from CS-NPs/NAR in simulated gastric fluid was found to be ∼15% and remaining 85% of NAR was entrapped in CS-NPs/NAR. Furthermore, the free radical scavenging ability of CS-NPs/NAR was studied by Nitrate scavenging, 2, 2-diphenyl-2-picryl hydrazyl hydrate and hydroxyl radical scavenging assays. The free radical scavenging activity was significantly higher in CS-NPs/NAR. MTT based cytotoxic analysis also depicted the non-toxic nature of CS-NPs/NAR towards normal fibroblast 3T3 cells, while cytotoxic effects were noticed against A549 lung cancer cells. Hence, the current investigations showed the superiority of chitosan encapsulated NAR over free NAR and suggested an efficient system for delivering NAR with antioxidant and anticancer activities. PMID:25840152

  14. Astaxanthin Inhibits Acetaldehyde-Induced Cytotoxicity in SH-SY5Y Cells by Modulating Akt/CREB and p38MAPK/ERK Signaling Pathways

    OpenAIRE

    Tingting Yan; Yan Zhao; Xia Zhang; Xiaotong Lin

    2016-01-01

    Excessive alcohol consumption can lead to brain tissue damage and cognitive dysfunction. Acetaldehyde, the most toxic metabolite of ethanol, mediates the brain tissue damage and cognitive dysfunction induced by chronic excessive alcohol consumption. In this study, the effect of astaxanthin, a marine bioactive compound, on acetaldehyde-induced cytotoxicity was investigated in SH-SY5Y cells. It was found that astaxanthin protected cells from apoptosis by ameliorating the effect of acetaldehyde ...

  15. Impact of DNA repair pathways on the cytotoxicity of piperlongumine in chicken DT40 cell-lines.

    Science.gov (United States)

    Okamoto, Saki; Narita, Takeo; Sasanuma, Hiroyuki; Takeda, Shunichi; Masunaga, Shin-Ichiro; Bessho, Tadayoshi; Tano, Keizo

    2014-07-01

    Piperlongumine is a naturally-occurring small molecule with various biological activities. Recent studies demonstrate that piperlongumine selectively kills various types of transformed cells with minimal toxicity to non-transformed cells by inducing a high level of reactive oxygen species (ROS). ROS generates various types of DNA lesions, including base modifications and single strand breaks. In order to examine the contribution of ROS-induced DNA damage to the cytotoxicity by piperlongumine, various DNA repair-deficient chicken DT40 cell-lines with a single DNA repair gene deletion were tested for cellular sensitivity to piperlongumine. The results showed that cell lines defective in homologous recombination (HR) display hyper-sensitivity to piperlongumine, while other cell lines with a deficiency in non-homologous end joining (NHEJ), base excision repair (BER), nucleotide excision repair (NER), Fanconi anemia (FA) pathway, or translesion DNA synthesis (TLS) polymerases, show no sensitivity to piperlongumine. The results strongly implicate that double strand breaks (DSBs) generated by piperlongumine are major cytotoxic DNA lesions. Furthermore, a deletion of 53BP1 or Ku70 in the BRCA1-deficient cell line restored cellular resistance to piperlongumine. This strongly supports the idea that piperlongumine induces DSB- mediated cell death. Interestingly, piperlongumine makes the wild type DT40 cell line hypersensitive to a PARP-inhibitor, Olaparib. The results implicate that piperlongumine inhibits HR. Further analysis with cell-based HR assay and the kinetic study of Rad51 foci formation confirmed that piperlongumine suppresses HR activity. Altogether, we revealed novel mechanisms of piperlongumine-induced cytotoxicity. PMID:25221646

  16. In vitro cytotoxicity of silver nanoparticles and zinc oxide nanoparticles to human epithelial colorectal adenocarcinoma (Caco-2) cells

    Energy Technology Data Exchange (ETDEWEB)

    Song, Yijuan [Zhejiang Provincial Key Laboratory of Biometrology and Inspection and Quarantine, China Jiliang University, Hangzhou 310018 (China); Guan, Rongfa, E-mail: rongfaguan@163.com [Zhejiang Provincial Key Laboratory of Biometrology and Inspection and Quarantine, China Jiliang University, Hangzhou 310018 (China); Lyu, Fei [Department of Food Science and Technology, Zhejiang University of Technology, Hangzhou 310014 (China); Kang, Tianshu; Wu, Yihang [Zhejiang Provincial Key Laboratory of Biometrology and Inspection and Quarantine, China Jiliang University, Hangzhou 310018 (China); Chen, Xiaoqiang [Hubei University of Technology, Wuhan 430068 (China)

    2014-11-15

    Highlights: • The characterization of Ag NPs and ZnO NPs. • The various morphologies of Caco-2 cells stained with AO/EB. • The viability of Caco-2 cells after Ag NPs and ZnO NPs exposure. • The cytotoxicity of Ag NPs and ZnO NPs on Caco-2 cells by oxidative stress assays. - Abstract: With the increasing applications of silver nanoparticles (Ag NPs) and zinc oxide nanoparticles (ZnO NPs) in foods and cosmetics, the concerns about the potential toxicities to human have been raised. The aims of this study are to observe the cytotoxicity of Ag NPs and ZnO NPs to human epithelial colorectal adenocarcinoma (Caco-2) cells in vitro, and to discover the toxicity mechanism of nanoparticles on Caco-2 cells. Caco-2 cells were exposed to 10, 25, 50, 100, 200 μg/mL of Ag NPs and ZnO NPs (90 nm). AO/EB double staining was used to characterize the morphology of the treated cells. The cell counting kit-8 (CCK-8) assay was used to detect the proliferation of the cells. Reactive oxygen species (ROS), superoxide dismutase (SOD) and glutathione (GSH) assay were used to explore the oxidative damage of Caco-2 cells. The results showed that Ag NPs and ZnO NPs (0–200 μg/mL) had highly significant effect on the Caco-2 cells activity. ZnO NPs exerted higher cytotoxicity than Ag NPs in the same concentration range. ZnO NPs have dose-depended toxicity. The LD{sub 50} of ZnO NPs in Caco-2 cells is 0.431 mg/L. Significant depletion of SOD level, variation in GSH level and release of ROS in cells treated by ZnO NPs were observed, which suggests that cytotoxicity of ZnO NPs in intestine cells might be mediated through cellular oxidative stress. While Caco-2 cells treated with Ag NPs at all experimental concentrations showed no cellular oxidative damage. Moreover, the cells’ antioxidant capacity increased, and reached the highest level when the concentration of Ag NPs was 50 μg/mL. Therefore, it can be concluded that Ag NPs are safer antibacterial material in food packaging materials

  17. In vitro cytotoxicity of silver nanoparticles and zinc oxide nanoparticles to human epithelial colorectal adenocarcinoma (Caco-2) cells

    International Nuclear Information System (INIS)

    Highlights: • The characterization of Ag NPs and ZnO NPs. • The various morphologies of Caco-2 cells stained with AO/EB. • The viability of Caco-2 cells after Ag NPs and ZnO NPs exposure. • The cytotoxicity of Ag NPs and ZnO NPs on Caco-2 cells by oxidative stress assays. - Abstract: With the increasing applications of silver nanoparticles (Ag NPs) and zinc oxide nanoparticles (ZnO NPs) in foods and cosmetics, the concerns about the potential toxicities to human have been raised. The aims of this study are to observe the cytotoxicity of Ag NPs and ZnO NPs to human epithelial colorectal adenocarcinoma (Caco-2) cells in vitro, and to discover the toxicity mechanism of nanoparticles on Caco-2 cells. Caco-2 cells were exposed to 10, 25, 50, 100, 200 μg/mL of Ag NPs and ZnO NPs (90 nm). AO/EB double staining was used to characterize the morphology of the treated cells. The cell counting kit-8 (CCK-8) assay was used to detect the proliferation of the cells. Reactive oxygen species (ROS), superoxide dismutase (SOD) and glutathione (GSH) assay were used to explore the oxidative damage of Caco-2 cells. The results showed that Ag NPs and ZnO NPs (0–200 μg/mL) had highly significant effect on the Caco-2 cells activity. ZnO NPs exerted higher cytotoxicity than Ag NPs in the same concentration range. ZnO NPs have dose-depended toxicity. The LD50 of ZnO NPs in Caco-2 cells is 0.431 mg/L. Significant depletion of SOD level, variation in GSH level and release of ROS in cells treated by ZnO NPs were observed, which suggests that cytotoxicity of ZnO NPs in intestine cells might be mediated through cellular oxidative stress. While Caco-2 cells treated with Ag NPs at all experimental concentrations showed no cellular oxidative damage. Moreover, the cells’ antioxidant capacity increased, and reached the highest level when the concentration of Ag NPs was 50 μg/mL. Therefore, it can be concluded that Ag NPs are safer antibacterial material in food packaging materials than

  18. Reduced LAK cytotoxicity of peripheral blood mononuclear cells in patients with bladder cancer

    DEFF Research Database (Denmark)

    Hermann, G G; Petersen, K R; Steven, K; Zeuthen, J

    1990-01-01

    determined in healthy controls. The differences in the cytotoxicities were correlated with specific changes in the subsets of peripheral blood mononuclear cells (PBMC). PBMC from 37 patients and 13 healthy controls were tested against the bladder cancer cell line T24 in 51Cr-release assays. The PBMC subsets......The cytotoxicity of unstimulated peripheral blood mononuclear cells (US-PBMC), phytohemagglutinin (PHA)-stimulated PBMC (PS-PBMC) and interleukin-2 (IL-2)-activated PBMC (LAK cells) was assessed in patients with noninvasive and invasive transitional-cell bladder cancer and compared with those...... the reduced ability of bladder cancer patient PBMC to develop LAK-cell cytotoxicity is a result of a low incidence of CD56+ and CD57+ cells in the blood. These findings indicate that IL-2 therapy alone might not be a sufficient therapy of bladder cancer patients....

  19. Cytotoxicity of methanol extracts of Elaeis guineensis on MCF-7 and Vero cell lines

    Institute of Scientific and Technical Information of China (English)

    Soundararajan; Vijayarathna; Sreenivasan; Sasidharan

    2012-01-01

    Objective:To investigate the cytotoxic effect of Elaeis guineensis methanol extract on MCF-7and Vero cell.Methods:In vitro cytotoxicity was evaluated in by MTT assay.Cell morphological changes were observed by using light microscope.Results:The MTT assay indicated that methanol extract of the plant exhibited significant cytotoxic effects on MCF-7.Morphological alteration of the cell lines after exposure with lilaeis guineensis extract were observed under phase contrast microscope in the dose dependent manner.Conclusions:The results suggest the probable use of the Elaeis guineensis methanol extract in preparing recipes for cancer-related ailments.Further studies on isolation of metabolites and their in vivo cytotoxicity are under investigation.

  20. Synthesis of Chromonylthiazolidines and Their Cytotoxicity to Human Cancer Cell Lines

    Directory of Open Access Journals (Sweden)

    Hoang Le Tuan Anh

    2015-01-01

    Full Text Available Nine new chromonylthiazolidine derivatives were successfully semi-synthesized from paeonol. All of the compounds, including starting materials, the intermediate compound and products, were evaluated for their cytotoxic effects toward eight human cancer cell lines. The synthesized chromonylthiazolidines displayed weak cytotoxic effects against the tested cancer cell lines, but selective cytotoxic effects were observed. Compounds 3a and 3b showed the most selective cytotoxic effects against human epidermoid carcinoma (IC50 44.1 ± 3.6 μg/mL and breast cancer (IC50 32.8 ± 1.4 μg/mL cell lines, respectively. The results suggest that chromoylthiazolidines are potential low-cost, and selective anticancer agents.

  1. Protein kinase inhibitor-induced endothelial cell cytotoxicity and its prediction based on calculated molecular descriptors.

    Science.gov (United States)

    Herczenik, Eszter; Varga, Zoltán; Eros, Dániel; Makó, Veronika; Oroszlán, Melinda; Rugonfalvi-Kiss, Szabolcs; Romics, László; Füst, George; Kéri, György; Orfi, László; Cervenak, László

    2009-01-01

    Protein kinase inhibitors (PKIs) as potent signal transduction therapeutic compounds represent a very rapidly expanding group of anticancer drugs. These agents may be toxic for endothelial cells, however, very few experimental data exist on the cytotoxicity of PKIs. The aim of this study was to set up an appropriate test system for endothelial cells and to assess the structure-related cytotoxic effects of a selected library of PKIs. The inhibitor library contains several lead molecules with different basic structures and a set of modified derivatives of the lead compounds. The toxicity of PKIs did not correlate directly with the structural features of the molecules. However, we successfully built up a model based on 15 calculated molecular descriptors, which is capable of predicting cytotoxicity with acceptable probability. Our results show that the cytotoxic effects of PKIs should be taken into account for optimal drug development to overcome endothelial cell-related side effects. PMID:19519173

  2. Synergistic cytotoxicity of gemcitabine, clofarabine and edelfosine in lymphoma cell lines

    OpenAIRE

    Valdez, B C; Zander, A R; Song, G.; Murray, D; Nieto, Y; Li, Y.; Champlin, R E; Andersson, B. S.

    2014-01-01

    Treatments for lymphomas include gemcitabine (Gem) and clofarabine (Clo) which inhibit DNA synthesis. To improve their cytotoxicity, we studied their synergism with the alkyl phospholipid edelfosine (Ed). Exposure of the J45.01 and SUP-T1 (T-cell) and the OCI-LY10 (B-cell) lymphoma cell lines to IC10–IC20 levels of the drugs resulted in strong synergistic cytotoxicity for the 3-drug combination based on various assays of cell proliferation and apoptosis. Cell death correlated with increased p...

  3. Clustered Ergot Alkaloids Modulate Cell-mediated Cytotoxicity

    Czech Academy of Sciences Publication Activity Database

    Křen, Vladimír; Fišerová, Anna; Weignerová, Lenka; Stibor, I.; Halada, Petr; Přikrylová, Věra; Sedmera, Petr; Pospíšil, Miloslav

    2002-01-01

    Roč. 10, - (2002), s. 415-424. ISSN 0968-0896 R&D Projects: GA AV ČR IAA4020901; GA ČR GA310/98/0347 Institutional research plan: CEZ:AV0Z5020903 Keywords : clustered * ergot * alkaloids Subject RIV: EE - Microbiology, Virology Impact factor: 2.043, year: 2002

  4. Cellular Adjuvant Properties, Direct Cytotoxicity of Re-differentiated Vα24 Invariant NKT-like Cells from Human Induced Pluripotent Stem Cells

    Directory of Open Access Journals (Sweden)

    Shuichi Kitayama

    2016-02-01

    Full Text Available Vα24 invariant natural killer T (iNKT cells are a subset of T lymphocytes implicated in the regulation of broad immune responses. They recognize lipid antigens presented by CD1d on antigen-presenting cells and induce both innate and adaptive immune responses, which enhance effective immunity against cancer. Conversely, reduced iNKT cell numbers and function have been observed in many patients with cancer. To recover these numbers, we reprogrammed human iNKT cells to pluripotency and then re-differentiated them into regenerated iNKT cells in vitro through an IL-7/IL-15-based optimized cytokine combination. The re-differentiated iNKT cells showed proliferation and IFN-γ production in response to α-galactosylceramide, induced dendritic cell maturation and downstream activation of both cytotoxic T lymphocytes and NK cells, and exhibited NKG2D- and DNAM-1-mediated NK cell-like cytotoxicity against cancer cell lines. The immunological features of re-differentiated iNKT cells and their unlimited availability from induced pluripotent stem cells offer a potentially effective immunotherapy against cancer.

  5. Cellular Adjuvant Properties, Direct Cytotoxicity of Re-differentiated Vα24 Invariant NKT-like Cells from Human Induced Pluripotent Stem Cells

    Science.gov (United States)

    Kitayama, Shuichi; Zhang, Rong; Liu, Tian-Yi; Ueda, Norihiro; Iriguchi, Shoichi; Yasui, Yutaka; Kawai, Yohei; Tatsumi, Minako; Hirai, Norihito; Mizoro, Yasutaka; Iwama, Tatsuaki; Watanabe, Akira; Nakanishi, Mahito; Kuzushima, Kiyotaka; Uemura, Yasushi; Kaneko, Shin

    2016-01-01

    Summary Vα24 invariant natural killer T (iNKT) cells are a subset of T lymphocytes implicated in the regulation of broad immune responses. They recognize lipid antigens presented by CD1d on antigen-presenting cells and induce both innate and adaptive immune responses, which enhance effective immunity against cancer. Conversely, reduced iNKT cell numbers and function have been observed in many patients with cancer. To recover these numbers, we reprogrammed human iNKT cells to pluripotency and then re-differentiated them into regenerated iNKT cells in vitro through an IL-7/IL-15-based optimized cytokine combination. The re-differentiated iNKT cells showed proliferation and IFN-γ production in response to α-galactosylceramide, induced dendritic cell maturation and downstream activation of both cytotoxic T lymphocytes and NK cells, and exhibited NKG2D- and DNAM-1-mediated NK cell-like cytotoxicity against cancer cell lines. The immunological features of re-differentiated iNKT cells and their unlimited availability from induced pluripotent stem cells offer a potentially effective immunotherapy against cancer. PMID:26862702

  6. Natural mineral particles are cytotoxic to rainbow trout gill epithelial cells in vitro.

    Directory of Open Access Journals (Sweden)

    Christian Michel

    Full Text Available Worldwide increases in fluvial fine sediment are a threat to aquatic animal health. Fluvial fine sediment is always a mixture of particles whose mineralogical composition differs depending on the sediment source and catchment area geology. Nonetheless, whether particle impact in aquatic organisms differs between mineral species remains to be investigated. This study applied an in vitro approach to evaluate cytotoxicity and uptake of four common fluvial mineral particles (quartz, feldspar, mica, and kaolin; concentrations: 10, 50, 250 mg L(-1 in the rainbow trout epithelial gill cell line RTgill-W1. Cells were exposed for 24, 48, 72, and 96 h. Cytotoxicity assays for cell membrane integrity (propidium iodide assay, oxidative stress (H2DCF-DA assay, and metabolic activity (MTT assay were applied. These assays were complemented with cell counts and transmission electron microscopy. Regardless of mineral species, particles ≤ 2 µm in diameter were taken up by the cells, suggesting that particles of all mineral species came into contact and interacted with the cells. Not all particles, however, caused strong cytotoxicity: Among all assays the tectosilicates quartz and feldspar caused sporadic maximum changes of 0.8-1.2-fold compared to controls. In contrast, cytotoxicity of the clay particles was distinctly stronger and even differed between the two particle types: mica induced concentration-dependent increases in free radicals, with consistent 1.6-1.8-fold-changes at the 250 mg L(-1 concentration, and a dilated endoplasmic reticulum. Kaolin caused concentration-dependent increases in cell membrane damage, with consistent 1.3-1.6-fold increases at the 250 mg L(-1 concentration. All effects occurred in the presence or absence of 10% fetal bovine serum. Cell numbers per se were marginally affected. Results indicate that (i. natural mineral particles can be cytotoxic to gill epithelial cells, (ii. their cytotoxic potential differs between mineral

  7. Cytotoxic effects of tetracycline analogues (doxycycline, minocycline and COL-3 in acute myeloid leukemia HL-60 cells.

    Directory of Open Access Journals (Sweden)

    Hairong Song

    Full Text Available Tetracycline analogues (TCNAs have been shown to inhibit matrix metalloproteinases and to induce apoptosis in several cancer cell types. In the present study, the cytotoxic effects of TCNAs doxycycline (DOXY, minocycline (MINO and chemically modified tetracycline-3 (COL-3 were investigated in the human acute myeloid leukemia HL-60 cell line. Cells were incubated with TCNAs in final concentrations of 0.5-100 µg/ml for 24 h. Viability of the leukemic cells was inhibited in a concentration-dependent manner using resazurin assay. The estimated IC50s were 9.2 µg/ml for DOXY, 9.9 µg/ml for MINO and 1.3 µg/ml for COL-3. All three TCNAs induced potent cytotoxic effects and cell death. Apoptosis, which was assessed by morphological changes and annexin V positivity, was concentration- and time-dependent following incubation with any one of the drugs. TCNAs induced DNA double strand breaks soon after treatment commenced as detected by γH2AX and western blot. The loss of mitochondrial membrane potential (Δψm, caspase activation and cleavage of PARP and Bcl-2 were observed; however, the sequence of events differed among the drugs. Pancaspase inhibitor Z-VAD-FMK improved survival of TCNAs-treated cells and decreased TCNAs-induced apoptosis. In summary, we demonstrated that TCNAs had a cytotoxic effect on the HL-60 leukemic cell line. Apoptosis was induced via mitochondria-mediated and caspase-dependent pathways in HL-60 cells by all three TCNAs. COL-3 exerted the strongest anti-proliferative and pro-apoptotic effects in concentrations that have been achieved in human plasma in reported clinical trials. These results indicate that there is a therapeutic potential of TCNAs in leukemia.

  8. Iodobenzene diacetate-mediated isomerization of pyrazolyl chalcones and their cytotoxicity and anti-microbial activity

    Indian Academy of Sciences (India)

    Mahavir Parshad; Vikas Verma; Devinder Kumar; Balasubramanian Narasimhan; Smit Kour; Shashank Singh; Payare Lal Sangwan

    2015-03-01

    Synthesis of cis (E)-1-(5-hydroxy-3-methyl-1-phenyl-1H-pyrazol-4-yl)-3-phenyl/aryl/heteroarylprop-2-en-1-ones from 1-phenyl-3-methyl-4-acetylpyrazol-5-one was achieved in good yield. s-cis (E)-1-(5-Hydroxy-3-methyl-1-phenyl-1H-pyrazol-4-yl)-3-arylprop-2-en-1-ones were isomerized to s-trans (E)-4-(3-(phenyl/aryl/heteroaryl)acryloyl)-5-methyl-2-phenyl-1H-pyrazol-3(2H)-ones using iodobenzene diacetate in dichloromethane at room temperature in excellent yield. The structure and geometry of these , -unsaturated ketones (pyrazolyl ketones) were established with the help of NMR, 2D NMR and HRMS techniques. The cytotoxicity of pyrazolyl chalcones showed that s-cis (E) 1-(5-Hydroxy-3-methyl-1-phenyl-1H-pyrazol-4-yl)-3-(4-methylphenyl)-prop-2-en-1-one is active at very low concentrations (IC50 13.3 M) against colon cancer cell line (HCT-116). The in vitro anti-microbial studies of pyrazolyl chalcones were also tested against grampositive (B. subtilis, S. aureus) and gram-negative bacteria (E. coli) and for anti-fungal activity against C. albicans and A. niger.

  9. Differentiation of cytotoxicity using target cells labelled with europium and samarium by electroporation.

    Science.gov (United States)

    Bohlen, H; Manzke, O; Engert, A; Hertel, M; Hippler-Altenburg, R; Diehl, V; Tesch, H

    1994-07-12

    We report the simultaneous use of europium-DTPA (Eu-DTPA) and samarium-DTPA (Sm-DTPA) in cytotoxicity experiments to analyze simultaneously LAK and NK cell lysis and to differentiate between specific target lysis and bystander killing. The target cells were either labelled with Eu-DTPA or Sm-DTPA chelates by electroporation, which permits the use of target cell lines or primary leukemic B cells (B-CLL) that cannot be labelled by the conventional dextran-sulphate method. The release of europium and samarium reaches a maximum at comparable time intervals (2-3 h). Due to the shorter counting interval within the samarium window the labelling efficiency is about ten times less efficient compared to europium. Using europium as label for the LAK target Daudi and samarium as label for the NK sensitive cell line K562 the differentiation of LAK versus NK activity can be performed in a single culture assay. Also, the killing of B cells and bystander cells by cytotoxic T cells was analyzed in a system where T cells were redirected to B cells through CD3 x CD19 bispecific antibodies. In fact, no bystander killing was noted when bispecific antibodies were used to bridge cytotoxic T cells to the B cells. This approach provides a simple non-radioactive method for evaluating cytotoxicity against two different cells in a single culture well. PMID:8034986

  10. Differential cytotoxic effects of gold nanoparticles in different mammalian cell lines

    Energy Technology Data Exchange (ETDEWEB)

    Chueh, Pin Ju [Institute of Biomedical Sciences, National Chung Hsing University, Taichung 40227, Taiwan (China); Graduate Institute of Basic Medicine, China Medical University, Taichung 40402, Taiwan (China); Department of Medical Research, China Medical University Hospital, Taichung 40402, Taiwan (China); Department of Biotechnology, Asia University, Taichung 41354, Taiwan (China); Liang, Ruei-Yue; Lee, Yi-Hui; Zeng, Zih-Ming [Institute of Biomedical Sciences, National Chung Hsing University, Taichung 40227, Taiwan (China); Chuang, Show-Mei, E-mail: smchuang@dragon.nchu.edu.tw [Institute of Biomedical Sciences, National Chung Hsing University, Taichung 40227, Taiwan (China)

    2014-01-15

    Highlights: • AuNPs induce apoptosis in Vero cells. • AuNPs-induced attenuation of cell growth in NIH3T3 cells through autophagy. • Cell-cycle delay was associated with the resistance to AuNPs in MRC-5 cells. • Cell growth was continuously monitored using the measurement of cell impedance. -- Abstract: Gold nanoparticles (AuNPs) possess unique properties that have been exploited in several medical applications. However, a more comprehensive understanding of the environmental safety of AuNPs is imperative for use of these nanomaterials. Here, we describe the impacts of AuNPs in various mammalian cell models using an automatic and dye-free method for continuous monitoring of cell growth based on the measurement of cell impedance. Several well-established cytotoxicity assays were also used for comparison. AuNPs induced a concentration-dependent decrease in cell growth. This inhibitory effect was associated with apoptosis induction in Vero cells but not in MRC-5 or NIH3T3 cells. Interestingly, cDNA microarray analyses in MRC-5 cells supported the involvement of DNA damage and repair responses, cell-cycle regulation, and oxidative stress in AuNP-induced cytotoxicity and genotoxicity. Moreover, autophagy appeared to play a role in AuNPs-induced attenuation of cell growth in NIH3T3 cells. In this study, we present a comprehensive overview of AuNP-induced cytotoxicity in a variety of mammalian cell lines, comparing several cytotoxicity assays. Collectively, these assays offer convincing evidence of the cytotoxicity of AuNPs and support the value of a systematic approach for analyzing the toxicology of nanoparticles.

