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Sample records for arresting daughter cells

  1. Mechanisms of daughter cell-size control during cell division.

    Science.gov (United States)

    Kiyomitsu, Tomomi

    2015-05-01

    Daughter cell size is tightly regulated during cell division. In animal cells, the position of the anaphase spindle specifies the cell cleavage site to dictate the relative size of the daughter cells. Although spindle orientation is regulated by dynein-dependent cortical pulling forces exerted on astral microtubules in many cell types, it was unclear how these forces are precisely regulated to center or displace the spindle. Recently, intrinsic signals derived from chromosomes or spindle poles have been demonstrated to regulate dynein-dependent pulling forces in symmetrically dividing cells. Unexpectedly, myosin-dependent contractile forces have also been shown to control spindle position by altering the cellular boundaries during anaphase. In this review, I discuss how dynein- and myosin-dependent forces are coordinately regulated to control daughter cell size. PMID:25548067

  2. Primitive human hematopoietic cells give rise to differentially specified daughter cells upon their initial cell division.

    NARCIS (Netherlands)

    Giebel, B.; Zhang, T.; Beckmann, J.; Spanholtz, J.; Wernet, P.; Ho, A.; Punzel, M.

    2006-01-01

    It is often predicted that stem cells divide asymmetrically, creating a daughter cell that maintains the stem-cell capacity, and 1 daughter cell committed to differentiation. While asymmetric stem-cell divisions have been proven to occur in model organisms (eg, in Drosophila), it remains illusive wh

  3. Sonic Hedgehog Opposes Epithelial Cell Cycle Arrest

    OpenAIRE

    Fan, Hongran; Khavari, Paul A

    1999-01-01

    Stratified epithelium displays an equilibrium between proliferation and cell cycle arrest, a balance that is disrupted in basal cell carcinoma (BCC). Sonic hedgehog (Shh) pathway activation appears sufficient to induce BCC, however, the way it does so is unknown. Shh-induced epidermal hyperplasia is accompanied by continued cell proliferation in normally growth arrested suprabasal cells in vivo. Shh-expressing cells fail to exit S and G2/M phases in response to calcium-induced differentiation...

  4. ACE2 is required for daughter cell-specific G1 delay in Saccharomyces cerevisiae

    OpenAIRE

    Laabs, Tracy L.; Markwardt, David D.; Slattery, Matthew G.; Newcomb, Laura L.; Stillman, David J.; Heideman, Warren

    2003-01-01

    Saccharomyces cerevisiae cells reproduce by budding to yield a mother cell and a smaller daughter cell. Although both mother and daughter begin G1 simultaneously, the mother cell progresses through G1 more rapidly. Daughter cell G1 delay has long been thought to be due to a requirement for attaining a certain critical cell size before passing the commitment point in the cell cycle known as START. We present an alternative model in which the daughter cell-specific Ace2 ...

  5. Daughter cells of Saccharomyces cerevisiae from old mothers display a reduced life span

    OpenAIRE

    1994-01-01

    The yeast Saccharomyces cerevisiae typically divides asymmetrically to give a large mother cell and a smaller daughter cell. As mother cells become old, they enlarge and produce daughter cells that are larger than daughters derived from young mother cells. We found that occasional daughter cells were indistinguishable in size from their mothers, giving rise to a symmetric division. The frequency of symmetric divisions became greater as mother cells aged and reached a maximum occurrence of 30%...

  6. Cell cycle phases in the unequal mother/daughter cell cycles of Saccharomyces cerevisiae.

    OpenAIRE

    Brewer, B J; Chlebowicz-Sledziewska, E; Fangman, W L

    1984-01-01

    During cell division in the yeast Saccharomyces cerevisiae mother cells produce buds (daughter cells) which are smaller and have longer cell cycles. We performed experiments to compare the lengths of cell cycle phases in mothers and daughters. As anticipated from earlier indirect observations, the longer cell cycle time of daughter cells is accounted for by a longer G1 interval. The S-phase and the G2-phase are of the same duration in mother and daughter cells. An analysis of five isogenic st...

  7. Mitotic Exit and Separation of Mother and Daughter Cells

    OpenAIRE

    Weiss, Eric L

    2012-01-01

    Productive cell proliferation involves efficient and accurate splitting of the dividing cell into two separate entities. This orderly process reflects coordination of diverse cytological events by regulatory systems that drive the cell from mitosis into G1. In the budding yeast Saccharomyces cerevisiae, separation of mother and daughter cells involves coordinated actomyosin ring contraction and septum synthesis, followed by septum destruction. These events occur in precise and rapid sequence ...

  8. Daughter-specific transcription factors regulate cell size control in budding yeast.

    Directory of Open Access Journals (Sweden)

    Stefano Di Talia

    2009-10-01

    Full Text Available In budding yeast, asymmetric cell division yields a larger mother and a smaller daughter cell, which transcribe different genes due to the daughter-specific transcription factors Ace2 and Ash1. Cell size control at the Start checkpoint has long been considered to be a main regulator of the length of the G1 phase of the cell cycle, resulting in longer G1 in the smaller daughter cells. Our recent data confirmed this concept using quantitative time-lapse microscopy. However, it has been proposed that daughter-specific, Ace2-dependent repression of expression of the G1 cyclin CLN3 had a dominant role in delaying daughters in G1. We wanted to reconcile these two divergent perspectives on the origin of long daughter G1 times. We quantified size control using single-cell time-lapse imaging of fluorescently labeled budding yeast, in the presence or absence of the daughter-specific transcriptional regulators Ace2 and Ash1. Ace2 and Ash1 are not required for efficient size control, but they shift the domain of efficient size control to larger cell size, thus increasing cell size requirement for Start in daughters. Microarray and chromatin immunoprecipitation experiments show that Ace2 and Ash1 are direct transcriptional regulators of the G1 cyclin gene CLN3. Quantification of cell size control in cells expressing titrated levels of Cln3 from ectopic promoters, and from cells with mutated Ace2 and Ash1 sites in the CLN3 promoter, showed that regulation of CLN3 expression by Ace2 and Ash1 can account for the differential regulation of Start in response to cell size in mothers and daughters. We show how daughter-specific transcriptional programs can interact with intrinsic cell size control to differentially regulate Start in mother and daughter cells. This work demonstrates mechanistically how asymmetric localization of cell fate determinants results in cell-type-specific regulation of the cell cycle.

  9. Apoptosis and cell-cycle arrest in human and murine tumor cells are initiated by isoprenoids.

    Science.gov (United States)

    Mo, H; Elson, C E

    1999-04-01

    Diverse classes of phytochemicals initiate biological responses that effectively lower cancer risk. One class of phytochemicals, broadly defined as pure and mixed isoprenoids, encompasses an estimated 22,000 individual components. A representative mixed isoprenoid, gamma-tocotrienol, suppresses the growth of murine B16(F10) melanoma cells, and with greater potency, the growth of human breast adenocarcinoma (MCF-7) and human leukemic (HL-60) cells. beta-Ionone, a pure isoprenoid, suppresses the growth of B16 cells and with greater potency, the growth of MCF-7, HL-60 and human colon adenocarcinoma (Caco-2) cells. Results obtained with diverse cell lines differing in ras and p53 status showed that the isoprenoid-mediated suppression of growth is independent of mutated ras and p53 functions. beta-Ionone suppressed the growth of human colon fibroblasts (CCD-18Co) but only when present at three-fold the concentration required to suppress the growth of Caco-2 cells. The isoprenoids initiated apoptosis and, concomitantly arrested cells in the G1 phase of the cell cycle. Both suppress 3-hydroxy-3-methylglutaryl CoA reductase activity. beta-Ionone and lovastatin interfered with the posttranslational processing of lamin B, an activity essential to assembly of daughter nuclei. This interference, we postulate, renders neosynthesized DNA available to the endonuclease activities leading to apoptotic cell death. Lovastatin-imposed mevalonate starvation suppressed the glycosylation and translocation of growth factor receptors to the cell surface. As a consequence, cells were arrested in the G1 phase of the cell cycle. This rationale may apply to the isoprenoid-mediated G1-phase arrest of tumor cells. The additive and potentially synergistic actions of these isoprenoids in the suppression of tumor cell proliferation and initiation of apoptosis coupled with the mass action of the diverse isoprenoid constituents of plant products may explain, in part, the impact of fruit, vegetable

  10. The stringent response and cell cycle arrest in Escherichia coli.

    OpenAIRE

    Daniel J Ferullo; Lovett, Susan T.

    2008-01-01

    The bacterial stringent response, triggered by nutritional deprivation, causes an accumulation of the signaling nucleotides pppGpp and ppGpp. We characterize the replication arrest that occurs during the stringent response in Escherichia coli. Wild type cells undergo a RelA-dependent arrest after treatment with serine hydroxamate to contain an integer number of chromosomes and a replication origin-to-terminus ratio of 1. The growth rate prior to starvation determines the number of chromosomes...

  11. The Stringent Response and Cell Cycle Arrest in Escherichia coli

    OpenAIRE

    Daniel J Ferullo; Lovett, Susan T.

    2008-01-01

    The bacterial stringent response, triggered by nutritional deprivation, causes an accumulation of the signaling nucleotides pppGpp and ppGpp. We characterize the replication arrest that occurs during the stringent response in Escherichia coli. Wild type cells undergo a RelA-dependent arrest after treatment with serine hydroxamate to contain an integer number of chromosomes and a replication origin-to-terminus ratio of 1. The growth rate prior to starvation determines the number of chromosomes...

  12. Asymmetric Inheritance of Mother Versus Daughter Centrosome in Stem Cell Division

    OpenAIRE

    Yamashita, Yukiko M.; Anthony P Mahowald; Perlin, Julie R.; Fuller, Margaret T.

    2007-01-01

    Adult stem cells often divide asymmetrically to produce one self-renewed stem cell and one differentiating cell, thus maintaining both populations. The asymmetric outcome of stem cell divisions can be specified by an oriented spindle and local self-renewal signals from the stem cell niche. Here we show that developmentally programmed asymmetric behavior and inheritance of mother and daughter centrosomes underlies the stereotyped spindle orientation and asymmetric outcome of stem cell division...

  13. The stringent response and cell cycle arrest in Escherichia coli.

    Science.gov (United States)

    Ferullo, Daniel J; Lovett, Susan T

    2008-12-01

    The bacterial stringent response, triggered by nutritional deprivation, causes an accumulation of the signaling nucleotides pppGpp and ppGpp. We characterize the replication arrest that occurs during the stringent response in Escherichia coli. Wild type cells undergo a RelA-dependent arrest after treatment with serine hydroxamate to contain an integer number of chromosomes and a replication origin-to-terminus ratio of 1. The growth rate prior to starvation determines the number of chromosomes upon arrest. Nucleoids of these cells are decondensed; in the absence of the ability to synthesize ppGpp, nucleoids become highly condensed, similar to that seen after treatment with the translational inhibitor chloramphenicol. After induction of the stringent response, while regions corresponding to the origins of replication segregate, the termini remain colocalized in wild-type cells. In contrast, cells arrested by rifampicin and cephalexin do not show colocalized termini, suggesting that the stringent response arrests chromosome segregation at a specific point. Release from starvation causes rapid nucleoid reorganization, chromosome segregation, and resumption of replication. Arrest of replication and inhibition of colony formation by ppGpp accumulation is relieved in seqA and dam mutants, although other aspects of the stringent response appear to be intact. We propose that DNA methylation and SeqA binding to non-origin loci is necessary to enforce a full stringent arrest, affecting both initiation of replication and chromosome segregation. This is the first indication that bacterial chromosome segregation, whose mechanism is not understood, is a step that may be regulated in response to environmental conditions. PMID:19079575

  14. The stringent response and cell cycle arrest in Escherichia coli.

    Directory of Open Access Journals (Sweden)

    Daniel J Ferullo

    2008-12-01

    Full Text Available The bacterial stringent response, triggered by nutritional deprivation, causes an accumulation of the signaling nucleotides pppGpp and ppGpp. We characterize the replication arrest that occurs during the stringent response in Escherichia coli. Wild type cells undergo a RelA-dependent arrest after treatment with serine hydroxamate to contain an integer number of chromosomes and a replication origin-to-terminus ratio of 1. The growth rate prior to starvation determines the number of chromosomes upon arrest. Nucleoids of these cells are decondensed; in the absence of the ability to synthesize ppGpp, nucleoids become highly condensed, similar to that seen after treatment with the translational inhibitor chloramphenicol. After induction of the stringent response, while regions corresponding to the origins of replication segregate, the termini remain colocalized in wild-type cells. In contrast, cells arrested by rifampicin and cephalexin do not show colocalized termini, suggesting that the stringent response arrests chromosome segregation at a specific point. Release from starvation causes rapid nucleoid reorganization, chromosome segregation, and resumption of replication. Arrest of replication and inhibition of colony formation by ppGpp accumulation is relieved in seqA and dam mutants, although other aspects of the stringent response appear to be intact. We propose that DNA methylation and SeqA binding to non-origin loci is necessary to enforce a full stringent arrest, affecting both initiation of replication and chromosome segregation. This is the first indication that bacterial chromosome segregation, whose mechanism is not understood, is a step that may be regulated in response to environmental conditions.

  15. Carbamazepine induces mitotic arrest in mammalian Vero cells

    International Nuclear Information System (INIS)

    We reported recently that the anticonvulsant drug carbamazepine, at supratherapeutic concentrations, exerts antiproliferative effects in mammalian Vero cells, but the underlying mechanism has not been elucidated. This motivates us to examine rigorously whether growth arrest was associated with structural changes in cellular organization during mitosis. In the present work, we found that exposure of the cells to carbamazepine led to an increase in mitotic index, mainly due to the sustained block at the metaphase/anaphase boundary, with the consequent inhibition of cell proliferation. Indirect immunofluorescence, using antibodies directed against spindle apparatus proteins, revealed that mitotic arrest was associated with formation of monopolar spindles, caused by impairment of centrosome separation. The final consequence of the spindle defects induced by carbamazepine, depended on the duration of cell cycle arrest. Following the time course of accumulation of metaphase and apoptotic cells during carbamazepine treatments, we observed a causative relationship between mitotic arrest and induction of cell death. Conversely, cells released from the block of metaphase by removal of the drug, continued to progress through mitosis and resume normal proliferation. Our results show that carbamazepine shares a common antiproliferative mechanism with spindle-targeted drugs and contribute to a better understanding of the cytostatic activity previously described in Vero cells. Additional studies are in progress to extend these initial findings that define a novel mode of action of carbamazepine in cultured mammalian cells

  16. Carbamazepine induces mitotic arrest in mammalian Vero cells

    Energy Technology Data Exchange (ETDEWEB)

    Perez Martin, J.M.; Fernandez Freire, P.; Labrador, V. [Departamento de Biologia, Facultad de Ciencias, Universidad Autonoma de Madrid, Cantoblanco, 28049 Madrid (Spain); Hazen, M.J. [Departamento de Biologia, Facultad de Ciencias, Universidad Autonoma de Madrid, Cantoblanco, 28049 Madrid (Spain)], E-mail: mariajose.hazen@uam.es

    2008-01-01

    We reported recently that the anticonvulsant drug carbamazepine, at supratherapeutic concentrations, exerts antiproliferative effects in mammalian Vero cells, but the underlying mechanism has not been elucidated. This motivates us to examine rigorously whether growth arrest was associated with structural changes in cellular organization during mitosis. In the present work, we found that exposure of the cells to carbamazepine led to an increase in mitotic index, mainly due to the sustained block at the metaphase/anaphase boundary, with the consequent inhibition of cell proliferation. Indirect immunofluorescence, using antibodies directed against spindle apparatus proteins, revealed that mitotic arrest was associated with formation of monopolar spindles, caused by impairment of centrosome separation. The final consequence of the spindle defects induced by carbamazepine, depended on the duration of cell cycle arrest. Following the time course of accumulation of metaphase and apoptotic cells during carbamazepine treatments, we observed a causative relationship between mitotic arrest and induction of cell death. Conversely, cells released from the block of metaphase by removal of the drug, continued to progress through mitosis and resume normal proliferation. Our results show that carbamazepine shares a common antiproliferative mechanism with spindle-targeted drugs and contribute to a better understanding of the cytostatic activity previously described in Vero cells. Additional studies are in progress to extend these initial findings that define a novel mode of action of carbamazepine in cultured mammalian cells.

  17. Cdc20 control of cell fate during prolonged mitotic arrest

    DEFF Research Database (Denmark)

    Nilsson, Jakob

    2011-01-01

    The fate of cells arrested in mitosis by antimitotic compounds is complex but is influenced by competition between pathways promoting cell death and pathways promoting mitotic exit. As components of both of these pathways are regulated by Cdc20-dependent degradation, I hypothesize that variations...

  18. Cell cycle control after DNA damage: arrest, recovery and adaptation

    International Nuclear Information System (INIS)

    DNA damage triggers surveillance mechanisms, the DNA checkpoints, that control the genome integrity. The DNA checkpoints induce several responses, either cellular or transcriptional, that favor DNA repair. In particular, activation of the DNA checkpoints inhibits cell cycle progression in all phases, depending on the stage when lesions occur. These arrests are generally transient and cells ultimately reenter the cell division cycle whether lesions have been repaired (this process is termed 'recovery') or have proved un-repairable (this option is called 'adaptation'). The mechanisms controlling cell cycle arrests, recovery and adaptation are largely conserved among eukaryotes, and much information is now available for the yeast Saccharomyces cerevisiae, that is used as a model organism in these studies. (author)

  19. Bacillus thuringiensis peptidoglycan hydrolase SleB171 involved in daughter cell separation during cell division.

    Science.gov (United States)

    Li, Hua; Hu, Penggao; Zhao, Xiuyun; Yu, Ziniu; Li, Lin

    2016-04-01

    Whole-genome analyses have revealed a putative cell wall hydrolase gene (sleB171) that constitutes an operon with two other genes (ypeBandyhcN) of unknown function inBacillus thuringiensisBMB171. The putative SleB171 protein consists of 259 amino acids and has a molecular weight of 28.3 kDa. Gene disruption ofsleB171in the BMB171 genome causes the formation of long cell chains during the vegetative growth phase and delays spore formation and spore release, although it has no significant effect on cell growth and the ultimate release of the spores. The inseparable vegetative cells were nearly restored through the complementation ofsleB171expression. Real-time quantitative polymerase chain reaction analysis revealed thatsleB171is mainly active in the vegetative growth phase, with a maximum activity at the early stationary growth phase. Western blot analysis also confirmed thatsleB171is preferentially expressed during the vegetative growth phase. These results demonstrated that SleB171 plays an essential role in the daughter cell separation during cell division. PMID:26922318

  20. Positioning of the NOR-bearing chromosomes in relation to nucleoli in daughter cells after mitosis

    Czech Academy of Sciences Publication Activity Database

    Kalmárová, Markéta; Smirnov, Evgeny; Kováčik, Lubomír; Popov, Alexey; Raška, Ivan

    2008-01-01

    Roč. 57, č. 3 (2008), s. 421-425. ISSN 0862-8408 R&D Projects: GA ČR(CZ) GA304/06/1691 Grant ostatní: GA ČR(CZ) GA304/06/1662; GA MŠk(CZ) LC535; Wellcome Trust(XE) 075834/04/Z Institutional research plan: CEZ:AV0Z50110509 Keywords : chromosome positioning * NORs * daughter cells Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.653, year: 2008

  1. Difference of cell cycle arrests induced by lidamycin in human breast cancer cells.

    Science.gov (United States)

    Liu, Xia; He, Hongwei; Feng, Yun; Zhang, Min; Ren, Kaihuan; Shao, Rongguang

    2006-02-01

    Lidamycin (LDM) is a member of the enediyne antibiotic family. It is undergoing phase I clinical trials in China as a potential chemotherapeutic agent. In the present study, we investigated the mechanism by which LDM induced cell cycle arrest in human breast cancer cells. The results showed that LDM induced G1 arrest in p53 wild-type MCF-7 cells at low concentrations, and caused both G1 and G2/M arrests at higher concentrations. In contrast, LDM induced only G2/M arrest in p53-mutant MCF-7/DOX cells. Western blotting analysis indicated that LDM-induced G1 and G2/M arrests in MCF-7 cells were associated with an increase of p53 and p21, and a decrease of phosphorylated retinoblastoma tumor suppressor protein, cyclin-dependent kinase (Cdk), Cdc2 and cyclin B1 protein levels. However, LDM-induced G2/M arrest in MCF-7/DOX cells was correlated with the reduction of cyclin B1 expression. Further study indicated that the downregulation of cyclin B1 by LDM in MCF-7 cells was associated with decreasing cyclin B1 mRNA levels and promoting protein degradation, whereas it was only due to inducing cyclin B1 protein degradation in MCF-7/DOX cells. In addition, activation of checkpoint kinases Chk1 or Chk2 maybe contributed to LDM-induced cell cycle arrest. Taken together, we provide the first evidence that LDM induces different cell cycle arrests in human breast cancer cells, which are dependent on drug concentration and p53 status. These findings are helpful in understanding the molecular anti-cancer mechanisms of LDM and support its clinical trials. PMID:16428935

  2. Cell cycle arrest and cell survival induce reverse trends of cardiolipin remodeling.

    Directory of Open Access Journals (Sweden)

    Yu-Jen Chao

    Full Text Available Cell survival from the arrested state can be a cause of the cancer recurrence. Transition from the arrest state to the growth state is highly regulated by mitochondrial activity, which is related to the lipid compositions of the mitochondrial membrane. Cardiolipin is a critical phospholipid for the mitochondrial integrity and functions. We examined the changes of cardiolipin species by LC-MS in the transition between cell cycle arrest and cell reviving in HT1080 fibrosarcoma cells. We have identified 41 cardiolipin species by MS/MS and semi-quantitated them to analyze the detailed changes of cardiolipin species. The mass spectra of cardiolipin with the same carbon number form an envelope, and the C64, C66, C68, C70 C72 and C74 envelopes in HT1080 cells show a normal distribution in the full scan mass spectrum. The cardiolipin quantity in a cell decreases while entering the cell cycle arrest, but maintains at a similar level through cell survival. While cells awakening from the arrested state and preparing itself for replication, the groups with short acyl chains, such as C64, C66 and C68 show a decrease of cardiolipin percentage, but the groups with long acyl chains, such as C70 and C72 display an increase of cardiolipin percentage. Interestingly, the trends of the cardiolipin species changes during the arresting state are completely opposite to cell growing state. Our results indicate that the cardiolipin species shift from the short chain to long chain cardiolipin during the transition from cell cycle arrest to cell progression.

  3. Complex Systems Analysis of Arrested Neural Cell Differentiation during Development and Analogous Cell Cycling Models in Carcinogenesis

    OpenAIRE

    Baianu, Professor I.C.; Prisecaru, M.S. V

    2004-01-01

    A new approach to the modular, complex systems analysis of nonlinear dynamics of arrested neural cell Differentiation--induced cell proliferation during organismic development and the analogous cell cycling network transformations involved in carcinogenesis is proposed. Neural tissue arrested differentiation that induces cell proliferation during perturbed development and Carcinogenesis are complex processes that involve dynamically inter-connected biomolecules in the intercellular, membrane...

  4. Mechanisms involved in alternariol-induced cell cycle arrest

    International Nuclear Information System (INIS)

    Alternariol (AOH), a mycotoxin produced by Alternaria sp, is often found as a contaminant in fruit and cereal products. Here we employed the murine macrophage cell line RAW 264.7 to test the hypothesis that AOH causes toxicity as a response to DNA damage. AOH at concentrations of 15–30 μM almost completely blocked cell proliferation. Within 30 min treatment, AOH (30 μM) significantly increased the level of reactive oxygen species (ROS). Furthermore, DNA base oxidations as well as DNA strand breaks and/or alkaline labile sites were detected by the comet assay after 2 h exposure of AOH. Cell death (mostly necrosis) was observed after prolonged exposure to the highest concentration of AOH (60 μM for 24 and 48 h) in our study. The DNA damage response involved phosphorylation (activation) of histone H2AX and check point kinase-1- and 2 (Chk-1/2). Moreover, AOH activated p53 and increased the expression of p21, Cyclin B, MDM2, and Sestrin 2; likewise the level of several miRNA was affected. AOH-induced Sestrin 2 expression was regulated by p53 and could at least partly be inhibited by antioxidants, suggesting a role of ROS in the response. Interestingly, the addition of antioxidants did not inhibit cell cycle arrest. Although the formation of ROS by itself was not directly linked cell proliferation, AOH-induced DNA damage and resulting transcriptional changes in p21, MDM2, and Cyclin B likely contribute to the reduced cell proliferation; while Sestrin 2 would contribute to the oxidant defense.

  5. Mechanisms involved in alternariol-induced cell cycle arrest

    Energy Technology Data Exchange (ETDEWEB)

    Solhaug, A., E-mail: Anita.Solhaug@vetinst.no [Norwegian Veterinary Institute, Oslo (Norway); Vines, L.L. [Michigan State University, Department of Food Science and Human Nutrition, East Lansing, MI (United States); Ivanova, L.; Spilsberg, B. [Norwegian Veterinary Institute, Oslo (Norway); Holme, J.A. [Norwegian Institute of Public Health, Division of Environmental Medicine, Oslo (Norway); Pestka, J. [Michigan State University, Department of Food Science and Human Nutrition, East Lansing, MI (United States); Collins, A. [University of Oslo, Department of Nutrition, Faculty of Medicine, Oslo (Norway); Eriksen, G.S. [Norwegian Veterinary Institute, Oslo (Norway)

    2012-10-15

    Alternariol (AOH), a mycotoxin produced by Alternaria sp, is often found as a contaminant in fruit and cereal products. Here we employed the murine macrophage cell line RAW 264.7 to test the hypothesis that AOH causes toxicity as a response to DNA damage. AOH at concentrations of 15-30 {mu}M almost completely blocked cell proliferation. Within 30 min treatment, AOH (30 {mu}M) significantly increased the level of reactive oxygen species (ROS). Furthermore, DNA base oxidations as well as DNA strand breaks and/or alkaline labile sites were detected by the comet assay after 2 h exposure of AOH. Cell death (mostly necrosis) was observed after prolonged exposure to the highest concentration of AOH (60 {mu}M for 24 and 48 h) in our study. The DNA damage response involved phosphorylation (activation) of histone H2AX and check point kinase-1- and 2 (Chk-1/2). Moreover, AOH activated p53 and increased the expression of p21, Cyclin B, MDM2, and Sestrin 2; likewise the level of several miRNA was affected. AOH-induced Sestrin 2 expression was regulated by p53 and could at least partly be inhibited by antioxidants, suggesting a role of ROS in the response. Interestingly, the addition of antioxidants did not inhibit cell cycle arrest. Although the formation of ROS by itself was not directly linked cell proliferation, AOH-induced DNA damage and resulting transcriptional changes in p21, MDM2, and Cyclin B likely contribute to the reduced cell proliferation; while Sestrin 2 would contribute to the oxidant defense.

  6. Growth arrest and differentiation-associated phosphoproteins in mesenchymal stem cells

    International Nuclear Information System (INIS)

    Cancer is thought to result from the expression of defects in the control of both cell proliferation and differentiation. In murine mesenchymal stem cells they have established that differentiation and proliferation can be mediated at a variety of distinct states in the G1 phase of the cell cycle. In order to evaluate the role of cellular phosphoprotein (PP) expression in these regulatory processes, five different growth and differentiation-dependent states were compared. Cells in the following states were studied: (1) exponential growth; (2) arrest in serum-deficient medium; (3) arrest at the predifferentiation arrest state; (4) arrest at a state of nonterminal differentiation; and (5) arrest at a state of terminal differentiation. Whole cell lysates from each group were phosphorylated in vitro using [γ-32P]ATP and analyzed by SDS-polyacrylamide gel electrophoresis. Two most interesting observations were established. First, a distinct PP with a molecular weight of 37 kD was expressed in all growth arrested cells but was not evident in rapidly growing cells. Second, two distinct differentiation-associated PP with molecular weights of 72 kD and 29 kD were expressed exclusively in nonterminally and terminally differentiated cells. Since the identification of the 37 kD cell cycle-dependent growth arrest-associated PP could be of great significance, they plan to further investigate the functional role of this phosphoprotein in the control of cellular proliferation

  7. TGEV nucleocapsid protein induces cell cycle arrest and apoptosis through activation of p53 signaling

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Li [College of Veterinary Medicine, Northwest A and F University, Yangling, Shaanxi 712100 (China); College of Life Sciences, Hainan Normal University, Haikou, Hainan 571158 (China); Huang, Yong; Du, Qian; Dong, Feng; Zhao, Xiaomin; Zhang, Wenlong; Xu, Xingang [College of Veterinary Medicine, Northwest A and F University, Yangling, Shaanxi 712100 (China); Tong, Dewen, E-mail: dwtong@nwsuaf.edu.cn [College of Veterinary Medicine, Northwest A and F University, Yangling, Shaanxi 712100 (China)

    2014-03-07

    Highlights: • TGEV N protein reduces cell viability by inducing cell cycle arrest and apoptosis. • TGEV N protein induces cell cycle arrest and apoptosis by regulating p53 signaling. • TGEV N protein plays important roles in TGEV-induced cell cycle arrest and apoptosis. - Abstract: Our previous studies showed that TGEV infection could induce cell cycle arrest and apoptosis via activation of p53 signaling in cultured host cells. However, it is unclear which viral gene causes these effects. In this study, we investigated the effects of TGEV nucleocapsid (N) protein on PK-15 cells. We found that TGEV N protein suppressed cell proliferation by causing cell cycle arrest at the S and G2/M phases and apoptosis. Characterization of various cellular proteins that are involved in regulating cell cycle progression demonstrated that the expression of N gene resulted in an accumulation of p53 and p21, which suppressed cyclin B1, cdc2 and cdk2 expression. Moreover, the expression of TGEV N gene promoted translocation of Bax to mitochondria, which in turn caused the release of cytochrome c, followed by activation of caspase-3, resulting in cell apoptosis in the transfected PK-15 cells following cell cycle arrest. Further studies showed that p53 inhibitor attenuated TGEV N protein induced cell cycle arrest at S and G2/M phases and apoptosis through reversing the expression changes of cdc2, cdk2 and cyclin B1 and the translocation changes of Bax and cytochrome c induced by TGEV N protein. Taken together, these results demonstrated that TGEV N protein might play an important role in TGEV infection-induced p53 activation and cell cycle arrest at the S and G2/M phases and apoptosis occurrence.

  8. SPARC expression induces cell cycle arrest via STAT3 signaling pathway in medulloblastoma cells

    Energy Technology Data Exchange (ETDEWEB)

    Chetty, Chandramu [Department of Cancer Biology and Pharmacology, University of Illinois College of Medicine at Peoria, One Illini Drive, Peoria, IL-61605 (United States); Dontula, Ranadheer [Section of Hematology/Oncology, Department of Medicine, University of Illinois College of Medicine at Chicago, 840 South Wood Street, Suite 820-E, Chicago, IL-60612 (United States); Ganji, Purnachandra Nagaraju [Department of Cancer Biology and Pharmacology, University of Illinois College of Medicine at Peoria, One Illini Drive, Peoria, IL-61605 (United States); Gujrati, Meena [Department of Pathology, University of Illinois College of Medicine at Peoria, One Illini Drive, Peoria, IL-61605 (United States); Lakka, Sajani S., E-mail: slakka@uic.edu [Section of Hematology/Oncology, Department of Medicine, University of Illinois College of Medicine at Chicago, 840 South Wood Street, Suite 820-E, Chicago, IL-60612 (United States)

    2012-01-13

    Highlights: Black-Right-Pointing-Pointer Ectopic expression of SPARC impaired cell proliferation in medulloblastoma cells. Black-Right-Pointing-Pointer SPARC expression induces STAT3 mediated cell cycle arrest in medulloblastoma cells. Black-Right-Pointing-Pointer SPARC expression significantly inhibited pre-established tumor growth in nude-mice. -- Abstract: Dynamic cell interaction with ECM components has profound influence in cancer progression. SPARC is a component of the ECM, impairs the proliferation of different cell types and modulates tumor cell aggressive features. We previously reported that SPARC expression significantly impairs medulloblastoma tumor growth in vivo. In this study, we demonstrate that expression of SPARC inhibits medulloblastoma cell proliferation. MTT assay indicated a dose-dependent reduction in tumor cell proliferation in adenoviral mediated expression of SPARC full length cDNA (Ad-DsRed-SP) in D425 and UW228 cells. Flow cytometric analysis showed that Ad-DsRed-SP-infected cells accumulate in the G2/M phase of cell cycle. Further, immunoblot and immunoprecipitation analyses revealed that SPARC induced G2/M cell cycle arrest was mediated through inhibition of the Cyclin-B-regulated signaling pathway involving p21 and Cdc2 expression. Additionally, expression of SPARC decreased STAT3 phosphorylation at Tyr-705; constitutively active STAT3 expression reversed SPARC induced G2/M arrest. Ad-DsRed-SP significantly inhibited the pre-established orthotopic tumor growth and tumor volume in nude-mice. Immunohistochemical analysis of tumor sections from mice treated with Ad-DsRed-SP showed decreased immunoreactivity for pSTAT3 and increased immunoreactivity for p21 compared to tumor section from mice treated with mock and Ad-DsRed. Taken together our studies further reveal that STAT3 plays a key role in SPARC induced G2/M arrest in medulloblastoma cells. These new findings provide a molecular basis for the mechanistic understanding of the

  9. Acanthamoeba induces cell-cycle arrest in host cells

    OpenAIRE

    Sissons, J.; Alsam, S.; Jayasekera, S.; Kim, K S; Stins, M; Khan, Naveed Ahmed

    2004-01-01

    Acanthamoeba can cause fatal granulomatous amoebic encephalitis (GAE) and eye keratitis. However, the pathogenesis and pathophysiology of these emerging diseases remain unclear. In this study, the effects of Acanthamoeba on the host cell cycle using human brain microvascular endothelial cells (HBMEC) and human corneal epithelial cells (HCEC) were determined. Two isolates of Acanthamoeba belonging to the T1 genotype (GAE isolate) and T4 genotype (keratitis isolate) were used, which showed seve...

  10. The Oxygen-Rich Postnatal Environment Induces Cardiomyocyte Cell-Cycle Arrest through DNA Damage Response

    OpenAIRE

    Bao\\xa0N. Puente; Wataru Kimura; Shalini\\xa0A. Muralidhar; Jesung Moon; James\\xa0F. Amatruda; Kate\\xa0L. Phelps; David Grinsfelder; Beverly\\xa0A. Rothermel; Rui Chen; Joseph\\xa0A. Garcia; Celio\\xa0X. Santos; SuWannee Thet; Eiichiro Mori; Michael\\xa0T. Kinter; Paul\\xa0M. Rindler

    2014-01-01

    The mammalian heart has a remarkable regenerative capacity for a short period of time after birth, after which the majority of cardiomyocytes permanently exit cell cycle. We sought to determine the primary post-natal event that results in cardiomyocyte cell-cycle arrest. We hypothesized that transition to the oxygen rich postnatal environment is the upstream signal that results in cell cycle arrest of cardiomyocytes. Here we show that reactive oxygen species (ROS), oxidative DNA damage, and D...

  11. Quantum Dots Do Not Alter the Differentiation Potential of Pancreatic Stem Cells and Are Distributed Randomly among Daughter Cells.

    Science.gov (United States)

    Danner, S; Benzin, H; Vollbrandt, T; Oder, J; Richter, A; Kruse, C

    2013-01-01

    With the increasing relevance of cell-based therapies, there is a demand for cell-labeling techniques for in vitro and in vivo studies. For the reasonable tracking of transplanted stem cells in animal models, the usage of quantum dots (QDs) for sensitive cellular imaging has major advances. QDs could be delivered to the cytoplasm of the cells providing intense and stable fluorescence. Although QDs are emerging as favourable nanoparticles for bioimaging, substantial investigations are still required to consider their application for adult stem cells. Therefore, rat pancreatic stem cells (PSCs) were labeled with different concentrations of CdSe quantum dots (Qtracker 605 nanocrystals). The QD labeled PSCs showed normal proliferation and their usual spontaneous differentiation potential in vitro. The labeling of the cell population was concentration dependent, with increasing cell load from 5 nM QDs to 20 nM QDs. With time-lapse microscopy, we observed that the transmission of the QD particles during cell divisions was random, appearing as equal or unequal transmission to daughter cells. We report here that QDs offered an efficient and nontoxic way to label pancreatic stem cells without genetic modifications. In summary, QD nanocrystals are a promising tool for stem cell labeling and facilitate tracking of transplanted cells in animal models. PMID:23997768

  12. Growth inhibitory effect of 4-phenyl butyric acid on human gastric cancer cells is associated with cell cycle arrest

    Institute of Scientific and Technical Information of China (English)

    Long-Zhu Li; Hong-Xia Deng; Wen-Zhu Lou; Xue-Yan Sun; Meng-Wan Song; Jing Tao; Bing-Xiu Xiao; Jun-Ming Guo

    2012-01-01

    AIM: To investigate the growth effects of 4-phenyl butyric acid (PBA) on human gastric carcinoma cells and their mechanisms. METHODS: Moderately-differentiated human gastric carcinoma SGC-7901 and lowly-differentiated MGC-803 cells were treated with 5, 10, 20, 40, and 60 μmol/L PBA for 1-4 d. Cell proliferation was detected using the MTT colorimetric assay. Cell cycle distributions were examined using flow cytometry. RESULTS: The proliferation of gastric carcinoma cells was inhibited by PBA in a dose- and time-dependent fashion. Flow cytometry showed that SGC-7901 cells treated with low concentrations of PBA were arrested at the G0/G1 phase, whereas cells treated with high concentrations of PBA were arrested at the G2/M phase. Although MGC-803 cells treated with low concentrations of PBA were also arrested at the G0/G1 phase, cells treated with high concentrations of PBA were arrested at the S phase. CONCLUSION: The growth inhibitory effect of PBA on gastric cancer cells is associated with alteration of the cell cycle. For moderately-differentiated gastric cancer cells, the cell cycle was arrested at the G0/G1 and G2/M phases. For lowly-differentiated gastric cancer cells, the cell cycle was arrested at the G0/G1 and S phases.

  13. TRICHOSTATIN A INHIBITS PROLIFERATION, INDUCES APOPTOSIS AND CELL CYCLE ARREST IN HELA CELLS

    Institute of Scientific and Technical Information of China (English)

    XU Zhou-min; WANG Yi-qun; MEI Qi; CHEN Jian; DU Jia; WEI Yan; XU Ying-chun

    2006-01-01

    Objective: The histone deacetylase inhibitors (HDACIS) have been shown to inhibit cancer cell proliferation, stimulate apoptosis, an induce cell cycle arrest. Our purpose was to investigate the antiproliferative effects of a HDACI, trichostatin A (TSA), against human cervical cancer cells (HeLa). Methods: HeLa cells were treated in vitro with various concentrations of TSA. The inhibitory effect of TSA on the growth of HeLa cells was measured by MTT assay. To detect the characteristic of apoptosis chromatin condensation, HeLa cells were stained with Hoechst 33258 in the presence of TSA. Induction of cell cycle arrest was studied by flow cytometry. Changes in gene expression of p53, p21Waf1 and p27Kip1 were studied by semiquantitative RT-PCR. Results: TSA inhibited cell growth in a time- and dose-dependent manner. Hoechst 33258 staining assay showed that TSA induced apoptosis. Cell cycle analysis indicated that treatment with TSA decreased the proportion of cells in S phase and increased the proportion of cells in G0/G1 and/or G2/M phases of the cell cycle. This was concomitant with overexpression of genes related to malignant phenotype, including an increase in p53, p21Waf1 and p27Kip1. Conclusion: These results suggest that TSA is effective in inhibiting growth of HeLa cells in vitro. The findings raise the possibility that TSA may prove particularly effective in treatment of cervical cancers.

  14. Salidroside induces cell-cycle arrest and apoptosis in human breast cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Xiaolan, E-mail: huxiaolan1998@yahoo.com.cn [Department of Pathology and Pathophysiology, Zhejiang University School of Medicine, Hangzhou (China); Zhang, Xianqi [The 2nd Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou (China); Qiu, Shuifeng [Department of Pathology and Pathophysiology, Zhejiang University School of Medicine, Hangzhou (China); Yu, Daihua; Lin, Shuxin [Fourth Military Medical University, Xi' an (China)

    2010-07-16

    Research highlights: {yields} Salidroside inhibits the growth of human breast cancer cells. {yields} Salidroside induces cell-cycle arrest of human breast cancer cells. {yields} Salidroside induces apoptosis of human breast cancer cell lines. -- Abstract: Recently, salidroside (p-hydroxyphenethyl-{beta}-D-glucoside) has been identified as one of the most potent compounds isolated from plants of the Rhodiola genus used widely in traditional Chinese medicine, but pharmacokinetic data on the compound are unavailable. We were the first to report the cytotoxic effects of salidroside on cancer cell lines derived from different tissues, and we found that human breast cancer MDA-MB-231 cells (estrogen receptor negative) were sensitive to the inhibitory action of low-concentration salidroside. To further investigate the cytotoxic effects of salidroside on breast cancer cells and reveal possible ER-related differences in response to salidroside, we used MDA-MB-231 cells and MCF-7 cells (estrogen receptor-positive) as models to study possible molecular mechanisms; we evaluated the effects of salidroside on cell growth characteristics, such as proliferation, cell cycle duration, and apoptosis, and on the expression of apoptosis-related molecules. Our results demonstrated for the first time that salidroside induces cell-cycle arrest and apoptosis in human breast cancer cells and may be a promising candidate for breast cancer treatment.

  15. DNA Damage, Cell Cycle Arrest, and Apoptosis Induction Caused by Lead in Human Leukemia Cells.

    Science.gov (United States)

    Yedjou, Clement G; Tchounwou, Hervey M; Tchounwou, Paul B

    2016-01-01

    In recent years, the industrial use of lead has been significantly reduced from paints and ceramic products, caulking, and pipe solder. Despite this progress, lead exposure continues to be a significant public health concern. The main goal of this research was to determine the in vitro mechanisms of lead nitrate [Pb(NO₃)₂] to induce DNA damage, apoptosis, and cell cycle arrest in human leukemia (HL-60) cells. To reach our goal, HL-60 cells were treated with different concentrations of Pb(NO₃)₂ for 24 h. Live cells and necrotic death cells were measured by the propidium idiode (PI) assay using the cellometer vision. Cell apoptosis was measured by the flow cytometry and DNA laddering. Cell cycle analysis was evaluated by the flow cytometry. The result of the PI demonstrated a significant (p rupture by Pb(NO₃)₂ compared to the control. Data generated from the comet assay indicated a concentration-dependent increase in DNA damage, showing a significant increase (p < 0.05) in comet tail-length and percentages of DNA cleavage. Data generated from the flow cytometry assessment indicated that Pb(NO₃)₂ exposure significantly (p < 0.05) increased the proportion of caspase-3 positive cells (apoptotic cells) compared to the control. The flow cytometry assessment also indicated Pb(NO₃)₂ exposure caused cell cycle arrest at the G₀/G₁ checkpoint. The result of DNA laddering assay showed presence of DNA smear in the agarose gel with little presence of DNA fragments in the treated cells compared to the control. In summary, Pb(NO₃)₂ inhibits HL-60 cells proliferation by not only inducing DNA damage and cell cycle arrest at the G₀/G₁ checkpoint but also triggering the apoptosis through caspase-3 activation and nucleosomal DNA fragmentation accompanied by secondary necrosis. We believe that our study provides a new insight into the mechanisms of Pb(NO₃)₂ exposure and its associated adverse health effects. PMID:26703663

  16. Withaferin-A induces mitotic catastrophe and growth arrest in prostate cancer cells

    OpenAIRE

    Roy, Ram V; Suman, Suman; Das, Trinath P; Luevano, Joe; Damodaran, Chendil

    2013-01-01

    Cell cycle deregulation is strongly associated with the pathogenesis of prostate cancer (CaP). Clinical trials of cell cycle regulators that target either the G0/G1 or G2/M phase to inhibit the growth of cancers including CaP are increasing. In this study, we determined the cell-cycle regulatory potential of the herbal molecule Withaferin-A (WA) on CaP cells. WA induced irreversible G2/M arrest in both CaP cell lines (PC3 and DU145) for 48 h. The G2/M arrest was accompanied by upregulation of...

  17. Systematic analysis of asymmetric partitioning of yeast proteome between mother and daughter cells reveals “aging factors” and mechanism of lifespan asymmetry

    OpenAIRE

    Yang, Jing; McCormick, Mark A.; Zheng, Jiashun; Xie, Zhengwei; Tsuchiya, Mitsuhiro; Tsuchiyama, Scott; El-Samad, Hana; Ouyang, Qi; Kaeberlein, Matt; Kennedy, Brian K.; Li, Hao

    2015-01-01

    In this work, we took a proteome-centric view to analyze the cell division and lifespan asymmetry between mother and daughter cells in budding yeast. Using a flow cytometry-based, high-throughput approach, we quantified the partitioning of the proteome and identified 74 mother-enriched and 60 daughter-enriched proteins. Functional analysis of these proteins suggests mechanisms of asymmetric partitioning at an organelle/suborganelle level. We found that mother-enriched proteins are much more l...

  18. Piperlongumine Suppresses Proliferation of Human Oral Squamous Cell Carcinoma through Cell Cycle Arrest, Apoptosis and Senescence.

    Science.gov (United States)

    Chen, San-Yuan; Liu, Geng-Hung; Chao, Wen-Ying; Shi, Chung-Sheng; Lin, Ching-Yen; Lim, Yun-Ping; Lu, Chieh-Hsiang; Lai, Peng-Yeh; Chen, Hau-Ren; Lee, Ying-Ray

    2016-01-01

    Oral squamous cell carcinoma (OSCC), an aggressive cancer originating in the oral cavity, is one of the leading causes of cancer deaths in males worldwide. This study investigated the antitumor activity and mechanisms of piperlongumine (PL), a natural compound isolated from Piper longum L., in human OSCC cells. The effects of PL on cell proliferation, the cell cycle, apoptosis, senescence and reactive oxygen species (ROS) levels in human OSCC cells were investigated. PL effectively inhibited cell growth, caused cell cycle arrest and induced apoptosis and senescence in OSCC cells. Moreover, PL-mediated anti-human OSCC behavior was inhibited by an ROS scavenger N-acetyl-l-cysteine (NAC) treatment, suggesting that regulation of ROS was involved in the mechanism of the anticancer activity of PL. These findings suggest that PL suppresses tumor growth by regulating the cell cycle and inducing apoptosis and senescence and is a potential chemotherapy agent for human OSCC cells. PMID:27120594

  19. Piperlongumine Suppresses Proliferation of Human Oral Squamous Cell Carcinoma through Cell Cycle Arrest, Apoptosis and Senescence

    Directory of Open Access Journals (Sweden)

    San-Yuan Chen

    2016-04-01

    Full Text Available Oral squamous cell carcinoma (OSCC, an aggressive cancer originating in the oral cavity, is one of the leading causes of cancer deaths in males worldwide. This study investigated the antitumor activity and mechanisms of piperlongumine (PL, a natural compound isolated from Piper longum L., in human OSCC cells. The effects of PL on cell proliferation, the cell cycle, apoptosis, senescence and reactive oxygen species (ROS levels in human OSCC cells were investigated. PL effectively inhibited cell growth, caused cell cycle arrest and induced apoptosis and senescence in OSCC cells. Moreover, PL-mediated anti-human OSCC behavior was inhibited by an ROS scavenger N-acetyl-l-cysteine (NAC treatment, suggesting that regulation of ROS was involved in the mechanism of the anticancer activity of PL. These findings suggest that PL suppresses tumor growth by regulating the cell cycle and inducing apoptosis and senescence and is a potential chemotherapy agent for human OSCC cells.

  20. IARS2 silencing induces non-small cell lung cancer cells proliferation inhibition, cell cycle arrest and promotes cell apoptosis.

    Science.gov (United States)

    Yin, J; Liu, W; Li, R; Liu, J; Zhang, Y; Tang, W; Wang, K

    2016-01-01

    The purpose of this study was to investigate the potential role of Ileucyl-tRNA synthetase (IARS2) silencing in non-small cell lung cancer (NSCLC). The silencing of IARS2 in H1299 cells and A549 cells were performed by lentivirus encoding shRNAs. The efficiency of IARS2 silencing was detected by quantitative real time PCR and western blot. The effects of IARS2 silencing on cell growth, cell apoptosis, cell cycle and cell colony formation ability were assessed by cells counting, MTT assay, flow cytometer analysis and soft agar colony formation assay, respectively. Compared with negative control group, IARS2 was significantly knockdown by transfection with lentivirus encoding shRNA of IARS2. The IARS2 silencing significantly inhibited the cells proliferation and cells colony formation ability, induced cell cycle arrest at G1/S phase and promoted cell apoptosis. IARS2 silencing induced NSCLC cells growth inhibition, cell cycle arrest and promoted cell apoptosis. These results suggest that IARS2 may be a novel target for the treatment of NSCLC. PMID:26639235

  1. DNA Damage, Cell Cycle Arrest, and Apoptosis Induction Caused by Lead in Human Leukemia Cells

    OpenAIRE

    Yedjou, Clement G.; Tchounwou, Hervey M.; Tchounwou, Paul B.

    2015-01-01

    In recent years, the industrial use of lead has been significantly reduced from paints and ceramic products, caulking, and pipe solder. Despite this progress, lead exposure continues to be a significant public health concern. The main goal of this research was to determine the in vitro mechanisms of lead nitrate [Pb(NO3)2] to induce DNA damage, apoptosis, and cell cycle arrest in human leukemia (HL-60) cells. To reach our goal, HL-60 cells were treated with different concentrations of Pb(NO3)...

  2. Bach1 Induces Endothelial Cell Apoptosis and Cell-Cycle Arrest through ROS Generation

    Science.gov (United States)

    Wang, Xinhong; Liu, Junxu; Jiang, Li; Wei, Xiangxiang; Niu, Cong; Wang, Rui; Zhang, Jianyi; Yao, Kang

    2016-01-01

    The transcription factor BTB and CNC homology 1 (Bach1) regulates genes involved in the oxidative stress response and cell-cycle progression. We have recently shown that Bach1 impairs cell proliferation and promotes apoptosis in cultured endothelial cells (ECs), but the underlying mechanisms are largely uncharacterized. Here we demonstrate that Bach1 upregulation impaired the blood flow recovery from hindlimb ischemia and this effect was accompanied both by increases in reactive oxygen species (ROS) and cleaved caspase 3 levels and by declines in the expression of cyclin D1 in the injured tissues. We found that Bach1 overexpression induced mitochondrial ROS production and caspase 3-dependent apoptosis and its depletion attenuated H2O2-induced apoptosis in cultured human microvascular endothelial cells (HMVECs). Bach1-induced apoptosis was largely abolished when the cells were cultured with N-acetyl-l-cysteine (NAC), a ROS scavenger. Exogenous expression of Bach1 inhibited the cell proliferation and the expression of cyclin D1, induced an S-phase arrest, and increased the expression of cyclin E2, which were partially blocked by NAC. Taken together, our results suggest that Bach1 suppresses cell proliferation and induces cell-cycle arrest and apoptosis by increasing mitochondrial ROS production, suggesting that Bach1 may be a promising treatment target for the treatment of vascular diseases. PMID:27057283

  3. Radioprotection and Cell Cycle Arrest of Intestinal Epithelial Cells by Darinaparsin, a Tumor Radiosensitizer

    Energy Technology Data Exchange (ETDEWEB)

    Tian, Junqiang; Doi, Hiroshi [Department of Radiation Oncology, School of Medicine, Stanford University, Stanford, California (United States); Saar, Matthias; Santos, Jennifer [Department of Urology, School of Medicine, Stanford University, Stanford, California (United States); Li, Xuejun; Peehl, Donna M. [Department of Radiation Oncology, School of Medicine, Stanford University, Stanford, California (United States); Knox, Susan J., E-mail: sknox@stanford.edu [Department of Radiation Oncology, School of Medicine, Stanford University, Stanford, California (United States)

    2013-12-01

    Purpose: It was recently reported that the organic arsenic compound darinaparsin (DPS) is a cytotoxin and radiosensitizer of tumor cells in vitro and in subcutaneous xenograft tumors. Surprisingly, it was also found that DPS protects normal intestinal crypt epithelial cells (CECs) from clonogenic death after ionizing radiation (IR). Here we tested the DPS radiosensitizing effect in a clinically relevant model of prostate cancer and explored the radioprotective effect and mechanism of DPS on CECs. Methods and Materials: The radiation modification effect of DPS was tested in a mouse model of orthotopic xenograft prostate cancer and of IR-induced acute gastrointestinal syndrome. The effect of DPS on CEC DNA damage and DNA damage responses was determined by immunohistochemistry. Results: In the mouse model of IR-induced gastrointestinal syndrome, DPS treatment before IR accelerated recovery from body weight loss and increased animal survival. DPS decreased post-IR DNA damage and cell death, suggesting that the radioprotective effect was mediated by enhanced DNA damage repair. Shortly after DPS injection, significant cell cycle arrest was observed in CECs at both G1/S and G2/M checkpoints, which was accompanied by the activation of cell cycle inhibitors p21 and growth arrest and DNA-damage-inducible protein 45 alpha (GADD45A). Further investigation revealed that DPS activated ataxia telangiectasia mutated (ATM), an important inducer of DNA damage repair and cell cycle arrest. Conclusions: DPS selectively radioprotected normal intestinal CECs and sensitized prostate cancer cells in a clinically relevant model. This effect may be, at least in part, mediated by DNA damage response activation and has the potential to significantly increase the therapeutic index of radiation therapy.

  4. Radioprotection and Cell Cycle Arrest of Intestinal Epithelial Cells by Darinaparsin, a Tumor Radiosensitizer

    International Nuclear Information System (INIS)

    Purpose: It was recently reported that the organic arsenic compound darinaparsin (DPS) is a cytotoxin and radiosensitizer of tumor cells in vitro and in subcutaneous xenograft tumors. Surprisingly, it was also found that DPS protects normal intestinal crypt epithelial cells (CECs) from clonogenic death after ionizing radiation (IR). Here we tested the DPS radiosensitizing effect in a clinically relevant model of prostate cancer and explored the radioprotective effect and mechanism of DPS on CECs. Methods and Materials: The radiation modification effect of DPS was tested in a mouse model of orthotopic xenograft prostate cancer and of IR-induced acute gastrointestinal syndrome. The effect of DPS on CEC DNA damage and DNA damage responses was determined by immunohistochemistry. Results: In the mouse model of IR-induced gastrointestinal syndrome, DPS treatment before IR accelerated recovery from body weight loss and increased animal survival. DPS decreased post-IR DNA damage and cell death, suggesting that the radioprotective effect was mediated by enhanced DNA damage repair. Shortly after DPS injection, significant cell cycle arrest was observed in CECs at both G1/S and G2/M checkpoints, which was accompanied by the activation of cell cycle inhibitors p21 and growth arrest and DNA-damage-inducible protein 45 alpha (GADD45A). Further investigation revealed that DPS activated ataxia telangiectasia mutated (ATM), an important inducer of DNA damage repair and cell cycle arrest. Conclusions: DPS selectively radioprotected normal intestinal CECs and sensitized prostate cancer cells in a clinically relevant model. This effect may be, at least in part, mediated by DNA damage response activation and has the potential to significantly increase the therapeutic index of radiation therapy

  5. Mechanisms involved in ceramide-induced cell cycle arrest in human hepatocarcinoma cells

    Institute of Scientific and Technical Information of China (English)

    Jing Wang; Xiao-Wen Lv; Jie-Ping Shi; Xiao-Song Hu

    2007-01-01

    AIM:To investigate the effect of ceramide on the cell cycle in human hepatocarcinoma Bel7402 cells.Possible molecular mechanisms were explored.METHODS:[3-(4,5)-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide(MTT)assay,plasmid transfection,reporter assay,FACS and Western blotting analyses were employed to investigate the effect and the related molecular mechanisms of C2-ceramide on the cell cycle of Bel7402 cells.RESULTS:C2-ceramide was found to inhibit the growth of Bel7402 cells by inducing cell cycle arrest.During the process,the expression of p21 protein increased,while that of cyclinD1,phospho-ERK1/2 and c-myc decreased.Furthermore,the level of CDK7 was downregulated,while the transcriptional activity of PPARγ was upregulated.Addition of GW9662,which is a PPARγ specific antagonist,could reserve the modulation action on CDK7.CONCLUSION:Our results support the hypothesis that cell cycle arrest induced by C2-ceramide may be mediated via accumulation of p21 and reduction of cyclinD1 and CDK7,at least partly,through PPARγ activation.The ERK signaling pathway was involved in this process.

  6. Tea pigments induce cell-cycle arrest and apoptosis in HepG2 cells

    Institute of Scientific and Technical Information of China (English)

    Xu-Dong Jia; Chi Han; Jun-Shi Chen

    2005-01-01

    AIM: To investigate the molecular mechanisms by which tea pigments exert preventive effects on liver carcinogenesis.METHODS: HepG2 cells were seeded at a density of 5×105/well in six-well culture dishes and incubated overnight. The cells then were treated with various concentrations of tea pigments over 3 d, harvested by trypsinization, and counted using a hemocytometer. Flow cytometric analysis was performed by a flow cytometer after propidium iodide labeling. Bcl-2 and p21WAF1 proteins were determined by Western blotting. In addition, DNA laddering assay was performed on treated and untreated cultured HepG2 cells.RESULTS: Tea pigments inhibited the growth of HepG2 cells in a dose-dependent manner. Flow-cytometric analysis showed that tea pigments arrested cell cycle progression at G1 phase. DNA laddering was used to investigate apoptotic cell death, and the result showed that 100 mg/L of tea pigments caused typical DNA laddering. Our study also showed that tea pigments induced upregulation of p21WAF1 protein and downregulation of Bcl-2 protein.CONCLUSION: Tea pigments induce cell-cycle arrest and apoptosis. Tea pigments may be used as an ideal chemopreventive agent.

  7. Soaking RNAi in Bombyx mori BmN4-SID1 cells arrests cell cycle progression.

    Science.gov (United States)

    Mon, Hiroaki; Li, Zhiqing; Kobayashi, Isao; Tomita, Shuichiro; Lee, JaeMan; Sezutsu, Hideki; Tamura, Toshiki; Kusakabe, Takahiro

    2013-01-01

    RNA interference (RNAi) is an evolutionarily conserved mechanism for sequence-specific gene silencing. Previously, the BmN4-SID1 cell expressing Caenorhabditis ele gans SID-1 was established, in which soaking RNAi could induce effective gene silencing. To establish its utility, 6 cell cycle progression related cDNAs, CDK1, MYC, MYB, RNRS, CDT1, and GEMININ, were isolated from the silkworm, Bombyx mori L. (Lepidoptera: Bombycidae), and their expressions were further silenced by soaking RNAi in the BmN4-SID1 cells. The cell cycle progression analysis using flow cytometer demonstrated that the small amount of double stranded RNA was enough to arrest cell cycle progression at the specific cell phases. These data suggest that RNAi in the BmN4-SID1 cells can be used as a powerful tool for loss-of-function analysis of B. mori genes. PMID:24773378

  8. Costunolide causes mitotic arrest and enhances radiosensitivity in human hepatocellular carcinoma cells

    Directory of Open Access Journals (Sweden)

    Chen Chih-Jen

    2011-05-01

    Full Text Available Abstract Purpose This work aimed to investigate the effect of costunolide, a sesquiterpene lactone isolated from Michelia compressa, on cell cycle distribution and radiosensitivity of human hepatocellular carcinoma (HCC cells. Methods The assessment used in this study included: cell viability assay, cell cycle analysis by DNA histogram, expression of phosphorylated histone H3 (Ser 10 by flow cytometer, mitotic index by Liu's stain and morphological observation, mitotic spindle alignment by immunofluorescence of alpha-tubulin, expression of cell cycle-related proteins by Western blotting, and radiation survival by clonogenic assay. Results Our results show that costunolide reduced the viability of HA22T/VGH cells. It caused a rapid G2/M arrest at 4 hours shown by DNA histogram. The increase in phosphorylated histone H3 (Ser 10-positive cells and mitotic index indicates costunolide-treated cells are arrested at mitosis, not G2, phase. Immunofluorescence of alpha-tubulin for spindle formation further demonstrated these cells are halted at metaphase. Costunolide up-regulated the expression of phosphorylated Chk2 (Thr 68, phosphorylated Cdc25c (Ser 216, phosphorylated Cdk1 (Tyr 15 and cyclin B1 in HA22T/VGH cells. At optimal condition causing mitotic arrest, costunolide sensitized HA22T/VGH HCC cells to ionizing radiation with sensitizer enhancement ratio up to 1.9. Conclusions Costunolide could reduce the viability and arrest cell cycling at mitosis in hepatoma cells. Logical exploration of this mitosis-arresting activity for cancer therapeutics shows costunolide enhanced the killing effect of radiotherapy against human HCC cells.

  9. Costunolide causes mitotic arrest and enhances radiosensitivity in human hepatocellular carcinoma cells

    International Nuclear Information System (INIS)

    This work aimed to investigate the effect of costunolide, a sesquiterpene lactone isolated from Michelia compressa, on cell cycle distribution and radiosensitivity of human hepatocellular carcinoma (HCC) cells. The assessment used in this study included: cell viability assay, cell cycle analysis by DNA histogram, expression of phosphorylated histone H3 (Ser 10) by flow cytometer, mitotic index by Liu's stain and morphological observation, mitotic spindle alignment by immunofluorescence of alpha-tubulin, expression of cell cycle-related proteins by Western blotting, and radiation survival by clonogenic assay. Our results show that costunolide reduced the viability of HA22T/VGH cells. It caused a rapid G2/M arrest at 4 hours shown by DNA histogram. The increase in phosphorylated histone H3 (Ser 10)-positive cells and mitotic index indicates costunolide-treated cells are arrested at mitosis, not G2, phase. Immunofluorescence of alpha-tubulin for spindle formation further demonstrated these cells are halted at metaphase. Costunolide up-regulated the expression of phosphorylated Chk2 (Thr 68), phosphorylated Cdc25c (Ser 216), phosphorylated Cdk1 (Tyr 15) and cyclin B1 in HA22T/VGH cells. At optimal condition causing mitotic arrest, costunolide sensitized HA22T/VGH HCC cells to ionizing radiation with sensitizer enhancement ratio up to 1.9. Costunolide could reduce the viability and arrest cell cycling at mitosis in hepatoma cells. Logical exploration of this mitosis-arresting activity for cancer therapeutics shows costunolide enhanced the killing effect of radiotherapy against human HCC cells

  10. Reversible cryo-arrest for imaging molecules in living cells at high spatial resolution.

    Science.gov (United States)

    Masip, Martin E; Huebinger, Jan; Christmann, Jens; Sabet, Ola; Wehner, Frank; Konitsiotis, Antonios; Fuhr, Günther R; Bastiaens, Philippe I H

    2016-08-01

    The dynamics of molecules in living cells hampers precise imaging of molecular patterns by functional and super-resolution microscopy. We developed a method that circumvents lethal chemical fixation and allows on-stage cryo-arrest for consecutive imaging of molecular patterns within the same living, but arrested, cells. The reversibility of consecutive cryo-arrests was demonstrated by the high survival rate of different cell lines and by intact growth factor signaling that was not perturbed by stress response. Reversible cryo-arrest was applied to study the evolution of ligand-induced receptor tyrosine kinase activation at different scales. The nanoscale clustering of epidermal growth factor receptor (EGFR) in the plasma membrane was assessed by single-molecule localization microscopy, and endosomal microscale activity patterns of ephrin receptor A2 (EphA2) were assessed by fluorescence lifetime imaging microscopy. Reversible cryo-arrest allows the precise determination of molecular patterns while conserving the dynamic capabilities of living cells. PMID:27400419

  11. Osthole inhibits proliferation of human breast cancer cells by inducing cell cycle arrest and apoptosis

    Institute of Scientific and Technical Information of China (English)

    Lintao Wang; Yanyan Peng; Kaikai Shi; Haixiao Wang; Jianlei Lu; Yanli Li; Changyan Ma

    2015-01-01

    Recent studies have revealed that osthole,an active constituent isolated from the fruit of Cnidium monnieri (L.) Cusson,a traditional Chinese medicine,possesses anticancer activity.However,its effect on breast cancer cells so far has not been elucidated clearly.In the present study,we evaluated the effects of osthole on the proliferation,cell cycle and apoptosis of human breast cancer cells MDA-MB 435.We demonstrated that osthole is effective in inhibiting the proliferation of MDA-MB 435 cells,The mitochondrion-mediated apoptotic pathway was involved in apoptosis induced by osthole,as indicated by activation of caspase-9 and caspase-3 followed by PARP degradation.The mechanism underlying its effect on the induction of G1 phase arrest was due to the up-regulation of p53 and p21 and down-regulation of Cdk2 and cyclin D1 expression.Were observed taken together,these findings suggest that the anticancer efficacy of osthole is mediated via induction of cell cycle arrest and apoptosis in human breast cancer cells and osthole may be a potential chemotherapeutic agent against human breast cancer.

  12. DNA Damage, Cell Cycle Arrest, and Apoptosis Induction Caused by Lead in Human Leukemia Cells

    Directory of Open Access Journals (Sweden)

    Clement G. Yedjou

    2015-12-01

    Full Text Available In recent years, the industrial use of lead has been significantly reduced from paints and ceramic products, caulking, and pipe solder. Despite this progress, lead exposure continues to be a significant public health concern. The main goal of this research was to determine the in vitro mechanisms of lead nitrate [Pb(NO32] to induce DNA damage, apoptosis, and cell cycle arrest in human leukemia (HL-60 cells. To reach our goal, HL-60 cells were treated with different concentrations of Pb(NO32 for 24 h. Live cells and necrotic death cells were measured by the propidium idiode (PI assay using the cellometer vision. Cell apoptosis was measured by the flow cytometry and DNA laddering. Cell cycle analysis was evaluated by the flow cytometry. The result of the PI demonstrated a significant (p < 0.05 increase of necrotic cell death in Pb(NO32-treated cells, indicative of membrane rupture by Pb(NO32 compared to the control. Data generated from the comet assay indicated a concentration-dependent increase in DNA damage, showing a significant increase (p < 0.05 in comet tail-length and percentages of DNA cleavage. Data generated from the flow cytometry assessment indicated that Pb(NO32 exposure significantly (p < 0.05 increased the proportion of caspase-3 positive cells (apoptotic cells compared to the control. The flow cytometry assessment also indicated Pb(NO32 exposure caused cell cycle arrest at the G0/G1 checkpoint. The result of DNA laddering assay showed presence of DNA smear in the agarose gel with little presence of DNA fragments in the treated cells compared to the control. In summary, Pb(NO32 inhibits HL-60 cells proliferation by not only inducing DNA damage and cell cycle arrest at the G0/G1 checkpoint but also triggering the apoptosis through caspase-3 activation and nucleosomal DNA fragmentation accompanied by secondary necrosis. We believe that our study provides a new insight into the mechanisms of Pb(NO32 exposure and its associated adverse

  13. Berberine induces p53-dependent cell cycle arrest and apoptosis of human osteosarcoma cells by inflicting DNA damage

    Energy Technology Data Exchange (ETDEWEB)

    Liu Zhaojian; Liu Qiao; Xu Bing; Wu Jingjing [Key Laboratory of Experimental Teratology of Ministry of Education and Institute of Molecular Medicine and Genetics, Shandong University School of Medicine, Jinan, Shandong 250012 (China); Guo Chun; Zhu Faliang [Institute of Immunology, Shandong University School of Medicine, Jinan, Shandong 250012 (China); Yang Qiaozi [Department of Genetics, Rutgers University, Piscataway, NJ 08854 (United States); Gao Guimin [Key Laboratory of Experimental Teratology of Ministry of Education and Institute of Molecular Medicine and Genetics, Shandong University School of Medicine, Jinan, Shandong 250012 (China); Gong Yaoqin [Key Laboratory of Experimental Teratology of Ministry of Education and Institute of Molecular Medicine and Genetics, Shandong University School of Medicine, Jinan, Shandong 250012 (China)], E-mail: yxg8@sdu.edu.cn; Shao Changshun [Key Laboratory of Experimental Teratology of Ministry of Education and Institute of Molecular Medicine and Genetics, Shandong University School of Medicine, Jinan, Shandong 250012 (China); Department of Genetics, Rutgers University, Piscataway, NJ 08854 (United States)], E-mail: shao@biology.rutgers.edu

    2009-03-09

    Alkaloid berberine is widely used for the treatment of diarrhea and other diseases. Many laboratory studies showed that it exhibits anti-proliferative activity against a wide spectrum of cancer cells in culture. In this report we studied the mechanisms underlying the inhibitory effects of berberine on human osteosarcoma cells and on normal osteoblasts. The inhibition was largely attributed to cell cycle arrest at G1 and G2/M, and to a less extent, to apoptosis. The G1 arrest was dependent on p53, as G1 arrest was abolished in p53-deficient osteosarcoma cells. The induction of G1 arrest and apoptosis was accompanied by a p53-dependent up-regulation of p21 and pro-apoptotic genes. However, the G2/M arrest could be induced by berberine regardless of the status of p53. Interestingly, DNA double-strand breaks, as measured by the phosphorylation of H2AX, were remarkably accumulated in berberine-treated cells in a dose-dependent manner. Thus, one major mechanism by which berberine exerts its growth-inhibitory effect is to inflict genomic lesions on cells, which in turn trigger the activation of p53 and the p53-dependent cellular responses including cell cycle arrest and apoptosis.