  11. Differential cytotoxic effects of gold nanoparticles in different mammalian cell lines

    International Nuclear Information System (INIS)

    Highlights: • AuNPs induce apoptosis in Vero cells. • AuNPs-induced attenuation of cell growth in NIH3T3 cells through autophagy. • Cell-cycle delay was associated with the resistance to AuNPs in MRC-5 cells. • Cell growth was continuously monitored using the measurement of cell impedance. -- Abstract: Gold nanoparticles (AuNPs) possess unique properties that have been exploited in several medical applications. However, a more comprehensive understanding of the environmental safety of AuNPs is imperative for use of these nanomaterials. Here, we describe the impacts of AuNPs in various mammalian cell models using an automatic and dye-free method for continuous monitoring of cell growth based on the measurement of cell impedance. Several well-established cytotoxicity assays were also used for comparison. AuNPs induced a concentration-dependent decrease in cell growth. This inhibitory effect was associated with apoptosis induction in Vero cells but not in MRC-5 or NIH3T3 cells. Interestingly, cDNA microarray analyses in MRC-5 cells supported the involvement of DNA damage and repair responses, cell-cycle regulation, and oxidative stress in AuNP-induced cytotoxicity and genotoxicity. Moreover, autophagy appeared to play a role in AuNPs-induced attenuation of cell growth in NIH3T3 cells. In this study, we present a comprehensive overview of AuNP-induced cytotoxicity in a variety of mammalian cell lines, comparing several cytotoxicity assays. Collectively, these assays offer convincing evidence of the cytotoxicity of AuNPs and support the value of a systematic approach for analyzing the toxicology of nanoparticles

  12. Novel CD8(+) cytotoxic T cell epitopes in bovine leukemia virus with cattle.

    Science.gov (United States)

    Bai, Lanlan; Takeshima, Shin-Nosuke; Isogai, Emiko; Kohara, Junko; Aida, Yoko

    2015-12-16

    Bovine leukemia virus (BLV) is associated with enzootic bovine leukosis and is closely related to human T cell leukemia virus (HTLV). The cytotoxic T lymphocyte (CTL) plays a key role in suppressing the progression of disease caused by BLV. T and B cell epitopes in BLV have been studied, but CD8(+) CTL epitopes remain poorly understood. We used a library of 115 synthetic peptides covering the entirety of the Env proteins (gp51 and gp30), the Gag proteins (p15, p24, and p12), and the Tax protein of BLV to identify 11 novel CD8(+) T cell epitopes (gp51N5, gp51N11, gp51N12, gp30N5, gp30N6, gp30N8, gp30N16, tax16, tax18, tax19, and tax20) in four calves experimentally infected with BLV. The number of CD8(+) T cell epitopes that could be identified in each calf correlated with the BLV proviral load. Interestingly, among the 11 epitopes identified, only gp51N11 was capable of inducing CD8(+) T cell-mediated cytotoxicity in all four calves, but it is not a suitable vaccine target because it shows a high degree of polymorphism according to the Wu-Kabat variability index. By contrast, no CTL epitopes were identified from the Gag structural protein. In addition, several epitopes were obtained from gp30 and Tax, indicating that cellular immunity against BLV is strongly targeted to these proteins. CD8(+) CTL epitopes from gp30 and Tax were less polymorphic than epitopes from. Indeed, peptides tax16, tax18, tax19, and tax20 include a leucine-rich activation domain that encompasses a transcriptional activation domain, and the gp30N16 peptide contains a proline-rich region that interacts with a protein tyrosine phosphatase SHP1 to regulate B cell activation. Moreover, at least one CD8(+) CTL epitope derived from gp30 was identified in each of the four calves. These results indicate that BLV gp30 may be the best candidate for the development of a BLV vaccine. PMID:26552001

  13. Cytotoxic effect of Cousinia verbascifolia Bunge against OVCAR-3 and HT-29 cancer cells

    Directory of Open Access Journals (Sweden)

    Sajjadi Seyed Ebrahim

    2015-01-01

    Full Text Available Introduction: Little information is available about phytochemical and biological properties of Cousinia genus. In a primary study, seven Cousinia species including C. verbascifolia showed cytotoxic activity ranged between 18.4 ± 0.59 to 87.9 ± 0.58 μg/mL. To the best of our knowledge, no other biological studies have been conducted on this plant. Therefore, in this study the cytotoxic effect of Cousinia verbascifolia Bunge against OVCAR-3 and HT-29 cancer cells was evaluated. Methods: Filtration and in vacuo concentration of methanol extract resulted in a green gum which was subjected on reverse column chromatography. Semi polar fraction (41.3 g eluted with water: methanol (20:80, was then subjected on a silica gel column chromatography using hexane/acetone and resulted in 11 fractions. Finally, cytotoxic activities against ovarian and colon cancer cells were determined at a wavelength of 570 nm by Matrix metalloproteinase protein (MTT standard method. Results: None of the fractions showed highly cytotoxic activity. Based on NCI, fractions Fr. 1, Fr. 2, Fr. 4, Fr. 5, Fr. 6, Fr. 8 and Fr. 10 showed moderately cytotoxicity with IC50 values ranged between 119 to 190 μg/mL against OVCAR-3 cells. Fractions Fr. 1, Fr. 2, Fr. 6, Fr. 7 and Fr. 8 showed moderately cytotoxic activity ranged between 118 to 194 μg/mL against HT-29 cells. Fr. 10 and Fr. 11 showed no cytotoxic activity. Conclusion: Due to the inhibitory properties of extract and its fractions on cancer cells, identification of responsible compounds possessing cytotoxic effects for generating possible new approach in medicinal chemistry are recommended.

  14. The cytotoxic effects a of ACA1 on human melanoma cell line

    Directory of Open Access Journals (Sweden)

    R. Yaraie

    2006-01-01

    Full Text Available Background and purpose: Different methods such as surgery, chemotherapy, radiotherapy, hormone therapy and immunotherapy are used for treatment of melanoma cancer. Unfortunately they don't always have desirable results and they may have unfavorable side effects. Researchers try to find new, more effective drugs with low side effects. In this study we evaluated the cytotoxic effect of ACA-1, a water extract of a traditional Iranian medicinal herbs on a melanoma cell line SKMEL-3.Materials and Methods: The SKMEL3 cell line was obtained from Pasture institute, Tehran, Iran and cultured in RPMI media supplemented with 10% FBS. Equal number of cells were added to a 96 well microplate and were incubated with various doses of ACA1 (5,2,1,0.2,0.1,0.05,0.02 and 0.01 mg/ml for 24, 48 and 72 hours in parallel. The cytotoxic effects of the drug was evaluated using MTT assay.Results: The Results showed that ACA1 has significant cytotoxic effects with dose and time dependent manner on SKMEL3. The optimum dose (5 mg/ml showed 47% cytotoxicity in 24 h, 65% cytotoxicity in 48 h and 71% cytotoxicity in 72 h. Conclusion: Based on the results of this research, ACA1 is a suitable candidate for chemotherapy of melanoma patients. Further studies are necessary in order to find effective drugs, their effects on other cell lines and approved in vivo models and clinical trials.

  15. Cytotoxicity of Selected Medicinal and Nonmedicinal Plant Extracts to Microbial and Cervical Cancer Cells

    Directory of Open Access Journals (Sweden)

    Gary M. Booth

    2012-01-01

    Full Text Available This study investigated the cytotoxicity of 55 species of plants. Each plant was rated as medicinal, or nonmedicinal based on the existing literature. About 79% of the medicinal plants showed some cytotoxicity, while 75% of the nonmedicinal plants showed bioactivity. It appears that Asteraceae, Labiatae, Pinaceae, and Chenopodiaceae were particularly active against human cervical cancer cells. Based on the literature, only three of the 55 plants have been significantly investigated for cytotoxicity. It is clear that there is much toxicological work yet to be done with both medicinal and nonmedicinal plants.

  16. Esters of Bendamustine Are by Far More Potent Cytotoxic Agents than the Parent Compound against Human Sarcoma and Carcinoma Cells.

    Directory of Open Access Journals (Sweden)

    Stefan Huber

    Full Text Available The alkylating agent bendamustine is approved for the treatment of hematopoietic malignancies such as non-Hodgkin lymphoma, chronic lymphocytic leukemia and multiple myeloma. As preliminary data on recently disclosed bendamustine esters suggested increased cytotoxicity, we investigated representative derivatives in more detail. Especially basic esters, which are positively charged under physiological conditions, were in the crystal violet and the MTT assay up to approximately 100 times more effective than bendamustine, paralleled by a higher fraction of early apoptotic cancer cells and increased expression of p53. Analytical studies performed with bendamustine and representative esters revealed pronounced cellular accumulation of the derivatives compared to the parent compound. In particular, the pyrrolidinoethyl ester showed a high enrichment in tumor cells and inhibition of OCT1- and OCT3-mediated transport processes, suggesting organic cation transporters to be involved. However, this hypothesis was not supported by the differential expression of OCT1 (SLC22A1 and OCT3 (SLC22A3, comparing a panel of human cancer cells. Bendamustine esters proved to be considerably more potent cytotoxic agents than the parent compound against a broad panel of human cancer cell types, including hematologic and solid malignancies (e.g. malignant melanoma, colorectal carcinoma and lung cancer, which are resistant to bendamustine. Interestingly, spontaneously immortalized human keratinocytes, as a model of "normal" cells, were by far less sensitive than tumor cells against the most potent bendamustine esters.

  17. Genipin-induced inhibition of uncoupling protein-2 sensitizes drug-resistant cancer cells to cytotoxic agents.

    Directory of Open Access Journals (Sweden)

    Ryan J Mailloux

    Full Text Available Uncoupling protein-2 (UCP2 is known to suppress mitochondrial reactive oxygen species (ROS production and is employed by drug-resistant cancer cells to mitigate oxidative stress. Using the drug-sensitive HL-60 cells and the drug-resistant MX2 subline as model systems, we show that genipin, a UCP2 inhibitor, sensitizes drug-resistant cells to cytotoxic agents. Increased MX2 cell death was observed upon co-treatment with genipin and different doses of menadione, doxorubicin, and epirubicin. DCFH-DA fluorimetry revealed that the increase in MX2 cell death was accompanied by enhanced cellular ROS levels. The drug-induced increase in ROS was linked to genipin-mediated inhibition of mitochondrial proton leak. State 4 and resting cellular respiratory rates were higher in the MX2 cells in comparison to the HL-60 cells, and the increased respiration was readily suppressed by genipin in the MX2 cells. UCP2 accounted for a remarkable 37% of the resting cellular oxygen consumption indicating that the MX2 cells are functionally reliant on this protein. Higher amounts of UCP2 protein were detected in the MX2 versus the HL-60 mitochondria. The observed effects of genipin were absent in the HL-60 cells pointing to the selectivity of this natural product for drug-resistant cells. The specificity of genipin for UCP2 was confirmed using CHO cells stably expressing UCP2 in which genipin induced an ∼22% decrease in state 4 respiration. These effects were absent in empty vector CHO cells expressing no UCP2. Thus, the chemical inhibition of UCP2 with genipin sensitizes multidrug-resistant cancer cells to cytotoxic agents.

  18. Stability of artemisinin in aqueous environments : Impact on its cytotoxic action to Ehrlich ascites tumour cells

    NARCIS (Netherlands)

    Beekman, AC; Woerdenbag, HJ; Van Uden, W; Pras, N; Konings, AWT; Wikstrom, HV

    1997-01-01

    We have recently shown artemisinin to be cytotoxic against Ehrlich ascites tumour cells. The aim of this study was to investigate the stability of this compound in the aqueous environment of the in-vitro Ehrlich ascites tumour cell system (RPMI 1640 cell culture medium supplemented with 10% foetal b

  19. Romidepsin enhances the cytotoxicity of fludarabine, clofarabine and busulfan combination in malignant T-cells.

    Science.gov (United States)

    Valdez, Benigno C; Brammer, Jonathan E; Li, Yang; Murray, David; Teo, Esmeralda C; Liu, Yan; Hosing, Chitra; Nieto, Yago; Champlin, Richard E; Andersson, Borje S

    2016-08-01

    Novel approaches to pre-transplant conditioning are needed to improve treatment of advanced T-cell malignancies. We investigated the synergism of fludarabine (Flu), clofarabine (Clo), busulfan (Bu), and romidepsin (Rom) in T-cell lines and patient-derived cell samples. [Flu+Clo+Bu+Rom] had combination indexes of 0.4-0.5 at ∼50% cytotoxicity in PEER and SUPT1 cells, suggesting synergism. Drug exposure resulted in histone modifications, DNA-damage response (DDR), increased reactive oxygen species (ROS), decreased glutathione (GSH) and mitochondrial membrane (MM) potential, and apoptosis. Similar activation of DDR and apoptosis was observed in patient samples. The PI3K-AKT-mTOR, NFκB, Raf-MEK-ERK, JAK-STAT and Wnt/β-catenin pro-survival pathways were inhibited by the 4-drug combination. The SAPK/JNK stress pathway was activated. A novel finding was the down-regulation of the drug transporter MRP1. We propose the following mechanisms of synergism: Flu, Clo and Rom induce histone modifications and chromatin remodeling, exposing DNA to Bu alkylation; the increased production of ROS, due to drug-mediated stress response and decreased GSH, damages the MM causing leakage of pro-apoptotic factors; down-regulation of MRP1 increases intracellular Bu concentration and exacerbates the DDR; and inhibition of multiple survival pathways. Our results provide the basis for a clinical trial to evaluate [Flu+Clo+Bu+Rom] as part of conditioning regimen for refractory T-cell malignancy patients undergoing stem cell transplantation. PMID:27294334

  20. Modulation of CYP3A4 activity alters the cytotoxicity of lipophilic phycotoxins in human hepatic HepaRG cells.

    Science.gov (United States)

    Ferron, P J; Hogeveen, K; De Sousa, G; Rahmani, R; Dubreil, E; Fessard, V; Le Hegarat, L

    2016-06-01

    The aim of this study was to investigate (i) the cytotoxic effects of lipophilic phycotoxins, including okadaic acid (OA) and dinophysistoxin-1 and -2 (DTX-1 and DTX-2), pectenotoxin-2 (PTX-2), yessotoxin (YTX), spirolide (SPX), and azaspiracids-1, -2 and -3 (AZA-1, AZA-2 and AZA-3), in human HepaRG cells using a multiparametric high content analysis approach, (ii) the ability of nine lipophilic phycotoxins to act as PXR agonists in a HepG2-PXR cell line, (iii) their potential to induce CYP450 activity, and (iv) the role of CYP3A4 in cytotoxicity induced by lipophilic phycotoxins. Our results indicate that while OA, DTX-1 and DTX-2 activated PXR-dependent transcriptional activity in HepG2 cells, no increase of CYP450 (1A2, 3A4, 2C9, 2C19) activities were observed in HepaRG cell following a 72h treatment with these toxins. Multiparametric analysis showed that OA, DTX-1, DTX-2, and PTX-2 were highly cytotoxic in HepaRG cells; inducing cell loss, activation of caspase-3 and γ-H2AX formation. However, no toxicity was observed for YTX, SPX, and AZAs. Moreover, we found that inhibition of CYP3A4 activity by ketoconazole enhances the toxic effects of OA, DTX-1, DTX-2, and PTX-2 in HepaRG cells. Taken together, these results suggest that CYP3A4-mediated metabolism of some lipophilic phycotoxins decreases their in vitro toxicity. PMID:26956883

  1. Cytotoxic Activity and G1 Cell Cycle Arrest of a Dienynone from Echinacea pallida

    DEFF Research Database (Denmark)

    Chicca, Andrea; Adinolfi, Barbara; Pellati, Federica; Orlandini, Giulia; Benvenuti, Stefania; Nieri, Paola

    2009-01-01

    (Jurkat and HL-60), breast carcinoma (MCF-7), and melanoma (MeWo) cells. As part of its mechanism of action, the ability of this constituent to arrest the cell cycle in the G1 phase was demonstrated on HL-60 cells. Furthermore, a stability test of the target compound over 72 h was carried out, indicating......In the present study, a further investigation of the cytotoxic activity of an acetylenic constituent of ECHINACEA PALLIDA roots, namely, pentadeca-(8 Z,13 Z)-dien-11-yn-2-one, was performed, revealing a concentration-dependent cytotoxicity on several human cancer cell lines, including leukemia...

  2. Human herpesvirus-6 enhances natural killer cell cytotoxicity via IL-15.

    OpenAIRE

    Flamand, L.; Stefanescu, I.(Argonne National Laboratory, Argonne, IL, 60439, USA); Menezes, J.

    1996-01-01

    The marked tropism of human herpesvirus-6 (HHV-6) for natural killer (NK) cells and T lymphocytes has led us to investigate the effect of HHV-6 on cellular cytotoxicity. We describe here how HHV-6 infection of peripheral blood mononuclear cells (PBMC) leads to upregulation of their NK cell cytotoxicity. The induction of NK cell activity by HHV-6 was abrogated by monoclonal antibodies (mAbs) to IL-15 but not by mAbs to other cytokines (IFN-alpha, IFN-gamma, TNF-alpha, TNF-beta, IL-2, IL-12) su...

  3. Producing ultrapure wood cellulose nanofibrils and evaluating the cytotoxicity using human skin cells.

    Science.gov (United States)

    Nordli, Henriette Rogstad; Chinga-Carrasco, Gary; Rokstad, Anne Mari; Pukstad, Brita

    2016-10-01

    Wood cellulose nanofibrils (CNF) have been suggested as a potential wound healing material, but its utilization is limited by FDA requirements regarding endotoxin levels. In this study a method using sodium hydroxide followed by TEMPO mediated oxidation was developed to produce ultrapure cellulose nanofibrils, with an endotoxin level of 45 endotoxin units/g (EU/g) cellulose. Scanning transmission electron microscopy (S(T)EM) revealed a highly nanofibrillated structure (lateral width of 3.7±1.3nm). Assessment of cytotoxicity and metabolic activity on Normal Human Dermal Fibroblasts and Human Epidermal Keratinocytes was done. CNF-dispersion of 50μg/ml did not affect the cells. CNF-aerogels induced a reduction of metabolic activity by the fibroblasts and keratinocytes, but no significant cell death. Cytokine profiling revealed no induction of the 27 cytokines tested upon exposure to CNF. The moisture-holding capacity of aerogels was relatively high (∼7500%), compared to a commercially available wound dressing (∼2500%), indicating that the CNF material is promising as dressing material for management of wounds with a moderate to high amount of exudate. PMID:27312614

  4. Cytotoxic activity of water extracts of Trichilia hirta leaves on human tumor cells

    International Nuclear Information System (INIS)

    Trichilia hirta L. (Meliaceae) is traditionally used by patients suffering from cancer as an antitumoral resource. Therefore, the objectives of this study were to evaluate the cytotoxic activity of water extracts of Trichilia hirta leaves on tumour cells and identify through a phytochemical screening the principal families of phytocomponents contained in these extracts. The cytotoxic activity of these extracts was also evaluated on human melanoma cells (SK-mel-3) and human breast carcinoma (T-47D). The African green monkey kidney (AGMK) cells Cercopithecus aethiops (Vero) were used as a non-tumour cells control. The results showed the presence of triterpenes/steroids, saponins, coumarins, reductor sugars, phenols and tannins, flavonoids and carbohydrates/glycosides in the extracts. The water leaf extracts showed cytotoxic activity mainly on tumour cells, which contributes to explain the referred recovery by patients suffering form cancer that traditionally consume these extracts

  5. Cellular uptake and cytotoxicity of positively charged chitosan gold nanoparticles in human lung adenocarcinoma cells

    International Nuclear Information System (INIS)

    Cellular uptake, cytotoxicity, and mechanisms of cytotoxicity of the positively charged Au nanoparticles (NPs) were examined in A549 cells, which are one of the most characterized pulmonary cellular systems. Positively charged Au NPs were prepared by chemical reduction using chitosan. The dimension and surface charge of Au NPs were examined by transmission electron microscopy (TEM), dynamic light scattering, and zeta potential measurements. The uptake of Au NPs into A549 cells was also monitored using TEM and dark-field microscopy (DFM) and z-stack confocal microRaman spectroscopy. DFM live cell imaging was also performed to monitor the entry of chitosan Au NPs in real time. The cytotoxic assay, using both methylthiazol tetrazolium and lactate dehydrogenase assays revealed that positively charged Au NPs decreased cell viability. Flow cytometry, DNA fragmentation, real-time PCR, and western blot analysis suggest that positively charged chitosan Au NPs provoke cell damage through both apoptotic and necrotic pathways.

  6. Cytotoxicity of Buah Merah (Pandanus conoideus Lamk.) Extract on Breast Cancer Cell Line (T47D)

    OpenAIRE

    Tri R Nuringtyas; Yoga Pratama; Galih G; Subagus Wahyuono; Sukarti Moeljopawiro

    2015-01-01

    Buah Merah (Pandanus conoideus Lamk.) has been extensively used to treat various diseases includingcancer. There are many varieties of buah merah and there was no scientifi c study comparing cytotoxicity ofdifferent varieties. The objective of this study was to investigate the cytotoxicity of three varieties of buah merahknown as Barugum, Maler and Yanggiru on breast cancer cell line (T47D). All samples were collected fromPapua, Indonesia. Each sample was extracted consecutively using three s...

  7. Cytotoxicity of Selected Medicinal and Nonmedicinal Plant Extracts to Microbial and Cervical Cancer Cells

    OpenAIRE

    Gary M. Booth; Malmstrom, Robert D.; Erica Kipp; Alexandra Paul

    2012-01-01

    This study investigated the cytotoxicity of 55 species of plants. Each plant was rated as medicinal, or nonmedicinal based on the existing literature. About 79% of the medicinal plants showed some cytotoxicity, while 75% of the nonmedicinal plants showed bioactivity. It appears that Asteraceae, Labiatae, Pinaceae, and Chenopodiaceae were particularly active against human cervical cancer cells. Based on the literature, only three of the 55 plants have been significantly investigated for cytoto...

  8. Arecoline induced cell cycle arrest, apoptosis, and cytotoxicity to human endothelial cells.

    Science.gov (United States)

    Tseng, Shuei-Kuen; Chang, Mei-Chi; Su, Cheng-Yao; Chi, Lin-Yang; Chang, Jenny Zwei-Ching; Tseng, Wan-Yu; Yeung, Sin-Yuet; Hsu, Ming-Lun; Jeng, Jiiang-Huei

    2012-08-01

    Betel quid (BQ) chewing is a common oral habit in South Asia and Taiwan. BQ consumption may increase the risk of oral squamous cell carcinoma (OSCC), oral submucous fibrosis (OSF), and periodontitis as well as systemic diseases (atherosclerosis, hypertension, etc.). However, little is known about the toxic effect of BQ components on endothelial cells that play important roles for angiogenesis, carcinogenesis, tissue fibrosis, and cardiovascular diseases. EAhy 926 (EAHY) endothelial cells were exposed to arecoline, a major BQ alkaloid, for various time periods. Cytotoxicity was estimated by 3-(4, 5- dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide assay. The cell cycle distribution of EAHY cells residing in sub-G0/G1, G0/G1, S-, and G2/M phases was analyzed by propidium iodide staining of cellular DNA content and flow cytometry. Some EAHY cells retracted, became round-shaped in appearance, and even detached from the culture plate after exposure to higher concentrations of arecoline (> 0.4 mM). At concentrations of 0.4 and 0.8 mM, arecoline induced significant cytotoxicity to EAHY cells. At similar concentrations, arecoline induced G2/M cell cycle arrest and increased sub-G0/G1 population, a hallmark of apoptosis. Interestingly, prolonged exposure to arecoline (0.1 mM) for 12 and 21 days significantly suppressed the proliferation of EAHY cells, whereas EAHY cells showed adaptation and survived when exposed to 0.05 mM arecoline. These results suggest that BQ components may contribute to the pathogenesis of OSF and BQ chewing-related cardiovascular diseases via toxicity to oral or systemic endothelial cells, leading to impairment of vascular function. During BQ chewing, endothelial damage may be induced by areca nut components and associate with the pathogenesis of OSF, periodontitis, and cardiovascular diseases. PMID:21847594

  9. Cytotoxicity of protein corona-graphene oxide nanoribbons on human epithelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Mbeh, Doris A. [Laboratory for Innovation and Analysis of Bio-Performance, École Polytechnique, C.P. 6079, Succursale Centre-ville, Montréal, Québec H3C 3A7 (Canada); Akhavan, Omid, E-mail: oakhavan@sharif.edu [Department of Physics, Sharif University of Technology, P.O. Box 11155-9161, Tehran (Iran, Islamic Republic of); Institute for Nanoscience and Nanotechnology, Sharif University of Technology, P.O. Box 14588-89694, Tehran (Iran, Islamic Republic of); Javanbakht, Taraneh [Laboratory for Innovation and Analysis of Bio-Performance, École Polytechnique, C.P. 6079, Succursale Centre-ville, Montréal, Québec H3C 3A7 (Canada); Mahmoudi, Morteza [Department of Nanotechnology, Faculty of Pharmacy, Tehran University of Medical Sciences (Iran, Islamic Republic of); Yahia, L’Hocine [Laboratory for Innovation and Analysis of Bio-Performance, École Polytechnique, C.P. 6079, Succursale Centre-ville, Montréal, Québec H3C 3A7 (Canada)

    2014-11-30

    Highlights: • Graphene oxide nanoribons (GONRs) were synthesized by unzipping of multi-walled carbon nanotubes. • GONRs were functionalized by the albumin originated from the two different protein sources. • Concentration-dependent cytotoxicity of the functionalized GONRs was investigated on human epithelial cells. - Abstract: Graphene oxide nanoribbons (GONRs) were synthesized using an oxidative unzipping of multi-walled carbon nanotubes. The interactions of the GONRs with various concentrations of fetal bovine serum or human plasma serum indicated that the GONRs were functionalized substantially by the albumin originated from the two different protein sources. Then, concentration-dependent cytotoxicity of the protein-functionalized GONRs on human epithelial cells was studied. Although the GONRs with concentrations ≤50 μg/mL did not exhibit significant cytotoxicity on the cells (with the cell viability >85%), the concentration of 100 μg/mL exhibited significant cytotoxicity including prevention of cell proliferation and induction of cell apoptosis. These results can provide more in-depth understanding about cytotoxic effects of graphene nanostructures which can be functionalized by the proteins of media.

  10. Cytotoxicity of protein corona-graphene oxide nanoribbons on human epithelial cells

    International Nuclear Information System (INIS)

    Highlights: • Graphene oxide nanoribons (GONRs) were synthesized by unzipping of multi-walled carbon nanotubes. • GONRs were functionalized by the albumin originated from the two different protein sources. • Concentration-dependent cytotoxicity of the functionalized GONRs was investigated on human epithelial cells. - Abstract: Graphene oxide nanoribbons (GONRs) were synthesized using an oxidative unzipping of multi-walled carbon nanotubes. The interactions of the GONRs with various concentrations of fetal bovine serum or human plasma serum indicated that the GONRs were functionalized substantially by the albumin originated from the two different protein sources. Then, concentration-dependent cytotoxicity of the protein-functionalized GONRs on human epithelial cells was studied. Although the GONRs with concentrations ≤50 μg/mL did not exhibit significant cytotoxicity on the cells (with the cell viability >85%), the concentration of 100 μg/mL exhibited significant cytotoxicity including prevention of cell proliferation and induction of cell apoptosis. These results can provide more in-depth understanding about cytotoxic effects of graphene nanostructures which can be functionalized by the proteins of media

  11. The neuropeptide alpha-melanocyte-stimulating hormone is critically involved in the development of cytotoxic CD8+ T cells in mice and humans.

    Directory of Open Access Journals (Sweden)

    Karin Loser

    Full Text Available BACKGROUND: The neuropeptide alpha-melanocyte-stimulating hormone is well known as a mediator of skin pigmentation. More recently, it has been shown that alpha-melanocyte-stimulating hormone also plays pivotal roles in energy homeostasis, sexual function, and inflammation or immunomodulation. Alpha-melanocyte-stimulating hormone exerts its antiinflammatory and immunomodulatory effects by binding to the melanocortin-1 receptor, and since T cells are important effectors during immune responses, we investigated the effects of alpha-melanocyte-stimulating hormone on T cell function. METHODOLOGY/PRINCIPAL FINDINGS: T cells were treated with alpha-melanocyte-stimulating hormone, and subsequently, their phenotype and function was analyzed in a contact allergy as well as a melanoma model. Furthermore, the relevance of alpha-melanocyte-stimulating hormone-mediated signaling for the induction of cytotoxicity was assessed in CD8(+ T cells from melanoma patients with functional and nonfunctional melanocortin-1 receptors. Here we demonstrate that the melanocortin-1 receptor is expressed by murine as well as human CD8(+ T cells, and we furthermore show that alpha-melanocyte-stimulating hormone/melanocortin-1 receptor-mediated signaling is critical for the induction of cytotoxicity in human and murine CD8(+ T cells. Upon adoptive transfer, alpha-melanocyte-stimulating hormone-treated murine CD8(+ T cells significantly reduced contact allergy responses in recipient mice. Additionally, the presented data indicate that alpha-melanocyte-stimulating hormone via signaling through a functional melanocortin-1 receptor augmented antitumoral immunity by up-regulating the expression of cytotoxic genes and enhancing the cytolytic activity in tumor-specific CD8(+ T cells. CONCLUSIONS/SIGNIFICANCE: Together, these results point to an important role of alpha-melanocyte-stimulating hormone in MHC class I-restricted cytotoxicity. Therefore, treatment of contact allergies or

  12. Cytotoxic Efficacy of Photodynamic Therapy in Osteosarcoma Cells In Vitro

    OpenAIRE

    Meier, Daniela; Campanile, Carmen; Botter, Sander M.; Born, Walter; Fuchs, Bruno

    2014-01-01

    In recent years, there has been the difficulty in finding more effective therapies against cancer with less systemic side effects. Therefore Photodynamic Therapy is a novel approach for a more tumor selective treatment. Photodynamic Therapy (PDT) that makes use of a nontoxic photosensitizer (PS), which, upon activation with light of a specific wavelength in the presence of oxygen, generates oxygen radicals that elicit a cytotoxic response(1). Despite its approval almost twenty years ago by th...

  13. The cytotoxicity and genotoxicity of soluble and particulate cobalt in human lung fibroblast cells

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Leah J.; Holmes, Amie L. [Wise Laboratory of Environmental and Genetic Toxicology, University of Southern Maine, 96 Falmouth St., P.O. Box 9300, Portland, ME 04101-9300 (United States); Maine Center for Environmental Toxicology and Health, University of Southern Maine, 96 Falmouth St., P.O. Box 9300, Portland, ME 04101-9300 (United States); Department of Applied Medical Science, University of Southern Maine, 96 Falmouth St., P.O. Box 9300, Portland, ME 04101-9300 (United States); Kandpal, Sanjeev Kumar; Mason, Michael D. [Department of Chemical and Biological Engineering, University of Maine, Orono, ME (United States); Zheng, Tongzhang [Department of Environmental Health Sciences, Yale School of Public Health, New Haven, CT (United States); Wise, John Pierce, E-mail: John.Wise@usm.maine.edu [Wise Laboratory of Environmental and Genetic Toxicology, University of Southern Maine, 96 Falmouth St., P.O. Box 9300, Portland, ME 04101-9300 (United States); Maine Center for Environmental Toxicology and Health, University of Southern Maine, 96 Falmouth St., P.O. Box 9300, Portland, ME 04101-9300 (United States); Department of Applied Medical Science, University of Southern Maine, 96 Falmouth St., P.O. Box 9300, Portland, ME 04101-9300 (United States)

    2014-08-01

    Cobalt exposure is increasing as cobalt demand rises worldwide due to its use in enhancing rechargeable battery efficiency, super-alloys, and magnetic products. Cobalt is considered a possible human carcinogen with the lung being a primary target. However, few studies have considered cobalt-induced toxicity in human lung cells. Therefore, in this study, we sought to determine the cytotoxicity and genotoxicity of particulate and soluble cobalt in human lung cells. Cobalt oxide and cobalt chloride were used as representative particulate and soluble cobalt compounds, respectively. Exposure to both particulate and soluble cobalt induced a concentration-dependent increase in cytotoxicity, genotoxicity, and intracellular cobalt ion levels. Based on intracellular cobalt ion levels, we found that soluble cobalt was more cytotoxic than particulate cobalt while particulate and soluble cobalt induced similar levels of genotoxicity. However, soluble cobalt induced cell cycle arrest indicated by the lack of metaphases at much lower intracellular cobalt concentrations compared to cobalt oxide. Accordingly, we investigated the role of particle internalization in cobalt oxide-induced toxicity and found that particle-cell contact was necessary to induce cytotoxicity and genotoxicity after cobalt exposure. These data indicate that cobalt compounds are cytotoxic and genotoxic to human lung fibroblasts, and solubility plays a key role in cobalt-induced lung toxicity. - Highlights: • Particulate and soluble cobalt are cytotoxic and genotoxic to human lung cells. • Soluble cobalt induces more cytotoxicity compared to particulate cobalt. • Soluble and particulate cobalt induce similar levels of genotoxicity. • Particle-cell contact is required for particulate cobalt-induced toxicity.

  14. The cytotoxicity of nitroaromatic hypoxic cell radiosensitizers on mammalian cells in vitro

    International Nuclear Information System (INIS)

    The cytotoxic action of several representative nitroaromatic compounds towards Chinese hamster V79 cells in vitro was investigated. Particular reference is made to the 2-nitroimidazole, misonidazole. The results showed that compounds, which are likely to affect the rate and extent of reduction of the nitro group, can alter the cytotoxicity of nitroaromatic compounds under hypoxic conditions. Inhibition of oxygen utilization in aerobic cells by respiratory inhibitors can be relieved by the addition of misonidazole. The presence of these inhibitors or exogenous compounds which can act as energy sources, can change the survival response of mammalian cells to misonidazole both aerobic and hypoxic conditions. Post-incubation of cells in caffeine after exposure to either misonidazole, metronidazole or nitrofurantoin accentuates the degree of cell-killing, probably by inhibition of repair of DNA damage. Several of these nitroaromatic compounds are weakly mutagenic, as demonstrated by resistance to the toxic action of Ouabain and Thioguanine. The mechanistic implications of these results and the relevance to the use of these compounds in cancer therapy are discussed. (author)

  15. A Leukocyte Immune-Type Receptor Subset Is a Marker of Antiviral Cytotoxic Cells in Channel Catfish, Ictalurus punctatus.

    Science.gov (United States)

    Taylor, Erin B; Moulana, Mohadetheh; Stuge, Tor B; Quiniou, Sylvie M A; Bengten, Eva; Wilson, Melanie

    2016-03-15

    Channel catfish, Ictalurus punctatus, leukocyte immune type receptors (LITRs) represent a multigene family that encodes Ig superfamily proteins that mediate activating or inhibitory signaling. In this study, we demonstrate the use of mAb CC41 to monitor viral cytotoxic responses in catfish and determine that CC41 binds to a subset of LITRs on the surface of catfish clonal CTLs. Homozygous gynogenetic catfish were immunized with channel catfish virus (CCV)-infected MHC-matched clonal T cells (G14D-CCV), and PBL were collected at various times after immunization for flow cytometric analyses. The percentage of CC41(+) cells was significantly increased 5 d after primary immunization with G14D-CCV and at 3 d after a booster immunization as compared with control fish only injected with G14D. Moreover, CC41(+) cells magnetically isolated from the PBL specifically killed CCV-infected targets as measured by (51)Cr release assays and expressed messages for CD3γδ, perforin, and at least one of the CD4-like receptors as analyzed by RNA flow cytometry. When MLC effector cells derived from a G14D-CCV-immunized fish were preincubated with CC41 mAb, killing of G14D-CCV targets was reduced by ∼40%, suggesting that at least some LITRs have a role in target cell recognition and/or cytotoxicity. The availability of a LITR-specific mAb has allowed, to our knowledge for the first time, functional characterization of LITRs in an autologous system. In addition, the identification of an LITR subset as a cytotoxic cell marker will allow for more effective monitoring of catfish immune responses to pathogens. PMID:26856701

  16. Melatonin Cytotoxicity Is Associated to Warburg Effect Inhibition in Ewing Sarcoma Cells

    Science.gov (United States)

    Sanchez-Sanchez, Ana M.; Antolin, Isaac; Puente-Moncada, Noelia; Suarez, Santos; Gomez-Lobo, Marina; Rodriguez, Carmen; Martin, Vanesa

    2015-01-01

    Melatonin kills or inhibits the proliferation of different cancer cell types, and this is associated with an increase or a decrease in reactive oxygen species, respectively. Intracellular oxidants originate mainly from oxidative metabolism, and cancer cells frequently show alterations in this metabolic pathway, such as the Warburg effect (aerobic glycolysis). Thus, we hypothesized that melatonin could also regulate differentially oxidative metabolism in cells where it is cytotoxic (Ewing sarcoma cells) and in cells where it inhibits proliferation (chondrosarcoma cells). Ewing sarcoma cells but not chondrosarcoma cells showed a metabolic profile consistent with aerobic glycolysis, i.e. increased glucose uptake, LDH activity, lactate production and HIF-1α activation. Melatonin reversed Ewing sarcoma metabolic profile and this effect was associated with its cytotoxicity. The differential regulation of metabolism by melatonin could explain why the hormone is harmless for a wide spectrum of normal and only a few tumoral cells, while it kills specific tumor cell types. PMID:26252771

  17. Inhibition of the accumulation, in rat kidney allografts, of specific--but not nonspecific--cytotoxic cells by cyclosporine

    International Nuclear Information System (INIS)

    Rats receiving kidney allografts were divided into two groups--one was treated daily with an immunosuppressive dose of cyclosporine and the other group was left untreated. Five days after transplantation the cells infiltrating the grafts were extracted by enzymic treatment and tested in vitro for specific and nonspecific cytotoxicity in a 6-hr 51Cr release assay. Approximately 5 X 10(7) and 7 X 10(7) mononuclear cells per kidney were obtained, respectively, from healthy grafts excised from cyclosporine-treated hosts and from grafts undergoing unmodified rejection. Despite these similarities in yield the cells harvested from the grafts of the two groups showed very different cytolytic activity. Cells from both sources displayed comparable levels of nonspecific cytotoxicity, but only those obtained from grafts undergoing rejection were able to mediate specific target cell lysis. The relevance of these observations to the understanding of the mechanism of kidney allograft rejection in the rat and of the mode of action of cyclosporine are briefly discussed

  18. Antibody-dependent cellular cytotoxicity-mediating antibodies from an HIV-1 vaccine efficacy trial target multiple epitopes and preferentially use the VH1 gene family.

    Science.gov (United States)

    Bonsignori, Mattia; Pollara, Justin; Moody, M Anthony; Alpert, Michael D; Chen, Xi; Hwang, Kwan-Ki; Gilbert, Peter B; Huang, Ying; Gurley, Thaddeus C; Kozink, Daniel M; Marshall, Dawn J; Whitesides, John F; Tsao, Chun-Yen; Kaewkungwal, Jaranit; Nitayaphan, Sorachai; Pitisuttithum, Punnee; Rerks-Ngarm, Supachai; Kim, Jerome H; Michael, Nelson L; Tomaras, Georgia D; Montefiori, David C; Lewis, George K; DeVico, Anthony; Evans, David T; Ferrari, Guido; Liao, Hua-Xin; Haynes, Barton F

    2012-11-01

    The ALVAC-HIV/AIDSVAX-B/E RV144 vaccine trial showed an estimated efficacy of 31%. RV144 secondary immune correlate analysis demonstrated that the combination of low plasma anti-HIV-1 Env IgA antibodies and high levels of antibody-dependent cellular cytotoxicity (ADCC) inversely correlate with infection risk. One hypothesis is that the observed protection in RV144 is partially due to ADCC-mediating antibodies. We found that the majority (73 to 90%) of a representative group of vaccinees displayed plasma ADCC activity, usually (96.2%) blocked by competition with the C1 region-specific A32 Fab fragment. Using memory B-cell cultures and antigen-specific B-cell sorting, we isolated 23 ADCC-mediating nonclonally related antibodies from 6 vaccine recipients. These antibodies targeted A32-blockable conformational epitopes (n = 19), a non-A32-blockable conformational epitope (n = 1), and the gp120 Env variable loops (n = 3). Fourteen antibodies mediated cross-clade target cell killing. ADCC-mediating antibodies displayed modest levels of V-heavy (VH) chain somatic mutation (0.5 to 1.5%) and also displayed a disproportionate usage of VH1 family genes (74%), a phenomenon recently described for CD4-binding site broadly neutralizing antibodies (bNAbs). Maximal ADCC activity of VH1 antibodies correlated with mutation frequency. The polyclonality and low mutation frequency of these VH1 antibodies reveal fundamental differences in the regulation and maturation of these ADCC-mediating responses compared to VH1 bNAbs. PMID:22896626

  19. In vitro evaluation of cytotoxicity of engineered carbon nanotubes in selected human cell lines

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Xiaoke; Cook, Sean; Wang, Peng [Department of Biology, Jackson State University, P.O. Box 18540, Jackson, MS 39217 (United States); Hwang, Huey-min, E-mail: huey-min.hwang@jsums.edu [Department of Biology, Jackson State University, P.O. Box 18540, Jackson, MS 39217 (United States); Liu, Xi; Williams, Quinton L. [Department of Physics, Atmospheric Sciences and Geoscience, Jackson State University, P.O. Box 17660, Jackson, MS 39217 (United States)

    2010-03-15

    In this study, we used a systematic approach to study and compare the in vitro cytotoxicity of selected engineered carbon nanotubes (CNTs) to test cell lines including human skin keratinocytes, lung cells and lymphocytes. Results of fluorescein diacetate (FDA) uptake in T4 lymphocyte A3 cells indicated cytotoxicity caused by single-walled carbon nanotubes (SWCNTs) at concentrations of 2, 5 and 10 ppm. At 2 ppm, the SWCNT treatment group retained 71.3% viability compared to the PBS control group. At 10 ppm, cellular viability further decreased to 56.5% of the PBS control group. In the skin keratinocyte HaCaT cells and lung MSTO-211H cells, the SWCNT did not demonstrate any cytotoxicity at concentrations of 2 and 5 ppm but slightly inhibited HaCaT cells and caused significant toxicity to MSTO-211H cells at 10 ppm. Multi-walled carbon nanotube (MWCNT) testing showed significant cytotoxicity to A3 cells in a dose-dependent manner. At 10 ppm the viability of the cells decreased to 89.1% compared to the PBS control. In MSTO-211H cells, MWCNT caused significant toxicity at concentrations of 2 ppm and higher. By comparison, HaCaT cells were inhibited significantly only at 10 ppm. Overall, the test CNTs inhibited cellular viabilities in a concentration, cell type, and CNT type-dependent pattern. The viabilities of the MWCNT-impacted cells are higher than the corresponding SWCNT groups. We speculate that on a per volume basis, the greater availability of defects and contaminants for cellular interaction may contribute to the higher cytotoxicity of SWCNT in this study. The interaction between the SWCNTs and A3 lymphocytes was also observed by scanning electron microscopy. The mechanism for causing cell death in this study was attributed to apoptosis and necrosis after physical penetration by CNTs and oxidative stress via formation of reactive oxygen species.

  20. In vitro evaluation of cytotoxicity of engineered carbon nanotubes in selected human cell lines

    International Nuclear Information System (INIS)

    In this study, we used a systematic approach to study and compare the in vitro cytotoxicity of selected engineered carbon nanotubes (CNTs) to test cell lines including human skin keratinocytes, lung cells and lymphocytes. Results of fluorescein diacetate (FDA) uptake in T4 lymphocyte A3 cells indicated cytotoxicity caused by single-walled carbon nanotubes (SWCNTs) at concentrations of 2, 5 and 10 ppm. At 2 ppm, the SWCNT treatment group retained 71.3% viability compared to the PBS control group. At 10 ppm, cellular viability further decreased to 56.5% of the PBS control group. In the skin keratinocyte HaCaT cells and lung MSTO-211H cells, the SWCNT did not demonstrate any cytotoxicity at concentrations of 2 and 5 ppm but slightly inhibited HaCaT cells and caused significant toxicity to MSTO-211H cells at 10 ppm. Multi-walled carbon nanotube (MWCNT) testing showed significant cytotoxicity to A3 cells in a dose-dependent manner. At 10 ppm the viability of the cells decreased to 89.1% compared to the PBS control. In MSTO-211H cells, MWCNT caused significant toxicity at concentrations of 2 ppm and higher. By comparison, HaCaT cells were inhibited significantly only at 10 ppm. Overall, the test CNTs inhibited cellular viabilities in a concentration, cell type, and CNT type-dependent pattern. The viabilities of the MWCNT-impacted cells are higher than the corresponding SWCNT groups. We speculate that on a per volume basis, the greater availability of defects and contaminants for cellular interaction may contribute to the higher cytotoxicity of SWCNT in this study. The interaction between the SWCNTs and A3 lymphocytes was also observed by scanning electron microscopy. The mechanism for causing cell death in this study was attributed to apoptosis and necrosis after physical penetration by CNTs and oxidative stress via formation of reactive oxygen species.

  1. Activating Transcription Factor 3 regulates in part the enhanced tumour cell cytotoxicity of the histone deacetylase inhibitor M344 and cisplatin in combination

    Directory of Open Access Journals (Sweden)

    St Germain Carly

    2010-09-01

    Full Text Available Abstract Background Activating Transcription Factor (ATF 3 is a key regulator of the cellular integrated stress response whose expression has also been correlated with pro-apoptotic activities in tumour cell models. Combination treatments with chemotherapeutic drugs, such as cisplatin, and histone deacetylase (HDAC inhibitors have been demonstrated to enhance tumour cell cytotoxicity. We recently demonstrated a role for ATF3 in regulating cisplatin-induced apoptosis and others have shown that HDAC inhibition can also induce cellular stress. In this study, we evaluated the role of ATF3 in regulating the co-operative cytotoxicity of cisplatin in combination with an HDAC inhibitor. Results The HDAC inhibitor M344 induced ATF3 expression at the protein and mRNA level in a panel of human derived cancer cell lines as determined by Western blot and quantitative RT-PCR analyses. Combination treatment with M344 and cisplatin lead to increased induction of ATF3 compared with cisplatin alone. Utilizing the MTT cell viability assay, M344 treatments also enhanced the cytotoxic effects of cisplatin in these cancer cell lines. The mechanism of ATF3 induction by M344 was found to be independent of MAPKinase pathways and dependent on ATF4, a known regulator of ATF3 expression. ATF4 heterozygote (+/- and knock out (-/- mouse embryonic fibroblast (MEF as well as chromatin immunoprecipitation (ChIP assays were utilized in determining the mechanistic induction of ATF3 by M344. We also demonstrated that ATF3 regulates the enhanced cytotoxicity of M344 in combination with cisplatin as evidenced by attenuation of cytotoxicity in shRNAs targeting ATF3 expressing cells. Conclusion This study identifies the pro-apoptotic factor, ATF3 as a novel target of M344, as well as a mediator of the co-operative effects of cisplatin and M344 induced tumour cell cytotoxicity.

  2. Preliminary Study on Cytotoxic Effect of Biodegradation of Magnesium on Cancer Cells

    Institute of Scientific and Technical Information of China (English)

    Yu Zhang; Ling Ren; Mei Li; Xiao Lin; Huafu Zhao; Ke Yang

    2012-01-01

    Biodegradation of magnesium (Mg) based metals in body fluid can lead to a strong alkalinity as well as an increase of Mg2+ concentration in its surrounding environment. In vitro cytotoxic effects of the extracts of pure Mg with and without micro arc oxidation (MAO) coating on osteosarcoma U2-OS cells, a kind of bone cancer cells, were preliminarily studied, independently considering the increase of either alkalinity or Mg2+ concentration. The results indicated that the high alkalinity, i.e., a great increase of pH value, caused by the degradations of Mg with and without MAO coating in the culture medium all showed strong cytotoxic effects on U2-OS cells. However, the increase of Mg2+ concentration had no such cytotoxic effect. This finding may provide an alternative way to cure bone cancers through creating a high alkalinity surrounding the cancer cells.

  3. Cytotoxicity assessment of antibiofouling compounds and by-products in marine bivalve cell cultures.

    Science.gov (United States)

    Domart-Coulon, I; Auzoux-Bordenave, S; Doumenc, D; Khalanski, M

    2000-06-01

    Short-term primary cell cultures were derived from adult marine bivalve tissues: the heart of oyster Crassostrea gigas and the gill of clam Ruditapes decussatus. These cultures were used as experimental in vitro models to assess the acute cytotoxicity of an organic molluscicide, Mexel-432, used in antibiofouling treatments in industrial cooling water systems. A microplate cell viability assay, based on the enzymatic reduction of tetrazolium dye (MTT) in living bivalve cells, was adapted to test the cytotoxicity of this compound: in both in vitro models, toxicity thresholds of Mexel-432 were compared to those determined in vivo with classic acute toxicity tests. The clam gill cell model was also used to assess the cytotoxicity of by-products of chlorination, a major strategy of biofouling control in the marine environment. The applications and limits of these new in vitro models for monitoring aquatic pollutants were discussed, in reference with the standardized Microtox test. PMID:10806375

  4. Cytotoxic activity of coumarins from the fruits of Cnidium monnieri on leukemia cell lines.

    Science.gov (United States)

    Yang, Ling-Ling; Wang, Min-Chieh; Chen, Lih-Geeng; Wang, Ching-Chiung

    2003-12-01

    Cnidii monnieri Fructus [CmF; Cnidium monnieri (L.) Cusson] is used as a tonic agent in traditional Chinese medicine. In a previous Chinese herb-cytotoxicity screening test, the ethanol extract of CmF exhibited strong effects on human leukemia (HL-60), cervical carcinoma (HeLa) and colorectal carcinoma (CoLo 205) cells. Then, the CmF extract was subjected to silica gel column chromatography and recrystallization to give five coumarins: osthol, imperatorin, bergapten, isopimpinellin, and xanthotoxin. Among these compounds, osthol showed the strongest cytotoxic activity on tumor cell lines. The structure-activity relationship established from the results indicated that the prenyl group has an important role in the cytotoxic effects. However, imperatorin showed the highest sensitivity to HL-60 cells and the least cytotoxicity to normal PBMCs. Osthol and imperatorin both caused apoptotic bodies, DNA fragmentation, and enhanced PARP degradation in HL-60 cells by biochemical analysis. These results indicate that osthol and imperatorin can induce apoptosis in HL-60 cells. Therefore, osthol and imperatorin are cytotoxic marker substances in the fruits of Cnidium monnieri. PMID:14750023

  5. Cytotoxicity Effects of Amoora rohituka and chittagonga on Breast and Pancreatic Cancer Cells

    Directory of Open Access Journals (Sweden)

    Leo L. Chan

    2011-01-01

    Full Text Available Chemotherapeutic agents for cancer are highly toxic to healthy tissues and hence alternative medicine avenues are widely researched. Majority of the recent studies on alternative medicine suggested that Amoora rohituka possesses considerable antitumor and antibacterial properties. In this work, rohituka and chittagonga, fractionated with petroleum ether, dichloromethane, and ethanol, were explored for their anticancer potential against two breast cancer (MCF-7 and HTB-126 and three pancreatic cancer (Panc-1, Mia-Paca2, and Capan1. The human foreskin fibroblast, Hs68, was also included. Cytotoxicity of each extract was analyzed using the MTT assay and label-free photonic crystal biosensor assay. A concentration series of each extract was performed on the six cell lines. For MCF-7 cancer cells, the chittagonga (Pet-Ether and CH2Cl2 and rohituka (Pet-Ether extracts induced cytotoxicity; the chittagonga (EtoAC and rohituka (MeOH extracts did not induce cytotoxicity. For HTB126, Panc-1, Mia-Paca2, and Capan-1 cancer cells, only the chittagonga CH2Cl2 extract showed a significant cytotoxic effect. The extracts were not cytotoxic to normal fibroblast Hs68 cells, which may be correlated to the specificity of Amoora extracts in targeting cancerous cells. Based on these results, further examination of the potential anticancer properties Amoora species and the identification of the active ingredients of these extracts is warranted.