  14. Berberine induces cell cycle arrest and apoptosis in human gastric carcinoma SNU-5 cell line

    Institute of Scientific and Technical Information of China (English)

    Jing-Pin Lin; Jai-Sing Yang; Jau-Hong Lee; Wen-Tsong Hsieh; Jing-Gung Chung

    2006-01-01

    AIM: To investigate the relationship between the inhibited growth (cytotoxic activity) of berberine and apoptotic pathway with its molecular mechanism of action.METHODS: The in vitro cytotoxic techniques were complemented by cell cycle analysis and determination of sub-G1 for apoptosis in human gastric carcinoma SNU-5 cells. Percentage of viable cells, cell cycle, and sub-G1 group (apoptosis) were examined and determined by the flow cytometric methods. The associated proteins for cell cycle arrest and apoptosis were examined by Western blotting.RESULTS: For SNU-5 cell line, the IC (50) was found to be 48 μmol/L of berberine. In SNU-5 cells treated with 25-200 μmol/L berberine, G2/M cell cycle arrest was observed which was associated with a marked increment of the expression of p53, Wee1 and CDk1 proteins and decreased cyclin B. A concentration-dependent decrease of cells in G0/G1 phase and an increase in G2/M phase were detected. In addition, apoptosis detected as sub-G0 cell population in cell cycle measurement was proved in 25-200 μmol/L berberine-treated cells by monitoring the apoptotic pathway. Apoptosis was identified by sub-G0 cell population, and upregulation of Bax, downregulation of Bcl-2, release of Ca2+, decreased the mitochondrial membrane potential and then led to the release of mitochondrial cytochrome C into the cytoplasm and caused the activation of caspase-3, and finally led to the occurrence of apoptosis.CONCLUSION: Berberine induces p53 expression and leads to the decrease of the mitochondrial membrane potential, Cytochrome C release and activation of caspase-3 for the induction of apoptosis.

  15. Role of DNA methylation in cell cycle arrest induced by Cr (VI in two cell lines.

    Directory of Open Access Journals (Sweden)

    Jianlin Lou

    Full Text Available Hexavalent chromium [Cr(IV], a well-known industrial waste product and an environmental pollutant, is recognized as a human carcinogen. But its mechanisms of carcinogenicity remain unclear, and recent studies suggest that DNA methylation may play an important role in the carcinogenesis of Cr(IV. The aim of our study was to investigate the effects of Cr(IV on cell cycle progress, global DNA methylation, and DNA methylation of p16 gene. A human B lymphoblastoid cell line and a human lung cell line A549 were exposed to 5-15 µM potassium dichromate or 1.25-5 µg/cm² lead chromate for 2-24 hours. Cell cycle was arrested at G₁ phase by both compounds in 24 hours exposure group, but global hypomethylation occurred earlier than cell cycle arrest, and the hypomethylation status maintained for more than 20 hours. The mRNA expression of p16 was significantly up-regulated by Cr(IV, especially by potassium dichromate, and the mRNA expression of cyclin-dependent kinases (CDK4 and CDK6 was significantly down-regulated. But protein expression analysis showed very little change of p16 gene. Both qualitative and quantitative results showed that DNA methylation status of p16 remained unchanged. Collectively, our data suggested that global hypomethylation was possibly responsible for Cr(IV-induced G₁ phase arrest, but DNA methylation might not be related to up-regulation of p16 gene by Cr(IV.

  16. Total triterpenoids from Ganoderma Lucidum suppresses prostate cancer cell growth by inducing growth arrest and apoptosis.

    Science.gov (United States)

    Wang, Tao; Xie, Zi-ping; Huang, Zhan-sen; Li, Hao; Wei, An-yang; Di, Jin-ming; Xiao, Heng-jun; Zhang, Zhi-gang; Cai, Liu-hong; Tao, Xin; Qi, Tao; Chen, Di-ling; Chen, Jun

    2015-10-01

    In this study, one immortalized human normal prostatic epithelial cell line (BPH) and four human prostate cancer cell lines (LNCaP, 22Rv1, PC-3, and DU-145) were treated with Ganoderma Lucidum triterpenoids (GLT) at different doses and for different time periods. Cell viability, apoptosis, and cell cycle were analyzed using flow cytometry and chemical assays. Gene expression and binding to DNA were assessed using real-time PCR and Western blotting. It was found that GLT dose-dependently inhibited prostate cancer cell growth through induction of apoptosis and cell cycle arrest at G1 phase. GLT-induced apoptosis was due to activation of Caspases-9 and -3 and turning on the downstream apoptotic events. GLT-induced cell cycle arrest (mainly G1 arrest) was due to up-regulation of p21 expression at the early time and down-regulation of cyclin-dependent kinase 4 (CDK4) and E2F1 expression at the late time. These findings demonstrate that GLT suppresses prostate cancer cell growth by inducing growth arrest and apoptosis, which might suggest that GLT or Ganoderma Lucidum could be used as a potential therapeutic drug for prostate cancer. PMID:26489631

  17. Cell cycle arrest by a gradient of Dpp signaling during Drosophila eye development

    Directory of Open Access Journals (Sweden)

    Bhattacharya Abhishek

    2010-03-01

    Full Text Available Abstract Background The secreted morphogen Dpp plays important roles in spatial regulation of gene expression and cell cycle progression in the developing Drosophila eye. Dpp signaling is required for timely cell cycle arrest ahead of the morphogenetic furrow as a prelude to differentiation, and is also important for eye disc growth. The dpp gene is expressed at multiple locations in the eye imaginal disc, including the morphogenetic furrow that sweeps across the eye disc as differentiation initiates. Results Studies of Brinker and Dad expression, and of Mad phosphorylation, establish that there is a gradient of Dpp signaling in the eye imaginal disc anterior to the morphogenetic furrow, predominantly in the anterior-posterior axis, and also Dpp signaling at the margins of the disc epithelium and in the dorsal peripodial membrane. Almost all signaling activity seems to spread through the plane of the epithelia, although peripodial epithelium cells can also respond to underlying disc cells. There is a graded requirement for Dpp signaling components for G1 arrest in the eye disc, with more stringent requirements further anteriorly where signaling is lower. The signaling level defines the cell cycle response, because elevated signaling through expression of an activated Thickveins receptor molecule arrested cells at more anterior locations. Very anterior regions of the eye disc were not arrested in response to activated receptor, however, and evidence is presented that expression of the Homothorax protein may contribute to this protection. By contrast to activated Thickveins, ectopic expression of processed Dpp leads to very high levels of Mad phosphorylation which appear to have non-physiological consequences. Conclusions G1 arrest occurs at a threshold level of Dpp signaling within a morphogen gradient in the anterior eye. G1 arrest is specific for one competent domain in the eye disc, allowing Dpp signaling to promote growth at earlier

  18. Oridonin induces apoptosis and cell cycle arrest of gallbladder cancer cells via the mitochondrial pathway

    International Nuclear Information System (INIS)

    Gallbladder cancer is the most frequent malignancy of the bile duct with high aggressive and extremely poor prognosis. The main objective of the paper was to investigate the inhibitory effects of oridonin, a diterpenoid isolated from Rabdosia rubescens, on gallbladder cancer both in vitro and in vivo and to explore the mechanisms underlying oridonin-induced apoptosis and cell cycle arrest. The anti-tumor activity of oridonin on SGC996 and NOZ cells was assessed by the MTT and colony forming assays. Cell cycle changes were detected by flow cytometric analysis. Apoptosis was detected by annexin V/PI double-staining and Hoechst 33342 staining assays. Loss of mitochondrial membrane potential was observed by Rhodamine 123 staining. The in vivo efficacy of oridonin was evaluated using a NOZ xenograft model in athymic nude mice. The expression of cell cycle- and apoptosis-related proteins in vitro and in vivo was analyzed by western blot analysis. Activation of caspases (caspase-3, -8 and -9) was measured by caspases activity assay. Oridonin induced potent growth inhibition, S-phase arrest, apoptosis, and colony-forming inhibition in SGC996 and NOZ cells in a dose-dependent manner. Intraperitoneal injection of oridonin (5, 10, or 15 mg/kg) for 3 weeks significantly inhibited the growth of NOZ xenografts in athymic nude mice. We demonstrated that oridonin regulated cell cycle-related proteins in response to S-phase arrest by western blot analysis. In contrast, we observed inhibition of NF-κB nuclear translocation and an increase Bax/Bcl-2 ratio accompanied by activated caspase-3, caspase-9 and PARP-1 cleavage after treatment with oridonin, which indicate that the mitochondrial pathway is involved in oridonin-mediated apoptosis. Oridonin possesses potent anti-gallbladder cancer activities that correlate with regulation of the mitochondrial pathway, which is critical for apoptosis and S-phase arrest. Therefore, oridonin has potential as a novel anti-tumor therapy for the

  19. Carrageenan Induces Cell Cycle Arrest in Human Intestinal Epithelial Cells in Vitro1–3

    Science.gov (United States)

    Bhattacharyya, Sumit; Borthakur, Alip; Dudeja, Pradeep K.; Tobacman, Joanne K.

    2016-01-01

    Multiple studies in animal models have shown that the commonly used food additive carrageenan (CGN) induces inflammation and intestinal neoplasia. We performed the first studies to determine the effects of CGN exposure on human intestinal epithelial cells (IEC) in tissue culture and tested the effect of very low concentrations (1–10 mg/L) of undegraded, high-molecular weight CGN. These concentrations of CGN are less than the anticipated exposure of the human colon to CGN from the average Western diet. In the human colonic epithelial cell line NCM460 and in primary human colonic epithelial cells that were exposed to CGN for 1–8 d, we found increased cell death, reduced cell proliferation, and cell cycle arrest compared with unexposed control cells. After 6–8 d of CGN exposure, the percentage of cells reentering G0–G1 significantly decreased and the percentages of cells in S and G2-M phases significantly increased. Increases in activated p53, p21, and p15 followed CGN exposure, consistent with CGN-induced cell cycle arrest. Additional data, including DNA ladder, poly ADP ribose polymerase Western blot, nuclear DNA staining, and activities of caspases 3 and 7, indicated no evidence of increased apoptosis following CGN exposure and were consistent with CGN-induced necrotic cell death. These data document for the first time, to our knowledge, marked adverse effects of low concentrations of CGN on survival of normal human IEC and suggest that CGN exposure may have a role in development of human intestinal pathology. PMID:18287351

  20. Divergence to apoptosis from ROS induced cell cycle arrest: Effect of cadmium

    International Nuclear Information System (INIS)

    Recently, the role of cadmium (Cd) in immunosupression has gained importance. Nevertheless, the signaling pathways underlying cadmium-induced immune cell death remains largely unclear. In accordance to our previous in vivo report, and to evaluate the further details of the mechanism, we have investigated the effects of cadmium (CdCl2, H2O) on cell cycle regulation and apoptosis in splenocytes in vitro. Our results have revealed that reactive oxygen species (ROS) and p21 are involved in cell cycle arrest in a p53 independent manner but late hour apoptotic response was accompanied by the p53 up-regulation, loss of mitochondrial transmembrane potential (MTP), down-regulation of Bcl-xl, activation of caspase-3 and release of cytochrome c (Cyt c). However, pifithrin alfa (PFT-α), an inhibitor of p53, fails to rescue the cells from the cadmium-induced cell cycle arrest but prevents Bcl-xl down-regulation and loss of Δψm, which indicates that there is an involvement of p53 in apoptosis. In contrast, treatment with N-acetyl cysteine (NAC) can prevent cell cycle arrest and p21 up-regulation at early hours. Although it is clear that, NAC has no effect on apoptosis, p53 expression and MPT changes at late stage events. Taken together, we have demonstrated that cadmium promotes ROS generation, which potently initiates the cell cycle arrest at early hours and finally induces p53-dependent apoptosis at later part of the event.

  1. Cell cycle arrest induced by MPPa-PDT in MDA-MB-231 cells

    Science.gov (United States)

    Liang, Liming; Bi, Wenxiang; Tian, Yuanyuan

    2016-05-01

    Photodynamic therapy (PDT) is a medical treatment using a photosensitizing agent and light source to treat cancers. Pyropheophorbidea methyl ester (MPPa), a derivative of chlorophyll, is a novel potent photosensitizer. To learn more about this photosensitizer, we examined the cell cycle arrest in MDA-MB-231. Cell cycle and apoptosis were measured by flow cytometer. Checkpoints of the cell cycle were measured by western blot. In this study, we found that the expression of Cyclin D1 was obviously decreased, while the expression of Chk2 and P21 was increased after PDT treatment. This study showed that MPPa-PDT affected the checkpoints of the cell cycle and led the cells to apoptosis.

  2. DNA Damage and Cell Cycle Arrest Induced by Protoporphyrin IX in Sarcoma 180 Cells

    Directory of Open Access Journals (Sweden)

    Qing Li

    2013-09-01

    Full Text Available Background: Porphyrin derivatives have been widely used in photodynamic therapy as effective sensitizers. Protoporphyrin IX (PpIX, a well-known hematoporphyrin derivative component, shows great potential to enhance light induced tumor cell damage. However, PpIX alone could also exert anti-tumor effects. The mechanisms underlying those direct effects are incompletely understood. This study thus investigated the putative mechanisms underlying the anti-tumor effects of PpIX on sarcoma 180 (S180 cells. Methods: S180 cells were treated with different concentrations of PpIX. Following the treatment, cell viability was evaluated by the 3-(4, 5- dimethylthiazol-2-yl-2, 5-diphenyltetrazoliumbromide (MTT assay; Disruption of mitochondrial membrane potential was measured by flow cytometry; The trans-location of apoptosis inducer factor (AIF from mitochondria to nucleus was visualized by confocal laser scanning microscopy; DNA damage was detected by single cell gel electrophoresis; Cell cycle distribution was analyzed by DNA content with flow cytometry; Cell cycle associated proteins were detected by western blotting. Results: PpIX (≥ 1 µg/ml significantly inhibited proliferation and reduced viability of S180 cells in a dose-dependent manner. PpIX rapidly and significantly triggered mitochondrial membrane depolarization, AIF (apoptosis inducer factor translocation from mitochondria to nucleus and DNA damage, effects partially relieved by the specific inhibitor of MPTP (mitochondrial permeability transition pore. Furthermore, S phase arrest and upregulation of the related proteins of P53 and P21 were observed following 12 and 24 h PpIX exposure. Conclusion: PpIX could inhibit tumor cell proliferation by induction of DNA damage and cell cycle arrest in the S phase.

  3. Piperine causes G1 phase cell cycle arrest and apoptosis in melanoma cells through checkpoint kinase-1 activation.

    Directory of Open Access Journals (Sweden)

    Neel M Fofaria

    Full Text Available In this study, we determined the cytotoxic effects of piperine, a major constituent of black and long pepper in melanoma cells. Piperine treatment inhibited the growth of SK MEL 28 and B16 F0 cells in a dose and time-dependent manner. The growth inhibitory effects of piperine were mediated by cell cycle arrest of both the cell lines in G1 phase. The G1 arrest by piperine correlated with the down-regulation of cyclin D1 and induction of p21. Furthermore, this growth arrest by piperine treatment was associated with DNA damage as indicated by phosphorylation of H2AX at Ser139, activation of ataxia telangiectasia and rad3-related protein (ATR and checkpoint kinase 1 (Chk1. Pretreatment with AZD 7762, a Chk1 inhibitor not only abrogated the activation of Chk1 but also piperine mediated G1 arrest. Similarly, transfection of cells with Chk1 siRNA completely protected the cells from G1 arrest induced by piperine. Piperine treatment caused down-regulation of E2F1 and phosphorylation of retinoblastoma protein (Rb. Apoptosis induced by piperine was associated with down-regulation of XIAP, Bid (full length and cleavage of Caspase-3 and PARP. Furthermore, our results showed that piperine treatment generated ROS in melanoma cells. Blocking ROS by tiron protected the cells from piperine mediated cell cycle arrest and apoptosis. These results suggest that piperine mediated ROS played a critical role in inducing DNA damage and activation of Chk1 leading to G1 cell cycle arrest and apoptosis.

  4. Dux4 induces cell cycle arrest at G1 phase through upregulation of p21 expression

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Hongliang; Wang, Zhaoxia; Jin, Suqin; Hao, Hongjun [Department of Neurology, Peking University First Hospital, Beijing 100034 (China); Zheng, Lemin [The Institute of Cardiovascular Sciences, Peking University Health Science Center, Key Laboratory of Molecular Cardiovascular Sciences of Education Ministry, Key Laboratory of Cardiovascular Molecular Biology and Regulatory Peptides of Health Ministry, Beijing 100191 (China); Zhou, Boda [The Department of Cardiology, Peking University Third Hospital, Beijing 100191 (China); Zhang, Wei; Lv, He [Department of Neurology, Peking University First Hospital, Beijing 100034 (China); Yuan, Yun, E-mail: yuanyun2002@sohu.com [Department of Neurology, Peking University First Hospital, Beijing 100034 (China)

    2014-03-28

    Highlights: • Dux4 induced TE671 cell proliferation defect and G1 phase arrest. • Dux4 upregulated p21 expression without activating p53. • Silencing p21 rescued Dux4 mediated proliferation defect and cell cycle arrest. • Sp1 binding site was required for Dux4-induced p21 promoter activation. - Abstract: It has been implicated that Dux4 plays crucial roles in development of facioscapulohumeral dystrophy. But the underlying myopathic mechanisms and related down-stream events of this retrogene were far from clear. Here, we reported that overexpression of Dux4 in a cell model TE671 reduced cell proliferation rate, and increased G1 phase accumulation. We also determined the impact of Dux4 on p53/p21 signal pathway, which controls the checkpoint in cell cycle progression. Overexpression of Dux4 increased p21 mRNA and protein level, while expression of p53, phospho-p53 remained unchanged. Silencing p21 rescued Dux4 mediated proliferation defect and cell cycle arrest. Furthermore, we demonstrated that enhanced Dux4 expression increased p21 promoter activity and elevated expression of Sp1 transcription factor. Mutation of Sp1 binding site decreased dux4 induced p21 promoter activation. Chromatin immunoprecipitation (ChIP) assays confirmed the Dux4-induced binding of Sp1 to p21 promoter in vivo. These results suggest that Dux4 might induce proliferation inhibition and G1 phase arrest through upregulation of p21.

  5. Effects of allitridi on cell cycle arrest of human gastric cancer cells

    Institute of Scientific and Technical Information of China (English)

    Min-Wen Ha; Rui Ma; Li-Ping Shun; Yue-Hua Gong; Yuan Yuan

    2005-01-01

    AIM: To determine the effect of allitridi on cell cycle of human gastric cancer (HGC) cell lines MGC803 and SGC7901 and its possible mechanism.METHODS: Trypan blue dye exclusion was used to evaluate the proliferation, inhibition of cells and damages of these cells were detected with electron microscope.Flow cytometry and cell mitotic index were used to analyze the change of cell cycle, immunohistochemistry, and RT-PCR was used to examine expression of the p21WAF1 gene.RESULTS: MGC803 cell growth was inhibited by allitridi with 24 h IC50 being 6.4 μg/mL. SGC7901 cell growth was also inhibited by allitridi with 24 h IC50 being 7.3 μg/mL.After being treated with allitridi at the concentration of 12 μg/mL for 24 h, cells were found to have direct cytotoxic effects, including broken cellular membrane, swollen and vesiculated mitochondria and rough endoplasmic reticula,and mass lipid droplet. When cells were treated with allitridi at the concentration of 3, 6, and 9 μg/mL for 24 h, the percentage of G0/G1 phase cells was decreased and that of G2/M phase cells was significantly increased (P = 0.002)compared with those in the group. When cells were treated with allitridi at the concentration of 6 μg/mL, cell mitotic index was much higher (P = 0.003) than that of control group, indicating that allitridi could cause gastric cancer cell arrest in M phase. Besides, the expression levels of p21WAF1 gene of MGC803 cells and p21WAF1 gene of SGC7901 cells were remarkably upregulated after treatment.CONCLUSION: Allitridi can cause gastric cancer cell arrest in M phase, and this may be one of the mechanisms for inhibiting cell proliferation. Effect of allitridi on cells in M phas e may be associated with the upregulation of p21WAF1 genes. This study provides experimental data for clinical use of allitridi in the treatment of gastric carcinoma.

  6. Prolyl oligopeptidase inhibition-induced growth arrest of human gastric cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, Kanayo [Laboratory of Cell Biology, Osaka University of Pharmaceutical Sciences, 4-20-1 Nasahara, Takatsuki, Osaka 569-1094 (Japan); Sakaguchi, Minoru, E-mail: sakaguti@gly.oups.ac.jp [Laboratory of Cell Biology, Osaka University of Pharmaceutical Sciences, 4-20-1 Nasahara, Takatsuki, Osaka 569-1094 (Japan); Tanaka, Satoshi [Laboratory of Cell Biology, Osaka University of Pharmaceutical Sciences, 4-20-1 Nasahara, Takatsuki, Osaka 569-1094 (Japan); Yoshimoto, Tadashi [Department of Life Science, Setsunan University, 17-8 Ikeda-Nakamachi, Neyagawa, Osaka 572-8508 (Japan); Takaoka, Masanori [Laboratory of Cell Biology, Osaka University of Pharmaceutical Sciences, 4-20-1 Nasahara, Takatsuki, Osaka 569-1094 (Japan)

    2014-01-03

    Highlights: •We examined the effects of prolyl oligopeptidase (POP) inhibition on p53 null gastric cancer cell growth. •POP inhibition-induced cell growth suppression was associated with an increase in a quiescent G{sub 0} state. •POP might regulate the exit from and/or reentry into the cell cycle. -- Abstract: Prolyl oligopeptidase (POP) is a serine endopeptidase that hydrolyzes post-proline peptide bonds in peptides that are <30 amino acids in length. We recently reported that POP inhibition suppressed the growth of human neuroblastoma cells. The growth suppression was associated with pronounced G{sub 0}/G{sub 1} cell cycle arrest and increased levels of the CDK inhibitor p27{sup kip1} and the tumor suppressor p53. In this study, we investigated the mechanism of POP inhibition-induced cell growth arrest using a human gastric cancer cell line, KATO III cells, which had a p53 gene deletion. POP specific inhibitors, 3-((4-[2-(E)-styrylphenoxy]butanoyl)-L-4-hydroxyprolyl)-thiazolidine (SUAM-14746) and benzyloxycarbonyl-thioprolyl-thioprolinal, or RNAi-mediated POP knockdown inhibited the growth of KATO III cells irrespective of their p53 status. SUAM-14746-induced growth inhibition was associated with G{sub 0}/G{sub 1} cell cycle phase arrest and increased levels of p27{sup kip1} in the nuclei and the pRb2/p130 protein expression. Moreover, SUAM-14746-mediated cell cycle arrest of KATO III cells was associated with an increase in the quiescent G{sub 0} state, defined by low level staining for the proliferation marker, Ki-67. These results indicate that POP may be a positive regulator of cell cycle progression by regulating the exit from and/or reentry into the cell cycle by KATO III cells.

  7. Control of Neural Daughter Cell Proliferation by Multi-level Notch/Su(H)/E(spl)-HLH Signaling.

    Science.gov (United States)

    Bivik, Caroline; MacDonald, Ryan B; Gunnar, Erika; Mazouni, Khalil; Schweisguth, Francois; Thor, Stefan

    2016-04-01

    The Notch pathway controls proliferation during development and in adulthood, and is frequently affected in many disorders. However, the genetic sensitivity and multi-layered transcriptional properties of the Notch pathway has made its molecular decoding challenging. Here, we address the complexity of Notch signaling with respect to proliferation, using the developing Drosophila CNS as model. We find that a Notch/Su(H)/E(spl)-HLH cascade specifically controls daughter, but not progenitor proliferation. Additionally, we find that different E(spl)-HLH genes are required in different neuroblast lineages. The Notch/Su(H)/E(spl)-HLH cascade alters daughter proliferation by regulating four key cell cycle factors: Cyclin E, String/Cdc25, E2f and Dacapo (mammalian p21CIP1/p27KIP1/p57Kip2). ChIP and DamID analysis of Su(H) and E(spl)-HLH indicates direct transcriptional regulation of the cell cycle genes, and of the Notch pathway itself. These results point to a multi-level signaling model and may help shed light on the dichotomous proliferative role of Notch signaling in many other systems. PMID:27070787

  8. Cell fate after mitotic arrest in different tumor cells is determined by the balance between slippage and apoptotic threshold

    Energy Technology Data Exchange (ETDEWEB)

    Galán-Malo, Patricia; Vela, Laura; Gonzalo, Oscar; Calvo-Sanjuán, Rubén; Gracia-Fleta, Lucía; Naval, Javier; Marzo, Isabel, E-mail: imarzo@unizar.es

    2012-02-01

    Microtubule poisons and other anti-mitotic drugs induce tumor death but the molecular events linking mitotic arrest to cell death are still not fully understood. We have analyzed cell fate after mitotic arrest produced by the microtubule-destabilizing drug vincristine in a panel of human tumor cell lines showing different response to vincristine. In Jurkat, RPMI 8226 and HeLa cells, apoptosis was triggered shortly after vincristine-induced mitotic arrest. However, A549 cells, which express a great amount of Bcl-x{sub L} and undetectable amounts of Bak, underwent mitotic slippage prior to cell death. However, when Bcl-x{sub L} gene was silenced in A549 cells, vincristine induced apoptosis during mitotic arrest. Another different behavior was found in MiaPaca2 cells, where vincristine caused death by mitotic catastrophe that switched to apoptosis when cyclin B1 degradation was prevented by proteasome inhibition. Overexpression of Bcl-x{sub L} or silencing Bax and Bak expression delayed the onset of apoptosis in Jurkat and RPMI 8226 cells, enabling mitotic slippage and endoreduplication. In HeLa cells, overexpression of Bcl-x{sub L} switched cell death from apoptosis to mitotic catastrophe. Mcl-1 offered limited protection to vincristine-induced cell death and Mcl-1 degradation was not essential for vincristine-induced death. All these results, taken together, indicate that the Bcl-x{sub L}/Bak ratio and the ability to degrade cyclin B1 determine cell fate after mitotic arrest in the different tumor cell types. Highlights: ► Vincristine induces cell death by apoptosis or mitotic catastrophe. ► Apoptosis-proficient cells die by apoptosis during mitosis upon vincristine treatment. ► p53wt apoptosis-deficient cells undergo apoptosis from a G1-like tetraploid state. ► p53mt apoptosis-deficient cells can survive and divide giving rise to 8N cells.

  9. Changes of the cell cycle regulators and cell cycle arrest in cervical cancer cells after cisplatin therapy

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Objective To investigate the changes of the cell cycle regulators ATM,Chk2 and p53 and cell cycle arrest in HeLa cells after cisplatin therapy. Methods The proliferation-inhibiting rates of HeLa cells induced by cisplatin of different concentrations were measured by MTT assays. The mRNA and protein expressions of ATM,Chk2 and p53 of HeLa cells with and without cisplatin were detected by RT-PCR and Western blot,respectively. The cell cycle analysis was conducted by flow cytometric analysis. Results Cisplatin...

  10. Airway Delivery of Mesenchymal Stem Cells Prevents Arrested Alveolar Growth in Neonatal Lung Injury in Rats

    OpenAIRE

    van Haaften, Timothy; Byrne, Roisin; Bonnet, Sebastien; Rochefort, Gael Y.; Akabutu, John; Bouchentouf, Manaf; Rey-Parra, Gloria J.; Galipeau, Jacques; Haromy, Alois; Eaton, Farah; Chen, Ming; Hashimoto, Kyoko; Abley, Doris; Korbutt, Greg; Archer, Stephen L.

    2009-01-01

    Rationale: Bronchopulmonary dysplasia (BPD) and emphysema are characterized by arrested alveolar development or loss of alveoli; both are significant global health problems and currently lack effective therapy. Bone marrow–derived mesenchymal stem cells (BMSCs) prevent adult lung injury, but their therapeutic potential in neonatal lung disease is unknown.

  11. The transcriptional network that controls growth arrest and differentiation in a human myeloid leukemia cell line

    DEFF Research Database (Denmark)

    Suzuki, Harukazu; Forrest, Alistair R R; van Nimwegen, Erik;

    2009-01-01

    Using deep sequencing (deepCAGE), the FANTOM4 study measured the genome-wide dynamics of transcription-start-site usage in the human monocytic cell line THP-1 throughout a time course of growth arrest and differentiation. Modeling the expression dynamics in terms of predicted cis-regulatory sites...

  12. Human Adipose Derived Stem Cells Induced Cell Apoptosis and S Phase Arrest in Bladder Tumor

    Directory of Open Access Journals (Sweden)

    Xi Yu

    2015-01-01

    Full Text Available The aim of this study was to determine the effect of human adipose derived stem cells (ADSCs on the viability and apoptosis of human bladder cancer cells. EJ and T24 cells were cocultured with ADSCs or cultured with conditioned medium of ADSCs (ADSC-CM, respectively. The cell counting and colony formation assay showed ADSCs inhibited the proliferation of EJ and T24 cells. Cell viability assessment revealed that the secretions of ADSCs, in the form of conditioned medium, were able to decrease cancer cell viability. Wound-healing assay suggested ADSC-CM suppressed migration of T24 and EJ cells. Moreover, the results of the flow cytometry indicated that ADSC-CM was capable of inducing apoptosis of T24 cells and inducing S phase cell cycle arrest. Western blot revealed ADSC-CM increased the expression of cleaved caspase-3 and cleaved PARP, indicating that ADSC-CM induced apoptosis in a caspase-dependent way. PTEN/PI3K/Akt pathway and Bcl-2 family proteins were involved in the mechanism of this reaction. Our study indicated that ADSCs may provide a promising and practicable manner for bladder tumor therapy.

  13. Boron neutron capture therapy induces cell cycle arrest and cell apoptosis of glioma stem/progenitor cells in vitro

    International Nuclear Information System (INIS)

    Glioma stem cells in the quiescent state are resistant to clinical radiation therapy. An almost inevitable glioma recurrence is due to the persistence of these cells. The high linear energy transfer associated with boron neutron capture therapy (BNCT) could kill quiescent and proliferative cells. The present study aimed to evaluate the effects of BNCT on glioma stem/progenitor cells in vitro. The damage induced by BNCT was assessed using cell cycle progression, apoptotic cell ratio and apoptosis-associated proteins expression. The surviving fraction and cell viability of glioma stem/progenitor cells were decreased compared with differentiated glioma cells using the same boronophenylalanine pretreatment and the same dose of neutron flux. BNCT induced cell cycle arrest in the G2/M phase and cell apoptosis via the mitochondrial pathway, with changes in the expression of associated proteins. Glioma stem/progenitor cells, which are resistant to current clinical radiotherapy, could be effectively killed by BNCT in vitro via cell cycle arrest and apoptosis using a prolonged neutron irradiation, although radiosensitivity of glioma stem/progenitor cells was decreased compared with differentiated glioma cells when using the same dose of thermal neutron exposure and boronophenylalanine pretreatment. Thus, BNCT could offer an appreciable therapeutic advantage to prevent tumor recurrence, and may become a promising treatment in recurrent glioma

  14. TopBP1 is required at mitosis to reduce transmission of DNA damage to G1 daughter cells

    DEFF Research Database (Denmark)

    Pedersen, Rune Troelsgaard; Kruse, Thomas; Nilsson, Jakob;

    2015-01-01

    mitotic entry. In early mitosis, TopBP1 marks sites of and promotes unscheduled DNA synthesis. Moreover, TopBP1 is required for focus formation of the structure-selective nuclease and scaffold protein SLX4 in mitosis. Persistent TopBP1 foci transition into 53BP1 nuclear bodies (NBs) in G1 and precise...... temporal depletion of TopBP1 just before mitotic entry induced formation of 53BP1 NBs in the next cell cycle, showing that TopBP1 acts to reduce transmission of DNA damage to G1 daughter cells. Based on these results, we propose that TopBP1 maintains genome integrity in mitosis by controlling chromatin...

  15. Radiation-induced apoptosis, necrosis and G2 arrest in Fadu and Hep2 cells

    International Nuclear Information System (INIS)

    Radiation damage is produced and viable cell number is reduced. We need to know the type of cell death by the ionizing radiation and the amount and duration of cell cycle arrest. In this study, we want to identified the main cause of the cellular damage in the oral cancer cells and normal keratinocytes with clinical useful radiation dosage. Human gingival tissue specimens obtained from healthy volunteers were used for primary culture of the normal human oral keratinocytes (NHOK). Primary NHOK were prepared from separated epithelial tissue and maintained in keratinocyte growth medium containing 0.15 mM calcium and a supplementary growth factor bullet kit as described previously. Fadu and Hep-2 cell lines were obtained from KCLB. Cells were irradiated in a (137) Cs gamma-irradiator at the dose of 10 Gy. The dose rate was 5.38 Gy/min. The necrotic cell death was examined with Lactate Dehydrogenase (LDH) activity in the culture medium. Every 4 day after irradiation, LDH activities were read and compared control group. Cell cycle phase distribution and preG1-incidence after radiation was analyzed by flow cytometry using Propidium Iodine (PI) staining. Cell cycle analysis were carried out with a FAC Star plus flowcytometry (FACS, Becton Dickinson, USA) and DNA histograms were processed with CELLFIT software (Becton Dickinson, USA). LDH activity increased in all of the experimental cells by the times. This pattern could be seen in the non-irradiated cells, and there was no difference between the non-irradiated cells and irradiated cells. We detected an induction of apoptosis after irradiation with a single dose of 10 Gy. The maximal rate of apoptosis ranged from 4.0% to 8.0% 4 days after irradiation. In all experimental cells, we detected G2/M arrest after irradiation with a single dose of 10 Gy. Yet there were differences in the number of G2/M arrested cells. The maximal rate of the G2/M ranges from 60.0% to 80.0% 24h after irradiation. There is no significant changes on

  16. Role of the retinoblastoma protein in cell cycle arrest mediated by a novel cell surface proliferation inhibitor

    Science.gov (United States)

    Enebo, D. J.; Fattaey, H. K.; Moos, P. J.; Johnson, T. C.; Spooner, B. S. (Principal Investigator)

    1994-01-01

    A novel cell regulatory sialoglycopeptide (CeReS-18), purified from the cell surface of bovine cerebral cortex cells has been shown to be a potent and reversible inhibitor of proliferation of a wide array of fibroblasts as well as epithelial-like cells and nontransformed and transformed cells. To investigate the possible mechanisms by which CeReS-18 exerts its inhibitory action, the effect of the inhibitor on the posttranslational regulation of the retinoblastoma susceptibility gene product (RB), a tumor suppressor gene, has been examined. It is shown that CeReS-18 mediated cell cycle arrest of both human diploid fibroblasts (HSBP) and mouse fibroblasts (Swiss 3T3) results in the maintenance of the RB protein in the hypophosphorylated state, consistent with a late G1 arrest site. Although their normal nontransformed counterparts are sensitive to cell cycle arrest mediated by CeReS-18, cell lines lacking a functional RB protein, through either genetic mutation or DNA tumor virus oncoprotein interaction, are less sensitive. The refractory nature of these cells is shown to be independent of specific surface receptors for the inhibitor, and another tumor suppressor gene (p53) does not appear to be involved in the CeReS-18 inhibition of cell proliferation. The requirement for a functional RB protein product, in order for CeReS-18 to mediate cell cycle arrest, is discussed in light of regulatory events associated with density-dependent growth inhibition.

  17. Retinoids arrest breast cancer cell proliferation: retinoic acid selectively reduces the duration of receptor tyrosine kinase signaling

    OpenAIRE

    Tighe, Ann P.; Talmage, David A

    2004-01-01

    Retinoic acid (RA) induces cell cycle arrest of hormone-dependent human breast cancer (HBC) cells. Previously, we demonstrated that RA-induced growth arrest of T-47D HBC cells required the activity of the RA-induced protein kinase, protein kinase Cα (PKCα) [J. Cell Physiol. 172 (1997) 306]. Here, we demonstrate that RA treatment of T-47D cells interfered with growth factor signaling to downstream, cytoplasmic and nuclear targets. RA treatment did not inhibit epidermal growth factor (EGF) rece...

  18. X-ray-induced G 2 arrest in ataxia telangiectasia lymphoblastoid cells

    International Nuclear Information System (INIS)

    Sensitivity to X-ray-induced G-2 arrest was compared between ataxia telangiectasia (AT) lymphoblastoid cells and normal human cells. Flow cytometrical analysis of cells following X-ray irradiation revealed that the fraction of cells with 4n DNA content was greater in AT cells than in normal cells as previously reported by other investigators. However, the other parameterss for cell-cycle progression kinetics including mitotic indices, cumulative mitotic indices and cumulative labelled mitotic indices indicated that X-ray-induced G-2 arrest as a function of dose in AT cells was indistinguishable from that in normal cells. Moreover, no significant difference in cell viability was noted between AT and normal cells until 48 h following X-irradiation up to 2.6 Gy, although X-irradiated At cells, compared to normal cells, showed a significantly decrease survival in terms of cell multiplication in growth medium and colony formation in soft agar. These data collectively suggest that the greater accumulation of AT cells with 4n DNA content in flow cytometry cannot be attributed to more stringent irreversible blockage of cell-cycle progression at the G-2 phase and eventual cell death there. The possible reasons for this greater accumulation are discussed. (Author). 19 refs.; 5 figs.; 2 tabs

  19. 2-Methoxyestradiol induces cell cycle arrest and apoptosis of nasopharyngeal carcinoma cells

    Institute of Scientific and Technical Information of China (English)

    Ning-ning ZHOU; Xiao-feng ZHU; Jun-ming ZHOU; Man-zhi LI; Xiao-shi ZHANG; Peng HUANG; Wen-qi JIANG

    2004-01-01

    AIM: To investigate 2-methoxyestradiol induced apoptosis and its mechanism of action in CNE2 cell lines.METHODS: CNE2 cells were cultured in RPMI-1640 medium and treated with 2-methoxyestradiol in different concentrations. MTT assay was used to detect growth inhibition. Flow cytometry and DNA ladders were used to detect apoptosis. Western blotting was used to observe the expression of p53, p21WAF1, Bax, and Bcl-2 protein.RESULTS: 2-methoxyestradiol inhibited proliferation of nasopharyngeal carcinoma CNE2 cells with IC50 value of2.82 μrnol/L. The results of flow cytometry showed an accumulation of CNE2 cells in G2/M phase in response to2-methoxyestradiol. Treatment of CNE2 cells with 2-methoxyestradiol resulted in DNA fragmentation. The expression levels of protein p53 and Bcl-2 decreased following 2-methoxyestradiol treatment in CNE2 cells, whereas Bax and p21WAF1 protein expression were unaffected after treatment with 2-methoxyestradiol. CONCLUSION:These results suggest that 2-methoxyestradiol induced cell cycle arrest at G2/M phase and apoptosis of CNE2 cells which was associated to Bcl-2 down-regulation.

  20. Synthesis, characterization, cytotoxicity, a poptosis and cell cycle arrest of dibenzoxanthenes derivatives

    Science.gov (United States)

    Wang, Xiu-Zhen; Yao, Jun-Hua; Jiang, Guang-Bin; Wang, Ji; Huang, Hong-Liang; Liu, Yun-Jun

    2014-12-01

    Two new dibenzoxanthenes compounds 1 and 2 have been synthesized and characterized by analytical and spectral methods. The crystal structure of compound 2 informs that the five rings of compound are almost planar. The DNA binding properties of two compounds were studied by absorption titration, viscosity measurement and luminescence. These results indicate that two compounds interact with calf thymus DNA through intercalative mode. Agarose gel electrophoresis experiment shows that PBR 322 DNA can be induced to cleave by two compounds under photoactivated condition. Compound 1 exhibits higher cytotoxicity than compound 2 toward MG-63, BEL-7402 and A549 cells. The apoptosis and cellular uptake of MG-63 cells were studied by fluorescence microscopy. Two compounds can also enhance the level of reactive oxygen species (ROS) and decrease the mitochondrial membrane potential. Compound 1 induces cell cycle arrest in G2/M phase and compound 2 induces cell cycle arrest in G0/G1 phase in MG-63.

  1. The centrosome protein NEDD1 as a potential pharmacological target to induce cell cycle arrest

    Directory of Open Access Journals (Sweden)

    Etievant Chantal

    2009-02-01

    Full Text Available Abstract Background NEDD1 is a protein that binds to the gamma-tubulin ring complex, a multiprotein complex at the centrosome and at the mitotic spindle that mediates the nucleation of microtubules. Results We show that NEDD1 is expressed at comparable levels in a variety of tumor-derived cell lines and untransformed cells. We demonstrate that silencing of NEDD1 expression by treatment with siRNA has differential effects on cells, depending on their status of p53 expression: p53-positive cells arrest in G1, whereas p53-negative cells arrest in mitosis with predominantly aberrant monopolar spindles. However, both p53-positive and -negative cells arrest in mitosis if treated with low doses of siRNA against NEDD1 combined with low doses of the inhibitor BI2536 against the mitotic kinase Plk1. Simultaneous reduction of NEDD1 levels and inhibition of Plk1 act in a synergistic manner, by potentiating the anti-mitotic activity of each treatment. Conclusion We propose that NEDD1 may be a promising target for controlling cell proliferation, in particular if targeted in combination with Plk1 inhibitors.

  2. Somatostatin receptor-1 induces cell cycle arrest and inhibits tumor growth in pancreatic cancer.

    Science.gov (United States)

    Li, Min; Wang, Xiaochi; Li, Wei; Li, Fei; Yang, Hui; Wang, Hao; Brunicardi, F Charles; Chen, Changyi; Yao, Qizhi; Fisher, William E

    2008-11-01

    Functional somatostatin receptors (SSTR) are lost in human pancreatic cancer. Transfection of SSTR-1 inhibited pancreatic cancer cell proliferation in vitro. We hypothesize that stable transfection of SSTR-1 may inhibit pancreatic cancer growth in vivo possibly through cell cycle arrest. In this study, we examined the expression of SSTR-1 mRNA in human pancreatic cancer tissue specimens, and investigated the effect of SSTR-1 overexpression on cell proliferation, cell cycle, and tumor growth in a subcutaneous nude mouse model. We found that SSTR-1 mRNA was downregulated in the majority of pancreatic cancer tissue specimens. Transfection of SSTR-1 caused cell cycle arrest at the G(0)/G(1) growth phase, with a corresponding decline of cells in the S (mitotic) phase. The overexpression of SSTR-1 significantly inhibited subcutaneous tumor size by 71% and 43% (n = 5, P < 0.05, Student's t-test), and inhibited tumor weight by 69% and 47% (n = 5, P < 0.05, Student's t-test), in Panc-SSTR-1 and MIA-SSTR-1 groups, respectively, indicating the potent inhibitory effect of SSTR-1 on pancreatic cancer growth. Our data demonstrate that overexpression of SSTR-1 significantly inhibits pancreatic cancer growth possibly through cell cycle arrest. This study suggests that gene therapy with SSTR-1 may be a potential adjuvant treatment for pancreatic cancer. PMID:18823376

  3. Respiratory syncytial virus matrix protein induces lung epithelial cell cycle arrest through a p53 dependent pathway.

    Science.gov (United States)

    Bian, Tao; Gibbs, John D; Örvell, Claes; Imani, Farhad

    2012-01-01

    Respiratory syncytial virus (RSV) is the major cause of viral respiratory infections in children. Our previous study showed that the RSV infection induced lung epithelial cell cycle arrest, which enhanced virus replication. To address the mechanism of RSV-induced cell cycle arrest, we examined the contribution of RSV-matrix (RSV-M) protein. In this report, we show that in both the A549 cell line and primary human bronchial epithelial (PHBE) cells, transfection with RSV-M protein caused the cells to proliferate at a slower rate than in control cells. The cell cycle analysis showed that RSV-M protein induced G1 phase arrest in A549 cells, and G1 and G2/M phase arrest in PHBE cells. Interestingly, RSV-M expression induced p53 and p21 accumulation and decreased phosphorylation of retinoblastoma protein (Rb). Further, induction of cell cycle arrest by RSV-M was not observed in a p53-deficient epithelial cell line (H1299). However, cell cycle arrest was restored after transfection of p53 cDNA into H1299 cells. Taken together, these results indicate that RSV-M protein regulates lung epithelial cell cycle through a p53-dependent pathway, which enhances RSV replication. PMID:22662266

  4. Respiratory syncytial virus matrix protein induces lung epithelial cell cycle arrest through a p53 dependent pathway.

    Directory of Open Access Journals (Sweden)

    Tao Bian

    Full Text Available Respiratory syncytial virus (RSV is the major cause of viral respiratory infections in children. Our previous study showed that the RSV infection induced lung epithelial cell cycle arrest, which enhanced virus replication. To address the mechanism of RSV-induced cell cycle arrest, we examined the contribution of RSV-matrix (RSV-M protein. In this report, we show that in both the A549 cell line and primary human bronchial epithelial (PHBE cells, transfection with RSV-M protein caused the cells to proliferate at a slower rate than in control cells. The cell cycle analysis showed that RSV-M protein induced G1 phase arrest in A549 cells, and G1 and G2/M phase arrest in PHBE cells. Interestingly, RSV-M expression induced p53 and p21 accumulation and decreased phosphorylation of retinoblastoma protein (Rb. Further, induction of cell cycle arrest by RSV-M was not observed in a p53-deficient epithelial cell line (H1299. However, cell cycle arrest was restored after transfection of p53 cDNA into H1299 cells. Taken together, these results indicate that RSV-M protein regulates lung epithelial cell cycle through a p53-dependent pathway, which enhances RSV replication.

  5. Cell cycle arrest and apoptosis, two alternative mechanisms for PMKT2 killer activity.

    Science.gov (United States)

    Santos, Antonio; Alonso, Alejandro; Belda, Ignacio; Marquina, Domingo

    2013-01-01

    Pichia membranifaciens CYC 1086 secretes a unique 30kDa killer toxin (PMKT2) that inhibits a variety of spoilage yeasts and fungi of agronomical interest. The cytocidal effect of PMKT2 on Saccharomyces cerevisiae cells was studied. Metabolic events associated with the loss of S. cerevisiae viability caused by PMKT2 were qualitatively identical to those reported for K28 killer toxin activity, but different to those reported for PMKT. At higher doses, none of the cellular events accounting for the action of PMKT, the killer toxin secreted by P. membranifaciens CYC 1106, was observed for PMKT2. Potassium leakage, sodium influx and the decrease of intracellular pH were not among the primary effects of PMKT2. We report here that this protein is unable to form ion-permeable channels in liposome membranes, suggesting that channel formation is not the mechanism of cytotoxic action of PMKT2. Nevertheless, flow cytometry studies have revealed a cell cycle arrest at an early S-phase with an immature bud and pre-replicated 1n DNA content. By testing the sensitivity of cells arrested at different stages in the cell cycle, we hoped to identify the execution point for lethality more precisely. Cells arrested at the G1-phase by α-factor or arrested at G2-phase by the spindle poison methyl benzimidazol-2-yl-carbamate (MBC) were protected against the toxin. Cells released from the arrest in both cases were killed by PMKT2 at a similar rate. Nevertheless, cells released from MBC-arrest were able to grow for a short time, and then viability dropped rapidly. These findings suggest that cells released from G2-phase are initially able to divide, but die in the presence of PMKT2 after initiating the S-phase in a new cycle, adopting a terminal phenotype within that cycle. By contrast, low doses of PMKT and PMKT2 were able to generate the same cellular response. The evidence presented here shows that treating yeast with low doses of PMKT2 leads to the typical membranous, cytoplasmic

  6. Mitochondrial Malfunctioning, Proteasome Arrest and Apoptosis in Cancer Cells by Focused Intracellular Generation of Oxygen Radicals

    Directory of Open Access Journals (Sweden)

    Ilaria Postiglione

    2015-08-01

    Full Text Available Photofrin/photodynamic therapy (PDT at sub-lethal doses induced a transient stall in proteasome activity in surviving A549 (p53+/+ and H1299 (p53−/− cells as indicated by the time-dependent decline/recovery of chymotrypsin-like activity. Indeed, within 3 h of incubation, Photofrin invaded the cytoplasm and localized preferentially within the mitochondria. Its light activation determined a decrease in mitochondrial membrane potential and a reversible arrest in proteasomal activity. A similar result is obtained by treating cells with Antimycin and Rotenone, indicating, as a common denominator of this effect, the ATP decrease. Both inhibitors, however, were more toxic to cells as the recovery of proteasomal activity was incomplete. We evaluated whether combining PDT (which is a treatment for killing tumor cells, per se, and inducing proteasome arrest in the surviving ones with Bortezomib doses capable of sustaining the stall would protract the arrest with sufficient time to induce apoptosis in remaining cells. The evaluation of the mitochondrial membrane depolarization, residual proteasome and mitochondrial enzymatic activities, colony-forming capabilities, and changes in protein expression profiles in A549 and H1299 cells under a combined therapeutic regimen gave results consistent with our hypothesis.

  7. Cell cycle arrest biomarkers in human lung cancer cells after treatment with selenium in culture.

    Science.gov (United States)

    Swede, Helen; Dong, Yan; Reid, Mary; Marshall, James; Ip, Clement

    2003-11-01

    In the planning of future intervention trials using chemopreventive agents against lung cancer, it is critical to evaluate the effect on biomarkers implicated specifically in lung carcinogenesis. With the use of the H520 and H522 human lung cancer cell lines, the present study showed that treatment with selenium (in the form of methylseleninic acid) inhibited cell growth, arrested cell cycle progression at G(1), and induced apoptosis as a late event. Because H520 cells were more sensitive to selenium than H522 cells (IC(50) of MSA was 2.5 or 10 micro M for H520 or H522 cells, respectively, at 24 h), a panel of nine cell cycle regulatory proteins known to be involved in G(1)-->S transition was assessed by Western analysis using whole cell lysate from H520 cells. These nine proteins (DP1, cdc25A, cyclin A, cyclin B(1), cyclin D(1), cdk1, cdk5, p21(WAF1), and GADD153) have been reported previously by our laboratory to be modulated by MSA in human breast and prostate cancer cells. Our data showed that only four (DP1, cdc25A, p21(WAF1), and GADD153) of nine biomarkers produced the expected changes after treatment of lung cancer cells with MSA. This finding raises the possibility that the molecular targets sensitive to selenium modulation may be tissue specific. Thus, the selection of selenium biomarkers for evaluation in an intervention trial must be based on empirical data derived from the cancer cell type of interest. PMID:14652289

  8. Absence of p53 in Clara cells favours multinucleation and loss of cell cycle arrest

    Directory of Open Access Journals (Sweden)

    Clarke Alan R

    2002-11-01

    Full Text Available Abstract Background The p53 oncosuppressor protein is a critical mediator of the response to injury in mammalian cells and is mutationally inactivated in the majority of lung malignancies. In this analysis, the effects of p53-deficiency were investigated in short-term primary cultures of murine bronchiolar Clara cells. Clara cells, isolated from gene-targeted p53-deficient mice, were compared to cells derived from wild type littermates. Results p53 null cultures displayed abnormal morphology; specifically, a high incidence of multinucleation, which increased with time in culture. Multinucleated cells were proficient in S phase DNA synthesis, as determined by BrdU incorporation. However, multinucleation did not reflect altered rates of S phase synthesis, which were similar between wild type and p53-/- cultures. Nucleation defects in p53-/- Clara cells associated with increased centrosome number, as determined by confocal microscopy of pericentrin-stained cultures, and may highlight a novel role of p53 in preserving genomic integrity in lung epithelial cells. Effects of p53-deficiency were also studied following exposure to DNA damage. A p53-dependent reduction in the BrdU index was observed in Clara cells following ionizing radiation. The reduction in BrdU index in wild type cells displayed serum-dependency, and occurred only in the absence of serum. Taken together, these findings demonstrate that in murine primary Clara cell culture, cell cycle arrest is a p53-mediated response to DNA damage, and that extracellular factors, such as serum, influence this response. Conclusion These findings highlight functions of wild type p53 protein in bipolar spindle formation, centrosome regulation, and growth control in bronchiolar Clara cells.

  9. Role of Baculovirus IE2 and Its RING Finger in Cell Cycle Arrest

    OpenAIRE

    Prikhod’ko, Elena A.; Miller, Lois K.

    1998-01-01

    The ie2 gene of Autographa californica nuclear polyhedrosis virus (AcMNPV) is known to transactivate transient expression from viral promoters in a host cell-specific manner. We report that transfection of Spodoptera frugiperda (SF-21) cells with ie2 was sufficient to arrest the cell cycle, resulting in the accumulation of enlarged cells with abnormally high DNA contents. By 72 h posttransfection, more than 50% of ie2-transfected cells had DNA contents greater than 4N. There was no evidence o...

  10. Divergence to apoptosis from ROS induced cell cycle arrest: Effect of cadmium

    Energy Technology Data Exchange (ETDEWEB)

    Chatterjee, Soumya; Kundu, Subhadip; Sengupta, Suman [Department of Environmental Science, University of Kalyani, West Bengal 741235 (India); Department of Zoology, University of Calcutta, Calcutta-700019, West Bengal (India); Bhattacharyya, Arindam, E-mail: arindam19@yahoo.com [Department of Environmental Science, University of Kalyani, West Bengal 741235 (India); Department of Zoology, University of Calcutta, Calcutta-700019, West Bengal (India)

    2009-04-26

    Recently, the role of cadmium (Cd) in immunosupression has gained importance. Nevertheless, the signaling pathways underlying cadmium-induced immune cell death remains largely unclear. In accordance to our previous in vivo report, and to evaluate the further details of the mechanism, we have investigated the effects of cadmium (CdCl{sub 2}, H{sub 2}O) on cell cycle regulation and apoptosis in splenocytes in vitro. Our results have revealed that reactive oxygen species (ROS) and p21 are involved in cell cycle arrest in a p53 independent manner but late hour apoptotic response was accompanied by the p53 up-regulation, loss of mitochondrial transmembrane potential (MTP), down-regulation of Bcl-xl, activation of caspase-3 and release of cytochrome c (Cyt c). However, pifithrin alfa (PFT-{alpha}), an inhibitor of p53, fails to rescue the cells from the cadmium-induced cell cycle arrest but prevents Bcl-xl down-regulation and loss of {Delta}{psi}{sub m}, which indicates that there is an involvement of p53 in apoptosis. In contrast, treatment with N-acetyl cysteine (NAC) can prevent cell cycle arrest and p21 up-regulation at early hours. Although it is clear that, NAC has no effect on apoptosis, p53 expression and MPT changes at late stage events. Taken together, we have demonstrated that cadmium promotes ROS generation, which potently initiates the cell cycle arrest at early hours and finally induces p53-dependent apoptosis at later part of the event.

  11. Silencing NOTCH signaling causes growth arrest in both breast cancer stem cells and breast cancer cells

    Science.gov (United States)

    Suman, S; Das, T P; Damodaran, C

    2013-01-01

    Background: Breast cancer stem cells (BCSCs) are characterized by high aldehyde dehydrogenase (ALDH) enzyme activity and are refractory to current treatment modalities, show a higher risk for metastasis, and influence the epithelial to mesenchymal transition (EMT), leading to a shorter time to recurrence and death. In this study, we focused on examination of the mechanism of action of a small herbal molecule, psoralidin (Pso) that has been shown to effectively suppress the growth of BSCSs and breast cancer cells (BCCs), in breast cancer (BC) models. Methods: ALDH− and ALDH+ BCCs were isolated from MDA-MB-231 cells, and the anticancer effects of Pso were measured using cell viability, apoptosis, colony formation, invasion, migration, mammosphere formation, immunofluorescence, and western blot analysis. Results: Psoralidin significantly downregulated NOTCH1 signaling, and this downregulation resulted in growth inhibition and induction of apoptosis in both ALDH− and ALDH+ cells. Molecularly, Pso inhibited NOTCH1 signaling, which facilitated inhibition of EMT markers (β-catenin and vimentin) and upregulated E-cadherin expression, resulting in reduced migration and invasion of both ALDH− and ALDH+ cells. Conclusion: Together, our results suggest that inhibition of NOTCH1 by Pso resulted in growth arrest and inhibition of EMT in BCSCs and BCCs. Psoralidin appears to be a novel agent that targets both BCSCs and BCCs. PMID:24129237

  12. CRIF1 interacting with CDK2 regulates bone marrow microenvironment-induced G0/G1 arrest of leukemia cells.

    Directory of Open Access Journals (Sweden)

    Qian Ran

    Full Text Available BACKGROUND: To assess the level of CR6-interacting factor 1 (CRIF1, a cell cycle negative regulator, in patients with leukemia and investigate the role of CRIF1 in regulating leukemia cell cycle. METHODS: We compared the CRIF1 level in bone marrow (BM samples from healthy and acute myeloid leukemia (AML, iron deficiency anemia (IDA and AML-complete remission (AML-CR subjects. We also manipulated CRIF1 level in the Jurkat cells using lentivirus-mediated overexpression or siRNA-mediated depletion. Co-culture with the BM stromal cells (BMSCs was used to induce leukemia cell cycle arrest and mimic the BM microenvironment. RESULTS: We found significant decreases of CRIF1 mRNA and protein in the AML group. CRIF1 overexpression increased the proportion of Jurkat cells arrested in G0/G1, while depletion of endogenous CRIF1 decreased cell cycle arrest. Depletion of CRIF1 reversed BMSCs induced cell cycle arrest in leukemia cells. Co-immunoprecipitation showed a specific binding of CDK2 to CRIF1 in Jurkat cells during cell cycle arrest. Co-localization of two proteins in both nucleus and cytoplasm was also observed with immunofluorescent staining. CONCLUSION: CRIF1 may play a regulatory role in the BM microenvironment-induced leukemia cell cycle arrest possibly through interacting with CDK2 and acting as a cyclin-dependent kinase inhibitor.

  13. Nucleostemin Depletion Induces Post-G1 Arrest Apoptosis in Chronic Myelogenous Leukemia K562 Cells

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    Negin Seyed-Gogani

    2013-12-01

    Full Text Available Purpose: Despite significant improvements in treatment of chronic myelogenous leukemia (CML, the emergence of leukemic stem cell (LSC concept questioned efficacy of current therapeutical protocols. Remaining issue on CML includes finding and targeting of the key genes responsible for self-renewal and proliferation of LSCs. Nucleostemin (NS is a new protein localized in the nucleolus of most stem cells and tumor cells which regulates their self-renewal and cell cycle progression. The aim of this study was to investigate effects of NS knocking down in K562 cell line as an in vitro model of CML. Methods: NS gene silencing was performed using a specific small interfering RNA (NS-siRNA. The gene expression level of NS was evaluated by RT-PCR. The viability and growth rate of K562 cells were determined by trypan blue exclusion test. Cell cycle distribution of the cells was analyzed by flow cytometry. Results: Our results showed that NS knocking down inhibited proliferation and viability of K562 cells in a time-dependent manner. Cell cycle studies revealed that NS depletion resulted in G1 cell cycle arrest at short times of transfection (24 h followed with apoptosis at longer times (48 and 72 h, suggest that post-G1 arrest apoptosis is occurred in K562 cells. Conclusion: Overall, these results point to essential role of NS in K562 cells, thus, this gene might be considered as a promising target for treatment of CML.

  14. 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

  15. Postnatal telomere dysfunction induces cardiomyocyte cell-cycle arrest through p21 activation.

    Science.gov (United States)

    Aix, Esther; Gutiérrez-Gutiérrez, Óscar; Sánchez-Ferrer, Carlota; Aguado, Tania; Flores, Ignacio

    2016-06-01

    The molecular mechanisms that drive mammalian cardiomyocytes out of the cell cycle soon after birth remain largely unknown. Here, we identify telomere dysfunction as a critical physiological signal for cardiomyocyte cell-cycle arrest. We show that telomerase activity and cardiomyocyte telomere length decrease sharply in wild-type mouse hearts after birth, resulting in cardiomyocytes with dysfunctional telomeres and anaphase bridges and positive for the cell-cycle arrest protein p21. We further show that premature telomere dysfunction pushes cardiomyocytes out of the cell cycle. Cardiomyocytes from telomerase-deficient mice with dysfunctional telomeres (G3 Terc(-/-)) show precocious development of anaphase-bridge formation, p21 up-regulation, and binucleation. In line with these findings, the cardiomyocyte proliferative response after cardiac injury was lost in G3 Terc(-/-) newborns but rescued in G3 Terc(-/-)/p21(-/-) mice. These results reveal telomere dysfunction as a crucial signal for cardiomyocyte cell-cycle arrest after birth and suggest interventions to augment the regeneration capacity of mammalian hearts. PMID:27241915

  16. Berberine, a genotoxic alkaloid, induces ATM-Chk1 mediated G2 arrest in prostate cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Wang Yu; Liu Qiao; Liu Zhaojian; Li Boxuan; Sun Zhaoliang; Zhou Haibin; Zhang Xiyu; Gong Yaoqin [Ministry of Education Key Laboratory of Experimental Teratology and Institute of Molecular Medicine and Genetics, Shandong University School of Medicine, Jinan (China); Shao Changshun, E-mail: changshun.shao@gmail.com [Ministry of Education Key Laboratory of Experimental Teratology and Institute of Molecular Medicine and Genetics, Shandong University School of Medicine, Jinan (China)

    2012-06-01

    Berberine has been shown to possess anti-tumor activity against a wide spectrum of cancer cells. It inhibits cancer cell proliferation by inducing cell cycle arrest, at G1 and/or G2/M, and apoptosis. While it has been documented that berberine induces G1 arrest by activating the p53-p21 cascade, it remains unclear what mechanism underlies the berberine-induced G2/M arrest, which is p53-independent. In this study, we tested the anti-proliferative effect of berberine on murine prostate cancer cell line RM-1 and characterized the underlying mechanisms. Berberine dose-dependently induced DNA double-strand breaks and apoptosis. At low concentrations, berberine was observed to induce G1 arrest, concomitant with the activation of p53-p21 cascade. Upon exposure to berberine at a higher concentration (50 {mu}M) for 24 h, cells exhibited G2/M arrest. Pharmacological inhibition of ATM by KU55933, or Chk1 by UCN-01, could efficiently abrogate the G2/M arrest in berberine-treated cells. Downregulation of Chk1 by RNA interference also abolished the G2/M arrest caused by berberine, confirming the role of Chk1 in the pathway leading to G2/M arrest. Abrogation of G2/M arrest by ATM inhibition forced more cells to undergo apoptosis in response to berberine treatment. Chk1 inhibition by UCN-01, on the other hand, rendered cells more sensitive to berberine only when p53 was inhibited. Our results suggest that combined administration of berberine and caffeine, or other ATM inhibitor, may accelerate the killing of cancer cells.

  17. Lysophosphatidate induces chemo-resistance by releasing breast cancer cells from taxol-induced mitotic arrest.

    Directory of Open Access Journals (Sweden)

    Nasser Samadi

    Full Text Available BACKGROUND: Taxol is a microtubule stabilizing agent that arrests cells in mitosis leading to cell death. Taxol is widely used to treat breast cancer, but resistance occurs in 25-69% of patients and it is vital to understand how Taxol resistance develops to improve chemotherapy. The effects of chemotherapeutic agents are overcome by survival signals that cancer cells receive. We focused our studies on autotaxin, which is a secreted protein that increases tumor growth, aggressiveness, angiogenesis and metastasis. We discovered that autotaxin strongly antagonizes the Taxol-induced killing of breast cancer and melanoma cells by converting the abundant extra-cellular lipid, lysophosphatidylcholine, into lysophosphatidate. This lipid stimulates specific G-protein coupled receptors that activate survival signals. METHODOLOGY/PRINCIPAL FINDINGS: In this study we determined the basis of these antagonistic actions of lysophosphatidate towards Taxol-induced G2/M arrest and cell death using cultured breast cancer cells. Lysophosphatidate does not antagonize Taxol action in MCF-7 cells by increasing Taxol metabolism or its expulsion through multi-drug resistance transporters. Lysophosphatidate does not lower the percentage of cells accumulating in G2/M by decreasing exit from S-phase or selective stimulation of cell death in G2/M. Instead, LPA had an unexpected and remarkable action in enabling MCF-7 and MDA-MB-468 cells, which had been arrested in G2/M by Taxol, to normalize spindle structure and divide, thus avoiding cell death. This action involves displacement of Taxol from the tubulin polymer fraction, which based on inhibitor studies, depends on activation of LPA receptors and phosphatidylinositol 3-kinase. CONCLUSIONS/SIGNIFICANCE: This work demonstrates a previously unknown consequence of lysophosphatidate action that explains why autotaxin and lysophosphatidate protect against Taxol-induced cell death and promote resistance to the action of this

  18. Antiproliferative effect of rapamycin on human T-cell leukemia cell line Jurkat by cell cycle arrest and telomerase inhibition

    Institute of Scientific and Technical Information of China (English)

    Yan-min ZHAO; Qian ZHOU; Yun XU; Xiao-yu LAI; He HUANG

    2008-01-01

    Aim:To examine the ability of rapamycin to suppress growth and regulate telomerase activity in the human T-cell leukemia cell line Jurkat. Methods:Cell proliferation was assessed after exposure to rapamycin by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Cell cycle progression and apoptosis were determined by flow cytometry. The proteins important for cell cycle progres-sion and Akt/mammalian target of rapamycin signaling cascade were assessed by Western blotting. Telomerase activity was quantified by telomeric repeat amplication protocol assay. The human telomerase reverse transcriptase (hTERT) mRNA levels were determined by semi-quantitative RT-PCR. Results:Rapamycin inhibited the proliferation of Jurkat, induced G1 phase arrest, unregulated the pro-tein level of p21 as well as p27, and downregulated cyclinD3, phospho-p70s6k, and phospho-s6, but had no effect on apoptosis. Treatment with rapamycin reduced telomerase activity, and reduced hTERT mRNA and protein expression. Conclusion:Rapamycin displayed a potent antileukemic effect in the human T-cell leukemia cell line by inhibition of cell proliferation through G1 cell cycle arrest and also through the suppression of telomerase activity, suggesting that rapamycin may have potential clinical implications in the treatment of some leukemias.

  19. Interference with Ca2+ release activated Ca2+ (CRAC) channel function delays T-cell arrest in vivo

    OpenAIRE

    Waite, Janelle C.; Vardhana, Santosh; Shaw, Patrick J.; Jang, Jung-Eun; McCarl, Christie-Ann; Cameron, Thomas O; Feske, Stefan; Dustin, Michael L

    2013-01-01

    Entry of lymphocytes into secondary lymphoid organs (SLOs) involves intravascular arrest and intracellular calcium ion ([Ca2+]i) elevation. TCR activation triggers increased [Ca2+]i and can arrest T-cell motility in vitro. However the requirement for [Ca2+]i elevation in arresting T cells in vivo has not been tested. Here, we have manipulated the Ca2+ release-activated Ca2+ (CRAC) channel pathway required for [Ca2+]i elevation in T cells through genetic deletion of stromal interaction molecul...

  20. 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...

  1. Radiosensitization of NSCLC cells by EGFR inhibition is the result of an enhanced p53-dependent G1 arrest

    International Nuclear Information System (INIS)

    Purpose: How EGF receptor (EGFR) inhibition induces cellular radiosensitization and with that increase in tumor control is still a matter of discussion. Since EGFR predominantly regulates cell cycle and proliferation, we studied whether a G1-arrest caused by EGFR inhibition may contribute to these effects. Materials and methods: We analyzed human non-small cell lung cancer (NSCLC) cell lines either wild type (wt) or mutated in p53 (A549, H460, vs. H1299, H3122) and HCT116 cells (p21 wt and negative). EGFR was inhibited by BIBX1382BS, erlotinib or cetuximab; p21 was knocked down by siRNA. Functional endpoints analyzed were cell signaling, proliferation, G1-arrest, cell survival as well as tumor control using an A549 tumor model. Results: When combined with IR, EGFR inhibition enhances the radiation-induced permanent G1 arrest, though solely in cells with intact p53/p21 signaling. This increase in G1-arrest was always associated with enhanced cellular radiosensitivity. Strikingly, this effect was abrogated when cells were re-stimulated, suggesting the initiation of dormancy. In line with this, only a small non-significant increase in tumor control was observed for A549 tumors treated with fractionated RT and EGFR inhibition. Conclusion: For NSCLC cells increase in radiosensitivity by EGFR inhibition results from enhanced G1-arrest. However, this effect does not lead to improved tumor control because cells can be released from this arrest by re-stimulation

  2. Deoxyelephantopin from Elephantopus scaber L. induces cell-cycle arrest and apoptosis in the human nasopharyngeal cancer CNE cells

    International Nuclear Information System (INIS)

    Highlights: → Deoxyelephantopin (ESD) inhibited cell proliferation in the human nasopharyngeal cancer CNE cells. → ESD induced cell cycle arrest in S and G2/M phases via modulation of cell cycle regulatory proteins. → ESD triggered apoptosis by dysfunction of mitochondria and induction of both intrinsic and extrinsic apoptotic signaling pathways. → ESD also triggered Akt, ERK, and JNK signaling pathways. -- Abstract: Deoxyelephantopin (ESD), a naturally occurring sesquiterpene lactone present in the Chinese medicinal herb, Elephantopus scaber L. exerted anticancer effects on various cultured cancer cells. However, the cellular mechanisms by which it controls the development of the cancer cells are unavailable, particularly the human nasopharyngeal cancer CNE cells. In this study, we found that ESD inhibited the CNE cell proliferation. Cell cycle arrest in S and G2/M phases was also found. Western blotting analysis showed that modulation of cell cycle regulatory proteins was responsible for the ESD-induced cell cycle arrest. Besides, ESD also triggered apoptosis in CNE cells. Dysfunction in mitochondria was found to be associated with the ESD-induced apoptosis as evidenced by the loss of mitochondrial membrane potential (ΔΨm), the translocation of cytochrome c, and the regulation of Bcl-2 family proteins. Despite the Western blotting analysis showed that both intrinsic and extrinsic apoptotic pathways (cleavage of caspases-3, -7, -8, -9, and -10) were triggered in the ESD-induced apoptosis, additional analysis also showed that the induction of apoptosis could be achieved by the caspase-independent manner. Besides, Akt, ERK and JNK pathways were found to involve in ESD-induced cell death. Overall, our findings provided the first evidence that ESD induced cell cycle arrest, and apoptosis in CNE cells. ESD could be a potential chemotherapeutic agent in the treatment of nasopharyngeal cancer (NPC).

  3. Sulforaphane induces cell cycle arrest and apoptosis in acute lymphoblastic leukemia cells.

    Directory of Open Access Journals (Sweden)

    Koramit Suppipat

    Full Text Available Acute lymphoblastic leukemia (ALL is the most common hematological cancer in children. Although risk-adaptive therapy, CNS-directed chemotherapy, and supportive care have improved the survival of ALL patients, disease relapse is still the leading cause of cancer-related death in children. Therefore, new drugs are needed as frontline treatments in high-risk disease and as salvage agents in relapsed ALL. In this study, we report that purified sulforaphane, a natural isothiocyanate found in cruciferous vegetables, has anti-leukemic properties in a broad range of ALL cell lines and primary lymphoblasts from pediatric T-ALL and pre-B ALL patients. The treatment of ALL leukemic cells with sulforaphane resulted in dose-dependent apoptosis and G2/M cell cycle arrest, which was associated with the activation of caspases (3, 8, and 9, inactivation of PARP, p53-independent upregulation of p21(CIP1/WAF1, and inhibition of the Cdc2/Cyclin B1 complex. Interestingly, sulforaphane also inhibited the AKT and mTOR survival pathways in most of the tested cell lines by lowering the levels of both total and phosphorylated proteins. Finally, the administration of sulforaphane to the ALL xenograft models resulted in a reduction of tumor burden, particularly following oral administration, suggesting a potential role as an adjunctive agent to improve the therapeutic response in high-risk ALL patients with activated AKT signaling.

  4. Withaferin-A induces mitotic catastrophe and growth arrest in prostate cancer cells

    Science.gov (United States)

    Roy, Ram V; Suman, Suman; Das, Trinath P.; Luevano, Joe; Damodaran, Chendil

    2014-01-01

    Cell cycle deregulation is strongly associated with the pathogenesis of prostate cancer (CaP). Clinical trials of cell cycle regulators that target either the G0/G1 or G2/M phase to inhibit the growth of cancers including CaP are increasing. In this study, we determined the cell-cycle regulatory potential of the herbal molecule Withaferin-A (WA) on CaP cells. WA induced irreversible G2/M arrest in both CaP cell lines (PC3 and DU145) for 48 h. The G2/M arrest was accompanied by upregulation of phosphorylated Wee1, phophorylated histone H3, p21 and Aurora-B. On the other hand, downregulation of cyclins (E2, A, and B1) and phorphorylated Cdc2 (Tyr15) was observed in WA-treated CaP cells. In addition, decreased levels of phosphorylated Chk1 (Ser345) and Chk2 (Thr68) were evident in WA-treated CaP cells. Our results suggest that activation of Cdc2 leads to accumulation in M-phase, with abnormal duplication, and initiation of mitotic catastrophe that results in cell death. In conclusion, these results clearly highlight the potential of WA as a regulator of the G2/M phase of the cell cycle and as a therapeutic agent for CaP. PMID:24079846

  5. Knockdown of human deubiquitinase PSMD14 induces cell cycle arrest and senescence

    Energy Technology Data Exchange (ETDEWEB)

    Byrne, Ann; McLaren, Rajashree P.; Mason, Paul; Chai, Lilly; Dufault, Michael R.; Huang, Yinyin; Liang, Beirong; Gans, Joseph D.; Zhang, Mindy; Carter, Kara; Gladysheva, Tatiana B.; Teicher, Beverly A.; Biemann, Hans-Peter N.; Booker, Michael; Goldberg, Mark A.; Klinger, Katherine W.; Lillie, James [Genzyme Corporation, 49 New York Avenue, Framingham, MA 01701 (United States); Madden, Stephen L., E-mail: steve.madden@genzyme.com [Genzyme Corporation, 49 New York Avenue, Framingham, MA 01701 (United States); Jiang, Yide, E-mail: yide.jiang@genzyme.com [Genzyme Corporation, 49 New York Avenue, Framingham, MA 01701 (United States)

    2010-01-15

    The PSMD14 (POH1, also known as Rpn11/MPR1/S13/CepP1) protein within the 19S complex (19S cap; PA700) is responsible for substrate deubiquitination during proteasomal degradation. The role of PSMD14 in cell proliferation and senescence was explored using siRNA knockdown in carcinoma cell lines. Our results reveal that down-regulation of PSMD14 by siRNA transfection had a considerable impact on cell viability causing cell arrest in the G0-G1 phase, ultimately leading to senescence. The molecular events associated with decreased cell proliferation, cell cycle arrest and senescence include down-regulation of cyclin B1-CDK1-CDC25C, down-regulation of cyclin D1 and up-regulation of p21{sup /Cip} and p27{sup /Kip1}. Most notably, phosphorylation of the retinoblastoma protein was markedly reduced in PSMD14 knockdown cells. A comparative study with PSMB5, a subunit of the 20S proteasome, revealed that PSMB5 and PSMD14 have different effects on cell cycle, senescence and associated molecular events. These data support the view that the 19S and 20S subunits of the proteasome have distinct biological functions and imply that targeting 19S and 20S would have distinct molecular consequences on tumor cells.

  6. A novel peptide sansalvamide analogue inhibits pancreatic cancer cell growth through G0/G1 cell-cycle arrest

    International Nuclear Information System (INIS)

    Patients with pancreatic cancer have little hope for cure because no effective therapies are available. Sansalvamide A is a cyclic depsipeptide produced by a marine fungus. We investigated the effect of a novel sansalvamide A analogue on growth, cell-cycle phases, and induction of apoptosis in human pancreatic cancer cells in vitro. The sansalvamide analogue caused marked time- and concentration-dependent inhibition of DNA synthesis and cell proliferation of two human pancreatic cancer cell lines (AsPC-1 and S2-013). The analogue induced G0/G1 phase cell-cycle arrest and morphological changes suggesting induction of apoptosis. Apoptosis was confirmed by annexin V binding. This novel sansalvamide analogue inhibits growth of pancreatic cancer cells through G0/G1 arrest and induces apoptosis. Sansalvamide analogues may be valuable for the treatment of pancreatic cancer

  7. RRR-α-tocopheryl succinate inhibits human gastric cancer SGC-7901 cell growth by inducing apoptosis and DNA synthesis arrest

    OpenAIRE

    Wu, Kun; ZHAO Yan; Liu, Bai-He; Li, Yao; Liu, Fang; Guo, Jian; Yu, Wei-Ping

    2002-01-01

    AIM: To investigate the effects of growth inhibition of human gastric cancer SGC-7901 cell with RRR-α-tocopheryl succinate (VES), a derivative of natural Vitamin E, via inducing apoptosis and DNA synthesis arrest.

  8. Sulforaphane induces cell cycle arrest by protecting RB-E2F-1 complex in epithelial ovarian cancer cells

    Directory of Open Access Journals (Sweden)

    Morris Robert

    2010-03-01

    Full Text Available Abstract Background Sulforaphane (SFN, an isothiocyanate phytochemical present predominantly in cruciferous vegetables such as brussels sprout and broccoli, is considered a promising chemo-preventive agent against cancer. In-vitro exposure to SFN appears to result in the induction of apoptosis and cell-cycle arrest in a variety of tumor types. However, the molecular mechanisms leading to the inhibition of cell cycle progression by SFN are poorly understood in epithelial ovarian cancer cells (EOC. The aim of this study is to understand the signaling mechanisms through which SFN influences the cell growth and proliferation in EOC. Results SFN at concentrations of 5 - 20 μM induced a dose-dependent suppression of growth in cell lines MDAH 2774 and SkOV-3 with an IC50 of ~8 μM after a 3 day exposure. Combination treatment with chemotherapeutic agent, paclitaxel, resulted in additive growth suppression. SFN at ~8 μM decreased growth by 40% and 20% on day 1 in MDAH 2774 and SkOV-3, respectively. Cells treated with cytotoxic concentrations of SFN have reduced cell migration and increased apoptotic cell death via an increase in Bak/Bcl-2 ratio and cleavage of procaspase-9 and poly (ADP-ribose-polymerase (PARP. Gene expression profile analysis of cell cycle regulated proteins demonstrated increased levels of tumor suppressor retinoblastoma protein (RB and decreased levels of E2F-1 transcription factor. SFN treatment resulted in G1 cell cycle arrest through down modulation of RB phosphorylation and by protecting the RB-E2F-1 complex. Conclusions SFN induces growth arrest and apoptosis in EOC cells. Inhibition of retinoblastoma (RB phosphorylation and reduction in levels of free E2F-1 appear to play an important role in EOC growth arrest.

  9. Inhibition of protein kinase B activity induces cell cycle arrest and apoptosis during early G₁ phase in CHO cells.

    Science.gov (United States)

    van Opstal, Angélique; Bijvelt, José; van Donselaar, Elly; Humbel, Bruno M; Boonstra, Johannes

    2012-04-01

    Inhibition of PKB (protein kinase B) activity using a highly selective PKB inhibitor resulted in inhibition of cell cycle progression only if cells were in early G1 phase at the time of addition of the inhibitor, as demonstrated by time-lapse cinematography. Addition of the inhibitor during mitosis up to 2 h after mitosis resulted in arrest of the cells in early G1 phase, as deduced from the expression of cyclins D and A and incorporation of thymidine. After 24 h of cell cycle arrest, cells expressed the cleaved caspase-3, a central mediator of apoptosis. These results demonstrate that PKB activity in early G1 phase is required to prevent the induction of apoptosis. Using antibodies, it was demonstrated that active PKB translocates to the nucleus during early G1 phase, while an even distribution of PKB was observed through cytoplasm and nucleus during the end of G1 phase. PMID:22251027

  10. Arrested neural and advanced mesenchymal differentiation of glioblastoma cells-comparative study with neural progenitors

    Directory of Open Access Journals (Sweden)

    Biernat Wojciech

    2009-02-01

    Full Text Available Abstract Background Although features of variable differentiation in glioblastoma cell cultures have been reported, a comparative analysis of differentiation properties of normal neural GFAP positive progenitors, and those shown by glioblastoma cells, has not been performed. Methods Following methods were used to compare glioblastoma cells and GFAP+NNP (NHA: exposure to neural differentiation medium, exposure to adipogenic and osteogenic medium, western blot analysis, immunocytochemistry, single cell assay, BrdU incorporation assay. To characterize glioblastoma cells EGFR amplification analysis, LOH/MSI analysis, and P53 nucleotide sequence analysis were performed. Results In vitro differentiation of cancer cells derived from eight glioblastomas was compared with GFAP-positive normal neural progenitors (GFAP+NNP. Prior to exposure to differentiation medium, both types of cells showed similar multilineage phenotype (CD44+/MAP2+/GFAP+/Vimentin+/Beta III-tubulin+/Fibronectin+ and were positive for SOX-2 and Nestin. In contrast to GFAP+NNP, an efficient differentiation arrest was observed in all cell lines isolated from glioblastomas. Nevertheless, a subpopulation of cells isolated from four glioblastomas differentiated after serum-starvation with varying efficiency into derivatives indistinguishable from the neural derivatives of GFAP+NNP. Moreover, the cells derived from a majority of glioblastomas (7 out of 8, as well as GFAP+NNP, showed features of mesenchymal differentiation when exposed to medium with serum. Conclusion Our results showed that stable co-expression of multilineage markers by glioblastoma cells resulted from differentiation arrest. According to our data up to 95% of glioblastoma cells can present in vitro multilineage phenotype. The mesenchymal differentiation of glioblastoma cells is advanced and similar to mesenchymal differentiation of normal neural progenitors GFAP+NNP.

  11. Exine dehiscing induces rape microspore polarity, which results in different daughter cell fate and fixes the apical–basal axis of the embryo

    Science.gov (United States)

    Tang, Xingchun; Liu, Yuan; Sun, Meng-xiang

    2013-01-01

    The roles of cell polarity and the first asymmetric cell division during early embryogenesis in apical–basal cell fate determination remain unclear. Previously, a novel Brassica napus microspore embryogenesis system was established, by which rape exine-dehisced microspores were induced by physical stress. Unlike traditional microspore culture, cell polarity and subsequent asymmetric division appeared in the exine-dehisced microspore, which finally developed into a typical embryo with a suspensor. Further studies indicated that polarity is critical for apical–basal cell fate determination and suspensor formation. However, the pattern of the first division was not only determined by cell polarity but was also regulated by the position of the ruptured exine. The first division could be equal or unequal, with its orientation essentially perpendicular to the polar axis. In both types of cell division, the two daughter cells could have different cell fates and give rise to an embryo with a suspensor, similar to zygotic apical–basal cell differentiation. The alignment of the two daughter cells is consistent with the orientation of the apical–basal axis of future embryonic development. Thus, the results revealed that exine dehiscing induces rape microspore polarization, and this polarity results in a different cell fate and fixes the apical–basal axis of embryogenesis, but is uncoupled from cell asymmetric division. The present study demonstrated the relationships among cell polarity, asymmetric cell division, and cell fate determination in early embryogenesis. PMID:23162119

  12. Exine dehiscing induces rape microspore polarity, which results in different daughter cell fate and fixes the apical-basal axis of the embryo.

    Science.gov (United States)

    Tang, Xingchun; Liu, Yuan; He, Yuqing; Ma, Ligang; Sun, Meng-Xiang

    2013-01-01

    The roles of cell polarity and the first asymmetric cell division during early embryogenesis in apical-basal cell fate determination remain unclear. Previously, a novel Brassica napus microspore embryogenesis system was established, by which rape exine-dehisced microspores were induced by physical stress. Unlike traditional microspore culture, cell polarity and subsequent asymmetric division appeared in the exine-dehisced microspore, which finally developed into a typical embryo with a suspensor. Further studies indicated that polarity is critical for apical-basal cell fate determination and suspensor formation. However, the pattern of the first division was not only determined by cell polarity but was also regulated by the position of the ruptured exine. The first division could be equal or unequal, with its orientation essentially perpendicular to the polar axis. In both types of cell division, the two daughter cells could have different cell fates and give rise to an embryo with a suspensor, similar to zygotic apical-basal cell differentiation. The alignment of the two daughter cells is consistent with the orientation of the apical-basal axis of future embryonic development. Thus, the results revealed that exine dehiscing induces rape microspore polarization, and this polarity results in a different cell fate and fixes the apical-basal axis of embryogenesis, but is uncoupled from cell asymmetric division. The present study demonstrated the relationships among cell polarity, asymmetric cell division, and cell fate determination in early embryogenesis. PMID:23162119

  13. Differential growth rates of Candida utilis mother and daughter cells under phased cultivation.

    OpenAIRE

    Thomas, K C; Dawson, P S; Gamborg, B L

    1980-01-01

    The yeast Candida utilis was continuously synchronized by the phased method of cultivation with the nitrogen source as the growth-limiting nutrient. The doubling time (phasing period) of cells was 6 h. Both cell number and deoxyribonucleic acid synthesis showed a characteristic stepwise increase during the phased growth. The time of bud emergence coincided with the time of initiation of deoxyribonucleic acid synthesis. Size distribution studies combined with microscopic analysis showed that t...

  14. Perivascular Arrest of CD8+ T Cells Is a Signature of Experimental Cerebral Malaria.

    Directory of Open Access Journals (Sweden)

    Tovah N Shaw

    Full Text Available There is significant evidence that brain-infiltrating CD8+ T cells play a central role in the development of experimental cerebral malaria (ECM during Plasmodium berghei ANKA infection of C57BL/6 mice. However, the mechanisms through which they mediate their pathogenic activity during malaria infection remain poorly understood. Utilizing intravital two-photon microscopy combined with detailed ex vivo flow cytometric analysis, we show that brain-infiltrating T cells accumulate within the perivascular spaces of brains of mice infected with both ECM-inducing (P. berghei ANKA and non-inducing (P. berghei NK65 infections. However, perivascular T cells displayed an arrested behavior specifically during P. berghei ANKA infection, despite the brain-accumulating CD8+ T cells exhibiting comparable activation phenotypes during both infections. We observed T cells forming long-term cognate interactions with CX3CR1-bearing antigen presenting cells within the brains during P. berghei ANKA infection, but abrogation of this interaction by targeted depletion of the APC cells failed to prevent ECM development. Pathogenic CD8+ T cells were found to colocalize with rare apoptotic cells expressing CD31, a marker of endothelial cells, within the brain during ECM. However, cellular apoptosis was a rare event and did not result in loss of cerebral vasculature or correspond with the extensive disruption to its integrity observed during ECM. In summary, our data show that the arrest of T cells in the perivascular compartments of the brain is a unique signature of ECM-inducing malaria infection and implies an important role for this event in the development of the ECM-syndrome.

  15. 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.

  16. Genistein Enhances the Radiosensitivity of Breast Cancer Cells via G2/M Cell Cycle Arrest and Apoptosis

    Directory of Open Access Journals (Sweden)

    Li Gong

    2013-10-01

    Full Text Available The aim of the present study was to investigate the radiosensitizing effect of genistein, and the corresponding mechanisms of action on breast cancer cells with different estrogen receptor (ER status. Human breast cancer cell lines such as MCF-7 (ER-positive, harboring wild-type p53 and MDA-MB-231 (ER-negative, harboring mutant p53 were irradiated with X-rays in the presence or absence of genistein. Cell survival, DNA damage and repair, cell cycle distribution, cell apoptosis, expression of proteins related to G2/M cell cycle checkpoint and apoptosis were measured with colony formation assays, immunohistochemistry, flow cytometry and western blot analysis, respectively. Genistein showed relatively weak toxicity to both cell lines at concentrations in the range of 5–20 μM. Using the dosage of 10 μM genistein, the sensitizer enhancement ratios after exposure to X-rays at a 10% cell survival (IC10 were 1.43 for MCF-7 and 1.36 for MDA-MB-231 cells, respectively. Significantly increased DNA damages, arrested cells at G2/M phase, decreased homologous recombination repair protein Rad51 foci formation and enhanced apoptotic rates were observed in both cell lines treated by genistein combined with X-rays compared with the irradiation alone. The combined treatment obviously up-regulated the phosphorylation of ATM, Chk2, Cdc25c and Cdc2, leading to permanent G2/M phase arrest, and up-regulated Bax and p73, down-regulated Bcl-2, finally induced mitochondria-mediated apoptosis in both cell lines. These results suggest that genistein induces G2/M arrest by the activation of the ATM/Chk2/Cdc25C/Cdc2 checkpoint pathway and ultimately enhances the radiosensitivity of both ER+ and ER- breast cancer cells through a mitochondria-mediated apoptosis pathway.

  17. Alisertib Induces Cell Cycle Arrest, Apoptosis, Autophagy and Suppresses EMT in HT29 and Caco-2 Cells

    Directory of Open Access Journals (Sweden)

    Bao-Jun Ren

    2015-12-01

    Full Text Available Colorectal cancer (CRC is one of the most common malignancies worldwide with substantial mortality and morbidity. Alisertib (ALS is a selective Aurora kinase A (AURKA inhibitor with unclear effect and molecular interactome on CRC. This study aimed to evaluate the molecular interactome and anticancer effect of ALS and explore the underlying mechanisms in HT29 and Caco-2 cells. ALS markedly arrested cells in G2/M phase in both cell lines, accompanied by remarkable alterations in the expression level of key cell cycle regulators. ALS induced apoptosis in HT29 and Caco-2 cells through mitochondrial and death receptor pathways. ALS also induced autophagy in HT29 and Caco-2 cells, with the suppression of phosphoinositide 3-kinase (PI3K/protein kinase B (Akt/mammalian target of rapamycin (mTOR, but activation of 5′ AMP-activated protein kinase (AMPK signaling pathways. There was a differential modulating effect of ALS on p38 MAPK signaling pathway in both cell lines. Moreover, induction or inhibition of autophagy modulated basal and ALS-induced apoptosis in both cell lines. ALS potently suppressed epithelial to mesenchymal transition (EMT in HT29 and Caco-2 cells. Collectively, it suggests that induction of cell cycle arrest, promotion of apoptosis and autophagy, and suppression of EMT involving mitochondrial, death receptor, PI3K/Akt/mTOR, p38 MAPK, and AMPK signaling pathways contribute to the cancer cell killing effect of ALS on CRC cells.

  18. Arecoline decreases interleukin-6 production and induces apoptosis and cell cycle arrest in human basal cell carcinoma cells

    International Nuclear Information System (INIS)

    Arecoline, the most abundant areca alkaloid, has been reported to decrease interleukin-6 (IL-6) levels in epithelial cancer cells. Since IL-6 overexpression contributes to the tumorigenic potency of basal cell carcinoma (BCC), this study was designed to investigate whether arecoline altered IL-6 expression and its downstream regulation of apoptosis and the cell cycle in cultured BCC-1/KMC cells. BCC-1/KMC cells and a human keratinocyte cell line, HaCaT, were treated with arecoline at concentrations ranging from 10 to 100 μg/ml, then IL-6 production and expression of apoptosis- and cell cycle progress-related factors were examined. After 24 h exposure, arecoline inhibited BCC-1/KMC cell growth and decreased IL-6 production in terms of mRNA expression and protein secretion, but had no effect on HaCaT cells. Analysis of DNA fragmentation and chromatin condensation showed that arecoline induced apoptosis of BCC-1/KMC cells in a dose-dependent manner, activated caspase-3, and decreased expression of the anti-apoptotic protein Bcl-2. In addition, arecoline induced progressive and sustained accumulation of BCC-1/KMC cells in G2/M phase as a result of reducing checkpoint Cdc2 activity by decreasing Cdc25C phosphatase levels and increasing p53 levels. Furthermore, subcutaneous injection of arecoline led to decreased BCC-1/KMC tumor growth in BALB/c mice by inducing apoptosis. This study demonstrates that arecoline has potential for preventing BCC tumorigenesis by reducing levels of the tumor cell survival factor IL-6, increasing levels of the tumor suppressor factor p53, and eliciting cell cycle arrest, followed by apoptosis. Highlights: ► Arecoline has potential to prevent against basal cell carcinoma tumorigenesis. ► It has more effectiveness on BCC as compared with a human keratinocyte cell line. ► Mechanisms involved including reducing tumor cells’ survival factor IL-6, ► Decreasing Cdc25C phosphatase, enhancing tumor suppressor factor p53, ► Eliciting G2/M

  19. Arecoline decreases interleukin-6 production and induces apoptosis and cell cycle arrest in human basal cell carcinoma cells

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Li-Wen [Department of Medical Laboratory Science and Biotechnology, Kaohsiung Medical University, Kaohsiung 80708, Taiwan (China); Hsieh, Bau-Shan; Cheng, Hsiao-Ling [Department of Biochemistry, Faculty of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 80708, Taiwan (China); Hu, Yu-Chen [Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 80708, Taiwan (China); Chang, Wen-Tsan [Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 80708, Taiwan (China); Division of Hepatobiliarypancreatic Surgery, Department of Surgery, Kaohsiung Medical University Hospital, Kaohsiung 80708, Taiwan (China); Chang, Kee-Lung, E-mail: Chang.KeeLung@msa.hinet.net [Department of Biochemistry, Faculty of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 80708, Taiwan (China); Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 80708, Taiwan (China)

    2012-01-15

    Arecoline, the most abundant areca alkaloid, has been reported to decrease interleukin-6 (IL-6) levels in epithelial cancer cells. Since IL-6 overexpression contributes to the tumorigenic potency of basal cell carcinoma (BCC), this study was designed to investigate whether arecoline altered IL-6 expression and its downstream regulation of apoptosis and the cell cycle in cultured BCC-1/KMC cells. BCC-1/KMC cells and a human keratinocyte cell line, HaCaT, were treated with arecoline at concentrations ranging from 10 to 100 μg/ml, then IL-6 production and expression of apoptosis- and cell cycle progress-related factors were examined. After 24 h exposure, arecoline inhibited BCC-1/KMC cell growth and decreased IL-6 production in terms of mRNA expression and protein secretion, but had no effect on HaCaT cells. Analysis of DNA fragmentation and chromatin condensation showed that arecoline induced apoptosis of BCC-1/KMC cells in a dose-dependent manner, activated caspase-3, and decreased expression of the anti-apoptotic protein Bcl-2. In addition, arecoline induced progressive and sustained accumulation of BCC-1/KMC cells in G2/M phase as a result of reducing checkpoint Cdc2 activity by decreasing Cdc25C phosphatase levels and increasing p53 levels. Furthermore, subcutaneous injection of arecoline led to decreased BCC-1/KMC tumor growth in BALB/c mice by inducing apoptosis. This study demonstrates that arecoline has potential for preventing BCC tumorigenesis by reducing levels of the tumor cell survival factor IL-6, increasing levels of the tumor suppressor factor p53, and eliciting cell cycle arrest, followed by apoptosis. Highlights: ► Arecoline has potential to prevent against basal cell carcinoma tumorigenesis. ► It has more effectiveness on BCC as compared with a human keratinocyte cell line. ► Mechanisms involved including reducing tumor cells’ survival factor IL-6, ► Decreasing Cdc25C phosphatase, enhancing tumor suppressor factor p53, ► Eliciting G2/M

  20. Epithelial cell proliferation arrest induced by lactate and acetate from Lactobacillus casei and Bifidobacterium breve.

    Directory of Open Access Journals (Sweden)

    Takahiro Matsuki

    Full Text Available In an attempt to identify and characterize how symbiotic bacteria of the gut microbiota affect the molecular and cellular mechanisms of epithelial homeostasis, intestinal epithelial cells were co-cultured with either Lactobacillus or Bifidobacterium as bona fide symbionts to examine potential gene modulations. In addition to genes involved in the innate immune response, genes encoding check-point molecules controlling the cell cycle were among the most modulated in the course of these interactions. In the m-ICcl2 murine cell line, genes encoding cyclin E1 and cyclin D1 were strongly down regulated by L. casei and B. breve respectively. Cell proliferation arrest was accordingly confirmed. Short chain fatty acids (SCFA were the effectors of this modulation, alone or in conjunction with the acidic pH they generated. These results demonstrate that the production of SCFAs, a characteristic of these symbiotic microorganisms, is potentially an essential regulatory effector of epithelial proliferation in the gut.

  1. Respiratory Syncytial Virus Matrix Protein Induces Lung Epithelial Cell Cycle Arrest through a p53 Dependent Pathway

    OpenAIRE

    Bian, Tao; John D Gibbs; Örvell, Claes; Imani, Farhad

    2012-01-01

    Respiratory syncytial virus (RSV) is the major cause of viral respiratory infections in children. Our previous study showed that the RSV infection induced lung epithelial cell cycle arrest, which enhanced virus replication. To address the mechanism of RSV-induced cell cycle arrest, we examined the contribution of RSV-matrix (RSV-M) protein. In this report, we show that in both the A549 cell line and primary human bronchial epithelial (PHBE) cells, transfection with RSV-M protein caused the ce...

  2. Xanthones from the Leaves of Garcinia cowa Induce Cell Cycle Arrest, Apoptosis, and Autophagy in Cancer Cells

    OpenAIRE

    Zhengxiang Xia; Hong Zhang; Danqing Xu; Yuanzhi Lao; Wenwei Fu; Hongsheng Tan; Peng Cao; Ling Yang; Hongxi Xu

    2015-01-01

    Two new xanthones, cowaxanthones G (1) and H (2), and 23 known analogues were isolated from an acetone extract of the leaves of Garcinia cowa. The isolated compounds were evaluated for cytotoxicity against three cancer cell lines and immortalized HL7702 normal liver cells, whereby compounds 1, 5, 8, and 15–17 exhibited significant cytotoxicity. Cell cycle analysis using flow cytometry showed that 5 induced cell cycle arrest at the S phase in a dose-dependent manner, 1 and 16 at the G2/M phase...

  3. Induction of apoptosis and antiproliferative activity of naringenin in human epidermoid carcinoma cell through ROS generation and cell cycle arrest.

    Directory of Open Access Journals (Sweden)

    Md Sultan Ahamad

    Full Text Available A natural predominant flavanone naringenin, especially abundant in citrus fruits, has a wide range of pharmacological activities. The search for antiproliferative agents that reduce skin carcinoma is a task of great importance. The objective of this study was to analyze the anti-proliferative and apoptotic mechanism of naringenin using MTT assay, DNA fragmentation, nuclear condensation, change in mitochondrial membrane potential, cell cycle kinetics and caspase-3 as biomarkers and to investigate the ability to induce reactive oxygen species (ROS initiating apoptotic cascade in human epidermoid carcinoma A431 cells. Results showed that naringenin exposure significantly reduced the cell viability of A431 cells (p<0.01 with a concomitant increase in nuclear condensation and DNA fragmentation in a dose dependent manner. The intracellular ROS generation assay showed statistically significant (p<0.001 dose-related increment in ROS production for naringenin. It also caused naringenin-mediated epidermoid carcinoma apoptosis by inducing mitochondrial depolarization. Cell cycle study showed that naringenin induced cell cycle arrest in G0/G1 phase of cell cycle and caspase-3 analysis revealed a dose dependent increment in caspase-3 activity which led to cell apoptosis. This study confirms the efficacy of naringenin that lead to cell death in epidermoid carcinoma cells via inducing ROS generation, mitochondrial depolarization, nuclear condensation, DNA fragmentation, cell cycle arrest in G0/G1 phase and caspase-3 activation.

  4. Unprecedented inhibition of tubulin polymerization directed by gold nanoparticles inducing cell cycle arrest and apoptosis

    Science.gov (United States)

    Choudhury, Diptiman; Xavier, Paulrajpillai Lourdu; Chaudhari, Kamalesh; John, Robin; Dasgupta, Anjan Kumar; Pradeep, Thalappil; Chakrabarti, Gopal

    2013-05-01

    The effect of gold nanoparticles (AuNPs) on the polymerization of tubulin has not been examined till now. We report that interaction of weakly protected AuNPs with microtubules (MTs) could cause inhibition of polymerization and aggregation in the cell free system. We estimate that single citrate capped AuNPs could cause aggregation of ~105 tubulin heterodimers. Investigation of the nature of inhibition of polymerization and aggregation by Raman and Fourier transform-infrared (FTIR) spectroscopies indicated partial conformational changes of tubulin and microtubules, thus revealing that AuNP-induced conformational change is the driving force behind the observed phenomenon. Cell culture experiments were carried out to check whether this can happen inside a cell. Dark field microscopy (DFM) combined with hyperspectral imaging (HSI) along with flow cytometric (FC) and confocal laser scanning microscopic (CLSM) analyses suggested that AuNPs entered the cell, caused aggregation of the MTs of A549 cells, leading to cell cycle arrest at the G0/G1 phase and concomitant apoptosis. Further, Western blot analysis indicated the upregulation of mitochondrial apoptosis proteins such as Bax and p53, down regulation of Bcl-2 and cleavage of poly(ADP-ribose) polymerase (PARP) confirming mitochondrial apoptosis. Western blot run after cold-depolymerization revealed an increase in the aggregated insoluble intracellular tubulin while the control and actin did not aggregate, suggesting microtubule damage induced cell cycle arrest and apoptosis. The observed polymerization inhibition and cytotoxic effects were dependent on the size and concentration of the AuNPs used and also on the incubation time. As microtubules are important cellular structures and target for anti-cancer drugs, this first observation of nanoparticles-induced protein's conformational change-based aggregation of the tubulin-MT system is of high importance, and would be useful in the understanding of cancer therapeutics

  5. Direct inhibition of Retinoblastoma phosphorylation by Nimbolide causes cell cycle arrest and suppresses glioblastoma growth

    Science.gov (United States)

    Anderson, Jane; Liu, Xiaona; Henry, Heather; Gasilina, Anjelika; Nassar, Nicholas; Ghosh, Jayeeta; Clark, Jason P; Kumar, Ashish; Pauletti, Giovanni M.; Ghosh, Pradip K; Dasgupta, Biplab

    2013-01-01

    Purpose Classical pharmacology allows the use and development of conventional phytomedicine faster and more economically than conventional drugs. This approach should be tested for their efficacy in terms of complementarity and disease control. The purpose of this study was to determine the molecular mechanisms by which nimbolide, a triterpenoid found in the well-known medicinal plant Azadirachta indica controls glioblastoma (GBM) growth. Experimental Design Using in vitro signaling, anchorage-independent growth, kinase assays, and xenograft models, we investigated the mechanisms of its growth inhibition in glioblastoma. Results We show that nimbolide or an ethanol soluble fraction of A. indica leaves (Azt) that contains nimbolide as the principal cytotoxic agent is highly cytotoxic against GBM in vitro and in vivo. Azt caused cell cycle arrest, most prominently at the G1-S stage in GBM cells expressing EGFRvIII, an oncogene present in about 20-25% of GBMs. Azt/nimbolide directly inhibited CDK4/CDK6 kinase activity leading to hypophosphorylation of the retinoblastoma (RB) protein, cell cycle arrest at G1-S and cell death. Independent of RB hypophosphorylation, Azt also significantly reduced proliferative and survival advantage of GBM cells in vitro and in tumor xenografts by downregulating Bcl2 and blocking growth factor induced phosphorylation of Akt, Erk1/2 and STAT3. These effects were specific since Azt did not affect mTOR or other cell cycle regulators. In vivo, Azt completely prevented initiation and inhibited progression of GBM growth. Conclusions Our preclinical findings demonstrate Nimbolide as a potent anti-glioma agent that blocks cell cycle and inhibits glioma growth in vitro and in vivo. PMID:24170547

  6. Polydatin-induced cell apoptosis and cell cycle arrest are potentiated by Janus kinase 2 inhibition in leukemia cells.

    Science.gov (United States)

    Cao, Wei-Jie; Wu, Ke; Wang, Chong; Wan, Ding-Ming

    2016-04-01

    Polydatin (PD), a natural precursor of resveratrol, has a variety of biological activities, including anti‑tumor effects. However, the underlying molecular mechanisms of the anti-cancer activity of PD has not been fully elucidated. The present study demonstrated that PD significantly inhibited the proliferation of the MOLT-4 leukemia cell line in a dose‑ and time-dependent manner by using Cell Counting Kit‑8 assay. PD also dose-dependently increased the apoptotic rate and caused cell cycle arrest in S phase in MOLT‑4 cells, as revealed by flow cytometry. In addition, PD dose-dependently decreased the mitochondrial membrane potential and led to the generation of reactive oxygen species in MOLT-4 cells. Western blot analysis revealed that the expression of anti‑apoptotic protein B-cell lymphoma 2 (Bcl-2) was decreased, whereas that of pro‑apoptotic protein Bcl‑2‑associated X was increased by PD. Furthermore, the expression of two cell cycle regulatory proteins, cyclin D1 and cyclin B1, was suppressed by PD. Of note, the pro‑apoptotic and cell cycle‑inhibitory effects of PD were potentiated by Janus kinase 2 (JAK2) inhibition. In conclusion, the results of the present study strongly suggested that PD is a promising therapeutic compound for the treatment of leukemia, particularly in combination with JAK inhibitors. PMID:26934953

  7. Pravastatin induces cell cycle arrest and decreased production of VEGF and bFGF in multiple myeloma cell line.

    Science.gov (United States)

    Trojan, P J J; Bohatch-Junior, M S; Otuki, M F; Souza-Fonseca-Guimarães, F; Svidnicki, P V; Nogaroto, V; Fernandes, D; Krum, E A; Favero, G M

    2016-02-01

    Multiple myeloma (MM) is a B cell bone marrow neoplasia characterized by inflammation with an intense secretion of growth factors that promote tumor growth, cell survival, migration and invasion. The aim of this study was to evaluate the effects of pravastatin, a drug used to reduce cholesterol, in a MM cell line.Cell cycle and viability were determinate by Trypan Blue and Propidium Iodide. IL6, VEGF, bFGF and TGFβ were quantified by ELISA and qRT-PCR including here de HMG CoA reductase. It was observed reduction of cell viability, increase of cells in G0/G1 phase of the cell cycle and reducing the factors VEGF and bFGF without influence on 3-Methyl-Glutaryl Coenzyme A reductase expression.The results demonstrated that pravastatin induces cell cycle arrest in G0/G1 and decreased production of growth factors in Multiple Myeloma cell line. PMID:26909624

  8. Parafibromin inhibits cancer cell growth and causes G1 phase arrest

    International Nuclear Information System (INIS)

    The HRPT2 (hereditary hyperparathyroidism type 2) tumor suppressor gene encodes a ubiquitously expressed 531 amino acid protein termed parafibromin. Inactivation of parafibromin predisposes one to the development of HPT-JT syndrome. To date, the role of parafibromin in tumorigenesis is largely unknown. Here, we report that parafibromin is a nuclear protein that possesses anti-proliferative properties. We show that overexpression of parafibromin inhibits colony formation and cellular proliferation, and induces cell cycle arrest in the G1 phase. Moreover, HPT-JT syndrome-derived mutations in HRPT2 behave in a dominant-negative manner by abolishing the ability of parafibromin to suppress cell proliferation. These findings suggest that parafibromin has a critical role in cell growth, and mutations in HRPT2 can directly inhibit this role

  9. Honokiol, a chemopreventive agent against skin cancer, induces cell cycle arrest and apoptosis in human epidermoid A431 cells.

    Science.gov (United States)

    Chilampalli, Chandeshwari; Guillermo, Ruth; Kaushik, Radhey S; Young, Alan; Chandrasekher, Gudiseva; Fahmy, Hesham; Dwivedi, Chandradhar

    2011-11-01

    Honokiol is a plant lignan isolated from bark and seed cones of Magnolia officinalis. Recent studies from our laboratory indicated that honokiol pretreatment decreased ultraviolet B-induced skin cancer development in SKH-1 mice. The aim of the present investigation was to study the effects of honokiol on human epidermoid squamous carcinoma A431 cells and to elucidate possible mechanisms involved in preventing skin cancer. A431 cells were pretreated with different concentrations of honokiol for a specific time period and investigated for effects on apoptosis and cell cycle analysis. Treatment with honokiol significantly decreased cell viability and cell proliferation in a concentration- and time-dependent manner. Honokiol pretreatment at 50 μmol/L concentration induced G0/G1 cell cycle arrest significantly (P Cdk4 and Cdk6 proteins and up-regulated the expression of Cdk's inhibitor proteins p21 and p27. Pretreatment of A431 cells with honokiol leads to induction of apoptosis and DNA fragmentation. These findings indicate that honokiol provides its effects in squamous carcinoma cells by inducing cell cycle arrest at G0/G1 phase and apoptosis. PMID:21908486

  10. Synadenium umbellatum Pax. promotes cell cycle arrest and induces apoptosis in K-562 leukemia cells

    Directory of Open Access Journals (Sweden)

    Mariana Flavia da Mota

    2012-09-01

    Full Text Available Chronic myeloid leukemia (CML is a clonal myeloproliferative disease that shows apoptosis resistance. The introduction of imatinib mesylate has revolutionized the treatment of CML, but imatinib resistance may develop at any time and inevitably leads to disease progression. Synadenium umbellatum Pax. belongs to the Euphorbiaceae family and is popularly used in Brazil for the treatment of cancer. The cytotoxicity of Euphorbiaceae is associated with the ability of these plants and their bioactive compounds to induce apoptotic tumor cell death. Therefore, we aimed to investigate the cytotoxicity and the mechanisms of death induced by S. umbellatum extract in leukemic cells. S. umbellatum cytotoxicity was evaluated by trypan blue exclusion assay and flow cytometric analysis of the cell cycle; the mechanisms involved in K-562 cell death were investigated by light microscopy and flow cytometry. The results demonstrate that S. umbellatum is cytotoxic to leukemic cells in a concentration-dependent manner. Morphological analysis revealed that S. umbellatum treatment induced K-562 cell death by an apoptotic pathway. Furthermore, data indicate ROS overproduction, alterations in mitochondrial membrane potential, phosphatidylserine externalization and activation of caspase 9. Taken together, the results demonstrate that S. umbellatum extract arrested the cell cycle and triggered apoptosis at several levels in K-562 cells.A leucemia mielóide crônica (LMC é uma doença mieloproliferativa clonal, que apresenta resistência à apoptose. A introdução do mesilato de imatinibe revolucionou o tratamento da LMC, porém a resistência ao imatinibe pode ser desenvolvida em qualquer tempo e, inevitavelmente, leva à progressão da doença. Synadenium umbellatum Pax. pertence à família Euphorbiaceae e é usado popularmente no Brasil para o tratamento do câncer. A citotoxicidade das Euphorbiaceae está associada com a capacidade dessas plantas e seus compostos

  11. Mechanisms of G1 cell cycle arrest and apoptosis in myeloma cells induced by hybrid-compound histone deacetylase inhibitor

    Energy Technology Data Exchange (ETDEWEB)

    Fujii, Seiko [Division of Infections and Molecular Biology, Kyushu Dental University (Japan); Division of Maxillofacial Surgery, Kyushu Dental University (Japan); Okinaga, Toshinori; Ariyoshi, Wataru [Division of Infections and Molecular Biology, Kyushu Dental University (Japan); Oral Biology Research Center, Kyushu Dental University (Japan); Takahashi, Osamu; Iwanaga, Kenjiro [Division of Maxillofacial Surgery, Kyushu Dental University (Japan); Nishino, Norikazu [Oral Biology Research Center, Kyushu Dental University (Japan); Tominaga, Kazuhiro [Division of Maxillofacial Surgery, Kyushu Dental University (Japan); Nishihara, Tatsuji, E-mail: tatsujin@kyu-dent.ac.jp [Division of Infections and Molecular Biology, Kyushu Dental University (Japan); Oral Biology Research Center, Kyushu Dental University (Japan)

    2013-05-10

    Highlights: •Novel histone deacetylase inhibitor Ky-2, remarkably inhibits myeloma cell growth. •Ky-2 demonstrates no cytotoxicity against normal lymphocytic cells. •Ky-2 induces cell cycle arrest through the cell cycle-associated proteins. •Ky-2 induces Bcl-2-inhibitable apoptosis through a caspase-dependent cascade. -- Abstract: Objectives: Histone deacetylase (HDAC) inhibitors are new therapeutic agents, used to treat various types of malignant cancers. In the present study, we investigated the effects of Ky-2, a hybrid-compound HDAC inhibitor, on the growth of mouse myeloma cells. Materials and methods: Myeloma cells, HS-72, P3U1, and mouse normal cells were used in this study. Effect of HDAC inhibitors on cell viability was determined by WST-assay and trypan blue assay. Cell cycle was analyzed using flow cytometer. The expression of cell cycle regulatory and the apoptosis associated proteins were examined by Western blot analysis. Hoechst’s staining was used to detect apoptotic cells. Results: Our findings showed that Ky-2 decreased the levels of HDACs, while it enhanced acetylation of histone H3. Myeloma cell proliferation was inhibited by Ky-2 treatment. Interestingly, Ky-2 had no cytotoxic effects on mouse normal cells. Ky-2 treatment induced G1-phase cell cycle arrest and accumulation of a sub-G1 phase population, while Western blotting analysis revealed that expressions of the cell cycle-associated proteins were up-regulated. Also, Ky-2 enhanced the cleavage of caspase-9 and -3 in myeloma cells, followed by DNA fragmentation. In addition, Ky-2 was not found to induce apoptosis in bcl-2 overexpressing myeloma cells. Conclusion: These findings suggest that Ky-2 induces apoptosis via a caspase-dependent cascade and Bcl-2-inhibitable mechanism in myeloma cells.

  12. Mechanisms of G1 cell cycle arrest and apoptosis in myeloma cells induced by hybrid-compound histone deacetylase inhibitor

    International Nuclear Information System (INIS)

    Highlights: •Novel histone deacetylase inhibitor Ky-2, remarkably inhibits myeloma cell growth. •Ky-2 demonstrates no cytotoxicity against normal lymphocytic cells. •Ky-2 induces cell cycle arrest through the cell cycle-associated proteins. •Ky-2 induces Bcl-2-inhibitable apoptosis through a caspase-dependent cascade. -- Abstract: Objectives: Histone deacetylase (HDAC) inhibitors are new therapeutic agents, used to treat various types of malignant cancers. In the present study, we investigated the effects of Ky-2, a hybrid-compound HDAC inhibitor, on the growth of mouse myeloma cells. Materials and methods: Myeloma cells, HS-72, P3U1, and mouse normal cells were used in this study. Effect of HDAC inhibitors on cell viability was determined by WST-assay and trypan blue assay. Cell cycle was analyzed using flow cytometer. The expression of cell cycle regulatory and the apoptosis associated proteins were examined by Western blot analysis. Hoechst’s staining was used to detect apoptotic cells. Results: Our findings showed that Ky-2 decreased the levels of HDACs, while it enhanced acetylation of histone H3. Myeloma cell proliferation was inhibited by Ky-2 treatment. Interestingly, Ky-2 had no cytotoxic effects on mouse normal cells. Ky-2 treatment induced G1-phase cell cycle arrest and accumulation of a sub-G1 phase population, while Western blotting analysis revealed that expressions of the cell cycle-associated proteins were up-regulated. Also, Ky-2 enhanced the cleavage of caspase-9 and -3 in myeloma cells, followed by DNA fragmentation. In addition, Ky-2 was not found to induce apoptosis in bcl-2 overexpressing myeloma cells. Conclusion: These findings suggest that Ky-2 induces apoptosis via a caspase-dependent cascade and Bcl-2-inhibitable mechanism in myeloma cells

  13. Activation of cell cycle arrest and apoptosis by the proto-oncogene Pim-2.

    Directory of Open Access Journals (Sweden)

    Daphna Levy

    Full Text Available Potent survival effects have been ascribed to the serine/threonine kinase proto-oncogene PIM-2. Elevated levels of PIM-2 are associated with various malignancies. In human cells, a single Pim-2 transcript gives rise mainly to two protein isoforms (34, 41 kDa that share an identical catalytic site but differ at their N-terminus, due to in-frame alternative translation initiation sites. In this study we observed that the 34 kDa PIM-2 isoform has differential nuclear and cytoplasmic forms in all tested cell lines, suggesting a possible role for the balance between these forms for PIM-2's function. To further study the cellular role of the 34 kDa isoform of PIM-2, an N-terminally HA-tagged form of this isoform was transiently expressed in HeLa cells. Surprisingly, this resulted in increased level of G1 arrested cells, as well as of apoptotic cells. These effects could not be obtained by a Flag-tagged form of the 41 kDa isoform. The G1 arrest and apoptotic effects were associated with an increase in T14/Y15 phosphorylation of CDK2 and proteasom-dependent down-regulation of CDC25A, as well as with up-regulation of p57, E2F-1, and p73. No such effects were obtained upon over-expression of a kinase-dead form of the HA-tagged 34 kDa PIM-2. By either using a dominant negative form of p73, or by over-expressing the 34 kDa PIM-2 in p73-silenced cells, we demonstrated that these effects were p73-dependent. These results demonstrate that while PIM-2 can function as a potent survival factor, it can, under certain circumstances, exhibit pro-apoptotic effects as well.

  14. Molecular interplay between cdk4 and p21 dictates G0/G1 cell cycle arrest in prostate cancer cells

    OpenAIRE

    Gulappa, Thippeswamy; Reddy, Ramadevi Subramani; Suman, Suman; Nyakeriga, Alice M; Damodaran, Chendil

    2013-01-01

    This study examined the effect of 3, 9-dihydroxy-2-prenylcoumestan (pso), a furanocoumarin, on PC-3 and C4-2B castration-resistant prostate cancer (CRPC) cell lines. Pso caused significant G0/G1 cell cycle arrest and inhibition of cell growth. Molecular analysis of cyclin (D1, D2, D3, and E), cyclin-dependent kinase (cdk) (cdks 2, 4, and 6), and cdk inhibitor (p21 and p27) expression suggested transcriptional regulation of the cdk inhibitors and more significant downregulation of cdk4 than of...

  15. Genistein abrogates G2 arrest induced by curcumin in p53 deficient T47D cells

    Science.gov (United States)

    2012-01-01

    Background The high cost and low level of cancer survival urge the finding of new drugs having better mechanisms. There is a high trend of patients to be “back to nature” and use natural products as an alternative way to cure cancer. The fact is that some of available anticancer drugs are originated from plants, such as taxane, vincristine, vinblastine, pacitaxel. Curcumin (diferuloylmethane), a dietary pigment present in Curcuma longa rizhome is reported to induce cell cycle arrest in some cell lines. Other study reported that genistein isolated from Glycine max seed inhibited phosphorylation of cdk1, gene involved during G2/M transition and thus could function as G2 checkpoint abrogator. The inhibition of cdk1 phosphorylation is one of alternative strategy which could selectively kill cancer cells and potentially be combined with DNA damaging agent such as curcumin. Methods T47D cell line was treated with different concentrations of curcumin and genistein, alone or in combination; added together or with interval time. Flow Cytometry and MTT assay were used to evaluate cell cycle distribution and viability, respectively. The presence of apoptotic cells was determined using acridine orange-ethidium bromide staining. Results In this study curcumin induced G2 arrest on p53 deficient T47D cells at the concentration of 10 μM. Increasing concentration up to 30 μM increased the number of cell death. Whilst genistein alone at low concentration (≤10 μM) induced cell proliferation, addition of genistein (20 μM) 16 h after curcumin resulted in more cell death (89%), 34% higher than that administered at the same time (56%). The combination treatment resulted in apoptotic cell death. Combining curcumin with high dose of genistein (50 μM) induced necrotic cells. Conclusions Genistein increased the death of curcumin treated T47D cells. Appropriate timing of administration and concentration of genistein determine the outcome of treatment and this method

  16. Pfaffosidic Fraction from Hebanthe paniculata Induces Cell Cycle Arrest and Caspase-3-Induced Apoptosis in HepG2 Cells

    Directory of Open Access Journals (Sweden)

    Tereza Cristina da Silva

    2015-01-01

    Full Text Available Hebanthe paniculata roots (formerly Pfaffia paniculata and popularly known as Brazilian ginseng show antineoplastic, chemopreventive, and antiproliferative properties. Functional properties of these roots and their extracts are usually attributed to the pfaffosidic fraction, which is composed mainly by pfaffosides A–F. However, the therapeutic potential of this fraction in cancer cells is not yet entirely understood. This study aimed to analyze the antitumoral effects of the purified pfaffosidic fraction or saponinic fraction on the human hepatocellular carcinoma HepG2 cell line. Cellular viability, proliferation, and apoptosis were evaluated, respectively, by MTT assay, BrdU incorporation, activated caspase-3 immunocytochemistry, and DNA fragmentation assay. Cell cycle was analyzed by flow cytometry and the cell cycle-related proteins were analyzed by quantitative PCR and Western blot. The cells exposed to pfaffosidic fraction had reduced viability and cellular growth, induced G2/M at 48 h or S at 72 h arrest, and increased sub-G1 cell population via cyclin E downregulation, p27KIP1 overexpression, and caspase-3-induced apoptosis, without affecting the DNA integrity. Antitumoral effects of pfaffosidic fraction from H. paniculata in HepG2 cells originated by multimechanisms of action might be associated with cell cycle arrest in the S phase, by CDK2 and cyclin E downregulation and p27KIP1 overexpression, besides induction of apoptosis through caspase-3 activation.

  17. Analysis of HIV-1 Vpr determinants responsible for cell growth arrest in Saccharomyces cerevisiae

    Directory of Open Access Journals (Sweden)

    Yao Xiao-Jian

    2004-08-01

    Full Text Available Abstract Background The HIV-1 genome encodes a well-conserved accessory gene product, Vpr, that serves multiple functions in the retroviral life cycle, including the enhancement of viral replication in nondividing macrophages, the induction of G2 cell-cycle arrest, and the modulation of HIV-1-induced apoptosis. We previously reported the genetic selection of a panel of di-tryptophan (W-containing peptides capable of interacting with HIV-1 Vpr and inhibiting its cytostatic activity in Saccharomyces cerevisiae (Yao, X.-J., J. Lemay, N. Rougeau, M. Clément, S. Kurtz, P. Belhumeur, and E. A. Cohen, J. Biol. Chem. v. 277, p. 48816–48826, 2002. In this study, we performed a mutagenic analysis of Vpr to identify sequence and/or structural determinants implicated in the interaction with di-W-containing peptides and assessed the effect of mutations on Vpr-induced cytostatic activity in S. cerevisiae. Results Our data clearly shows that integrity of N-terminal α-helix I (17–33 and α-helix III (53–83 is crucial for Vpr interaction with di-W-containing peptides as well as for the protein-induced cytostatic effect in budding yeast. Interestingly, several Vpr mutants, mainly in the N- and C-terminal domains, which were previously reported to be defective for cell-cycle arrest or apoptosis in human cells, still displayed a cytostatic activity in S. cerevisiae and remained sensitive to the inhibitory effect of di-W-containing peptides. Conclusions Vpr-induced growth arrest in budding yeast can be effectively inhibited by GST-fused di-W peptide through a specific interaction of di-W peptide with Vpr functional domain, which includes α-helix I (17–33 and α-helix III (53–83. Furthermore, the mechanism(s underlying Vpr-induced cytostatic effect in budding yeast are likely to be distinct from those implicated in cell-cycle alteration and apoptosis in human cells.

  18. Phthalocyanine-mediated photodynamic therapy induces cell death and a G /G1 cell cycle arrest in cervical cancer cells

    International Nuclear Information System (INIS)

    We have developed a series of novel photosensitizers which have potential for anticancer photodynamic therapy (PDT). Photosensitizers include zinc phthalocyanine tetra-sulphonic acid and a family of derivatives with amino acid substituents of varying alkyl chain length and degree of branching. Subcellular localization of these photosensitizers at the phototoxic IC5 concentration in human cervical carcinoma cells (SiHa Cells) was similar to that of the lysosomal dye Lucifer Yellow. Subsequent nuclear relocalization was observed following irradiation with 665 nm laser light. The PDT response was characterized using the Sulforhodamine B cytotoxicity assay. Flow cytometry was used for both DNA cell cycle and dual Annexin V-FITC/propidium iodide analysis. Phototoxicity of the derivatives was of the same order of magnitude as for tetrasulphonated phthalocyanine but with an overall trend of increased phototoxicity with increasing amino acid chain length. Our results demonstrate cell death, inhibition of cell growth, and G /G1 cell cycle arrest during the phthalocyanine PDT-mediated response

  19. Znhit1 causes cell cycle arrest and down-regulates CDK6 expression

    International Nuclear Information System (INIS)

    Cyclin-dependent kinase 6 (CDK6) is the key element of the D-type cyclin holoenzymes which has been found to function in the regulation of G1-phase of the cell cycle and is presumed to play important roles in T cell function. In this study, Znhit1, a member of a new zinc finger protein family defined by a conserved Zf-HIT domain, induced arrest in the G1-phase of the cell cycle in NIH/3T3 cells. Of the G1 cell cycle factors examined, the expression of CDK6 was found to be strongly down-regulated by Znhit1 via transcriptional repression. This effect may have correlations with the decreased acetylation level of histone H4 in the CDK6 promoter region. In addition, considering that CDK6 expression predominates in T cells, the negative regulatory role of Znhit1 in TCR-induced T cell proliferation was validated using transgenic mice. These findings identified Znhit1 as a CDK6 regulator that plays an important role in cell proliferation.

  20. Radical intermediate generation and cell cycle arrest by an aqueous extract of Thunbergia Laurifolia Linn. In human breast cancer cells.

    Science.gov (United States)

    Jetawattana, Suwimol; Boonsirichai, Kanokporn; Charoen, Savapong; Martin, Sean M

    2015-01-01

    Thunbergia Laurifolia Linn. (TL) is one of the most familiar plants in Thai traditional medicine that is used to treat various conditions, including cancer. However, the antitumor activity of TL or its constituents has never been reported at the molecular level to support the folklore claim. The present study was designed to investigate the antitumor effect of an aqueous extract of TL in human breast cancer cells and the possible mechanism(s) of action. An aqueous crude extract was prepared from dried leaves of TL. Folin-Ciocalteu colorimetric assays were used to determine the total phenolic content. Antiproliferative and cell cycle effects were evaluated in human breast adenocarcinoma MCF-7 cells by MTT reduction assay, cell growth inhibition, clonogenic cell survival, and flow cytometric analysis. Free radical generation by the extracts was detected using electron paramagnetic resonance spectroscopy. The exposure of human breast adenocarcinoma MCF-7 cells to a TL aqueous extract resulted in decreases in cell growth, clonogenic cell survival, and cell viability in a concentration-dependent manner with an IC50 value of 843 μg/ml. Treatments with extract for 24 h at 250 μg/ml or higher induced cell cycle arrest as indicated by a significant increase of cell population in the G1 phase and a significant decrease in the S phase of the cell cycle. The capability of the aqueous extract to generate radical intermediates was observed at both high pH and near-neutral pH conditions. The findings suggest the antitumor bioactivities of TL against selected breast cancer cells may be due to induction of a G1 cell cycle arrest. Cytotoxicity and cell cycle perturbation that are associated with a high concentration of the extract could be in part explained by the total phenolic contents in the extract and the capacity to generate radical intermediates to modulate cellular proliferative signals. PMID:26028099

  1. Proteomic analysis of arginine methylation sites in human cells reveals dynamic regulation during transcriptional arrest

    DEFF Research Database (Denmark)

    Sylvestersen, Kathrine B; Horn, Heiko; Jungmichel, Stephanie;

    2014-01-01

    contain regulated functions on their own. Collectively, we present a site-specific MMA dataset in human cells and demonstrate for the first time that MMA is a dynamic post-translational modification regulated during transcriptional arrest by a hitherto uncharacterized arginine demethylase....... mono-methylation (MMA) sites. We thereby identify 1,027 site-specific MMA sites on 494 human proteins, discovering numerous novel mono-methylation targets and confirming the majority of currently known MMA substrates. Nuclear RNA-binding proteins involved in RNA processing, RNA localization......, transcription, and chromatin remodeling are predominantly found modified with MMA. Despite this, MMA sites prominently are located outside RNA-binding domains as compared to the proteome-wide distribution of arginine residues. Quantification of arginine methylation in cells treated with Actinomycin D uncovers...

  2. Asparanin A induces G(2)/M cell cycle arrest and apoptosis in human hepatocellular carcinoma HepG2 cells.

    Science.gov (United States)

    Liu, Wei; Huang, Xue-Feng; Qi, Qi; Dai, Qin-Sheng; Yang, Li; Nie, Fei-Fei; Lu, Na; Gong, Dan-Dan; Kong, Ling-Yi; Guo, Qing-Long

    2009-04-17

    We recently established that asparanin A, a steroidal saponin extracted from Asparagus officinalis L., is an active cytotoxic component. The molecular mechanisms by which asparanin A exerts its cytotoxic activity are currently unknown. In this study, we show that asparanin A induces G(2)/M phase arrest and apoptosis in human hepatocellular carcinoma HepG2 cells. Following treatment of HepG2 cells with asparanin A, cell cycle-related proteins such as cyclin A, Cdk1 and Cdk4 were down-regulated, while p21(WAF1/Cip1) and p-Cdk1 (Thr14/Tyr15) were up-regulated. Additionally, we observed poly (ADP-ribose) polymerase (PARP) cleavage and activation of caspase-3, caspase-8 and caspase-9. The expression ratio of Bax/Bcl-2 was increased in the treated cells, where Bax was also up-regulated. We also found that the expression of p53, a modulator of p21(WAF1/Cip1) and Bax, was not affected in asparanin A-treated cells. Collectively, our findings demonstrate that asparanin A induces cell cycle arrest and triggers apoptosis via a p53-independent manner in HepG2 cells. These data indicate that asparanin A shows promise as a preventive and/or therapeutic agent against human hepatoma. PMID:19254688

  3. Low Doses of Cisplatin Induce Gene Alterations, Cell Cycle Arrest, and Apoptosis in Human Promyelocytic Leukemia Cells.

    Science.gov (United States)

    Velma, Venkatramreddy; Dasari, Shaloam R; Tchounwou, Paul B

    2016-01-01

    Cisplatin is a known antitumor drug, but its mechanisms of action are not fully elucidated. In this research, we studied the anticancer potential of cisplatin at doses of 1, 2, or 3 µM using HL-60 cells as a test model. We investigated cisplatin effects at the molecular level using RNA sequencing, cell cycle analysis, and apoptotic assay after 24, 48, 72, and 96 hours of treatment. The results show that many genes responsible for molecular and cellular functions were significantly altered. Cisplatin treatment also caused the cells to be arrested at the DNA synthesis phase, and as the time increases, the cells gradually accumulated at the sub-G1 phase. Also, as the dose increases, a significant number of cells entered into the apoptotic and necrotic stages. Altogether, the data show that low doses of cisplatin significantly impact the viability of HL-60 cells, through modulation of gene expression, cell cycle, and apoptosis. PMID:27594783

  4. Lidamycin induces marked G2 cell cycle arrest in human colon carcinoma HT-29 cells through activation of p38 MAPK pathway.

    Science.gov (United States)

    Liu, Xia; Bian, Chunjing; Ren, Kaihuan; Jin, Haixia; Li, Baowei; Shao, Rong-Guang

    2007-03-01

    Lidamycin (LDM), a member of the enediyne antibiotic family, is presently undergoing phase I clinical trials in P.R. China. In this study, we investigated the mechanisms of LDM-induced cell cycle arrest in order to support its use in clinical cancer therapy. Using human colon carcinoma HT-29 cells, we observed that LDM induced G2 cell cycle arrest in a time- and dose-dependent manner. LDM-induced G2 arrest was associated with increasing phosphorylation of Chk1, Chk2, Cdc25C, Cdc2 and expression of Cdc2 and cyclin B1. In addition, cytoplasmic localization of cyclin B1 was also involved in LDM-induced G2 arrest. Moreover, we found that p38 MAPK pathway contributed to LDM-induced G2 arrest. Inhibition of p38 MAPK by its inhibitor SB203580 not only attenuated LDM-induced G2 arrest but also potentiated LDM-induced apoptosis, which was accompanied by decreasing phosphorylation of Cdc2 and increasing expression of FasL and phosphorylation of JNK. Finally, we demonstrated that cells at G1 phase were more sensitive to LDM. Together, our findings suggest that p38 MAPK signaling pathway is involved in LDM-induced G2 arrest, at least partly, and a combination of LDM with p38 MAPK inhibitor may represent a new strategy for human colon cancer therapy. PMID:17273739

  5. PTEN enhances G2/M arrest in etoposide-treated MCF‑7 cells through activation of the ATM pathway.

    Science.gov (United States)

    Zhang, Ruopeng; Zhu, Li; Zhang, Lirong; Xu, Anli; Li, Zhengwei; Xu, Yijuan; He, Pei; Wu, Maoqing; Wei, Fengxiang; Wang, Chenhong

    2016-05-01

    As an effective tumor suppressor, phosphatase and tensin homolog (PTEN) has attracted the increased attention of scientists. Recent studies have shown that PTEN plays unique roles in the DNA damage response (DDR) and can interact with the Chk1 pathway. However, little is known about how PTEN contributes to DDR through the ATM-Chk2 pathway. It is well-known that etoposide induces G2/M arrest in a variety of cell lines, including MCF-7 cells. The DNA damage-induced G2/M arrest results from the activation of protein kinase ataxia telangiectasia mutated (ATM), followed by the activation of Chk2 that subsequently inactivates CDC25C, resulting in G2/M arrest. In the present study, we assessed the contribution of PTEN to the etoposide-induced G2/M cell cycle arrest. PTEN was knocked down in MCF-7 cells by specific shRNA, and the effects of PTEN on the ATM-Chk2 pathway were investigated through various approaches. The results showed that knockdown of PTEN strongly antagonized ATM activation in response to etoposide treatment, and thereby reduced the phosphorylation level of ATM substrates, including H2AX, P53 and Chk2. Furthermore, depletion of PTEN reduced the etoposide-induced phosphorylation of CDC25C and strikingly compromised etoposide-induced G2/M arrest in the MCF-7 cells. Altogether, we demonstrated that PTEN plays a unique role in etoposide-induced G2/M arrest by facilitating the activation of the ATM pathway, and PTEN was required for the proper activation of checkpoints in response to DNA damage in MCF-7 cells. PMID:26986476

  6. Unattached kinetochores rather than intrakinetochore tension arrest mitosis in taxol-treated cells.

    Science.gov (United States)

    Magidson, Valentin; He, Jie; Ault, Jeffrey G; O'Connell, Christopher B; Yang, Nachen; Tikhonenko, Irina; McEwen, Bruce F; Sui, Haixin; Khodjakov, Alexey

    2016-02-01

    Kinetochores attach chromosomes to the spindle microtubules and signal the spindle assembly checkpoint to delay mitotic exit until all chromosomes are attached. Light microscopy approaches aimed to indirectly determine distances between various proteins within the kinetochore (termed Delta) suggest that kinetochores become stretched by spindle forces and compact elastically when the force is suppressed. Low Delta is believed to arrest mitotic progression in taxol-treated cells. However, the structural basis of Delta remains unknown. By integrating same-kinetochore light microscopy and electron microscopy, we demonstrate that the value of Delta is affected by the variability in the shape and size of outer kinetochore domains. The outer kinetochore compacts when spindle forces are maximal during metaphase. When the forces are weakened by taxol treatment, the outer kinetochore expands radially and some kinetochores completely lose microtubule attachment, a condition known to arrest mitotic progression. These observations offer an alternative interpretation of intrakinetochore tension and question whether Delta plays a direct role in the control of mitotic progression. PMID:26833787

  7. Unattached kinetochores rather than intrakinetochore tension arrest mitosis in taxol-treated cells

    Science.gov (United States)

    Magidson, Valentin; He, Jie; Ault, Jeffrey G.; O’Connell, Christopher B.; Yang, Nachen; Tikhonenko, Irina; McEwen, Bruce F.

    2016-01-01

    Kinetochores attach chromosomes to the spindle microtubules and signal the spindle assembly checkpoint to delay mitotic exit until all chromosomes are attached. Light microscopy approaches aimed to indirectly determine distances between various proteins within the kinetochore (termed Delta) suggest that kinetochores become stretched by spindle forces and compact elastically when the force is suppressed. Low Delta is believed to arrest mitotic progression in taxol-treated cells. However, the structural basis of Delta remains unknown. By integrating same-kinetochore light microscopy and electron microscopy, we demonstrate that the value of Delta is affected by the variability in the shape and size of outer kinetochore domains. The outer kinetochore compacts when spindle forces are maximal during metaphase. When the forces are weakened by taxol treatment, the outer kinetochore expands radially and some kinetochores completely lose microtubule attachment, a condition known to arrest mitotic progression. These observations offer an alternative interpretation of intrakinetochore tension and question whether Delta plays a direct role in the control of mitotic progression. PMID:26833787

  8. Overexpression of cyclin L2 induces apoptosis and cell-cycle arrest in human lung cancer cells

    Institute of Scientific and Technical Information of China (English)

    LI Hong-li; WANG Tong-shan; LI Xiao-yu; LI Nan; HUANG Ding-zhi; CHEN Qi; BA Yi

    2007-01-01

    Background Uncontrolled cell division is one of the hallmarks of tumor growth. Researches have been focused on numerous molecules involved in this process. Cyclins are critical regulatory proteins of cell cycle progression and/or transcription. The present study aimed to investigate the anti-proliferative effect of cyclin L2, and to define its growth regulatory mechanisms using human lung adenocarcinoma cell line A549.Methods Human cyclin L2 was transfected into human lung adenocarcinoma cells (A549 cell), and was expressed in a mammalian expression vector pcDNA3.1. The effects and mechanisms of the cyclin L2 in cell growth, cell cycle analysis and apoptosis were studied by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), flow cytometry or Western blot, respectively.Results Overexpression of cyclin L2 inhibited the growth of A549 cells. Cell cycle analysis in cells transfected with pCCNL2 revealed an increment in proportion in G0/G1 phase ((68.07 ± 4.2)%) in contrast to (60.39 ± 2.82)% of the cells transfected with mock vector. Apoptosis occurred in (7.25 ± 0.98)% cells transfected with pCCNL2, as compared with (1.25 ± 0.21)% of the mock vector control group. Cyclin L2-induced-G0/G1 arrest and apoptosis involved upregulation of caspase-3 and downregulation of Bcl-2 and survivin.Conclusion The results indicate that overexpression of cyclin L2 protein may promote efficient growth inhibition of human lung adenocarcinoma cells by inducing G0/G1 cell cycle arrest and apoptosis.

  9. Inactivation of nucleolin leads to nucleolar disruption, cell cycle arrest and defects in centrosome duplication

    Directory of Open Access Journals (Sweden)

    Thiry Marc

    2007-08-01

    Full Text Available Abstract Background Nucleolin is a major component of the nucleolus, but is also found in other cell compartments. This protein is involved in various aspects of ribosome biogenesis from transcription regulation to the assembly of pre-ribosomal particles; however, many reports suggest that it could also play an important role in non nucleolar functions. To explore nucleolin function in cell proliferation and cell cycle regulation we used siRNA to down regulate the expression of nucleolin. Results We found that, in addition to the expected effects on pre-ribosomal RNA accumulation and nucleolar structure, the absence of nucleolin results in a cell growth arrest, accumulation in G2, and an increase of apoptosis. Numerous nuclear alterations, including the presence of micronuclei, multiple nuclei or large nuclei are also observed. In addition, a large number of mitotic cells showed a defect in the control of centrosome duplication, as indicated by the presence of more than 2 centrosomes per cell associated with a multipolar spindle structure in the absence of nucleolin. This phenotype is very similar to that obtained with the inactivation of another nucleolar protein, B23. Conclusion Our findings uncovered a new role for nucleolin in cell division, and highlight the importance of nucleolar proteins for centrosome duplication.

  10. Exposed hydrophobic residues in human immunodeficiency virus type 1 Vpr helix-1 are important for cell cycle arrest and cell death.

    Directory of Open Access Journals (Sweden)

    R Anthony Barnitz

    Full Text Available The human immunodeficiency virus type 1 (HIV-1 accessory protein viral protein R (Vpr is a major determinant for virus-induced G2/M cell cycle arrest and cytopathicity. Vpr is thought to perform these functions through the interaction with partner proteins. The NMR structure of Vpr revealed solvent exposed hydrophobic amino acids along helices 1 and 3 of Vpr, which could be putative protein binding domains. We previously showed that the hydrophobic patch along helix-3 was important for G2/M blockade and cytopathicity. Mutations of the exposed hydrophobic residues along helix-1 were found to reduce Vpr-induced cell cycle arrest and cell death as well. The levels of toxicity during virion delivery of Vpr correlated with G2/M arrest. Thus, the exposed hydrophobic amino acids in the amino-terminal helix-1 are important for the cell cycle arrest and cytopathicity functions of Vpr.