  6. DMSO exhibits similar cytotoxicity effects to thalidomide in mouse breast cancer cells

    OpenAIRE

    Öz, Ece Simsek; Aydemir, Esra; Fışkın, Kayahan

    2012-01-01

    The purpose of this study was to evaluate the cytotoxic effect of thalidomide on 4T1 and 4THMpc mouse breast cancer cell lines. Mouse breast cancer cells (4T1) and cells derived from metastatic lesions (4THMpc) were treated with various doses of thalidomide [10-2-100 µM dissolved in dimethyl sulfoxide (DMSO) as recommended] and 1.4 µM DMSO (maximum DMSO concentration in the highest thalidomide dose) as a DMSO control against the untreated control groups. MTT was used to evaluate the cytotoxic...

  7. Cytotoxic activity of labdane type diterpenes against human leukemic cell lines in vitro.

    Science.gov (United States)

    Dimas, K; Demetzos, C; Marsellos, M; Sotiriadou, R; Malamas, M; Kokkinopoulos, D

    1998-04-01

    Nine labdane type diterpenes isolated from the plant Cistus creticus subsp. creticus and from the resin "Ladano" which is excreted on the surface of the leaves and stems of this plant, were examined for their in vitro cytotoxic activity against 14 human leukemic cell lines. Compound 1, (13E)-labd-13-ene-8 alpha,15-diol, exhibited cytotoxic activity against 13 of the cell lines tested, while compound 2, (13E)-labd-7,13-dienol, was active only against HL60 cells. Further compound 1 was examined for its effect on the uptake of [3H]-thymidine as a marker of DNA synthesis. PMID:9581515

  8. Cell-mediated immune responses in rainbow trout after DNA immunization against the viral hemorrhagic septicemia virus

    DEFF Research Database (Denmark)

    Utke, Katrin; Kock, Holger; Schuetze, Heike; Bergmann, Sven M.; Lorenzen, Niels; Einer-Jensen, Katja; Köllner, Bernd; Dalmo, Roy A.; Vesely, Tomas; Ototake, Mitsuru; Fischer, Uwe

    2008-01-01

    To identify viral proteins that induce cell-mediated cytotoxicity (CMC) against viral hemorrhagic septicemia virus (VHSV)-infected cells, rainbow trout were immunized with DNA vectors encoding the glycoprotein G or the nucleocapsid protein N of VHSV. The G protein was a more potent trigger of...

  9. Cytotoxic effects of new MTA-based cement formulations on fibroblast-like MDPL-20 cells

    Directory of Open Access Journals (Sweden)

    Lucas da Fonseca Roberti GARCIA

    2016-01-01

    Full Text Available Abstract The present study aimed at evaluating the cytotoxic effects of a novel cement called CER on periodontal fibroblast-like cells of mice (MDPL-20, in comparison with different formulations of Mineral Trioxide Aggregate (MTA, by means of the cell viability test (MTT and cell morphology analysis. Thirty-two round-shaped samples were fabricated with the following cements: white MTA, white and gray CER and experimental white MTA. The samples were immersed in serum-free culture medium for 24 hours or 7 days (n = 16. The extracts (culture medium + components released from the cements were applied for 24 hours to previously cultured cells (40.000 cells/cm2 in the wells of 24-well plates. Cells seeded in complete culture medium were used as a negative control. Cell viability was assessed using the MTT assay. Two samples of each cement were used for cell morphology analysis by Scanning Electron Microscopy (SEM. The extracts obtained at the 7-day period presented higher cytotoxicity compared with the 24-hour period (p 0.05. However, at the 7-day period, the experimental white MTA presented no significant difference in comparison with the other cements (p > 0.05. At the 7-day period, CER cement presented cytotoxic effects on fibroblast-like cells, similar to different MTA formulations. However, the immersion period in the culture medium influenced the cytotoxicity of the cements, which was greater for CER cement at 24 hours.

  10. In vitro cytotoxicity of Indonesian stingless bee products against human cancer cell lines

    Institute of Scientific and Technical Information of China (English)

    Paula M Kustiawan; Songchan Puthong; Enos T Arung; Chanpen Chanchao

    2014-01-01

    Objective: To screen crude extracts of propolis, bee pollen and honey from four stingless bee species [Trigona incisa (T. incisa)], Timia apicalis, Trigona fusco-balteata and Trigona fuscibasis) native to East Kalimantan, Indonesia for cytotoxic activity against five human cancer cell lines (HepG2, SW620, ChaGo-I, KATO-III and BT474).Methods:All samples were extracted with methanol, and then subpartitioned with n-hexane and ethyl acetate. Each crude extract was screened at 20 µg/mL for in vitro cytotoxicity against the cell lines using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. In addition, four previously shown bioactive components from propolis (apigenin, caffeic acid phenyl ester, kaempferol and naringenin) and two chemotherapeutic drugs (doxorubicin and 5-fluorouracil) were used to evaluate the sensitivity of the cell lines.Results:Overall, crude extracts from propolis and honey had higher cytotoxic activities than bee pollen, but the activity was dependent upon the extraction solvent, bee species and cell line. Propolis extracts from T. incisa and Timia apicalis showed the highest and lowest cytotoxic activity, respectively. Only the HepG2 cell line was broadly sensitive to the honey extracts. For pure compounds, doxorubicin was the most cytotoxic, the four propolis compounds the least, but the ChaGo-I cell line was sensitive to kaempferol at 10 µg/mL and KATO-III was sensitive to kaempferol and apigenin at 10 µg/mL. All pure compounds were effective against the BT474 cell line.Conclusions:Propolis from T. incisa and Trigona fusco-balteata contain an in vitro cytotoxic activity against human cancer cell lines. Further study is required, including the isolation and characterization of the active antiproliferative agent(s).

  11. Cytotoxicity of clove (Syzygium aromaticum) oil and its major components to human skin cells.

    Science.gov (United States)

    Prashar, A; Locke, I C; Evans, C S

    2006-08-01

    The essential oil extracted from clove (Syzygium aromaticum) is used as a topical application to relieve pain and promote healing in herbal medicine and also finds use in the fragrance and flavouring industries. Clove oil has two major components, eugenol and beta-caryophyllene, which constitute 78% and 13% of the oil, respectively. Clove oil and these components are generally recognized as 'safe', but the in-vitro study here demonstrates cytotoxic properties of both the oil and eugenol, towards human fibroblasts and endothelial cells. Clove oil was found to be highly cytotoxic at concentrations as low as 0.03% (v/v) with up to 73% of this effect attributable to eugenol. beta-caryophyllene did not exhibit any cytotoxic activity, indicating that other cytotoxic components may also exist within the parent oil. PMID:16872360

  12. Cytotoxicity and genotoxicity assessment of Euphorbia hirta in MCF-7 cell line model using comet assay

    Institute of Scientific and Technical Information of China (English)

    Kwan Yuet Ping; Ibrahim Darah; Yeng Chen; Sreenivasan Sasidharan

    2013-01-01

    Objective:To evaluate the cytotoxicity and genotoxicity activity of Euphorbia hirta (E. hirta) in MCF-7 cell line model using comet assay. Methods: The cytotoxicity of E. hirta extract was investigated by employing brine shrimp lethality assay and the genotoxicity of E. hirta was assessed by using Comet assay. Results: Both toxicity tests exhibited significant toxicity result. In the comet assay, the E. hirta extract exhibited genotoxicity effects against MCF-7 DNA in a time-dependent manner by increasing mean percentage of DNA damage. The extract of E. hirta showed significant toxicity against brine shrimp with an LC50 value of 620.382 μg/mL (24 h). Comparison with positive control potassium dichromate signifies that cytotoxicity exhibited by the methanol extract might have moderate activity. Conclusion:The present work confirmed the cytotoxicity and genotoxicity of E. hirta. However, the observed toxicity of E. hirta extracts needs to be confirmed in additional studies.

  13. Generation of MHC class I-restricted cytotoxic T cell lines and clones against colonic epithelial cells from ulcerative colitis.

    Science.gov (United States)

    Yonamine, Y; Watanabe, M; Kinjo, F; Hibi, T

    1999-01-01

    We established CTL lines and clones against colonic epithelial cells from PBLs of patients with ulcerative colitis by continuous stimulation with HLA-A locus-matched colonic epithelial cell lines. We developed a nonradioactive europium release cytotoxicity assay to detect CTLs. PBLs from 3 of 12 patients but not from any of 14 normal controls who shared at least one haplotype of HLA-A locus with two colonic epithelial cell lines, CW2 and ACM, showed increased cytotoxicity against these lines. Three CTL lines established from the PBLs of patients showed increased cytotoxicity against HLA-A locus-matched CW2 or ACM but not against matched lung or esophagus cell lines. The phenotypes of CTL lines were alpha beta-TCR+ CD3+ CD8+ CD16-. The CTL line MS showed increased cytotoxicity against freshly isolated colonic epithelial cells but not against cells with a different HLA-A locus. Two CTL clones were generated from MS and clone 3-2, expressing CD3+ CD8+ CD4- CD56-, showed high MHC class I-restricted cytotoxicity against the colonic epithelial cells. These results indicated that CTLs against colonic epithelial cells may contribute to epithelial cell damage in ulcerative colitis. PMID:10080107

  14. Role of quercetin on Caco-2 cells against cytotoxic effects of alternariol and alternariol monomethyl ether.

    Science.gov (United States)

    Fernández-Blanco, Celia; Font, Guillermina; Ruiz, Maria-Jose

    2016-03-01

    Molds of the genus Alternaria have been reported as contaminants of a variety of food and feed. Alternaria toxins such as alternariol (AOH) and its naturally occurring monomethyl ether (AME) produce cytotoxicity and oxidative stress in cell cultures. On the other hand, it has been proved that natural polyphenols have antioxidant effect. Quercetin (Quer) is a polyphenol present in berries and other commodities which exhibits these effects. The aims were to evaluate the cytotoxicity of AOH, AME and the binary combination of them, and the cytoprotective effect of Quer exposed simultaneously with AOH, AME and the mycotoxin mixture in human adenocarcinoma (Caco-2) cells. The cytotoxicity and the cytoprotective effect were determined by the MTT test after 24 and 48 h of exposure and interactions were evaluated with the isobologram analysis method. Cell viability decreased after 48 h of AOH and AME exposures, being the binary combination more cytotoxic, causing a synergism effect. No cytoprotective effect of Quer against AOH and AME was observed when they were exposed simultaneously in Caco-2 cells. The cytoprotective effect of Quer against mycotoxins (AOH, AME or other different which could present higher cytotoxic effect) depends on the concentration, the presence and the interaction between the compounds in food. PMID:26802676

  15. Effects of spider Macrothele raven venom on cell proliferation and cytotoxicity in HeLa cells

    Institute of Scientific and Technical Information of China (English)

    Li GAO; Bao-en SHAN; Jing CHEN; Jiang-hui LIU; Da-xiang SONG; Bao-cheng ZHU

    2005-01-01

    Aim: To examine the effect of venom from the spider Macrothele raven on cell proliferation and cytotoxicity in human cervical carcinoma, HeLa cells. Methods:Morphological and biochemical signs of apoptosis appeared using acridine orange-ethidium bromide (AO/EB) staining. Marked morphological changes in HeLa cells after treatment with spider venom were observed using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Cell proliferation and cytotoxicity were determined by [methyl-3H] thymidine assay ([3H]TdR) and lactate dehydrogenase (LDH) release, respectively. DNA fragmentation and cell cycle distribution were monitored using flow cytometry. In addition, Western blot analysis was used to evaluate the level of caspase-3 expression. In vivo examination of the inhibition of the size of tumors in nude mice treated with spider venom was measured. Results: Marked morphological changes were observed using AO/EB staining, SEM and TEM assay. Spider venom at concentrations of 10-40 mg/L caused dose- and time-dependent inhibition of HeLa cell proliferation.The ratio of apoptosis and necrosis increased. The activity of caspase-3 was upregulated after spider venom treatment. In vivo study of tumor size revealed that tumors significantly decreased in size from controls to tumors treated for 3 weeks with spider venom (P<0.05). Conclusion: The inhibition of HeLa cells by the venom of the spider Macrothele raveni was carried out in three ways: induction of apoptosis, necrosis of toxicity damage and direct lysis. Spider venom is a novel anti-tumor material both in vitro and in vivo.

  16. Postincubation with aclarubicin reverses topoisomerase II mediated DNA cleavage, strand breaks, and cytotoxicity induced by VP-16

    DEFF Research Database (Denmark)

    Petersen, L N; Jensen, P B; Sørensen, B S; Engelholm, S A; Spang-Thomsen, M

    1994-01-01

    In previous studies, we found that VP-16 (etoposide) induced cytotoxicity and protein-concealed strand break formation was prevented in a small cell lung cancer (SCLC) cell line, when the cells were incubated with aclarubicin prior to treatment with VP-16. In the present work, we studied the effe...... the antagonism to topo-II targeting drugs both when administered prior to and after the topo-II targeting agents. Thus, our data suggest that sequential rather than simultaneous administration of aclarubicin and topo-II targeting agents may be superior with respect to net...

  17. A distinct subset of self-renewing human memory CD8+ T cells survives cytotoxic chemotherapy

    OpenAIRE

    Turtle, Cameron J.; Swanson, Hillary M.; Fujii, Nobuharu; Estey, Elihu H.; Riddell, Stanley R.

    2009-01-01

    The mechanisms that maintain human T cell memory during normal and perturbed homeostasis are not fully understood. The repeated induction of profound lymphocytopenia in patients undergoing multiple cycles of cytotoxic chemotherapy infrequently results in severe infections with viruses controlled by memory T cells, suggesting that some memory T cells survive chemotherapy and restore immunity. Here we identify a distinct subpopulation of memory CD8+ T cells with the ability to rapidly efflux an...

  18. Poly (D,L-lactide-co-glycolide nanoparticles: Uptake by epithelial cells and cytotoxicity

    Directory of Open Access Journals (Sweden)

    J. H. Hamman

    2014-03-01

    Full Text Available Nanoparticles as drug delivery systems offer benefits such as protection of the encapsulated drug against degradation, site-specific targeting and prolonged blood circulation times. The aim of this study was to investigate nanoparticle uptake into Caco-2 cell monolayers, their co-localization within the lysosomal compartment and their cytotoxicity in different cell lines. Rhodamine-6G labelled poly(D,L-lactide-co-glycolide (PLGA nanoparticles were prepared by a double emulsion solvent evaporation freeze-drying method. Uptake and co-localisation of PLGA nanoparticles in lysosomes were visualized by confocal laser scanning microscopy. The cytotoxicity of the nanoparticles was evaluated on different mammalian cells lines by means of Trypan blue exclusion and the MTS assay. The PLGA nanoparticles accumulated in the intercellular spaces of Caco-2 cell monolayers, but were also taken up transcellularly into the Caco-2 cells and partially co-localized within the lysosomal compartment indicating involvement of endocytosis during uptake. PLGA nanoparticles did not show cytotoxic effects in all three cell lines. Intact PLGA nanoparticles are therefore capable of moving across epithelial cell membranes partly by means of endocytosis without causing cytotoxic effects.

  19. Increased betulinic acid induced cytotoxicity and radiosensitivity in glioma cells under hypoxic conditions

    Directory of Open Access Journals (Sweden)

    Paschke Reinhard

    2011-09-01

    Full Text Available Abstract Background Betulinic acid (BA is a novel antineoplastic agent under evaluation for tumor therapy. Because of the selective cytotoxic effects of BA in tumor cells (including gliomas, the combination of this agent with conservative therapies (such as radiotherapy and chemotherapy may be useful. Previously, the combination of BA with irradiation under hypoxic conditions had never been studied. Methods In this study, the effects of 3 to 30 μM BA on cytotoxicity, migration, the protein expression of PARP, survivin and HIF-1α, as well as radiosensitivity under normoxic and hypoxic conditions were analyzed in the human malignant glioma cell lines U251MG and U343MG. Cytotoxicity and radiosensitivity were analyzed with clonogenic survival assays, migration was analyzed with Boyden chamber assays (or scratch assays and protein expression was examined with Western blot analyses. Results Under normoxic conditions, a half maximal inhibitory concentration (IC50 of 23 μM was observed in U251MG cells and 24 μM was observed in U343MG cells. Under hypoxic conditions, 10 μM or 15 μM of BA showed a significantly increased cytotoxicity in U251MG cells (p = 0.004 and p = 0.01, respectively and U343MG cells (p Conclusion Our results suggest that BA is capable of improving the effects of tumor therapy in human malignant glioma cells, particularly under hypoxic conditions. Further investigations are necessary to characterize its potential as a radiosensitizer.

  20. Chemical dispersants used in the Gulf of Mexico oil crisis are cytotoxic and genotoxic to sperm whale skin cells.

    Science.gov (United States)

    Wise, Catherine F; Wise, James T F; Wise, Sandra S; Thompson, W Douglas; Wise, John Pierce; Wise, John Pierce

    2014-07-01

    The 2010 Deepwater Horizon oil rig explosion in the Gulf of Mexico drew attention to the need for toxicological studies of chemical dispersants. We are still learning the effects these spills had on wildlife. Little is known about the toxicity of these substances in marine mammals. The objective of this study was to determine the toxicity of the two dispersants (Corexit 9500 and 9527). Corexit 9500 and 9527 were both cytotoxic to sperm whale skin fibroblasts. Corexit 9527 was less cytotoxic than 9500. S9 mediated metabolism did not alter cytotoxicity of either dispersant. Both dispersants were genotoxic to sperm whale skin fibroblasts; S9 mediated metabolism increased Corexit 9527 genotoxicity. PMID:24813266

  1. Cytotoxic T lymphocyte control during ectromelia (mousepox) virus infection: Interaction between MHC-restricted cells analyzed by non-radioactive-fluorimetry

    International Nuclear Information System (INIS)

    Cytotoxic T lymphocyte activity of draining lymph node cells isolated from BALB/c mice infected with ectromelia virus (EV) was examined using a fluorometric cell-mediated cytotoxicity (CMC) assay. Specific lysis of target cells A20 and EMT-6 primed with EV was demonstrated. The classical CD8+ cytolytic pathway (72.7%) as compared to that of CD4+ (27.3%) in the cellular response during acute infection. Also an alternative method for determining CMC, employing a bis-benzamide dye for labelling target cells, is described. Coefficient variations of relative fluorescence were below 6%, that makes the method sensitive and reliable. Comparison of the assay demonstrated with to that of the 51Cr-release assay is discussed

  2. Metabolic basis of ethanol-induced cytotoxicity in recombinant HepG2 cells: Role of nonoxidative metabolism

    International Nuclear Information System (INIS)

    Chronic alcohol abuse, a major health problem, causes liver and pancreatic diseases and is known to impair hepatic alcohol dehydrogenase (ADH). Hepatic ADH-catalyzed oxidation of ethanol is a major pathway for the ethanol disposition in the body. Hepatic microsomal cytochrome P450 (CYP2E1), induced in chronic alcohol abuse, is also reported to oxidize ethanol. However, impaired hepatic ADH activity in a rat model is known to facilitate a nonoxidative metabolism resulting in formation of nonoxidative metabolites of ethanol such as fatty acid ethyl esters (FAEEs) via a nonoxidative pathway catalyzed by FAEE synthase. Therefore, the metabolic basis of ethanol-induced cytotoxicity was determined in HepG2 cells and recombinant HepG2 cells transfected with ADH (VA-13), CYP2E1 (E47) or ADH + CYP2E1 (VL-17A). Western blot analysis shows ADH deficiency in HepG2 and E47 cells, compared to ADH-overexpressed VA-13 and VL-17A cells. Attached HepG2 cells and the recombinant cells were incubated with ethanol, and nonoxidative metabolism of ethanol was determined by measuring the formation of FAEEs. Significantly higher levels of FAEEs were synthesized in HepG2 and E47 cells than in VA-13 and VL-17A cells at all concentrations of ethanol (100-800 mg%) incubated for 6 h (optimal time for the synthesis of FAEEs) in cell culture. These results suggest that ADH-catalyzed oxidative metabolism of ethanol is the major mechanism of its disposition, regardless of CYP2E1 overexpression. On the other hand, diminished ADH activity facilitates nonoxidative metabolism of ethanol to FAEEs as found in E47 cells, regardless of CYP2E1 overexpression. Therefore, CYP2E1-mediated oxidation of ethanol could be a minor mechanism of ethanol disposition. Further studies conducted only in HepG2 and VA-13 cells showed lower ethanol disposition and ATP concentration and higher accumulation of neutral lipids and cytotoxicity (apoptosis) in HepG2 cells than in VA-13 cells. The apoptosis observed in HepG2 vs

  3. Vorinostat Enhances Cytotoxicity of SN-38 and Temozolomide in Ewing Sarcoma Cells and Activates STAT3/AKT/MAPK Pathways.

    Directory of Open Access Journals (Sweden)

    Valerie B Sampson

    Full Text Available Histone deacetylase inhibitors (HDACi have been evaluated in patients with Ewing sarcoma (EWS but demonstrated limited activity. To better understand the potential for HDACi in EWS, we evaluated the combination of the HDACi vorinostat, with DNA damaging agents SN-38 (the active metabolite of irinotecan and topoisomerase 1 inhibitor plus the alkylating agent temozolomide (ST. Drugs were evaluated in sequential and simultaneous combinations in two EWS cell lines. Results demonstrate that cell viability, DNA damage and reactive oxygen species (ROS production are dependent on the sequence of drug administration. Enhanced cytotoxicity is exhibited in vitro in EWS cell lines treated with ST administered before vorinostat, which was modestly higher than concomitant treatment and superior to vorinostat administered before ST. Drug combinations downregulate cyclin D1 to induce G0/G1 arrest and promote apoptosis by cleavage of caspase-3 and PARP. When ST is administered before or concomitantly with vorinostat there is activation of STAT3, MAPK and the p53 pathway. In contrast, when vorinostat is administered before ST, there is DNA repair, increased AKT phosphorylation and reduced H2B acetylation. Inhibition of AKT using the small molecule inhibitor MK-2206 did not restore H2B acetylation. Combining ST with the dual ALK and IGF-1R inhibitor, AZD3463 simultaneously inhibited STAT3 and AKT to enhance the cytotoxic effects of ST and further reduce cell growth suggesting that STAT3 and AKT activation were in part mediated by ALK and IGF-1R signaling. In summary, potent antiproliferative and proapoptotic activity were demonstrated for ST induced DNA damage before or simultaneous with HDAC inhibition and cell death was mediated through the p53 pathway. These observations may aid in designing new protocols for treating pediatric patients with high-risk EWS.

  4. Indoleamine 2,3-dioxygenase specific, cytotoxic T cells as immune regulators

    DEFF Research Database (Denmark)

    Sørensen, Rikke Bæk; Hadrup, Sine Reker; Svane, Inge Marie; Hjortso, Mads Christian; Straten, Per Thor; Andersen, Mads Hald

    2011-01-01

    Indoleamine 2,3-dioxygenase (IDO) is an immunoregulatory enzyme that is implicated in suppressing T-cell immunity in normal and pathologic settings. Here, we describe that spontaneous cytotoxic T-cell reactivity against IDO exists not only in patients with cancer but also in healthy persons. We...... caused an increase in the production of the proinflammatory cytokines IL-6 and tumor necrosis factor-alpha while decreasing the IL-10 production. Finally, the addition of IDO-inducing agents (ie, the TLR9 ligand cytosine-phosphate- guanosine, soluble cytotoxic T lymphocyte-associated antigen 4, or...

  5. Screening ToxCast™ Phase I Chemicals in a Mouse Embryonic Stem Cell Adherent Cell Differentiation and Cytotoxicity (ACDC) Assay

    Science.gov (United States)

    An Adherent Cell Differentiation and Cytotoxicity (ACDC) in vitro assay with mouse embryonic stem cells was used to screen the ToxCast Phase I chemical library for effects on cellular differentiation and cell number. The U.S. Environmental Protection Agency (EPA) established the ...

  6. Helicobacter pylori infection in a pig model is dominated by Th1 and cytotoxic CD8+ T cell responses.

    Science.gov (United States)

    Kronsteiner, Barbara; Bassaganya-Riera, Josep; Philipson, Casandra; Viladomiu, Monica; Carbo, Adria; Pedragosa, Mireia; Vento, Salvador; Hontecillas, Raquel

    2013-10-01

    Helicobacter pylori infection is the leading cause for peptic ulcer disease and gastric adenocarcinoma. Mucosal T cell responses play an important role in mediating H. pylori-related gastric immunopathology. While induced regulatory T (iTreg) cells are required for chronic colonization without disease, T helper 1 (Th1) effector responses are associated with lower bacterial loads at the expense of gastric pathology. Pigs were inoculated with either H. pylori strain SS1 or J99. Phenotypic and functional changes in peripheral blood mononuclear cell (PBMC) populations were monitored weekly, and mucosal immune responses and bacterial loads were assessed up to 2 months postinfection. Both H. pylori strains elicited a Th1 response characterized by increased percentages of CD4(+)Tbet(+) cells and elevated gamma interferon (IFN-γ) mRNA in PBMCs. A subset of CD8(+) T cells expressing Tbet and CD16 increased following infection. Moreover, a significant increase in perforin and granzyme mRNA expression was observed in PBMCs of infected pigs, indicating a predominant cytotoxic immune response. Infiltration of B cells, myeloid cells, T cells expressing Treg- and Th17-associated transcription factors, and cytotoxic T cells was found in the gastric lamina propria of both infected groups. Interestingly, based on bacterial reisolation data, strain SS1 showed greater capacity to colonize and/or persist in the gastric mucosa than did strain J99. This novel pig model of infection closely mimics human gastric pathology and presents a suitable avenue for studying effector and regulatory responses toward H. pylori described in humans. PMID:23897614

  7. Synthesis and cytotoxicity evaluation of 4-amino-4-dehydroxylarctigenin derivatives in glucose-starved A549 tumor cells.

    Science.gov (United States)

    Lei, Min; Gan, Xianwen; Zhao, Kun; Yu, Qiang; Hu, Lihong

    2015-02-01

    The natural product arctigenin (ATG) demonstrated preferential cytotoxicity to cancer cells under glucose starvation. A series of 4-amino-4-dehydroxylarctigenin derivatives based on lead compound ATG were designed and synthesized by bioisosteric modifications. Their cytotoxicities were evaluated in glucose-starved A549 tumor cells and the results indicated that the 4-amino-4-dehydroxylarctigenin showed more potent cytotoxicity than arctigenin, and the further substituent group on 4-amino would result in the cytotoxicities decreased significantly. 4-Substituted-arctigenin could selectively target on glucose-starved A549 tumor cells which provide an alternative strategy for anticancer drug development with minimal normal tissue toxicity. PMID:25571795

  8. Cytotoxicity evaluation of carbon-encapsulated iron nanoparticles in melanoma cells and dermal fibroblasts

    Energy Technology Data Exchange (ETDEWEB)

    Grudzinski, Ireneusz P., E-mail: ireneusz.grudzinski@wum.edu.pl [Medical University of Warsaw, Department of Toxicology, Faculty of Pharmacy (Poland); Bystrzejewski, Michal [Warsaw University, Department of Physical Chemistry, Faculty of Chemistry (Poland); Cywinska, Monika A.; Kosmider, Anita [Medical University of Warsaw, Department of Toxicology, Faculty of Pharmacy (Poland); Poplawska, Magdalena [Warsaw University of Technology, Department of Organic Chemistry, Faculty of Chemistry (Poland); Cieszanowski, Andrzej [Medical University of Warsaw, Department of Clinical Radiology, Faculty of Medicine (Poland); Ostrowska, Agnieszka [Analytic Centre, University of Life Sciences SGGW (Poland)

    2013-08-15

    Carbon-encapsulated iron nanoparticles (CEINs) are emerging as promising biomedical tools due to their unique physicochemical properties. In this study, the cytotoxic effect of CEINs (the mean diameter distribution ranges 46-56 nm) has been explored by MTT, LDH leakage, Calcein-AM/propidium iodide (PI) and Annexin V-FITC/PI assays in human melanoma (HTB-140), mouse melanoma (B16-F10) cells, and human dermal fibroblasts (HDFs). The results demonstrated that CEINs produce mitochondrial and cell membrane cytotoxicities in a dose (0.0001-100 {mu}g/ml)-dependent manner. Moreover, the studies elucidated some differences in cytotoxic effects between CEINs used as raw and purified materials composing of the carbon surface with acidic groups. Experiments showed that HTB-140 cells are more sensitive to prone early apoptotic events due to raw CEINs as compared to B16-F10 or HDF cells, respectively. Taken together, these results suggest that the amount of CEINs administered to cells and the composition of CEINs containing different amounts of iron as well as the carbon surface modification type is critical determinant of cytotoxic responses in both normal and cancer (melanoma) cells.

  9. T-2 toxin-induced cytotoxicity and damage on TM3 Leydig cells.

    Science.gov (United States)

    Yuan, Zhihang; Matias, Froilan Bernard; Yi, Jin-E; Wu, Jing

    2016-01-01

    T-2 toxin is a highly toxic mycotoxin produced by various Fusarium species, mainly, Fusarium sporotrichoides, and has been reported to have toxic effects on reproductive system of adult male animals. This study investigated the dose-dependent cytotoxicity of T-2 toxin on reproductive cells using TM3 Leydig cells. Specifically, the cytotoxic effect of T-2 toxin was assessed by measuring cell viability; lactate dehydrogenase (LDH); malondialdehyde (MDA); antioxidant activity by measuring superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-PX), and DNA damage; and cell apoptosis. Results showed that T-2 toxin is highly cytotoxic on TM3 Leydig cells. However, Trolox-treated TM3 Leydig cells showed significantly reduced oxidative damage, DNA damage, and apoptosis induced by T-2 toxin. This study proves that T-2 toxin can damage the testes and thus affects the reproductive capacity of animals and humans. Furthermore, oxidative stress plays an important role in the cytotoxic effect of T-2 toxin. PMID:26707243

  10. Cytotoxic Effects of Hydroxylated Fullerenes in Three Types of Liver Cells

    Directory of Open Access Journals (Sweden)

    Yoshiaki Ikarashi

    2013-07-01

    Full Text Available Fullerenes C60 have attracted considerable attention in the biomedical field due to their interesting properties. Although there has been a concern that C60 could be metabolized to hydroxylated fullerenes (C60(OHx in vivo, there is little information on the effect of hydroxylated C60 on liver cells. In the present study, we evaluated the cytotoxic effects of fullerene C60 and various hydroxylated C60 derivatives, C60(OH2, C60(OH6–12, C60(OH12 and C60(OH36, with three different types of liver cells, dRLh-84, HepG2 and primary cultured rat hepatocytes. C60, C60(OH2 and C60(OH36 exhibited little or no cytotoxicity in all of the cell types, while C60(OH6–12 and C60(OH12 induced cytotoxic effects in dRLh-84 cells, accompanied by the appearance of numerous vacuoles around the nucleus. Moreover, mitochondrial activity in liver cells was significantly inhibited by C60(OH6–12 and C60(OH12. These results indicate that the number of hydroxyl groups on C60(OHx contribute to the difference of their cytotoxic potential and mitochondrial damage in liver cells.

  11. Cytotoxicity evaluation of carbon-encapsulated iron nanoparticles in melanoma cells and dermal fibroblasts

    International Nuclear Information System (INIS)

    Carbon-encapsulated iron nanoparticles (CEINs) are emerging as promising biomedical tools due to their unique physicochemical properties. In this study, the cytotoxic effect of CEINs (the mean diameter distribution ranges 46–56 nm) has been explored by MTT, LDH leakage, Calcein-AM/propidium iodide (PI) and Annexin V-FITC/PI assays in human melanoma (HTB-140), mouse melanoma (B16-F10) cells, and human dermal fibroblasts (HDFs). The results demonstrated that CEINs produce mitochondrial and cell membrane cytotoxicities in a dose (0.0001–100 μg/ml)-dependent manner. Moreover, the studies elucidated some differences in cytotoxic effects between CEINs used as raw and purified materials composing of the carbon surface with acidic groups. Experiments showed that HTB-140 cells are more sensitive to prone early apoptotic events due to raw CEINs as compared to B16-F10 or HDF cells, respectively. Taken together, these results suggest that the amount of CEINs administered to cells and the composition of CEINs containing different amounts of iron as well as the carbon surface modification type is critical determinant of cytotoxic responses in both normal and cancer (melanoma) cells

  12. Dynamics of mercury, cadmium and vanadium in cultured bovine kidney cells: an examination of relationships to cytotoxicity and cell function

    International Nuclear Information System (INIS)

    The objective of this study was to partially define the in vitro cellular response to mercury, cadmium and vanadium insult. A bovine kidney cell line served as the model system for examining the relationship of the cellular dynamics of metal accumulation and distribution to cytotoxicity. Additionally, biochemical marker functions were monitored in surviving cells to determine the importance of metal uptake and distribution to cell functionality. Each metal (HgCl2, CdCl2, and Na3VO4) elicited a concentration-related cytotoxicity which was correlated to the cellular metal burden. Multiphasic accumulation kinetics were established for mercury and vanadium; cadmium was accumulated in a linear fashion. Subcellular metal distribution was independent of both the extra-cellular metal concentration and the degree of cytotoxicity. Biochemical marker functions indicated a toxicity-related decrease in cell functionality in surviving cells for all metals

  13. Physicochemical characteristics and bronchial epithelial cell cytotoxicity of Folpan 80 WG® and Myco 500®, two commercial forms of folpet

    Directory of Open Access Journals (Sweden)

    Baldi Isabelle

    2007-09-01

    cytotoxic to respiratory cells in vitro. Folpet particles may mediate its toxicity directly or indirectly through ROS-mediated alterations. These data constitute the first step towards the risk assessment of folpet particles by inhalation for human health. This work confirms the need for further studies on the effect of environmental pesticides on the respiratory system.

  14. Evaluation of Cytotoxicity of Sagebrush Plain Extract on Human Breast Cancer MCF7 Cells

    Directory of Open Access Journals (Sweden)

    B Gordanian

    2013-07-01

    Full Text Available Abstract Background & aim: Several studies have reported anti-cancer properties of sagebrush plain. The aim of this study was to evaluate the cytotoxicity of the methanol extract of sagebrush plain on human breast cancer MCF7 cells. Methods: In the present experimental study, the toxic effects of methanol extracts of flowers, leaves, stems and roots of sagebrush plain from of Khorassan and Esfahan province were tested on human breast cancer cells MCF-7 and normal cells HEK293 . Plant samples were extracted by methanol and their toxic effects on normal and breast cancer cells at concentrations of 5.62, 125, 250 and 500 µg/ml was determined by MTT. Both breast cancer cells MCF-7 and normal HEK293 cells were cultured in RPMI-1640 medium and DMEM containing 10% fetal calf serums were cultured. Data were analyzed by one-way ANOVA. Results: The methanol extract of sagebrush showed toxicity on MCF7 cells. The extract of Khorasan showed higher toxicity than Esfahan province. IC50 of sagebrush plant for all parts of the plant were obtained more than 500 µg/ml, but the IC50 of sagebrush plant of Khorasan region in leaf and flower were 205 ± 1.3 and 213 ± 5.3µg respectively. The leaves and flowers in both cases had the highest cytotoxicity. Plant extracts in both regions did not show significant cytotoxicity on normal HEK293 cells. Conclusion: The extract of the sagebrush plain region of Khorasan region showed greater cytotoxicity than Esfahan. It seems that different environmental conditionshas considerable cytotoxicity. Keywords: Sagebrush Plain, MTT, Breast Cancer

  15. Synthesis and Selective Cytotoxic Activities on Rhabdomyosarcoma and Noncancerous Cells of Some Heterocyclic Chalcones.

    Science.gov (United States)

    Do, Tuong-Ha; Nguyen, Dai-Minh; Truong, Van-Dat; Do, Thi-Hong-Tuoi; Le, Minh-Tri; Pham, Thanh-Quan; Thai, Khac-Minh; Tran, Thanh-Dao

    2016-01-01

    Chemically diverse heterocyclic chalcones were prepared and evaluated for cytotoxicity, aiming to push forward potency and selectivity. They were tested against rhabdomyosarcoma (RMS) and noncancerous cell line (LLC-PK1). The influence of heteroaryl patterns on rings A and B was studied. Heterocycle functionalities on both rings, such as phenothiazine, thiophene, furan and pyridine were evaluated. Notably, the introduction of three methoxy groups at positions 3, 4, 5 on ring B appears to be critical for cytotoxicity. The best compound, with potent and selective cytotoxicity (IC50 = 12.51 μM in comparison with the value 10.84 μM of paclitaxel), contains a phenothiazine moiety on ring A and a thiophene heterocycle on ring B. Most of the potential compounds only show weak cytoxicity on the noncancerous cell line LLC-PK1. PMID:27005608

  16. Synthesis and Selective Cytotoxic Activities on Rhabdomyosarcoma and Noncancerous Cells of Some Heterocyclic Chalcones

    Directory of Open Access Journals (Sweden)

    Tuong-Ha Do

    2016-03-01

    Full Text Available Chemically diverse heterocyclic chalcones were prepared and evaluated for cytotoxicity, aiming to push forward potency and selectivity. They were tested against rhabdomyosarcoma (RMS and noncancerous cell line (LLC-PK1. The influence of heteroaryl patterns on rings A and B was studied. Heterocycle functionalities on both rings, such as phenothiazine, thiophene, furan and pyridine were evaluated. Notably, the introduction of three methoxy groups at positions 3, 4, 5 on ring B appears to be critical for cytotoxicity. The best compound, with potent and selective cytotoxicity (IC50 = 12.51 μM in comparison with the value 10.84 μM of paclitaxel, contains a phenothiazine moiety on ring A and a thiophene heterocycle on ring B. Most of the potential compounds only show weak cytoxicity on the noncancerous cell line LLC-PK1.

  17. Cytotoxicity evaluation of Ziziphus mauritiana and Oenanthe javanica on Chang liver cell lines

    International Nuclear Information System (INIS)

    Ziziphus mauritiana and Oenanthe javanica which are known as bidara and selom have various uses in traditional medicine. The leaves of bidara are helpful in liver disease, asthma, spiritual treatment and fever whereas selom has been widely used to treat fever, abdominal pain, leucorrhea, and urinary problems. Even though these plants have been widely used as traditional remedy, no cytotoxic evaluation has been carried out. In this study, cytotoxicity activity of both plants was evaluated in vitro against Chang liver cells using methyl thiazolyl tetrazolium (MTT) assay method. The IC50 value obtained for Ziziphus mauritiana methanolic extract and Oenanthe javanica aqueous extract were 17.23 mg/ ml and 28.13mg/ ml, respectively. This result illustrated that both plants did not produce any cytotoxic effect against Chang liver cells and considered to be toxicological safe to be taken by human for medicinal purposes. (author)

  18. Cellular distribution of inorganic mercury and its relation to cytotoxicity in bovine kidney cell cultures

    International Nuclear Information System (INIS)

    A bovine kidney cell culture system was used to assess what relationship mercuric chloride (HgCl2) uptake and subcellular distribution had to cytotoxicity. Twenty-four-hour incubations with 0.05-50 μM HgCl2 elicited a concentration-related cytotoxicity. Cellular accumulation of 203Hg was also concentration-related, with 1.0 nmol/106 cells at the IC50. Measurement of Hg uptake over the 24-h exposure period revealed a multiphasic process. Peak accumulation was attained by 1 h and was followed by extrusion and plateauing of intracellular Hg levels. Least-squares regression analysis of the cytotoxicity and cellular uptake data indicated a potential relationship between the Hg uptake and cytotoxicity. However, the subcellular distribution of Hg was not concentration-related. Mitochondria and soluble protein fractions accounted for greater than 65% of the cell-associated Hg at all concentrations. The remaining Hg was distributed between the microsomal (6-10%) and nuclear and cell debris (11-22%) fractions at all concentrations tested. Less than 20% of the total cell-associated Hg was bound with metallothionein-like protein. 31 references, 4 figures, 3 tables

  19. Dendrimer-curcumin conjugate: a water soluble and effective cytotoxic agent against breast cancer cell lines.

    Science.gov (United States)

    Debnath, Shawon; Saloum, Darin; Dolai, Sukanta; Sun, Chong; Averick, Saadyah; Raja, Krishnaswami; Fata, Jimmie E

    2013-12-01

    Curcumin, which is derived from the plant Curcuma longa, has received considerable attention as a possible anti-cancer agent. In cell culture, curcumin is capable of inducing apoptosis in cancer cells at concentrations that do not affect normal cells. One draw-back holding curcumin back from being an effective anti-cancer agent in humans is that it is almost completely insoluble in water and therefore has poor absorption and subsequently poor bioavailability. Here we have generated a number of curcumin derivatives (tetrahydro-curcumin, curcumin mono-carboxylic acid, curcumin mono-galactose, curcumin mono-alkyne and dendrimer-curcumin conjugate) to test whether any of them display both cytotoxicity and water solubility. Of those tested only dendrimer-curcumin conjugate exhibited both water solubility and cytotoxicity against SKBr3 and BT549 breast cancer cells. When compared to curcumin dissolved in DMSO, dendrimer-curcumin conjugate dissolved in water was significantly more effective in inducing cytotoxicity, as measured by the MTT assay and effectively induced cellular apoptosis measured by caspase-3 activation. Since dendrimer-curcumin conjugate is water soluble and capable of inducing potent cytotoxic effects on breast cancer cell lines, it may prove to be an effective anti-cancer therapy to be used in humans. PMID:23387971

  20. Cytotoxicity and genotoxicity of intravitreal adalimumab administration in rabbit retinal cells

    Directory of Open Access Journals (Sweden)

    Álcio Coutinho de Paula

    2015-04-01

    Full Text Available Purpose: To assess the cytotoxicity and genotoxicity of intravitreal adalimumab treatment in an animal experimental model using cytological and molecular techniques. Methods: Eighteen rabbits were randomly assigned to three groups: control, adalimumab treatment, and placebo. Cytotoxicity on retinal cells was evaluated using flow cytometry assays to determine the level of apoptosis and necrosis. Genotoxicity was evaluated by comet assays to assess DNA damage, and quantitative real-time polymerase chain reaction (qPCR was used to evaluate expression of apoptosis-inducing caspases (8 and 3. Results: No cytotoxicity or genotoxicity was observed in any of the two treatment groups (adalimumab and placebo following intravitreal administration compared with the control group. Flow cytometry analysis revealed that more than 90% of the cells were viable, and only a low proportion of retinal cells presented apoptotic (~10% or necrotic (<1% activity across all groups. Molecular damage was also low with a maximum of 6.4% DNA degradation observed in the comet assays. In addition, no increase in gene expression of apoptosis-inducing caspases was observed on retinal cells by qPCR in both the adalimumab and placebo groups compared with the control group. Conclusion: The use of adalimumab resulted in no detectable cytotoxicity or genotoxicity on retinal cells for up to 60 days upon administration. These results therefore indicate that adalimumab may be a safe option for intravitreal application to treat ocular inflammatory diseases in which TNF-α is involved.

  1. Differential cytotoxic effects of arsenic on human and animal cells.

    OpenAIRE

    Lee, T C; Ho, I C

    1994-01-01

    Human fibroblasts (HFW) were 10-fold more susceptible than Chinese hamster ovary (CHO-K1) cells to sodium arsenite. Comparison of cellular antioxidant enzyme activities showed that CHO-K1 cells contained 3- and 8-fold more glutathione-peroxidase and catalase activities, respectively, than HFW cells. Since vitamin E, methylamine, and benzyl alcohol could prevent, in part, the arsenite-induced killing of HFW cells, we suggest that arsenite can induce oxidative damage in HFW cells. We have also ...

  2. Non-synergistic cytotoxic effects of Fusarium and Alternaria toxin combinations in Caco-2 cells.

    Science.gov (United States)

    Vejdovszky, Katharina; Warth, Benedikt; Sulyok, Michael; Marko, Doris

    2016-01-22

    Exposure of humans and animals to mycotoxins via food and feed generally involves a conglomeration of compounds contaminating the consumed products. Investigations on combinatory effects of mycotoxins are therefore of great importance. In this study, cytotoxic effects of binary mixtures of the Fusarium toxins enniatin B, aurofusarin, deoxynivalenol, nivalenol and zearalenone, and tenuazonic acid produced by Alternaria spp., were evaluated by the WST-1 assay in the colorectal carcinoma cell-line Caco-2 after 24h of incubation. The selection of these mycotoxins was based on typically occurring natural contamination patterns in grains. Aurofusarin, which can be found abundantly in contaminated foodstuff and has not been toxicologically characterized properly so far, showed pronounced cytotoxicity, decreasing the mitochondrial activity at 10μM to 51% compared to a solvent control. Combinations of other mycotoxins with aurofusarin showed additive effects. In contrast, binary mixtures of enniatin B, deoxynivalenol, nivalenol and zearalenone at cytotoxic concentrations, predominantly resulted in antagonistic effects. Binary combinations of these four Fusarium toxins with tenuazonic acid also revealed interacting effects leading to a decrease in cytotoxicity, compared to expected combinatory effects. Especially in combination with deoxynivalenol, tenuazonic acid was found to significantly reduce the cytotoxicity of this mycotoxin in Caco-2 cells. Synergistic effects were not observed for any toxin combination under the chosen conditions. PMID:26529482

  3. Exogenous albumin inhibits sorafenib-induced cytotoxicity in human cancer cell lines

    OpenAIRE

    Kanno, Syu-ichi; ITOH, KATSUYUKI; Suzuki, Naoto; TOMIZAWA, AYAKO; Yomogida, Shin; ISHIKAWA, MASAAKI

    2012-01-01

    Sorafenib is an orally administered multikinase inhibitor that exhibits anti-angiogenic and anti-tumor activity. Sorafenib is also known to bind to protein (>99.5%), suggesting protein binding may be involved in sorafenib pharmacokinetic variability. Albumin is a major drug-binding protein. In this study, we examined the effect of albumin on sorafenib-induced cytotoxicity using two in vitro culture cell lines, human hepatoma Huh-7 cells and androgen-independent prostate cancer PC-3 cells. The...

  4. Rapid Ped-2E9 Cell-Based Cytotoxicity Analysis and Genotyping of Bacillus Species

    OpenAIRE

    Gray, Kristen M.; Banada, Padmapriya P.; O'Neal, Erin; Arun K. Bhunia

    2005-01-01

    Bacillus species causing food-borne disease produce multiple toxins eliciting gastroenteritis. Toxin assays with mammalian cell cultures are reliable but may take 24 to 72 h to complete and also lack sensitivity. Here, a sensitive and rapid assay was developed using a murine hybridoma Ped-2E9 cell model. Bacillus culture supernatants containing toxins were added to a Ped-2E9 cell line and analyzed for cytotoxicity with an alkaline phosphatase release assay. Most Bacillus cereus strains produc...

  5. Cytotoxicity and cell cycle effects of novel indolo[2,3-b]quinoline derivatives.

    Science.gov (United States)

    Humeniuk, Rita; Kaczmarek, Lukasz; Peczyńska-Czoch, Wanda; Marcinkowska, Ewa

    2003-01-01

    Cellular effects of novel indolo[2,3-b]quinoline derivatives were studied. These compounds are synthetic analogs of plant alkaloid neocryptolepine (5-methyl-5H-indolo[2,3-b]quinoline) present in extracts from Cryptolepis sanguinolenta. They are traditionally used in natural medicine in Central and West Africa. Previous molecular and computational studies indicated that these compounds were DNA intercalators and inhibitors of topoisomerase II. We have extended our studies on their mode of action to the cellular level. Past experiments have shown that these compounds were active in vitro against cell lines derived from solid tumors, so for the present studies we selected leukemic cell lines. Jurkat acute T cell, CCRF-CEM T lymphoblastoid, THP-1 acute monocytic, HL-60 acute promyelocytic leukemias, and HL-60/MX2 subline with reduced expression of topoisomerase II were used. We evaluated the cytotoxicity and cell cycle effects of the indolo[2,3-b]quinoline compounds. We also tested if these compounds were able to induce apoptosis in the cells. Our studies revealed that novel indolo[2,3-b]quinoline derivatives were more cytotoxic to all cell lines than etoposide (used as a reference topoisomerase II inhibitor), and that their cytotoxicity depended on the substituents introduced to the indolo[2,3-b]quinoline core. Surprisingly, our studies have shown that HL-60/MX2 cell line and also THP-1 cell line, resistant to etoposide, were susceptible to methyl- and methoxy-substituted indolo[2,3-b]quinoline derivatives. In parallel to the evaluation of cytotoxicity we studied cell cycle effects of these compounds. Treatment of HL-60 cells with etoposide in subcytotoxic concentrations resulted in a massive accumulation of the cells in the G2/M phase of the cell cycle. When we used subcytotoxic concentrations of our novel indolo[2,3-b]quinoline derivatives the cell cycle progression of HL-60 cells was not affected. Moreover, the cell cycle of HL-60/MX2 cells was not influenced by

  6. Cytotoxic effect of Erythroxylum daphnites extract is associated with G1 cell cycle arrest and apoptosis in oral squamous cell carcinoma.