  11. 6-Nitro-2-(3-hydroxypropyl-1H-benz[de]isoquinoline-1,3-dione, a potent antitumor agent, induces cell cycle arrest and apoptosis

    Directory of Open Access Journals (Sweden)

    Singh Shashank K

    2010-12-01

    Full Text Available Abstract Background Anticancer activities of several substituted naphthalimides (1H-benz[de]isoquinoline-1,3-diones are well documented. Some of them have undergone Phase I-II clinical trials. Presently a series of ten N-(hydroxyalkyl naphthalimides (compounds 1a-j were evaluated as antitumor agents. Methods Compounds 1a-j were initially screened in MOLT-4, HL-60 and U-937 human tumor cell lines and results were compared with established clinical drugs. Cytotoxicities of compounds 1d and 1i were further evaluated in a battery of human tumor cell lines and in normal human peripheral blood mononuclear cells. Cell cycle analysis of compound 1i treated MOLT-4 cells was studied by flow cytometry. Its apoptosis inducing effect was carried out in MOLT-4 and HL-60 cells by flow cytometry using annexin V-FITC/PI double staining method. The activities of caspase-3 and caspase-6 in MOLT-4 cells following incubation with compound 1i were measured at different time intervals. Morphology of the MOLT-4 cells after treatment with 1i was examined under light microscope and transmission electron microscope. 3H-Thymidine and 3H-uridine incorporation in S-180 cells in vitro following treatment with 8 μM concentration of compounds 1d and 1i were studied. Results 6-Nitro-2-(3-hydroxypropyl-1H-benz[de]isoquinoline-1,3-dione (compound 1i, has exhibited maximum activity as it induced significant cytotoxicity in 8 out of 13 cell lines employed. Interestingly it did not show any cytotoxicity against human PBMC (IC50 value 273 μM. Cell cycle analysis of compound 1i treated MOLT-4 cells demonstrated rise in sub-G1 fraction and concomitant accumulation of cells in S and G2/M phases, indicating up-regulation of apoptosis along with mitotic arrest and/or delay in exit of daughter cells from mitotic cycle respectively. Its apoptosis inducing effect was confirmed in flow cytometric study in MOLT-4 and the action was mediated by activation of both caspase 3 and 6. Light and

  12. The cancer-germline antigen SSX2 causes cell cycle arrest and DNA damage in cancer cells

    DEFF Research Database (Denmark)

    Greve, Katrine Buch Vidén; Lindgreen, Jonas; Terp, Mikkel Green;

    2011-01-01

    increase in the number of gamma-H2AX ‘DNA damage foci’, indicating replicative stress, which may lead to genomic instability. As the p53 tumor suppressor is an inducer of G1 arrest after DNA damage and often deregulated in cancer cells, we investigated if the growth reduction due to SSX2 expression was p53...... dependent. The growth reduction was similar in isogenic colon cancer cells with and without p53, indicating that SSX2 is able to inhibit the growth of cancer cells, even in absence of functional p53. Our results show that SSX2 acts as an inhibitor of cancer cell proliferation, possibly through replicative......The SSX family of cancer and germline antigens is mainly expressed in the germ cells of healthy individuals as well as wide range of cancers and is therefore potential targets for immunotherapy. However, little is known about the role of SSX proteins in tumorigenesis and normal cell function. Here...

  13. Hellebrigenin induces cell cycle arrest and apoptosis in human hepatocellular carcinoma HepG2 cells through inhibition of Akt.

    Science.gov (United States)

    Deng, Li-Juan; Hu, Li-Ping; Peng, Qun-Long; Yang, Xiao-Lin; Bai, Liang-Liang; Yiu, Anita; Li, Yong; Tian, Hai-Yan; Ye, Wen-Cai; Zhang, Dong-Mei

    2014-08-01

    Hellebrigenin, one of bufadienolides belonging to cardioactive steroids, was found in skin secretions of toads and plants of Helleborus and Kalanchoe genera. In searching for natural constituents with anti-hepatoma activities, we found that hellebrigenin, isolated from traditional Chinese medicine Venenum Bufonis, potently reduced the viability and colony formation of human hepatocellular carcinoma cells HepG2, and went on to explore the underlying molecular mechanisms. Our results demonstrated that hellebrigenin triggered DNA damage through DNA double-stranded breaks and subsequently induced cell cycle G2/M arrest associated with up-regulation of p-ATM (Ser(1981)), p-Chk2 (Tyr(68)), p-CDK1 (Tyr(15)) and Cyclin B1, and down-regulation of p-CDC25C (Ser(216)). It was also found that hellebrigenin induced mitochondrial apoptosis, characterized by Bax translocation to mitochondria, disruption of mitochondrial membrane potential, release of cytochrome c into cytosol and sequential activation of caspases and PARP. In addition, Akt expression and phosphorylation were inhibited by hellebrigenin, whereas Akt silencing with siRNA significantly blocked cell cycle arrest but enhanced apoptosis induced by hellebrigenin. Activation of Akt by human insulin-like growth factor I (hIGF-I) could obviously attenuate hellebrigenin-induced cell death. In summary, our study is the first to report the efficacy of hellebrigenin against HepG2 and elucidated its molecular mechanisms including DNA damage, mitochondria collapse, cell cycle arrest and apoptosis, which will contribute to the development of hellebrigenin into a chemotherapeutic agent in the treatment of liver cancer. PMID:24954031

  14. Induction of autophagy by proteasome inhibitor is associated with proliferative arrest in colon cancer cells

    International Nuclear Information System (INIS)

    The ubiquitin-proteasome system (UPS) and lysosome-dependent macroautophagy (autophagy) are two major intracellular pathways for protein degradation. Blockade of UPS by proteasome inhibitors has been shown to activate autophagy. Recent evidence also suggests that proteasome inhibitors may inhibit cancer growth. In this study, the effect of a proteasome inhibitor MG-132 on the proliferation and autophagy of cultured colon cancer cells (HT-29) was elucidated. Results showed that MG-132 inhibited HT-29 cell proliferation and induced G2/M cell cycle arrest which was associated with the formation of LC3+ autophagic vacuoles and the accumulation of acidic vesicular organelles. MG-132 also increased the protein expression of LC3-I and -II in a time-dependent manner. In this connection, 3-methyladenine, a Class III phosphoinositide 3-kinase inhibitor, significantly abolished the formation of LC3+ autophagic vacuoles and the expression of LC3-II but not LC3-I induced by MG-132. Taken together, this study demonstrates that inhibition of proteasome in colon cancer cells lowers cell proliferation and activates autophagy. This discovery may shed a new light on the novel function of proteasome in the regulation of autophagy and proliferation in colon cancer cells

  15. Imaging Bone Morphogenetic Protein 7 Induced Cell Cycle Arrest in Experimental Gliomas

    Directory of Open Access Journals (Sweden)

    Anke Klose

    2011-03-01

    Full Text Available Bone morphogenetic protein 7 (BMP-7 belongs to the superfamily of transforming growth factor β-like cytokines, which can act either as tumor suppressors or as tumor promoters depending on cell type and differentiation. Our investigations focused on analyzing the effects of BMP-7 during glioma cell proliferation in vitro and in vivo. BMP-7 treatment decreased the proliferation of Gli36ΔEGFR-LITG glioma cells up to 50%through a cell cycle arrest in the G1 phase but not by induction of apoptosis. This effect was mediated by the modulation of the expression and phosphorylation of cyclin-dependent kinase 2, cyclin-dependent kinase inhibitor p21, and downstream retinoblastoma protein. Furthermore, in vivo optical imaging of luciferase activity of Gli36ΔEGFR-LITG cells implanted intracranially into nude mice in the presence or absence of BMP-7 treatment corroborated the antiproliferative effects of this cytokine. This report clearly underlines the tumor-suppressive role of BMP-7 in glioma-derived cells. Taken together, our results indicate that manipulating the BMP/transforming growth factor β signaling cascade may serve as a new strategy for imaging-guided molecular-targeted therapy of malignant gliomas.

  16. Cordycepin Induces S Phase Arrest and Apoptosis in Human Gallbladder Cancer Cells

    Directory of Open Access Journals (Sweden)

    Xu-An Wang

    2014-07-01

    Full Text Available Gallbladder cancer is the most common malignant tumor of the biliary tract, and this condition has a rather dismal prognosis, with an extremely low five-year survival rate. To improve the outcome of unresectable and recurrent gallbladder cancer, it is necessary to develop new effective treatments and drugs. The purpose of the present study was to evaluate the effects of cordycepin on human gallbladder cells and uncover the molecular mechanisms responsible for these effects. The Cell Counting Kit-8 (CCK-8 and colony formation assays revealed that cordycepin affected the viability and proliferation of human gallbladder cancer cells in a dose- and time-dependent manner. Flow cytometric analysis showed that cordycepin induced S phase arrest in human gallbladder cancer cell lines(NOZ and GBC-SD cells. Cordycepin-induced apoptosis was observed using an Annexin V/propidium iodide (PI double-staining assay, and the mitochondrial membrane potential (ΔΨm decreased in a dose-dependent manner. Additionally, western blot analysis revealed the upregulation of cleaved-caspase-3, cleaved-caspase-9, cleaved-PARP and Bax and the downregulation of Bcl-2, cyclin A and Cdk-2 in cordycepin-treated cells. Moreover, cordycepin inhibited tumor growth in nude mice bearing NOZ tumors. Our results indicate that this drug may represent an effective treatment for gallbladder carcinoma.

  17. Sensitivity to sodium arsenite in human melanoma cells depends upon susceptibility to arsenite-induced mitotic arrest

    International Nuclear Information System (INIS)

    Arsenic induces clinical remission in patients with acute promyelocytic leukemia and has potential for treatment of other cancers. The current study examines factors influencing sensitivity to arsenic using human malignant melanoma cell lines. A375 and SK-Mel-2 cells were sensitive to clinically achievable concentrations of arsenite, whereas SK-Mel-3 and SK-Mel-28 cells required supratherapeutic levels for toxicity. Inhibition of glutathione synthesis, glutathione S-transferase (GST) activity, and multidrug resistance protein (MRP) transporter function attenuated arsenite resistance, consistent with studies suggesting that arsenite is extruded from the cell as a glutathione conjugate by MRP-1. However, MRP-1 was not overexpressed in resistant lines and GST-π was only slightly elevated. ICP-MS analysis indicated that arsenite-resistant SK-Mel-28 cells did not accumulate less arsenic than arsenite-sensitive A375 cells, suggesting that resistance was not attributable to reduced arsenic accumulation but rather to intrinsic properties of resistant cell lines. The mode of arsenite-induced cell death was apoptosis. Arsenite-induced apoptosis is associated with cell cycle alterations. Cell cycle analysis revealed arsenite-sensitive cells arrested in mitosis whereas arsenite-resistant cells did not, suggesting that induction of mitotic arrest occurs at lower intracellular arsenic concentrations. Higher intracellular arsenic levels induced cell cycle arrest in the S-phase and G2-phase in SK-Mel-3 and SK-Mel-28 cells, respectively. The lack of arsenite-induced mitotic arrest in resistant cell lines was associated with a weakened spindle checkpoint resulting from reduced expression of spindle checkpoint protein BUBR1. These data suggest that arsenite has potential for treatment of solid tumors but a functional spindle checkpoint is a prerequisite for a positive response to its clinical application

  18. Cancer Preventive Efficacy of Marine Carotenoid Fucoxanthin: Cell Cycle Arrest and Apoptosis

    Directory of Open Access Journals (Sweden)

    Thamaraiselvan Rengarajan

    2013-12-01

    Full Text Available Epidemiological investigations have shown that overcoming the risk of cancer is related to the consumption of green vegetables and fruits. Many compounds from different origins, such as terrestrial plants and marine and microbial sources, have been reported to have therapeutic effects of which marine sources are the most important because the diversity of marine life is more varied than other sources. Fucoxanthin is one important compound with a marine origin and belongs to the group of carotenoids; it can be found in marine brown seaweeds, macroalgae, and diatoms, all of which have remarkable biological properties. Numerous studies have shown that fucoxanthin has considerable medicinal potential and promising applications in human health. In this review, we summarize the anticancer effects of fucoxanthin through several different mechanisms including anti-proliferation, induction of apoptosis, cell cycle arrest and anti-angiogenesis, and its possible role in the treatment of cancer.

  19. Taxifolin enhances andrographolide-induced mitotic arrest and apoptosis in human prostate cancer cells via spindle assembly checkpoint activation.

    Directory of Open Access Journals (Sweden)

    Zhong Rong Zhang

    Full Text Available Andrographolide (Andro suppresses proliferation and triggers apoptosis in many types of cancer cells. Taxifolin (Taxi has been proposed to prevent cancer development similar to other dietary flavonoids. In the present study, the cytotoxic and apoptotic effects of the addition of Andro alone and Andro and Taxi together on human prostate carcinoma DU145 cells were assessed. Andro inhibited prostate cancer cell proliferation by mitotic arrest and activation of the intrinsic apoptotic pathway. Although the effect of Taxi alone on DU145 cell proliferation was not significant, the combined use of Taxi with Andro significantly potentiated the anti-proliferative effect of increased mitotic arrest and apoptosis by enhancing the cleavage of poly(ADP-ribose polymerase, and caspases-7 and -9. Andro together with Taxi enhanced microtubule polymerization in vitro, and they induced the formation of twisted and elongated spindles in the cancer cells, thus leading to mitotic arrest. In addition, we showed that depletion of MAD2, a component in the spindle assembly checkpoint (SAC, alleviated the mitotic block induced by the two compounds, suggesting that they trigger mitotic arrest by SAC activation. This study suggests that the anti-cancer activity of Andro can be significantly enhanced in combination with Taxi by disrupting microtubule dynamics and activating the SAC.

  20. Progestins reinitiate cell cycle progression in antiestrogen-arrested breast cancer cells through the B-isoform of progesterone receptor.

    Science.gov (United States)

    McGowan, Eileen M; Russell, Amanda J; Boonyaratanakornkit, Viroj; Saunders, Darren N; Lehrbach, Gillian M; Sergio, C Marcelo; Musgrove, Elizabeth A; Edwards, Dean P; Sutherland, Robert L

    2007-09-15

    Estrogen treatment of MCF-7 human breast cancer cells allows the reinitiation of synchronous cell cycle progression in antiestrogen-arrested cells. Here, we report that progestins also reinitiate cell cycle progression in this model. Using clonal cell lines derived from progesterone receptor (PR)-negative MCF-7M13 cells expressing wild-type or mutant forms of PRA and PRB, we show that this effect is mediated via PRB, not PRA. Cell cycle progression did not occur with a DNA-binding domain mutant of PRB but was unaffected by mutation in the NH(2)-terminal, SH3 domain interaction motif, which mediates rapid progestin activation of c-Src. Thus, the progestin-induced proliferative response in antiestrogen-inhibited cells is mediated primarily by the transcriptional activity of PRB. Analysis of selected cell cycle targets showed that progestin treatment induced levels of cyclin D1 expression and retinoblastoma protein (Rb) phosphorylation similar to those induced by estradiol. In contrast, progestin treatment resulted in only a 1.2-fold induction of c-Myc compared with a 10-fold induction by estradiol. These results support the conclusion that progestin, in a PRB-dependent manner, can overcome the growth-inhibitory effects of antiestrogens in estrogen receptor/PR-positive breast cancer cells by the induction of cyclin D1 expression. The mediation of this effect by PRB, but not PRA, further suggests a mechanism whereby abnormal regulation of the normal expression ratios of PR isoforms in breast cancer could lead to the attenuation of antiestrogen-mediated growth arrest. PMID:17875737

  1. Personal radon daughter dosimetry

    International Nuclear Information System (INIS)

    The conventional means of radon daughter exposure estimatikn for uranium miners in Canada is by grab sampling and time weighting. Personal dosimetry is a possible alternative method with its own advantages and limitations. The author poses basic questions with regard to two methods of radon daughter detection, thermoluminescent chips and track-etch film. An historical review of previous and current research and development programs in Canada and in other countries is presented, as are brief results and conclusions of each dosimeter evaluation

  2. Omega-3 Polyunsaturated Fatty Acids Trigger Cell Cycle Arrest and Induce Apoptosis in Human Neuroblastoma LA-N-1 Cells

    Directory of Open Access Journals (Sweden)

    Wai Wing So

    2015-08-01

    Full Text Available Omega-3 (n-3 fatty acids are dietary long-chain fatty acids with an array of health benefits. Previous research has demonstrated the growth-inhibitory effect of n-3 fatty acids on different cancer cell lines in vitro, yet their anti-tumor effects and underlying action mechanisms on human neuroblastoma LA-N-1 cells have not yet been reported. In this study, we showed that docosahexaenoic acid (DHA and eicosapentaenoic acid (EPA exhibited time- and concentration-dependent anti-proliferative effect on the human neuroblastoma LA-N-1 cells, but had minimal cytotoxicity on the normal or non-tumorigenic cells, as measured by MTT reduction assay. Mechanistic studies indicated that DHA and EPA triggered G0/G1 cell cycle arrest in LA-N-1 cells, as detected by flow cytometry, which was accompanied by a decrease in the expression of CDK2 and cyclin E proteins. Moreover, DHA and EPA could also induce apoptosis in LA-N-1 cells as revealed by an increase in DNA fragmentation, phosphatidylserine externalization and mitochondrial membrane depolarization. Up-regulation of Bax, activated caspase-3 and caspase-9 proteins, and down-regulation of Bcl-XL protein, might account for the occurrence of apoptotic events. Collectively, our results suggest that the growth-inhibitory effect of DHA and EPA on LA-N-1 cells might be mediated, at least in part, via triggering of cell cycle arrest and apoptosis. Therefore, DHA and EPA are potential anti-cancer agents which might be used for the adjuvant therapy or combination therapy with the conventional anti-cancer drugs for the treatment of some forms of human neuroblastoma with minimal toxicity.

  3. Neural innervation stimulates splenic TFF2 to arrest myeloid cell expansion and cancer.

    Science.gov (United States)

    Dubeykovskaya, Zina; Si, Yiling; Chen, Xiaowei; Worthley, Daniel L; Renz, Bernhard W; Urbanska, Aleksandra M; Hayakawa, Yoku; Xu, Ting; Westphalen, C Benedikt; Dubeykovskiy, Alexander; Chen, Duan; Friedman, Richard A; Asfaha, Samuel; Nagar, Karan; Tailor, Yagnesh; Muthupalani, Sureshkumar; Fox, James G; Kitajewski, Jan; Wang, Timothy C

    2016-01-01

    CD11b(+)Gr-1(+) myeloid-derived suppressor cells (MDSCs) expand in the spleen during cancer and promote progression through suppression of cytotoxic T cells. An anti-inflammatory reflex arc involving the vagus nerve and memory T cells is necessary for resolution of acute inflammation. Failure of this neural circuit could promote procarcinogenic inflammation and altered tumour immunity. Here we show that splenic TFF2, a secreted anti-inflammatory peptide, is released by vagally modulated memory T cells to suppress the expansion of MDSCs through CXCR4. Splenic denervation interrupts the anti-inflammatory neural arc, resulting in the expansion of MDSCs and colorectal cancer. Deletion of Tff2 recapitulates splenic denervation to promote carcinogenesis. Colorectal carcinogenesis could be suppressed through transgenic overexpression of TFF2, adenoviral transfer of TFF2 or transplantation of TFF2-expressing bone marrow. TFF2 is important to the anti-inflammatory reflex arc and plays an essential role in arresting MDSC proliferation. TFF2 offers a potential approach to prevent and to treat cancer. PMID:26841680

  4. Targeting TRPM2 Channels Impairs Radiation-Induced Cell Cycle Arrest and Fosters Cell Death of T Cell Leukemia Cells in a Bcl-2-Dependent Manner

    Directory of Open Access Journals (Sweden)

    Dominik Klumpp

    2016-01-01

    Full Text Available Messenger RNA data of lymphohematopoietic cancer lines suggest a correlation between expression of the cation channel TRPM2 and the antiapoptotic protein Bcl-2. The latter is overexpressed in various tumor entities and mediates therapy resistance. Here, we analyzed the crosstalk between Bcl-2 and TRPM2 channels in T cell leukemia cells during oxidative stress as conferred by ionizing radiation (IR. To this end, the effects of TRPM2 inhibition or knock-down on plasma membrane currents, Ca2+ signaling, mitochondrial superoxide anion formation, and cell cycle progression were compared between irradiated (0–10 Gy Bcl-2-overexpressing and empty vector-transfected Jurkat cells. As a result, IR stimulated a TRPM2-mediated Ca2+-entry, which was higher in Bcl-2-overexpressing than in control cells and which contributed to IR-induced G2/M cell cycle arrest. TRPM2 inhibition induced a release from G2/M arrest resulting in cell death. Collectively, this data suggests a pivotal function of TRPM2 in the DNA damage response of T cell leukemia cells. Apoptosis-resistant Bcl-2-overexpressing cells even can afford higher TRPM2 activity without risking a hazardous Ca2+-overload-induced mitochondrial superoxide anion formation.

  5. Eriocalyxin B induces apoptosis and cell cycle arrest in pancreatic adenocarcinoma cells through caspase- and p53-dependent pathways

    International Nuclear Information System (INIS)

    Pancreatic cancer is difficult to detect early and responds poorly to chemotherapy. A breakthrough in the development of new therapeutic agents is urgently needed. Eriocalyxin B (EriB), isolated from the Isodon eriocalyx plant, is an ent-kaurane diterpenoid with promise as a broad-spectrum anti-cancer agent. The anti-leukemic activity of EriB, including the underlying mechanisms involved, has been particularly well documented. In this study, we demonstrated for the first time EriB's potent cytotoxicity against four pancreatic adenocarcinoma cell lines, namely PANC-1, SW1990, CAPAN-1, and CAPAN-2. The effects were comparable to that of the chemotherapeutic camptothecin (CAM), but with much lower toxicity against normal human liver WRL68 cells. EriB's cytoxicity against CAPAN-2 cells was found to involve caspase-dependent apoptosis and cell cycle arrest at the G2/M phase. Moreover, the p53 pathway was found to be activated by EriB in these cells. Furthermore, in vivo studies showed that EriB inhibited the growth of human pancreatic tumor xenografts in BALB/c nude mice without significant secondary adverse effects. These results suggest that EriB should be considered a candidate for pancreatic cancer treatment. -- Highlights: ► We study Eriocalyxin B (EriB)'s cytotoxic effects on pancreatic cancer cell lines. ► EriB inhibits cell proliferation via mediation of apoptosis and cell cycle arrest. ► The effects are involved in caspase-dependent apoptosis and p53 pathway. ► In vivo study also shows EriB inhibits the growth of human pancreatic tumor. ► EriB can be a good candidate for chemotherapy in pancreatic cancer.

  6. Eriocalyxin B induces apoptosis and cell cycle arrest in pancreatic adenocarcinoma cells through caspase- and p53-dependent pathways

    Energy Technology Data Exchange (ETDEWEB)

    Li, Lin [School of Biomedical Sciences, The Chinese University of Hong Kong, Hong Kong (China); Institute of Chinese Medicine, The Chinese University of Hong Kong, Hong Kong (China); State Key Laboratory of Phytochemistry and Plant Resources in West China, The Chinese University of Hong Kong, Hong Kong (China); Yue, Grace G.L. [Institute of Chinese Medicine, The Chinese University of Hong Kong, Hong Kong (China); State Key Laboratory of Phytochemistry and Plant Resources in West China, The Chinese University of Hong Kong, Hong Kong (China); Lau, Clara B.S. [Institute of Chinese Medicine, The Chinese University of Hong Kong, Hong Kong (China); Institute of Chinese Medicine, The Chinese University of Hong Kong, Hong Kong (China); Sun, Handong [State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, CAS, Yunnan (China); Fung, Kwok Pui [School of Biomedical Sciences, The Chinese University of Hong Kong, Hong Kong (China); Institute of Chinese Medicine, The Chinese University of Hong Kong, Hong Kong (China); State Key Laboratory of Phytochemistry and Plant Resources in West China, The Chinese University of Hong Kong, Hong Kong (China); Leung, Ping Chung [Institute of Chinese Medicine, The Chinese University of Hong Kong, Hong Kong (China); State Key Laboratory of Phytochemistry and Plant Resources in West China, The Chinese University of Hong Kong, Hong Kong (China); Han, Quanbin, E-mail: simonhan@hkbu.edu.hk [Institute of Chinese Medicine, The Chinese University of Hong Kong, Hong Kong (China); State Key Laboratory of Phytochemistry and Plant Resources in West China, The Chinese University of Hong Kong, Hong Kong (China); School of Chinese Medicine, The Hong Kong Baptist University, Hong Kong (China); Leung, Po Sing, E-mail: psleung@cuhk.edu.hk [School of Biomedical Sciences, The Chinese University of Hong Kong, Hong Kong (China)

    2012-07-01

    Pancreatic cancer is difficult to detect early and responds poorly to chemotherapy. A breakthrough in the development of new therapeutic agents is urgently needed. Eriocalyxin B (EriB), isolated from the Isodon eriocalyx plant, is an ent-kaurane diterpenoid with promise as a broad-spectrum anti-cancer agent. The anti-leukemic activity of EriB, including the underlying mechanisms involved, has been particularly well documented. In this study, we demonstrated for the first time EriB's potent cytotoxicity against four pancreatic adenocarcinoma cell lines, namely PANC-1, SW1990, CAPAN-1, and CAPAN-2. The effects were comparable to that of the chemotherapeutic camptothecin (CAM), but with much lower toxicity against normal human liver WRL68 cells. EriB's cytoxicity against CAPAN-2 cells was found to involve caspase-dependent apoptosis and cell cycle arrest at the G2/M phase. Moreover, the p53 pathway was found to be activated by EriB in these cells. Furthermore, in vivo studies showed that EriB inhibited the growth of human pancreatic tumor xenografts in BALB/c nude mice without significant secondary adverse effects. These results suggest that EriB should be considered a candidate for pancreatic cancer treatment. -- Highlights: ► We study Eriocalyxin B (EriB)'s cytotoxic effects on pancreatic cancer cell lines. ► EriB inhibits cell proliferation via mediation of apoptosis and cell cycle arrest. ► The effects are involved in caspase-dependent apoptosis and p53 pathway. ► In vivo study also shows EriB inhibits the growth of human pancreatic tumor. ► EriB can be a good candidate for chemotherapy in pancreatic cancer.

  7. Naphthalimides Induce G2 Arrest Through the ATM-Activated Chk2-Executed Pathway in HCT116 Cells

    Directory of Open Access Journals (Sweden)

    Hong Zhu

    2009-11-01

    Full Text Available Naphthalimides, particularly amonafide and 2-(2-dimethylamino-6-thia-2-aza-benzo[def]chrysene-1,3-diones (R16, have been identified to possess anticancer activities and to induce G2-M arrest through inhibiting topoisomerase II accompanied by Chk1 degradation. The current study was designed to precisely dissect the signaling pathway(s responsible for the naphthalimide-induced cell cycle arrest in human colon carcinoma HCT116 cells. Using phosphorylated histone H3 and mitotic protein monoclonal 2 as mitosis markers, we first specified the G2 arrest elicited by the R16 and amonafide. Then, R16 and amonafide were revealed to induce phosphorylation of the DNA damage sensor ataxia telangiectasia-mutated (ATM responding to DNA double-strand breaks (DSBs. Inhibition of ATM by both the pharmacological inhibitor caffeine and the specific small interference RNA (siRNA rescued the G2 arrest elicited by R16, indicating its ATM-dependent characteristic. Furthermore, depletion of Chk2, but not Chk1 with their corresponding siRNA, statistically significantly reversed the R16- and amonafide-triggered G2 arrest. Moreover, the naphthalimides phosphorylated Chk2 in an ATM-dependent manner but induced Chk1 degradation. These data indicate that R16 and amonafide preferentially used Chk2 as evidenced by the differential ATM-executed phosphorylation of Chk1 and Chk2. Thus, a clear signaling pathway can be established, in which ATM relays the DNA DSBs signaling triggered by the naphthalimides to the checkpoint kinases, predominantly to Chk2,which finally elicits G2 arrest. The mechanistic elucidation not only favors the development of the naphthalimides as anticancer agents but also provides an alternative strategy of Chk2 inhibition to potentiate the anticancer activities of these agents.

  8. Inhibition of Survivin and Aurora B Kinase Sensitizes Mesothelioma Cells by Enhancing Mitotic Arrests

    International Nuclear Information System (INIS)

    Purpose: Survivin, a member of the inhibitor of apoptosis gene family, has also been shown to regulate mitosis. It binds Aurora B kinase and the inner centromere protein to form the chromosome passenger complex. Both Aurora B and survivin are overexpressed in many tumors. In this study, we examined whether irradiation affected survivin and Aurora B expression in mesothelioma cells, and how inhibition of these molecules affected radiosensitivity. Methods and Materials: ZM447439 and survivin antisense oligonucleotides were used to inhibit survivin and Aurora B kinase respectively. Western blot was performed to determine the expression of survivin, Aurora B, phosphorylated-histone H3 (Ser 10), and caspase cleavage. Multinucleated cells were counted using flow cytometry, and cell survival after treatment was determined using clonogenic assay. Results: At 3-Gy irradiation an increase was observed in levels of survivin and Aurora B as well as the kinase activity of Aurora B, with an increase in G2/M phase. The radiation-induced upregulation of these molecules was effectively attenuated by antisense oligonucleotides against survivin and a small-molecule inhibitor of Aurora B, ZM447439. Dual inhibition of survivin and Aurora B synergistically radiosensitized mesothelioma cells with a dose enhancement ratio of 2.55. This treatment resulted in increased formation of multinucleated cells after irradiation but did not increase levels of cleaved caspase 3. Conclusion: Inhibition of survivin and Aurora B induces mitotic cell arrest in mesothelioma cells after irradiation. These two proteins may be potential therapeutic targets for the enhancement of radiotherapy in malignant pleural mesothelioma

  9. Immunosuppressive activity of pogostone on T cells: Blocking proliferation via S phase arrest.

    Science.gov (United States)

    Su, Ji-Yan; Luo, Xia; Zhang, Xiao-Jun; Deng, Xiang-Liang; Su, Zi-Ren; Zhou, Lian; Li, Shan-Shan; Dai, Zhenhua; Xu, Yang; Lai, Xiao-Ping

    2015-06-01

    Pogostone (PO) is one of the major chemical constituents of the essential oil of Pogostemon cablin (Blanco) Benth. In the present study, the effect of PO on T cell responsiveness was investigated to explore its potential in immunosuppression by a Concanavalin A (ConA)-stimulation model using splenocytes isolated from C57BL/6 mice. Cytotoxicity by PO on normal splenocytes was evaluated by MTS assays. Characteristics of apoptosis, proliferation, and cell cycle were analyzed by flow cytometry. Related expressions of cyclins and cyclin-dependent kinases (CDKs) were also determined by flow cytometry. Inflammatory cytokine profiling was performed emplying cytometric beads assays (CBA). Moreover, the T cell-mediated delayed Type hepersensity (DTH) model was applied to evaluate the immunosuppressive activity of PO. Neither viability reduction in normal splenocytes nor apoptosis in ConA-stimulated splenocytes was observed under PO treatments. Meanwhile, PO remarkably reduced the total population of ConA-stimulated T cell, blocked T cell proliferation induced by Con A, and inhibited the production of IFN-γ and IL-10. This blockade of stimulated T cell proliferation by PO was likely attributed to down-regulation of cyclin E, cyclin B and CDK1 and the subsequent S-phase arrest. Additionally, PO could inhibit the DTH reaction by alleviating ear swelling and inflammatory infiltrations in the DNCB-challenged ear. Taken together, PO exhibited an immunosuppressive property by directly blocking T cell proliferation as well as altering inflammatory cytokine profile, suggesting that PO may have clinical implications for treating autoimmune diseases and other immune-based disorders. PMID:25912345

  10. The p75NTR tumor suppressor induces cell cycle arrest facilitating caspase mediated apoptosis in prostate tumor cells

    International Nuclear Information System (INIS)

    The p75 neurotrophin receptor (p75NTR) is a death receptor which belongs to the tumor necrosis factor receptor super-family of membrane proteins. This study shows that p75NTR retarded cell cycle progression by induced accumulation of cells in G0/G1 and a reduction in the S phase of the cell cycle. The rescue of tumor cells from cell cycle progression by a death domain deleted (ΔDD) dominant-negative antagonist of p75NTR showed that the death domain transduced anti-proliferative activity in a ligand-independent manner. Conversely, addition of NGF ligand rescued retardation of cell cycle progression with commensurate changes in components of the cyclin/cdk holoenzyme complex. In the absence of ligand, p75NTR-dependent cell cycle arrest facilitated an increase in apoptotic nuclear fragmentation of the prostate cancer cells. Apoptosis of p75NTR expressing cells occurred via the intrinsic mitochondrial pathway leading to a sequential caspase-9 and -7 cascade. Since the death domain deleted dominant-negative antagonist of p75NTR rescued intrinsic caspase associated apoptosis in PC-3 cells, this shows p75NTR was integral to ligand independent induction of apoptosis. Moreover, the ability of ligand to ameliorate the p75NTR-dependent intrinsic apoptotic cascade indicates that NGF functioned as a survival factor for p75NTR expressing prostate cancer cells

  11. Indole-3-carbinol inhibits nasopharyngeal carcinoma growth through cell cycle arrest in vivo and in vitro.

    Directory of Open Access Journals (Sweden)

    Zhe Chen

    Full Text Available Nasopharyngeal carcinoma is a common malignant tumor in the head and neck. Because of frequent recurrence and distant metastasis which are the main causes of death, better treatment is needed. Indole-3-carbinol (I3C, a natural phytochemical found in the vegetables of the cruciferous family, shows anticancer effect through various signal pathways. I3C induces G1 arrest in NPC cell line with downregulation of cell cycle-related proteins, such as CDK4, CDK6, cyclin D1 and pRb. In vivo, nude mice receiving I3C protectively or therapeutically exhibited smaller tumors than control group after they were inoculated with nasopharyngeal carcinoma cells. The expression of CDK4, CDK6, cyclin D1 and pRb in preventive treatment group and drug treatment group both decreased compared with the control group. We conclude that I3C can inhibit the growth of NPC in vitro and in vivo by suppressing the expression of CDK and cyclin families. The drug was safe and had no toxic effects on normal tissues and organs.

  12. Supercritical carbon dioxide extract of Physalis peruviana induced cell cycle arrest and apoptosis in human lung cancer H661 cells.

    Science.gov (United States)

    Wu, Shu-Jing; Chang, Shun-Pang; Lin, Doung-Liang; Wang, Shyh-Shyan; Hou, Fwu-Feuu; Ng, Lean-Teik

    2009-06-01

    Physalis peruviana L. (PP) is a popular folk medicine used for treating cancer, leukemia, hepatitis, rheumatism and other diseases. In this study, our objectives were to examine the total flavonoid and phenol content of different PP extracts (aqueous: HWEPP; ethanolic: EEPP; supercritical carbon dioxide: SCEPP-0, SCEPP-4 and SCEPP-5) and their antiproliferative effects in human lung cancer H661 cells. Among all the extracts tested, results showed that SCEPP-5 possessed the highest total flavonoid (226.19 +/- 4.15 mg/g) and phenol (100.82 +/- 6.25 mg/g) contents. SCEPP-5 also demonstrated the most potent inhibitory effect on H661 cell proliferation. Using DNA ladder and flow cytometry analysis, SCEPP-5 effectively induced H661 cell apoptosis as demonstrated by the accumulation of Sub-G1 peak and fragmentation of DNA. SCEPP-5 not only induced cell cycle arrest at S phase, it also up-regulated the expression of pro-apoptotic protein (Bax) and down-regulated the inhibitor of apoptosis protein (IAP). Furthermore, the apoptotic induction in H661 cells was found to associate with an elevated p53 protein expression, cytochrome c release, caspase-3 activation and PARP cleavage. Taken together, these results conclude that SCEPP-5 induced cell cycle arrest at S phase, and its apoptotic induction could be mediated through the p53-dependent pathway and modification of Bax and XIAP proteins expression. The results have also provided important pharmacological backgrounds for the potential use of PP supercritical fluid extract as products for cancer prevention. PMID:19425186

  13. Proteotoxic stress induces a cell-cycle arrest by stimulating Lon to degrade the replication initiator DnaA.

    Science.gov (United States)

    Jonas, Kristina; Liu, Jing; Chien, Peter; Laub, Michael T

    2013-08-01

    The decision to initiate DNA replication is a critical step in the cell cycle of all organisms. Cells often delay replication in the face of stressful conditions, but the underlying mechanisms remain incompletely defined. Here, we demonstrate in Caulobacter crescentus that proteotoxic stress induces a cell-cycle arrest by triggering the degradation of DnaA, the conserved replication initiator. A depletion of available Hsp70 chaperone, DnaK, either through genetic manipulation or heat shock, induces synthesis of the Lon protease, which can directly degrade DnaA. Unexpectedly, we find that unfolded proteins, which accumulate following a loss of DnaK, also allosterically activate Lon to degrade DnaA, thereby ensuring a cell-cycle arrest. Our work reveals a mechanism for regulating DNA replication under adverse growth conditions. Additionally, our data indicate that unfolded proteins can actively and directly alter substrate recognition by cellular proteases. PMID:23911325

  14. A bacterial type III effector family uses the papain-like hydrolytic activity to arrest the host cell cycle

    OpenAIRE

    Yao, Qing; Cui, Jixin; Zhu, Yongqun; Wang, Guolun; Hu, Liyan; Long, Chengzu; Cao, Ran; Liu, Xinqi; Huang, Niu; Chen, She; Liu, LiPing; Shao, Feng

    2009-01-01

    Pathogenic bacteria deliver effector proteins into host cells through the type III secretion apparatus to modulate the host function. We identify a family of proteins, homologous to the type III effector Cif from enteropathogenic Escherichia coli, in pathogens including Yersinia, Photorhabdus, and Burkholderia that contain functional type III secretion systems. Like Cif, this family of proteins is capable of arresting the host cell cycle at G2/M. Structure of one of the family members, Cif ho...

  15. Resveratrol induces cell cycle arrest and apoptosis in malignant NK cells via JAK2/STAT3 pathway inhibition.

    Directory of Open Access Journals (Sweden)

    Ly Quoc Trung

    Full Text Available Natural killer (NK cell malignancies, particularly aggressive NK cell leukaemias and lymphomas, have poor prognoses. Although recent regimens with L-asparaginase substantially improved outcomes, novel therapeutic approaches are still needed to enhance clinical response. Resveratrol, a naturally occurring polyphenol, has been extensively studied for its anti-inflammatory, cardioprotective and anti-cancer activities. In this study, we investigated the potential anti-tumour activities of resveratrol against the NK cell lines KHYG-1, NKL, NK-92 and NK-YS. Resveratrol induced robust G0/G1 cell cycle arrest, significantly suppressed cell proliferation and induced apoptosis in a dose- and time-dependent manner for all four cell lines. In addition, resveratrol suppressed constitutively active STAT3 in all the cell lines and inhibited JAK2 phosphorylation but had no effect on other upstream mediators of STAT3 activation, such as PTEN, TYK2, and JAK1. Resveratrol also induced downregulation of the anti-apoptotic proteins MCL1 and survivin, two downstream effectors of the STAT3 pathway. Finally, resveratrol induced synergistic effect on the apoptotic and antiproliferative activities of L-asparaginase against KHYG-1, NKL and NK-92 cells. These results suggest that resveratrol may have therapeutic potential against NK cell malignancies. Furthermore, our finding that resveratrol is a bonafide JAK2 inhibitor extends its potential benefits to other diseases with dysregulated JAK2 signaling.

  16. Strategic cell-cycle regulatory features that provide mammalian cells with tunable G1 length and reversible G1 arrest.

    Directory of Open Access Journals (Sweden)

    Benjamin Pfeuty

    Full Text Available Transitions between consecutive phases of the eukaryotic cell cycle are driven by the catalytic activity of selected sets of cyclin-dependent kinases (Cdks. Yet, their occurrence and precise timing is tightly scheduled by a variety of means including Cdk association with inhibitory/adaptor proteins (CKIs. Here we focus on the regulation of G1-phase duration by the end of which cells of multicelled organisms must decide whether to enter S phase or halt, and eventually then, differentiate, senesce or die to obey the homeostatic rules of their host. In mammalian cells, entry in and progression through G1 phase involve sequential phosphorylation and inactivation of the retinoblastoma Rb proteins, first, by cyclin D-Cdk4,6 with the help of CKIs of the Cip/Kip family and, next, by the cyclin E-Cdk2 complexes that are negatively regulated by Cip/Kip proteins. Using a dynamical modeling approach, we show that the very way how the Rb and Cip/Kip regulatory modules interact differentially with cyclin D-Cdk4,6 and cyclin E-Cdk2 provides to mammalian cells a powerful means to achieve an exquisitely-sensitive control of G1-phase duration and fully reversible G1 arrests. Consistently, corruption of either one of these two modules precludes G1 phase elongation and is able to convert G1 arrests from reversible to irreversible. This study unveils fundamental design principles of mammalian G1-phase regulation that are likely to confer to mammalian cells the ability to faithfully control the occurrence and timing of their division process in various conditions.

  17. Peroxisome proliferator-activated receptor γ ligands induce cell cycle arrest and apoptosis in human renal carcinoma cell lines

    Institute of Scientific and Technical Information of China (English)

    Feng-guang YANG; Zhi-wen ZHANG; Dian-qi XIN; Chang-jin SHI; Jie-ping WU; Ying-lu GUO; You-fei GUAN

    2005-01-01

    Aim: To study the effect of peroxisome proliferator-actived receptor γ (PPARγ)ligands on cell proliferation and apoptosis in human renal carcinoma cell lines.Methods: The expression of PPARγ was investigated by reverse transcriptase polymerase chain reaction (RT-PCR), Western blot and immunohistochemistry.The effect of thiazolidinedione (TZD) PPARγ ligands on growth of renal cell carcinoma (RCC) cells was measured by MTT assay and flow cytometric analysis. Cell death ELISA, Hoechst 33342 fluorescent staining and DNA ladder assay were used to observe the effects of PPARγ ligands on apoptosis. Regulatory proteins of cell cycle and apoptosis were detected by Western blot analysis. Results:PPARγ was expressed at much higher levels in renal tumors than in the normal kidney (2.16±0.85 vs 0.90±0.73; P<0.01 ). TZD PPARγ ligands inhibited RCC cell growth in a dose-dependent manner with IC50 values of 7.08 μmol/L and 11.32 μmol/L for pioglitazone, and 5.71 μmol/L and 8.38 μmol/L for troglitazone in 786-O and A498 cells, respectively. Cell cycle analysis showed a G0/G1 arrest in human RCC cells following 24-h exposure to TZD. Analysis of cell cycle regulatory proteins revealed that TZD decreased the protein levels of proliferating cell nuclear antigen, pRb, cyclin D1, and Cdk4 but increased the levels of p21 and p27 in a timedependent manner. Furthermore, high doses of TZD induced massive apoptosis in renal cancer cells, with increased Bax expression and decreased Bcl-2 expression.Conclusion: TZD PPARγ ligands showed potent inhibitory effect on proliferation,and could induce apoptosis in RCC cells. These results suggest that ligands for PPARγ have potential antitumor effects on renal carcinoma cells.

  18. Mitotic arrest of breast cancer MDA-MB-231 cells by a halogenated thieno[3,2-d]pyrimidine

    OpenAIRE

    Ross, Christina R.; Temburnikar, Kartik W; Wilson, Gerald M.; Seley-Radtke, Katherine L.

    2015-01-01

    Halogenated thieno[3,2-d]pyrimidines exhibit antiproliferative activity against a variety of cancer cell models, such as the mouse lymphocytic leukemia cell line L1210 in which they induce apoptosis independent of cell cycle arrest. Here we assessed these activities on MDA-MB-231 cells, a well-established model of aggressive, metastatic breast cancer. While 2,4-dichloro[3,2-d]pyrimidine was less toxic to MDA-MB-231 cells than previously observed in the L1210 model, flow cytometry analysis sho...

  19. Glioblastoma Stem Cells Respond to Differentiation Cues but Fail to Undergo Commitment and Terminal Cell-Cycle Arrest

    Directory of Open Access Journals (Sweden)

    Helena Carén

    2015-11-01

    Full Text Available Glioblastoma (GBM is an aggressive brain tumor whose growth is driven by stem cell-like cells. BMP signaling triggers cell-cycle exit and differentiation of GBM stem cells (GSCs and, therefore, might have therapeutic value. However, the epigenetic mechanisms that accompany differentiation remain poorly defined. It is also unclear whether cell-cycle arrest is terminal. Here we find only a subset of GSC cultures exhibit astrocyte differentiation in response to BMP. Although overtly differentiated non-cycling astrocytes are generated, they remain vulnerable to cell-cycle re-entry and fail to appropriately reconfigure DNA methylation patterns. Chromatin accessibility mapping identified loci that failed to alter in response to BMP and these were enriched in SOX transcription factor-binding motifs. SOX transcription factors, therefore, may limit differentiation commitment. A similar propensity for cell-cycle re-entry and de-differentiation was observed in GSC-derived oligodendrocyte-like cells. These findings highlight significant obstacles to BMP-induced differentiation as therapy for GBM.

  20. Phytometabolite Dehydroleucodine Induces Cell Cycle Arrest, Apoptosis, and DNA Damage in Human Astrocytoma Cells through p73/p53 Regulation.

    Directory of Open Access Journals (Sweden)

    Natalia Bailon-Moscoso

    Full Text Available Accumulating evidence supports the idea that secondary metabolites obtained from medicinal plants (phytometabolites may be important contributors in the development of new chemotherapeutic agents to reduce the occurrence or recurrence of cancer. Our study focused on Dehydroleucodine (DhL, a sesquiterpene found in the provinces of Loja and Zamora-Chinchipe. In this study, we showed that DhL displayed cytostatic and cytotoxic activities on the human cerebral astrocytoma D384 cell line. With lactone isolated from Gynoxys verrucosa Wedd, a medicinal plant from Ecuador, we found that DhL induced cell death in D384 cells by triggering cell cycle arrest and inducing apoptosis and DNA damage. We further found that the cell death resulted in the increased expression of CDKN1A and BAX proteins. A marked induction of the levels of total TP73 and phosphorylated TP53, TP73, and γ-H2AX proteins was observed in D384 cells exposed to DhL, but no increase in total TP53 levels was detected. Overall these studies demonstrated the marked effect of DhL on the diminished survival of human astrocytoma cells through the induced expression of TP73 and phosphorylation of TP73 and TP53, suggesting their key roles in the tumor cell response to DhL treatment.

  1. Temperature stress promotes cell division arrest in Xanthomonas citri subsp. citri.

    Science.gov (United States)

    Sumares, Júlia A P; Morão, Luana Galvão; Martins, Paula M M; Martins, Daniela A B; Gomes, Eleni; Belasque, José; Ferreira, Henrique

    2016-04-01

    Citrus canker is an economically important disease that affects orange production in some of the most important producing areas around the world. It represents a great threat to the Brazilian and North American citriculture, particularly to the states of São Paulo and Florida, which together correspond to the biggest orange juice producers in the world. The etiological agent of this disease is the Gram-negative bacterium Xanthomonas citri subsp. citri (Xcc), which grows optimally in laboratory cultures at ~30°C. To investigate how temperatures differing from 30°C influence the development of Xcc, we subjected the bacterium to thermal stresses, and afterward scored its recovery capability. In addition, we analyzed cell morphology and some markers of essential cellular processes that could indicate the extent of the heat-induced damage. We found that the exposure of Xcc to 37°C for a period of 6 h led to a cell cycle arrest at the division stage. Thermal stress might have also interfered with the DNA replication and/or the chromosome segregation apparatuses, since cells displayed an increased number of sister origins side-by-side within rods. Additionally, Xcc treated at 37°C was still able to induce citrus canker symptoms, showing that thermal stress did not affect the ability of Xcc to colonize the host citrus. At 40-42°C, Xcc lost viability and became unable to induce disease symptoms in citrus. Our results provide evidence about essential cellular mechanisms perturbed by temperature, and can be potentially explored as a new method for Xanthomonas citri synchronization in cell cycle studies, as well as for the sanitation of plant material. PMID:26663580

  2. Paris chinensis dioscin induces G2/M cell cycle arrest and apoptosis in human gastric cancer SGC-7901 cells

    Institute of Scientific and Technical Information of China (English)

    Lin-Lin Gao; Fu-Rong Li; Peng Jiao; Ming-Feng Yang; Xiao-Jun Zhou; Yan-Hong Si; Wen-Jian Jiang; Ting-Ting Zheng

    2011-01-01

    AIM: To investigate the anti-tumor effects of Paris chinensis dioscin (PCD) and mechanisms regarding cell cycle regulation and apoptosis in human gastric cancer SGC-7901 cells.METHODS: Cell viability was analyzed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide assay. Cell apoptosis was evaluated by flow cytometry and laser scanning confocal microscope (LSCM) using Annexin-V/propidium iodide (PI) staining, and the cell cycle was evaluated using PI staining with flow cytometry. Intracellular calcium ions were detected under fluorescence microscope. The expression of cell cycle and apoptosis-related proteins cyclin B1, CDK1, cytochrome C and caspase-3 was measured by immunohistochemical staining. RESULTS: PCD had an anti-proliferation effect on human gastric cancer SGC-7901 cells in a dose- and time-dependent manner. After treatment of SGC-7901 cells with PCD, apoptosis appeared in SGC-7901 cells. Morphological changes typical of apoptosis were also observed with LSCM by Annexin V/PI staining, and the cell number of the G0/G1 phase was decreased, while the number of cells in the G2/M phase was increased. Cell cycle-related proteins, such as cyclin B1 and CDK1, were all down-regulated, but caspase-3 and cytochrome C were up-regulated. Moreover, intracellular calcium accumulation occurred in PCD-treated cells. CONCLUSION: G2/M phase arrest and apoptosis induced by PCD are associated with the inhibition of CDK-activating kinase activity and the activation of Ca2+-related mitochondrion pathway in SGC-7901 cells.

  3. Vapor of volatile oils from Litsea cubeba seed induces apoptosis and causes cell cycle arrest in lung cancer cells.

    Directory of Open Access Journals (Sweden)

    Soma Seal

    Full Text Available Non-small cell lung carcinoma (NSCLC is a major killer in cancer related human death. Its therapeutic intervention requires superior efficient molecule(s as it often becomes resistant to present chemotherapy options. Here we report that vapor of volatile oil compounds obtained from Litsea cubeba seeds killed human NSCLC cells, A549, through the induction of apoptosis and cell cycle arrest. Vapor generated from the combined oils (VCO deactivated Akt, a key player in cancer cell survival and proliferation. Interestingly VCO dephosphorylated Akt at both Ser(473 and Thr(308; through the suppression of mTOR and pPDK1 respectively. As a consequence of this, diminished phosphorylation of Bad occurred along with the decreased Bcl-xL expression. This subsequently enhanced Bax levels permitting the release of mitochondrial cytochrome c into the cytosol which concomitantly activated caspase 9 and caspase 3 resulting apoptotic cell death. Impairment of Akt activation by VCO also deactivated Mdm2 that effected overexpression of p53 which in turn upregulated p21 expression. This causes enhanced p21 binding to cyclin D1 that halted G1 to S phase progression. Taken together, VCO produces two prong effects on lung cancer cells, it induces apoptosis and blocked cancer cell proliferation, both occurred due to the deactivation of Akt. In addition, it has another crucial advantage: VCO could be directly delivered to lung cancer tissue through inhalation.

  4. Fas expression correlates with human germ cell degeneration in meiotic and post-meiotic arrest of spermatogenesis.

    Science.gov (United States)

    Francavilla, Sandro; D'Abrizio, Piera; Cordeschi, Giuliana; Pelliccione, Fiore; Necozione, Stefano; Ulisse, Salvatore; Properzi, Giuliana; Francavilla, Felice

    2002-03-01

    Degeneration of human male germ cells was analysed by means of light (LM) and transmission electron (TEM) microscopy. The frequency of degenerating cells was correlated with that of Fas-expressing germ cells in human testes with normal spermatogenesis (n = 10), complete early maturation arrest (EMA) (n = 10) or incomplete late maturation arrest (LMA; n = 10) of spermatogenesis. LM analysis of testis sections with normal spermatogenesis indicated that degenerating germ cells were localized in the adluminal compartment of the seminiferous epithelium. TEM showed that apoptotic cells were mostly primary spermatocytes and, to a lesser extent, round or early elongating spermatids. Apoptotic germ cells appeared to be eliminated either in the seminiferous lumen or by Sertoli cell phagocytosis. An increased number of degenerating cells was observed in testes with LMA as compared with normal testes and testes with EMA of spermatogenesis (P < 0.001, Wilcoxon's rank sum test). Comparison of these results with those obtained from immunohistochemistry experiments demonstrated a tight correlation between the number of apoptotic cells and the number of Fas-expressing germ cells (P = 0.001, Spearman's rank = 0.69). These findings suggest that altered meiotic and post-meiotic germ cell maturation might be associated with an up-regulation of Fas gene expression capable of triggering apoptotic elimination of defective germ cells. PMID:11870228

  5. Interaction of E-cadherin and PTEN regulates morphogenesis and growth arrest in human mammary epithelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Fournier, Marcia V.; Fata, Jimmie E.; Martin, Katherine J.; Yaswen, Paul; Bissell, Mina J.

    2009-06-03

    PTEN is a dual function phosphatase with tumor suppressor function compromised in a wide spectrum of cancers. Because tissue polarity and architecture are crucial modulators of normal and malignant behavior, we postulated that PTEN may play a role in maintenance of tissue integrity. We used two non-malignant human mammary epithelial cell lines (HMECs) that form polarized, growth-arrested structures (acini) when cultured in 3-dimensional laminin-rich extracellular matrix gels (3D lrECM). As acini begin to form, PTEN accumulates in both the cytoplasm, and at cell-cell contacts where it colocalizes with E-cadherin/{beta}-catenin complex. Reduction of PTEN levels by shRNA in lrECM prevents formation of organized breast acini and disrupts growth arrest. Importantly, disruption of acinar polarity and cell-cell contact by E-cadherin function-blocking antibodies reduces endogenous PTEN protein levels and inhibits its accumulation at cell-cell contacts. Conversely, in SKBR3 breast cancer cells lacking endogenous E-cadherin expression, exogenous introduction of E-cadherin gene causes induction of PTEN expression and its accumulation at sites of cell interactions. These studies provide evidence that E-cadherin regulates both the PTEN protein levels and its recruitment to cell-cell junctions in 3D lrECM indicating a dynamic reciprocity between architectural integrity and the levels and localization of PTEN. This interaction thus appears to be a critical integrator of proliferative and morphogenetic signaling in breast epithelial cells.

  6. Novel Suicide Ligands of Tubulin Arrest Cancer Cells in S-Phase

    Directory of Open Access Journals (Sweden)

    Ashley Davis

    1999-12-01

    Full Text Available It is presently accepted that the mechanism of action for all anti-tumor tubulin ligands involves the perturbation of microtubule dynamics during the G2/M phase of cell division and subsequent entry into apoptosis 1]. In this report, we challenge the established dogma by describing a unique mechanism of action caused by a novel series of tubulin ligands, halogenated derivatives of acetamido benzoyl ethyl ester. We have developed a suicide ligand for tubulin, which covalently attaches to the target and shows potent cancericidal activity in tissue culture assays and in animal tumor models. These compounds target early S-phase at the G1/S transition rather than the G2/M phase and mitotic arrest. Bcl-2 phosphorylation, a marker of mitotic microtubule inhibition by other tubulin ligands was dramatically altered, phosphorylation was rapid and biphasic rather than a slow linear event. The halogenated ethyl ester series of derivatives thus constitute a unique set of tubulin ligands which induce a novel mechanism of apoptosis.

  7. Severe NDE1-mediated microcephaly results from neural progenitor cell cycle arrests at multiple specific stages.

    Science.gov (United States)

    Doobin, David J; Kemal, Shahrnaz; Dantas, Tiago J; Vallee, Richard B

    2016-01-01

    Microcephaly is a cortical malformation disorder characterized by an abnormally small brain. Recent studies have revealed severe cases of microcephaly resulting from human mutations in the NDE1 gene, which is involved in the regulation of cytoplasmic dynein. Here using in utero electroporation of NDE1 short hairpin RNA (shRNA) in embryonic rat brains, we observe cell cycle arrest of proliferating neural progenitors at three distinct stages: during apical interkinetic nuclear migration, at the G2-to-M transition and in regulation of primary cilia at the G1-to-S transition. RNAi against the NDE1 paralogue NDEL1 has no such effects. However, NDEL1 overexpression can functionally compensate for NDE1, except at the G2-to-M transition, revealing a unique NDE1 role. In contrast, NDE1 and NDEL1 RNAi have comparable effects on postmitotic neuronal migration. These results reveal that the severity of NDE1-associated microcephaly results not from defects in mitosis, but rather the inability of neural progenitors to ever reach this stage. PMID:27553190

  8. Chamaejasmine Arrests Cell Cycle, Induces Apoptosis and Inhibits Nuclear NF-κB Translocation in the Human Breast Cancer Cell Line MDA-MB-231

    OpenAIRE

    Yuxian Bai; Guanglu Dong; Li Cai; Hongyang Yu; Tingting Zhang

    2013-01-01

    In this study, the anticancer activity of chamaejasmine was characterized in the human breast cancer cell line, MDA-MB-231. Cell viability and cell cycle distribution were determined by MTT assay and flow cytometry, respectively. Western blotting was performed to determine changes in levels of various proteins. Results showed that treatment with chamaejasmine (4–16 μM) inhibited cell proliferation, which correlated with G2/M phase arrest and apoptosis in MDA-MB-231 cells. C...

  9. Radon and radon daughter monitoring (including thoron daughter monitoring)

    International Nuclear Information System (INIS)

    Radon/radon daughter and thoron daughter measurement techniques are outlined. The necessary precautions and critical assessments of each method are also presented with a view to providing a better understanding of the various measurement methods

  10. Nucleolin down-regulation is involved in ADP-induced cell cycle arrest in S phase and cell apoptosis in vascular endothelial cells.

    Directory of Open Access Journals (Sweden)

    Wenmeng Wang

    Full Text Available High concentration of extracellular ADP has been reported to induce cell apoptosis, but the molecular mechanisms remain not fully elucidated. In this study, we found by serendipity that ADP treatment of human umbilical vein endothelial cells (HUVEC and human aortic endothelial cells (HAEC down-regulated the protein level of nucleolin in a dose- and time-dependent manner. ADP treatment did not decrease the transcript level of nucloelin, suggesting that ADP might induce nucleolin protein degradation. HUVEC and HAEC expressed ADP receptor P2Y13 receptor, but did not express P2Y1 or P2Y12 receptors. However, P2Y1, 12, 13 receptor antagonists MRS2179, PSB0739, MRS2211 did not inhibit ADP-induced down-regulation of nucleolin. Moreover, MRS2211 itself down-regulated nucleolin protein level. In addition, 2-MeSADP, an agonist for P2Y1, 12 and 13 receptors, did not down-regulate nucleolin protein. These results suggested that ADP-induced nucleolin down-regulation was not due to the activation of P2Y1, 12, or 13 receptors. We also found that ADP treatment induced cell cycle arrest in S phase, cell apoptosis and cell proliferation inhibition via nucleolin down-regulation. The over-expression of nucleolin by gene transfer partly reversed ADP-induced cell cycle arrest, cell apoptosis and cell proliferation inhibition. Furthermore, ADP sensitized HUVEC to cisplatin-induced cell death by the down-regulation of Bcl-2 expression. Taken together, we found, for the first time to our knowledge, a novel mechanism by which ADP regulates cell proliferation by induction of cell cycle arrest and cell apoptosis via targeting nucelolin.

  11. H4 histamine receptors mediate cell cycle arrest in growth factor-induced murine and human hematopoietic progenitor cells.

    Directory of Open Access Journals (Sweden)

    Anne-France Petit-Bertron

    Full Text Available The most recently characterized H4 histamine receptor (H4R is expressed preferentially in the bone marrow, raising the question of its role during hematopoiesis. Here we show that both murine and human progenitor cell populations express this receptor subtype on transcriptional and protein levels and respond to its agonists by reduced growth factor-induced cell cycle progression that leads to decreased myeloid, erythroid and lymphoid colony formation. H4R activation prevents the induction of cell cycle genes through a cAMP/PKA-dependent pathway that is not associated with apoptosis. It is mediated specifically through H4R signaling since gene silencing or treatment with selective antagonists restores normal cell cycle progression. The arrest of growth factor-induced G1/S transition protects murine and human progenitor cells from the toxicity of the cell cycle-dependent anticancer drug Ara-C in vitro and reduces aplasia in a murine model of chemotherapy. This first evidence for functional H4R expression in hematopoietic progenitors opens new therapeutic perspectives for alleviating hematotoxic side effects of antineoplastic drugs.

  12. Resveratrol oligomers isolated from Carex species inhibit growth of human colon tumorigenic cells mediated by cell cycle arrest.

    Science.gov (United States)

    González-Sarrías, Antonio; Gromek, Samantha; Niesen, Daniel; Seeram, Navindra P; Henry, Geneive E

    2011-08-24

    Research has shown that members of the Carex genus produce biologically active stilbenoids including resveratrol oligomers. This is of great interest to the nutraceutical industry given that resveratrol, a constituent of grape and red wine, has attracted immense research attention due to its potential human health benefits. In the current study, five resveratrol oligomers (isolated from Carex folliculata and Carex gynandra ), along with resveratrol, were evaluated for antiproliferative effects against human colon cancer (HCT-116, HT-29, Caco-2) and normal human colon (CCD-18Co) cells. The resveratrol oligomers included one dimer, two trimers, and two tetramers: pallidol (1); α-viniferin (2) and trans-miyabenol C (3); and kobophenols A (4) and B (5), respectively. Although not cytotoxic, the resveratrol oligomers (1-5), as well as resveratrol, inhibited growth of the human colon cancer cells. Among the six stilbenoids, α-viniferin (2) was most active against the colon cancer cells with IC(50) values of 6-32 μM (>2-fold compared to normal colon cells). Moreover, α-viniferin (at 20 μM) did not induce apoptosis but arrested cell cycle (in the S-phase) for the colon cancer but not the normal colon cells. This study adds to the growing body of knowledge supporting the anticancer effects of resveratrol and its oligomers. Furthermore, Carex species should be investigated for their nutraceutical potential given that they produce biologically active stilbenoids such as α-viniferin. PMID:21761862

  13. Daughters on Hunger Strike

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    Ann Wan-lih Chang

    2008-03-01

    Full Text Available This essay explores the embattled interactions between mothers and daughters in the stories by Edna O’Brien, Mary Lavin, Éilís Ní Dhuibhne and Mary Leland. This conflict involves an underlying distorted intimacy between women within a patriarchal Irish context. The daughter in the stories seeks to rebel against the ‘choking love’ of the tyrannical ‘patriarchal mother’ through a symbolic anorexia, in which the daughter rejects the mother’s food or the food associated with the mother. The mother is also shown to feel ambivalent and resistant towards the daughter’s attempt to break from her dependence upon the mother. The conflict and resistance between mothers and daughters in these stories can be evaluated against the framework of the patriarchal context in which women as mothers are silenced and made powerless in front of the ‘Father,’ and therefore, this resistance can be interpreted as a reaction to this patriarchal ideology and its framework in Irish society. The lost bond between older and younger women needs to be rediscovered and restored by a realisation of patriarchal ideology and furthermore, identification with female subjectivity. This identification between women seems to act as a source of redemption for women of different generations, which results in both liberating themselves from the patriarchal dogma.

  14. Live-Cell Imaging Visualizes Frequent Mitotic Skipping During Senescence-Like Growth Arrest in Mammary Carcinoma Cells Exposed to Ionizing Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, Masatoshi, E-mail: msuzuki@nagasaki-u.ac.jp [Department of Radiation Medical Sciences, Atomic Bomb Disease Institute, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki (Japan); Yamauchi, Motohiro; Oka, Yasuyoshi; Suzuki, Keiji; Yamashita, Shunichi [Department of Radiation Medical Sciences, Atomic Bomb Disease Institute, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki (Japan)

    2012-06-01

    Purpose: Senescence-like growth arrest in human solid carcinomas is now recognized as the major outcome of radiotherapy. This study was designed to analyze cell cycle during the process of senescence-like growth arrest in mammary carcinoma cells exposed to X-rays. Methods and Materials: Fluorescent ubiquitination-based cell cycle indicators were introduced into the human mammary carcinoma cell line MCF-7. Cell cycle was sequentially monitored by live-cell imaging for up to 5 days after exposure to 10 Gy of X-rays. Results: Live-cell imaging revealed that cell cycle transition from G2 to G1 phase without mitosis, so-called mitotic skipping, was observed in 17.1% and 69.8% of G1- and G2-irradiated cells, respectively. Entry to G1 phase was confirmed by the nuclear accumulation of mKO{sub 2}-hCdt1 as well as cyclin E, which was inversely correlated to the accumulation of G2-specific markers such as mAG-hGeminin and CENP-F. More than 90% of cells skipping mitosis were persistently arrested in G1 phase and showed positive staining for the senescent biochemical marker, which is senescence-associated ss-galactosidase, indicating induction of senescence-like growth arrest accompanied by mitotic skipping. While G2 irradiation with higher doses of X-rays induced mitotic skipping in approximately 80% of cells, transduction of short hairpin RNA (shRNA) for p53 significantly suppressed mitotic skipping, suggesting that ionizing radiation-induced mitotic skipping is associated with p53 function. Conclusions: The present study found the pathway of senescence-like growth arrest in G1 phase without mitotic entry following G2-irradiation.

  15. Live-Cell Imaging Visualizes Frequent Mitotic Skipping During Senescence-Like Growth Arrest in Mammary Carcinoma Cells Exposed to Ionizing Radiation

    International Nuclear Information System (INIS)

    Purpose: Senescence-like growth arrest in human solid carcinomas is now recognized as the major outcome of radiotherapy. This study was designed to analyze cell cycle during the process of senescence-like growth arrest in mammary carcinoma cells exposed to X-rays. Methods and Materials: Fluorescent ubiquitination-based cell cycle indicators were introduced into the human mammary carcinoma cell line MCF-7. Cell cycle was sequentially monitored by live-cell imaging for up to 5 days after exposure to 10 Gy of X-rays. Results: Live-cell imaging revealed that cell cycle transition from G2 to G1 phase without mitosis, so-called mitotic skipping, was observed in 17.1% and 69.8% of G1- and G2-irradiated cells, respectively. Entry to G1 phase was confirmed by the nuclear accumulation of mKO2-hCdt1 as well as cyclin E, which was inversely correlated to the accumulation of G2-specific markers such as mAG-hGeminin and CENP-F. More than 90% of cells skipping mitosis were persistently arrested in G1 phase and showed positive staining for the senescent biochemical marker, which is senescence-associated ß-galactosidase, indicating induction of senescence-like growth arrest accompanied by mitotic skipping. While G2 irradiation with higher doses of X-rays induced mitotic skipping in approximately 80% of cells, transduction of short hairpin RNA (shRNA) for p53 significantly suppressed mitotic skipping, suggesting that ionizing radiation-induced mitotic skipping is associated with p53 function. Conclusions: The present study found the pathway of senescence-like growth arrest in G1 phase without mitotic entry following G2-irradiation.

  16. Piperlongumine Suppresses Proliferation of Human Oral Squamous Cell Carcinoma through Cell Cycle Arrest, Apoptosis and Senescence

    OpenAIRE

    San-Yuan Chen; Geng-Hung Liu; Wen-Ying Chao; Chung-Sheng Shi; Ching-Yen Lin; Yun-Ping Lim; Chieh-Hsiang Lu; Peng-Yeh Lai; Hau-Ren Chen; Ying-Ray Lee

    2016-01-01

    Oral squamous cell carcinoma (OSCC), an aggressive cancer originating in the oral cavity, is one of the leading causes of cancer deaths in males worldwide. This study investigated the antitumor activity and mechanisms of piperlongumine (PL), a natural compound isolated from Piper longum L., in human OSCC cells. The effects of PL on cell proliferation, the cell cycle, apoptosis, senescence and reactive oxygen species (ROS) levels in human OSCC cells were investigated. PL effectively inhibited ...

  17. Palmitic Acid-Induced Neuron Cell Cycle G2/M Arrest and Endoplasmic Reticular Stress through Protein Palmitoylation in SH-SY5Y Human Neuroblastoma Cells

    Directory of Open Access Journals (Sweden)

    Yung-Hsuan Hsiao

    2014-11-01

    Full Text Available Obesity-related neurodegenerative diseases are associated with elevated saturated fatty acids (SFAs in the brain. An increase in SFAs, especially palmitic acid (PA, triggers neuron cell apoptosis, causing cognitive function to deteriorate. In the present study, we focused on the specific mechanism by which PA triggers SH-SY5Y neuron cell apoptosis. We found that PA induces significant neuron cell cycle arrest in the G2/M phase in SH-SY5Y cells. Our data further showed that G2/M arrest is involved in elevation of endoplasmic reticular (ER stress according to an increase in p-eukaryotic translation inhibition factor 2α, an ER stress marker. Chronic exposure to PA also accelerates beta-amyloid accumulation, a pathological characteristic of Alzheimer’s disease. Interestingly, SFA-induced ER stress, G2/M arrest and cell apoptosis were reversed by treatment with 2-bromopalmitate, a protein palmitoylation inhibitor. These findings suggest that protein palmitoylation plays a crucial role in SFA-induced neuron cell cycle G2/M arrest, ER stress and apoptosis; this provides a novel strategy for preventing SFA-induced neuron cell dysfunction.

  18. Germline stem cell arrest inhibits the collapse of somatic proteostasis early in Caenorhabditis elegans adulthood.

    Science.gov (United States)

    Shemesh, Netta; Shai, Nadav; Ben-Zvi, Anat

    2013-10-01

    All cells rely on highly conserved protein folding and clearance pathways to detect and resolve protein damage and to maintain protein homeostasis (proteostasis). Because age is associated with an imbalance in proteostasis, there is a need to understand how protein folding is regulated in a multicellular organism that undergoes aging. We have observed that the ability of Caenorhabditis elegans to maintain proteostasis declines sharply following the onset of oocyte biomass production, suggesting that a restricted protein folding capacity may be linked to the onset of reproduction. To test this hypothesis, we monitored the effects of different sterile mutations on the maintenance of proteostasis in the soma of C. elegans. We found that germline stem cell (GSC) arrest rescued protein quality control, resulting in maintenance of robust proteostasis in different somatic tissues of adult animals. We further demonstrated that GSC-dependent modulation of proteostasis requires several different signaling pathways, including hsf-1 and daf-16/kri-1/tcer-1, daf-12, daf-9, daf-36, nhr-80, and pha-4 that differentially modulate somatic quality control functions, such that each signaling pathway affects different aspects of proteostasis and cannot functionally complement the other pathways. We propose that the effect of GSCs on the collapse of proteostasis at the transition to adulthood is due to a switch mechanism that links GSC status with maintenance of somatic proteostasis via regulation of the expression and function of different quality control machineries and cellular stress responses that progressively lead to a decline in the maintenance of proteostasis in adulthood, thereby linking reproduction to the maintenance of the soma. PMID:23734734

  19. 3,3'-Diindolylmethane induces G1 arrest and apoptosis in human acute T-cell lymphoblastic leukemia cells.