    Science.gov (United States)

    Elias, Silvia T; Macedo, Carolina C S; Simeoni, Luiz A; Silveira, Dâmaris; Magalhães, Pérola O; Lofrano-Porto, Adriana; Coletta, Ricardo D; Neves, Francisco A R; Guerra, Eliete N S

    2016-04-01

    Plant-derived molecules showing antineoplastic effects have recently gained increased attention as potential adjuvants to traditional therapies for various cancers. Cerrado biome in Brazil contains high floral biodiversity, but knowledge about the potential therapeutic effects of compounds derived from that flora is still limited. The present study investigated the antineoplastic activity of Erythroxylum daphnites Mart., a Brazilian native plant from Cerrado biome, in the SCC-9 oral squamous cell carcinoma cell line. Cells were treated with various concentrations of hexane extract of Erythroxylum daphnites leaves (EDH) and assessed for cytotoxicity, proliferation, and apoptosis. Thin layer chromatography was conducted to characterize the substances present in EDH. Our results showed that EDH exerted anti-proliferative effects in SCC-9 cells by stabilizing the cell cycle at G1 phase in association with reduced intracellular levels of cyclins D and E and increased level of p21. EDH also demonstrated pro-apoptotic properties, as shown by an increased expression of caspase-3. Triterpenes were the major constituents of EDH. Our findings demonstrated a cytotoxic effect of EDH against SCC-9 cells in vitro mediated by the restraint of cellular proliferation and induction of apoptosis. Taken together, these findings support EDH constituents as potential therapeutic adjuvants for oral cancer. PMID:26918580

  7. The ROS-induced cytotoxicity of ascorbate is attenuated by hypoxia and HIF-1alpha in the NCI60 cancer cell lines.

    Science.gov (United States)

    Sinnberg, Tobias; Noor, Seema; Venturelli, Sascha; Berger, Alexander; Schuler, Paul; Garbe, Claus; Busch, Christian

    2014-03-01

    Intravenous application of high-dose ascorbate is used in complementary palliative medicine to treat cancer patients. Pharmacological doses of ascorbate in the mM range induce cytotoxicity in cancer cells mediated by reactive oxygen species (ROS), namely hydrogen peroxide and ascorbyl radicals. However, little is known about intrinsic or extrinsic factors modulating this ascorbate-mediated cytotoxicity. Under normoxia and hypoxia, ascorbate IC50 values were determined on the NCI60 cancer cells. The cell cycle, the influence of cobalt chloride-induced hypoxia-inducible factor-1α (HIF-1α) and the glucose transporter 1 (GLUT-1) expression (a pro-survival HIF-1α-downstream-target) were analysed after ascorbate exposure under normoxic and hypoxic conditions. The amount of ascorbyl radicals increased with rising serum concentrations. Hypoxia (0.1% O2 ) globally increased the IC50 of ascorbate in the 60 cancer cell lines from 4.5 ± 3.6 mM to 10.1 ± 5.9 mM (2.2-fold increase, P < 0.001, Mann-Whitney t-test), thus inducing cellular resistance towards ascorbate. This ascorbate resistance depended on HIF-1α-signalling, but did not correlate with cell line-specific expression of the ascorbate transporter GLUT-1. However, under normoxic and hypoxic conditions, ascorbate treatment at the individual IC50 reduced the expression of GLUT-1 in the cancer cells. Our data show a ROS-induced, HIF-1α- and O2 -dependent cytotoxicity of ascorbate on 60 different cancer cells. This suggests that for clinical application, cancer patients should additionally be oxygenized to increase the cytotoxic efficacy of ascorbate. PMID:24330097

  8. Candidate mosaic proteins for a pan-filoviral cytotoxic T-Cell lymphocyte vaccine

    Energy Technology Data Exchange (ETDEWEB)

    Fenimore, Paul W [Los Alamos National Laboratory; Fischer, William M [Los Alamos National Laboratory; Kuiken, Carla [Los Alamos National Laboratory; Foley, Brian T [Los Alamos National Laboratory; Thurmond, J R [Los Alamos National Laboratory; Yusim, K [Los Alamos National Laboratory; Korber, B T [Los Alamos National Laboratory

    2008-01-01

    The extremely high fatality rates of many filovirus (FILV) strains the recurrent but rarely identified origin of human epidemics, the only partly identified viral reservoirs and the continuing non-human primate epizootics in Africa make a broadly-protective filovirus vaccine highly desirable. Cytotoxic T-cells (CTL) have been shown to be protective in mice, guinea pigs and non-human primates. In murine models the cytotoxic T-cell epitopes that are protective against Ebola virus have been mapped and in non-human primates CTL-mediated protection between viral strains (John Dye: specify) has been demonstrated using two filoviral proteins, nucleoprotein (NP) and glycoprotein (GP). These immunological results suggest that the CTL avenue of immunity deserves consideration for a vaccine. The poorly-understood viral reservoirs means that it is difficult to predict what strains are likely to cause epidemics. Thus, there is a premium on developing a pan-filoviral vaccine. The genetic diversity of FILV is large, roughly the same scale as human immunodeficiency virus (HIV). This presents a serious challenge for the vaccine designer because a traditional vaccine aspiring to pan-filoviral coverage is likely to require the inclusion of many antigenic reagents. A recent method for optimizing cytotoxic T-cell lymphocyte epitope coverage with mosaic antigens was successful in improving potential CTL epitope coverage against HIV and may be useful in the context of very different viruses, such as the filoviruses discussed here. Mosaic proteins are recombinants composed of fragments of wild-type proteins joined at locations resulting in exclusively natural k-mers, 9 {le} k {le} 15, and having approximately the same length as the wild-type proteins. The use of mosaic antigens is motivated by three conjectures: (1) optimizing a mosaic protein to maximize coverage of k-mers found in a set of reference proteins will give better odds of including broadly-protective CTL epitopes in a vaccine

  9. A biophysical model of cell evolution after cytotoxic treatments: Damage, repair and cell response.

    Science.gov (United States)

    Tomezak, M; Abbadie, C; Lartigau, E; Cleri, F

    2016-01-21

    We present a theoretical agent-based model of cell evolution under the action of cytotoxic treatments, such as radiotherapy or chemotherapy. The major features of cell cycle and proliferation, cell damage and repair, and chemical diffusion are included. Cell evolution is based on a discrete Markov chain, with cells stepping along a sequence of discrete internal states from 'normal' to 'inactive'. Probabilistic laws are introduced for each type of event a cell can undergo during its life: duplication, arrest, senescence, damage, reparation, or death. We adjust the model parameters on a series of cell irradiation experiments, carried out in a clinical LINAC, in which the damage and repair kinetics of single- and double-strand breaks are followed. Two showcase applications of the model are then presented. In the first one, we reconstruct the cell survival curves from a number of published low- and high-dose irradiation experiments. We reobtain a very good description of the data without assuming the well-known linear-quadratic model, but instead including a variable DSB repair probability. The repair capability of the model spontaneously saturates to an exponential decay at increasingly high doses. As a second test, we attempt to simulate the two extreme possibilities of the so-called 'bystander' effect in radiotherapy: the 'local' effect versus a 'global' effect, respectively activated by the short-range or long-range diffusion of some factor, presumably secreted by the irradiated cells. Even with an oversimplified simulation, we could demonstrate a sizeable difference in the proliferation rate of non-irradiated cells, the proliferation acceleration being much larger for the global than the local effect, for relatively small fractions of irradiated cells in the colony. PMID:26549470

  10. PD-L1 Expression on Retrovirus-Infected Cells Mediates Immune Escape from CD8+ T Cell Killing.

    Directory of Open Access Journals (Sweden)

    Ilseyar Akhmetzyanova

    2015-10-01

    Full Text Available Cytotoxic CD8+ T Lymphocytes (CTL efficiently control acute virus infections but can become exhausted when a chronic infection develops. Signaling of the inhibitory receptor PD-1 is an important mechanism for the development of virus-specific CD8+ T cell dysfunction. However, it has recently been shown that during the initial phase of infection virus-specific CD8+ T cells express high levels of PD-1, but are fully competent in producing cytokines and killing virus-infected target cells. To better understand the role of the PD-1 signaling pathway in CD8+ T cell cytotoxicity during acute viral infections we analyzed the expression of the ligand on retrovirus-infected cells targeted by CTLs. We observed increased levels of PD-L1 expression after infection of cells with the murine Friend retrovirus (FV or with HIV. In FV infected mice, virus-specific CTLs efficiently eliminated infected target cells that expressed low levels of PD-L1 or that were deficient for PD-L1 but the population of PD-L1high cells escaped elimination and formed a reservoir for chronic FV replication. Infected cells with high PD-L1 expression mediated a negative feedback on CD8+ T cells and inhibited their expansion and cytotoxic functions. These findings provide evidence for a novel immune escape mechanism during acute retroviral infection based on PD-L1 expression levels on virus infected target cells.

  11. Protein-binding, cytotoxicity in vitro and cell cycle arrest of ruthenium(II) polypyridyl complexes

    Science.gov (United States)

    Liu, Si-Hong; Zhu, Jian-Wei; Xu, Hui-Hua; Wang, Yan; Liu, Ya-Min; Liang, Jun-Bo; Zhang, Gui-Qiang; Cao, Di-Hua; Lin, Yang-Yang; Wu, Yong; Guo, Qi-Feng

    2016-05-01

    The cytotoxic activity of two Ru(II) complexes against A549, BEL-7402, HeLa, PC-12, SGC-7901 and SiHa cell lines was investigated by MTT method. Complexes 1 and 2 show moderate cytotoxicity toward BEL-7402 cells with an IC50 value of 53.9 ± 3.4 and 39.3 ± 2.1 μM. The effects of the complexes inducing apoptosis, cellular uptake, reactive oxygen species and mitochondrial membrane potential in BEL-7402 cells have been studied by fluorescence microscopy. The percentages of apoptotic and necrotic cells and cell cycle arrest were studied by flow cytometry. The BSA-binding behaviors were investigated by UV/visible and fluorescent spectra.

  12. Cytotoxic effect of soil cyanobacterial extracts to mammal cell lines YAC-1 and WEHI

    Czech Academy of Sciences Publication Activity Database

    Hrouzek, Pavel; Kopecký, Jiří; Salát, Jiří; Maršálek, Blahoslav; Lukešová, Alena

    2005-01-01

    Roč. 5, - (2005), s. 79-90. ISSN 1213-3434 Institutional research plan: CEZ:AV0Z60050516; CEZ:AV0Z60660521 Keywords : cytotoxic effect * soil cyanobacterial extracts * mammal cell lines YAC-1 and WEHI Subject RIV: EH - Ecology, Behaviour

  13. Dicoumarol enhances gemcitabine-induced cytotoxicity in high NQO1-expressing cholangiocarcinoma cells

    Institute of Scientific and Technical Information of China (English)

    Benjaporn; Buranrat; Auemduan; Prawan; Upa; Kukongviriyapan; Sarinya; Kong-petch; Veerapol; Kukongviriyapan

    2010-01-01

    AIM: To investigate whether dicoumarol, a potent inhibitor of NAD(P)H quinone oxidoreductase-1 (NQO1), potentiates gemcitabine to induce cytotoxicity in chol-angiocarcinoma cells (CCA) and the role of reactive oxygen generation in sensitizing the cells. METHODS: Four human cell lines with different NQO1 activity were used; the human CCA cell lines, KKU-100, KKU-OCA17, KKU-M214, and Chang liver cells. NQO1 activity and mRNA expression were determined. The cells were pretreated with dicoumarol at relevant con...

  14. Inefficient boosting of antitumor CD8+ T cells by dendritic-cell vaccines is rescued by restricting T-cell cytotoxic functions

    OpenAIRE

    Zhi-Iong Ma, Joel; Yang, Jianping; Qin, Jim S.; Richter, Antonia; PERRET, Rachel; El-Deiry, Wafik S.; Finnberg, Niklas; Ronchese, Franca

    2012-01-01

    Dendritic cells (DCs) are powerful activators of primary and secondary immune responses and have promising activity as anticancer vaccines. However, various populations of immune cells, including natural killer cells, regulatory T cells and especially cytotoxic T lymphocytes (CTLs), can inhibit DC function through cytotoxic clearance. Spontaneous tumor-specific CTL responses are frequently observed in patients before immunotherapy, and it is unclear how such pre-existing responses may affect ...

  15. Subamolide B Isolated from Medicinal Plant Cinnamomum subavenium Induces Cytotoxicity in Human Cutaneous Squamous Cell Carcinoma Cells through Mitochondrial and CHOP-Dependent Cell Death Pathways

    OpenAIRE

    Shu-Yi Yang; Hui-Min Wang; Tai-Wen Wu; Yi-Ju Chen; Jeng-Jer Shieh; Ju-Hwa Lin; Tsing-Fen Ho; Ren-Jie Luo; Chung-Yi Chen; Chia-Che Chang

    2013-01-01

    Subamolide B is a butanolide isolated from Cinnamomum subavenium, a medicinal plant traditionally used to treat various ailments including carcinomatous swelling. We herein reported for the first time that subamolide B potently induced cytotoxicity against diverse human skin cancer cell lines while sparing nonmalignant cells. Mechanistic studies on human cutaneous squamous cell carcinoma (SCC) cell line SCC12 highlighted the involvement of apoptosis in subamolide B-induced cytotoxicity, as ev...

  16. Cytotoxic Activity of Dendritic Cells as a Possible Mechanism of Negative Regulation of T Lymphocytes in Pulmonary Tuberculosis

    Directory of Open Access Journals (Sweden)

    Ludmila V. Sakhno

    2012-01-01

    Full Text Available The PD-1/B7-H1-mediated induction of T cell apoptosis/anergy as a possible mechanism of immune response failure was studied in 76 patients with pulmonary tuberculosis (TB with normal and low-proliferative response to antigens of M. tuberculosis (purified protein derivative (PPD. It was revealed that dendritic cells (DCs, generated in vitro from patient blood monocytes with GM-CSF + IFN-α, were characterized by increased B7-H1 expression, upproduction of IL-10, and reducing of allostimulatory activity in mixed lymphocyte culture (MLC. Moreover, DCs of patients with TB were able to enhance T cell apoptosis and to block T-cell division in MLC. It was shown that neutralizing anti-PD1 antibodies significantly decreased the proapoptogenic/tolerogenic effect of DCs. Correlation analysis revealed a direct relationship between IL-10 production and level of B7-H1 expression in the general group of investigated patients. It was demonstrated that generation of healthy donor DCs in the presence of IL-10 led to an increase in the number of DCs-expressed B7-H1 molecule, DC proapoptogenic activity, and a decrease in their allostimulatory activity. Obviously, the revealed phenomenon of the PD-1/B7-H1-mediated pro-apoptogenic activity of DCs is clinically significant since the cytotoxic/tolerogenic potential of DCs is more pronounced in patients with PPD anergy.

  17. Correlation of particle properties with cytotoxicity and cellular uptake of hydroxyapatite nanoparticles in human gastric cancer cells.

    Science.gov (United States)

    Cui, Xinhui; Liang, Tong; Liu, Changsheng; Yuan, Yuan; Qian, Jiangchao

    2016-10-01

    Three types of hydroxyapatite nanoparticles (HAPNs) were synthesized employing a sonochemistry-assisted microwave method by changing microwave power (from 200 to 300W) or using calcination treatment: L200 (200W, lyophilization), L300 (300W, lyophilization) and C200 (200W, lyophilization & calcination). Their physiochemical properties were characterized and correlated with cytotoxicity to human gastric cancer cells (MGC80-3). The major differences among these HAPN preparations were their size and specific surface area, with the L200 showing a smaller size and higher specific surface area. Although all HAPNs inhibited cell proliferation and induced apoptosis of cancer cells, L200 exhibited the greatest toxicity. All types of HAPNs were internalized through energy-dependent pathways, but the L200 nanoparticles were more efficiently uptaken by MGC80-3 cells. Inhibitor studies with dynasore and methyl-β-cyclodextrin suggested that caveolae-mediated endocytosis and, to a much lesser extent, clathrin-mediated endocytosis, were involved in cellular uptake of the various preparations, whereas the inhibition of endocytosis was more obvious for L200. Using fluorescein isothiocyanate-labeled HAPNs and laser-scanning confocal microscopy, we found that all forms of nanoparticles were present in the cytoplasm, and some L200 HAPNs were even found within nuclei. Treatment with all HAPN preparations led to the increase in the intracellular calcium level with the highest level detected for L200. PMID:27287142

  18. δ-Aminolevulinic acid cytotoxic effects on human hepatocarcinoma cell lines

    Directory of Open Access Journals (Sweden)

    del Batlle Alcira M

    2002-03-01

    Full Text Available Abstract Background Acute Intermittent Porphyria is a genetic disorder of heme metabolism, characterized by increased levels of porphyrin precursors, δ-aminolevulinic acid (ALA and porphobilinogen (PBG. ALA has been reported to generate reactive oxygen species and to cause oxidative damage to proteins, subcellular structures and DNA. It is known that oxidative stress can induce apoptosis. The aim of this work was to study the cytotoxic effect of ALA on two hepatocarcinoma cell lines. Results We have determined the impact of ALA on HEP G2 and HEP 3B hepatocarcinoma cell lines survival as measured by the MTT assay. ALA proved to be cytotoxic in both cell lines however; HEP G2 was more sensitive to ALA than HEP 3B. Addition of hemin or glucose diminished ALA cytotoxicity in HEP G2 cells; instead it was enhanced in HEP 3B cells. Because apoptosis is usually associated with DNA fragmentation, the DNA of ALA treated and untreated cells were analyzed. The characteristic pattern of DNA fragmentation ladders was observed in ALA treated cells. To elucidate the mechanisms of ALA induced apoptosis, we examined its effect on p53 expression. No changes in p53 mRNA levels were observed after exposure of both cell lines to ALA for 24 h. CDK2 and CDK4 protein levels were reduced after ALA treatment at physiological concentrations.

  19. Cytotoxic Effects of Tropodithietic Acid on Mammalian Clonal Cell Lines of Neuronal and Glial Origin

    Directory of Open Access Journals (Sweden)

    Heidi Wichmann

    2015-11-01

    Full Text Available The marine metabolite tropodithietic acid (TDA, produced by several Roseobacter clade bacteria, is known for its broad antimicrobial activity. TDA is of interest not only as a probiotic in aquaculture, but also because it might be of use as an antibacterial agent in non-marine or non-aquatic environments, and thus the potentially cytotoxic influences on eukaryotic cells need to be evaluated. The present study was undertaken to investigate its effects on cells of the mammalian nervous system, i.e., neuronal N2a cells and OLN-93 cells as model systems for nerve cells and glia. The data show that in both cell lines TDA exerted morphological changes and cytotoxic effects at a concentration of 0.3–0.5 µg/mL (1.4–2.4 µM. Furthermore, TDA caused a breakdown of the mitochondrial membrane potential, the activation of extracellular signal-regulated kinases ERK1/2, and the induction of the small heat shock protein HSP32/HO-1, which is considered as a sensor of oxidative stress. The cytotoxic effects were accompanied by an increase in intracellular Ca2+-levels, the disturbance of the microtubule network, and the reorganization of the microfilament system. Hence, mammalian cells are a sensitive target for the action of TDA and react by the activation of a stress response resulting in cell death.

  20. Cytotoxic Effects of Tropodithietic Acid on Mammalian Clonal Cell Lines of Neuronal and Glial Origin.

    Science.gov (United States)

    Wichmann, Heidi; Vocke, Farina; Brinkhoff, Thorsten; Simon, Meinhard; Richter-Landsberg, Christiane

    2015-12-01

    The marine metabolite tropodithietic acid (TDA), produced by several Roseobacter clade bacteria, is known for its broad antimicrobial activity. TDA is of interest not only as a probiotic in aquaculture, but also because it might be of use as an antibacterial agent in non-marine or non-aquatic environments, and thus the potentially cytotoxic influences on eukaryotic cells need to be evaluated. The present study was undertaken to investigate its effects on cells of the mammalian nervous system, i.e., neuronal N2a cells and OLN-93 cells as model systems for nerve cells and glia. The data show that in both cell lines TDA exerted morphological changes and cytotoxic effects at a concentration of 0.3-0.5 µg/mL (1.4-2.4 µM). Furthermore, TDA caused a breakdown of the mitochondrial membrane potential, the activation of extracellular signal-regulated kinases ERK1/2, and the induction of the small heat shock protein HSP32/HO-1, which is considered as a sensor of oxidative stress. The cytotoxic effects were accompanied by an increase in intracellular Ca(2+)-levels, the disturbance of the microtubule network, and the reorganization of the microfilament system. Hence, mammalian cells are a sensitive target for the action of TDA and react by the activation of a stress response resulting in cell death. PMID:26633426

  1. δ-Aminolevulinic acid cytotoxic effects on human hepatocarcinoma cell lines

    International Nuclear Information System (INIS)

    Acute Intermittent Porphyria is a genetic disorder of heme metabolism, characterized by increased levels of porphyrin precursors, δ-aminolevulinic acid (ALA) and porphobilinogen (PBG). ALA has been reported to generate reactive oxygen species and to cause oxidative damage to proteins, subcellular structures and DNA. It is known that oxidative stress can induce apoptosis. The aim of this work was to study the cytotoxic effect of ALA on two hepatocarcinoma cell lines. We have determined the impact of ALA on HEP G2 and HEP 3B hepatocarcinoma cell lines survival as measured by the MTT assay. ALA proved to be cytotoxic in both cell lines however; HEP G2 was more sensitive to ALA than HEP 3B. Addition of hemin or glucose diminished ALA cytotoxicity in HEP G2 cells; instead it was enhanced in HEP 3B cells. Because apoptosis is usually associated with DNA fragmentation, the DNA of ALA treated and untreated cells were analyzed. The characteristic pattern of DNA fragmentation ladders was observed in ALA treated cells. To elucidate the mechanisms of ALA induced apoptosis, we examined its effect on p53 expression. No changes in p53 mRNA levels were observed after exposure of both cell lines to ALA for 24 h. CDK2 and CDK4 protein levels were reduced after ALA treatment at physiological concentrations

  2. Real-time cell-microelectronic sensing of nanoparticle-induced cytotoxic effects

    Energy Technology Data Exchange (ETDEWEB)

    Moe, Birget [Division of Analytical and Environmental Toxicology, Department of Laboratory Medicine and Pathology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Canada T6G 2G3 (Canada); Gabos, Stephan [Alberta Health, 24th floor, Telus Plaza North Tower, 10025 Jasper Avenue, Edmonton, Canada T5J 2N3 (Canada); Li, Xing-Fang, E-mail: xingfang.li@ualberta.ca [Division of Analytical and Environmental Toxicology, Department of Laboratory Medicine and Pathology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Canada T6G 2G3 (Canada)

    2013-07-30

    Graphical abstract: Cell-electronic sensing of 96 tests of nanoparticles. -- Highlights: •Cell-electronic sensing of cytotoxic effects of nanoparticles. •Simultaneous sensing of 96 tests. •Multiplex data of real-time dynamic responses. •Unique temporal IC{sub 50} histograms. •Minimized interference and high throughput analysis. -- Abstract: We report a real-time cell analysis (RTCA) sensing method of 96 electronic microwells for profiling the cytotoxicity of nanoparticles on different cell lines. The method consists of 96 microwells embedded with microelectrodes (96x E-plate) to measure impedance changes of adherent cell lines. When the testing cells change in population, adhesion, and/or morphology, the impedance at the cell–electrode interface changes to provide real-time monitoring of overall cell status. To demonstrate this technique, we used three cell lines as sensing probes: two human lung carcinoma cell lines, A549 and SK-MES-1, and a normal mammalian cell line, CHO-K1. We tested two well-characterized nanoparticles: nano-titanium dioxide (nTiO{sub 2}) and nano-silver (nAg). The three cell lines were separately seeded into 96x E-plates and treated with varying concentrations of nanoparticles (0.078–160 μg mL{sup −1}). This method provides dynamic cell response profiles and temporal IC{sub 50} histograms, showing concentration-, time-, particle-, and cell-dependent cytotoxicity. The 24 h and 48 h IC{sub 50} values of nAg obtained using both the RTCA and the neutral red uptake (NRU) assays were in good agreement, validating the RTCA technique. The RTCA assay does not suffer interference from nTiO{sub 2}, whereas the NRU assay cannot be used due to severe interference from nTiO{sub 2}. A cytostatic response was observed in CHO-K1 cells after 24 h exposure to 40 μg mL{sup −1} nTiO{sub 2}, which was correlated with S-phase cell cycle arrest based on cell cycle analysis using flow cytometry. This suggests that the shapes of the response curves

  3. Isolation of motile Aeromonas spp. from fish and their cytotoxic effect on Vero cell cultures

    Directory of Open Access Journals (Sweden)

    Karabasil Neđeljko

    2002-01-01

    Full Text Available The presence of motile Aeromonas spp. in fish and other sea food on the Belgrade retail market was investigated with the aim of determining the ability of these bacteria to produce and secrete toxins. Nine strains of motile Aeromonas spp. were isolated from seventy-eight food samples. Aer. sobria was identified in three cases, while six of the obtained strains were identified as Aer. hydrophila. Strains of motile Aeromonas spp. from different sources were analyzed for cytotoxicity on Vero cell cultures. A cytotoxic effect was detected for all tested strains, but of different intensity.

  4. Fibronectin mediates mesendodermal cell fate decisions

    Science.gov (United States)

    Cheng, Paul; Andersen, Peter; Hassel, David; Kaynak, Bogac L.; Limphong, Pattraranee; Juergensen, Lonny; Kwon, Chulan; Srivastava, Deepak

    2013-01-01

    Non-cell-autonomous signals often play crucial roles in cell fate decisions during animal development. Reciprocal signaling between endoderm and mesoderm is vital for embryonic development, yet the key signals and mechanisms remain unclear. Here, we show that endodermal cells efficiently promote the emergence of mesodermal cells in the neighboring population through signals containing an essential short-range component. The endoderm-mesoderm interaction promoted precardiac mesoderm formation in mouse embryonic stem cells and involved endodermal production of fibronectin. In vivo, fibronectin deficiency resulted in a dramatic reduction of mesoderm accompanied by endodermal expansion in zebrafish embryos. This event was mediated by regulation of Wnt signaling in mesodermal cells through activation of integrin-β1. Our findings highlight the importance of the extracellular matrix in mediating short-range signals and reveal a novel function of endoderm, involving fibronectin and its downstream signaling cascades, in promoting the emergence of mesoderm. PMID:23715551

  5. Silencing of the transcription factor STAT3 sensitizes lung cancer cells to DNA damaging drugs, but not to TNFα- and NK cytotoxicity

    International Nuclear Information System (INIS)

    Transcription factor STAT3 (Signal Transducers and Activators of Transcription 3) is persistently active in human tumors and may contribute to tumor progression. Inhibition of STAT3 expression/activity could be a good strategy to modulate tumor cell survival and responses to cancer chemotherapeutics or immune cytotoxicity. We silenced STAT3 expression in human A549 lung cancer cells to elucidate its role in cell survival and resistance to chemotherapeutics, TNFα and natural killer (NK)-mediated cytotoxicity. We demonstrate that STAT3 is not essential for basal survival and proliferation of A549 cancer cells. Stable silencing of STAT3 expression sensitized A549 cells to DNA damaging chemotherapeutics doxorubicin and cisplatin in a p53-independent manner. Sensitization to DNA damage-inducing chemotherapeutics could be due to down-regulation of the Bcl-xL expression in STAT3 depleted cells. In contrast, knockdown of STAT3 in cancer cells did not modulate responses to TNFα and NK-mediated cytotoxicity. We found that STAT3 depletion increased the NFκB activity likely providing the compensatory, pro-survival signal. The treatment with TNFα, but not doxorubicin, enhanced this effect. We conclude that STAT3 is not crucial for the control of basal cell proliferation and survival of lung carcinoma cells but modulates susceptibility to DNA damaging chemotherapeutics by regulation of intrinsic pro-survival pathways. - Highlights: ► STAT3 silencing is negligent for basal lung cancer cell viability and proliferation. ► STAT3 depletion sensitizes lung cancer cells to DNA damaging chemotherapeutics. ► STAT3 depletion has no effect on susceptibility to extrinsic apoptosis inducers. ► Increased pro-survival NFκB activity may compensate for STAT3 depletion

  6. Silencing of the transcription factor STAT3 sensitizes lung cancer cells to DNA damaging drugs, but not to TNFα- and NK cytotoxicity

    Energy Technology Data Exchange (ETDEWEB)

    Kulesza, Dorota W. [Laboratory of Transcription Regulation, Department of Cell Biology, The Nencki Institute of Experimental Biology, Warsaw (Poland); Postgraduate School of Molecular Medicine, Warsaw Medical University, Warsaw (Poland); Carré, Thibault; Chouaib, Salem [Unité INSERM U753, Institut de Cancérologie Gustave Roussy, Villejuif Cedex (France); Kaminska, Bozena, E-mail: bozenakk@nencki.gov.pl [Laboratory of Transcription Regulation, Department of Cell Biology, The Nencki Institute of Experimental Biology, Warsaw (Poland)

    2013-02-15

    Transcription factor STAT3 (Signal Transducers and Activators of Transcription 3) is persistently active in human tumors and may contribute to tumor progression. Inhibition of STAT3 expression/activity could be a good strategy to modulate tumor cell survival and responses to cancer chemotherapeutics or immune cytotoxicity. We silenced STAT3 expression in human A549 lung cancer cells to elucidate its role in cell survival and resistance to chemotherapeutics, TNFα and natural killer (NK)-mediated cytotoxicity. We demonstrate that STAT3 is not essential for basal survival and proliferation of A549 cancer cells. Stable silencing of STAT3 expression sensitized A549 cells to DNA damaging chemotherapeutics doxorubicin and cisplatin in a p53-independent manner. Sensitization to DNA damage-inducing chemotherapeutics could be due to down-regulation of the Bcl-xL expression in STAT3 depleted cells. In contrast, knockdown of STAT3 in cancer cells did not modulate responses to TNFα and NK-mediated cytotoxicity. We found that STAT3 depletion increased the NFκB activity likely providing the compensatory, pro-survival signal. The treatment with TNFα, but not doxorubicin, enhanced this effect. We conclude that STAT3 is not crucial for the control of basal cell proliferation and survival of lung carcinoma cells but modulates susceptibility to DNA damaging chemotherapeutics by regulation of intrinsic pro-survival pathways. - Highlights: ► STAT3 silencing is negligent for basal lung cancer cell viability and proliferation. ► STAT3 depletion sensitizes lung cancer cells to DNA damaging chemotherapeutics. ► STAT3 depletion has no effect on susceptibility to extrinsic apoptosis inducers. ► Increased pro-survival NFκB activity may compensate for STAT3 depletion.

  7. Biodegradation behavior and cytotoxicity of the composite membrane composed of beta-dicalcium pyrophosphate and glucose mediated (polyethylene glycol/chitosan).

    Science.gov (United States)

    Wang, Jian Wen; Hon, Min Hsiung

    2004-02-01

    The purpose of this study is to prepare and evaluate the biodegradation behavior and cytotoxicity of a composite membrane, G-beta-DCP, combining beta-dicalcium pyrophosphate (beta-DCP) ceramic particles and glucose mediated chitosan-polyethylene glycol (PEG) membrane. The cytotoxicity of the G-beta-DCP was examined by the in vitro method of NIH 3T3 fibroblast cell culture. Extracts were obtained by soaking the G-beta-DCP composite in lysozyme containing phosphate buffer solution for 2, 7, 14, 21 and 28 days, respectively. The substances released from the G-beta-DCP composite were analyzed by gas chromatography-mass spectrometry (GC-MAS) and inductively coupled plasma atomic emission spectrometry (ICP-AES). The change in morphologies, chemical composition and crystal structure was examined by scanning electron microscopy (SEM) and X-ray diffraction pattern (XRD). The results of extracts cocultured with fibroblasts show that the growth of fibroblasts would increase for the extracts obtained from different beta-DCP feeding weight G-beta-DCP composites after soaking for 7 days. After further increasing the soaking time, the cell number still increases. It is found that the glucose amine and calcium are gradually released from the G-beta-DCP composites, which is considered to be nutritious for the growth of the fibroblast. The release rate of calcium ion and glucosamine concentration can be regulated by feeding the beta-DCP. The degradation behavior of G-beta-DCP composite is considered as an "onion degradation model" that the G-beta-DCP degrades from outer layer to inner layer. The developed material should have a great potential as a cell substrate in the field of tissue engineering. PMID:15330046

  8. Cytotoxicity of Algae Extracts on Normal and Malignant Cells

    OpenAIRE

    Jane Liesveld; Karen Rosell; Jeremy Bechelli; Myra Coppage

    2011-01-01

    Algae preparations are commonly used in alternative medicine. We examined the effects of algae extracts on normal hematopoietic cells and leukemia cells. Ethanol extracts were prepared of Dunaliella salina (Dun), Astaxanthin (Ast), Spirulina platensis (Spir), and Aphanizomenon flos-aquae (AFA). Cell viability effects were completed by Annexin staining. Ast and AFA inhibited HL-60 and MV-4-11 whereas Dun and Spir had no effect. Primary AML blasts demonstrated increased apoptosis in AFA. Primar...

  9. Effects of radiation on IL-2 secretion and cytotoxicity of T cells

    International Nuclear Information System (INIS)

    Peripheral blood mononuclear cells (PBMC) from normal persons were irradiated with 1.6 Gy γ-rays in vitro. The method of indirect immunofluorescence was used for analysis of positive percentage of TCR, CD3 and CD25 of T cells. The method of 3H-TdR incorporation and release wa used for determination of IL-2 secretion and T cell cytotoxicity, and immunocytochemistry was used for analysis of expression of TCR and CD3. A decreasing pattern of TCR, CD3 and CD25 expression, IL-2 secretion, and T cell cytotoxicity depending on radiation dose was found. The inhibition of IL-2 secretion and cytotoxicity after irradiation of T cells was associated, in some degree, with decreasing expression and damaging activity of TCR, CD3 and CD25, whereas it was possible that the decreasing expression of TCR and CD3 at the cell surface was related to accumulation of TCR and CD3 in cytoplasm of irradiated T cells

  10. Cytotoxic effect of Erythroxylum suberosum combined with radiotherapy in head and neck cancer cell lines

    International Nuclear Information System (INIS)

    The mouth and oropharynx cancer is the 6th most common type of cancer in the world. The treatment may involve surgery, chemotherapy and radiotherapy. More than 50% of drugs against cancer were isolated from natural sources, such as Catharanthus roseus and epipodophyllotoxin, isolated from Podophyllum. The biggest challenge is to maximize the control of the disease, while minimizing morbidity and toxicity to the surrounding normal tissues. The Erythroxylum suberosum is a common plant in the Brazilian Cerrado biome and is popularly known as 'cabelo-de-negro'. The objective of this study was to evaluate the cytotoxic activity of Erythroxylum suberosum plant extracts of the Brazilian Cerrado biome associated with radiotherapy in human cell lines of oral and hypopharynx carcinomas. Cells were treated with aqueous, ethanolic and hexanic extracts of Erythroxylum suberosum and irradiated at 4 Gy, 6 Gy and 8 Gy. Cytotoxicity was evaluated by MTT assay and the absorbance was measured at 570 nm in a Beckman Counter reader. Cisplatin, standard chemotherapy, was used as positive control. The use of Erythroxylum suberosum extracts showed a possible radiosensitizing effect in vitro for head and neck cancer. The cytotoxicity effect in the cell lines was not selective and it is very similar to the effect of standard chemotherapy. The aqueous extract of Erythroxylum suberosum, combined with radiotherapy was the most cytotoxic extract to oral and hypopharynx carcinomas. (author)

  11. Cytotoxic effect of Erythroxylum suberosum combined with radiotherapy in head and neck cancer cell lines

    Energy Technology Data Exchange (ETDEWEB)

    Macedo, Taysa B.C.; Torres, Hianne M.; Yamamoto-Silva, Fernanda Paula; Silva, Maria Alves G. [Universidade Federal de Goias (UFG), Goiania, GO (Brazil). Escola de Odontologia; Elias, Silvia T.; Silveira, Damaris; Magalhaes, Perola O.; Lofrano-Porto, Adriana; Guerra, Eliete N.S., E-mail: elieteneves@unb.br [Universidade de Brasilia (UnB), Brasilia, DF (Brazil). Faculdade de Ciencias da Saude

    2016-01-15

    The mouth and oropharynx cancer is the 6{sup th} most common type of cancer in the world. The treatment may involve surgery, chemotherapy and radiotherapy. More than 50% of drugs against cancer were isolated from natural sources, such as Catharanthus roseus and epipodophyllotoxin, isolated from Podophyllum. The biggest challenge is to maximize the control of the disease, while minimizing morbidity and toxicity to the surrounding normal tissues. The Erythroxylum suberosum is a common plant in the Brazilian Cerrado biome and is popularly known as 'cabelo-de-negro'. The objective of this study was to evaluate the cytotoxic activity of Erythroxylum suberosum plant extracts of the Brazilian Cerrado biome associated with radiotherapy in human cell lines of oral and hypopharynx carcinomas. Cells were treated with aqueous, ethanolic and hexanic extracts of Erythroxylum suberosum and irradiated at 4 Gy, 6 Gy and 8 Gy. Cytotoxicity was evaluated by MTT assay and the absorbance was measured at 570 nm in a Beckman Counter reader. Cisplatin, standard chemotherapy, was used as positive control. The use of Erythroxylum suberosum extracts showed a possible radiosensitizing effect in vitro for head and neck cancer. The cytotoxicity effect in the cell lines was not selective and it is very similar to the effect of standard chemotherapy. The aqueous extract of Erythroxylum suberosum, combined with radiotherapy was the most cytotoxic extract to oral and hypopharynx carcinomas. (author)

  12. Cytotoxic Effect of Erythroxylum suberosum Combined with Radiotherapy in Head and Neck Cancer Cell Lines.

    Science.gov (United States)

    Macedo, Taysa B C; Elias, Silvia T; Torres, Hianne M; Yamamoto-Silva, Fernanda Paula; Silveira, Dâmaris; Magalhães, Pérola O; Lofrano-Porto, Adriana; Guerra, Eliete N S; Silva, Maria Alves G

    2016-01-01

    The mouth and oropharynx cancer is the 6th most common type of cancer in the world. The treatment may involve surgery, chemotherapy and radiotherapy. More than 50% of drugs against cancer were isolated from natural sources, such as Catharanthus roseus and epipodophyllotoxin, isolated from Podophyllum. The biggest challenge is to maximize the control of the disease, while minimizing morbidity and toxicity to the surrounding normal tissues. The Erythroxylum suberosum is a common plant in the Brazilian Cerrado biome and is popularly known as "cabelo-de-negro". The objective of this study was to evaluate the cytotoxic activity of Erythroxylum suberosum plant extracts of the Brazilian Cerrado biome associated with radiotherapy in human cell lines of oral and hypopharynx carcinomas. Cells were treated with aqueous, ethanolic and hexanic extracts of Erythroxylum suberosum and irradiated at 4 Gy, 6 Gy and 8 Gy. Cytotoxicity was evaluated by MTT assay and the absorbance was measured at 570 nm in a Beckman Counter reader. Cisplatin, standard chemotherapy, was used as positive control. The use of Erythroxylum suberosum extracts showed a possible radiosensitizing effect in vitro for head and neck cancer. The cytotoxicity effect in the cell lines was not selective and it is very similar to the effect of standard chemotherapy. The aqueous extract of Erythroxylum suberosum, combined with radiotherapy was the most cytotoxic extract to oral and hypopharynx carcinomas. PMID:27007356

  13. Cancer Cell Cytotoxicities of 1-(4-Substitutedbenzoyl-4-(4-chlorobenzhydrylpiperazine Derivatives

    Directory of Open Access Journals (Sweden)

    Mine Yarim

    2012-06-01

    Full Text Available A series of novel 1-(4-substitutedbenzoyl-4-(4-chlorobenzhydrylpiperazine derivatives 5ag was designed by a nucleophilic substitution reaction of 1-(4-chlorobenzhydrylpiperazine with various benzoyl chlorides and characterized by elemental analyses, IR and 1H nuclear magnetic resonance spectra. Cytotoxicity of the compounds was demonstrated on cancer cell lines from liver (HUH7, FOCUS, MAHLAVU, HEPG2, HEP3B, breast (MCF7, BT20, T47D, CAMA-1, colon (HCT-116, gastric (KATO-3 and endometrial (MFE-296 cancer cell lines. Time-dependent cytotoxicity analysis of compound 5a indicated the long-term in situ stability of this compound. All compounds showed significant cell growth inhibitory activity on the selected cancer cell lines.

  14. PROTECTIVE EFFECT OF MELATONIN ON NEURAL CELLS AGAINST THE CYTOTOXICITY OF OXYRADICALS

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Objective. To investigate the exact mechanism of melatonin to prohibit the apoptosis of neural cells induced by various kinds of cytotoxic agents.Methods. We used the methods of phase contrast microscopy, MTT assay and hoechst dye staining to check this mechanism in SKNSH and U251 cell lines.Results. Both 2mmol/L H2O2 and 0.5 μ mol/L amyloid β- protein (Aβ) induce these two cell lines die via apoptosis. Either melatonin or glutathione can significantly protect both cell lines. The protective effect of 10 μ mol/L melatonin is as same as that of 60 μ mol/L glutathione.Conclusion. Melatonin can partly inhibit the cytotoxicity of H2O2 and Aβ through its role as a free radical scavenger.

  15. Comparison of the cytotoxicity of cladribine and clofarabine when combined with fludarabine and busulfan in AML cells: enhancement of cytotoxicity with epigenetic modulators

    OpenAIRE

    Valdez, Benigno C.; Li, Yang; Murray, David; Ji, Jie; Liu, Yan; Popat, Uday; Champlin, Richard E.; Andersson, Borje S.

    2015-01-01

    Clofarabine (Clo), fludarabine (Flu) and busulfan (Bu) combinations are efficacious in hematopoietic stem cell transplantation (HSCT) for myeloid leukemia. We now determined if the more affordable drug cladribine (Clad) can provide a viable alternative to Clo, with or without panobinostat (Pano) and 5-aza-2′-deoxycytidine (DAC). Both [Clad+Flu+Bu] and [Clo+Flu+Bu] combinations showed synergistic cytotoxicity in KBM3/Bu2506, HL60 and OCI-AML3 cell lines. Cell exposure to these drug combination...

  16. NKG2D ligands mediate immunosurveillance of senescent cells.

    Science.gov (United States)

    Sagiv, Adi; Burton, Dominick G A; Moshayev, Zhana; Vadai, Ezra; Wensveen, Felix; Ben-Dor, Shifra; Golani, Ofra; Polic, Bojan; Krizhanovsky, Valery

    2016-02-01

    Cellular senescence is a stress response mechanism that limits tumorigenesis and tissue damage. Induction of cellular senescence commonly coincides with an immunogenic phenotype that promotes self-elimination by components of the immune system, thereby facilitating tumor suppression and limiting excess fibrosis during wound repair. The mechanisms by which senescent cells regulate their immune surveillance are not completely understood. Here we show that ligands of an activating Natural Killer (NK) cell receptor (NKG2D), MICA and ULBP2 are consistently up-regulated following induction of replicative senescence, oncogene-induced senescence and DNA damage - induced senescence. MICA and ULBP2 proteins are necessary for efficient NK-mediated cytotoxicity towards senescent fibroblasts. The mechanisms regulating the initial expression of NKG2D ligands in senescent cells are dependent on a DNA damage response, whilst continuous expression of these ligands is regulated by the ERK signaling pathway. In liver fibrosis, the accumulation of senescent activated stellate cells is increased in mice lacking NKG2D receptor leading to increased fibrosis. Overall, our results provide new insights into the mechanisms regulating the expression of immune ligands in senescent cells and reveal the importance of NKG2D receptor-ligand interaction in protecting against liver fibrosis. PMID:26878797

  17. Cytotoxicity of algae extracts on normal and malignant cells.

    Science.gov (United States)

    Bechelli, Jeremy; Coppage, Myra; Rosell, Karen; Liesveld, Jane

    2011-01-01

    Algae preparations are commonly used in alternative medicine. We examined the effects of algae extracts on normal hematopoietic cells and leukemia cells. Ethanol extracts were prepared of Dunaliella salina (Dun), Astaxanthin (Ast), Spirulina platensis (Spir), and Aphanizomenon flos-aquae (AFA). Cell viability effects were completed by Annexin staining. Ast and AFA inhibited HL-60 and MV-4-11 whereas Dun and Spir had no effect. Primary AML blasts demonstrated increased apoptosis in AFA. Primary CLL cells showed apoptosis at 24 hours after exposure to Dun, Ast, Spir, and AFA. High AFA concentrations decreased viability of normal marrow cells. Normal CD34+ viability was inhibited by Dun. Dun and AFA inhibited BFU-E, but all extracts inhibited CFU-GM. Cell-cycle analysis of AML cell lines showed G0/G1 arrest in the presence of AFA. These data suggest that algae extracts may inhibit AML cell lines and leukemia blasts, but they may also have potential inhibitory effects on normal hematopoiesis. PMID:23213541

  18. In Vitro Cytotoxicity and Phototoxicity Assessment of Acylglutamate Surfactants Using a Human Keratinocyte Cell Line

    OpenAIRE

    Abhay Kyadarkunte; Milind Patole; Varsha Pokharkar

    2014-01-01

    In the current study, human keratinocyte cell line was used as in vitro cell culture model to elucidate the effects of the fatty acid chain length of acylglutamate (amino acid-based surfactant) namely, sodium cocoyl glutamate, sodium lauroyl glutamate, and sodium myristoyl glutamate on their cytotoxicity and the ultraviolet B induced phototoxicity. The endpoint used to assess toxicity was a tetrazolium-based assay whereas, the phototoxic potential of acylglutamate surfactants was predicted u...

  19. Cytotoxic Effects of Tropodithietic Acid on Mammalian Clonal Cell Lines of Neuronal and Glial Origin

    OpenAIRE

    Heidi Wichmann; Farina Vocke; Thorsten Brinkhoff; Meinhard Simon; Christiane Richter-Landsberg

    2015-01-01

    The marine metabolite tropodithietic acid (TDA), produced by several Roseobacter clade bacteria, is known for its broad antimicrobial activity. TDA is of interest not only as a probiotic in aquaculture, but also because it might be of use as an antibacterial agent in non-marine or non-aquatic environments, and thus the potentially cytotoxic influences on eukaryotic cells need to be evaluated. The present study was undertaken to investigate its effects on cells of the mammalian nervous system,...

  20. Poly (D,L-lactide-co-glycolide) nanoparticles: Uptake by epithelial cells and cytotoxicity

    OpenAIRE

    J. H. Hamman; L. A. Nkabinde; Shoba-Zikhali, L.N.N.; Semete-Makokotlela, B.; Kalombo, L.; H. Swai; Grobler, A.

    2014-01-01

    Nanoparticles as drug delivery systems offer benefits such as protection of the encapsulated drug against degradation, site-specific targeting and prolonged blood circulation times. The aim of this study was to investigate nanoparticle uptake into Caco-2 cell monolayers, their co-localization within the lysosomal compartment and their cytotoxicity in different cell lines. Rhodamine-6G labelled poly(D,L-lactide-co-glycolide) (PLGA) nanoparticles were prepared by a double emulsion solvent evapo...

  1. Poly (D,L-lactide-co-glycolide) nanoparticles: uptake by epithelial cells and cytotoxicity

    OpenAIRE

    L. A. Nkabinde; Shoba-Zikhali, L.N.N.; Semete-Makokotlela, B.; Grobler, A.; J. H. Hamman

    2014-01-01

    Nanoparticles as drug delivery systems offer benefits such as protection of the encapsulated drug against degradation, site-specific targeting and prolonged blood circulation times. The aim of this study was to investigate nanoparticle uptake into Caco-2 cell monolayers, their co-localization within the lysosomal compartment and their cytotoxicity in different cell lines. Rhodamine-6G labelled poly(D,L-lactide-co-glycolide) (PLGA) nanoparticles were prepared by a double emulsion s...

  2. Cytotoxicity of Biologically Synthesized Silver Nanoparticles in MDA-MB-231 Human Breast Cancer Cells

    OpenAIRE

    Sangiliyandi Gurunathan; Jae Woong Han; Vasuki Eppakayala; Muniyandi Jeyaraj; Jin-Hoi Kim

    2013-01-01

    Silver nanoparticles (AgNPs) have been used as an antimicrobial and disinfectant agents. However, there is limited information about antitumor potential. Therefore, this study focused on determining cytotoxic effects of AgNPs on MDA-MB-231 breast cancer cells and its mechanism of cell death. Herein, we developed a green method for synthesis of AgNPs using culture supernatant of Bacillus funiculus, and synthesized AgNPs were characterized by various analytical techniques such as UV-visible spe...

  3. A role of ZnO nanoparticle electrostatic properties in cancer cell cytotoxicity

    Science.gov (United States)

    Wingett, Denise; Louka, Panagiota; Anders, Catherine B; Zhang, Jianhui; Punnoose, Alex

    2016-01-01

    ZnO nanoparticles (NPs) have previously been shown to exhibit selective cytotoxicity against certain types of cancerous cells suggesting their potential use in biomedical applications. In this study, we investigate the effect of surface modification of ZnO NPs on their cytotoxicity to both cancerous and primary T cells. Our results show that polyacrylic acid capping produces negatively charged ZnO NPs that are significantly more toxic compared to uncapped positively charged NPs of identical size and composition. In contrast, the greatest selectivity against cancerous cells relative to normal cells is observed with cationic NPs. In addition, differences in NP cytotoxicity inversely correlate with NP hydrodynamic size, propensity for aggregation, and dissolution profiles. The generation of reactive oxygen species (ROS) was also observed in the toxicity mechanism with anionic NPs generating higher levels of mitochondrial superoxide without appreciably affecting glutathione levels. Additional experiments evaluated the combined effects of charged ZnO NPs and nontoxic cationic or anionic CeO2 NPs. Results show that the CeO2 NPs offer protective effects against cytotoxicity from anionic ZnO NPs via antioxidant properties. Altogether, study data indicate that surface modification of NPs and resulting changes in their surface charge affect the level of intracellular ROS production, which can be ameliorated by the CeO2 ROS scavenger, suggesting that ROS generation is a dominant mechanism of ZnO NP cytotoxicity. These findings demonstrate the importance of surface electrostatic properties for controlling NP toxicity and illustrate an approach for engineering NPs with desired properties for potential use in biological applications. PMID:27486313

  4. Effect of Biophytum sensitivum on cell-mediated immune response in mice.

    Science.gov (United States)

    Guruvayoorappan, C; Kuttan, G

    2007-01-01

    Effect of Biophytum sensitivum on cell-mediated immune response was studied in normal as well as Ehrlich ascites tumor bearing BALB/c mice. Administration of Biophytum sensitivum significantly enhanced the proliferation of splenocytes, thymocytes and bone marrow cells by stimulating the mitogenic potential of various mitogens such as Lipopolysaccharide (LPS), Concanavalin A (Con A), Phytohaemagglutinin (PHA) and Poke Weed Mitogen (PWM). Natural killer (NK) cell activity was enhanced significantly by Biophytum sensitivum in both the normal (43.6% cell lysis on day 5) and the tumor bearing group (48.2% cell lysis on day 5), and it was found to be earlier than tumor bearing control animals (maximum of 13.4% cell lysis on day 9). Antibody dependent cellular cytotoxicity (ADCC) was also enhanced significantly in both Biophytum treated normal (35% cell lysis on day 7) as well as tumor bearing animals (40.2% cell lysis on day 7) compared to untreated control tumor bearing animals (maximum of 12.3% cell lysis on day 11). An early antibody dependent complement mediated cytotoxicity (ACC) was also observed in the Biophytum treated normal (22.6% cell lysis, on day 15) and tumor bearing animals (26.4% cell lysis, on day 15). Results of our present study suggest the immunomodulatory property of Biophytum sensitivum. PMID:18075848

  5. In vitro cytotoxicity of Indonesian stingless bee products against human cancer cell lines

    Institute of Scientific and Technical Information of China (English)

    Paula; M.Kustiawan; Songchan; Puthong; Enos; T.Arung; Chanpen; Chanchao

    2014-01-01

    Objective:To screen crude extracts of propolis,bee pollen and honey from four stingless bee species[Trigona incisa(T.incisa)],Timia apicalis,Trigona fuso-baltata and Trigona filscibasis)native to East Kalimantan.Indonesia for cytotoxic activity against five human cancer cell lines(HepG2,SW620,ChaGo-1,KATO-Ⅲand BT474).Methods:All samples were extracted with methanol,and then subpartitioned with n-hexane and ethyl acetate.Each crude extract was screened at 20μg/mL for in vitro cytotoxicity against the cell lines using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay.Tn addition,four previously shown bioactive components from propolis(apigenin,cafieic acid phenyl ester,kaempferol and naringenin)and two chemotherapeutic drugs(doxorubicin and 5-fluorouracil)were used to evaluate the sensitivity of the cell lines.Results:Overall,crude extracts from propolis and honey had higher cytotoxic activities than bee pollen,but the activity was dependent upon the extraction solvent,bee species and cell line.Propolis extracts from T.incisa and Tarda apicalis showed the highest and lowest cytotoxic activity,respectively.Only the HepG2 cell line was broadly sensitive to the honey extracts.For pure compounds,doxorubicin was the most cytotoxic,the four propolis compounds the least,but the ChaGo-I cell line was sensitive to kaempferol at 10μg/mL and KATO-Ⅲwas sensitive to kaempferol and apigenin at 10μg/mL,.All pure compounds were effective against the BT474 cell line.Conclusions:Propolis from f,incisa and Trigona fusco-balteata contain an in vitro cytotoxic activity against human cancer cell lines.Further study is required,including the isolation and characterization of the active antiproliferative agent(s).