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    Lyndsey E Shorey

    Full Text Available Certain bioactive food components, including indole-3-carbinol (I3C and 3,3'-diindolylmethane (DIM from cruciferous vegetables, have been shown to target cellular pathways regulating carcinogenesis. Previously, our laboratory showed that dietary I3C is an effective transplacental chemopreventive agent in a dibenzo[def,p]chrysene (DBC-dependent model of murine T-cell lymphoblastic lymphoma. The primary objective of the present study was to extend our chemoprevention studies in mice to an analogous human neoplasm in cell culture. Therefore, we tested the hypothesis that I3C or DIM may be chemotherapeutic in human T-cell acute lymphoblastic leukemia (T-ALL cells. Treatment of the T-ALL cell lines CCRF-CEM, CCRF-HSB2, SUP-T1 and Jurkat with DIM in vitro significantly reduced cell proliferation and viability at concentrations 8- to 25-fold lower than the parent compound I3C. DIM (7.5 µM arrested CEM and HSB2 cells at the G(1 phase of the cell cycle and 15 µM DIM significantly increased the percentage of apoptotic cells in all T-ALL lines. In CEM cells, DIM reduced protein expression of cyclin dependent kinases 4 and 6 (CDK4, CDK6 and D-type cyclin 3 (CCND3; DIM also significantly altered expression of eight transcripts related to human apoptosis (BCL2L10, CD40LG, HRK, TNF, TNFRSF1A, TNFRSF25, TNFSF8, TRAF4. Similar anticancer effects of DIM were observed in vivo. Dietary exposure to 100 ppm DIM significantly decreased the rate of growth of human CEM xenografts in immunodeficient SCID mice, reduced final tumor size by 44% and increased the apoptotic index compared to control-fed mice. Taken together, our results demonstrate a potential for therapeutic application of DIM in T-ALL.

  20. G2/M Cell Cycle Arrest and Tumor Selective Apoptosis of Acute Leukemia Cells by a Promising Benzophenone Thiosemicarbazone Compound.

    Science.gov (United States)

    Cabrera, Maia; Gomez, Natalia; Remes Lenicov, Federico; Echeverría, Emiliana; Shayo, Carina; Moglioni, Albertina; Fernández, Natalia; Davio, Carlos

    2015-01-01

    Anti-mitotic therapies have been considered a hallmark in strategies against abnormally proliferating cells. Focusing on the extensively studied family of thiosemicarbazone (TSC) compounds, we have previously identified 4,4'-dimethoxybenzophenone thiosemicarbazone (T44Bf) as a promising pharmacological compound in a panel of human leukemia cell lines (HL60, U937, KG1a and Jurkat). Present findings indicate that T44Bf-mediated antiproliferative effects are associated with a reversible chronic mitotic arrest caused by defects in chromosome alignment, followed by induced programmed cell death. Furthermore, T44Bf selectively induces apoptosis in leukemia cell lines when compared to normal peripheral blood mononuclear cells. The underlying mechanism of action involves the activation of the mitochondria signaling pathway, with loss of mitochondrial membrane potential and sustained phosphorylation of anti-apoptotic protein Bcl-xL as well as increased Bcl-2 (enhanced phosphorylated fraction) and pro-apoptotic protein Bad levels. In addition, ERK signaling pathway activation was found to be a requisite for T44Bf apoptotic activity. Our findings further describe a novel activity for a benzophenone thiosemicarbazone and propose T44Bf as a promising anti-mitotic prototype to develop chemotherapeutic agents to treat acute leukemia malignancies. PMID:26360247

  1. G2/M Cell Cycle Arrest and Tumor Selective Apoptosis of Acute Leukemia Cells by a Promising Benzophenone Thiosemicarbazone Compound.

    Directory of Open Access Journals (Sweden)

    Maia Cabrera

    Full Text Available Anti-mitotic therapies have been considered a hallmark in strategies against abnormally proliferating cells. Focusing on the extensively studied family of thiosemicarbazone (TSC compounds, we have previously identified 4,4'-dimethoxybenzophenone thiosemicarbazone (T44Bf as a promising pharmacological compound in a panel of human leukemia cell lines (HL60, U937, KG1a and Jurkat. Present findings indicate that T44Bf-mediated antiproliferative effects are associated with a reversible chronic mitotic arrest caused by defects in chromosome alignment, followed by induced programmed cell death. Furthermore, T44Bf selectively induces apoptosis in leukemia cell lines when compared to normal peripheral blood mononuclear cells. The underlying mechanism of action involves the activation of the mitochondria signaling pathway, with loss of mitochondrial membrane potential and sustained phosphorylation of anti-apoptotic protein Bcl-xL as well as increased Bcl-2 (enhanced phosphorylated fraction and pro-apoptotic protein Bad levels. In addition, ERK signaling pathway activation was found to be a requisite for T44Bf apoptotic activity. Our findings further describe a novel activity for a benzophenone thiosemicarbazone and propose T44Bf as a promising anti-mitotic prototype to develop chemotherapeutic agents to treat acute leukemia malignancies.

  2. Silencing of AP-4 inhibits proliferation, induces cell cycle arrest and promotes apoptosis in human lung cancer cells

    Science.gov (United States)

    HU, XUANYU; GUO, WEI; CHEN, SHANSHAN; XU, YIZHUO; LI, PING; WANG, HUAQI; CHU, HEYING; LI, JUAN; DU, YUWEN; CHEN, XIAONAN; ZHANG, GUOJUN; ZHAO, GUOQIANG

    2016-01-01

    Activating enhancer-binding protein (AP)-4 is a member of the basic helix-loop-helix transcription factors, and is involved in tumor biology. However, the role of AP-4 in human lung cancer remains to be fully elucidated. In the present study, the expression of AP-4 in human lung cancer tissues and cells was investigated by reverse transcription-quantitative polymerase chain reaction, and it was observed that the level of AP-4 was increased in tumor tissues and cells compared with their normal counterparts. AP-4 expression was knocked down by transfection with a specific small interfering RNA (siRNA) in lung cancer cells, and this indicated that siRNA-mediated silencing of AP-4 inhibited cell proliferation, arrested the cell cycle at the G0/G1 phase and induced apoptosis by modulating the expression of p21 and cyclin D1. The results of the present study suggest that AP-4 may be an oncoprotein that has a significant role in lung cancer, and that siRNA-mediated silencing of AP-4 may have therapeutic potential as a strategy for the treatment of lung cancer.

  3. Wogonin induced G1 cell cycle arrest by regulating Wnt/β-catenin signaling pathway and inactivating CDK8 in human colorectal cancer carcinoma cells

    International Nuclear Information System (INIS)

    Highlights: • Wogonin inhibited HCT116 cells growth and arrested at G1 phase of the cell cycle. • Wogonin down-regulated the canonical Wnt/β-catenin signaling pathway. • Wogonin interfered in the combination of β-catenin and TCF/Lef. • Wogonin limited the kinase activity of CDK8. - Abstract: Wogonin, a naturally occurring mono-flavonoid, has been reported to have tumor therapeutic potential and good selectivity both in vitro and in vivo. Herein, we investigated the anti-proliferation effects and associated mechanisms of wogonin in human colorectal cancer in vitro. The flow-cytometric analysis showed that wogonin induced a G1 phase cell cycle arrest in HCT116 cells in a concentration- and time-dependent manner. Meanwhile, the cell cycle-related proteins, such as cyclin A, E, D1, and CDK2, 4 were down-regulated in wogonin-induced G1 cell cycle arrest. Furthermore, we showed that the anti-proliferation and G1 arrest effect of wogonin on HCT116 cells was associated with deregulation of Wnt/β-catenin signaling pathway. Wogonin-treated cells showed decreased intracellular levels of Wnt proteins, and activated degradation complex to phosphorylated and targeted β-catenin for proteasomal degradation. Wogonin inhibited β-catenin-mediated transcription by interfering in the transcriptional activity of TCF/Lef, and repressing the kinase activity of CDK8 which has been considered as an oncogene involving in the development of colorectal cancers. Moreover, CDK8 siRNA-transfected HCT116 cells showed similar results to wogonin treated cells. Thus, our data suggested that wogonin induced anti-proliferation and G1 arrest via Wnt/β-catenin signaling pathway and it can be developed as a therapeutic agent against human colorectal cancer

  4. Salinomycin sensitizes antimitotic drugs-treated cancer cells by increasing apoptosis via the prevention of G2 arrest

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ju-Hwa; Yoo, Hye-In; Kang, Han Sung; Ro, Jungsil [Research Institute, National Cancer Center, Ilsan-gu, Goyang-si, Gyeonggi-do (Korea, Republic of); Yoon, Sungpil, E-mail: yoons@ncc.re.kr [Research Institute, National Cancer Center, Ilsan-gu, Goyang-si, Gyeonggi-do (Korea, Republic of)

    2012-02-03

    Highlights: Black-Right-Pointing-Pointer Sal sensitizes antimitotic drugs-treated cancer cells. Black-Right-Pointing-Pointer Sal sensitizes them by prevention of G2 arrest and reduced cyclin D1 levels. Black-Right-Pointing-Pointer Sal also sensitizes them by increasing DNA damage and reducing p21 level. Black-Right-Pointing-Pointer A low concentration of Sal effectively sensitized the cancer cells to antimitotic drugs. -- Abstract: Here, we investigated whether Sal could sensitize cancer cells to antimitotic drugs. We demonstrated that Sal sensitized paclitaxcel (PAC)-, docetaxcel (DOC)-, vinblastin (VIN)-, or colchicine (COL)-treated cancer cell lines, suggesting that Sal has the ability to sensitize the cells to any form of microtubule-targeting drugs. Sensitization to the antimitotic drugs could be achieved with very low concentrations of Sal, suggesting that there is a possibility to minimize Sal toxicity associated with human cancer patient treatments. Sensitization by Sal increased apoptosis, which was observed by C-PARP production. Sal sensitized the cancer cells to antimitotic drugs by preventing G2 arrest, suggesting that Sal contributes to the induction of mitotic catastrophe. Sal generally reduced cyclin D1 levels in PAC-, DOC-, and VIN-treated cells. In addition, Sal treatment increased pH2AX levels and reduced p21 levels in antimitotic drugs-treated cells. These observations suggest that the mechanisms underlying Sal sensitization to DNA-damaging compounds, radiation, and microtubule-targeting drugs are similar. Our data demonstrated that Sal sensitizes cancer cells to antimitotic drugs by increasing apoptosis through the prevention of G2 arrest via conserved Sal-sensitization mechanisms. These results may contribute to the development of Sal-based chemotherapy for cancer patients treated with antimitotic drugs.

  5. Effects of HIV-1 Tat protein on expression of cell cycle-related genes and radiation-induced cell cycle arrest

    International Nuclear Information System (INIS)

    Objective: To explore effects of HIV-1 Tat protein on the expression of cell cycle-related genes and cell cycle arrest induced by ionizing radiation. Methods: A human rhabdomyosarcoma cell line TE671 and TT2 cells generated from TE671 cells by transfecting with tat gene of the HIV-1 strain were employed. Microarray, which contained the oligonucleotide probes corresponding to 102 human DNA damage response related genes, was used to analyze transcriptional changes. Cell cycle changes were analyzed by flow cytometry. Results: Microarray assay demonstrated that cell cycle-related genes Cdc20, Cdc25C, KIF2C, CTS1 and Wee1 were down-regulated in Tat-expressing TT2 cells. Tat-expressing cells exhibited a noticeable delay of the initiation and elimination of radiation-induced G2/M arrest and a prolonged S phase arrest as compared with parental cells. Moreover, overexpression of cyclinB1 was also observed in Tat-expressing TT2 cells. Conclusion: Dysregulated cell cycle checkpoint in Tat-expressing cells can provide new information for understanding the radiation responsiveness of AIDS patients with cancer to radiotherapy. (authors)

  6. Effects of gamma-radiation on cell growth, cycle arrest, death, and superoxide dismutase expression by DU 145 human prostate cancer cells

    Directory of Open Access Journals (Sweden)

    Vucic V.

    2006-01-01

    Full Text Available Gamma-irradiation (gamma-IR is extensively used in the treatment of hormone-resistant prostate carcinoma. The objective of the present study was to investigate the effects of 60Co gamma-IR on the growth, cell cycle arrest and cell death of the human prostate cancer cell line DU 145. The viability of DU 145 cells was measured by the Trypan blue exclusion assay and the 3(4,5-dimethylthiazol-2-yl-2,5,diphenyltetrazolium bromide test. Bromodeoxyuridine incorporation was used for the determination of cell proliferation. Cell cycle arrest and cell death were analyzed by flow cytometry. Superoxide dismutase (SOD, specifically CuZnSOD and MnSOD protein expression, after 10 Gy gamma-IR, was determined by Western immunoblotting analysis. gamma-IR treatment had a significant (P < 0.001 antiproliferative and cytotoxic effect on DU 145 cells. Both effects were time and dose dependent. Also, the dose of gamma-IR which inhibited DNA synthesis and cell proliferation by 50% was 9.7 Gy. Furthermore, gamma-IR induced cell cycle arrest in the G2/M phase and the percentage of cells in the G2/M phase was increased from 15% (control to 49% (IR cells, with a nonsignificant induction of apoptosis. Treatment with 10 Gy gamma-IR for 24, 48, and 72 h stimulated CuZnSOD and MnSOD protein expression in a time-dependent manner, approximately by 3- to 3.5-fold. These data suggest that CuZnSOD and MnSOD enzymes may play an important role in the gamma-IR-induced changes in DU 145 cell growth, cell cycle arrest and cell death.

  7. Daily Arrests

    Data.gov (United States)

    Montgomery County of Maryland — This dataset provides the public with arrest information from the Montgomery County Central Processing Unit (CPU) systems. The data presented is derived from every...

  8. Aristolochic acid-induced apoptosis and G2 cell cycle arrest depends on ROS generation and MAP kinases activation.

    Science.gov (United States)

    Romanov, Victor; Whyard, Terry C; Waltzer, Wayne C; Grollman, Arthur P; Rosenquist, Thomas

    2015-01-01

    Ingestion of aristolochic acids (AAs) contained in herbal remedies results in a renal disease and, frequently, urothelial malignancy. The genotoxicity of AA in renal cells, including mutagenic DNA adducts formation, is well documented. However, the mechanisms of AA-induced tubular atrophy and renal fibrosis are largely unknown. To better elucidate some aspects of this process, we studied cell cycle distribution and cell survival of renal epithelial cells treated with AAI at low and high doses. A low dose of AA induces cell cycle arrest in G2/M phase via activation of DNA damage checkpoint pathway ATM-Chk2-p53-p21. DNA damage signaling pathway is activated more likely via increased production of reactive oxygen species (ROS) caused by AA treatment then via DNA damage induced directly by AA. Higher AA concentration induced cell death partly via apoptosis. Since mitogen-activated protein kinases play an important role in cell survival, death and cell cycle progression, we assayed their function in AA-treated renal tubular epithelial cells. ERK1/2 and p38 but not JNK were activated in cells treated with AA. In addition, pharmacological inhibition of ERK1/2 and p38 as well as suppression of ROS generation with N-acetyl-L-cysteine resulted in the partial relief of cells from G2/M checkpoint and a decline of apoptosis level. Cell cycle arrest may be a mechanism for DNA repair, cell survival and reprogramming of epithelial cells to the fibroblast type. An apoptosis of renal epithelial cells at higher AA dose might be necessary to provide space for newly reprogrammed fibrotic cells. PMID:24792323

  9. Grifola frondosa Glycoprotein GFG-3a Arrests S phase, Alters Proteome, and Induces Apoptosis in Human Gastric Cancer Cells.

    Science.gov (United States)

    Cui, Fengjie; Zan, Xinyi; Li, Yunhong; Sun, Wenjing; Yang, Yan; Ping, Lifeng

    2016-01-01

    GFG-3a is a novel glycoprotein previously purified from the fermented mycelia of Grifola frondosa with novel sugar compositions and protein sequencing. The present study aims to investigate its effects on the cell cycle, differential proteins expression, and apoptosis of human gastric cancer SGC-7901 cells. Our findings revealed that GFG-3a induced the cell apoptosis and arrested cell cycle at S phase. GFG-3a treatment resulted in the differential expression of 21 proteins in SGC-7901 cells by upregulating 10 proteins including RBBP4 associated with cell cycle arrest and downregulating 11 proteins including RUVBL1, NPM, HSP90AB1, and GRP78 involved in apoptosis and stress response. qRT-PCR and Western blot analysis also suggested that GFG-3a could increase the expressions of Caspase-8/-3, p53, Bax, and Bad while decrease the expressions of Bcl2, Bcl-xl, PI3K, and Akt1. These results indicated that the stress response, p53-dependent mitochondrial-mediated, Caspase-8/-3-dependent, and PI3k/Akt pathways were involved in the GFG-3a-induced apoptosis process in SGC-7901 cells. These findings might provide a basis to prevent or treat human gastric cancer with GFG-3a and understand the tumor-inhibitory molecular mechanisms of mushroom glycoproteins. PMID:27040446

  10. Synthesis of hybrid 4-deoxypodophyllotoxin-5-fluorouracil compounds that inhibit cellular migration and induce cell cycle arrest.

    Science.gov (United States)

    Guan, Xiao-Wen; Xu, Xiao-Hui; Feng, Shi-Liang; Tang, Zhen-Bo; Chen, Shi-Wu; Hui, Ling

    2016-03-15

    A series of deoxypodophyllotoxin-5-fluorouracil hybrid compounds were synthesized, and their cytotoxic activity was evaluated using four human cancer cell lines (HeLa, A549, HCT-8, and HepG2) and the human normal cell line WI-38. The synthesized compounds exhibited greater cytotoxic activity in tumor cells and reduced toxicity in the normal cell line compared with the anticancer drug VP-16 and 5-FU. Additionally, the most potent of these compounds-4'-O-demethyl-4-deoxypodophyllotoxin-4'-yl 4-((6-(2-(5-fluorouracil-yl) acetamido) hexyl) amino)-4-oxobutanoate (compound 22)-induced cell-cycle arrest in the G2/M phase by regulating levels of cdc2, cyclinB1, and p-cdc2 in A549 cells. Furthermore, compound 22 may inhibited the migration of A549 cells via down-regulation of MMP-9 and up-regulation of TIMP-1. PMID:26873416

  11. Daughter cyst sign

    OpenAIRE

    Randazzo, William Thoburn; Franco, Arie; Hoossainy, Saudiqa; Lewis, Kristopher Neal

    2012-01-01

    The daughter cyst sign is a specific indicator of an uncomplicated ovarian cyst and pathologically represents a stimulated ovarian follicle. This finding must be differentiated from an ectopic pregnancy in a patient who has the potential to become pregnant. We report an uncomplicated ovarian cyst in a 3-year-old female with McCune-Albright syndrome and precocious puberty mimicking an ectopic pregnancy.

  12. Inhibitive effect of 3-bromopyruvic acid on human breast cancer MCF-7 cells involves cell cycle arrest and apoptotic induction

    Institute of Scientific and Technical Information of China (English)

    LIU Xiao-hong; ZHENG Xue-fang; WANG Yong-li

    2009-01-01

    Background Breast cancer is one of the most common malignancies in women and is highly resistant to chemotherapy. Due to its high tumour selectivity, 3-bromopyruvic acid (3-BrPA), a well-known inhibitor of energy metabolism has been proposed as a specific anticancer agent. The present study determined the effect of 3-BrPA on proliferation, cell cycle and apoptosis in the human breast cancer MCF-7 cell line and other antitumour mechanisms. Methods MCF-7 cells were treated with various concentrations of 3-BrPA for 1-4 days, and cell growth was measured by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide assay. Marked morphological changes in MCF-7 cells after treatment with 3-BrPA were observed using transmission electron microscopy. The distributions of the cell cycle and apoptosis were analyzed by flow cytometry. Immunohistochemistry was used to indicate the changes in the expression of Bcl-2, c-Myc, and mutant p53. Results 3-BrPA (25 μg/ml) significantly inhibited the proliferation of MCF-7 cells in a time-dependent manner. The MCF-7 cells exposed to 3-BrPA showed the typical morphological characteristics of apoptosis, including karyopycnosis, nuclear condensation and oversize cytoplasmic particles. In addition, flow cytometric assay also showed more apoptotic cells after 3-BrPA stimulation. The cells at the GO and G1 phases were dramatically decreased while cells at the S and G2/M phases were increased in response to 3-BrPA treatment after 48 hours. Furthermore, 3-BrPA stimulation decreased the expressions of Bcl-2, c-Myc and mutant p53, which were strongly associated with the programmed cell death signal transduction pathway. Conclusion 3-BrPA inhibits proliferation, induces S phase and G2/M phase arrest, and promotes apoptosis in MCF-7 cells, which processes might be mediated by the downregulation of the expressions of Bcl-2, c-Myc and mutant p53.

  13. Anti-Tumor Effect of Rutin on Human Neuroblastoma Cell Lines through Inducing G2/M Cell Cycle Arrest and Promoting Apoptosis

    OpenAIRE

    Hongyan Chen; Qing Miao; Miao Geng; Jing Liu; Yazhuo Hu; Lei Tian; Jingkun Pan; Yi Yang

    2013-01-01

    Aims. To further investigate the antineuroblastoma effect of rutin which is a type of flavonoid. Methods. The antiproliferation of rutin in human neuroblastoma cells LAN-5 were detected by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Chemotaxis of LAN-5 cells was assessed using transwell migration chambers and scratch wound migration assay. The cell cycle arrest and apoptosis in a dose-dependent manner was measured by flow cytometric and fluorescent microscopy ana...

  14. Induction of G1-phase cell cycle arrest and apoptosis pathway in MDA-MB-231 human breast cancer cells by sulfated polysaccharide extracted from Laurencia papillosa

    OpenAIRE

    Murad, Hossam; Hawat, Mohammad; Ekhtiar, Adnan; ALJAPAWE, ABDULMUNIM; Abbas, Assef; Darwish, Hussein; Sbenati, Oula; Ghannam, Ahmed

    2016-01-01

    Background Marine algae consumption is linked to law cancer incidences in countries that traditionally consume marine products. Hence, Phytochemicals are considered as potential chemo-preventive and chemotherapeutic agents against cancer. We investigated the effects of the algal sulfated polysaccharide extract (ASPE) from the red marine alga L. papillosa on MDA-MB-231 human breast cancer cell line. Methods Flow cytometry analysis was performed to study the cell viability, cell cycle arrest an...

  15. Nox2 regulates endothelial cell cycle arrest and apoptosis via p21cip1 and p53

    OpenAIRE

    Li, Jian-Mei; Fan, Lampson M; George, Vinoj T.; Brooks, Gavin

    2007-01-01

    Endothelial cells (EC) express constitutively two major isoforms (Nox2 and Nox4) of the catalytic subunit of NADPH oxidase, which is a major source of endothelial reactive oxygen species. However, the individual roles of these Noxes in endothelial function remain unclear. We have investigated the role of Nox2 in nutrient deprivation-induced cell cycle arrest and apoptosis. In proliferating human dermal microvascular EC, Nox2 mRNA expression was low relative to Nox4 (Nox2:Nox4 ~1:13), but was ...

  16. X-ray induction of 6-thioguanine-resistant mutants in division arrested, G0/G1 phase Chinese hamster ovary cells

    International Nuclear Information System (INIS)

    The cytotoxic and mutagenic effect of X-irradiation was determined with Chinese hamster ovary cells arrested in the G0/G1 phase of the cell cycle through 9 days incubation in serum-free medium. In comparison with exponential phase cultures, the arrested cells showed increased cytotoxicity and mutation induction over the dose range of 50-800 rad. Exponential cultures showed a linear mutant frequency-survival relationship while the arrested cells showed a biphasic linear relationship. A post irradiation holding period 24 h does not result in any change in the mutant frequency. The increased sensitivity of the arrested cells to the mutagenic effects of X-rays appears to be a cell-cycle phase phenomenon. Upon readdition of serum, the arrested cells re-enter the cell cycle in a synchronous manner, reaching S phase at 10-12 h. Cells irradiated at 5 h after serum addition, i.e. in G1, show a similar dose response for mutant frequency, while those irradiated at 10 h or later, i.e. in late G1, S or G2, show lower mutation induction. These observations are consistent with a chromosome interchange mechanism of mutation induction by X-rays, possibly through interactions between repairing regions of the DNA. Irradiation of cells in the G0/G1 phase allow more time for such interactions in the absence of semiconservative DNA replication. (orig.)

  17. The role of reactive oxygen species (ROS) production on diallyl disulfide (DADS) induced apoptosis and cell cycle arrest in human A549 lung carcinoma cells

    Energy Technology Data Exchange (ETDEWEB)

    Wu Xinjiang [Institute of Indoor and Environmental Toxicology, Faculty of Medicine, Justus-Liebig-University of Giessen, Aulweg 123, D-35385 Giessen (Germany); Kassie, Fekadu [Institute of Indoor and Environmental Toxicology, Faculty of Medicine, Justus-Liebig-University of Giessen, Aulweg 123, D-35385 Giessen (Germany); Mersch-Sundermann, Volker [Institute of Indoor and Environmental Toxicology, Faculty of Medicine, Justus-Liebig-University of Giessen, Aulweg 123, D-35385 Giessen (Germany)]. E-mail: Volker.mersch-sundermann@uniklinikum-giessen.de

    2005-11-11

    Diallyl disulfide (DADS), an oil soluble constituent of garlic (Allium sativum), has been reported to cause antimutagentic and anticarcinogenic effects in vitro and in vivo by modulating phases I and II enzyme activities. In recent years, several studies suggested that the chemopreventive effects of DADS can also be attributed to induction of cell cycle arrest and apoptosis in cancer cells. In the present study, we reported that DADS-induced cell cycle arrest at G2/M and apoptosis in human A549 lung cancer cells in a time- and dose-dependent manner. Additionally, a significant increase of intracellular reactive oxygen species (ROS) was induced in A549 cells less than 0.5 h after DADS treatment, indicating that ROS may be an early event in DADS-modulated apoptosis. Treatment of A549 cells with N-acetyl cysteine (NAC) completely abrogated DADS-induced cell cycle arrest and apoptosis. The result indicated that oxidative stress modulates cell proliferation and cell death induced by DADS.

  18. The role of reactive oxygen species (ROS) production on diallyl disulfide (DADS) induced apoptosis and cell cycle arrest in human A549 lung carcinoma cells

    International Nuclear Information System (INIS)

    Diallyl disulfide (DADS), an oil soluble constituent of garlic (Allium sativum), has been reported to cause antimutagentic and anticarcinogenic effects in vitro and in vivo by modulating phases I and II enzyme activities. In recent years, several studies suggested that the chemopreventive effects of DADS can also be attributed to induction of cell cycle arrest and apoptosis in cancer cells. In the present study, we reported that DADS-induced cell cycle arrest at G2/M and apoptosis in human A549 lung cancer cells in a time- and dose-dependent manner. Additionally, a significant increase of intracellular reactive oxygen species (ROS) was induced in A549 cells less than 0.5 h after DADS treatment, indicating that ROS may be an early event in DADS-modulated apoptosis. Treatment of A549 cells with N-acetyl cysteine (NAC) completely abrogated DADS-induced cell cycle arrest and apoptosis. The result indicated that oxidative stress modulates cell proliferation and cell death induced by DADS

  19. ATM/ATR-related checkpoint signals mediate arsenite-induced G{sub 2}/M arrest in primary aortic endothelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Tsou, Tsui-Chun; Tsai, Feng-Yuan; Yeh, Szu-Ching; Chang, Louis W. [National Health Research Institutes, Division of Environmental Health and Occupational Medicine, Miaoli County (Taiwan)

    2006-12-15

    Epidemiological studies have demonstrated a high association of inorganic arsenic exposure with vascular disease. Our recent in vitro studies have linked this vascular damage to vascular endothelial dysfunction induced by arsenic exposure. However, cell-cycle arrest induced by arsenic and its involvement in vascular dysfunction remain to be clarified. In this study, we employed primary porcine aortic endothelial cells to investigate regulatory mechanisms of G{sub 2}/M phase arrest induced by arsenite. Our study revealed that lower concentrations of arsenite (1 and 3 {mu}M) increased cell proliferation, whereas higher concentrations of arsenite (10, 20, and 30 {mu}M) inhibited cell proliferation together with correlated increases in G{sub 2}/M phase arrest. We found that this arsenite-induced G{sub 2}/M phase arrest was accompanied by accumulation and/or phosphorylation of checkpoint-related molecules, including p53, Cdc25B, Cdc25C, and securin. Inhibition of activations of these checkpoint-related molecules by caffeine significantly attenuated the 30-{mu}M arsenite-induced G{sub 2}/M phase arrest by 93%. Our data suggest that the DNA damage responsive kinases ATM (ataxia-telangiectasia mutated) and ATR (ATM and Rad3-related) play critical roles in arsenite-induced G{sub 2}/M phase arrest in aortic endothelial cells possibly via regulation of checkpoint-related signaling molecules including p53, Cdc25B, Cdc25C, and securin. (orig.)

  20. 5-(2-Carboxyethenyl) isatin derivative induces G2/M cell cycle arrest and apoptosis in human leukemia K562 cells

    International Nuclear Information System (INIS)

    Highlights: • 5-(2-Carboxyethenyl) isatin derivative (HKL 2H) inhibited K562’s proliferation. • HKL 2H caused the morphology change of G2/M phase arrest and typical apoptosis. • HKL 2H induced G2/M cell cycle phase arrest in K562 cells. • HKL 2H induced apoptosis in K562 cells through the mitochondrial pathway. - Abstract: Our previous study successfully identified that the novel isatin derivative (E)-methyl 3-(1-(4-methoxybenzyl)-2,3-dioxoindolin-5-yl) acrylate (HKL 2H) acts as an anticancer agent at an inhibitory concentration (IC50) level of 3 nM. In this study, the molecular mechanism how HKL 2H induces cytotoxic activity in the human chronic myelogenous leukemia K562 cells was investigated. Flow cytometric analysis showed that the cells were arrested in the G2/M phase and accumulated subsequently in the sub-G1 phase in the presence of HKL 2H. HKL 2H treatment down-regulated the expressions of CDK1 and cyclin B but up-regulated the level of phosphorylated CDK1. Annexin-V staining and the classic DNA ladder studies showed that HKL 2H induced the apoptosis of K562 cells. Our study further showed that HKL 2H treatment caused the dissipation of mitochondrial membrane potential, activated caspase-3 and lowered the Bcl-2/Bax ratio in K562 cells, suggesting that the HKL 2H-causing programmed cell death of K562 cells was caused via the mitochondrial apoptotic pathway. Taken together, our data demonstrated that HKL 2H, a 5-(2-carboxyethenyl) isatin derivative, notably induces G2/M cell cycle arrest and mitochondrial-mediated apoptosis in K562 cells, indicating that this compound could be a promising anticancer candidate for further investigation

  1. 5-(2-Carboxyethenyl) isatin derivative induces G{sub 2}/M cell cycle arrest and apoptosis in human leukemia K562 cells

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Yao; Zhao, Hong-Ye; Han, Kai-Lin; Yang, Yao; Song, Bin-Bin; Guo, Qian-Nan [Key Laboratory of Industrial Microbiology, Ministry of Education, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457 (China); Tianjin Key Laboratory of Industry Microbiology, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457 (China); Fan, Zhen-Chuan [Key Laboratory of Food Nutrition and Safety (Tianjin University of Science and Technology), Ministry of Education, Tianjin 300457 (China); Obesita and Algaegen LLC, College Station, TX 77845 (United States); Zhang, Yong-Min [Université Pierre et Marie Curie-Paris 6, Institut Parisien de Chimie Moléculaire UMR CNRS 8232, 4 Place Jussieu, 75005 Paris (France); Teng, Yu-Ou, E-mail: tyo201485@tust.edu.cn [Key Laboratory of Industrial Microbiology, Ministry of Education, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457 (China); Tianjin Key Laboratory of Industry Microbiology, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457 (China); Yu, Peng, E-mail: yupeng@tust.edu.cn [Key Laboratory of Industrial Microbiology, Ministry of Education, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457 (China); Tianjin Key Laboratory of Industry Microbiology, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457 (China)

    2014-08-08

    Highlights: • 5-(2-Carboxyethenyl) isatin derivative (HKL 2H) inhibited K562’s proliferation. • HKL 2H caused the morphology change of G{sub 2}/M phase arrest and typical apoptosis. • HKL 2H induced G2/M cell cycle phase arrest in K562 cells. • HKL 2H induced apoptosis in K562 cells through the mitochondrial pathway. - Abstract: Our previous study successfully identified that the novel isatin derivative (E)-methyl 3-(1-(4-methoxybenzyl)-2,3-dioxoindolin-5-yl) acrylate (HKL 2H) acts as an anticancer agent at an inhibitory concentration (IC{sub 50}) level of 3 nM. In this study, the molecular mechanism how HKL 2H induces cytotoxic activity in the human chronic myelogenous leukemia K562 cells was investigated. Flow cytometric analysis showed that the cells were arrested in the G{sub 2}/M phase and accumulated subsequently in the sub-G{sub 1} phase in the presence of HKL 2H. HKL 2H treatment down-regulated the expressions of CDK1 and cyclin B but up-regulated the level of phosphorylated CDK1. Annexin-V staining and the classic DNA ladder studies showed that HKL 2H induced the apoptosis of K562 cells. Our study further showed that HKL 2H treatment caused the dissipation of mitochondrial membrane potential, activated caspase-3 and lowered the Bcl-2/Bax ratio in K562 cells, suggesting that the HKL 2H-causing programmed cell death of K562 cells was caused via the mitochondrial apoptotic pathway. Taken together, our data demonstrated that HKL 2H, a 5-(2-carboxyethenyl) isatin derivative, notably induces G{sub 2}/M cell cycle arrest and mitochondrial-mediated apoptosis in K562 cells, indicating that this compound could be a promising anticancer candidate for further investigation.

  2. Hedyotis diffusa Willd extract inhibits HT-29 cell proliferation via cell cycle arrest.

    Science.gov (United States)

    Lin, Minghe; Lin, Jiumao; Wei, Lihui; Xu, Wei; Hong, Zhenfeng; Cai, Qiaoyan; Peng, Jun; Zhu, Dezeng

    2012-08-01

    Hedyotis diffusa Willd (HDW) has long been used as an important component in several Chinese medicine formulae to clinically treat various types of cancer, including colorectal cancer (CRC). Previously, we reported that HDW inhibits CRC growth via the induction of cancer cell apoptosis and the inhibition of tumor angiogenesis. In the present study, to further elucidate the mechanism of HDW-mediated antitumor activity, we investigated the effect of HDW ethanol extract (EEHDW) on the proliferation of HT-29 human colon carcinoma cells. We found that EEHDW reduced HT-29 cell viability and survival in a dose- and time-dependent manner. We also observed that EEHDW treatment blocked the cell cycle, preventing G1 to S progression, and reduced mRNA expression of pro-proliferative PCNA, Cyclin D1 and CDK4, but increased that of anti-proliferative p21. Our findings suggest that Hedyotis diffusa Willd may be an effective treatment for CRC via the suppression of cancer cell proliferation. PMID:23139718

  3. Honokiol arrests cell cycle, induces apoptosis, and potentiates the cytotoxic effect of gemcitabine in human pancreatic cancer cells.

    Directory of Open Access Journals (Sweden)

    Sumit Arora

    Full Text Available Survival rates for patients with pancreatic cancer are extremely poor due to its asymptomatic progression to advanced and metastatic stage for which current therapies remain largely ineffective. Therefore, novel therapeutic agents and treatment approaches are desired to improve the clinical outcome. In this study, we determined the effects of honokiol, a biologically active constituent of oriental medicinal herb Magnolia officinalis/grandiflora, on two pancreatic cancer cell lines, MiaPaCa and Panc1, alone and in combination with the standard chemotherapeutic drug, gemcitabine. Honokiol exerted growth inhibitory effects on both the pancreatic cancer cell lines by causing cell cycle arrest at G₁ phase and induction of apoptosis. At the molecular level, honokiol markedly decreased the expression of cyclins (D1 and E and cyclin-dependent kinases (Cdk2 and Cdk4, and caused an increase in Cdk inhibitors, p21 and p27. Furthermore, honokiol treatment led to augmentation of Bax/Bcl-2 and Bax/Bcl-xL ratios to favor apoptosis in pancreatic cancer cells. These changes were accompanied by enhanced cytoplasmic accumulation of NF-κB with a concomitant decrease in nuclear fraction and reduced transcriptional activity of NF-κB responsive promoter. This was associated with decreased phosphorylation of inhibitor of kappa B alpha (IκB-α causing its stabilization and thus increased cellular levels. Importantly, honokiol also potentiated the cytotoxic effects of gemcitabine, in part, by restricting the gemcitabine-induced nuclear accumulation of NF-κB in the treated pancreatic cancer cell lines. Altogether, these findings demonstrate, for the first time, the growth inhibitory effects of honokiol in pancreatic cancer and indicate its potential usefulness as a novel natural agent in prevention and therapy.

  4. Brassinosteroids cause cell cycle arrest and apoptosis of human breast cancer cells

    Czech Academy of Sciences Publication Activity Database

    Steigerová, J.; Oklešťková, Jana; Levková, M.; Rárová, Lucie; Kolář, Z.; Strnad, Miroslav

    2010-01-01

    Roč. 188, č. 3 (2010), s. 487-496. ISSN 0009-2797 R&D Projects: GA ČR GA301/08/1649 Institutional research plan: CEZ:AV0Z50380511 Keywords : Brassinosteroids * cause * cell Subject RIV: FD - Oncology ; Hematology Impact factor: 2.832, year: 2010

  5. Developmental arrest of germ cells in the pathogenesis of germ cell neoplasia

    DEFF Research Database (Denmark)

    Rajpert-De Meyts, E; Jørgensen, N; Brøndum-Nielsen, K;

    1998-01-01

    Clinical observations and epidemiological evidence suggest that important aetiopathological events that cause neoplastic transformation of the male germ cell may occur in fetal life or early infancy. The incidence of germ cell neoplasia is high in individuals with various disorders of gonadal...... development and sexual differentiation, such as gonadal dysgenesis or androgen insensitivity syndrome. Increased risk has also been noted in individuals with trisomy 21, idiopathic infertility and low birth weight. Infertility is sometimes associated with small aberrations of sex chromosomes (e.g. low...... frequency mosaicism XY/XO) which can also be found in patients with testicular cancer. The variety of conditions that predispose to testicular neoplasia and the rise in its incidence in many countries speaks for the influence of environmental factors which may affect genetically predisposed individuals. We...

  6. Hedyotis diffusa Willd extract inhibits HT-29 cell proliferation via cell cycle arrest

    OpenAIRE

    Lin, Minghe; LIN, JIUMAO; Wei, Lihui; Xu, Wei; HONG, ZHENFENG; Cai, Qiaoyan; Peng, Jun; ZHU, DEZENG

    2012-01-01

    Hedyotis diffusa Willd (HDW) has long been used as an important component in several Chinese medicine formulae to clinically treat various types of cancer, including colorectal cancer (CRC). Previously, we reported that HDW inhibits CRC growth via the induction of cancer cell apoptosis and the inhibition of tumor angiogenesis. In the present study, to further elucidate the mechanism of HDW-mediated antitumor activity, we investigated the effect of HDW ethanol extract (EEHDW) on the proliferat...

  7. Prolonged mitotic arrest induces a caspase-dependent DNA damage response at telomeres that determines cell survival.

    Science.gov (United States)

    Hain, Karolina O; Colin, Didier J; Rastogi, Shubhra; Allan, Lindsey A; Clarke, Paul R

    2016-01-01

    A delay in the completion of metaphase induces a stress response that inhibits further cell proliferation or induces apoptosis. This response is thought to protect against genomic instability and is important for the effects of anti-mitotic cancer drugs. Here, we show that mitotic arrest induces a caspase-dependent DNA damage response (DDR) at telomeres in non-apoptotic cells. This pathway is under the control of Mcl-1 and other Bcl-2 family proteins and requires caspase-9, caspase-3/7 and the endonuclease CAD/DFF40. The gradual caspase-dependent loss of the shelterin complex protein TRF2 from telomeres promotes a DDR that involves DNA-dependent protein kinase (DNA-PK). Suppression of mitotic telomere damage by enhanced expression of TRF2, or the inhibition of either caspase-3/7 or DNA-PK during mitotic arrest, promotes subsequent cell survival. Thus, we demonstrate that mitotic stress is characterised by the sub-apoptotic activation of a classical caspase pathway, which promotes telomere deprotection, activates DNA damage signalling, and determines cell fate in response to a prolonged delay in mitosis. PMID:27230693

  8. SKF95365 induces apoptosis and cell-cycle arrest by disturbing oncogenic Ca2+ signaling in nasopharyngeal carcinoma cells

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    Zhang J

    2015-10-01

    Full Text Available Jinyan Zhang,1 Jiazhang Wei,2 Qian He,3 Yan Lin,1 Rong Liang,1 Jiaxiang Ye,1 Zhe Zhang,4 Yongqiang Li1 1Department of Medical Oncology, Affiliated Cancer Hospital of Guangxi Medical University, 2Department of Otolaryngology-Head and Neck Oncology, The People’s Hospital of Guangxi Zhuang Autonomous Region, Nanning, People’s Republic of China; 3Graduate School of Information Science and Technology, Hokkaido University, Sapporo, Japan; 4Department of Otolaryngology-Head & Neck Surgery, First Affiliated Hospital of Guangxi Medical University, Nanning, People’s Republic of China Background: Aberrant modulation of store-operated calcium ions (Ca2+ entry promotes the progression of human malignancies. Previously, we reported that the blockage of store-operated Ca2+ entry inhibited epidermal growth factor (EGF-stimulated migration and distant metastasis in nasopharyngeal carcinoma (NPC cells. However, the effects of pharmacological blocker on other Ca2+ signaling-regulated malignant characteristics in NPC cells remained poorly understood. Methods: We examined the effects of SKF96365, an inhibitor of store-operated Ca2+ channel, on EGF-launched Ca2+ signaling in two NPC cell lines. We determined the effects of SKF96365 on cell proliferation, colony formation, apoptosis, and cell-cycle status in vitro. We further elucidated the antitumor activity of SKF96365 in xenograft-bearing mice. Results: It was found that SKF96365 disturbed the thapsigargin (TG-stimulated Ca2+ release from endoplasmic reticulum and the subsequent Ca2+ influx. SKF96365 alone stimulated Ca2+ responses merely due to endoplasmic reticulum-released Ca2+. SKF96365 promoted cell mortality, inhibited colony formation, and induced apoptosis and cell-cycle arrest, while blunting the EGF-evoked Ca2+ signaling. Furthermore, we confirmed that SKF96365 reduced NPC xenograft growth while activating caspase-7-related apoptotic pathway. Conclusion: SKF96365 exerts multiple antitumor

  9. MicroRNA-99a induces G1-phase cell cycle arrest and suppresses tumorigenicity in renal cell carcinoma

    International Nuclear Information System (INIS)

    A growing body of evidence suggests that microRNAs (miRNAs) play an important role in cancer diagnosis and therapy. MicroRNA-99a (miR-99a), a potential tumor suppressor, is downregulated in several human malignancies. The expression and function of miR-99a, however, have not been investigated in human renal cell carcinoma (RCC) so far. We therefore examined the expression of miR-99a in RCC cell lines and tissues, and assessed the impact of miR-99a on the tumorigenesis of RCC. MiR-99a levels in 40 pairs of RCC and matched adjacent non-tumor tissues were assessed by real-time quantitative Reverse Transcription PCR (qRT-PCR). The RCC cell lines 786-O and OS-RC-2 were transfected with miR-99a mimics to restore the expression of miR-99a. The effects of miR-99a were then assessed by cell proliferation, cell cycle, transwell, and colony formation assay. A murine xenograft model of RCC was used to confirm the effect of miR-99a on tumorigenicity in vivo. Potential target genes were identified by western blotting and luciferase reporter assay. We found that miR-99a was remarkably downregulated in RCC and low expression level of miR-99a was correlated with poor survival of RCC patients. Restoration of miR-99a dramatically suppressed RCC cells growth, clonability, migration and invasion as well as induced G1-phase cell cycle arrest in vitro. Moreover, intratumoral delivery of miR-99a could inhibit tumor growth in murine xenograft models of human RCC. In addition, we also fond that mammalian target of rapamycin (mTOR) was a direct target of miR-99a in RCC cells. Furthermore, siRNA-mediated knockdown of mTOR partially phenocopied the effect of miR-99a overexpression, suggesting that the tumor suppressive role of miR-99a may be mediated primarily through mTOR regulation. Collectively, these results demonstrate for the first time, to our knowledge, that deregulation of miR-99a is involved in the etiology of RCC partially via direct targeting mTOR pathway, which suggests that mi

  10. MiR-107 and MiR-185 can induce cell cycle arrest in human non small cell lung cancer cell lines.

    Directory of Open Access Journals (Sweden)

    Yukari Takahashi

    Full Text Available BACKGROUND: MicroRNAs (miRNAs are short single stranded noncoding RNAs that suppress gene expression through either translational repression or degradation of target mRNAs. The annealing between messenger RNAs and 5' seed region of miRNAs is believed to be essential for the specific suppression of target gene expression. One miRNA can have several hundred different targets in a cell. Rapidly accumulating evidence suggests that many miRNAs are involved in cell cycle regulation and consequentially play critical roles in carcinogenesis. METHODOLOGY/PRINCIPAL FINDINGS: Introduction of synthetic miR-107 or miR-185 suppressed growth of the human non-small cell lung cancer cell lines. Flow cytometry analysis revealed these miRNAs induce a G1 cell cycle arrest in H1299 cells and the suppression of cell cycle progression is stronger than that by Let-7 miRNA. By the gene expression analyses with oligonucleotide microarrays, we find hundreds of genes are affected by transfection of these miRNAs. Using miRNA-target prediction analyses and the array data, we listed up a set of likely targets of miR-107 and miR-185 for G1 cell cycle arrest and validate a subset of them using real-time RT-PCR and immunoblotting for CDK6. CONCLUSIONS/SIGNIFICANCE: We identified new cell cycle regulating miRNAs, miR-107 and miR-185, localized in frequently altered chromosomal regions in human lung cancers. Especially for miR-107, a large number of down-regulated genes are annotated with the gene ontology term 'cell cycle'. Our results suggest that these miRNAs may contribute to regulate cell cycle in human malignant tumors.

  11. Differential regulation of vitamin D receptor expression in distinct leukemic cell lines upon phorbol ester-induced growth arrest

    Directory of Open Access Journals (Sweden)

    Folgueira M.A.A.K.

    2000-01-01

    Full Text Available A close correlation between vitamin D receptor (VDR abundance and cell proliferation rate has been shown in NIH-3T3 fibroblasts, MCF-7 breast cancer and in HL-60 myeloblastic cells. We have now determined if this association occurs in other leukemic cell lines, U937 and K562, and if VDR content is related to c-myc expression, which is also linked to cell growth state. Upon phorbol myristate acetate (PMA treatment, cells from the three lineages (HL-60, U937 and K562 differentiated and expressed specific surface antigens. All cell lines analyzed were growth inhibited by PMA and the doubling time was increased, mainly due to an increased fraction of cells in the G0/G1 phase, as determined by flow cytometry measurements of incorporated bromodeoxyuridine and cell DNA content. C-myc mRNA expression was down-regulated and closely correlated to cell growth arrest. However, VDR expression in leukemic cell lines, as determined by immunofluorescence and Northern blot assays, was not consistently changed upon inhibition of cell proliferation since VDR levels were down-regulated only in HL-60 cells. Our data suggest that VDR expression cannot be explained simply as a reflection of the leukemic cell growth state.

  12. High-density growth arrest in Ras-transformed cells: low Cdk kinase activities in spite of absence of p27Kip Cdk-complexes

    DEFF Research Database (Denmark)

    Groth, Anja; Willumsen, Berthe Marie

    2005-01-01

    and Cdk2 complexes, as these kinases were inactivated. Ras-transformed cells failed to arrest at normal saturation density and showed no significant alterations in cell control complexes at this point. Yet, at an elevated density the Ras-transformed cells ceased to proliferate and entered a quiescent......-like state with low Cdk4 and Cdk2 activity. Surprisingly, this delayed arrest was molecularly distinct from contact inhibition of normal cells, as it occurred in the absence of p27Kip1 induction and cyclin D1 levels remained high. This demonstrates that although oncogenic Ras efficiently disabled the normal...

  13. Curcumin-treated cancer cells show mitotic disturbances leading to growth arrest and induction of senescence phenotype.

    Science.gov (United States)

    Mosieniak, Grażyna; Sliwinska, Małgorzata A; Przybylska, Dorota; Grabowska, Wioleta; Sunderland, Piotr; Bielak-Zmijewska, Anna; Sikora, Ewa

    2016-05-01

    Cellular senescence is recognized as a potent anticancer mechanism that inhibits carcinogenesis. Cancer cells can also undergo senescence upon chemo- or radiotherapy. Curcumin, a natural polyphenol derived from the rhizome of Curcuma longa, shows anticancer properties both in vitro and in vivo. Previously, we have shown that treatment with curcumin leads to senescence of human cancer cells. Now we identified the molecular mechanism underlying this phenomenon. We observed a time-dependent accumulation of mitotic cells upon curcumin treatment. The time-lapse analysis proved that those cells progressed through mitosis for a significantly longer period of time. A fraction of cells managed to divide or undergo mitotic slippage and then enter the next phase of the cell cycle. Cells arrested in mitosis had an improperly formed mitotic spindle and were positive for γH2AX, which shows that they acquired DNA damage during prolonged mitosis. Moreover, the DNA damage response pathway was activated upon curcumin treatment and the components of this pathway remained upregulated while cells were undergoing senescence. Inhibition of the DNA damage response decreased the number of senescent cells. Thus, our studies revealed that the induction of cell senescence upon curcumin treatment resulted from aberrant progression through the cell cycle. Moreover, the DNA damage acquired by cancer cells, due to mitotic disturbances, activates an important molecular mechanism that determines the potential anticancer activity of curcumin. PMID:26916504

  14. G0/G1 arrest and apoptosis induced by SARS-CoV 3b protein in transfected cells

    Directory of Open Access Journals (Sweden)

    Chen Jiapei

    2005-08-01

    Full Text Available Abstract Severe Acute Respiratory Syndrome coronavirus (SARS-CoV, cause of the life-threatening atypical pneumonia, infects many organs, such as lung, liver and immune organ, and induces parenchyma cells apoptosis and necrosis. The genome of SARS-CoV, not closely related to any of the previously characterized coronavirus, encodes replicase and four major structural proteins and a number of non-structural proteins. Published studies suggest that some non-structural proteins may play important roles in the replication, virulence and pathogenesis of viruses. Among the potential SARS-CoV non-structural proteins, 3b protein (ORF4 is predicted encoding 154 amino acids, lacking significant similarities to any known proteins. Till now, there is no report about the function of 3b protein. In this study, 3b gene was linked with the EGFP tag at the C- terminus. Through cell cycle analysis, it was found that over-expression of 3b-EGFP protein in Vero, 293 and COS-7 cells could induce cell cycle arrest at G0/G1 phase, and that especially in COS-7 cells, expression of 3b-EGFP was able to induce the increase of sub-G1 phase from 24 h after transfection, which was most obvious at 48 h. The apoptosis induction of 3b fusion protein in COS-7 cells was further confirmed by double cell labeling with 7-AAD and Annexin V, the function of 3b protein inducing cell G0/G1 arrest and apoptosis may provide a new insight for further study on the mechanism of SARS pathogenesis.

  15. Lyme disease and relapsing fever Borrelia elongate through zones of peptidoglycan synthesis that mark division sites of daughter cells.

    Science.gov (United States)

    Jutras, Brandon Lyon; Scott, Molly; Parry, Bradley; Biboy, Jacob; Gray, Joe; Vollmer, Waldemar; Jacobs-Wagner, Christine

    2016-08-16

    Agents that cause Lyme disease, relapsing fever, leptospirosis, and syphilis belong to the phylum Spirochaetae-a unique lineage of bacteria most known for their long, spiral morphology. Despite the relevance to human health, little is known about the most fundamental aspects of spirochete growth. Here, using quantitative microscopy to track peptidoglycan cell-wall synthesis, we found that the Lyme disease spirochete Borrelia burgdorferi displays a complex pattern of growth. B. burgdorferi elongates from discrete zones that are both spatially and temporally regulated. In addition, some peptidoglycan incorporation occurs along the cell body, with the notable exception of a large region at the poles. Newborn cells inherit a highly active zone of peptidoglycan synthesis at midcell that contributes to elongation for most of the cell cycle. Concomitant with the initiation of nucleoid separation and cell constriction, second and third zones of elongation are established at the 1/4 and 3/4 cellular positions, marking future sites of division for the subsequent generation. Positioning of elongation zones along the cell is robust to cell length variations and is relatively precise over long distances (>30 µm), suggesting that cells ‟sense" relative, as opposed to absolute, cell length to establish zones of peptidoglycan synthesis. The transition from one to three zones of peptidoglycan growth during the cell cycle is also observed in relapsing fever Borrelia. However, this mode of growth does not extend to representative species from other spirochetal genera, suggesting that this distinctive growth mode represents an evolutionary divide in the spirochete phylum. PMID:27506799

  16. Flavokawain derivative FLS induced G2/M arrest and apoptosis on breast cancer MCF-7 cell line.

    Science.gov (United States)

    Ali, Norlaily Mohd; Akhtar, M Nadeem; Ky, Huynh; Lim, Kian Lam; Abu, Nadiah; Zareen, Seema; Ho, Wan Yong; Alan-Ong, Han Kiat; Tan, Sheau Wei; Alitheen, Noorjahan Banu; Ismail, Jamil Bin; Yeap, Swee Keong; Kamarul, Tunku

    2016-01-01

    Known as naturally occurring biologically active compounds, flavokawain A and B are the leading chalcones that possess anticancer properties. Another flavokawain derivative, (E)-1-(2'-Hydroxy-4',6'-dimethoxyphenyl)-3-(4-methylthio)phenyl)prop-2-ene-1-one (FLS) was characterized with (1)H-nuclear magnetic resonance, electron-impact mas spectrometry, infrared spectroscopy, and ultraviolet ((1)H NMR, EI-MS, IR, and UV) spectroscopic techniques. FLS cytotoxic efficacy against human cancer cells (MCF-7, MDA-MB-231, and MCF-10A) resulted in the reduction of IC50 values in a time- and dose-dependent mode with high specificity on MCF-7 (IC50 of 36 μM at 48 hours) against normal breast cell MCF-10A (no IC50 detected up to 180 μM at 72 hours). Light, scanning electron, and fluorescent microscopic analysis of MCF-7 cells treated with 36 μM of FLS displayed cell shrinkage, apoptotic body, and DNA fragmentation. Additionally, induction of G2/M cell arrest within 24 hours and apoptosis at subsequent time points was discovered via flow cytometry analysis. The roles of PLK-1, Wee-1, and phosphorylation of CDC-2 in G2/M arrest and proapoptotic factors (Bax, caspase 9, and p53) in promotion of apoptosis of FLS against MCF-7 cells were discovered using fluorometric, quantitative real-time polymerase chain reaction, and Western blot analysis. Interestingly, the presence of SCH3 (thiomethyl group) on ring B structure contributed to the selective cytotoxicity against MCF-7 cells compared to other chalcones, flavokawain A and B. Overall, our data suggest potential therapeutic value for flavokawain derivative FLS to be further developed as a new anticancer drug. PMID:27358555

  17. Flavokawain derivative FLS induced G2/M arrest and apoptosis on breast cancer MCF-7 cell line

    Science.gov (United States)

    Ali, Norlaily Mohd; Akhtar, M Nadeem; Ky, Huynh; Lim, Kian Lam; Abu, Nadiah; Zareen, Seema; Ho, Wan Yong; Alan-Ong, Han Kiat; Tan, Sheau Wei; Alitheen, Noorjahan Banu; Ismail, Jamil bin; Yeap, Swee Keong; Kamarul, Tunku

    2016-01-01

    Known as naturally occurring biologically active compounds, flavokawain A and B are the leading chalcones that possess anticancer properties. Another flavokawain derivative, (E)-1-(2′-Hydroxy-4′,6′-dimethoxyphenyl)-3-(4-methylthio)phenyl)prop-2-ene-1-one (FLS) was characterized with 1H-nuclear magnetic resonance, electron-impact mas spectrometry, infrared spectroscopy, and ultraviolet (1H NMR, EI-MS, IR, and UV) spectroscopic techniques. FLS cytotoxic efficacy against human cancer cells (MCF-7, MDA-MB-231, and MCF-10A) resulted in the reduction of IC50 values in a time- and dose-dependent mode with high specificity on MCF-7 (IC50 of 36 μM at 48 hours) against normal breast cell MCF-10A (no IC50 detected up to 180 μM at 72 hours). Light, scanning electron, and fluorescent microscopic analysis of MCF-7 cells treated with 36 μM of FLS displayed cell shrinkage, apoptotic body, and DNA fragmentation. Additionally, induction of G2/M cell arrest within 24 hours and apoptosis at subsequent time points was discovered via flow cytometry analysis. The roles of PLK-1, Wee-1, and phosphorylation of CDC-2 in G2/M arrest and proapoptotic factors (Bax, caspase 9, and p53) in promotion of apoptosis of FLS against MCF-7 cells were discovered using fluorometric, quantitative real-time polymerase chain reaction, and Western blot analysis. Interestingly, the presence of SCH3 (thiomethyl group) on ring B structure contributed to the selective cytotoxicity against MCF-7 cells compared to other chalcones, flavokawain A and B. Overall, our data suggest potential therapeutic value for flavokawain derivative FLS to be further developed as a new anticancer drug. PMID:27358555

  18. Double-detargeted oncolytic adenovirus shows replication arrest in liver cells and retains neuroendocrine cell killing ability.

    Directory of Open Access Journals (Sweden)

    Justyna Leja

    Full Text Available BACKGROUND: We have previously developed an oncolytic serotype 5 adenovirus (Ad5 with chromogranin-A (CgA promoter-controlled E1A expression, Ad[CgA-E1A], with the intention to treat neuroendocrine tumors, including carcinoids. Since carcinoids tend to metastasize to the liver it is important to fully repress viral replication in hepatocytes to avoid adenovirus-related liver toxicity. Herein, we explore miRNA-based regulation of E1A expression as a complementary mechanism to promoter-based transcriptional control. METHODOLOGY/PRINCIPAL FINDINGS: Ad[CgA-E1A-miR122], where E1A expression is further controlled by six tandem repeats of the target sequence for the liver-specific miR122, was constructed and compared to Ad[CgA-E1A]. We observed E1A suppression and replication arrest of the miR122-detargeted adenovirus in normal hepatocytes, while the two viruses killed carcinoid cells to the same degree. Repeated intravenous injections of Ad[CgA-E1A] induced liver toxicity in mice while Ad[CgA-E1A-miR122] injections did not. Furthermore, a miR122-detargeted adenovirus with the wild-type E1A promoter showed reduced replication in hepatic cells compared to wild-type Ad5 but not to the same extent as the miR122-detargeted adenovirus with the neuroendocrine-selective CgA promoter. CONCLUSIONS/SIGNIFICANCE: A combination of transcriptional (promoter and post-transcriptional (miRNA target regulation to control virus replication may allow for the use of higher doses of adenovirus for efficient tumors treatment without liver toxicity.

  19. A class of DNA-binding peptides from wheat bud causes growth inhibition, G2 cell cycle arrest and apoptosis induction in HeLa cells

    Directory of Open Access Journals (Sweden)

    Elgjo Kjell

    2009-07-01

    Full Text Available Abstract Background Deproteinized DNA from eukaryotic and prokaryotic cells still contains a low-molecular weight peptidic fraction which can be dissociated by alkalinization of the medium. This fraction inhibits RNA transcription and tumor cell growth. Removal from DNA of normal cells causes amplification of DNA template activity. This effect is lower or absent in several cancer cell lines. Likewise, the amount of active peptides in cancer cell DNA extracts is lower than in DNA preparation of the corresponding normal cells. Such evidence, and their ubiquitous presence, suggests that they are a regulatory, conserved factor involved in the control of normal cell growth and gene expression. Results We report that peptides extracted from wheat bud chromatin induce growth inhibition, G2 arrest and caspase-dependent apoptosis in HeLa cells. The growth rate is decreased in cells treated during the S phase only and it is accompanied by DNA damage and DNA synthesis inhibition. In G2 cells, this treatment induces inactivation of the CDK1-cyclin B1 complex and an increase of active chk1 kinase expression. Conclusion The data indicate that the chromatin peptidic pool inhibits HeLa cell growth by causing defective DNA replication which, in turn, arrests cell cycle progression to mitosis via G2 checkpoint pathway activation.

  20. Synthesis, interaction with DNA, cytotoxicity, cell cycle arrest and apoptotic inducing properties of ruthenium(II) molecular "light switch" complexes.

    Science.gov (United States)

    Shobha Devi, C; Anil Kumar, D; Singh, Surya S; Gabra, Nazar; Deepika, N; Kumar, Y Praveen; Satyanarayana, S

    2013-06-01

    In an endeavor toward the development of metal-based anticancer drugs, we present here the design, synthesis and characterization of three ruthenium(II) functionalized phenanthroline complexes with extended π-conjugation. These complexes have been shown to act as promising CT-DNA intercalators as evidenced by UV-visible, luminescence, emission quenching by [Fe(CN)6](4-), DNA competitive binding with ethidium bromide and salt dependent studies. All three complexes [Ru(Hdpa)2PPIP](2+) (1), [Ru(Hdpa)2PIP](2+) (2), [Ru(Hdpa)24HEPIP](2+) (3) clearly demonstrated that they can bind to DNA through the intercalation mode. Cell viability experiments indicated that all complexes showed significant dose dependent cytotoxicity in selected cell lines. The apoptosis and cell cycle arrest were also investigated. The complexes were docked into DNA-base-pairs using the 'GOLD' (Genetic Optimization for Ligand Docking), docking program. PMID:23665797

  1. Exposure of Human Lung Cancer Cells to 8-Chloro-Adenosine Induces G2/M Arrest and Mitotic Catastrophe

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    Hong-Yu Zhang

    2004-11-01

    Full Text Available 8-Chloro-adenosine (8-CI-Ado is a potent chemotherapeutic agent whose cytotoxicity in a variety of tumor cell lines has been widely investigated. However, the molecular mechanisms are uncertain. In this study, we found that exposure of human lung cancer cell lines A549 (p53-wt and H1299 (p53-depleted to 8-CI-Ado induced cell arrest in the G2/M phase, which was accompanied by accumulation of binucleated and polymorphonucleated cells resulting from aberrant mitosis and failed cytokinesis. Western blotting showed the loss of phosphorylated forms of Cdc2 and Cdc25C that allowed progression into mitosis. Furthermore, the increase in Ser10-phosphorylated histone H3-positive cells revealed by fluorescence-activated cell sorting suggested that the agent-targeted cells were able to exit the G2 phase and enter the M phase. Immunocytochemistry showed that microtubule and microfilament arrays were changed in exposed cells, indicating that the dynamic instability of microtubules and microfilaments was lost, which may correlate with mitotic dividing failure. Aberrant mitosis resulted in mitotic catastrophe followed by varying degrees of apoptosis, depending on the cell lines. Thus, 8-CI-Ado appears to exert its cytotoxicity toward cells in culture by inducing mitotic catastrophe.

  2. Silica Nanoparticles Sensitize Human Multiple Myeloma Cells to Snake (Walterinnesia aegyptia Venom-Induced Apoptosis and Growth Arrest

    Directory of Open Access Journals (Sweden)

    Douaa Sayed

    2012-01-01

    Full Text Available Background. Multiple myeloma (MM, an almost incurable disease, is the second most common blood cancer. Initial chemotherapeutic treatment could be successful; however, resistance development urges the use of higher toxic doses accompanied by hematopoietic stem cell transplantation. The establishment of more effective treatments that can overcome or circumvent chemoresistance has become a priority. We recently demonstrated that venom extracted from Walterinnesia aegyptia (WEV either alone or in combination with silica nanoparticles (WEV+NPs mediated the growth arrest and apoptosis of prostate cancer cells. In the present study, we evaluated the impact of WEV alone and WEV+NP on proliferation and apoptosis of MM cells. Methods. The impacts of WEV alone and WEV+NP were monitored in MM cells from 70 diagnosed patients. The influences of WEV and WEV+NP were assessed with flow cytometry analysis. Results. WEV alone and WEV+NP decreased the viability of MM cells. Using a CFSE proliferation assay, we found that WEV+NP strongly inhibited MM cell proliferation. Furthermore, analysis of the cell cycle using the propidium iodide (PI staining method indicated that WEV+NP strongly altered the cell cycle of MM cells and enhanced the induction of apoptosis. Conclusions. Our data reveal the biological effects of WEV and WEV+NP on MM cells that enable these compounds to function as effective treatments for MM.

  3. Crambescidin-816 Acts as a Fungicidal with More Potency than Crambescidin-800 and -830, Inducing Cell Cycle Arrest, Increased Cell Size and Apoptosis in Saccharomyces cerevisiae

    OpenAIRE

    Vega, Félix V.; Vieytes, Mercedes R.; Botana, Luis M; Thomas, Olivier P.; Henar López-Alonso; Rubiolo, Juan A.; Eva Ternon

    2013-01-01

    In this paper, we show the effect of crambescidin-816, -800, and -830 on Saccharomyces cerevisiae viability. We determined that, of the three molecules tested, crambescidin-816 was the most potent. Based on this result, we continued by determining the effect of crambescidin-816 on the cell cycle of this yeast. The compound induced cell cycle arrest in G2/M followed by an increase in cell DNA content and size. When the type of cell death was analyzed, we observed that crambescidin-816 induced ...

  4. Platinum(IV) complex LA-12 induced apoptosis and only partial cell cycle arrest in colon carcinoma cell line HCT-116

    Czech Academy of Sciences Publication Activity Database

    Vondálová Blanářová, Olga; Jelínková, Iva; Jendželovský, R.; Souček, Karel; Hofmanová, Jiřina; Sova, P.; Kozubík, Alois

    Paris, 2009. s. 294. [17th ECDO Euroconference on Apoptosis, Destruction, Degradation and Death Cell Death Control in Cancer and Neurodegeneration, 6th Training Course on Concepts and Methods in Programmed Cell Death. 23.09.2009-26.09.2009, Paris] R&D Projects: GA AV ČR(CZ) 1QS500040507; GA ČR(CZ) GA301/07/1557 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : cell death * cell cycle arrest * platinum compounds Subject RIV: BO - Biophysics

  5. The zinc ionophore clioquinol reverses autophagy arrest in chloroquine-treated ARPE-19 cells and in APP/mutant presenilin-1-transfected Chinese hamster ovary cells.

    Science.gov (United States)

    Seo, Bo-Ra; Lee, Sook-Jeong; Cho, Kyung Sook; Yoon, Young Hee; Koh, Jae-Young

    2015-12-01

    Arrested autophagy may contribute to the pathogenesis of Alzheimer's disease. Because we found that chloroquine (CQ) causes arrested autophagy but clioquinol (ClioQ), a zinc ionophore, activates autophagic flux, in the present study, we examined whether ClioQ can overcome arrested autophagy induced by CQ or mutant presenilin-1 (mPS1). CQ induced vacuole formation and cell death in adult retinal pigment epithelial (ARPE-19) cells, but co-treatment with ClioQ attenuated CQ-associated toxicity in a zinc-dependent manner. Increases in lysosome dilation and blockage of autophagic flux by CQ were also markedly attenuated by ClioQ treatment. Interestingly, CQ increased lysosomal pH in amyloid precursor protein (APP)/mPS1-expressing Chinese hamster ovary 7WΔE9 (CHO-7WΔE9) cell line, and ClioQ partially re-acidified lysosomes. Furthermore, accumulation of amyloid-β (Aβ) oligomers in CHO-7WΔE9 cells was markedly attenuated by ClioQ. Moreover, intracellular accumulation of exogenously applied fluorescein isothiocyanate-conjugated Aβ(1-42) was also increased by CQ but was returned to control levels by ClioQ. These results suggest that modulation of lysosomal functions by manipulating lysosomal zinc levels may be a useful strategy for clearing intracellular Aβ oligomers. PMID:26453000

  6. Drosophila neuroblasts retain the daughter centrosome

    OpenAIRE

    Januschke, Jens; Llamazares, Salud; Reina, Jose; Gonzalez, Cayetano

    2011-01-01

    During asymmetric mitosis, both in male Drosophila germline stem cells and in mouse embryo neural progenitors, the mother centrosome is retained by the self-renewed cell; hence suggesting that mother centrosome inheritance might contribute to stemness. We test this hypothesis in Drosophila neuroblasts (NBs) tracing photo converted centrioles and a daughter-centriole-specific marker generated by cloning the Drosophila homologue of human Centrobin. Here we show that upon asymmetric mitosis, the...