  6. Chemical Characterization and in Vitro Cytotoxicity on Squamous Cell Carcinoma Cells of Carica papaya Leaf Extracts.

    Science.gov (United States)

    Nguyen, Thao T; Parat, Marie-Odile; Hodson, Mark P; Pan, Jenny; Shaw, Paul N; Hewavitharana, Amitha K

    2016-01-01

    In traditional medicine, Carica papaya leaf has been used for a wide range of therapeutic applications including skin diseases and cancer. In this study, we investigated the in vitro cytotoxicity of aqueous and ethanolic extracts of Carica papaya leaves on the human oral squamous cell carcinoma SCC25 cell line in parallel with non-cancerous human keratinocyte HaCaT cells. Two out of four extracts showed a significantly selective effect towards the cancer cells and were found to contain high levels of phenolic and flavonoid compounds. The chromatographic and mass spectrometric profiles of the extracts obtained with Ultra High Performance Liquid Chromatography-Quadrupole Time of Flight-Mass Spectrometry were used to tentatively identify the bioactive compounds using comparative analysis. The principal compounds identified were flavonoids or flavonoid glycosides, particularly compounds from the kaempferol and quercetin families, of which several have previously been reported to possess anticancer activities. These results confirm that papaya leaf is a potential source of anticancer compounds and warrant further scientific investigation to validate the traditional use of papaya leaf to treat cancer. PMID:26712788

  7. Chemical Characterization and in Vitro Cytotoxicity on Squamous Cell Carcinoma Cells of Carica Papaya Leaf Extracts

    Directory of Open Access Journals (Sweden)

    Thao T. Nguyen

    2015-12-01

    Full Text Available In traditional medicine, Carica papaya leaf has been used for a wide range of therapeutic applications including skin diseases and cancer. In this study, we investigated the in vitro cytotoxicity of aqueous and ethanolic extracts of Carica papaya leaves on the human oral squamous cell carcinoma SCC25 cell line in parallel with non-cancerous human keratinocyte HaCaT cells. Two out of four extracts showed a significantly selective effect towards the cancer cells and were found to contain high levels of phenolic and flavonoid compounds. The chromatographic and mass spectrometric profiles of the extracts obtained with Ultra High Performance Liquid Chromatography-Quadrupole Time of Flight-Mass Spectrometry were used to tentatively identify the bioactive compounds using comparative analysis. The principal compounds identified were flavonoids or flavonoid glycosides, particularly compounds from the kaempferol and quercetin families, of which several have previously been reported to possess anticancer activities. These results confirm that papaya leaf is a potential source of anticancer compounds and warrant further scientific investigation to validate the traditional use of papaya leaf to treat cancer.

  8. Armed and accurate: engineering cytotoxic T cells for eradication of leukemia

    Directory of Open Access Journals (Sweden)

    Radic Marko

    2012-02-01

    Full Text Available Abstract Translational medicine depends on a rapid and efficient exchange of results between the bench and the bedside. A recent example from the field of cancer immunotherapy highlights the essential nature of this exchange. Methods have been developed to convert a patient's cytotoxic T cells into efficient and specific killers of cancer cells in patients with leukemia. By using recombinant DNA techniques, a lentiviral vector was constructed to express chimeric antigen receptors in cytotoxic T cells from patients with advanced chronic lymphocytic leukemia. The purpose of the chimeric receptors was to direct the cytotoxic T cell activity against cells causing the cancer. The effect of infusing the engineered T cells back into the cancer patients was tested in a Phase I trial at the University of Pennsylvania, and the initial results were described in two articles from the research team of Dr. Carl June. The remarkable success of this trial should energize further applications of biotechnology in the development of new cancer immunotherapies.

  9. IN VITRO CYTOTOXICITY OF MADHUCA INDICA AGAINST DIFFERENT HUMAN CANCER CELL LINES

    Directory of Open Access Journals (Sweden)

    Satish K. Verma et al.

    2012-05-01

    Full Text Available Cancer is a public health problem all over the world. Large number of plants and their isolated constituents has been shown to potential anticancer activity. Ethanolic whole plant extract of Madhuca indica showed in vitro cytotoxicity against different human cancer cell lines such as lung, neuroblastima, and colon. There was no growth of inhibition recorded against liver cancer cell line. Sulforhodamine B dye (SRB assay was done for in vitro cytotoxicity test assay. The in vitro cytotoxicity was performed against five human cancer cell lines namely of lung (A-549, liver (Hep-2 colon (502713 HT-29 and neuroblastima (IMR-32. The activity was done using 100µg/ml of the extract. Against lung (A-549 cell line plant extract showed 83% growth of inhibition. In case of liver (Hep-2 showed no activity reported, where as in case of colon 502713 cell line plant extract showed maximum activity. In case of HT-29 liver human cancer line and IMR-32 neuroblastima cell line plant extract showed 99% and 98% activity respectively.

  10. Cytotoxicity and apoptotic effects of nickel oxide nanoparticles in cultured HeLa cells

    International Nuclear Information System (INIS)

    The aim of this study was to observe the cytotoxicity and apoptotic effects of nickel oxide nanoparticles on human cervix epithelioid carcinoma cell line (HeLa). Nickel oxide precursors were synthesized by an nickel sulphate-excess urea reaction in boiling aqueous solution. The synthesized NiO nanoparticles (< 200 nm) were investigated by X-ray diffraction analysis and transmission electron microscopy techniques. For cytotoxicity experiments, HeLa cells were incubated in 50-500 micro g/ml NiO for 2, 6, 12 and 16 hours. The viable cells were counted with a haemacytometer using light microscopy. The cytotoxicity was observed low in 50-200 micro g/ml concentration for 16 h, but high in 400-500 micro g/ml concentration for 2-6 h. HeLa cells cytoplasm membrane was lysed and detached from the well surface in 400 micro g/ml concentration NiO nanoparticles. Double staining and M30 immunostaining were performed to quantify the number of apoptotic cells in culture on the basis of apoptotic cell nuclei scores. The apoptotic effect was observed 20% for 16 h incubation. (authors)

  11. Cytotoxic activity of kenaf (Hibiscus cannabinus L.) seed extract and oil against human cancer cell lines

    Institute of Scientific and Technical Information of China (English)

    Yu Hua Wong; Wai Yan Tan; Chin Ping Tan; Kamariah Long; Kar Lin Nyam

    2014-01-01

    Objective: To examine the cytotoxic properties of both the kenaf (Hibiscus cannabinus L.) seed extract and kenaf seed oil on human cervical cancer, human breast cancer, human colon cancer and human lung cancer cell lines.Methods:kenaf seed oil on human cancer cell lines was evaluated by using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and sulforhodamine B assays. Cell morphological changes were observed by using an inverted light microscope.Results:The in vitro cytotoxic activity of the kenaf (Hibiscus cannabinus L.) seed extract and cancer cell lines. Morphological alterations in the cell lines after KSE and KSO treatment were observed. KSE and KSO possessed effective cytotoxic activities against all the cell lines been selected.Conclusions:KSE and KSO could be potential sources of natural anti-cancer agents. Further The kenaf seed extract (KSE) exhibited a lower IC50 than kenaf seed oil (KSO) in all of the investigations on using kenaf seeds for anti-proliferative properties are warranted.

  12. Cytotoxicity and apoptotic effects of nickel oxide nanoparticles in cultured HeLa cells

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    Kezban Ada

    2010-04-01

    Full Text Available The aim of this study was to observe the cytotoxicity and apoptotic effects of nickel oxide nanoparticles on humancervix epithelioid carcinoma cell line (HeLa. Nickel oxide precursors were synthesized by an nickel sulphate-excess ureareaction in boiling aqueous solution. The synthesized NiO nanoparticles (<200 nm were investigated by X-ray diffractionanalysis and transmission electron microscopy techniques. For cytotoxicity experiments, HeLa cells were incubated in50-500 μg/mL NiO for 2, 6, 12 and 16 hours. The viable cells were counted with a haemacytometer using light microscopy.The cytotoxicity was observed low in 50-200 μg/mL concentration for 16 h, but high in 400-500 μg/mL concentration for2-6 h. HeLa cells' cytoplasm membrane was lysed and detached from the well surface in 400 μg/mL concentration NiOnanoparticles. Double staining and M30 immunostaining were performed to quantify the number of apoptotic cells in cultureon the basis of apoptotic cell nuclei scores. The apoptotic effect was observed 20% for 16 h incubation.

  13. Uptake and cytotoxicity of chitosan nanoparticles in human liver cells

    International Nuclear Information System (INIS)

    Despite extensive research into the biomedical and pharmaceutical applications of nanoparticles, and the liver being the main detoxifying organ in the human body, there are limited studies which delineate the hepatotoxicity of nanoparticles. This paper reports on the biological interactions between liver cells and chitosan nanoparticles, which have been widely recognised as biocompatible. Using the MTT assay, human liver cells were shown to tolerate up to 4 h of exposure to 0.5% w/v of chitosan nanoparticles (18 ± 1 nm, 7.5 ± 1.0 mV in culture medium). At nanoparticle concentrations above 0.5% w/v, cell membrane integrity was compromised as evidenced by leakage of alanine transaminase into the extracellular milieu, and there was a dose-dependent increase in CYP3A4 enzyme activity. Uptake of chitosan nanoparticles into the cell nucleus was observed by confocal microscopic analysis after 4 h exposure with 1% w/v of chitosan nanoparticles. Electron micrographs further suggest necrotic or autophagic cell death, possibly caused by cell membrane damage and resultant enzyme leakage.

  14. Ethanolic Extract Cytotoxic Effect of Zingiber Afficinale in Breast Cancer (MCF7 Cell Line

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    J Tavakkol Afshari

    2010-07-01

    Full Text Available Introduction & Objective: Biological activities of Zingiber afficieale plants have been reported as possessing anticancer, antibacterial, anti ulcer, antifungal, and insecticidal properties. However, its antitumor effects haven't been studied in cancer cell lines. The aim of this study was to investigate the antitumor effect of zingiber afficieale on breast cancer cell lines. Materials & Methods: This experimental study was conducted in 2010 at Mashhad University of medical Sciences. Breast cancer cell line (MCF7 and normal connective tissue cell line (L929 were cultured in DMEM medium. Ethanolic extract of Zingiber afficinale was prepared and cell lines were treated with different concentration of extract (5000 to 78 µg. Cell viability was measured by MTT assay after 24, 48, and 72 hours. The collected data were statistically analyzed by SPSS software. Results: The effects of Zingiber afficinale on cell viability were observed after 48 hours on cell lines. Ginger doses in 2500 µg concentration inhibited 50% of cell growth (IC50 in cell lines after 48 hours. Conclusion: Our study revealed that fresh ginger extract has cytotoxic effects on tumor cells, but it doesn’t have any cytotoxic effect on normal cells. It seems that ginger could be considered as a promising chemotherapeutic agent in cancer treatment.

  15. Cytotoxic Activity of Piper cubeba Extract in Breast Cancer Cell Lines

    Science.gov (United States)

    Graidist, Potchanapond; Martla, Mananya; Sukpondma, Yaowapa

    2015-01-01

    This study aimed to evaluate the cytotoxicity of a crude extract of Piper cubeba against normal and breast cancer cell lines. To prepare the extract, P. cubeba seeds were ground, soaked in methanol and dichloromethane and isolated by column chromatography. Fractions were tested for cytotoxicity effects on normal fibroblast (L929), normal breast (MCF-12A) and breast cancer cell lines (MCF-7, MDA-MB-468 and MDA-MB-231). The most effective fraction was selected for DNA fragmentation assay to detect apoptotic activity. The results showed that the methanolic crude extract had a higher cytotoxic activity against MDA-MB-468 and MCF-7 than a dichloromethane crude extract. Then, the methanolic crude extract was separated into six fractions, designated A to F. Fraction C was highly active against breast cancer cell lines with an IC50 value less than 4 μg/mL. Therefore, Fraction C was further separated into seven fractions, CA to CG. The 1H-NMR profile showed that Fraction CE was long chain hydrocarbons. Moreover, Fraction CE demonstrated the highest activity against MCF-7 cells with an IC50 value of 2.69 ± 0.09 μg/mL and lower cytotoxicity against normal fibroblast L929 cells with an IC50 value of 4.17 ± 0.77 μg/mL. Finally, DNA fragmentation with a ladder pattern characteristic of apoptosis was observed in MCF-7, MDA-MB-468, MDA-MB-231 and L929 cells, but not in MCF-12A cells. PMID:25867951

  16. Cytotoxicity of Marchantia convoluta leaf extracts to human liver and lung cancer cells

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    Xiao J.B.

    2006-01-01

    Full Text Available The cytotoxicity of three extracts (petroleum ether, ethyl acetate and n-butanol from a plant used in folk medicine, Marchantia convoluta, to human non-small cell lung carcinoma (H1299 and liver carcinoma (HepG2 cell lines was tested. After 72-h incubation of lung and liver cancer cell cultures with varying concentrations of extracts (15 to 200 µg/mL, cytotoxicity was determined by the 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide assay and reported in terms of cell viability. The extracts that showed a significant cytotoxicity were subjected to gas chromatography-mass spectrometry analysis to identify the components. The ethyl acetate, but not the petroleum ether or n-butanol extract, had a significant cytotoxicity against lung and liver carcinoma cells with IC50 values of 100 and 30 µg/mL, respectively. A high concentration of ethyl acetate extract (100 µg/mL rapidly reduced the number of H1299 cells. At lower concentrations of ethyl acetate extract (15, 30, and 40 µg/mL, the numbers of HepG2 cells started to decrease markedly. Gas chromatography-mass spectrometry analysis of the ethyl acetate extract revealed the presence of several compounds such as phytol (23.42%, 1,2,4-tripropylbenzene (13.09%, 9-cedranone (12.75%, ledene oxide (7.22%, caryophyllene (1.82%, and caryophyllene oxide (1.15%. HPLC analysis result showed that there were no flavonoids in ethyl acetate extract, but flavonoids are abundant in n-butanol extract. Further studies are needed regarding the identification, toxicity, and mechanism of action of active compounds.

  17. T-Bet Mediated Anti-Neoplastic Effects of Dendritic Cell-Cytokine Induced Killer Cells in Vitro

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    Liu Miao

    2012-03-01

    Full Text Available Objective: To investigate the molecular mechanism underlying T-bet mediated anti-neoplastic effects of cytokine induced killer (CIK cells.Methods: Lymphocytes isolated from peripheral blood of leukemic children were induced with γ- interferon (IFN-γ, CD3McAb and interluki-2 (IL-2, and co-cultured with dendritic cells (DCs to generate DC-CIK cells. The morphology and immunophenotype of these cells were determined by a light microscopy and flow cytometry, respectively. IL-2 and IFN-γ levels released by DC-CIK cells were quantified by ELISA. Cytotoxicity of DC-CIK cells against leukemia cell lines was measured by MTT assay. FCM was used to detect CD4+CD25+Treg cells, while RT-PCR and Western blot were used to determine mRNA and protein expressions of Foxp3 and GATA3 in DC-CIK cells treated with T-bet monoclonal antibody.Findings: Induced DC-CIK cells were regular, round and transparent with variable cell volume and cellular aggregation. The main effector cells in this population were CD3+CD8+ cells and CD3+CD56+ cells. We demonstrated a time dependent increase in IL-2 and IFN-γ levels after induction. DC-CIK cells were cytotoxic to B95 cells, Jhhan cells and M07e cells, with the highest cytotoxicity towards B95 cells. Treatment with mouse anti-human T-bet monoclonal antibody resulted in an increase in the proportion of CD4+CD25+Treg cells and elevation of Foxp3 and GATA3 mRNA and protein levels.Conclusion: DC-CIK cells induced with cytokines were strongly cytotoxic towards a number of cancer cell lines. Foxp3 and GATA3 were implicated in the T-bet mediated anti-neoplastic effects of DC-CIK cells via activation of the Th1 pathway and suppression of the Th2 and Treg pathways.

  18. Manganese oxidation state mediates toxicity in PC12 cells

    International Nuclear Information System (INIS)

    The role of the manganese (Mn) oxidation state on cellular Mn uptake and toxicity is not well understood. Therefore, undifferentiated PC12 cells were exposed to 0-200 μM Mn(II)-chloride or Mn(III)-pyrophosphate for 24 h, after which cellular manganese levels were measured along with measures of cell viability, function, and cytotoxicity (trypan blue exclusion, medium lactate dehydrogenase (LDH), 8-isoprostanes, cellular ATP, dopamine, serotonin, H-ferritin, transferrin receptor (TfR), Mn-superoxide dismutase (MnSOD), and copper-zinc superoxide dismutase (CuZnSOD) protein levels). Exposures to Mn(III) >10 μM produced 2- to 5-fold higher cellular manganese levels than equimolar exposures to Mn(II). Cell viability and ATP levels both decreased at the highest Mn(II) and Mn(III) exposures (150-200 μM), while Mn(III) exposures produced increases in LDH activity at lower exposures (≥50 μM) than did Mn(II) (200 μM only). Mn(II) reduced cellular dopamine levels more than Mn(III), especially at the highest exposures (50% reduced at 200 μM Mn(II)). In contrast, Mn(III) produced a >70% reduction in cellular serotonin at all exposures compared to Mn(II). Different cellular responses to Mn(II) exposures compared to Mn(III) were also observed for H-ferritin, TfR, and MnSOD protein levels. Notably, these differential effects of Mn(II) versus Mn(III) exposures on cellular toxicity could not simply be accounted for by the different cellular levels of manganese. These results suggest that the oxidation state of manganese exposures plays an important role in mediating manganese cytotoxicity

  19. Cytotoxic Activities against Breast Cancer Cells of Local Justicia gendarussa Crude Extracts

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    Zahidah Ayob

    2014-01-01

    Full Text Available Justicia gendarussa methanolic leaf extracts from five different locations in the Southern region of Peninsular Malaysia and two flavonoids, kaempferol and naringenin, were tested for cytotoxic activity. Kaempferol and naringenin were two flavonoids detected in leaf extracts using gas chromatography-flame ionization detection (GC-FID. The results indicated that highest concentrations of kaempferol and naringenin were detected in leaves extracted from Mersing with 1591.80 mg/kg and 444.35 mg/kg, respectively. Positive correlations were observed between kaempferol and naringenin concentrations in all leaf extracts analysed with the Pearson method. The effects of kaempferol and naringenin from leaf extracts were examined on breast cancer cell lines (MDA-MB-231 and MDA-MB-468 using MTT assay. Leaf extract from Mersing showed high cytotoxicity against MDA-MB-468 and MDA-MB-231 with IC50 values of 23 μg/mL and 40 μg/mL, respectively, compared to other leaf extracts. Kaempferol possessed high cytotoxicity against MDA-MB-468 and MDA-MB-231 with IC50 values of 23 μg/mL and 34 μg/mL, respectively. These findings suggest that the presence of kaempferol in Mersing leaf extract contributed to high cytotoxicity of both MDA-MB-231 and MDA-MB-468 cancer cell lines.

  20. Cytotoxic and genotoxic effects of abamectin, chlorfenapyr, and imidacloprid on CHOK1 cells.

    Science.gov (United States)

    Al-Sarar, Ali S; Abobakr, Yasser; Bayoumi, Alaa E; Hussein, Hamdy I

    2015-11-01

    The cytotoxicity and genotoxicity of abamectin, chlorfenapyr, and imidacloprid have been evaluated on the Chinese hamster ovary (CHOK1) cells. Neutral red incorporation (NRI), total cellular protein content (TCP), and methyl tetrazolium (MTT) assays were followed to estimate the mid-point cytotoxicity values, NRI50, TCP50, and MTT50, respectively. The effects of the sublethal concentration (NRI25) on glutathione S-transferase (GST), glutathione reductase (GRD), glutathione peroxidase (GPX), and total glutathione content have been evaluated in the presence and absence of reduced glutathione (GSH), vitamin C, and vitamin E. The genotoxicity was evaluated using chromosomal aberrations (CA), micronucleus (MN) formation, and DNA fragmentation techniques in the presence and absence of the metabolic activation system, S9 mix. Abamectin was the most cytotoxic pesticide followed by chlorfenapyr, while imidacloprid was the least cytotoxic one. The glutathione redox cycle components were altered by the tested pesticides in the absence and presence of the tested antioxidants. The results of genotoxicity indicate that abamectin, chlorfenapyr, and imidacloprid have potential genotoxic effects on CHOK1 cells under the experimental conditions. PMID:26122579

  1. Particle Size Affects Concentration-Dependent Cytotoxicity of Chitosan Nanoparticles towards Mouse Hematopoietic Stem Cells

    Directory of Open Access Journals (Sweden)

    Siti Sarah Omar Zaki

    2015-01-01

    Full Text Available Chitosan nanoparticles (CSNPs have been extensively applied in medical and pharmaceutical fields as promising drug delivery systems. Despite that, the safety of CSNPs remains inadequate and needs further investigation, particularly on hematopoietic stem cells (HSCs. CSNPs were prepared by ionic gelation method and later were characterized for their physical characteristics (particle size and zeta potential. Cytotoxicity of CSNPs was assessed by MTT assay. Particle size was highly influenced by chitosan concentration and molecular weight (medium and high molecular weight (MMW and HMW. Higher chitosan concentration and molecular weight produced larger nanoparticles. Zeta potential of CSNPs was not significantly affected by chitosan concentrations and molecular weights used in the present study. MMW had a better stability than HMW CSNPs as their particle size and zeta potential were not significantly altered after autoclaving. Cytotoxicity of CSNPs was influenced by zeta potential and particle size. On the other hand, chitosan concentration and molecular weight indirectly influenced cytotoxicity by affecting particle size and zeta potential of CSNPs. In conclusion, cytotoxicity of CSNPs was mainly attributed to their physical characteristics and this opens a strategy to ensure the safety of CSNPs applications in stem cell technology.

  2. Cytotoxic Activities against Breast Cancer Cells of Local Justicia gendarussa Crude Extracts

    Science.gov (United States)

    Abd Samad, Azman; Jamil, Shajarahtunnur

    2014-01-01

    Justicia gendarussa methanolic leaf extracts from five different locations in the Southern region of Peninsular Malaysia and two flavonoids, kaempferol and naringenin, were tested for cytotoxic activity. Kaempferol and naringenin were two flavonoids detected in leaf extracts using gas chromatography-flame ionization detection (GC-FID). The results indicated that highest concentrations of kaempferol and naringenin were detected in leaves extracted from Mersing with 1591.80 mg/kg and 444.35 mg/kg, respectively. Positive correlations were observed between kaempferol and naringenin concentrations in all leaf extracts analysed with the Pearson method. The effects of kaempferol and naringenin from leaf extracts were examined on breast cancer cell lines (MDA-MB-231 and MDA-MB-468) using MTT assay. Leaf extract from Mersing showed high cytotoxicity against MDA-MB-468 and MDA-MB-231 with IC50 values of 23 μg/mL and 40 μg/mL, respectively, compared to other leaf extracts. Kaempferol possessed high cytotoxicity against MDA-MB-468 and MDA-MB-231 with IC50 values of 23 μg/mL and 34 μg/mL, respectively. These findings suggest that the presence of kaempferol in Mersing leaf extract contributed to high cytotoxicity of both MDA-MB-231 and MDA-MB-468 cancer cell lines. PMID:25574182

  3. Increased natural killer-cell mobilization and cytotoxicity during marital conflict.

    Science.gov (United States)

    Dopp, J M; Miller, G E; Myers, H F; Fahey, J L

    2000-03-01

    Natural killer (NK) cells are reproducibly mobilized into the circulation in response to intense physical exercise or acute psychological stress, and altered expression of adhesion molecules potentially contributes to NK-cell mobilization. Studies of leukocyte mobilization during acute stress have used psychological stressors which facilitate tight experimental control but have limited applicability to everyday life. We therefore used a laboratory model of marital conflict as an experientially meaningful acute stressor to elucidate relationships among conflict, cardiovascular reactivity, and altered leukocyte phenotype and function. Forty-one ethnically diverse, nondistressed, healthy married couples were asked to discuss a specific problem in their marriage for 15 min. Blood pressure and heart rate were measured before, during, and after the discussion, and blood was remotely drawn at the same time points to quantify numbers of specific leukocyte subsets, NK-cell adhesion molecule expression, and NK cytotoxicity. Couples responded to the conflict task with cardiovascular reactivity; increases in the percentages of circulating NK cells and CD8(+) T cells and decreases in the percentage of circulating CD4(+) T cells; decreases in the percentage of NK cells that express L-selectin; and increases in NK-cell cytotoxicity without a commensurate increase in per-cell cytotoxicity. Rapid downregulation or shedding of L-selectin (CD62L) from NK cells did not contribute to their mobilization during conflict. Instead, CD62L(-) NK cells were mobilized while CD62L(+) NK cells were selectively retained in the vascular marginating pool and/or in extravascular tissue. From a broader perspective, the data support the hypothesis that altered trafficking of specific leukocyte subsets is an integral component of the fight-or-flight response to an acute stressor. PMID:10729214

  4. Biocompatibility of various ferrite nanoparticles evaluate