  7. Chikusetsusaponin IVa methyl ester induces cell cycle arrest by the inhibition of nuclear translocation of β-catenin in HCT116 cells

    International Nuclear Information System (INIS)

    We demonstrate that chikusetsusaponin IVa methyl ester (CME), a triterpenoid saponin from the root of Achyranthes japonica, has an anticancer activity. We investigate its molecular mechanism in depth in HCT116 cells. CME reduces the amount of β-catenin in nucleus and inhibits the binding of β-catenin to specific DNA sequences (TCF binding elements, TBE) in target gene promoters. Thus, CME appears to decrease the expression of cell cycle regulatory proteins such as Cyclin D1, as a representative target for β-catenin, as well as CDK2 and CDK4. As a result of the decrease of the cell cycle regulatory proteins, CME inhibits cell proliferation by arresting the cell cycle at the G0/G1 phase. Therefore, we suggest that CME as a novel Wnt/β-catenin inhibitor can be a putative agent for the treatment of colorectal cancers. - Highlights: • CME inhibits cell proliferation in HCT116 cells. • CME increases cell cycle arrest at G0/G1 phase and apoptosis. • CME attenuates cyclin D1 and regulates cell cycle regulatory proteins. • CME inhibits β-catenin translocation to nucleus

  8. Chikusetsusaponin IVa methyl ester induces cell cycle arrest by the inhibition of nuclear translocation of β-catenin in HCT116 cells

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kyung-Mi [Natural Products Research Institute, College of Pharmacy, Seoul National University, Seoul (Korea, Republic of); Yun, Ji Ho [Natural Products Research Center, Korea Institute of Science and Technology, Gangneung, 210-340 (Korea, Republic of); Lee, Dong Hwa [Department of Food Science and Nutrition, Andong National University, Andong 760-749 (Korea, Republic of); Park, Young Gyun [Natural Products Research Center, Korea Institute of Science and Technology, Gangneung, 210-340 (Korea, Republic of); Son, Kun Ho [Department of Food Science and Nutrition, Andong National University, Andong 760-749 (Korea, Republic of); Nho, Chu Won, E-mail: cwnho@kist.re.kr [Natural Products Research Center, Korea Institute of Science and Technology, Gangneung, 210-340 (Korea, Republic of); Kim, Yeong Shik, E-mail: kims@snu.ac.kr [Natural Products Research Institute, College of Pharmacy, Seoul National University, Seoul (Korea, Republic of)

    2015-04-17

    We demonstrate that chikusetsusaponin IVa methyl ester (CME), a triterpenoid saponin from the root of Achyranthes japonica, has an anticancer activity. We investigate its molecular mechanism in depth in HCT116 cells. CME reduces the amount of β-catenin in nucleus and inhibits the binding of β-catenin to specific DNA sequences (TCF binding elements, TBE) in target gene promoters. Thus, CME appears to decrease the expression of cell cycle regulatory proteins such as Cyclin D1, as a representative target for β-catenin, as well as CDK2 and CDK4. As a result of the decrease of the cell cycle regulatory proteins, CME inhibits cell proliferation by arresting the cell cycle at the G0/G1 phase. Therefore, we suggest that CME as a novel Wnt/β-catenin inhibitor can be a putative agent for the treatment of colorectal cancers. - Highlights: • CME inhibits cell proliferation in HCT116 cells. • CME increases cell cycle arrest at G0/G1 phase and apoptosis. • CME attenuates cyclin D1 and regulates cell cycle regulatory proteins. • CME inhibits β-catenin translocation to nucleus.

  9. Overexpression of p27KIP1 induced cell cycle arrest in G1 phase and subsequent apoptosis in HCC-9204 cell line

    Institute of Scientific and Technical Information of China (English)

    Jiang Li; Wen Liang Wang; Xin Ke Yang; Xin Xin Yu; Yun De Hou; Meng Liang Ge; Jie Zhang

    2000-01-01

    AIM We have previously reported that inducible over-expresaion of Bak may prolong cell cycle in G1 phase and lead to apoptosis in HCC-9204 cells. This study is to investigate whether p27KIP1 plays an important role in this process. MEHODS In order to elucidate the exact function of p27KIP1 in this process, a zinc inducible p27KIP1 stable transfectant and transient p27KIP1- GFP fusion transfectant were constructed. The effects of inducible p27KIP1 on cell growth, cell cycle arrest and apoptosis were examined in the mock, control pMD vector, and pMD-KIP1 transfected HCC-9204 cells. RESULTS This p27KIP1-GFP transfectant may transiently express the fusion gene. The cell growth was reduced by 35% at 48 h of p27KIP1 induction with zinc treatment as determined by trypan blue exclusion assay. These differences remained the same after 72 h of p27KIP1 expression, p27KIP1 caused cell cycle arrest after 24 h of induction, with 40% increase in G1 population. Prolonged p27KIP1 expression in this cell line induced apoptotic cell death reflected by TUNEL assay. Fourty-eight h and 72 h of p27KIP1 expression showed a characteristic DNA ladder on agarose gel electrophoresis.

  10. Enhanced induction of cell cycle arrest and apoptosis via the mitochondrial membrane potential disruption in human U87 malignant glioma cells by aloe emodin.

    Science.gov (United States)

    Ismail, Samhani; Haris, Khalilah; Abdul Ghani, Abdul Rahman Izaini; Abdullah, Jafri Malin; Johan, Muhammad Farid; Mohamed Yusoff, Abdul Aziz

    2013-09-01

    Aloe emodin, one of the active compounds found in Aloe vera leaves, plays an important role in the regulation of cell growth and death. It has been reported to promote the anti-cancer effects in various cancer cells by inducing apoptosis. However, the mechanism of inducing apoptosis by this agent is poorly understood in glioma cells. This research is to investigate the apoptosis and cell cycle arrest inducing by aloe emodin on U87 human malignant glioma cells. Aloe emodin showed a time- and dose-dependent inhibition of U87 cells proliferation and decreased the percentage of viable U87 cells via the induction of apoptosis. Characteristic morphological changes, such as the formation of apoptotic bodies, were observed with confocal microscope by Annexin V-FITC/PI staining, supporting our viability study and flow cytometry analysis results. Our data also demonstrated that aloe emodin arrested the cell cycle in the S phase and promoted the loss of mitochondrial membrane potential in U87 cells that indicated the early event of the mitochondria-induced apoptotic pathway. PMID:23869465

  11. The ethanol extract of Scutellaria baicalensis and the active compounds induce cell cycle arrest and apoptosis including upregulation of p53 and Bax in human lung cancer cells

    International Nuclear Information System (INIS)

    Despite a lack of scientific authentication, Scutellaria baicalensis is clinically used in Chinese medicine as a traditional adjuvant to chemotherapy of lung cancer. In this study, cytotoxicity assays demonstrated that crude ethanolic extracts of S. baicalensis were selectively toxic to human lung cancer cell lines A549, SK-LU-1 and SK-MES-1 compared with normal human lung fibroblasts. The active compounds baicalin, baicalein and wogonin did not exhibit such selectivity. Following exposure to the crude extracts, cellular protein expression in the cancer cell lines was assessed using 2D gel electrophoresis coupled with MALDI-TOF-MS/Protein Fingerprinting. The altered protein expression indicated that cell growth arrest and apoptosis were potential mechanisms of cytotoxicity. These observations were supported by PI staining cell cycle analysis using flow cytometry and Annexin-V apoptotic analysis by fluorescence microscopy of cancer cells treated with the crude extract and pure active compounds. Moreover, specific immunoblotting identification showed the decreased expression of cyclin A results in the S phase arrest of A549 whereas the G0/G1 phase arrest in SK-MES-1 cells results from the decreased expression of cyclin D1. Following treatment, increased expression in the cancer cells of key proteins related to the enhancement of apoptosis was observed for p53 and Bax. These results provide further insight into the molecular mechanisms underlying the clinical use of this herb as an adjuvant to lung cancer therapy. - Research highlights: → Scutellaria baicalensis is a clinical adjuvant to lung cancer chemotherapy in China. → Scutellaria ethanol extracts selectively toxic to A549, SK-LU-1 and SK-MES-1. → Baicalin, baicalein and wogonin were toxic to all lung cancer cell lines. → Proteomics identified increased p53 and BAX in response to Scutellaria extracts.

  12. Anti-Tumor Effect of Rutin on Human Neuroblastoma Cell Lines through Inducing G2/M Cell Cycle Arrest and Promoting Apoptosis

    Directory of Open Access Journals (Sweden)

    Hongyan Chen

    2013-01-01

    Full Text Available Aims. To further investigate the antineuroblastoma effect of rutin which is a type of flavonoid. Methods. The antiproliferation of rutin in human neuroblastoma cells LAN-5 were detected by 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT assay. Chemotaxis of LAN-5 cells was assessed using transwell migration chambers and scratch wound migration assay. The cell cycle arrest and apoptosis in a dose-dependent manner was measured by flow cytometric and fluorescent microscopy analyses. The apoptosis-related proteins BAX and BCL2 as well as MYCN mRNA express were determined by RT-PCR analysis. Secreted TNF-α level were determined using specific enzyme-linked immunosorbent assay kits. Results. Rutin significantly inhibited the growth of LAN-5 cells and chemotactic ability. Flow cytometric analysis revealed that rutin induced G2/M arrest in the cell cycle progression and induced cell apoptosis. The RT-PCR showed that rutin could decrease BCL2 expression and BCL2/BAX ratio. In the meantime, the MYCN mRNA level and the secretion of TNF-α were inhibited. Conclusion. These results suggest that rutin produces obvious antineuroblastoma effects via induced G2/M arrest in the cell cycle progression and induced cell apoptosis as well as regulating the expression of gene related to apoptosis and so on. It supports the viability of developing rutin as a novel therapeutic prodrug for neuroblastoma treatment, as well as providing a new path on anticancer effect of Chinese traditional drug.

  13. miR-6734 Up-Regulates p21 Gene Expression and Induces Cell Cycle Arrest and Apoptosis in Colon Cancer Cells

    Science.gov (United States)

    Kang, Moo Rim; Park, Ki Hwan; Yang, Jeong-Ook; Lee, Chang Woo; Oh, Soo Jin; Yun, Jieun; Lee, Myeong Youl; Han, Sang-Bae; Kang, Jong Soon

    2016-01-01

    Recently, microRNAs have been implicated in the regulation of gene expression in terms of both gene silencing and gene activation. Here, we investigated the effects of miR-6734, which has a sequence homology with a specific region of p21WAF1/CIP1 (p21) promoter, on cancer cell growth and the mechanisms involved in this effect. miR-6734 up-regulated p21 expression at both mRNA and protein levels and chromatin immunoprecipitation analysis using biotin-labeled miR-6734 confirmed the association of miR-6734 with p21 promoter. Moreover, miR-6734 inhibited cancer cell growth and induced cell cycle arrest and apoptosis in HCT-116 cells, which was abolished by knockdown of p21. The phosphorylation of Rb and the cleavage of caspase 3 and PARP were suppressed by miR-6734 transfection in HCT-116 cells and these effects were also reversed by p21 knockdown. In addition, miR-6734 transfection caused prolonged induction of p21 gene and modification of histones in p21 promoter, which are typical aspects of a phenomenon referred to as RNA activation (RNAa). Collectively, our results demonstrated that miR-6734 inhibits the growth of colon cancer cells by up-regulating p21 gene expression and subsequent induction of cell cycle arrest and apoptosis, suggesting its role as an important endogenous regulator of cancer cell proliferation and survival. PMID:27509128

  14. Maternal Influences on Daughters' Restrained Eating Behavior

    OpenAIRE

    Francis, Lori A.; Birch, Leann L

    2005-01-01

    This study examined whether mothers' preoccupation with their own weight and eating was linked to daughters' restrained eating behavior. Participants included 173 non-Hispanic, White mother–daughter dyads, measured longitudinally when daughters were ages 5, 7, 9, and 11. Mothers who were preoccupied with their own weight and eating reported higher levels of restricting daughters' intake and encouraging daughters to lose weight over time. Mothers' encouragement of daughters' weight loss was li...

  15. High-Dose {sup 111}In Induces G1 Cell Cycle Arrest and Cell Death in Rat Bone Marrow Mesenchymal Stem Cells

    Energy Technology Data Exchange (ETDEWEB)

    Park, Bok Nam; Shim, Woo Young; Ahn, Young Hwan; Lee, Jae Ho; Yoon, Joon Kee [Ajou Univ. School of Medicine, Suwon (Korea, Republic of)

    2012-06-15

    This study was performed to evaluate the effect of {sup 111}In-labeling on the cell growth, cycle and viability of bone marrow mesenchymal stem cells (BMSCs). Rat BMSCs were labeled with various doses of {sup 111}In (0.4-11.1 Bq/cell). The growth curve of {sup 111}In-BMSCs was obtained up to 14th day of labeling. The cell cycle was evaluated by 5-bromo-2-deoxyuridine (BrdU) labeling or prospidium iodide (PI) staining. Senescent cells were counted under a light microscope after staining with 5-bromo-4-chloro-3-indolyl-{sup D-}galactopyranoside. Flow cytometry was performed to measure apoptotic and necrotic fractions after staining with annexin V-FITC and PI. The growth of BMSCs labeled with higher doses of {sup 111}In (4.4 or 11.1 Bq/cell) was significantly inhibited from the 3rd day of labeling. Flow cytometry revealed less BrdU-positive BMSCs at 11.1 Bq {sup 111}In/cell (9.07%/3.18%) on the 14th day (control=1.60%/0.39%). However, no cellular senescence was visualized up to the 14th day. A high dose of {sup 111}In-labeling induced cell cycle arrest and death in BMSCs; therefore, it should be used with a careful dosimetry in case of applying it to humans.

  16. Quercetin induces cell cycle arrest and apoptosis in CD133+ cancer stem cells of human colorectal HT29 cancer cell line and enhances anticancer effects of doxorubicin

    Science.gov (United States)

    Atashpour, Shekoufeh; Fouladdel, Shamileh; Movahhed, Tahereh Komeili; Barzegar, Elmira; Ghahremani, Mohammad Hossein; Ostad, Seyed Nasser; Azizi, Ebrahim

    2015-01-01

    Objective(s): The colorectal cancer stem cells (CSCs) with the CD133+ phenotype are a rare fraction of cancer cells with the ability of self-renewal, unlimited proliferation and resistance to treatment. Quercetin has anticancer effects with the advantage of exhibiting low side effects. Therefore, we evaluated the anticancer effects of quercetin and doxorubicin (Dox) in HT29 cancer cells and its isolated CD133+ CSCs. Materials and Methods: The CSCs from HT29 cells were isolated using CD133 antibody conjugated to magnetic beads by MACS. Anticancer effects of quercetin and Dox alone and in combination on HT29 cells and CSCs were evaluated using MTT cytotoxicity assay and flow cytometry analysis of cell cycle distribution and apoptosis induction. Results: The CD133+ CSCs comprised about 10% of HT29 cells. Quercetin and Dox alone and in combination inhibited cell proliferation and induced apoptosis in HT29 cells and to a lesser extent in CSCs. Quercetin enhanced cytotoxicity and apoptosis induction of Dox at low concentration in both cell populations. Quercetin and Dox and their combination induced G2/M arrest in the HT29 cells and to a lesser extent in CSCs. Conclusion: The CSCs were a minor population with a significantly high level of drug resistance within the HT29 cancer cells. Quercetin alone exhibited significant cytotoxic effects on HT29 cells and also increased cytoxicity of Dox in combination therapy. Altogether, our data showed that adding quercetin to Dox chemotherapy is an effective strategy for treatment of both CSCs and bulk tumor cells. PMID:26351552

  17. The Forkhead Transcription Factor FOXP2 Is Required for Regulation of p21WAF1/CIP1 in 143B Osteosarcoma Cell Growth Arrest.

    Directory of Open Access Journals (Sweden)

    Duncan M Gascoyne

    Full Text Available Mutations of the forkhead transcription factor FOXP2 gene have been implicated in inherited speech-and-language disorders, and specific Foxp2 expression patterns in neuronal populations and neuronal phenotypes arising from Foxp2 disruption have been described. However, molecular functions of FOXP2 are not completely understood. Here we report a requirement for FOXP2 in growth arrest of the osteosarcoma cell line 143B. We observed endogenous expression of this transcription factor both transiently in normally developing murine osteoblasts and constitutively in human SAOS-2 osteosarcoma cells blocked in early osteoblast development. Critically, we demonstrate that in 143B osteosarcoma cells with minimal endogenous expression, FOXP2 induced by growth arrest is required for up-regulation of p21WAF1/CIP1. Upon growth factor withdrawal, FOXP2 induction occurs rapidly and precedes p21WAF1/CIP1 activation. Additionally, FOXP2 expression could be induced by MAPK pathway inhibition in growth-arrested 143B cells, but not in traditional cell line models of osteoblast differentiation (MG-63, C2C12, MC3T3-E1. Our data are consistent with a model in which transient upregulation of Foxp2 in pre-osteoblast mesenchymal cells regulates a p21-dependent growth arrest checkpoint, which may have implications for normal mesenchymal and osteosarcoma biology.

  18. Tocotrienol-Rich Fraction Prevents Cell Cycle Arrest and Elongates Telomere Length in Senescent Human Diploid Fibroblasts

    Directory of Open Access Journals (Sweden)

    Suzana Makpol

    2011-01-01

    Full Text Available This study determined the molecular mechanisms of tocotrienol-rich fraction (TRF in preventing cellular senescence of human diploid fibroblasts (HDFs. Primary culture of HDFs at various passages were incubated with 0.5 mg/mL TRF for 24 h. Telomere shortening with decreased telomerase activity was observed in senescent HDFs while the levels of damaged DNA and number of cells in G0/G1 phase were increased and S phase cells were decreased. Incubation with TRF reversed the morphology of senescent HDFs to resemble that of young cells with decreased activity of SA-β-gal, damaged DNA, and cells in G0/G1 phase while cells in the S phase were increased. Elongated telomere length and restoration of telomerase activity were observed in TRF-treated senescent HDFs. These findings confirmed the ability of tocotrienol-rich fraction in preventing HDFs cellular ageing by restoring telomere length and telomerase activity, reducing damaged DNA, and reversing cell cycle arrest associated with senescence.

  19. Squamocin modulates histone H3 phosphorylation levels and induces G1 phase arrest and apoptosis in cancer cells

    International Nuclear Information System (INIS)

    Histone modifications in tumorigenesis are increasingly recognized as important epigenetic factors leading to cancer. Increased phosphorylation levels of histone H3 as a result of aurora B and pMSK1 overexpression were observed in various tumors. We selected aurora B and MSK1 as representatives for testing various compounds and drugs, and found that squamocin, a bis-tetrahydrofuran annonaceous acetogenin, exerted a potent effect on histone H3 phosphorylation. GBM8401, Huh-7, and SW620 cells were incubated with 15, 30, and 60 μM squamocin for 24 h. The expressions of mRNA and proteins were analyzed by qRT-PCR and Western blotting, respectively. The cell viability was determined by an MTT assay. Cell cycle distribution and apoptotic cells were analyzed by flow cytometry. Our results showed that squamocin inhibited the proliferation of GBM8401, Huh-7, and SW620 cells, arrested the cell cycle at the G1 phase, and activated both intrinsic and extrinsic pathways to apoptosis. In addition, we demonstrated that squamocin had the ability to modulate the phosphorylation levels of H3S10 (H3S10p) and H3S28 (H3S28p) in association with the downregulation of aurora B and pMSK1 expressions. This study is the first to show that squamocin affects epigenetic alterations by modulating histone H3 phosphorylation at S10 and S28, providing a novel view of the antitumor mechanism of squamocin

  20. Ethanol Extract of Abnormal Savda Munziq, a Herbal Preparation of Traditional Uighur Medicine, Inhibits Caco-2 Cells Proliferation via Cell Cycle Arrest and Apoptosis

    Directory of Open Access Journals (Sweden)

    Abdiryim Yusup

    2012-01-01

    Full Text Available Aims. Study the effect of Abnormal Savda Munziq (ASMq ethanol extract on the proliferation, apoptosis, and correlative gene, expression in colon cancer cells (Caco-2 to elucidate the molecular mechanisms responsible for the anticancer property of Abnormal Savda Munziq. Materials and Methods. ASMq ethanol extract was prepared by a professional pharmacist. Caco-2 cells were treated with different concentration of ASMq ethanol extract (0.5–7.5 mg/mL for different time intervals (48 and 72 h. Antiproliferative effect of ASMq ethanol extract was determined by MTT assay; DNA fragmentation was determined by gel electrophoresis assay; cell cycle analysis was detected by flow cytometer; apoptosis-related gene expression was detected by RT-PCR assay. Results. ASMq ethanol extract possesses an inhibition effect on Caco-2 cells proliferation, induction of cell apoptosis, cell cycle arrest in sub-G1 phase, and downregulation of bcl-2 and upregulation of Bax gene expression. Conclusion. The anticancer mechanism of ASMq ethanol extract may be involved in antiproliferation, induction of apoptosis, cell cycle arrest, and regulation of apoptosis-related gene expression such as bcl-2 and Bax activity pathway.

  1. Ganoderic acid DM, a natural triterpenoid, induces DNA damage, G1 cell cycle arrest and apoptosis in human breast cancer cells.

    Science.gov (United States)

    Wu, Guo-Sheng; Lu, Jin-Jian; Guo, Jia-Jie; Li, Ying-Bo; Tan, Wen; Dang, Yuan-Ye; Zhong, Zhang-Feng; Xu, Zeng-Tao; Chen, Xiu-Ping; Wang, Yi-Tao

    2012-03-01

    Ganoderic acid DM (GADM) is a triterpenoid isolated from Ganoderma lucidum, a well-known edible medicinal mushroom. In the present study, we found that GADM effectively inhibited cell proliferation and colony formation in MCF-7 human breast cancer cells, which was much stronger than that of MDA-MB-231 breast cancer cells. GADM both concentration- and time-dependently mediated G1 cell cycle arrest and significantly decreased the protein level of CDK2, CDK6, cycle D1, p-Rb and c-Myc in MCF-7 cells. Moreover, GADM obviously induced DNA fragmentation and cleavage of PARP which are the characteristics of apoptosis and decreased the mitochondrial membrane potential in MCF-7 cells. Besides, we also showed that GADM elicited DNA damage as measured by comet assay which is a sensitive method for DNA damage detection. γ-H2AX, a marker of DNA damage, was also slightly up-regulated after treated with GADM for 6h, suggesting that the G1 cell cycle arrest and apoptosis induced by GADM may be partially resulted from GADM-induced DNA damage. These results have advanced our current understandings of the anti-cancer mechanisms of GADM. PMID:22178684

  2. Characterization of the N-methoxyindole-3-carbinol (NI3C)–Induced Cell Cycle Arrest in Human Colon Cancer Cell Lines

    DEFF Research Database (Denmark)

    Neave, Antje S.; Sarup, Sussi; Seidelin, Michel; Duus, Fritz; Vang, Ole

    2005-01-01

    study was to show the effect of NI3C on cell growth of two human colon cancer cell lines, DLD-1 and HCT-116. For the first time it is shown that NI3C inhibits cellular growth of DLD-1 and HCT-116 and that NI3C is a more potent inhibitor of cell proliferation than I3C. In addition to the inhibition of...... cellular proliferation, NI3C caused an accumulation of HCT-116 cells in the G2/M phase, in contrast to I3C, which led to an accumulation of the colon cells in G0/G1 phase. Furthermore, NI3C delays the G1-S phase transition of synchronized HCT-116 cells. The indole-mediated cell-cycle arrest may be related...

  3. Selenium Inhibits Metastasis of Murine Melanoma Cells through the Induction of Cell Cycle Arrest and Cell Death

    OpenAIRE

    SONG, HYUNKEUN; Hur, Indo; Park, Hyun-jin; Nam, Joohyung; PARK, GA BIN; Kong, Kyoung Hye; Hwang, Young Mi; KIM, YEONG SEOK; Cho, Dae Ho; Lee, Wang Jae; Hur, Dae Young

    2009-01-01

    Background Melanoma is the most fatal form of skin cancer due to its rapid metastasis. Recently, several studies reported that selenium can induce apoptosis in melanoma cells. However, the precise mechanism remains to be elucidated. In this study, we investigated the effect of selenium on cell proliferation in murine melanoma and on tumor growth and metastasis in C57BL/6 mice. Methods Cell proliferation was measured by MTT assay in selenium-treated melanoma cells. Cell cycle distribution was ...

  4. A sex-inducing pheromone triggers cell cycle arrest and mate attraction in the diatom Seminavis robusta.

    Science.gov (United States)

    Moeys, Sara; Frenkel, Johannes; Lembke, Christine; Gillard, Jeroen T F; Devos, Valerie; Van den Berge, Koen; Bouillon, Barbara; Huysman, Marie J J; De Decker, Sam; Scharf, Julia; Bones, Atle; Brembu, Tore; Winge, Per; Sabbe, Koen; Vuylsteke, Marnik; Clement, Lieven; De Veylder, Lieven; Pohnert, Georg; Vyverman, Wim

    2016-01-01

    Although sexual reproduction is believed to play a major role in the high diversification rates and species richness of diatoms, a mechanistic understanding of diatom life cycle control is virtually lacking. Diatom sexual signalling is controlled by a complex, yet largely unknown, pheromone system. Here, a sex-inducing pheromone (SIP(+)) of the benthic pennate diatom Seminavis robusta was identified by comparative metabolomics, subsequently purified, and physicochemically characterized. Transcriptome analysis revealed that SIP(+) triggers the switch from mitosis-to-meiosis in the opposing mating type, coupled with the transcriptional induction of proline biosynthesis genes, and the release of the proline-derived attraction pheromone. The induction of cell cycle arrest by a pheromone, chemically distinct from the one used to attract the opposite mating type, highlights the existence of a sophisticated mechanism to increase chances of mate finding, while keeping the metabolic losses associated with the release of an attraction pheromone to a minimum. PMID:26786712

  5. NBM-T-BBX-OS01, Semisynthesized from Osthole, Induced G1 Growth Arrest through HDAC6 Inhibition in Lung Cancer Cells.

    Science.gov (United States)

    Pai, Jih-Tung; Hsu, Chia-Yun; Hua, Kuo-Tai; Yu, Sheng-Yung; Huang, Chung-Yang; Chen, Chia-Nan; Liao, Chiung-Ho; Weng, Meng-Shih

    2015-01-01

    Disrupting lung tumor growth via histone deacetylases (HDACs) inhibition is a strategy for cancer therapy or prevention. Targeting HDAC6 may disturb the maturation of heat shock protein 90 (Hsp90) mediated cell cycle regulation. In this study, we demonstrated the effects of semisynthesized NBM-T-BBX-OS01 (TBBX) from osthole on HDAC6-mediated growth arrest in lung cancer cells. The results exhibited that the anti-proliferative activity of TBBX in numerous lung cancer cells was more potent than suberoylanilide hydroxamic acid (SAHA), a clinically approved pan-HDAC inhibitor, and the growth inhibitory effect has been mediated through G1 growth arrest. Furthermore, the protein levels of cyclin D1, CDK2 and CDK4 were reduced while cyclin E and CDK inhibitor, p21Waf1/Cip1, were up-regulated in TBBX-treated H1299 cells. The results also displayed that TBBX inhibited HDAC6 activity via down-regulation HDAC6 protein expression. TBBX induced Hsp90 hyper-acetylation and led to the disruption of cyclin D1/Hsp90 and CDK4/Hsp90 association following the degradation of cyclin D1 and CDK4 proteins through proteasome. Ectopic expression of HDAC6 rescued TBBX-induced G1 arrest in H1299 cells. Conclusively, the data suggested that TBBX induced G1 growth arrest may mediate HDAC6-caused Hsp90 hyper-acetylation and consequently increased the degradation of cyclin D1 and CDK4. PMID:25946558

  6. Genome-wide screen identifies novel machineries required for both ciliogenesis and cell cycle arrest upon serum starvation.

    Science.gov (United States)

    Kim, Ji Hyun; Ki, Soo Mi; Joung, Je-Gun; Scott, Eric; Heynen-Genel, Susanne; Aza-Blanc, Pedro; Kwon, Chang Hyuk; Kim, Joon; Gleeson, Joseph G; Lee, Ji Eun

    2016-06-01

    Biogenesis of the primary cilium, a cellular organelle mediating various signaling pathways, is generally coordinated with cell cycle exit/re-entry. Although the dynamic cell cycle-associated profile of the primary cilium has been largely accepted, the mechanism governing the link between ciliogenesis and cell cycle progression has been poorly understood. Using a human genome-wide RNAi screen, we identify genes encoding subunits of the spliceosome and proteasome as novel regulators of ciliogenesis. We demonstrate that 1) the mRNA processing-related hits are essential for RNA expression of molecules acting in cilia disassembly, such as AURKA and PLK1, and 2) the ubiquitin-proteasome systems (UPS)-involved hits are necessary for proteolysis of molecules acting in cilia assembly, such as IFT88 and CPAP. In particular, we show that these screen hit-associated mechanisms are crucial for both cilia assembly and cell cycle arrest in response to serum withdrawal. Finally, our data suggest that the mRNA processing mechanism may modulate the UPS-dependent decay of cilia assembly regulators to control ciliary resorption-coupled cell cycle re-entry. PMID:27033521

  7. Antitumoral activity of the mithralog EC-8042 in triple negative breast cancer linked to cell cycle arrest in G2.

    Science.gov (United States)

    Pandiella, Atanasio; Morís, Francisco; Ocaña, Alberto; Núñez, Luz-Elena; Montero, Juan C

    2015-10-20

    Triple negative breast cancer (TNBC) is an aggressive form of breast cancer. Despite response to chemotherapy, relapses are frequent and resistance to available treatments is often observed in the metastatic setting. Therefore, identification of new therapeutic strategies is required. Here we have investigated the effect of the mithramycin analog EC-8042 (demycarosil-3D-β-D-digitoxosyl mithramycin SK) on TNBC. The drug caused a dose-dependent inhibition of proliferation of a set of TNBC cell lines in vitro, and decreased tumor growth in mice xenografted with TNBC cells. Mechanistically, EC-8042 caused an arrest in the G2 phase of the cell cycle, coincident with an increase in pCDK1 and Wee1 levels in cells treated with the drug. In addition, prolonged treatment with the drug also causes apoptosis, mainly through caspase-independent routes. Importantly, EC-8042 synergized with drugs commonly used in the therapy of TNBC in vitro, and potentiated the antitumoral effect of docetaxel in vivo. Together, these data suggest that the mithralog EC-8042 exerts an antitumoral action on TNBC cells and reinforces the action of standard of care drugs used in the therapy of this disease. These characteristics, together with a better toxicology profile of EC-8042 with respect to mithramycin, open the possibility of its clinical evaluation. PMID:26439989

  8. CFS-1686 causes cell cycle arrest at intra-S phase by interference of interaction of topoisomerase 1 with DNA.

    Directory of Open Access Journals (Sweden)

    Ru-Wei Lin

    Full Text Available CFS-1686 (chemical name (E-N-(2-(diethylaminoethyl-4-(2-(2-(5-nitrofuran-2-ylvinylquinolin-4-ylaminobenzamide inhibits cell proliferation and triggers late apoptosis in prostate cancer cell lines. Comparing the effect of CFS-1686 on cell cycle progression with the topoisomerase 1 inhibitor camptothecin revealed that CFS-1686 and camptothecin reduced DNA synthesis in S-phase, resulting in cell cycle arrest at the intra-S phase and G1-S boundary, respectively. The DNA damage in CFS-1686 and camptothecin treated cells was evaluated by the level of ATM phosphorylation, γH2AX, and γH2AX foci, showing that camptothecin was more effective than CFS-1686. However, despite its lower DNA damage capacity, CFS-1686 demonstrated 4-fold higher inhibition of topoisomerase 1 than camptothecin in a DNA relaxation assay. Unlike camptothecin, CFS-1686 demonstrated no activity on topoisomerase 1 in a DNA cleavage assay, but nevertheless it reduced the camptothecin-induced DNA cleavage of topoisomerase 1 in a dose-dependent manner. Our results indicate that CFS-1686 might bind to topoisomerase 1 to inhibit this enzyme from interacting with DNA relaxation activity, unlike campothecin's induction of a topoisomerase 1-DNA cleavage complex. Finally, we used a computer docking strategy to localize the potential binding site of CFS-1686 to topoisomerase 1, further indicating that CFS-1686 might inhibit the binding of Top1 to DNA.

  9. Expression of 1N3R-Tau isoform inhibits cell proliferation by inducing S phase arrest in N2a cells.

    Directory of Open Access Journals (Sweden)

    Li Li

    Full Text Available Tau is a microtubule-associated protein implicated in neurodegenerative tauopathies. Six tau isoforms are generated from a single gene through alternative splicing of exons 2, 3 and 10 in human brain. Differential expression of tau isoforms has been detected in different brain areas, during neurodevelopment and in neurodegenerative disorders. However, the biological significance of different tau isoforms is not clear. Here, we investigated the individual effect of six different isoforms of tau on cell proliferation and the possible mechanisms by transient expression of eGFP-labeled tau isoform plasmid in N2a cells. Our study showed the transfection efficiency was comparable between different isoforms of tau by examining GFP expression. Compared with other isoforms, we found expression of 1N3R-tau significantly inhibited cell proliferation by Cell Counting Kit-8 assay and BrdU incorporation. Flow cytometry analysis further showed expression of 1N3R-tau induced S phase arrest. Compared with the longest isoform of tau, expression of 1N3R-tau induced cyclin E translocation from the nuclei to cytoplasm, while it did not change the level of cell cycle checkpoint proteins. These data indicate that 1N3R-tau inhibits cell proliferation through inducing S phase arrest.

  10. A phthalide derivative isolated from endophytic fungi Pestalotiopsis photiniae induces G1 cell cycle arrest and apoptosis in human HeLa cells

    Directory of Open Access Journals (Sweden)

    C. Chen

    2013-08-01

    Full Text Available MP [4-(3′,3′-dimethylallyloxy-5-methyl-6-methoxyphthalide] was obtained from liquid culture of Pestalotiopsis photiniae isolated from the Chinese Podocarpaceae plant Podocarpus macrophyllus. MP significantly inhibited the proliferation of HeLa tumor cell lines. After treatment with MP, characteristic apoptotic features such as DNA fragmentation and chromatin condensation were observed in DAPI-stained HeLa cells. Flow cytometry showed that MP induced G1 cell cycle arrest and apoptosis in a dose-dependent manner. Western blotting and real-time reverse transcription-polymerase chain reaction were used to investigate protein and mRNA expression. MP caused significant cell cycle arrest by upregulating the cyclin-dependent kinase inhibitor p27KIP1 protein and p21CIP1 mRNA levels in HeLa cells. The expression of p73 protein was increased after treatment with various MP concentrations. mRNA expression of the cell cycle-related genes, p21CIP1 , p16INK4a and Gadd45α, was significantly upregulated and mRNA levels demonstrated significantly increased translation of p73, JunB, FKHR, and Bim. The results indicate that MP may be a potential treatment for cervical cancer.

  11. A phthalide derivative isolated from endophytic fungi Pestalotiopsis photiniae induces G1 cell cycle arrest and apoptosis in human HeLa cells

    Energy Technology Data Exchange (ETDEWEB)

    Chen, C. [College of Life Science, Hebei University, Baoding (China); Yang, R.L. [Key Laboratory of Microbial Diversity Research and Application of Hebei Province, Baoding, China, Key Laboratory of Microbial Diversity Research and Application of Hebei Province, Baoding (China)

    2013-07-30

    MP [4-(3′,3′-dimethylallyloxy)-5-methyl-6-methoxyphthalide] was obtained from liquid culture of Pestalotiopsis photiniae isolated from the Chinese Podocarpaceae plant Podocarpus macrophyllus. MP significantly inhibited the proliferation of HeLa tumor cell lines. After treatment with MP, characteristic apoptotic features such as DNA fragmentation and chromatin condensation were observed in DAPI-stained HeLa cells. Flow cytometry showed that MP induced G1 cell cycle arrest and apoptosis in a dose-dependent manner. Western blotting and real-time reverse transcription-polymerase chain reaction were used to investigate protein and mRNA expression. MP caused significant cell cycle arrest by upregulating the cyclin-dependent kinase inhibitor p27{sup KIP1} protein and p21{sup CIP1} mRNA levels in HeLa cells. The expression of p73 protein was increased after treatment with various MP concentrations. mRNA expression of the cell cycle-related genes, p21{sup CIP1}, p16{sup INK4a} and Gadd45α, was significantly upregulated and mRNA levels demonstrated significantly increased translation of p73, JunB, FKHR, and Bim. The results indicate that MP may be a potential treatment for cervical cancer.

  12. A phthalide derivative isolated from endophytic fungi Pestalotiopsis photiniae induces G1 cell cycle arrest and apoptosis in human HeLa cells

    International Nuclear Information System (INIS)

    MP [4-(3′,3′-dimethylallyloxy)-5-methyl-6-methoxyphthalide] was obtained from liquid culture of Pestalotiopsis photiniae isolated from the Chinese Podocarpaceae plant Podocarpus macrophyllus. MP significantly inhibited the proliferation of HeLa tumor cell lines. After treatment with MP, characteristic apoptotic features such as DNA fragmentation and chromatin condensation were observed in DAPI-stained HeLa cells. Flow cytometry showed that MP induced G1 cell cycle arrest and apoptosis in a dose-dependent manner. Western blotting and real-time reverse transcription-polymerase chain reaction were used to investigate protein and mRNA expression. MP caused significant cell cycle arrest by upregulating the cyclin-dependent kinase inhibitor p27KIP1 protein and p21CIP1 mRNA levels in HeLa cells. The expression of p73 protein was increased after treatment with various MP concentrations. mRNA expression of the cell cycle-related genes, p21CIP1, p16INK4a and Gadd45α, was significantly upregulated and mRNA levels demonstrated significantly increased translation of p73, JunB, FKHR, and Bim. The results indicate that MP may be a potential treatment for cervical cancer

  13. Evaluation of biomarkers of cell cycle arrest and inflammation in prediction of dialysis or recovery after kidney transplantation.

    Science.gov (United States)

    Pianta, Timothy J; Peake, Philip W; Pickering, John W; Kelleher, Michaela; Buckley, Nicholas A; Endre, Zoltan H

    2015-12-01

    Early prediction of delayed graft function (DGF) after kidney transplantation would facilitate patient management. Cell cycle arrest and inflammation are implicated in the pathogenesis of DGF. We assessed the utility of two novel acute kidney injury (AKI) biomarkers, urinary tissue inhibitor of metalloproteinases-2 (TIMP-2) and insulin-like growth factor-binding protein 7 (IGFBP7), and five inflammatory markers to predict DGF following deceased-donor kidney transplantation. Serial urine concentrations of TIMP-2 and IGFBP7 were measured immediately after transplantation in 56 recipients along with vascular endothelial growth factor-A (VEGF-A), macrophage migration inhibitory factor (MIF), monocyte chemotactic protein-1 (MCP-1), trefoil factor 3 (TFF3) and chemokine (C-X-C) ligand 16 (CXCL16). Delayed graft function (DGF) was defined as requirement for dialysis within 7 days. Integrated discrimination improvement analysis was used to evaluate whether these biomarkers enhanced prediction of DGF independently of a validated clinical risk prediction model. DGF occurred in 22 patients (39%). At 4 h after kidney reperfusion, the area under the receiver operator characteristic curve (AUC) for VEGF-A was good (AUC > 0.80); for TIMP-2, IGFBP7 and [TIMP-2] × [IGFBP7] fair (AUCs 0.70-0.79); and for MIF, MCP-1, TFF3 and CXCL16 poor (AUC < 0.70). Only TIMP-2 and VEGF significantly enhanced the DGF prediction at 4 and 12 h. The cell cycle arrest marker urinary TIMP-2 and the inflammatory biomarker VEGF-A are potentially useful adjuncts to clinical data for early prediction of DGF. PMID:26174580

  14. Adenosine induces cell cycle arrest and apoptosis via cyclinD1/Cdk4 and Bcl-2/Bax pathways in human ovarian cancer cell line OVCAR-3.

    Science.gov (United States)

    Shirali, Saeid; Aghaei, Mahmoud; Shabani, Mahdi; Fathi, Mojtaba; Sohrabi, Majid; Moeinifard, Marzieh

    2013-04-01

    Adenosine is a regulatory molecule with widespread physiological effects in almost every cells and acts as a potent regulator of cell growth. Adenosine has been shown to inhibit cell growth and induce apoptosis in the several cancer cells via caspase activation and Bcl-2/Bax pathway. The present study was designed to understand the mechanism underlying adenosine-induced apoptosis in the OVCAR-3 human ovarian cancer cells. MTT viability, BrdU and cell counting assays were used to study the cell proliferation effect of adenosine in presence of adenosine deaminase inhibitor and the nucleoside transporter inhibitor. Cell cycle analysis, propidium iodide and annexin V staining, caspase-3 activity assay, cyclinD1, Cdk4, Bcl-2 and Bax protein expressions were assessed to detect apoptosis. Adenosine significantly inhibited cell proliferation in a concentration-dependent manner in OVCAR-3 cell line. Adenosine induced cell cycle arrest in G0/G1 phase via Cdk4/cyclinD1-mediated pathway. Adenosine induced apoptosis, which was determined by Annexin V-FITC staining and increased sub-G1 population. Moreover, down-regulation of Bcl-2 protein expression, up-regulation of Bax protein expression and activation of caspase-3 were observed in response to adenosine treatment. The results of this study suggest that extracellular adenosine induced G1 cell cycle arrest and apoptosis in ovarian cancer cells via cyclinD1/ Cdk4 and Bcl-2/Bax pathways and caspase-3 activation. These data might suggest that adenosine could be used as an agent for the treatment of ovarian cancer. PMID:23345014

  15. A novel muscarinic antagonist R2HBJJ inhibits non-small cell lung cancer cell growth and arrests the cell cycle in G0/G1.

    Directory of Open Access Journals (Sweden)

    Nan Hua

    Full Text Available Lung cancers express the cholinergic autocrine loop, which facilitates the progression of cancer cells. The antagonists of mAChRs have been demonstrated to depress the growth of small cell lung cancers (SCLCs. In this study we intended to investigate the growth inhibitory effect of R2HBJJ, a novel muscarinic antagonist, on non-small cell lung cancer (NSCLC cells and the possible mechanisms. The competitive binding assay revealed that R2HBJJ had a high affinity to M3 and M1 AChRs. R2HBJJ presented a strong anticholinergic activity on carbachol-induced contraction of guinea-pig trachea. R2HBJJ markedly suppressed the growth of NSCLC cells, such as H1299, H460 and H157. In H1299 cells, both R2HBJJ and its leading compound R2-PHC displayed significant anti-proliferative activity as M3 receptor antagonist darifenacin. Exogenous replenish of ACh could attenuate R2HBJJ-induced growth inhibition. Silencing M3 receptor or ChAT by specific-siRNAs resulted in a growth inhibition of 55.5% and 37.9% on H1299 cells 96 h post transfection, respectively. Further studies revealed that treatment with R2HBJJ arrested the cell cycle in G0/G1 by down-regulation of cyclin D1-CDK4/6-Rb. Therefore, the current study reveals that NSCLC cells express an autocrine and paracrine cholinergic system which stimulates the growth of NSCLC cells. R2HBJJ, as a novel mAChRs antagonist, can block the local cholinergic loop by antagonizing predominantly M3 receptors and inhibit NSCLC cell growth, which suggest that M3 receptor antagonist might be a potential chemotherapeutic regimen for NSCLC.

  16. A novel muscarinic antagonist R2HBJJ inhibits non-small cell lung cancer cell growth and arrests the cell cycle in G0/G1.

    Science.gov (United States)

    Hua, Nan; Wei, Xiaoli; Liu, Xiaoyan; Ma, Xiaoyun; He, Xinhua; Zhuo, Rengong; Zhao, Zhe; Wang, Liyun; Yan, Haitao; Zhong, Bohua; Zheng, Jianquan

    2012-01-01

    Lung cancers express the cholinergic autocrine loop, which facilitates the progression of cancer cells. The antagonists of mAChRs have been demonstrated to depress the growth of small cell lung cancers (SCLCs). In this study we intended to investigate the growth inhibitory effect of R2HBJJ, a novel muscarinic antagonist, on non-small cell lung cancer (NSCLC) cells and the possible mechanisms. The competitive binding assay revealed that R2HBJJ had a high affinity to M3 and M1 AChRs. R2HBJJ presented a strong anticholinergic activity on carbachol-induced contraction of guinea-pig trachea. R2HBJJ markedly suppressed the growth of NSCLC cells, such as H1299, H460 and H157. In H1299 cells, both R2HBJJ and its leading compound R2-PHC displayed significant anti-proliferative activity as M3 receptor antagonist darifenacin. Exogenous replenish of ACh could attenuate R2HBJJ-induced growth inhibition. Silencing M3 receptor or ChAT by specific-siRNAs resulted in a growth inhibition of 55.5% and 37.9% on H1299 cells 96 h post transfection, respectively. Further studies revealed that treatment with R2HBJJ arrested the cell cycle in G0/G1 by down-regulation of cyclin D1-CDK4/6-Rb. Therefore, the current study reveals that NSCLC cells express an autocrine and paracrine cholinergic system which stimulates the growth of NSCLC cells. R2HBJJ, as a novel mAChRs antagonist, can block the local cholinergic loop by antagonizing predominantly M3 receptors and inhibit NSCLC cell growth, which suggest that M3 receptor antagonist might be a potential chemotherapeutic regimen for NSCLC. PMID:23285263

  17. (4-Methoxyphenyl)(3,4,5-trimethoxyphenyl)methanone inhibits tubulin polymerization, induces G2/M arrest, and triggers apoptosis in human leukemia HL-60 cells

    International Nuclear Information System (INIS)

    (4-Methoxyphenyl)(3,4,5-trimethoxyphenyl)methanone (PHT) is a known cytotoxic compound belonging to the phenstatin family. However, the exact mechanism of action of PHT-induced cell death remains to be determined. The aim of this study was to investigate the mechanisms underlying PHT-induced cytotoxicity. We found that PHT displayed potent cytotoxicity in different tumor cell lines, showing IC50 values in the nanomolar range. Cell cycle arrest in G2/M phase along with the augmented metaphase cells was found. Cells treated with PHT also showed typical hallmarks of apoptosis such as cell shrinkage, chromatin condensation, phosphatidylserine exposure, increase of the caspase 3/7 and 8 activation, loss of mitochondrial membrane potential, and internucleosomal DNA fragmentation without affecting membrane integrity. Studies conducted with isolated tubulin and docking models confirmed that PHT binds to the colchicine site and interferes in the polymerization of microtubules. These results demonstrated that PHT inhibits tubulin polymerization, arrests cancer cells in G2/M phase of the cell cycle, and induces their apoptosis, exhibiting promising anticancer therapeutic potential. - Highlights: • PHT inhibits tubulin polymerization. • PHT arrests cancer cells in G2/M phase of the cell cycle. • PHT induces caspase-dependent apoptosis

  18. (4-Methoxyphenyl)(3,4,5-trimethoxyphenyl)methanone inhibits tubulin polymerization, induces G{sub 2}/M arrest, and triggers apoptosis in human leukemia HL-60 cells

    Energy Technology Data Exchange (ETDEWEB)

    Magalhães, Hemerson I.F. [Departamento de Fisiologia e Farmacologia, Faculdade de Medicina, Universidade Federal do Ceará, Fortaleza, Ceará (Brazil); Centro de Ciências da Saúde, Departamento de Ciências Farmacêuticas, Universidade Federal da Paraíba, João Pessoa, Paraíba (Brazil); Wilke, Diego V. [Departamento de Fisiologia e Farmacologia, Faculdade de Medicina, Universidade Federal do Ceará, Fortaleza, Ceará (Brazil); Bezerra, Daniel P., E-mail: danielpbezerra@gmail.com [Centro de Pesquisa Gonçalo Moniz, Fundação Oswaldo Cruz, Salvador, Bahia (Brazil); Cavalcanti, Bruno C. [Departamento de Fisiologia e Farmacologia, Faculdade de Medicina, Universidade Federal do Ceará, Fortaleza, Ceará (Brazil); Rotta, Rodrigo; Lima, Dênis P. de; Beatriz, Adilson [Centro de Ciências Exatas e Tecnológicas (Laboratório LP4), Universidade Federal do Mato Grosso do Sul, Campo Grande, Mato Grosso do Sul (Brazil); Moraes, Manoel O.; Diniz-Filho, Jairo [Departamento de Fisiologia e Farmacologia, Faculdade de Medicina, Universidade Federal do Ceará, Fortaleza, Ceará (Brazil); Pessoa, Claudia, E-mail: c_pessoa@yahoo.com [Departamento de Fisiologia e Farmacologia, Faculdade de Medicina, Universidade Federal do Ceará, Fortaleza, Ceará (Brazil)

    2013-10-01

    (4-Methoxyphenyl)(3,4,5-trimethoxyphenyl)methanone (PHT) is a known cytotoxic compound belonging to the phenstatin family. However, the exact mechanism of action of PHT-induced cell death remains to be determined. The aim of this study was to investigate the mechanisms underlying PHT-induced cytotoxicity. We found that PHT displayed potent cytotoxicity in different tumor cell lines, showing IC{sub 50} values in the nanomolar range. Cell cycle arrest in G{sub 2}/M phase along with the augmented metaphase cells was found. Cells treated with PHT also showed typical hallmarks of apoptosis such as cell shrinkage, chromatin condensation, phosphatidylserine exposure, increase of the caspase 3/7 and 8 activation, loss of mitochondrial membrane potential, and internucleosomal DNA fragmentation without affecting membrane integrity. Studies conducted with isolated tubulin and docking models confirmed that PHT binds to the colchicine site and interferes in the polymerization of microtubules. These results demonstrated that PHT inhibits tubulin polymerization, arrests cancer cells in G{sub 2}/M phase of the cell cycle, and induces their apoptosis, exhibiting promising anticancer therapeutic potential. - Highlights: • PHT inhibits tubulin polymerization. • PHT arrests cancer cells in G{sub 2}/M phase of the cell cycle. • PHT induces caspase-dependent apoptosis.

  19. 7-Epiclusianone, a Benzophenone Extracted from Garcinia brasiliensis (Clusiaceae, Induces Cell Cycle Arrest in G1/S Transition in A549 Cells

    Directory of Open Access Journals (Sweden)

    Marisa Ionta

    2015-07-01

    Full Text Available Lung cancer is the leading cause of cancer deaths in the world. Disease stage is the most relevant factor influencing mortality. Unfortunately, most patients are still diagnosed at an advanced stage and their five-year survival rate is only 4%. Thus, it is relevant to identify novel drugs that can improve the treatment options for lung cancer. Natural products have been an important source for the discovery of new compounds with pharmacological potential including antineoplastic agents. We have previously isolated a prenylated benzophenone (7-epiclusianone from Garcinia brasiliensis (Clusiaceae that has several biological properties including antiproliferative activity against cancer cell lines. In continuation with our studies, the present work aimed to investigate the mechanisms involved with antiproliferative activity of 7-epiclusianone in A549 cells. Our data showed that 7-epiclusianone reduced the viability of A549 cells in a concentration-dependent manner (IC50 of 16.13 ± 1.12 μM. Cells were arrested in G1/S transition and apoptosis was induced. In addition, we observed morphological changes with cytoskeleton disorganization in consequence of the treatment. Taken together, the results showed that cell cycle arrest in G1/S transition is the main mechanism involved with antiproliferative activity of 7-epiclusianone. Our results are promising and open up the prospect of using this compound in further anticancer in vivo studies.

  20. Airborne urban particles (Milan winter-PM2.5) cause mitotic arrest and cell death: Effects on DNA, mitochondria, AhR binding and spindle organization

    International Nuclear Information System (INIS)

    Highlights: → PM2.5 induces mitotic arrest in BEAS-2B cells. → PM2.5 induces DNA damage and activates DNA damage response. → AhR regulated genes (Cyp1A1, Cyp1B1 and AhRR) are upregulated after PM exposure. → Mitotic spindle assembly is perturbed in PM exposed cells. - Abstract: Airborne particulate matter (PM) is considered to be an important contributor to lung diseases. In the present study we report that Milan winter-PM2.5 inhibited proliferation in human bronchial epithelial cells (BEAS-2B) by inducing mitotic arrest. The cell cycle arrest was followed by an increase in mitotic-apoptotic cells, mitotic slippage and finally an increase in 'classical' apoptotic cells. Exposure to winter-PM10 induced only a slight effect which may be due to the presence of PM2.5 in this fraction while pure combustion particles failed to disturb mitosis. Fewer cells expressing the mitosis marker phospho-histone H3 compared to cells with condensed chromosomes, suggest that PM2.5 induced premature mitosis. PM2.5 was internalized into the cells and often localized in laminar organelles, although particles without apparent plasma membrane covering were also seen. In PM-containing cells mitochondria and lysosomes were often damaged, and in mitotic cells fragmented chromosomes often appeared. PM2.5 induced DNA strands breaks and triggered a DNA-damage response characterized by increased phosphorylation of ATM, Chk2 and H2AX; as well as induced a marked increase in expression of the aryl hydrocarbon receptor (AhR)-regulated genes, CYP1A1, CYP1B1 and AhRR. Furthermore, some disturbance of the organization of microtubules was indicated. It is hypothesized that the induced mitotic arrest and following cell death was due to a premature chromosome condensation caused by a combination of DNA, mitochondrial and spindle damage.

  1. Human cytochrome c enters murine J774 cells and causes G1 and G2/M cell cycle arrest and induction of apoptosis

    International Nuclear Information System (INIS)

    Cytochrome c is well known as a carrier of electrons during respiration. Current evidence indicates that cytochrome c also functions as a major component of apoptosomes to induce apoptosis in eukaryotic cells as well as an antioxidant. More recently, a prokaryotic cytochrome c, cytochrome c 551 from Pseudomonas aeruginosa, has been shown to enter in mammalian cells such as the murine macrophage-like J774 cells and causes inhibition of cell cycle progression. Much less is known about such functions by mammalian cytochromes c, particularly the human cytochrome c. We now report that similar to P. aeruginosa cytochrome c 551, the purified human cytochrome c protein can enter J774 cells and induce cell cycle arrest at the G1 to S phase, as well as at the G2/M phase at higher concentrations. Unlike P. aeruginosa cytochrome c 551 which had no effect on the induction of apoptosis, human cytochrome c induces significant apoptosis and cell death in J774 cells, presumably through inhibition of the cell cycle at the G2/M phase. When incubated with human breast cancer MCF-7 and normal mammary epithelial cell line MCF-10A1 cells, human cytochrome c entered in both types of cells but induced cell death only in the normal MCF-10A1 cells. The ability of human cytochrome c to enter J774 cells was greatly reduced at 4 deg. C, suggesting energy requirement in the entry process

  2. Tris(2-chloroethyl)phosphate-induced cell growth arrest via attenuation of SIRT1-independent PI3K/Akt/mTOR pathway.

    Science.gov (United States)

    Zhang, Wenjuan; Zhang, Youjian; Wang, Zhiyuan; Xu, Tian; Huang, Cheng; Yin, Wenjun; Wang, Jing; Xiong, Wei; Lu, Wenhong; Zheng, Hongyan; Yuan, Jing

    2016-07-01

    Tris(2-chloroethyl)phosphate (TCEP) as an organophosphorus flame retardant and plasticizer has been widely used in industrial and household products. It not only was detected in residential indoor air and dust, surface and drinking water, but also in human plasma and breast milk, and tissue samples of liver, kidneys and brain from rodents. TCEP is classified as carcinogenic category 2 and toxic for reproduction category 1B. Sufficient evidence from experimental animals indicated carcinogenicity of TCEP in the liver, and kidneys as well as cell loss in the brain. However, the underlying mechanisms of TCEP-induced hepatotoxicity are mostly unknown. We investigated the in vitro effects of TCEP as well as TCEP-induced cell growth in the L02 and HepG2 cells through the PI3K/Akt/mTOR pathway. We found that TCEP reduced cell viability of these cell lines, induced the cell growth arrest, upregulated mRNA and protein levels of SIRT1, and attenuated the PI3K/Akt/mTOR pathway. However, growth arrest of the L02 and HepG2 cells were aggravated after inhibiting the SIRT1 expression with EX-527. The findings above suggested that TCEP induced the cell growth arrest of L02 and HepG2 cells via attenuation of the SIRT1-independent PI3K/Akt/mTOR pathway. Copyright © 2015 John Wiley & Sons, Ltd. PMID:26378621

  3. Curcumin inhibits the proliferation of a human colorectal cancer cell line Caco-2 partially by both apoptosis and G2/M cell cycle arrest

    Directory of Open Access Journals (Sweden)

    Yohko Fujimoto

    2014-06-01

    Full Text Available The aim of this study was to assess the possible roles of the phytochemical compounds, curcumin, quercetin and resveratrol in the proliferation of human colorectal cancer cell line Caco-2. All three phytochemical compounds inhibited Caco-2 cell proliferation, with curcumin being more effective than quercetin and resveratrol. Investigations concerning DNA fragmentation in the nucleus, Bax and Bcl-2 mRNA expression levels, and caspase-3/7 activity indicated that curcumin induced apoptosis in Caco-2 cells through an increase in the Bax/Bcl-2 ratio and activation of caspase-3/7. Furthermore, the analysis of flow-cytometry showed that curcumin caused an arrest of G2/M phase in Caco-2 cells. These results suggest that curcumin suppresses Caco-2 proliferation partially via activation of the mitochondrial apoptotic pathway and cell cycle retardation.

  4. Aloe emodin induces G2/M cell cycle arrest and apoptosis via activation of caspase-6 in human colon cancer cells.

    Science.gov (United States)

    Suboj, Priya; Babykutty, Suboj; Srinivas, Priya; Gopala, Srinivas

    2012-01-01

    Aloe emodin (AE), a natural anthraquinone, is reported to have antiproliferative activity in various cancer cell lines. In this study, we analyzed the molecular mechanisms involved in the growth-inhibitory activity of this hydroxyanthraquinone in colon cancer cell, WiDr. In our observation AE inhibited cell proliferation by arresting the cell cycle at the G2/M phase and inhibiting cyclin B1. AE appreciably induced cell death specifically through the induction of apoptosis and by activating caspases 9/6. Apoptotic execution was found to be solely dependent on caspase-6 rather than caspase-3 or caspase-7. This is the first study indicating that the AE induces apoptosis specifically through the activation of caspase-6. PMID:22343391

  5. Green synthesis of platinum nanoparticles that induce cell death and G2/M-phase cell cycle arrest in human cervical cancer cells.

    Science.gov (United States)

    Alshatwi, Ali A; Athinarayanan, Jegan; Vaiyapuri Subbarayan, Periasamy

    2015-01-01

    Platinum-based chemotherapeutic drugs, including cisplatin, carboplatin, and oxaliplatin, have been used to manage cancer in spite of dose-dependent side effects, including nephrotoxicity, neurotoxicity and ototoxicity. These disadvantages have prompted the development of new strategies for cancer therapy that utilize functionalized nanoparticles as nanomedicines. In the present investigation, we have synthesized platinum nanoparticles using tea polyphenol (TPP) as both a reducing and surface modifying agent. The crystalline nature and morphology of the prepared TPP-functionalized platinum nanoparticles (TPP@Pt) were analyzed using X-ray diffraction (XRD) and transmission electron microscopy (TEM). The XRD results revealed that the TPP@Pt had a crystalline nature with a face-centered cubic structure. TEM imaging suggested that the TTP@Pt are flower shaped with a well-dispersed 30-60 nm-sized TPP@Pt formation. Cervical cancer cells (SiHa) were then treated with different concentrations of TPP@Pt. The effects of TPP@Pt on cell viability, nuclear morphology and cell cycle distribution were investigated. A cell viability assay revealed that the proliferation of SiHa cells was inhibited by TPP@Pt. Propidium iodide nuclear staining indicated that TPP@Pt induced nuclear fragmentation and chromatin condensation. Treatment with TPP@Pt significantly increased the percentage of cells in the G2/M phase, which indicates induced cell cycle arrest in the G2/M phase and an increased number of cells in the subG0 cell death phase. These findings highlight a potential use of TPP@Pt in cervical cancer treatment. PMID:25577212

  6. LRD-22, a novel dual dithiocarbamatic acid ester, inhibits Aurora-A kinase and induces apoptosis and cell cycle arrest in HepG2 cells

    International Nuclear Information System (INIS)

    In this study we investigated the antitumor activity of the novel dual dithiocarbamatic acid ester LRD-22 in vitro and in vivo. Several cancer cell lines were employed to determine the effect of LRD-22 on cell growth, and the MTT assay showed there was a significant decrease in viable tumor cell numbers in the presence of LRD-22, especially in the HepG2 cell line. Colony formation assay also showed LRD-22 strongly inhibits HepG2 cell growth. Evaluation of the mechanism involved showed that inhibitory effects of LRD-22 on cell growth are due to induction of apoptosis and G2/M arrest. LRD-22 inhibited Aurora-A phosphorylation at Thr288 and subsequently impaired p53 phosphorylation at Ser315 which was associated with the proteasome degradation pathway. Tumor suppressor protein p53 is stabilized by this mechanism and accumulates through inhibition of Aurora-A kinase activity via treatment with LRD-22. In vivo study of HepG2 xenograft in nude mice also shows LRD-22 suppresses tumor growth at a concentration of 5 mg/kg without animals suffering loss of body weight. In conclusion, our results demonstrate LRD-22 acts as an Aurora-A kinase inhibitor to induce apoptosis and inhibit proliferation in HepG2 cells, and should be considered as a promising targeting agent for HCC therapy. - Highlights: • LRD-22 significantly inhibits cancer cell growth, especially in the HepG2 cell line. • The inhibitory effect of LRD-22 is due to induction of apoptosis and cell cycle arrest. • LRD-22 inhibits Aurora-A phosphorylation which results in subsequent impairment of the p53 pathway. • LRD-22 suppresses tumor growth in xenograft mice without body weight loss

  7. Metformin induces apoptosis and cell cycle arrest mediated by oxidative stress, AMPK and FOXO3a in MCF-7 breast cancer cells.

    Directory of Open Access Journals (Sweden)

    Eveline A I F Queiroz

    Full Text Available Recent studies have demonstrated that the anti-diabetic drug, metformin, can exhibit direct antitumoral effects, or can indirectly decrease tumor proliferation by improving insulin sensitivity. Despite these recent advances, the underlying molecular mechanisms involved in decreasing tumor formation are not well understood. In this study, we examined the antiproliferative role and mechanism of action of metformin in MCF-7 cancer cells treated with 10 mM of metformin for 24, 48, and 72 hours. Using BrdU and the MTT assay, it was found that metformin demonstrated an antiproliferative effect in MCF-7 cells that occurred in a time- and concentration-dependent manner. Flow cytometry was used to analyze markers of cell cycle, apoptosis, necrosis and oxidative stress. Exposure to metformin induced cell cycle arrest in G0-G1 phase and increased cell apoptosis and necrosis, which were associated with increased oxidative stress. Gene and protein expression were determined in MCF-7 cells by real time RT-PCR and western blotting, respectively. In MCF-7 cells metformin decreased the activation of IRβ, Akt and ERK1/2, increased p-AMPK, FOXO3a, p27, Bax and cleaved caspase-3, and decreased phosphorylation of p70S6K and Bcl-2 protein expression. Co-treatment with metformin and H2O2 increased oxidative stress which was associated with reduced cell number. In the presence of metformin, treating with SOD and catalase improved cell viability. Treatment with metformin resulted in an increase in p-p38 MAPK, catalase, MnSOD and Cu/Zn SOD protein expression. These results show that metformin has an antiproliferative effect associated with cell cycle arrest and apoptosis, which is mediated by oxidative stress, as well as AMPK and FOXO3a activation. Our study further reinforces the potential benefit of metformin in cancer treatment and provides novel mechanistic insight into its antiproliferative role.

  8. LRD-22, a novel dual dithiocarbamatic acid ester, inhibits Aurora-A kinase and induces apoptosis and cell cycle arrest in HepG2 cells

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Huiling; Li, Ridong [State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing (China); Li, Li [Department of Cell Biology, School of Basic Medical Sciences, Peking University, Beijing (China); Ge, Zemei [State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing (China); Zhou, Rouli, E-mail: rlzhou@bjmu.edu.cn [Department of Cell Biology, School of Basic Medical Sciences, Peking University, Beijing (China); Li, Runtao, E-mail: lirt@bjmu.edu.cn [State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing (China)

    2015-02-27

    In this study we investigated the antitumor activity of the novel dual dithiocarbamatic acid ester LRD-22 in vitro and in vivo. Several cancer cell lines were employed to determine the effect of LRD-22 on cell growth, and the MTT assay showed there was a significant decrease in viable tumor cell numbers in the presence of LRD-22, especially in the HepG2 cell line. Colony formation assay also showed LRD-22 strongly inhibits HepG2 cell growth. Evaluation of the mechanism involved showed that inhibitory effects of LRD-22 on cell growth are due to induction of apoptosis and G2/M arrest. LRD-22 inhibited Aurora-A phosphorylation at Thr{sub 288} and subsequently impaired p53 phosphorylation at Ser{sub 315} which was associated with the proteasome degradation pathway. Tumor suppressor protein p53 is stabilized by this mechanism and accumulates through inhibition of Aurora-A kinase activity via treatment with LRD-22. In vivo study of HepG2 xenograft in nude mice also shows LRD-22 suppresses tumor growth at a concentration of 5 mg/kg without animals suffering loss of body weight. In conclusion, our results demonstrate LRD-22 acts as an Aurora-A kinase inhibitor to induce apoptosis and inhibit proliferation in HepG2 cells, and should be considered as a promising targeting agent for HCC therapy. - Highlights: • LRD-22 significantly inhibits cancer cell growth, especially in the HepG2 cell line. • The inhibitory effect of LRD-22 is due to induction of apoptosis and cell cycle arrest. • LRD-22 inhibits Aurora-A phosphorylation which results in subsequent impairment of the p53 pathway. • LRD-22 suppresses tumor growth in xenograft mice without body weight loss.

  9. A novel DNA intercalator, butylamino-pyrimido[4',5':4,5]selenolo(2,3-b)quinoline, induces cell cycle arrest and apoptosis in leukemic cells.

    Science.gov (United States)

    Shahabuddin, M S; Nambiar, Mridula; Choudhary, Bibha; Advirao, Gopal M; Raghavan, Sathees C

    2010-02-01

    DNA intercalators are one of the most commonly used chemotherapeutic agents. Novel intercalating compounds of pyrimido[4',5':4,5]selenolo(2,3-b)quinoline series having a butylamino or piperazino group at fourth position (BPSQ and PPSQ, respectively) are studied. Our results showed that BPSQ induced cytotoxicity whereas PPSQ was cytostatic. The cytotoxicity induced by BPSQ was concentration- and time-dependent. Cell cycle analysis and tritiated thymidine assay revealed that BPSQ affects the cell cycle progression by arresting at S phase. The absence of p-histone H3 and reduction in the levels of PCNA in the cells treated with BPSQ further confirmed the cell cycle arrest. Further, annexin V staining, DNA fragmentation, nuclear condensation and changes in the expression levels of BCL2/BAD confirmed the activation of apoptosis. Activation of caspase 8 and lack of cleavage of caspase 9, caspase 3 and PARP suggest the possibility of BPSQ triggering extrinsic pathway for induction of apoptosis, which is discussed. Hence, we have identified a novel compound which would have clinical relevance in cancer chemotherapeutics. PMID:19142583

  10. Artesunate induces G0/G1 cell cycle arrest and iron-mediated mitochondrial apoptosis in A431 human epidermoid carcinoma cells.

    Science.gov (United States)

    Jiang, Zhongyong; Chai, Jin; Chuang, Henry Hon Fung; Li, Shifeng; Wang, Tianran; Cheng, Yi; Chen, Wensheng; Zhou, Deshan

    2012-07-01

    The anticancer effects of artesunate (ART) have been well documented. However, its potential against skin cancer has not been explored yet. Herein we reported that 60 μmol/l ART effectively inhibited A431 (human epidermoid carcinoma cells) growth but not that of HaCaT (normal human keratinocyte cells). Our results revealed that ART induced cell cycle arrest at G0/G1 phase through the downregulation of cyclin A1, cyclin B, cyclin D1, Cdk2, Cdk4, and Cdk6. This correlated with the upregulation of p21 and p27. The 5-bromodeoxyuridine incorporation assay also indicated that ART treatment reduced DNA synthesis in a time-dependent manner. Furthermore, ART induced mitochondrial apoptosis, as evidenced by annexin V/propidium iodide staining and western blot analysis. Interestingly, ART-induced apoptosis diminished under iron-deficient conditions but intensified under iron-overload conditions. Taken together, these findings demonstrated the potential of ART in treating skin cancer through the induction of G0/G1 cell cycle arrest and iron-mediated mitochondrial apoptosis and supported further investigations in other test systems. PMID:22421370

  11. Maternal influences on daughters' restrained eating behavior.

    Science.gov (United States)

    Francis, Lori A; Birch, Leann L

    2005-11-01

    This study examined whether mothers' preoccupation with their own weight and eating was linked to daughters' restrained eating behavior. Participants included 173 non-Hispanic, White mother-daughter dyads, measured longitudinally when daughters were ages 5, 7, 9, and 11. Mothers who were preoccupied with their own weight and eating reported higher levels of restricting daughters' intake and encouraging daughters to lose weight over time. Mothers' encouragement of daughters' weight loss was linked to daughters' restrained eating behavior; this relationship was partially mediated by daughters' perception of maternal pressure to lose weight. These findings suggest that mothers' preoccupation with weight and eating, via attempts to influence daughters' weight and eating, may place daughters at risk for developing problematic eating behaviors. PMID:16287400

  12. Higher order nuclear organization in growth arrest of humanmammary epithelial cells: A novel role for telomere-associated proteinTIN2

    Energy Technology Data Exchange (ETDEWEB)

    Kaminker, Patrick; Plachot, Cedric; Kim, Sahn-Ho; Chung, Peter; Crippen, Danielle; Petersen, Ole W.; Bissell, Mina J.; Campisi, Judith; Lelievre, Sophie A.

    2004-12-15

    Nuclear organization, such as the formation of specific nuclear subdomains, is generally thought to be involved in the control of cellular phenotype; however, there are relatively few specific examples of how mammalian nuclei organize during radical changes in phenotype, such as those which occur during differentiation and growth arrest. Using human mammary epithelial cells (HMECs) in which growth arrest is essential for morphological differentiation, we show that the arrest of cell proliferation is accompanied by a reorganization of the telomere-associated protein, TIN2, into one to three large nuclear subdomains. The large TIN2 domains do not contain telomeres and occur concomitant with the continued presence of TIN2 at telomeres. The TIN2 domains were sensitive to DNAse, but not RNAse, occurred frequently, but not exclusively near nucleoli, and overlapped often with dense domains containing heterochromatin protein l{gamma}. Expression of truncated forms of TIN2 simultaneously prevented the formation of TIN2 domains and relaxed the stringent morphogenesis-induced growth arrest in HMECs. Our findings reveal a novel extra-telomeric organization of TIN2 associated with the control of cell proliferation and identify TIN2 as an important regulator of mammary epithelial differentiation.

  13. CSBF/C10orf99, a novel potential cytokine, inhibits colon cancer cell growth through inducing G1 arrest.

    Science.gov (United States)

    Pan, Wen; Cheng, Yingying; Zhang, Heyu; Liu, Baocai; Mo, Xiaoning; Li, Ting; Li, Lin; Cheng, Xiaojing; Zhang, Lianhai; Ji, Jiafu; Wang, Pingzhang; Han, Wenling

    2014-01-01

    Cytokines are soluble proteins that exert their functions by binding specific receptors. Many cytokines play essential roles in carcinogenesis and have been developed for the treatment of cancer. In this study, we identified a novel potential cytokine using immunogenomics designated colon-derived SUSD2 binding factor (CSBF), also known as chromosome 10 open reading frame 99 (C10orf99). CSBF/C10orf99 is a classical secreted protein with predicted molecular mass of 6.5 kDa, and a functional ligand of Sushi Domain Containing 2 (SUSD2). CSBF/C10orf99 has the highest expression level in colon tissue. Both CSBF/C10orf99 and SUSD2 are down-regulated in colon cancer tissues and cell lines with different regulation mechanisms. CSBF/C10orf99 interacts with SUSD2 to inhibit colon cancer cell growth and induce G1 cell cycle arrest by down-regulating cyclin D and cyclin-dependent kinase 6 (CDK6). CSBF/C10orf99 displays a bell-shaped activity curve with the optimal effect at ~10 ng/ml. Its growth inhibitory effects can be blocked by sSUSD2-Fc soluble protein. Our results suggest that CSBF/C10orf99 is a novel potential cytokine with tumor suppressor functions. PMID:25351403

  14. Resibufogenin Induces G1-Phase Arrest through the Proteasomal Degradation of Cyclin D1 in Human Malignant Tumor Cells.

    Directory of Open Access Journals (Sweden)

    Masami Ichikawa

    Full Text Available Huachansu, a traditional Chinese medicine prepared from the dried toad skin, has been used in clinical studies for various cancers in China. Resibufogenin is a component of huachansu and classified as bufadienolides. Resibufogenin has been shown to exhibit the anti-proliferative effect against cancer cells. However, the molecular mechanism of resibufogenin remains unknown. Here we report that resibufogenin induces G1-phase arrest with hypophosphorylation of retinoblastoma (RB protein and down-regulation of cyclin D1 expression in human colon cancer HT-29 cells. Since the down-regulation of cyclin D1 was completely blocked by a proteasome inhibitor MG132, the suppression of cyclin D1 expression by resibufogenin was considered to be in a proteasome-dependent manner. It is known that glycogen synthase kinase-3β (GSK-3β induces the proteasomal degradation of cyclin D1. The addition of GSK-3β inhibitor SB216763 inhibited the reduction of cyclin D1 caused by resibufogenin. These effects on cyclin D1 by resibufogenin were also observed in human lung cancer A549 cells. These findings suggest that the anti-proliferative effect of resibufogenin may be attributed to the degradation of cyclin D1 caused by the activation of GSK-3β.

  15. Distinct Initiation and Maintenance Mechanisms Cooperate to Induce G1 Cell Cycle Arrest in Response to DNA Damage

    NARCIS (Netherlands)

    Agami, R.; Bernards, R.A.

    2000-01-01

    DNA damage causes stabilization of p53, leading to G1 arrest through induction of p21cip1. As this process requires transcription, several hours are needed to exert this response. We show that DNA damage causes an immediate and p53-independent G1 arrest, caused by rapid proteolysis of cyclin D1. Deg

  16. Overexpression of cell cycle regulator CDCA3 promotes oral cancer progression by enhancing cell proliferation with prevention of G1 phase arrest

    International Nuclear Information System (INIS)

    Cell division cycle associated 3 (CDCA3), part of the Skp1-cullin-F-box (SCF) ubiquitin ligase, refers to a trigger of mitotic entry and mediates destruction of the mitosis inhibitory kinase. Little is known about the relevance of CDCA3 to human malignancy including oral squamous cell carcinoma (OSCC). We aimed to characterize the expression state and function of CDCA3 in OSCC. We evaluated CDCA3 mRNA and protein expression in both OSCC-derived cell lines and primary OSCCs and performed functional analyses of CDCA3 in OSCC-derived cells using the shRNA system. The CDCA3 expression at both the mRNA and protein levels was frequently up-regulated in all cell lines examined and primary tumors (mRNA, 51/69, 74 %; protein, 79/95, 83 %) compared to normal controls (p < 0.001). In contrast, no significant level of CDCA3 protein expression was seen in oral premalignant lesions (OPLs) (n = 20) compared with the expression in OSCCs. Among the clinical variables analyzed, the CDCA3 expression status was closely related to tumor size (p < 0.05). In addition, suppression of CDCA3 expression with shRNA significantly (p < 0.05) inhibited cellular proliferation compared with the control cells by arresting cell-cycle progression at the G1 phase. Further, there was up-regulation of the cyclin-dependent kinase inhibitors (p21Cip1, p27Kip1, p15INK4B, and p16INK4A) in the knockdown cells. The current results showed that overexpression of CDCA3 occurs frequently during oral carcinogenesis and this overexpression might be associated closely with progression of OSCCs by preventing the arrest of cell-cycle progression at the G1 phase via decreased expression of the cyclin-dependent kinase inhibitors

  17. Dosimetry, measurement and properties of radon daughters and thoron daughters

    International Nuclear Information System (INIS)

    Various properties of radon and thoron daughter products are examined. Dosimeter methods and instrumentation (TLD and personal alpha dosimeters) are investigated as to performance under varying conditions such as humidity and pure or mixed atmospheric conditions. Optimized counting schemes are determined for the daughters of radon and thoron. An optimized counting scheme was experimentally examined under mine conditions. The optimization procedure takes into account the uncertainties associated with concentration, flow rate and radioactive decay. Measurements were made in two uranium mines at Elliot Lake, Ontario of the charged and unattached fractions of radon daughters in the mines. The physicochemical state of 218Po in air was determined by measurement of rate of neutralization, diffusion coefficient and fraction born charge. Careful control of experimental conditions made it possible to obtain more precise and detailed quantitative data than previously possible

  18. p-Cresol affects reactive oxygen species generation, cell cycle arrest, cytotoxicity and inflammation/atherosclerosis-related modulators production in endothelial cells and mononuclear cells.

    Directory of Open Access Journals (Sweden)

    Mei-Chi Chang

    Full Text Available AIMS: Cresols are present in antiseptics, coal tar, some resins, pesticides, and industrial solvents. Cresol intoxication leads to hepatic injury due to coagulopathy as well as disturbance of hepatic circulation in fatal cases. Patients with uremia suffer from cardiovascular complications, such as atherosclerosis, thrombosis, hemolysis, and bleeding, which may be partly due to p-cresol toxicity and its effects on vascular endothelial and mononuclear cells. Given the role of reactive oxygen species (ROS and inflammation in vascular thrombosis, the objective of this study was to evaluate the effect of p-cresol on endothelial and mononuclear cells. METHODS: EA.hy926 (EAHY endothelial cells and U937 cells were exposed to different concentrations of p-cresol. Cytotoxicity was evaluated by 3-(4,5-Dimethylthiazol-2-yl-2,5 -diphenyltetrazolium bromide (MTT assay and trypan blue dye exclusion technique, respectively. Cell cycle distribution was analyzed by propidium iodide flow cytometry. Endothelial cell migration was studied by wound closure assay. ROS level was measured by 2',7'-dichlorofluorescein diacetate (DCF fluorescence flow cytometry. Prostaglandin F2α (PGF2α, plasminogen activator inhibitor-1 (PAI-1, soluble urokinase plasminogen activator receptor (suPAR, and uPA production were determined by Enzyme-linked immunosorbant assay (ELISA. RESULTS: Exposure to 100-500 µM p-cresol decreased EAHY cell number by 30-61%. P-cresol also decreased the viability of U937 mononuclear cells. The inhibition of EAHY and U937 cell growth by p-cresol was related to induction of S-phase cell cycle arrest. Closure of endothelial wounds was inhibited by p-cresol (>100 µM. P-cresol (>50 µM also stimulated ROS production in U937 cells and EAHY cells but to a lesser extent. Moreover, p-cresol markedly stimulated PAI-1 and suPAR, but not PGF2α, and uPA production in EAHY cells. CONCLUSIONS: p-Cresol may contribute to atherosclerosis and thrombosis in patients with

  19. Oridonin nanosuspension was more effective than free oridonin on G2/M cell cycle arrest and apoptosis in the human pancreatic cancer PANC-1 cell line

    Directory of Open Access Journals (Sweden)

    Qi XL

    2012-04-01

    Full Text Available Xiaoli Qi1, Dianrui Zhang2, Xia Xu1, Feifei Feng2, Guijie Ren1, Qianqian Chu1, Qiang Zhang3, Keli Tian11Department of Biochemistry and Molecular Biology, Shandong University School of Medicine, Jinan, 2Department of Pharmaceutics, College of Pharmacy, Shandong University, Jinan, 3State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing, People's Republic of ChinaAbstract: Oridonin, a diterpenoid isolated from Rabdosia rubescencs, has been reported to have antitumor effects. However, low solubility has limited its clinical applications. Preparation of drugs in the form of nanosuspensions is an extensively utilized protocol. In this study, we investigated the anticancer activity of oridonin and oridonin nanosuspension on human pancreatic carcinoma PANC-1 cells. 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide assay was performed to investigate the effect of oridonin on cell growth. Propidium iodide and Hoechst 33342 staining were used to detect morphologic changes. The percentage of apoptosis and cell cycle progression was determined by flow cytometric method staining with propidium iodide. Annexin V-fluorescein isothiocyanate (FITC/PI staining was used to evaluate cell apoptosis by flow cytometry. Caspase-3 activity was measured by spectrophotometry. The apoptotic and cell cycle protein expression were determined by Western blot analysis. Both oridonin and oridonin nanosuspension induced apoptosis and G2/M phase cell cycle arrest, and the latter had a more significant cytotoxic effect. The ratio of Bcl-2/Bax protein expression was decreased and caspase-3 activity was stimulated. The expression of cyclin B1 and p-cdc2 (T161 was suppressed. Our results showed that oridonin nanosuspension was more effective than free oridonin on G2/M cell cycle arrest and apoptosis in the human pancreatic cancer PANC-1 cell line.Keywords: cyclin B1, cdc2, caspase-3, Bcl-2, Bax

  20. Α-MMC and MAP30, two ribosome-inactivating proteins extracted from Momordica charantia, induce cell cycle arrest and apoptosis in A549 human lung carcinoma cells.

    Science.gov (United States)

    Fan, Xiang; He, Lingli; Meng, Yao; Li, Gangrui; Li, Linli; Meng, Yanfa

    2015-05-01

    α‑Momorcharin (α‑MMC) and momordica anti‑human immunodeficiency virus protein (MAP30), produced by Momordica charantia, are ribosome‑inactivating proteins, which have been reported to exert inhibitory effects on cultured tumor cells. In order to further elucidate the functions of these agents, the present study aimed to investigate the effects of α‑MMC and MAP30 on cell viability, the induction of apoptosis, cell cycle arrest, DNA integrity and superoxide dismutase (SOD) activity. α‑MMC and MAP30 were purified from bitter melon seeds using ammonium sulfate precipitation in combination with sulfopropyl (SP)‑sepharose fast flow, sephacryl S‑100 and macro‑Cap‑SP chromatography. MTT, flow cytometric and DNA fragmentation analyses were then used to determine the effects of α‑MMC and MAP30 on human lung adenocarcinoma epithelial A549 cells. The results revealed that A549 cells were sensitive to α‑MMC and MAP30 cytotoxicity assays in vitro. Cell proliferation was significantly suppressed following α‑MMC and MAP30 treatment in a dose‑ and time‑dependent manner; in addition, the results indicated that MAP30 had a more potent anti‑tumor activity compared with that of α‑MMC. Cell cycle arrest in S phase and a significantly increased apoptotic rate were observed following treatment with α‑MMC and MAP30. Furthermore, DNA integrity analysis revealed that the DNA of A549 cells was degraded following treatment with α‑MMC and MAP30 for 48 h. The pyrogallol autoxidation method and nitrotetrazolium blue chloride staining were used to determine SOD activity, the results of which indicated that α‑MMC and MAP30 did not possess SOD activity. In conclusion, the results of the present study indicated that α‑MMC and MAP30 may have potential as novel therapeutic agents for the prophylaxis and treatment of cancer. PMID:25573293

  1. Sorafenib induces growth arrest and apoptosis of human glioblastoma cells via dephosphorylation of STAT3

    OpenAIRE

    Yang, Fan; Brown, Christine; Buettner, Ralf; HEDVAT, MICHAEL; Starr, Renate; Scuto, Anna; Schroeder, Anne; Jensen, Michael; Jove, Richard

    2010-01-01

    Glioblastoma is the most common type of primary brain tumor and is rapidly progressive with few treatment options. Here, we report that sorafenib (≤ 10 μM) inhibited cell proliferation and induced apoptosis in two established cell lines (U87, U251) and two primary cultures (PBT015, PBT022) from human glioblastomas. Effects of sorafenib on these tumor cells were associated with inhibiting phosphorylated STAT3 (Tyr705). Expression of a constitutively activated STAT3 mutant partially blocked the...

  2. Arrest of Myelination and Reduced Axon Growth when Schwann Cells Lack mTOR

    OpenAIRE

    Sherman, Diane L.; Krols, Michiel; Wu, Lai-Man N.; Grove, Matthew; Nave, Klaus-Armin; Gangloff, Yann-Gaël; Brophy, Peter J.

    2012-01-01

    In developing peripheral nerves differentiating Schwann cells sort individual axons from bundles and ensheath them to generate multiple layers of myelin. In recent years there has been an increasing understanding of the extracellular and intracellular factors that initiate and stimulate Schwann cell myelination together with a growing appreciation of some of the signalling pathways involved. However, our knowledge of how Schwann cell growth is regulated during myelination is still incomplete....

  3. β2-adrenoceptor blockage induces G1/S phase arrest and apoptosis in pancreatic cancer cells via Ras/Akt/NFκB pathway

    Directory of Open Access Journals (Sweden)

    Zhang Dong

    2011-11-01

    Full Text Available Abstract Background Smoking and stress, pancreatic cancer (PanCa risk factors, stimulate nitrosamine 4-(methylnitrosamino-1-(3-pyridyl-1-butanone (NNK and catecholamines production respectively. NNK and catecholamine bind the β-adrenoceptors and induce PanCa cell proliferation; and we have previously suggested that β-adrenergic antagonists may suppress proliferation and invasion and stimulate apoptosis in PanCa. To clarify the mechanism of apoptosis induced by β2-adrenergic antagonist, we hypothesize that blockage of the β2-adrenoceptor could induce G1/S phase arrest and apoptosis and Ras may be a key player in PanCa cells. Results The β1 and β2-adrenoceptor proteins were detected on the cell surface of PanCa cells from pancreatic carcinoma specimen samples by immunohistochemistry. The β2-adrenergic antagonist ICI118,551 significantly induced G1/S phase arrest and apoptosis compared with the β1-adrenergic antagonist metoprolol, which was determined by the flow cytometry assay. β2-adrenergic antagonist therapy significantly suppressed the expression of extracellular signal-regulated kinase, Akt, Bcl-2, cyclin D1, and cyclin E and induced the activation of caspase-3, caspase-9 and Bax by Western blotting. Additionally, the β2-adrenergic antagonist reduced the activation of NFκB in vitro cultured PanCa cells. Conclusions The blockage of β2-adrenoceptor markedly induced PanCa cells to arrest at G1/S phase and consequently resulted in cell death, which is possibly due to that the blockage of β2-adrenoceptor inhibited NFκB, extracellular signal-regulated kinase, and Akt pathways. Therefore, their upstream molecule Ras may be a key factor in the β2-adrenoceptor antagonist induced G1/S phase arrest and apoptosis in PanCa cells. The new pathway discovered in this study may provide an effective therapeutic strategy for PanCa.

  4. Control of daughter centriole formation by the pericentriolar material: Control of centriole duplication

    OpenAIRE

    Loncarek, Jadranka; Hergert, Polla; Magidson, Valentin; Khodjakov, Alexey

    2008-01-01

    Controlling the number of its centrioles is vital for the cell as supernumerary centrioles result in multipolar mitosis and genomic instability1,2. Normally, just one daughter centriole forms on each mature (mother) centriole3,4; however, a mother centriole can produce multiple daughters within a single cell cycle5,6. The mechanisms that prevent centriole ‘overduplication’ are poorly understood. Here we use laser microsurgery to test the hypothesis that attachment of the daughter centriole to...

  5. Synchronizing Progression of Schizosaccharomyces pombe Cells from Prophase through Mitosis and into S Phase with nda3-KM311 Arrest Release.

    Science.gov (United States)

    Hagan, Iain M; Grallert, Agnes; Simanis, Viesturs

    2016-01-01

    Here, we describe how the rapid reversibility of the nda3-KM311 cold-sensitive β-tubulin mutation was optimized by Mitsuhiro Yanagida's laboratory to synchronize mitotic progression in an entire cell population. The inability to form microtubules following the loss of β-tubulin function at 20°C triggers the spindle assembly checkpoint, which arrests mitotic progression. Restoration of β-tubulin function by rewarming to 30°C (or higher) releases the arrest, generating a highly synchronous progression through mitosis. The viability of nda3-KM311 strains at 30°C makes it feasible to generate double mutants between nda3-KM311 and any temperature-sensitive mutant that can also grow at 30°C. These double mutants can be used in reciprocal shift analyses, in which cold-induced early mitotic arrest is relieved by a shift to 36°C, which then inactivates the product of the second mutant gene. The addition of microtubule depolymerizing drugs before the return to 36°C will maintain checkpoint signaling at 36°C transiently, permitting analysis of the impact of temperature-sensitive mutations on checkpoint function. Silencing the checkpoint of nda3-KM311-arrested cells at 20°C through chemical inhibition of aurora kinase is a powerful way to study checkpoint recovery pathways and mitotic exit without anaphase. PMID:27480719

  6. Peptide nucleic acids arrest the growth of gastric cancer cells SGC7901

    Institute of Scientific and Technical Information of China (English)

    王宽; 张岂凡; 王锡山; 薛英威; 庞达; 傅松滨

    2004-01-01

    Background Peptide nucleic acid (PNA) has many characteristics useful in molecular biology. This paper described an effective way to raise the cell ingestion rate of PNA so as to kill gastric cancer cells.Methods Heteroduplexes of PNAs and oligonucleotides, wrapped by Lipofectamine 2000, were used to infect SGC7901 cells. The inhibitive effect of heteroduplexes was evaluated by analyzing cell clone forming and cell growth rate. Telomerase activity of SGC7901 cells was detected by polymerase chain reaction enzyme-linked immunosorbent assay (PCR-ELISA) and silver staining assay.Results PNAs showed a dose-dependent inhibition of cell proliferation. The percentage of proliferation inhibition was 99.4% after 7 days; the rate of cloning inhibition was 98.2% after 8 days;whereas for oligonucleotide groups, at the same concentration, the percentages were 50. 1% and 67. 5% respectively. Antisense PNA-DNA-Lipofectamine 2000 group (AP-D-L group) exhibited significantly different percentages from the control groups (P<0.05). The test result indicated that telomerase activity of the AP-D-L group was inhibited (P<0.05). At the same time, the impact on cell morphology was observed.Conclusions The results showed that PNAs are potent antisense reagents. The telomeraseassociated therapies are very promising for the treatment of malignant tumours.

  7. Kefir induces cell-cycle arrest and apoptosis in HTLV-1-negative malignant T-lymphocytes

    Directory of Open Access Journals (Sweden)

    Katia Maalouf

    2011-02-01

    Full Text Available Katia Maalouf1, Elias Baydoun2, Sandra Rizk11Department of Natural Sciences, Lebanese American University, Beirut, Lebanon; 2Department of Biology, American University of Beirut, Beirut, LebanonBackground: Adult lymphoblastic leukemia (ALL is a malignancy that occurs in white blood cells. The overall cure rate in children is 85%, whereas it is only 40% in adults. Kefir is an important probiotic that contains many bioactive ingredients, which give it unique health benefits. It has been shown to control several cellular types of cancer.Purpose: The present study investigates the effect of a cell-free fraction of kefir on CEM and Jurkat cells, which are human T-lymphotropic virus type I (HTLV-1-negative malignant T-lymphocytes.Methods: Cells were incubated with different kefir concentrations. The cytotoxicity of the compound was evaluated by determining the percentage viability of cells. The effect of all the noncytotoxic concentrations of kefir on the proliferation of CEM and Jurkat cells was then assessed. The levels of transforming growth factor-alpha (TGF-α, transforming growth factor- beta1 (TGF-β1, matrix metalloproteinase-2 (MMP-2, and MMP-9 mRNA upon kefir treatment were then analyzed using reverse transcriptase polymerase chain reaction (RT-PCR. Finally, the growth inhibitory effects of kefir on cell-cycle progression/apoptosis were assessed by Cell Death Detection (ELISA and flow cytometry.Results: The maximum cytotoxicity recorded after 48-hours treatment with 80 µg/µL kefir was only 42% and 39% in CEM and Jurkat cells, respectively. The percent reduction in proliferation was very significant, and was dose-, and time-dependent. In both cell lines, kefir exhibited its antiproliferative effect by downregulating TGF-α and upregulating TGF- β1 mRNA expression. Upon kefir treatment, a marked increase in cell-cycle distribution was noted in the preG1 phase of CEM and Jurkat cells, indicating the proapoptotic effect of kefir, which was

  8. Kefir induces cell-cycle arrest and apoptosis in HTLV-1-negative malignant T-lymphocytes

    International Nuclear Information System (INIS)

    Adult lymphoblastic leukemia (ALL) is a malignancy that occurs in white blood cells. The overall cure rate in children is 85%, whereas it is only 40% in adults. Kefir is an important probiotic that contains many bioactive ingredients, which give it unique health benefits. It has been shown to control several cellular types of cancer. The present study investigates the effect of a cell-free fraction of kefir on CEM and Jurkat cells, which are human T-lymphotropic virus type I (HTLV-1)-negative malignant T-lymphocytes. Cells were incubated with different kefir concentrations. The cytotoxicity of the compound was evaluated by determining the percentage viability of cells. The effect of all the noncytotoxic concentrations of kefir on the proliferation of CEM and Jurkat cells was then assessed. The levels of transforming growth factor-alpha (TGF-α), transforming growth factor- beta1 (TGF-β1), matrix metalloproteinase-2 (MMP-2), and MMP-9 mRNA upon kefir treatment were then analyzed using reverse transcriptase polymerase chain reaction (RT-PCR). Finally, the growth inhibitory effects of kefir on cell-cycle progression/apoptosis were assessed by Cell Death Detection (ELISA) and flow cytometry. The maximum cytotoxicity recorded after 48-hours treatment with 80 μg/μL kefir was only 42% and 39% in CEM and Jurkat cells, respectively. The percent reduction in proliferation was very significant, and was dose-, and time-dependent. In both cell lines, kefir exhibited its antiproliferative effect by downregulating TGF-α and upregulating TGF-β1 mRNA expression. Upon kefir treatment, a marked increase in cell-cycle distribution was noted in the preG1 phase of CEM and Jurkat cells, indicating the proapoptotic effect of kefir, which was further confirmed by Cell Death Detection ELISA. However, kefir did not affect the mRNA expression of metalloproteinases needed for the invasion of leukemic cell lines. In conclusion, kefir is effective in inhibiting proliferation and inducing

  9. 17-Allylamino-17-demethoxygeldanamycin induces downregulation of critical Hsp90 protein clients and results in cell cycle arrest and apoptosis of human urinary bladder cancer cells

    International Nuclear Information System (INIS)

    17-Allylamino-17-demethoxygeldanamycin (17-AAG), a benzoquinone ansamycin antibiotic, specifically targets heat shock protein 90 (Hsp90) and interferes with its function as a molecular chaperone that maintains the structural and functional integrity of various protein clients involved in cellular signaling. In this study, we have investigated the effect of 17-AAG on the regulation of Hsp90-dependent signaling pathways directly implicated in cell cycle progression, survival and motility of human urinary bladder cancer cell lines. We have used MTT-based assays, FACS analysis, Western blotting, semi-quantitative RT-PCR, immunocytochemistry and scratch-wound assay in RT4, RT112 and T24 human urinary bladder cancer cell lines. We have demonstrated that, upon 17-AAG treatment, bladder cancer cells are arrested in the G1 phase of the cell cycle and eventually undergo apoptotic cell death in a dose-dependent manner. Furthermore, 17-AAG administration was shown to induce a pronounced downregulation of multiple Hsp90 protein clients and other downstream effectors, such as IGF-IR, Akt, IKK-α, IKK-β, FOXO1, ERK1/2 and c-Met, resulting in sequestration-mediated inactivation of NF-κB, reduced cell proliferation and decline of cell motility. In total, we have clearly evinced a dose-dependent and cell type-specific effect of 17-AAG on cell cycle progression, survival and motility of human bladder cancer cells, due to downregulation of multiple Hsp90 clients and subsequent disruption of signaling integrity

  10. Higher Initial DNA Damage and Persistent Cell Cycle Arrest after Carbon Ion Irradiation Compared to X-irradiation in Prostate and Colon Cancer Cells

    Science.gov (United States)

    Suetens, Annelies; Konings, Katrien; Moreels, Marjan; Quintens, Roel; Verslegers, Mieke; Soors, Els; Tabury, Kevin; Grégoire, Vincent; Baatout, Sarah

    2016-01-01

    The use of charged-particle beams, such as carbon ions, is becoming a more and more attractive treatment option for cancer therapy. Given the precise absorbed dose-localization and an increased biological effectiveness, this form of therapy is much more advantageous compared to conventional radiotherapy, and is currently being used for treatment of specific cancer types. The high ballistic accuracy of particle beams deposits the maximal dose to the tumor, while damage to the surrounding healthy tissue is limited. In order to better understand the underlying mechanisms responsible for the increased biological effectiveness, we investigated the DNA damage and repair kinetics and cell cycle progression in two p53 mutant cell lines, more specifically a prostate (PC3) and colon (Caco-2) cancer cell line, after exposure to different radiation qualities. Cells were irradiated with various absorbed doses (0, 0.5, and 2 Gy) of accelerated 13C-ions at the Grand Accélérateur National d’Ions Lourds facility (Caen, France) or with X-rays (0, 0.1, 0.5, 1, 2, and 5 Gy). Microscopic analysis of DNA double-strand breaks showed dose-dependent increases in γ-H2AX foci numbers and foci occupancy after exposure to both types of irradiation, in both cell lines. However, 24 h after exposure, residual damage was more pronounced after lower doses of carbon ion irradiation compared to X-irradiation. Flow cytometric analysis showed that carbon ion irradiation induced a permanent G2/M arrest in PC3 cells at lower doses (2 Gy) compared to X-rays (5 Gy), while in Caco-2 cells the G2/M arrest was transient after irradiation with X-rays (2 and 5 Gy) but persistent after exposure to carbon ions (2 Gy). PMID:27148479

  11. Zerumbone-loaded nanostructured lipid carrier induces G2/M cell cycle arrest and apoptosis via mitochondrial pathway in a human lymphoblastic leukemia cell line

    Directory of Open Access Journals (Sweden)

    Rahman HS

    2014-01-01

    Full Text Available Heshu Sulaiman Rahman,1–3 Abdullah Rasedee,1,2 Ahmad Bustamam Abdul,2,4 Nazariah Allaudin Zeenathul,1,2 Hemn Hassan Othman,1,3 Swee Keong Yeap,2 Chee Wun How,2 Wan Abd Ghani Wan Nor Hafiza4,51Faculty of Veterinary Medicine, 2Institute of Bioscience, Universiti Putra Malaysia, Selangor, Malaysia; 3Faculty of Veterinary Medicine, University of Sulaimanyah, Sulaimanyah City, Kurdistan Region, Northern Iraq; 4Faculty of Medicine and Health Science, Universiti Putra Malaysia, Selangor, Malaysia; 5College of Medical Laboratory Technology, Institute for Medical Research, Kuala Lumpur, MalaysiaAbstract: This investigation evaluated the antileukemia properties of a zerumbone (ZER-loaded nanostructured lipid carrier (NLC prepared by hot high-pressure homogenization techniques in an acute human lymphoblastic leukemia (Jurkat cell line in vitro. The apoptogenic effect of the ZER-NLC on Jurkat cells was determined by fluorescent and electron microscopy, Annexin V-fluorescein isothiocyanate, Tdt-mediated dUTP nick-end labeling assay, cell cycle analysis, and caspase activity. An MTT (3-(4,5-dimethylthiazol-2-yl-2,5 diphenyltetrazolium bromide assay showed that ZER-NLC did not have adverse effects on normal human peripheral blood mononuclear cells. ZER-NLC arrested the Jurkat cells at G2/M phase with inactivation of cyclin B1 protein. The study also showed that the antiproliferative effect of ZER-NLC on Jurkat cells is through the intrinsic apoptotic pathway via activation of caspase-3 and caspase-9, release of cytochrome c from the mitochondria into the cytosol, and subsequent cleavage of poly (adenosine diphosphate-ribose polymerase (PARP. These findings show that the ZER-NLC is a potentially useful treatment for acute lymphoblastic leukemia in humans.Keywords: zerumbone-loaded nanostructured lipid carrier, cell cycle arrest, apoptosis, mitochondrial pathway

  12. Evaluation and prediction of the HIV-1 central polypurine tract influence on foamy viral vectors to transduce dividing and growth-arrested cells.

    Science.gov (United States)

    Shityakov, Sergey; Förster, Carola; Rethwilm, Axel; Dandekar, Thomas

    2014-01-01

    Retroviral vectors are potent tools for gene delivery and various biomedical applications. To accomplish a gene transfer task successfully, retroviral vectors must effectively transduce diverse cell cultures at different phases of a cell cycle. However, very promising retroviral vectors based on the foamy viral (FV) backbone lack the capacity to efficiently transduce quiescent cells. It is hypothesized that this phenomenon might be explained as the inability of foamy viruses to form a pre-integration complex (PIC) with nuclear import activity in growth-arrested cells, which is the characteristic for lentiviruses (HIV-1). In this process, the HIV-1 central polypurine tract (cPPT) serves as a primer for plus-strand synthesis to produce a "flap" element and is believed to be crucial for the subsequent double-stranded cDNA formation of all retroviral RNA genomes. In this study, the effects of the lentiviral cPPT element on the FV transduction potential in dividing and growth-arrested (G1/S phase) adenocarcinomic human alveolar basal epithelial (A549) cells are investigated by experimental and theoretical methods. The results indicated that the HIV-1 cPPT element in a foamy viral vector background will lead to a significant reduction of the FV transduction and viral titre in growth-arrested cells due to the absence of PICs with nuclear import activity. PMID:25009830

  13. Human Herpesvirus-6 U14 Induces Cell-Cycle Arrest in G2/M Phase by Associating with a Cellular Protein, EDD.

    Directory of Open Access Journals (Sweden)

    Junko Mori

    Full Text Available The human herpesvirus-6 (HHV-6 infection induces cell-cycle arrest. In this study, we found that the HHV-6-encoded U14 protein induced cell-cycle arrest at G2/M phase via an association with the cellular protein EDD, a mediator of DNA-damage signal transduction. In the early phase of HHV-6 infection, U14 colocalized with EDD dots in the nucleus, and similar colocalization was also observed in cells transfected with a U14 expression vector. When the carboxyl-terminal region of U14 was deleted, no association of U14 and EDD was observed, and the percentage of cells in G2/M decreased relative to that in cells expressing wild-type U14, indicating that the C-terminal region of U14 and the U14-EDD association are critical for the cell-cycle arrest induced by U14. These results indicate that U14 is a G2/M checkpoint regulator encoded by HHV-6.

  14. A role for transcriptional repression of p21CIP1 by c-Myc in overcoming transforming growth factor β-induced cell-cycle arrest

    OpenAIRE

    Claassen, Gisela F.; Hann, Stephen R.

    2000-01-01

    c-Myc plays a vital role in cell-cycle progression. Deregulated expression of c-Myc can overcome cell-cycle arrest in order to promote cellular proliferation. Transforming growth factor β (TGFβ) treatment of immortalized human keratinocyte cells inhibits cell-cycle progression and is characterized by down-regulation of c-Myc followed by up-regulation of p21CIP1. A direct role of c-Myc in this pathway was demonstrated by the observation that ectopic expression of c-Myc overcame the cell-cycle ...

  15. Increased expression of cyclin B1 mRNA coincides with diminished G2-phase arrest in irradiated HeLa cells treated with staurosporine or caffeine

    International Nuclear Information System (INIS)

    The irradiation of cells results in delayed progression through the G2 phase of the cell cycle. Treatment of irradiated HeLa cells with caffeine greatly reduces the G2-phase delay, while caffeine does not alter progression of cells through the cell cycle in unirradiated cells. In this report we demonstrate that treatment of HeLa cells with the kinase inhibitor staurosporine, but not with the inhibitor H7, also results in a reduction of the G2-phase arrest after irradiation. Cell cycle progression in unirradiated cells is unaffected by 4.4 nM (2ng/ml) staurosporine, which releases the radiation-induced G2-phase arrest. In HeLa cells, the G2-phase delay after irradiation in S phase is accompanied by decreased expression of cyclin B1 mRNA. Coincident with the reduction in G2-phase delay, we observed an increase in cyclin B1 mRNA accumulation in irradiated, staurosporine-treated cells compared to cells treated with irradiation alone. Caffeine treatment of irradiated HeLa cells also resulted in an elevation in the levels of cyclin B1 message. These results support the hypothesis that diminished cyclin B1 mRNA levels influence G2-phase arrest to some degree. The findings that both staurosporine and caffeine treatments reverse the depression in cyclin B1 expression suggest that these two compounds may act on a common pathway of cell cycle control in response to radiation injury. 33 refs., 6 figs

  16. Growth arrest and apoptosis of human hepatocellular carcinoma cells induced by hexamethylene bisacetamide

    OpenAIRE

    Ouyang, Gao-Liang; Cai, Qiu-Feng; Min LIU; Chen, Rui-Chuan; Huang, Zhi; Jiang, Rui-Sheng; Chen, Fu; Hong, Shui-Gen; Bao, Shi-Deng

    2004-01-01

    AIM: To investigate the cellular effects of hybrid polar compound hexamethylene bisacetamide (HMBA) on the growth and apoptosis of human hepatocellular carcinoma cells and to provide the molecular mechanism for potential application of HMBA in the treatment of liver cancer.

  17. Antisense oligonucleotide targeting at the initiator of hTERT arrests growth of hepatoma cells

    Institute of Scientific and Technical Information of China (English)

    Su-Xia Liu; Wen-Sheng Sun; Ying-Lin Cao; Chun-Hong Ma; Li-Hui Han; Li-Ning Zhang; Zhen-Guang Wang; Fa-Liang Zhu

    2004-01-01

    AIM: To evaluate the inhibitory effect of antisense phosphorothioate oligonucleotide (asON) complementary to the initiator of human telomerase catalytic subunit (hTERT)on the growth of hepatoma cells.METHODS: The as-hTERT was synthesized by using a DNA synthesizer. HepG2.2.15 cells were treated with ashTERT at the concentration of 10 μmol/L. After 72 h, these cells were obtained for detecting growth inhibition,telomerase activity using the methods of MTT, TRAP-PCR-ELISA, respectively. BALB/c(nu/nu) mice were injected HepG2.2.15 cells and a human-nude mice model was obtained. There were three groups for anti-tumor activity study. Once tumors were established, these animals in the first group were administered as-hTERT and saline.Apoptosis of tumor cells was detected by FCM. In the 2nd group, the animals were injected HepG2.2.15 cells together with as-hTERT. In the third group, the animals were given as-hTERT 24 hours postinjection of HepG2.2.15 cells. The anti-HBV effects were assayed with ELISA ih vitro and in vivo.RESULTS: Growth inhibition was observed in cells treated with as-hTERT ih vitro. A significant different in the value of A570-A630 was found between cells treated with as-hTERT and control (P<0.01) by MTT method. The telomerase activity of tumor cells treated with as-hTERT was reduced,the value of A450 nm was 0.42 compared to control (1,49)with TRAP-PCR-ELISA. The peak of apoptosis in tumor cells given as-hTERT was 21. 12%, but not seen in saline-treated control. A prolonged period of carcinogenesis was observed in the second and third group animals. There was inhibitory effect on the expression of HBsAg and HBeAg ih vivo and in vitro.CONCLUSION: As-hTERT has an anti-tumor activity, which may be useful for gene therapy of tumors.

  18. Epithelial Cell Proliferation Arrest Induced by Lactate and Acetate from Lactobacillus casei and Bifidobacterium breve

    OpenAIRE

    Matsuki, Takahiro; Pédron, Thierry; Regnault, Béatrice; Mulet, Céline; Hara, Taeko; Sansonetti, Philippe J.

    2013-01-01

    In an attempt to identify and characterize how symbiotic bacteria of the gut microbiota affect the molecular and cellular mechanisms of epithelial homeostasis, intestinal epithelial cells were co-cultured with either Lactobacillus or Bifidobacterium as bona fide symbionts to examine potential gene modulations. In addition to genes involved in the innate immune response, genes encoding check-point molecules controlling the cell cycle were among the most modulated in the course of these interac...

  19. Effect of caffeine on gamma-ray induced G2 arrest in well-synchronized Chinese hamster ovary cells in vitro

    International Nuclear Information System (INIS)

    G1-rich cells were separated from exponentially growing asynchronous cultured Chinese hamster ovary (CHO-K1) cells by centrifugal elutriation and a Coulter Counter. The G1-rich cells were incubated in medium that contained hydroxyurea (HU) to kill S phase cells and obtain the purest G1/S boundary cells possible. The HU-treated cells were washed, and were again incubated, in medium without HU, to allow these well-synchronized G1/S boundary cells to progress to S and G2/M phases. At various times after release from G1/S boundary, 4 Gy of gamma-ray and/or caffeine was administered to the cells. Eight hours after the removal of HU, cell-cycle analysis was performed with a flow cytometer. G2 arrest induced by gamma-rays was clearly shown when radiation was given earlier than 6.5 hours after HU removal. G2 arrest induced by radiation given 0.5-6.5 hours after HU removal was reduced by caffeine treatment given 6.0-6.5 hours after HU removal. Caffeine released radiation-induced G2 arrest when the radiation was given before the cultured cells entered G2/M phase and when caffeine was applied to the irradiated cells at the time when G1/S boundary cells not treated by radiation or with caffeine entered G2/M phase. Our method of centrifugal elutriation combined with incubation with HU was useful for isolating pure G1/S boundary cells from in vitro asynchronous cultures. (author)

  20. CRM1 inhibitor S109 suppresses cell proliferation and induces cell cycle arrest in renal cancer cells

    OpenAIRE

    Liu, Xuejiao; Chong, Yulong; Liu, Huize; Han, Yan; Niu, Mingshan

    2016-01-01

    Abnormal localization of tumor suppressor proteins is a common feature of renal cancer. Nuclear export of these tumor suppressor proteins is mediated by chromosome region maintenance-1 (CRM1). Here, we investigated the antitumor eff ects of a novel reversible inhibitor of CRM1 on renal cancer cells. We found that S109 inhibits the CRM1-mediated nuclear export of RanBP1 and reduces protein levels of CRM1. Furthermore, the inhibitory eff ect of S109 on CRM1 is reversible. Our data demonstrated ...

  1. Studies on the effect of cell cycle arrest on central metabolism in the diatom Phaeodactylum tricornutum, using physiological and systems biology approaches

    Science.gov (United States)

    Kim, Joomi

    Diatoms (Bacillarophyceae) are photosynthetic unicellular microalgae that have risen to ecological prominence in the modern oceans over the past 30 million years. They are excellent candidates for biodiesel feedstocks. Global climate change has led to an interest in algal triacylglycerols (TAGs) as feedstocks for sustainable biodiesel, and diatoms are attractive candidates for TAG production as one of the most productive and environmentally flexible algae in the contemporary oceans. For Chapter 2, a genome-scale metabolic model was constructed to calculate intracellular fluxes of a diatom under different growth conditions. The model identified enzymes that may be relevant to increasing lipid synthesis, explored how transporters affect flux outputs, and explored unusual features of diatoms, including the Entner-Douderoff and phosphoketolase pathways, and glycolytic enzymes in their mitochondria. Chapter 3 discusses how cell cycle arrest via cyclin-dependent kinase (Cdk) inhibition, can increase accumulation of TAGs, and shift metabolism away from protein synthesis. For Chapter 4, transcriptome analysis of cells under cell cycle arrest was performed to show that the pattern of gene expression was fundamentally different from nitrogen stress. Most of the genes related to fatty acid and TAG synthesis were up-regulated. The gene expression pattern for light harvesting complexes was similar to cells stressed by high light, suggesting that arrested cells have smaller sinks for photosynthetically generated electrons.

  2. Cell diameter measurements obtained with a handheld cell counter could be used as a surrogate marker of G2/M arrest and apoptosis in colon cancer cell lines exposed to SN-38

    Energy Technology Data Exchange (ETDEWEB)

    Tahara, Makiko [Oncogene Research Unit/Cancer Prevention Unit, Tochigi Cancer Center Research Institute, Utsunomiya, Tochigi (Japan); Department of Gastrointestinal Surgery, Jichi Medical University, Shimotsuke, Tochigi (Japan); Inoue, Takeshi [Oncogene Research Unit/Cancer Prevention Unit, Tochigi Cancer Center Research Institute, Utsunomiya, Tochigi (Japan); Miyakura, Yasuyuki; Horie, Hisanaga; Yasuda, Yoshikazu [Department of Gastrointestinal Surgery, Jichi Medical University, Shimotsuke, Tochigi (Japan); Fujii, Hirofumi [Division of Clinical Oncology, Jichi Medical University, Shimotsuke, Tochigi (Japan); Kotake, Kenjiro [Department of Surgery, Tochigi Cancer Center, Utsunomiya, Tochigi (Japan); Sugano, Kokichi, E-mail: ksugano@tcc.pref.tochigi.lg.jp [Oncogene Research Unit/Cancer Prevention Unit, Tochigi Cancer Center Research Institute, Utsunomiya, Tochigi (Japan)

    2013-05-17

    Highlights: •Chemo-sensitivity to SN-38 was assayed by the automated cell counter. •Colon cancer cell line, HCT116 cells were more sensitive to SN-38 than HT29 cells. •Increase of cell size reflects G2/M arrest. •Appearance of small particles indicates cell apoptosis. -- Abstract: In vitro assessment of chemosensitivity are important for experiments evaluating cancer therapies. The Scepter 2.0 cell counter, an automated handheld device based on the Coulter principle of impedance-based particle detection, enables the accurate discrimination of cell populations according to cell size and volume. In this study, the effects of SN-38, the active metabolite of irinotecan, on the colon cancer cell lines HCT116 and HT29 were evaluated using this device. The cell count data obtained with the Scepter counter were compared with those obtained with the {sup 3}H-thymidine uptake assay, which has been used to measure cell proliferation in many previous studies. In addition, we examined whether the changes in the size distributions of these cells reflected alterations in the frequency of cell cycle arrest and/or apoptosis induced by SN-38 treatment. In our experiments using the Scepter 2.0 cell counter, the cell counts were demonstrated to be accurate and reproducible measure and alterations of cell diameter reflected G2/M cell cycle arrest and apoptosis. Our data show that easy-to-use cell counting tools can be utilized to evaluate the cell-killing effects of novel treatments on cancer cells in vitro.

  3. Cell diameter measurements obtained with a handheld cell counter could be used as a surrogate marker of G2/M arrest and apoptosis in colon cancer cell lines exposed to SN-38

    International Nuclear Information System (INIS)

    Highlights: •Chemo-sensitivity to SN-38 was assayed by the automated cell counter. •Colon cancer cell line, HCT116 cells were more sensitive to SN-38 than HT29 cells. •Increase of cell size reflects G2/M arrest. •Appearance of small particles indicates cell apoptosis. -- Abstract: In vitro assessment of chemosensitivity are important for experiments evaluating cancer therapies. The Scepter 2.0 cell counter, an automated handheld device based on the Coulter principle of impedance-based particle detection, enables the accurate discrimination of cell populations according to cell size and volume. In this study, the effects of SN-38, the active metabolite of irinotecan, on the colon cancer cell lines HCT116 and HT29 were evaluated using this device. The cell count data obtained with the Scepter counter were compared with those obtained with the 3H-thymidine uptake assay, which has been used to measure cell proliferation in many previous studies. In addition, we examined whether the changes in the size distributions of these cells reflected alterations in the frequency of cell cycle arrest and/or apoptosis induced by SN-38 treatment. In our experiments using the Scepter 2.0 cell counter, the cell counts were demonstrated to be accurate and reproducible measure and alterations of cell diameter reflected G2/M cell cycle arrest and apoptosis. Our data show that easy-to-use cell counting tools can be utilized to evaluate the cell-killing effects of novel treatments on cancer cells in vitro

  4. Methamphetamine alters the normal progression by inducing cell cycle arrest in astrocytes.

    Directory of Open Access Journals (Sweden)

    Austin R Jackson

    Full Text Available Methamphetamine (MA is a potent psychostimulant with a high addictive capacity, which induces many deleterious effects on the brain. Chronic MA abuse leads to cognitive dysfunction and motor impairment. MA affects many cells in the brain, but the effects on astrocytes of repeated MA exposure is not well understood. In this report, we used Gene chip array to analyze the changes in the gene expression profile of primary human astrocytes treated with MA for 3 days. Range of genes were found to be differentially regulated, with a large number of genes significantly downregulated, including NEK2, TTK, TOP2A, and CCNE2. Gene ontology and pathway analysis showed a highly significant clustering of genes involved in cell cycle progression and DNA replication. Further pathway analysis showed that the genes downregulated by multiple MA treatment were critical for G2/M phase progression and G1/S transition. Cell cycle analysis of SVG astrocytes showed a significant reduction in the percentage of cell in the G2/M phase with a concomitant increase in G1 percentage. This was consistent with the gene array and validation data, which showed that repeated MA treatment downregulated the genes associated with cell cycle regulation. This is a novel finding, which explains the effect of MA treatment on astrocytes and has clear implication in neuroinflammation among the drug abusers.

  5. Conditional inactivation of PDCD2 induces p53 activation and cell cycle arrest

    Directory of Open Access Journals (Sweden)

    Celine J. Granier

    2014-08-01

    Full Text Available PDCD2 (programmed cell death domain 2 is a highly conserved, zinc finger MYND domain-containing protein essential for normal development in the fly, zebrafish and mouse. The molecular functions and cellular activities of PDCD2 remain unclear. In order to better understand the functions of PDCD2 in mammalian development, we have examined PDCD2 activity in mouse blastocyst embryos, as well as in mouse embryonic stem cells (ESCs and embryonic fibroblasts (MEFs. We have studied mice bearing a targeted PDCD2 locus functioning as a null allele through a splicing gene trap, or as a conditional knockout, by deletion of exon2 containing the MYND domain. Tamoxifen-induced knockout of PDCD2 in MEFs, as well as in ESCs, leads to defects in progression from the G1 to the S phase of cell cycle, associated with increased levels of p53 protein and p53 target genes. G1 prolongation in ESCs was not associated with induction of differentiation. Loss of entry into S phase of the cell cycle and marked induction of nuclear p53 were also observed in PDCD2 knockout blastocysts. These results demonstrate a unique role for PDCD2 in regulating the cell cycle and p53 activation during early embryonic development of the mouse.

  6. Resveratrol analogue 3,4,4′,5-tetramethoxystilbene inhibits growth, arrests cell cycle and induces apoptosis in ovarian SKOV‐3 and A-2780 cancer cells

    International Nuclear Information System (INIS)

    In the screening studies, cytotoxicity of 12 methylated resveratrol analogues on 11 human cancer cell lines was examined. The most active compound 3,4,4′5-tetramethoxystilbene (DMU-212) and two ovarian cancer cell lines A-2780 (IC50 = 0.71 μM) and SKOV-3 (IC50 = 11.51 μM) were selected for further investigation. To determine the mechanism of DMU-212 cytotoxicity, its ability to induce apoptosis was examined. DMU-212 arrested cell cycle in the G2/M or G0/G1 phase which resulted in apoptosis of both cell lines. The expression level of 84 apoptosis-related genes was investigated. In SKOV-3 cells DMU-212 caused up-regulation of pro-apoptotic Bax, Apaf-1 and p53 genes, specific to intrinsic pathway of apoptosis, and a decrease in Bcl-2 and Bcl 2110 mRNA expressions. Conversely, in A-2780 cells an increased expression of pro-apoptotic genes Fas, FasL, TNF, TNFRSF10A, TNFRSF21, TNFRSF16 specific to extracellular mechanism of apoptosis was observed. There are no data published so far regarding the receptor mediated apoptosis induced by DMU-212. The activation of caspase-3/7 was correlated with decreased TRAF-1 and BIRC-2 expression level in A-2780 cells exposed to DMU-212. DMU-212 caused a decrease in CYP1A1 and CYP1B1 mRNA levels in A-2780 by 50% and 75%, and in SKOV-3 cells by 15% and 45%, respectively. The protein expression was also reduced in both cell lines. It is noteworthy that the expression of CYP1B1 protein was entirely inhibited in A-2780 cells treated with DMU-212. It can be suggested that different CYP1B1 expression patterns in either ovarian cell line may affect their sensitivity to cytotoxic activity of DMU-212. -- Highlights: ► DMU-212 was the most cytotoxic among 12 O-methylated resveratrol analogues. ► DMU-212 arrested cell cycle at G2/M and G0/G1phase ► DMU-212 triggered mitochondria- and receptor‐mediated apoptosis. ► DMU-212 entirely inhibited CYP1B1 protein expression in A-2780 cells.

  7. Resveratrol analogue 3,4,4′,5-tetramethoxystilbene inhibits growth, arrests cell cycle and induces apoptosis in ovarian SKOV‐3 and A-2780 cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Piotrowska, Hanna; Myszkowski, Krzysztof; Ziółkowska, Alicja [Department of Toxicology, Poznan University of Medical Sciences, Poznan (Poland); Kulcenty, Katarzyna [Chair of Medical Biotechnology, Poznan University of Medical Sciences, Poznan (Poland); Wierzchowski, Marcin [Department of Chemical Technology of Drugs, Poznan University of Medical Sciences, Poznan (Poland); Kaczmarek, Mariusz [Department of Clinical Immunology, Poznan University of Medical Sciences, Poznan (Poland); Murias, Marek [Department of Toxicology, Poznan University of Medical Sciences, Poznan (Poland); Kwiatkowska-Borowczyk, Eliza [Chair of Medical Biotechnology, Poznan University of Medical Sciences, Poznan (Poland); Department of Cancer Diagnostics and Immunology, Greater Poland Cancer Centre, Poznan (Poland); Jodynis-Liebert, Jadwiga, E-mail: liebert@ump.edu.pl [Department of Toxicology, Poznan University of Medical Sciences, Poznan (Poland)

    2012-08-15

    In the screening studies, cytotoxicity of 12 methylated resveratrol analogues on 11 human cancer cell lines was examined. The most active compound 3,4,4′5-tetramethoxystilbene (DMU-212) and two ovarian cancer cell lines A-2780 (IC{sub 50} = 0.71 μM) and SKOV-3 (IC{sub 50} = 11.51 μM) were selected for further investigation. To determine the mechanism of DMU-212 cytotoxicity, its ability to induce apoptosis was examined. DMU-212 arrested cell cycle in the G2/M or G0/G1 phase which resulted in apoptosis of both cell lines. The expression level of 84 apoptosis-related genes was investigated. In SKOV-3 cells DMU-212 caused up-regulation of pro-apoptotic Bax, Apaf-1 and p53 genes, specific to intrinsic pathway of apoptosis, and a decrease in Bcl-2 and Bcl 2110 mRNA expressions. Conversely, in A-2780 cells an increased expression of pro-apoptotic genes Fas, FasL, TNF, TNFRSF10A, TNFRSF21, TNFRSF16 specific to extracellular mechanism of apoptosis was observed. There are no data published so far regarding the receptor mediated apoptosis induced by DMU-212. The activation of caspase-3/7 was correlated with decreased TRAF-1 and BIRC-2 expression level in A-2780 cells exposed to DMU-212. DMU-212 caused a decrease in CYP1A1 and CYP1B1 mRNA levels in A-2780 by 50% and 75%, and in SKOV-3 cells by 15% and 45%, respectively. The protein expression was also reduced in both cell lines. It is noteworthy that the expression of CYP1B1 protein was entirely inhibited in A-2780 cells treated with DMU-212. It can be suggested that different CYP1B1 expression patterns in either ovarian cell line may affect their sensitivity to cytotoxic activity of DMU-212. -- Highlights: ► DMU-212 was the most cytotoxic among 12 O-methylated resveratrol analogues. ► DMU-212 arrested cell cycle at G2/M and G0/G1phase ► DMU-212 triggered mitochondria- and receptor‐mediated apoptosis. ► DMU-212 entirely inhibited CYP1B1 protein expression in A-2780 cells.

  8. Inhibition of mTORC2 Induces Cell-Cycle Arrest and Enhances the Cytotoxicity of Doxorubicin by Suppressing MDR1 Expression in HCC Cells.

    Science.gov (United States)

    Chen, Bryan Wei; Chen, Wei; Liang, Hui; Liu, Hao; Liang, Chao; Zhi, Xiao; Hu, Li-Qiang; Yu, Xia-Zhen; Wei, Tao; Ma, Tao; Xue, Fei; Zheng, Lei; Zhao, Bin; Feng, Xin-Hua; Bai, Xue-Li; Liang, Ting-Bo

    2015-08-01

    mTOR is aberrantly activated in hepatocellular carcinoma (HCC) and plays pivotal roles in tumorigenesis and chemoresistance. Rapamycin has been reported to exert antitumor activity in HCC and sensitizes HCC cells to cytotoxic agents. However, due to feedback activation of AKT after mTOR complex 1 (mTORC1) inhibition, simultaneous targeting of mTORC1/2 may be more effective. In this study, we examined the interaction between the dual mTORC1/2 inhibitor OSI-027 and doxorubicin in vitro and in vivo. OSI-027 was found to reduce phosphorylation of both mTORC1 and mTORC2 substrates, including 4E-BP1, p70S6K, and AKT (Ser473), and inhibit HCC cell proliferation. Similar to OSI-027 treatment, knockdown of mTORC2 induced G0-G1 phase cell-cycle arrest. In contrast, rapamycin or knockdown of mTORC1 increased phosphorylation of AKT (Ser473), yet had little antiproliferative effect. Notably, OSI-027 synergized with doxorubicin for the antiproliferative efficacy in a manner dependent of MDR1 expression in HCC cells. The synergistic antitumor effect of OSI-027 and doxorubicin was also observed in a HCC xenograft mouse model. Moreover, AKT was required for OSI-027-induced cell-cycle arrest and downregulation of MDR1. Our findings provide a rationale for dual mTORC1/mTORC2 inhibitors, such as OSI-027, as monotherapy or in combination with cytotoxic agents to treat HCC. Mol Cancer Ther; 14(8); 1805-15. ©2015 AACR. PMID:26026051

  9. Genistein inhibits radiation-induced activation of NF-κB in prostate cancer cells promoting apoptosis and G2/M cell cycle arrest

    International Nuclear Information System (INIS)

    New cancer therapeutic strategies must be investigated that enhance prostate cancer treatment while minimizing associated toxicities. We have previously shown that genistein, the major isoflavone found in soy, enhanced prostate cancer radiotherapy in vitro and in vivo. In this study, we investigated the cellular and molecular interaction between genistein and radiation using PC-3 human prostate cancer cells. Tumor cell survival and progression was determined by clonogenic analysis, flow cytometry, EMSA analysis of NF-κB, and western blot analysis of cyclin B1, p21WAF1/Cip1, and cleaved PARP protein. Genistein combined with radiation caused greater inhibition in PC-3 colony formation compared to genistein or radiation alone. Treatment sequence of genistein followed by radiation and continuous exposure to genistein showed optimal effect. Cell cycle analysis demonstrated a significant dose- and time-dependent G2/M arrest induced by genistein and radiation that correlated with increased p21WAF1/Cip1 and decreased cyclin B1 expression. NF-κB activity was significantly decreased by genistein, yet increased by radiation. Radiation-induced activation of NF-κB activity was strongly inhibited by genistein pre-treatment. A significant and striking increase in cleaved PARP protein was measured following combined genistein and radiation treatment, indicating increased apoptosis. A mechanism of increased cell death by genistein and radiation is proposed to occur via inhibition of NF-κB, leading to altered expression of regulatory cell cycle proteins such as cyclin B and/or p21WAF1/Cip1, thus promoting G2/M arrest and increased radiosensitivity. These findings support the important and novel strategy of combining genistein with radiation for the treatment of prostate cancer

  10. Antiproliferative Effects of Alkaloids Isolated from the Tuber of Stephania venosa via the Induction of Cell Cycle Arrest in Mammalian Cancer Cell Lines

    Directory of Open Access Journals (Sweden)

    Sirinapa Nantapap

    2010-01-01

    Full Text Available Problem statement: S. venosa (Menispermaceae is used in traditional medicine. The constituents of S. venosa belonging to showed remarkable cytotoxic activity. According to previous research, S. venosa contains several alkaloids, such as protoberberine stephanine cyclanoline and N-methylstepholidine, kamaline, (+-N-carboxamidostepharine, (--O-methylstepharinosine, (--stepharinosine, aporphine (--O-acethylsukhodiamine and oxostephanosine. The chemical and biological investigations of this plant are interesting to bioassay-guided fractionation, particularly Antiproliferative effects via the induction of cell cycle arrest in mammalian cancer cell lines. Approach: The research was carried out to extract, isolate, purify and elucidate structure of the active compound from the tuber S. venosa. Most of the solvent extracts and isolated compound were evaluated with kinds of mammalian cancer cell lines for investigation on antiproliferative effects. Results: Four alkaloids, tetrahydropalmatine (1, crebanine (2 O-methylbulbocapnine (3 and N-methyltetrahydropalmatine (4 were isolated from the tuber of S. venosa. Charaterization of the compounds were carried out by extensive NMR studies using COSY, HMQC, HMBC and DEPT in addition to other spectroscopic methods. These compounds (1, 2 and 3 were showed evidence of the anticancer activities for cell proliferation inhibition in K562, K562/Adr, GLC4 and GLC4/Adr cell lines due to G0/G1 obstruction by compound 2 and 3 and negligible S phase arrest by compound 1. Conclusion: The result showed slightly increase in S phase by the effect of compound 1, beside the G0/G1 phase was blocked by compound 2 and 3.

  11. Deficiency of G1 regulators P53, P21Cip1 and/or pRb decreases hepatocyte sensitivity to TGFβ cell cycle arrest

    International Nuclear Information System (INIS)

    TGFβ is critical to control hepatocyte proliferation by inducing G1-growth arrest through multiple pathways leading to inhibition of E2F transcription activity. The retinoblastoma protein pRb is a key controller of E2F activity and G1/S transition which can be inhibited in viral hepatitis. It is not known whether the impairment of pRb would alter the growth inhibitory potential of TGFβ in disease. We asked how Rb-deficiency would affect responses to TGFβ-induced cell cycle arrest. Primary hepatocytes isolated from Rb-floxed mice were infected with an adenovirus expressing CRE-recombinase to delete the Rb gene. In control cells treatment with TGFβ prevented cells to enter S phase via decreased cMYC activity, activation of P16INK4A and P21Cip and reduction of E2F activity. In Rb-null hepatocytes, cMYC activity decreased slightly but P16INK4A was not activated and the great majority of cells continued cycling. Rb is therefore central to TGFβ-induced cell cycle arrest in hepatocytes. However some Rb-null hepatocytes remained sensitive to TGFβ-induced cell cycle arrest. As these hepatocytes expressed very high levels of P21Cip1 and P53 we investigated whether these proteins regulate pRb-independent signaling to cell cycle arrest by evaluating the consequences of disruption of p53 and p21Cip1. Hepatocytes deficient in p53 or p21Cip1 showed diminished growth inhibition by TGFβ. Double deficiency had a similar impact showing that in cells containing functional pRb; P21Cip and P53 work through the same pathway to regulate G1/S in response to TGFβ. In Rb-deficient cells however, p53 but not p21Cip deficiency had an additive effect highlighting a pRb-independent-P53-dependent effector pathway of inhibition of E2F activity. The present results show that otherwise genetically normal hepatocytes with disabled p53, p21Cip1 or Rb genes respond less well to the antiproliferative effects of TGFβ. As the function of these critical cellular proteins can be impaired by common

  12. Deficiency of G1 regulators P53, P21Cip1 and/or pRb decreases hepatocyte sensitivity to TGFβ cell cycle arrest

    Directory of Open Access Journals (Sweden)

    Harrison David J

    2007-11-01

    Full Text Available Abstract Background TGFβ is critical to control hepatocyte proliferation by inducing G1-growth arrest through multiple pathways leading to inhibition of E2F transcription activity. The retinoblastoma protein pRb is a key controller of E2F activity and G1/S transition which can be inhibited in viral hepatitis. It is not known whether the impairment of pRb would alter the growth inhibitory potential of TGFβ in disease. We asked how Rb-deficiency would affect responses to TGFβ-induced cell cycle arrest. Results Primary hepatocytes isolated from Rb-floxed mice were infected with an adenovirus expressing CRE-recombinase to delete the Rb gene. In control cells treatment with TGFβ prevented cells to enter S phase via decreased cMYC activity, activation of P16INK4A and P21Cip and reduction of E2F activity. In Rb-null hepatocytes, cMYC activity decreased slightly but P16INK4A was not activated and the great majority of cells continued cycling. Rb is therefore central to TGFβ-induced cell cycle arrest in hepatocytes. However some Rb-null hepatocytes remained sensitive to TGFβ-induced cell cycle arrest. As these hepatocytes expressed very high levels of P21Cip1 and P53 we investigated whether these proteins regulate pRb-independent signaling to cell cycle arrest by evaluating the consequences of disruption of p53 and p21Cip1. Hepatocytes deficient in p53 or p21Cip1 showed diminished growth inhibition by TGFβ. Double deficiency had a similar impact showing that in cells containing functional pRb; P21Cip and P53 work through the same pathway to regulate G1/S in response to TGFβ. In Rb-deficient cells however, p53 but not p21Cip deficiency had an additive effect highlighting a pRb-independent-P53-dependent effector pathway of inhibition of E2F activity. Conclusion The present results show that otherwise genetically normal hepatocytes with disabled p53, p21Cip1 or Rb genes respond less well to the antiproliferative effects of TGFβ. As the function of

  13. Disrupted cell cycle arrest and reduced proliferation in corneal fibroblasts from GCD2 patients: A potential role for altered autophagy flux

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Seung-il; Dadakhujaev, Shorafidinkhuja; Maeng, Yong-Sun; Ahn, So-yeon; Kim, Tae-im [Department of Ophthalmology, Severance Hospital, Yonsei University College of Medicine, Seoul (Korea, Republic of); Corneal Dystrophy Research Institute, Yonsei University College of Medicine, Seoul (Korea, Republic of); Kim, Eung Kweon, E-mail: eungkkim@yuhs.ac [Department of Ophthalmology, Severance Hospital, Yonsei University College of Medicine, Seoul (Korea, Republic of); Corneal Dystrophy Research Institute, Yonsei University College of Medicine, Seoul (Korea, Republic of); BK21 Plus Project for Medical Science and Severance Biomedical Science Institute, Yonsei University College of Medicine, Seoul (Korea, Republic of)

    2015-01-02

    Highlights: • Reduced cell proliferation in granular corneal dystrophy type 2. • Abnormal cell cycle arrest by defective autophagy. • Decreased Cyclin A1, B1, and D1 in Atg7 gene knockout cells. • Increase in p16 and p27 expressions were observed in Atg7 gene knockout cells. - Abstract: This study investigates the role of impaired proliferation, altered cell cycle arrest, and defective autophagy flux of corneal fibroblasts in granular corneal dystrophy type 2 (GCD2) pathogenesis. The proliferation rates of homozygous (HO) GCD2 corneal fibroblasts at 72 h, 96 h, and 120 h were significantly lower (1.102 ± 0.027, 1.397 ± 0.039, and 1.527 ± 0.056, respectively) than those observed for the wild-type (WT) controls (1.441 ± 0.029, 1.758 ± 0.043, and 2.003 ± 0.046, respectively). Flow cytometry indicated a decreased G{sub 1} cell cycle progression and the accumulation of cells in the S and G{sub 2}/M phases in GCD2 cells. These accumulations were associated with decreased levels of Cyclin A1, B1, and E1, and increased expression of p16 and p27. p21 and p53 expression was also significantly lower in GCD2 cells compared to the WT. Interestingly, treatment with the autophagy flux inhibitor, bafilomycin A{sub 1}, resulted in similarly decreased Cyclin A1, B1, D1, and p53 expression in WT fibroblasts. Furthermore, similar findings, including a decrease in Cyclin A1, B1, and D1 and an increase in p16 and p27 expression were observed in autophagy-related 7 (Atg7; known to be essential for autophagy) gene knockout cells. These data provide new insight concerning the role of autophagy in cell cycle arrest and cellular proliferation, uncovering a number of novel therapeutic possibilities for GCD2 treatment.

  14. Disrupted cell cycle arrest and reduced proliferation in corneal fibroblasts from GCD2 patients: A potential role for altered autophagy flux

    International Nuclear Information System (INIS)

    Highlights: • Reduced cell proliferation in granular corneal dystrophy type 2. • Abnormal cell cycle arrest by defective autophagy. • Decreased Cyclin A1, B1, and D1 in Atg7 gene knockout cells. • Increase in p16 and p27 expressions were observed in Atg7 gene knockout cells. - Abstract: This study investigates the role of impaired proliferation, altered cell cycle arrest, and defective autophagy flux of corneal fibroblasts in granular corneal dystrophy type 2 (GCD2) pathogenesis. The proliferation rates of homozygous (HO) GCD2 corneal fibroblasts at 72 h, 96 h, and 120 h were significantly lower (1.102 ± 0.027, 1.397 ± 0.039, and 1.527 ± 0.056, respectively) than those observed for the wild-type (WT) controls (1.441 ± 0.029, 1.758 ± 0.043, and 2.003 ± 0.046, respectively). Flow cytometry indicated a decreased G1 cell cycle progression and the accumulation of cells in the S and G2/M phases in GCD2 cells. These accumulations were associated with decreased levels of Cyclin A1, B1, and E1, and increased expression of p16 and p27. p21 and p53 expression was also significantly lower in GCD2 cells compared to the WT. Interestingly, treatment with the autophagy flux inhibitor, bafilomycin A1, resulted in similarly decreased Cyclin A1, B1, D1, and p53 expression in WT fibroblasts. Furthermore, similar findings, including a decrease in Cyclin A1, B1, and D1 and an increase in p16 and p27 expression were observed in autophagy-related 7 (Atg7; known to be essential for autophagy) gene knockout cells. These data provide new insight concerning the role of autophagy in cell cycle arrest and cellular proliferation, uncovering a number of novel therapeutic possibilities for GCD2 treatment

  15. Notch Signaling Activation in Cervical Cancer Cells Induces Cell Growth Arrest with the Involvement of the Nuclear Receptor NR4A2

    Science.gov (United States)

    Sun, Lichun; Liu, Mingqiu; Sun, Guang-Chun; Yang, Xu; Qian, Qingqing; Feng, Shuyu; Mackey, L. Vienna; Coy, David H.

    2016-01-01

    Cervical cancer is a second leading cancer death in women world-wide, with most cases in less developed countries. Notch signaling is highly conserved with its involvement in many cancers. In the present study, we established stable cervical cell lines with Notch activation and inactivation and found that Notch activation played a suppressive role in cervical cancer cells. Meanwhile, the transient overexpression of the active intracellular domain of all four Notch receptors (ICN1, 2, 3, and 4) also induced the suppression of cervical cancer Hela cell growth. ICN1 also induced cell cycle arrest at phase G1. Notch1 signaling activation affected the expression of serial genes, especially the genes associated with cAMP signaling, with an increase of genes like THBS1, VCL, p63, c-Myc and SCG2, a decrease of genes like NR4A2, PCK2 and BCL-2. Particularly, The nuclear receptor NR4A2 was observed to induce cell proliferation via MTT assay and reduce cell apoptosis via FACS assay. Furthermore, NR4A2's activation could reverse ICN1-induced suppression of cell growth while erasing ICN1-induced increase of tumor suppressor p63. These findings support that Notch signaling mediates cervical cancer cell growth suppression with the involvement of nuclear receptor NR4A2. Notably, Notch/NR4A2/p63 signaling cascade possibly is a new signling pathway undisclosed. PMID:27471554

  16. Growth arrest of lung carcinoma cells (A549) by polyacrylate-anchored peroxovanadate by activating Rac1-NADPH oxidase signalling axis.

    Science.gov (United States)

    Chatterjee, Nirupama; Anwar, Tarique; Islam, Nashreen S; Ramasarma, T; Ramakrishna, Gayatri

    2016-09-01

    Hydrogen peroxide is often required in sublethal, millimolar concentrations to show its oxidant effects on cells in culture as it is easily destroyed by cellular catalase. Previously, we had shown that diperoxovanadate, a physiologically stable peroxovanadium compound, can substitute H2O2 effectively in peroxidation reactions. We report here that peroxovanadate when anchored to polyacrylic acid (PAPV) becomes a highly potent inhibitor of growth of lung carcinoma cells (A549). The early events associated with PAPV treatment included cytoskeletal modifications, increase in GTPase activity of Rac1, accumulation of the reactive oxygen species, and also increase in phosphorylation of H2AX (γH2AX), a marker of DNA damage. These effects persisted even at 24 h after removal of the compound and culminated in increased levels of p53 and p21 together with growth arrest. The PAPV-mediated growth arrest was significantly abrogated in cells pre-treated with the N-acetylcysteine, Rac1 knocked down by siRNA and DPI an inhibitor of NADPH oxidase. In conclusion, our results show that polyacrylate derivative of peroxovanadate efficiently arrests growth of A549 cancerous cells by activating the axis of Rac1-NADPH oxidase leading to oxidative stress and DNA damage. PMID:27435854

  17. Novel Suicide Ligands of Tubulin Arrest Cancer Cells in S-Phase

    OpenAIRE

    Ashley Davis; Jian-Dong Jiang; Middleton, Kim M; Yue Wang; Imre Weisz; Yi-He Ling; J. George Bekesi

    1999-01-01

    It is presently accepted that the mechanism of action for all anti-tumor tubulin ligands involves the perturbation of microtubule dynamics during the G2/M phase of cell division and subsequent entry into apoptosis 1]. In this report, we challenge the established dogma by describing a unique mechanism of action caused by a novel series of tubulin ligands, halogenated derivatives of acetamido benzoyl ethyl ester. We have developed a suicide ligand for tubulin, which covalently attaches to the t...

  18. Novel Suicide Ligands of Tubulin Arrest Cancer Cells in S-Phase1

    OpenAIRE

    Davis, Ashley; Jiang, Jian-Dong; Middleton, Kim M; Wang, Yue; Weisz, Imre; Ling, Yi-He; Bekesi, J George

    1999-01-01

    It is presently accepted that the mechanism of action for all anti-tumor tubulin ligands involves the perturbation of microtubule dynamics during the G2/M phase of cell division and subsequent entry into apoptosis [1]. In this report, we challenge the established dogma by describing a unique mechanism of action caused by a novel series of tubulin ligands, halogenated derivatives of acetamido benzoyl ethyl ester. We have developed a suicide ligand for tubulin, which covalently attaches to the ...

  19. Kefir induces cell-cycle arrest and apoptosis in HTLV-1-negative malignant T-lymphocytes

    OpenAIRE

    Katia Maalouf; Elias Baydoun; Sandra Rizk

    2011-01-01

    Katia Maalouf1, Elias Baydoun2, Sandra Rizk11Department of Natural Sciences, Lebanese American University, Beirut, Lebanon; 2Department of Biology, American University of Beirut, Beirut, LebanonBackground: Adult lymphoblastic leukemia (ALL) is a malignancy that occurs in white blood cells. The overall cure rate in children is 85%, whereas it is only 40% in adults. Kefir is an important probiotic that contains many bioactive ingredients, which give it unique health benefits. It has been shown ...

  20. Nanotechnology and mesenchymal stem cells with chondrocytes in prevention of partial growth plate arrest in pigs

    Czech Academy of Sciences Publication Activity Database

    Plánka, L.; Srnec, R.; Rauser, P.; Starý, D.; Filová, Eva; Jančář, J.; Juhásová, Jana; Křen, J.; Nečas, A.; Gál, P.

    2012-01-01

    Roč. 156, č. 2 (2012), s. 128-134. ISSN 1213-8118 R&D Projects: GA MZd(CZ) NS9896 Institutional research plan: CEZ:AV0Z50390512; CEZ:AV0Z50450515 Institutional support: RVO:68378041 ; RVO:67985904 Keywords : mesenchymal stem cells * growth plate defect * bone bridge Subject RIV: FI - Traumatology, Orthopedics Impact factor: 0.990, year: 2012

  1. Like Mother,Like Daughter

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    On the road to maturity, one's parents always have a great degree of influence. Yang Yuying, a young singer, attributes much of her success to her mother Xiong Yonghong. The hard working mother has exerted an imperceptible influence on her daughter's attitude to life with her traditional Chinese virtues.

  2. Lung pathology and exposure to radon daughters

    International Nuclear Information System (INIS)

    The data presented suggest that the primary carcinogen of lung cancer in uranium miners is cigarette smoking because the incidence of lung cancer in noncigarette smokers is insignificant. In cigarette-smoking uranium miners, however, the incidence of cancer in those exposed to significant amounts of radon daughters is higher than in the smoking, nonmining population. This suggests that radon is an additive carcinogen if the lung has been injured by the cigarette-smoking carcinogen. Preliminary studies measuring DNA, T cells, and rosette inhibition immunological studies indicate closer monitoring of uranium miners' health during this occupation may be justified

  3. Induction of cell cycle arrest at G1 and S phases and cAMP-dependent differentiation in C6 glioma by low concentration of cycloheximide

    Directory of Open Access Journals (Sweden)

    Zhang Samuel S

    2010-12-01

    Full Text Available Abstract Background Differentiation therapy has been shown effective in treatment of several types of cancer cells and may prove to be effective in treatment of glioblastoma multiforme, the most common and most aggressive primary brain tumor. Although extensively used as a reagent to inhibit protein synthesis in mammalian cells, whether cycloheximide treatment leads to glioma cell differentiation has not been reported. Methods C6 glioma cell was treated with or without cycloheximide at low concentrations (0.5-1 μg/ml for 1, 2 and 3 days. Cell proliferation rate was assessed by direct cell counting and colony formation assays. Apoptosis was assessed by Hoechst 33258 staining and FACS analysis. Changes in several cell cycle regulators such as Cyclins D1 and E, PCNA and Ki67, and several apoptosis-related regulators such as p53, p-JNK, p-AKT, and PARP were determined by Western blot analysis. C6 glioma differentiation was determined by morphological characterization, immunostaining and Western blot analysis on upregulation of GFAP and o p-STAT3 expression, and upregulation of intracellular cAMP. Results Treatment of C6 cell with low concentration of cycloheximide inhibited cell proliferation and depleted cells at both G2 and M phases, suggesting blockade at G1 and S phases. While no cell death was observed, cells underwent profound morphological transformation that indicated cell differentiation. Western blotting and immunostaining analyses further indicated that changes in expression of several cell cycle regulators and the differentiation marker GFAP were accompanied with cycloheximide-induced cell cycle arrest and cell differentiation. Increase in intracellular cAMP, a known promoter for C6 cell differentiation, was found to be elevated and required for cycloheximide-promoted C6 cell differentiation. Conclusion Our results suggest that partial inhibition of protein synthesis in C6 glioma by low concentration of cycloheximide induces cell cycle

  4. Induction of cell cycle arrest at G1 and S phases and cAMP-dependent differentiation in C6 glioma by low concentration of cycloheximide

    International Nuclear Information System (INIS)

    Differentiation therapy has been shown effective in treatment of several types of cancer cells and may prove to be effective in treatment of glioblastoma multiforme, the most common and most aggressive primary brain tumor. Although extensively used as a reagent to inhibit protein synthesis in mammalian cells, whether cycloheximide treatment leads to glioma cell differentiation has not been reported. C6 glioma cell was treated with or without cycloheximide at low concentrations (0.5-1 μg/ml) for 1, 2 and 3 days. Cell proliferation rate was assessed by direct cell counting and colony formation assays. Apoptosis was assessed by Hoechst 33258 staining and FACS analysis. Changes in several cell cycle regulators such as Cyclins D1 and E, PCNA and Ki67, and several apoptosis-related regulators such as p53, p-JNK, p-AKT, and PARP were determined by Western blot analysis. C6 glioma differentiation was determined by morphological characterization, immunostaining and Western blot analysis on upregulation of GFAP and o p-STAT3 expression, and upregulation of intracellular cAMP. Treatment of C6 cell with low concentration of cycloheximide inhibited cell proliferation and depleted cells at both G2 and M phases, suggesting blockade at G1 and S phases. While no cell death was observed, cells underwent profound morphological transformation that indicated cell differentiation. Western blotting and immunostaining analyses further indicated that changes in expression of several cell cycle regulators and the differentiation marker GFAP were accompanied with cycloheximide-induced cell cycle arrest and cell differentiation. Increase in intracellular cAMP, a known promoter for C6 cell differentiation, was found to be elevated and required for cycloheximide-promoted C6 cell differentiation. Our results suggest that partial inhibition of protein synthesis in C6 glioma by low concentration of cycloheximide induces cell cycle arrest at G1 and M phases and cAMP-dependent cell differentiation

  5. Classic swine fever virus NS2 protein leads to the induction of cell cycle arrest at S-phase and endoplasmic reticulum stress

    Directory of Open Access Journals (Sweden)

    He Lei

    2010-01-01

    Full Text Available Abstract Background Classical swine fever (CSF caused by virulent strains of Classical swine fever virus (CSFV is a haemorrhagic disease of pigs, characterized by disseminated intravascular coagulation, thrombocytopoenia and immunosuppression, and the swine endothelial vascular cell is one of the CSFV target cells. In this report, we investigated the previously unknown subcellular localization and function of CSFV NS2 protein by examining its effects on cell growth and cell cycle progression. Results Stable swine umbilical vein endothelial cell line (SUVEC expressing CSFV NS2 were established and showed that the protein localized to the endoplasmic reticulum (ER. Cellular analysis revealed that replication of NS2-expressing cell lines was inhibited by 20-30% due to cell cycle arrest at S-phase. The NS2 protein also induced ER stress and activated the nuclear transcription factor kappa B (NF-κB. A significant increase in cyclin A transcriptional levels was observed in NS2-expressing cells but was accompanied by a concomitant increase in the proteasomal degradation of cyclin A protein. Therefore, the induction of cell cycle arrest at S-phase by CSFV NS2 protein is associated with increased turnover of cyclin A protein rather than the down-regulation of cyclin A transcription. Conclusions All the data suggest that CSFV NS2 protein modulate the cellular growth and cell cycle progression through inducing the S-phase arrest and provide a cellular environment that is advantageous for viral replication. These findings provide novel information on the function of the poorly characterized CSFV NS2 protein.

  6. Crude extract of Rheum palmatum L. Induces cell cycle arrest S phase and apoptosis through mitochondrial-dependent pathways in U-2 OS human osteosarcoma cells.

    Science.gov (United States)

    Lin, Chin-Chung; Lee, Ming-Huei; Lin, Ju-Hwa; Lin, Meng-Liang; Chueh, Fu-Shin; Yu, Chien-Chih; Lin, Jing-Pin; Chou, Yu-Cheng; Hsu, Shu-Chun; Chung, Jing-Gung

    2016-08-01

    Cancer is the second cause of death in children. Osteosarcoma is the most common primary malignancy of solid bone cancer primarily affecting adolescents and young adults. In the Chinese population, the crude extract of Rheum palmatum L. (CERP) has been used for treating different diseases, including SARS, rheumatoid arthritis, coxsackievirus B3, and human colon cancer cell, pancreatic cancer. There are no reports on CERP and human osteosarcoma cells. The present study examined effects of CERP on cytotoxicity including cell cycle distribution and cell death (apoptosis) in U-2 OS human osteosarcoma cells. CERP significantly induced S phase arrest in U-2 OS cells in a dose-dependent. CERP produced DNA damage and DNA condensation. Other effects of CERP were stimulation of ROS and Ca(2+) , mitochondria impairment, and activation of caspase-3, -8, and -9. CERP increased the levels of Bax, Bak, Bad, cyclin B, Fas, PARP, GRP78, GADD153, AIF, Endo G, Calpain-2, p21, and p27, but decreased the levels of Bcl-2, BCL-X, XIAP, Akt, CDC25A, CDK2, Cyclin A, and Cyclin E of U-2 OS cells. It was also observed that CERP promoted the expression of AIF, Endo G, GADD153, and cytochrome c. These results indicate that CERP has anticancer effects in vitro and provide the foundation for in vivo studies of animal models of osteosarcoma. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 957-969, 2016. PMID:25689151

  7. Fucoidan induces G1 arrest of the cell cycle in EJ human bladder cancer cells through down-regulation of pRB phosphorylation

    Directory of Open Access Journals (Sweden)

    Hye Young Park

    2015-06-01

    Full Text Available AbstractFucoidan, a sulfated polysaccharide found in marine algae and brown seaweeds, has been shown to inhibit the in vitro growth of human cancer cells. This study was conducted in cultured human bladder cancer EJ cells to elucidate the possible mechanisms by which fucoidan exerts its anti-proliferative activity, which until now has remained poorly understood. Fucoidan treatment of EJ cells resulted in dose-dependent inhibition of cell growth and induced apoptotic cell death. Flow cytometric analysis revealed that fucoidan led to G1 arrest in cell cycle progression. It was associated with down-regulation of cyclin D1, cyclin E, and cyclin-dependent-kinases (Cdks in a concentration-dependent manner, without any change in Cdk inhibitors, such as p21 and p27. Furthermore, dephosphorylation of retinoblastoma protein (pRB by this compound was associated with enhanced binding of pRB with the transcription factors E2F-1 and E2F-4. Overall, our results demonstrate that fucoidan possesses anticancer activity potential against bladder cancer cells by inhibiting pRB phosphorylation.

  8. The immunomodulator PSK induces in vitro cytotoxic activity in tumour cell lines via arrest of cell cycle and induction of apoptosis

    International Nuclear Information System (INIS)

    Protein-bound polysaccharide (PSK) is derived from the CM-101 strain of the fungus Coriolus versicolor and has shown anticancer activity in vitro and in in vivo experimental models and human cancers. Several randomized clinical trials have demonstrated that PSK has great potential in adjuvant cancer therapy, with positive results in the adjuvant treatment of gastric, esophageal, colorectal, breast and lung cancers. These studies have suggested the efficacy of PSK as an immunomodulator of biological responses. The precise molecular mechanisms responsible for its biological activity have yet to be fully elucidated. The in vitro cytotoxic anti-tumour activity of PSK has been evaluated in various tumour cell lines derived from leukaemias, melanomas, fibrosarcomas and cervix, lung, pancreas and gastric cancers. Tumour cell proliferation in vitro was measured by BrdU incorporation and viable cell count. Effect of PSK on human peripheral blood lymphocyte (PBL) proliferation in vitro was also analyzed. Studies of cell cycle and apoptosis were performed in PSK-treated cells. PSK showed in vitro inhibition of tumour cell proliferation as measured by BrdU incorporation and viable cell count. The inhibition ranged from 22 to 84%. Inhibition mechanisms were identified as cell cycle arrest, with cell accumulation in G0/G1 phase and increase in apoptosis and caspase-3 expression. These results indicate that PSK has a direct cytotoxic activity in vitro, inhibiting tumour cell proliferation. In contrast, PSK shows a synergistic effect with IL-2 that increases PBL proliferation. These results indicate that PSK has cytotoxic activity in vitro on tumour cell lines. This new cytotoxic activity of PSK on tumour cells is independent of its previously described immunomodulatory activity on NK cells

  9. AZD2014 Radiosensitizes Oral Squamous Cell Carcinoma by Inhibiting AKT/mTOR Axis and Inducing G1/G2/M Cell Cycle Arrest.

    Directory of Open Access Journals (Sweden)

    Chih-Chia Yu

    Full Text Available Oral squamous cell carcinoma (OSCC is one of the most common malignant neoplasms in Taiwan. Activation of the mTOR signaling pathway has been linked to decreased radiation responsiveness in human oral cancer, thus it limits efficacy of radiotherapy. To address this question, we investigated the effect of AZD2014, a novel small molecular ATP-competitive inhibitor of mTORC1 and mTORC2 kinase, as a radiosensitizer in primary OSCC and OSCC-derived cell line models.We isolated primary tumor cells from OSCC tissues and cell lines. AZD2014 was administered with and without ionizing radiation. The radiosensitizing effect of AZD2014 were then assessed using cell viability assays, clonogenic survival assays, and cell cycle analyses. Western blotting was used to detect protein expression.Combination treatment with AZD2014 and irradiation resulted in significant reduction in OSCC cell line and primary OSCC cell colony formation due to the enhanced inhibition of AKT and both mTORC1 and mTORC2 activity. Pre-treatment with AZD2014 in irradiated oral cancer cells induced tumor cell cycle arrest at the G1 and G2/M phases, which led to disruption of cyclin D1-CDK4 and cyclin B1-CDC2 complexes. Moreover, AZD2014 synergized with radiation to promote both apoptosis and autophagy by increasing caspase-3 and LC3 in primary OSCC cells.These findings suggest that in irradiated OSCC cells, co-treatment with AZD2014, which targets mTORC1 and mTORC2 blockade, is an effective radiosensitizing strategy for oral squamous cell carcinoma.

  10. The immunomodulator PSK induces in vitro cytotoxic activity in tumour cell lines via arrest of cell cycle and induction of apoptosis

    Directory of Open Access Journals (Sweden)

    Garrido Federico

    2008-03-01

    Full Text Available Abstract Background Protein-bound polysaccharide (PSK is derived from the CM-101 strain of the fungus Coriolus versicolor and has shown anticancer activity in vitro and in in vivo experimental models and human cancers. Several randomized clinical trials have demonstrated that PSK has great potential in adjuvant cancer therapy, with positive results in the adjuvant treatment of gastric, esophageal, colorectal, breast and lung cancers. These studies have suggested the efficacy of PSK as an immunomodulator of biological responses. The precise molecular mechanisms responsible for its biological activity have yet to be fully elucidated. Methods The in vitro cytotoxic anti-tumour activity of PSK has been evaluated in various tumour cell lines derived from leukaemias, melanomas, fibrosarcomas and cervix, lung, pancreas and gastric cancers. Tumour cell proliferation in vitro was measured by BrdU incorporation and viable cell count. Effect of PSK on human peripheral blood lymphocyte (PBL proliferation in vitro was also analyzed. Studies of cell cycle and apoptosis were performed in PSK-treated cells. Results PSK showed in vitro inhibition of tumour cell proliferation as measured by BrdU incorporation and viable cell count. The inhibition ranged from 22 to 84%. Inhibition mechanisms were identified as cell cycle arrest, with cell accumulation in G0/G1 phase and increase in apoptosis and caspase-3 expression. These results indicate that PSK has a direct cytotoxic activity in vitro, inhibiting tumour cell proliferation. In contrast, PSK shows a synergistic effect with IL-2 that increases PBL proliferation. Conclusion These results indicate that PSK has cytotoxic activity in vitro on tumour cell lines. This new cytotoxic activity of PSK on tumour cells is independent of its previously described immunomodulatory activity on NK cells.

  11. Plant HDAC inhibitor chrysin arrest cell growth and induce p21WAF1 by altering chromatin of STAT response element in A375 cells

    Directory of Open Access Journals (Sweden)

    Pal-Bhadra Manika

    2012-05-01

    Full Text Available Abstract Background Chrysin and its analogues, belongs to flavonoid family and possess potential anti-tumour activity. The aim of this study is to determine the molecular mechanism by which chrysin controls cell growth and induce apoptosis in A375 cells. Methods Effect of chrysin and its analogues on cell viability and cell cycle analysis was determined by MTT assay and flowcytometry. A series of Western blots was performed to determine the effect of chrysin on important cell cycle regulatory proteins (Cdk2, cyclin D1, p53, p21, p27. The fluorimetry and calorimetry based assays was conducted for characterization of chrysin as HDAC inhibitor. The changes in histone tail modification such as acetylation and methylation was studied after chrysin treatment was estimated by immuno-fluorescence and western blot analysis. The expression of Bcl-xL, survivin and caspase-3 was estimated in chrysin treated cells. The effect of chrysin on p21 promoter activity was studied by luciferase and ChIP assays. Results Chrysin cause G1 cell cycle arrest and found to inhibit HDAC-2 and HDAC-8. Chrysin treated cells have shown increase in the levels of H3acK14, H4acK12, H4acK16 and decrease in H3me2K9 methylation. The p21 induction by chrysin treatment was found to be independent of p53 status. The chromatin remodelling at p21WAF1 promoter induces p21 activity, increased STAT-1 expression and epigenetic modifications that are responsible for ultimate cell cycle arrest and apoptosis. Conclusion Chrysin shows in vitro anti-cancer activity that is correlated with induction of histone hyperacetylation and possible recruitment of STAT-1, 3, 5 proteins at STAT (−692 to −684 region of p21 promoter. Our results also support an unexpected action of chrysin on the chromatin organization of p21WAF1 promoter through histone methylation and hyper-acetylation. It proposes previously unknown sequence specific chromatin modulations in the STAT responsive elements for regulating

  12. Inhibition of human prostate cancer cells proliferation by a selective alpha1-adrenoceptor antagonist labedipinedilol-A involves cell cycle arrest and apoptosis

    International Nuclear Information System (INIS)

    In this research, we conducted an in vitro analysis to evaluate the prostate cancer cells response to labedipinedilol-A in order to determine the effect of this selective α1-adrenoceptor antagonist to suppress prostate cancer cell growth by affecting cell proliferation and apoptosis. Here, we report that treatment of androgen-sensitive (LNCaP) and androgen-insensitive (PC-3) prostate cancer cells with labedipinedilol-A inhibited cell proliferation in concentration-dependent and time-dependent manners. Moreover, norepinephrine-stimulated proliferation of both cell lines are markedly inhibited by labedipinedilol-A. The probable involvement of α1-adrenoceptors in this cellular response is suggested. Labedipinedilol-A-induced growth inhibition was associated with G0/G1 arrest, and G2/M arrest depending upon concentrations. Cell cycle blockade was associated with reduced amounts of cyclin D1/2, cyclin E, Cdk2, Cdk4, and Cdk6 and increased levels of the Cdk inhibitory proteins (Cip1/p21 and Kip1/p27). In addition, labedipinedilol-A also induced apoptosis in PC-3 cells, as determined by using Hoechst 33342 staining, DNA fragmentation, and Annexin V staining assay. Furthermore, labedipinedilol-A triggered the mitochondrial apoptotic pathway, as indicated by increasing the expression of Bax, but decreasing the level of Bcl-2, resulting in mitochondrial membrane potential loss, cytochrome c release, and activation of caspase-9 and -3. We further investigated the role of MAPK cascades in the anti-proliferative and apoptosis effects of labedipinedilol-A, and confirmed that labedipinedilol-A could activate JNK1/2 but not p38 in both cell lines. Unlike JNK1/2, however, labedipinedilol-A treatment resulted in down-regulation of phospho-ERK1/2 expression. We concluded that labedipinedilol-A possessed the growth-suppressive and apoptotic effects on LNCaP and PC-3 cells by its α1-adrenoceptor blockade, and the apoptotic effects of labedipinedilol-A primarily through caspases and

  13. Plant HDAC inhibitor chrysin arrest cell growth and induce p21WAF1 by altering chromatin of STAT response element in A375 cells

    International Nuclear Information System (INIS)

    Chrysin and its analogues, belongs to flavonoid family and possess potential anti-tumour activity. The aim of this study is to determine the molecular mechanism by which chrysin controls cell growth and induce apoptosis in A375 cells. Effect of chrysin and its analogues on cell viability and cell cycle analysis was determined by MTT assay and flowcytometry. A series of Western blots was performed to determine the effect of chrysin on important cell cycle regulatory proteins (Cdk2, cyclin D1, p53, p21, p27). The fluorimetry and calorimetry based assays was conducted for characterization of chrysin as HDAC inhibitor. The changes in histone tail modification such as acetylation and methylation was studied after chrysin treatment was estimated by immuno-fluorescence and western blot analysis. The expression of Bcl-xL, survivin and caspase-3 was estimated in chrysin treated cells. The effect of chrysin on p21 promoter activity was studied by luciferase and ChIP assays. Chrysin cause G1 cell cycle arrest and found to inhibit HDAC-2 and HDAC-8. Chrysin treated cells have shown increase in the levels of H3acK14, H4acK12, H4acK16 and decrease in H3me2K9 methylation. The p21 induction by chrysin treatment was found to be independent of p53 status. The chromatin remodelling at p21WAF1 promoter induces p21 activity, increased STAT-1 expression and epigenetic modifications that are responsible for ultimate cell cycle arrest and apoptosis. Chrysin shows in vitro anti-cancer activity that is correlated with induction of histone hyperacetylation and possible recruitment of STAT-1, 3, 5 proteins at STAT (−692 to −684) region of p21 promoter. Our results also support an unexpected action of chrysin on the chromatin organization of p21WAF1 promoter through histone methylation and hyper-acetylation. It proposes previously unknown sequence specific chromatin modulations in the STAT responsive elements for regulating cell cycle progression negatively via the induction of the CDK

  14. Identification of MicroRNAs Involved in Growth Arrest and Apoptosis in Hydrogen Peroxide-Treated Human Hepatocellular Carcinoma Cell Line HepG2

    Directory of Open Access Journals (Sweden)

    Yuan Luo

    2016-01-01

    Full Text Available Although both oxidative stress and microRNAs (miRNAs play vital roles in physiological and pathological processes, little is known about the interactions between them. In this study, we first described the regulation of H2O2 in cell viability, proliferation, cycle, and apoptosis of human hepatocellular carcinoma cell line HepG2. Then, miRNAs expression was profiled after H2O2 treatment. The results showed that high concentration of H2O2 (600 μM could decrease cell viability, inhibit cell proliferation, induce cell cycle arrest, and finally promote cell apoptosis. Conversely, no significant effects could be found under treatment with low concentration (30 μM. miRNAs array analysis identified 131 differentially expressed miRNAs (125 were upregulated and 6 were downregulated and predicted 13504 putative target genes of the deregulated miRNAs. Gene ontology (GO analysis revealed that the putative target genes were associated with H2O2-induced cell growth arrest and apoptosis. The subsequent bioinformatics analysis indicated that H2O2-response pathways, including MAPK signaling pathway, apoptosis, and pathways in cancer and cell cycle, were significantly affected. Overall, these results provided comprehensive information on the biological function of H2O2 treatment in HepG2 cells. The identification of miRNAs and their putative targets may offer new diagnostic and therapeutic strategies for liver cancer.

  15. Cucurbitacin-I (JSI-124) activates the JNK/c-Jun signaling pathway independent of apoptosis and cell cycle arrest in B Leukemic Cells

    International Nuclear Information System (INIS)

    Cucurbitacin-I (JSI-124) is potent inhibitor of JAK/STAT3 signaling pathway and has anti-tumor activity in a variety of cancer including B cell leukemia. However, other molecular targets of JSI-124 beyond the JAK/STAT3 pathway are not fully understood. BJAB, I-83, NALM-6 and primary CLL cells were treated with JSI-124 as indicated. Apoptosis was measured using flow cytometry for accumulation of sub-G1 phase cells (indicator of apoptosis) and Annexin V/PI staining. Cell cycle was analyzed by FACS for DNA content of G1 and G2 phases. Changes in phosphorylation and protein expression of p38, Erk1/2, JNK, c-Jun, and XIAP were detected by Western blot analysis. STAT3 and c-Jun genes were knocked out using siRNA transfection. VEGF expression was determined by mRNA and protein levels by RT-PCR and western blotting. Streptavidin Pull-Down Assay was used to determine c-Jun binding to the AP-1 DNA binding site. Herein, we show that JSI-124 activates c-Jun N-terminal kinase (JNK) and increases both the expression and serine phosphorylation of c-Jun protein in the B leukemic cell lines BJAB, I-83 and NALM-6. JSI-124 also activated MAPK p38 and MAPK Erk1/2 albeit at lower levels than JNK activation. Inhibition of the JNK signaling pathway failed to effect cell cycle arrest or apoptosis induced by JSI-124 but repressed JSI-124 induced c-Jun expression in these leukemia cells. The JNK pathway activation c-Jun leads to transcriptional activation of many genes. Treatment of BJAB, I-83, and NALM-6 cells with JSI-124 lead to an increase of Vascular Endothelial Growth Factor (VEGF) at both the mRNA and protein level. Knockdown of c-Jun expression and inhibition of JNK activation significantly blocked JSI-124 induced VEGF expression. Pretreatment with recombinant VEGF reduced JSI-124 induced apoptosis. Taken together, our data demonstrates that JSI-124 activates the JNK signaling pathway independent of apoptosis and cell cycle arrest, leading to increased VEGF expression

  16. Overexpression of USF Increases TGF-β1 Protein Levels, But G1 Phase Arrest was not Induced in FRTL-5 Cells

    OpenAIRE

    Kim, Keun-Sook; Jung, Hye Seung; Chung, Yun Jae; Jung, Tae Sik; Jang, Hye Won; Lee, Myung-Shik; Kim, Kwang-Won; Chung, Jae Hoon

    2008-01-01

    Transforming growth factor-β1 (TGF-β1) is a potent inhibitor of cellular growth and proliferation by G1 phase arrest or apoptosis. We investigated the association of TGF-β1 with the anti-proliferative effect of upstream stimulatory factor (USF) in Fischer rat thyroid cell line (FRTL-5) cells. [Methyl-3H] thymidine uptake was measured after treatment of FRTL-5 cells with TGF-β1 to identify its anti-proliferative effect. USF-1 and USF-2 proteins were in vitro translated, and an electrophoretic ...

  17. The long non-coding RNA HOTAIR promotes the proliferation of serous ovarian cancer cells through the regulation of cell cycle arrest and apoptosis

    Energy Technology Data Exchange (ETDEWEB)

    Qiu, Jun-jun [Department of Gynecology, Obstetrics and Gynecology Hospital, Fudan University, 419 Fangxie Road, Shanghai 200011 (China); Department of Obstetrics and Gynecology of Shanghai Medical College, Fudan University, 138 Yixueyuan Road, Shanghai 200032 (China); Shanghai Key Laboratory of Female Reproductive Endocrine-Related Diseases, 413 Zhaozhou Road, Shanghai 200011 (China); Wang, Yan [Cancer Institute, Fudan University Shanghai Cancer Center, 270 Dong' an Road, Shanghai 200032 (China); Department of Oncology, Shanghai Medical College, Fudan University, 130 Dong' an Road, Shanghai 200032 (China); Ding, Jing-xin; Jin, Hong-yan [Department of Gynecology, Obstetrics and Gynecology Hospital, Fudan University, 419 Fangxie Road, Shanghai 200011 (China); Department of Obstetrics and Gynecology of Shanghai Medical College, Fudan University, 138 Yixueyuan Road, Shanghai 200032 (China); Shanghai Key Laboratory of Female Reproductive Endocrine-Related Diseases, 413 Zhaozhou Road, Shanghai 200011 (China); Yang, Gong, E-mail: yanggong@fudan.edu.cn [Cancer Institute, Fudan University Shanghai Cancer Center, 270 Dong' an Road, Shanghai 200032 (China); Department of Oncology, Shanghai Medical College, Fudan University, 130 Dong' an Road, Shanghai 200032 (China); Hua, Ke-qin, E-mail: huakeqin@126.com [Department of Gynecology, Obstetrics and Gynecology Hospital, Fudan University, 419 Fangxie Road, Shanghai 200011 (China); Department of Obstetrics and Gynecology of Shanghai Medical College, Fudan University, 138 Yixueyuan Road, Shanghai 200032 (China); Shanghai Key Laboratory of Female Reproductive Endocrine-Related Diseases, 413 Zhaozhou Road, Shanghai 200011 (China)

    2015-05-01

    HOX transcript antisense RNA (HOTAIR) is a well-known long non-coding RNA (lncRNA) whose dysregulation correlates with poor prognosis and malignant progression in many forms of cancer. Here, we investigate the expression pattern, clinical significance, and biological function of HOTAIR in serous ovarian cancer (SOC). Clinically, we found that HOTAIR levels were overexpressed in SOC tissues compared with normal controls and that HOTAIR overexpression was correlated with an advanced FIGO stage and a high histological grade. Multivariate analysis revealed that HOTAIR is an independent prognostic factor for predicting overall survival in SOC patients. We demonstrated that HOTAIR silencing inhibited A2780 and OVCA429 SOC cell proliferation in vitro and that the anti-proliferative effects of HOTAIR silencing also occurred in vivo. Further investigation into the mechanisms responsible for the growth inhibitory effects by HOTAIR silencing revealed that its knockdown resulted in the induction of cell cycle arrest and apoptosis through certain cell cycle-related and apoptosis-related proteins. Together, these results highlight a critical role of HOTAIR in SOC cell proliferation and contribute to a better understanding of the importance of dysregulated lncRNAs in SOC progression. - Highlights: • HOTAIR overexpression correlates with an aggressive tumour phenotype and a poor prognosis in SOC. • HOTAIR promotes SOC cell proliferation both in vitro and in vivo. • The proliferative role of HOTAIR is associated with regulation of the cell cycle and apoptosis.

  18. Two new isoquinoline alkaloids from Scolopendra subspinipes mutilans induce cell cycle arrest and apoptosis in human glioma cancer U87 cells.

    Science.gov (United States)

    Ding, Dan; Guo, Ya-Ru; Wu, Rui-Ling; Qi, Wei-Yan; Xu, Han-Mei

    2016-04-01

    Two new isoquinoline alkaloids 1-2 and seven known compounds 3-9 were isolated from the ethanol extract of centipede Scolopendra subspinipes mutilans L. Koch. The structures were elucidated by a combination of spectroscopic analyses including 1D and 2D NMR, and HRESIMS. Compounds 1-2 exhibited good cytotoxicity with IC50 values ranging from 1.19 to 31.28μM against six human cancer cell lines and low cytotoxicity against human normal liver L-02 cell lines, suggesting that compounds 1-2 had high specific cytotoxicity on human cancer cell lines. Further analyses showed that compounds 1-2 inhibited U87 cells proliferation by arresting cell cycle progress at G0/G1 phase and inducing apoptosis through loss of mitochondrial membrane potential (MMP), activation of caspase 9/3 and down-regulation of the Bcl-2/Bax protein ratio. The results suggest that compounds 1-2 induce apoptosis in U87 cells through the mitochondria apoptosis pathway, and they deserve further research as potential anti-glioma cancer agents. PMID:26947248

  19. The long non-coding RNA HOTAIR promotes the proliferation of serous ovarian cancer cells through the regulation of cell cycle arrest and apoptosis

    International Nuclear Information System (INIS)

    HOX transcript antisense RNA (HOTAIR) is a well-known long non-coding RNA (lncRNA) whose dysregulation correlates with poor prognosis and malignant progression in many forms of cancer. Here, we investigate the expression pattern, clinical significance, and biological function of HOTAIR in serous ovarian cancer (SOC). Clinically, we found that HOTAIR levels were overexpressed in SOC tissues compared with normal controls and that HOTAIR overexpression was correlated with an advanced FIGO stage and a high histological grade. Multivariate analysis revealed that HOTAIR is an independent prognostic factor for predicting overall survival in SOC patients. We demonstrated that HOTAIR silencing inhibited A2780 and OVCA429 SOC cell proliferation in vitro and that the anti-proliferative effects of HOTAIR silencing also occurred in vivo. Further investigation into the mechanisms responsible for the growth inhibitory effects by HOTAIR silencing revealed that its knockdown resulted in the induction of cell cycle arrest and apoptosis through certain cell cycle-related and apoptosis-related proteins. Together, these results highlight a critical role of HOTAIR in SOC cell proliferation and contribute to a better understanding of the importance of dysregulated lncRNAs in SOC progression. - Highlights: • HOTAIR overexpression correlates with an aggressive tumour phenotype and a poor prognosis in SOC. • HOTAIR promotes SOC cell proliferation both in vitro and in vivo. • The proliferative role of HOTAIR is associated with regulation of the cell cycle and apoptosis

  20. Nexrutine inhibits survival and induces G1 cell cycle arrest, which is associated with apoptosis or autophagy depending on the breast cancer cell line.

    Science.gov (United States)

    Yan, Guang; Lanza-Jacoby, Susan; Wang, Chenguang

    2014-01-01

    Breast cancers that are estrogen receptor (ER) negative or are ER negative with ErbB2/HER-2 overexpression have a poor prognosis, which emphasizes the importance of developing compounds for preventing breast cancer. Nexrutine, an herbal extract from the plant Phellodendron amurense, has been used for centuries in Asian medicine to treat inflammation, gastroenteritis, abdominal pain, and diarrhea. In this study we investigated the anticancer effects of Nexrutine on ER negative breast cancer cell lines that are positive or negative for HER-2. Nexrutine decreased the activities of 2 potential targets of breast cancer, cyclooxygenase (COX)-2, and peroxisome proliferators activated receptor gamma (PPARγ). The antiinflammatory effects of Nexrutine were evident with decreased prostaglandin (PG)E2 production, protein expression of microsomal PGE2 synthase (mPGES), and PPARγ. Nexrutine decreased cell survival and induced a G1 cell cycle arrest in SkBr3 and MDA-MB 231 cells, which were associated with reduced protein expression of Cyclin D1 and cdk2 along with increased protein expression of p21 and p27. The growth-inhibitory effect of Nexrutine was associated with apoptosis in SkBr3 cells and autophagy in MDA-MB231 cells. Based on these findings, we propose that Nexrutine may provide a novel approach for protection against breast cancer. PMID:24206214

  1. Ethanol extract of Innotus obliquus (Chaga mushroom) induces G1 cell cycle arrest in HT-29 human colon cancer cells

    OpenAIRE

    Lee, Hyun Sook; Kim, Eun Ji; Kim, Sun Hyo

    2015-01-01

    BACKGROUND/OBJECTIVES Inonotus obliquus (I. obliquus, Chaga mushroom) has long been used as a folk medicine to treat cancer. In the present study, we examined whether or not ethanol extract of I. obliquus (EEIO) inhibits cell cycle progression in HT-29 human colon cancer cells, in addition to its mechanism of action. MATERIALS/METHODS To examine the effects of Inonotus obliquus on the cell cycle progression and the molecular mechanism in colon cancer cells, HT-29 human colon cancer cells were...

  2. P53-mediated cell cycle arrest and apoptosis through a caspase-3-independent, but caspase-9-dependent pathway in oridonin-treated MCF-7 human breast cancer cells

    Institute of Scientific and Technical Information of China (English)

    Qiao CUI; Jing-hua YU; Jin-nan WU; Shin-ichi TASHIRO; Satoshi ONODERA; Mutsuhiko MINAMI; Takashi IKEJIMA

    2007-01-01

    Aim: To study the caspase-3-independent mechanisms in oridonin-induced MCF-7 human breast cancer cell apoptosis in vitro. Methods: The viability of oridonin-treated MCF-7 cells was measured by MTT (thiazole blue) assay. Apoptotic cells with condensed nuclei were visualized by phase contrast microscopy. Nucleoso-mal DNA fragmentation was assayed by agarose gel electrophoresis. The apoptotic ratio was determined by lactate dehydrogenase assay. Cell cycle alternation and mitochondrial membrane potential were measured by flow cytometric analysis. Bax, Bcl-2, caspase-3, caspase-9, heat shock protein (Hsp)90, p53, p-p53, p21, Poly (ADP-ribose) polymerase (PARP), and the inhibitor of caspase-activated Dnase (ICAD) protein expressions were detected by Western blot analysis. Results: Oridonin inhibited cell growth in a time- and dose-dependent manner. Cell cycle was altered through the upregulation of p53 and p21 protein expressions. Pan-caspase inhibitor Z-VAD-fmk and calpain inhibitor Ⅱ both decreased cell death ratio. Nucleosomal DNA fragmentation and the downregulation of △ψmit were detected in oridonin-induced MCF-7 cell apoptosis, which was involved in a postmitochondrial caspase-9-dependent pathway. Decreased Bcl-2 and Hsp90 expression levels and increased Bax and p21 expression levels were positively correlated with elevated levels of phosphorylated p53 phosphorylation. Moreover, PARP was partially cleaved by calpain rather than by capase-3. Conclusion: DNA damage provoked alternations in the mitochondrial and caspase-9 pathways as well as p53-mediated cell cycle arrest, but was not related to caspase-3 activity in oridonin-induced MCF-7 cells.

  3. Induction of G1 and G2/M cell cycle arrests by the dietary compound 3,3'-diindolylmethane in HT-29 human colon cancer cells

    Directory of Open Access Journals (Sweden)

    Choi Hyun

    2009-05-01

    Full Text Available Abstract Background 3,3'-Diindolylmethane (DIM, an indole derivative produced in the stomach after the consumption of broccoli and other cruciferous vegetables, has been demonstrated to exert anti-cancer effects in both in vivo and in vitro models. We have previously determined that DIM (0 – 30 μmol/L inhibited the growth of HT-29 human colon cancer cells in a concentration-dependent fashion. In this study, we evaluated the effects of DIM on cell cycle progression in HT-29 cells. Methods HT-29 cells were cultured with various concentrations of DIM (0 – 30 μmol/L and the DNA was stained with propidium iodide, followed by flow cytometric analysis. [3H]Thymidine incorporation assays, Western blot analyses, immunoprecipitation and in vitro kinase assays for cyclin-dependent kinase (CDK and cell division cycle (CDC2 were conducted. Results The percentages of cells in the G1 and G2/M phases were dose-dependently increased and the percentages of cells in S phase were reduced within 12 h in DIM-treated cells. DIM also reduced DNA synthesis in a dose-dependent fashion. DIM markedly reduced CDK2 activity and the levels of phosphorylated retinoblastoma proteins (Rb and E2F-1, and also increased the levels of hypophosphorylated Rb. DIM reduced the protein levels of cyclin A, D1, and CDK4. DIM also increased the protein levels of CDK inhibitors, p21CIP1/WAF1 and p27KIPI. In addition, DIM reduced the activity of CDC2 and the levels of CDC25C phosphatase and cyclin B1. Conclusion Here, we have demonstrated that DIM induces G1 and G2/M phase cell cycle arrest in HT-29 cells, and this effect may be mediated by reduced CDK activity.

  4. G1 cell cycle arrest due to the inhibition of erbB family receptor tyrosine kinases does not require the retinoblastoma protein

    International Nuclear Information System (INIS)

    The erbB receptor family (EGFr, erbB-2, erbB-3, and erbB-4) consists of transmembrane glycoproteins that transduce extracellular signals to the nucleus when activated. erbB family members are widely expressed in epithelial, mesenchymal, and neuronal cells and contribute to the proliferation, differentiation, migration, and survival of these cell types. The present study evaluates the effects of erbB family signaling on cell cycle progression and the role that pRB plays in regulating this process. ErbB family RTK activity was inhibited by PD 158780 in the breast epithelial cell line MCF10A. PD 158780 (0.5 μM) inhibited EGF-stimulated and heregulin-stimulated autophosphorylation and caused a G1 cell cycle arrest within 24 h, which correlated with hypophosporylation of pRB. MCF10A cells lacking functional pRB retained the ability to arrest in G1 when treated with PD 158780. Both cell lines showed induction of p27KIP1 protein when treated with PD 158780 and increased association of p27KIP1 with cyclin E-CDK2. Furthermore, CDK2 kinase activity was dramatically inhibited with drug treatment. Changes in other pRB family members were noted with drug treatment, namely a decrease in p107 and an increase in p130. These findings show that the G1 arrest induced through inhibition of erbB family RTK activity does not require functional pRB

  5. Docetaxel enhances apoptosis and G2/M cell cycle arrest by suppressing mitogen-activated protein kinase signaling in human renal clear cell carcinoma.

    Science.gov (United States)

    Han, T D; Shang, D H; Tian, Y

    2016-01-01

    Tremendous efforts have been made in renal cell carcinoma (RCC) patients' research; however, clinical findings in patients have been disappointing. The aims of our study were to identify better or alternative therapeutic methods that can reverse chemotherapy resistance and to enhance sensitivity to docetaxel (DOX)-based chemotherapy drugs. We evaluated the anti-proliferative effect of DOX against RCC cells. DOX was found to suppress proliferation of RCC cells under in vitro and in vivo settings. Flow cytometric analysis revealed that DOX suppressed cell growth by induction of both apoptosis and G2/M cell cycle arrest in a dose-dependent manner. Various patterns of gene expression were observed by cluster analysis. In addition, based on network analysis using the ingenuity pathway analysis software, DOX was found to suppress phosphorylation of extracellular signal-regulated kinase 1/2 and p38, suggesting that the mitogen-activated protein kinase signaling pathway plays a vital role in the anti-proliferative effect of DOX against RCC. PMID:26909952

  6. Effects of maple (Acer) plant part extracts on proliferation, apoptosis and cell cycle arrest of human tumorigenic and non-tumorigenic colon cells.

    Science.gov (United States)

    González-Sarrías, Antonio; Li, Liya; Seeram, Navindra P

    2012-07-01

    Phenolic-enriched extracts of maple sap and syrup, obtained from the sugar and red maple species (Acer saccharum Marsh, A. rubrum L., respectively), are reported to show anticancer effects. Despite traditional medicinal uses of various other parts of these plants by Native Americans, they have not been investigated for anticancer activity. Here leaves, stems/twigs, barks and sapwoods of both maple species were evaluated for antiproliferative effects against human colon tumorigenic (HCT-116, HT-29, Caco-2) and non-tumorigenic (CCD-18Co) cells. Extracts were standardized to total phenolic and ginnalin-A (isolated in our laboratory) levels. Overall, the extracts inhibited the growth of the colon cancer more than normal cells (over two-fold), their activities increased with their ginnalin-A levels, with red > sugar maple extracts. The red maple leaf extract, which contained the highest ginnalin-A content, was the most active extract (IC₅₀  = 35 and 16 µg/mL for extract and ginnalin-A, respectively). The extracts were not cytotoxic nor did they induce apoptosis of the colon cancer cells. However, cell cycle analyses revealed that the antiproliferative effects of the extracts were mediated through cell cycle arrest in the S-phase. The results from the current study suggest that these maple plant part extracts may have potential anticolon cancer effects. PMID:22147441

  7. SKLB70326, a novel small-molecule inhibitor of cell-cycle progression, induces G{sub 0}/G{sub 1} phase arrest and apoptosis in human hepatic carcinoma cells

    Energy Technology Data Exchange (ETDEWEB)

    Han, Yuanyuan; He, Haiyun [State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, West China Medical School, Sichuan University, Chengdu 610041 (China); Peng, Feng [Department of Thoracic Oncology of the Cancer Center and State Key Laboratory of Biotherapy, West China Hospital, West China Medical School, Sichuan University, Chengdu 610041 (China); Liu, Jiyan; Dai, Xiaoyun; Lin, Hongjun; Xu, Youzhi; Zhou, Tian; Mao, Yongqiu; Xie, Gang; Yang, Shengyong; Yu, Luoting; Yang, Li [State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, West China Medical School, Sichuan University, Chengdu 610041 (China); Zhao, Yinglan, E-mail: alancenxb@sina.com [State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, West China Medical School, Sichuan University, Chengdu 610041 (China)

    2012-05-18

    Highlights: Black-Right-Pointing-Pointer SKLB70326 is a novel compound and has activity of anti-HCC. Black-Right-Pointing-Pointer SKLB70326 induces cell cycle arrest and apoptosis in HepG2 cells. Black-Right-Pointing-Pointer SKLB70326 induces G{sub 0}/G{sub 1} phase arrest via inhibiting the activity of CDK2, CDK4 and CDK6. Black-Right-Pointing-Pointer SKLB70326 induces apoptosis through the intrinsic pathway. -- Abstract: We previously reported the potential of a novel small molecule 3-amino-6-(3-methoxyphenyl)thieno[2.3-b]pyridine-2-carboxamide (SKLB70326) as an anticancer agent. In the present study, we investigated the anticancer effects and possible mechanisms of SKLB70326 in vitro. We found that SKLB70326 treatment significantly inhibited human hepatic carcinoma cell proliferation in vitro, and the HepG2 cell line was the most sensitive to its treatment. The inhibition of cell proliferation correlated with G{sub 0}/G{sub 1} phase arrest, which was followed by apoptotic cell death. The SKLB70326-mediated cell-cycle arrest was associated with the downregulation of cyclin-dependent kinase (CDK) 2, CDK4 and CDK6 but not cyclin D1 or cyclin E. The phosphorylation of the retinoblastoma protein (Rb) was also observed. SKLB70326 treatment induced apoptotic cell death via the activation of PARP, caspase-3, caspase-9 and Bax as well as the downregulation of Bcl-2. The expression levels of p53 and p21 were also induced by SKLB70326 treatment. Moreover, SKLB70326 treatment was well tolerated. In conclusion, SKLB70326, a novel cell-cycle inhibitor, notably inhibits HepG2 cell proliferation through the induction of G{sub 0}/G{sub 1} phase arrest and subsequent apoptosis. Its potential as a candidate anticancer agent warrants further investigation.

  8. Zygote arrest 1 gene in pig, cattle and human: evidence of different transcript variants in male and female germ cells

    Directory of Open Access Journals (Sweden)

    Royere Dominique

    2006-03-01

    Full Text Available Abstract Background Zygote arrest 1 (ZAR1 is one of the few known oocyte-specific maternal-effect genes essential for the beginning of embryo development discovered in mice. This gene is evolutionary conserved in vertebrates and ZAR1 protein is characterized by the presence of atypical plant homeobox zing finger domain, suggesting its role in transcription regulation. This work was aimed at the study of this gene, which could be one of the key regulators of successful preimplantation development of domestic animals, in pig and cattle, as compared with human. Methods Screenings of somatic cell hybrid panels and in silico research were performed to characterize ZAR1 chromosome localization and sequences. Rapid amplification of cDNA ends was used to obtain full-length cDNAs. Spatio-temporal mRNA expression patterns were studied using Northern blot, reverse transcription coupled to polymerase chain reaction and in situ hybridization. Results We demonstrated that ZAR1 is a single copy gene, positioned on chromosome 8 in pig and 6 in cattle, and several variants of correspondent cDNA were cloned from oocytes. Sequence analysis of ZAR1 cDNAs evidenced numerous short inverted repeats within the coding sequences and putative Pumilio-binding and embryo-deadenylation elements within the 3'-untranslated regions, indicating the potential regulation ways. We showed that ZAR1 expressed exclusively in oocytes in pig ovary, persisted during first cleavages in embryos developed in vivo and declined sharply in morulae and blastocysts. ZAR1 mRNA was also detected in testis, and, at lower level, in hypothalamus and pituitary in both species. For the first time, ZAR1 was localized in testicular germ cells, notably in round spermatids. In addition, in pig, cattle and human only shorter ZAR1 transcript variants resulting from alternative splicing were found in testis as compared to oocyte. Conclusion Our data suggest that in addition to its role in early embryo

  9. Curcumin induces growth-arrest and apoptosis in association with the inhibition of constitutively active JAK-STAT pathway in T cell leukemia

    International Nuclear Information System (INIS)

    Adult T cell leukemia is an aggressive and frequently fatal malignancy that expressess constitutively activated growth-signaling pathways in association with deregulated growth and resistance to apoptosis. Curcumin (diferuloylmethane) is a naturally occurring yellow pigment, isolated from the rhizomes of the plant Curcuma longa that has traditionally been used in the treatment of injury and inflammation. But the effect and mechanism of action of curcumin on T cell leukemia is not known. To investigate the antitumor activity of curcumin in T cell leukemia, we examined its effect on constitutive phosphorylation of JAK and STAT proteins, proliferation, and apoptosis in HTLV-I-transformed T cell lines. HTLV-I-transformed T cell leukemia lines, MT-2, HuT-102, and SLB-1, express constitutively phosphorylated JAK3, TYK2, STAT3, and STAT5 signaling proteins. In vitro treatment with curcumin induced a dose-dependent decrease in JAK and STAT phosphorylation resulting in the induction of growth-arrest and apoptosis in T cell leukemia. The induction of growth-arrest and apoptosis in association with the blockade of constitutively active JAK-STAT pathway suggests this be a mechanism by which curcumin induces antitumor activity in T cell leukemia

  10. An Ingenol Derived from Euphorbia kansui Induces Hepatocyte Cytotoxicity by Triggering G0/G1 Cell Cycle Arrest and Regulating the Mitochondrial Apoptosis Pathway in Vitro.

    Science.gov (United States)

    Yan, Xiaojing; Zhang, Li; Cao, Yudan; Yao, Weifeng; Tang, Yuping; Ding, Anwei

    2016-01-01

    Natural product lingenol, a purified diterpenoid compound derived from the root of Euphorbia kansui, exerts serious hepatotoxicity; however, the molecular mechanisms remain to be defined. In the present study, cell counting Kit-8 (CCK-8), inverted phase contrast microscope and flow cytometry were used to demonstrate that lingenol significantly inhibited L-O2 cells proliferation, and induced cell cycle arrest and apoptosis. Moreover, the results investigated that lingenol markedly disrupted mitochondrial functions by high content screening (HCS). In addition, the up-regulation of cytochrome c, AIF and Apaf-1 and activation of caspases were found in L-O2 cells detected by Western blotting and ELISA assay, which was required for lingenol activation of cytochrome c-mediated caspase cascades and AIF-mediated DNA damage. Mechanistic investigations revealed that lingenol significantly down-regulated the Bcl-2/Bax ratio and enhanced the reactive oxygen species (ROS) in L-O2 cells. These data collectively indicated that lingenol modulation of ROS and Bcl-2/Bax ratio led to cell cycle arrest and mitochondrial-mediated apoptosis in L-O2 cells in vitro. All of these results will be helpful to reveal the hepatotoxicity mechanism of Euphorbia kansui and to effectively guide safer and better clinical application of this herb. PMID:27338329

  11. An Ingenol Derived from Euphorbia kansui Induces Hepatocyte Cytotoxicity by Triggering G0/G1 Cell Cycle Arrest and Regulating the Mitochondrial Apoptosis Pathway in Vitro

    Directory of Open Access Journals (Sweden)

    Xiaojing Yan

    2016-06-01

    Full Text Available Natural product lingenol, a purified diterpenoid compound derived from the root of Euphorbia kansui, exerts serious hepatotoxicity; however, the molecular mechanisms remain to be defined. In the present study, cell counting Kit-8 (CCK-8, inverted phase contrast microscope and flow cytometry were used to demonstrate that lingenol significantly inhibited L-O2 cells proliferation, and induced cell cycle arrest and apoptosis. Moreover, the results investigated that lingenol markedly disrupted mitochondrial functions by high content screening (HCS. In addition, the up-regulation of cytochrome c, AIF and Apaf-1 and activation of caspases were found in L-O2 cells detected by Western blotting and ELISA assay, which was required for lingenol activation of cytochrome c-mediated caspase cascades and AIF-mediated DNA damage. Mechanistic investigations revealed that lingenol significantly down-regulated the Bcl-2/Bax ratio and enhanced the reactive oxygen species (ROS in L-O2 cells. These data collectively indicated that lingenol modulation of ROS and Bcl-2/Bax ratio led to cell cycle arrest and mitochondrial-mediated apoptosis in L-O2 cells in vitro. All of these results will be helpful to reveal the hepatotoxicity mechanism of Euphorbia kansui and to effectively guide safer and better clinical application of this herb.

  12. 2-Methoxy-4-vinylphenol can induce cell cycle arrest by blocking the hyper-phosphorylation of retinoblastoma protein in benzo[a]pyrene-treated NIH3T3 cells

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Jin Boo [Bioresource Sciences, Andong National University, Andong 760749 (Korea, Republic of); Jeong, Hyung Jin, E-mail: jhj@andong.ac.kr [Bioresource Sciences, Andong National University, Andong 760749 (Korea, Republic of)

    2010-10-01

    Research highlights: {yields} 2M4VP activated the expression of p21 and p15 protein, and down-regulated the expression of cyclin D1 and cyclin E. {yields} 2M4VP inhibited hyper-phosphorylation of Rb protein. {yields} 2M4VP induced cell cycle arrest from G1 to S. {yields} 2M4VP inhibited hyper-proliferation of the cells in BaP-treated cells. {yields} 2M4VP induces growth arrest of BaP-treated cells by blocking hyper-phosphorylation of Rb via regulating the expression of cell cycle-related proteins. -- Abstract: Benzo[a]pyrene (BaP) is an environment carcinogen that can enhance cell proliferation by disturbing the signal transduction pathways in cell cycle regulation. In this study, the effects of 2M4VP on cell proliferation, cell cycle and cell cycle regulatory proteins were studied in BaP-treated NIH 3T3 cells to establish the molecular mechanisms of 2M4VP as anti-proliferative agents. 2M4VP exerted a dose-dependent inhibitory effect on cell growth correlated with a G1 arrest. Analysis of G1 cell cycle regulators expression revealed 2M4VP increased expression of CDK inhibitor, p21Waf1/Cip1 and p15 INK4b, decreased expression of cyclin D1 and cyclin E, and inhibited kinase activities of CDK4 and CDK2. However, 2M4VP did not affect the expression of CDK4 and CDK2. Also, 2M4VP inhibited the hyper-phosphorylation of Rb induced by BaP. Our results suggest that 2M4VP induce growth arrest of BaP-treated NIH 3T3 cells by blocking the hyper-phosphorylation of Rb via regulating the expression of cell cycle-related proteins.

  13. RNAi-mediated knockdown of catalase causes cell cycle arrest in SL-1 cells and results in low survival rate of Spodoptera litura (Fabricius).

    Science.gov (United States)

    Zhao, Haiming; Yi, Xin; Hu, Zhen; Hu, Meiying; Chen, Shaohua; Muhammad, Rizwan-ul-Haq; Dong, Xiaolin; Gong, Liang

    2013-01-01

    Deregulated reactive oxygen species (ROS) production can lead to the disruption of structural and functional integrity of cells as a consequence of reactive interaction between ROS and various biological components. Catalase (CAT) is a common enzyme existing in nearly all organisms exposed to oxygen, which decomposes harmful hydrogen peroxide, into water and oxygen. In this study, the full length sequence that encodes CAT-like protein from Spodoptera litura named siltCAT (GenBank accession number: JQ_663444) was cloned and characterized. Amino acid sequence alignment showed siltCAT shared relatively high conservation with other insect, especially the conserved residues which defined heme and NADPH orientation. Expression pattern analysis showed that siltCAT mRNA was mainly expressed in the fat body, midgut, cuticle and malpighian tube, and as well as over last instar larvae, pupa and adult stages. RNA interference was used to silence CAT gene in SL-1 cells and the fourth-instar stage of S. litura larvae respectively. Our results provided evidence that CAT knockdown induced ROS generation, cell cycle arrest and apoptosis in SL-1 cells. It also confirmed the decrease in survival rate because of increased ROS production in experimental groups injected with double-stranded RNA of CAT (dsCAT). This study implied that ROS scavenging by CAT is important for S. litura survival. PMID:23555693

  14. ETME, a novel β-elemene derivative, synergizes with arsenic trioxide in inducing apoptosis and cell cycle arrest in hepatocarcinoma cells via a p53-dependent pathway

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    Zhiying Yu

    2014-12-01

    Full Text Available Arsenic trioxide (ATO has been identified as an effective treatment for acute promyelocytic leukemia (APL but is much less effective against solid tumors such as hepatocellular carcinoma (HCC. In the search for ways to enhance its therapeutic efficacy against solid tumors, we have examined its use in combination with a novel derivative of β-elemene, N-(β-elemene-13-yltryptophan methyl ester (ETME. Here we report the effects of the combination on cell viability, apoptosis, the cell cycle and mitochondria membrane potential (MMP in HCC SMMC-7721 cells. We found that the two compounds acted synergistically to enhance antiproliferative activity and apoptosis. The combination also decreased the MMP, down-regulated Bcl-2 and pro-proteins of the caspase family, and up-regulated Bax and BID, all of which were reversed by the p53 inhibitor, pifithrin-α. In addition, the combination induced cell cycle arrest at the G2/M phase and reduced tumor volume and weight in an xenograft model of nude mice. Overall, the results suggest that ETME in combination with ATO may be useful in the treatment of HCC patients particularly those unresponsive to ATO alone.

  15. Resistance to bleomycin in cancer cell lines is characterized by prolonged doubling time, reduced DNA damage and evasion of G2/M arrest and apoptosis.

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    Qi Wang

    Full Text Available BACKGROUND: To establish, characterize and elucidate potential mechanisms of acquired bleomycin (BLM resistance using human cancer cell lines. Seven BLM-resistant cell lines were established by exposure to escalating BLM concentrations over a period of 16-24 months. IC50 values and cell doubling times were quantified using a real time cytotoxicity assay. COMET and γ-H2AX assays, cell cycle analysis, and apoptosis assessment further investigated the mechanisms of BLM resistance in these cell lines. RESULTS: Compared with parental cell lines, real time cytotoxicity assays revealed 7 to 49 fold increases in IC50 and a mean doubling time increase of 147 % (range 64 %-352% in BLM-resistant sub-clones (p<0.05 for both. Higher maintenance BLM concentrations were associated with higher IC50 and increased doubling times (p<0.05. Significantly reduced DNA damage (COMET and γ-H2AX assays, G2/M arrest, and apoptosis (p<0.05 for each set of comparison following high-dose acute BLM exposure was observed in resistant sub-clones, compared with their BLM-sensitive parental counterparts. Three weeks of BLM-free culturing resulted in a partial return to BLM sensitivity in 3/7 BLM-resistant sub-clones (p<0.05. CONCLUSION: Bleomycin resistance may be associated with reduced DNA damage after bleomycin exposure, resulting in reduced G2/M arrest, and reduced apoptosis.

  16. Cell division arrest by gamma-irradiation in photoautotrophic suspension culture of Euphorbia characias: maintenance of photosynthetic capacity and overaccumulation of sucrose

    International Nuclear Information System (INIS)

    Gamma-irradiation (250 Gy) applied to photoautotrophic cell suspensions of Euphorbia characias L. in the exponential growth phase led to the arrest of cell division and to a subsequent overaccumulation of sucrose and dry matter. From the fourth day of culture, the chlorophyll content and gross photosynthesis were not depressed by gamma-treatment nor by sugar accumulation. In both cultures, no difference was observed between oxygen uptake in the light at CO2 saturating concentration and in the dark, suggesting that no change in energy-dissipative reactions took place after irradiation. A slight increase in oxygen uptake in both light and dark was observed in irradiated cells during the first four days. However, in the absence of limiting factors, the photosynthetic capacities of the dividing and irradiated non-dividing photoautotrophic cells were identical but higher than that of the non-dividing cells in the stationary growth phase. This suggests that gamma-irradiation arrests cell division by a mechanism different to that occurring in stationary-phase cultures. This may be of value in investigating the metabolism of secondary products. (author)

  17. Connexin32 inhibits gastric carcinogenesis through cell cycle arrest and altered expression of p21Cip1 and p27Kip1

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    Hyang Jee

    2013-01-01

    Full Text Available Gap junctions and their structural proteins, connexins (Cxs, havebeen implicated in carcinogenesis. To explore the involvement ofCx32 in gastric carcinogenesis, immunochemical analysis of Cx32and proliferation marker Ki67 using tissue-microarrayed humangastric cancer and normal tissues was performed. In addition, afterCx32 overexpression in the human gastric cancer cell line AGS,cell proliferation, cell cycle analyses, and p21Cip1 and p27Kip1expression levels were examined by bromodeoxyuridine assay,flow cytometry, real-time RT-PCR, and western blotting.Immunohistochemical study noted a strong inverse correlationbetween Cx32 and Ki67 expression pattern as well as theirlocation. In vitro, overexpression of Cx32 in AGS cells inhibitedcell proliferation significantly. G1 arrest, up-regulation of cellcycle-regulatory proteins p21Cip1 and p27Kip1 was also found atboth mRNA and protein levels. Taken together, Cx32 plays someroles in gastric cancer development by inhibiting gastric cancercell proliferation through cell cycle arrest and cell cycle regulatoryproteins. [BMB Reports 2013; 46(1: 25-30

  18. Platelet-derived growth factor stimulation of [3H]-glucosamine incorporation in density-arrested BALB/c-3T3 cells

    International Nuclear Information System (INIS)

    G0/G1 traverse in density-arrested BALB/c-3T3 cells is controlled by multiple serum-derived growth factors. Platelet-derived growth factor (PDGF) initiates a proliferative response, whereas factors present in plasma facilitate progression through G0/G1. In the absence of competence formation, progression factors are unable to stimulate cell cycle traverse. The authors have identified the stimulation of a biochemical process specific to competence formation in BALB/c-3T3 cells. PDGF treated BALB/c-3T3 cells incorporated 5-10 fold more [3H]-glucosamine (GlcN) into acid-insoluble material as compared to platelet-poor plasma (PPP) treated cultures. Increased GlcN incorporation occurred in density-arrested BALB/c-3T3 cells in response to treatment with other competence factors, fibroblast growth factor, and Ca3 (PO4)2 and was not due to cell-cycle traverse. Stimulation of [3H]-GlcN incorporation by PDGF was time dependent, and increased incorporation of [3H]-GlcN into protein required de novo protein synthesis. Several mechanisms through which PDGF could increase GlcN incorporation into cellular material were examined. Results of these studies suggest an increase in the cellular capacity to glycosylate proteins is a response to or a part of competence formation

  19. Lentivirus-mediated knockdown of TSP50 suppresses the growth of non-small cell lung cancer cells via G0/G1 phase arrest.

    Science.gov (United States)

    Qiao, Wen-Liang; Hu, Hai-Yang; Shi, Bo-Wen; Zang, Li-Juan; Jin, Wei; Lin, Qiang

    2016-06-01

    Non-small cell lung cancer (NSCLC) as the most frequently diagnosed lethal cancer remains the major cause of overall cancer-related death worldwide. Testes-specific protease 50 (TSP50) has been proved as a critical biomarker in various cancers, and we previously reported that TSP50 protein expression is overexpressed in clinical resected NSCLC tumor tissues and related to poor prognosis in NSCLC patients. Hence, the present study was designed to further investigate the potential oncogenesis mechanism of TSP50 in NSCLC cells. Real-time quantitative PCR, immunohistochemical assay and western blot analysis were used to analyze the TSP50 mRNA and protein expression in 20 NSCLC cases, and TSP50 expression was observed to have high levels in the NSCLC specimens and paired metastatic lymph node tissues when compared to the levels in corresponding normal lung tissues and normal lymph nodes. In the experiments in NSCLC cell lines, lentiviral short hairpin RNA (shRNA) delivery system was applied to knock down TSP50 in 95D cells, and the following investigations revealed that downregulation of TSP50 expression markedly reduced cell proliferation, colony formation and migration ability in vitro. Furthermore, the inhibition of TSP50 induced G0/G1-phase arrest and decreased expression levels of cell cycle relative markers CDK4, CDK6, and CyclinD1 and increased expression of p21 and p53 in 95D cells. In conclusion, this study indicates that TSP50 plays a significant role in NSCLC cell proliferation and may act as a novel oncogene in the development and progression of NSCLC, offering a potential cancer therapeutic target for the treatment of NSCLC. PMID:27109614

  20. Annonacin, a mono-tetrahydrofuran acetogenin, arrests cancer cells at the G1 phase and causes cytotoxicity in a Bax- and caspase-3-related pathway.

    Science.gov (United States)

    Yuan, Shyng-Shiou F; Chang, Hsueh-Ling; Chen, Hsiao-Wen; Yeh, Yao-Tsung; Kao, Ying-Hsien; Lin, Kuei-Hsiang; Wu, Yang-Chang; Su, Jinu-Huang

    2003-05-01

    Annonaceous acetogenins are a group of potential anti-neoplastic agents isolated from Annonaceae plants. In this study, we purified annonacin, a cytotoxic mono-tetrahydrofuran acetogenin, from the seeds of Annona reticulata and analyzed its biological effects. Herein, we have shown that annonacin caused significant cell death in various cancer cell lines. T24 bladder cancer cells at the S phase were more vulnerable to the cytotoxicity of annonacin. Furthermore, annonacin activated p21 in a p53-independent manner and arrested T24 cells at the G1 phase. It also induced Bax expression, enhanced caspase-3 activity, and caused apoptotic cell death in T24 cells. In summary, these results suggest that annonacin is potentially a promising anti-cancer compound. PMID:12697268

  1. Jaridonin-induced G2/M phase arrest in human esophageal cancer cells is caused by reactive oxygen species-dependent Cdc2-tyr15 phosphorylation via ATM–Chk1/2–Cdc25C pathway

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Yong-Cheng [Clinical Pharmacology Laboratory, Henan Province People' s Hospital, No. 7, Wei Wu Road, Zhengzhou, Henan (China); Su, Nan [Department of Quality Detection and Management, Henan University of Animal Husbandry and Economy, Zhengzhou, Henan (China); Shi, Xiao-Jing; Zhao, Wen; Ke, Yu [School of Pharmaceutical Sciences, Zhengzhou University, No. 100, Science Avenue, Zhengzhou, Henan (China); Zi, Xiaolin [Department of Urology, University of California, Irvine, Orange, CA (United States); Department of Pharmacology, University of California, Irvine, Orange, CA (United States); Department of Pharmaceutical Sciences, University of California, Irvine, Orange, CA (United States); Zhao, Ning-Min; Qin, Yu-Hua; Zhao, Hong-Wei [Clinical Pharmacology Laboratory, Henan Province People' s Hospital, No. 7, Wei Wu Road, Zhengzhou, Henan (China); Liu, Hong-Min, E-mail: liuhm@zzu.edu.cn [School of Pharmaceutical Sciences, Zhengzhou University, No. 100, Science Avenue, Zhengzhou, Henan (China)

    2015-01-15

    Jaridonin, a novel diterpenoid from Isodon rubescens, has been shown previously to inhibit proliferation of esophageal squamous cancer cells (ESCC) through G2/M phase cell cycle arrest. However, the involved mechanism is not fully understood. In this study, we found that the cell cycle arrest by Jaridonin was associated with the increased expression of phosphorylation of ATM at Ser1981 and Cdc2 at Tyr15. Jaridonin also resulted in enhanced phosphorylation of Cdc25C via the activation of checkpoint kinases Chk1 and Chk2, as well as in increased phospho-H2A.X (Ser139), which is known to be phosphorylated by ATM in response to DNA damage. Furthermore, Jaridonin-mediated alterations in cell cycle arrest were significantly attenuated in the presence of NAC, implicating the involvement of ROS in Jaridonin's effects. On the other hand, addition of ATM inhibitors reversed Jaridonin-related activation of ATM and Chk1/2 as well as phosphorylation of Cdc25C, Cdc2 and H2A.X and G2/M phase arrest. In conclusion, these findings identified that Jaridonin-induced cell cycle arrest in human esophageal cancer cells is associated with ROS-mediated activation of ATM–Chk1/2–Cdc25C pathway. - Highlights: • Jaridonin induced G2/M phase arrest through induction of redox imbalance. • Jaridonin increased the level of ROS through depleting glutathione in cell. • ATM–Chk1/2–Cdc25C were involved in Jaridonin-induced cell cycle arrest. • Jaridonin selectively inhibited cancer cell viability and cell cycle progression.

  2. Jaridonin-induced G2/M phase arrest in human esophageal cancer cells is caused by reactive oxygen species-dependent Cdc2-tyr15 phosphorylation via ATM–Chk1/2–Cdc25C pathway

    International Nuclear Information System (INIS)

    Jaridonin, a novel diterpenoid from Isodon rubescens, has been shown previously to inhibit proliferation of esophageal squamous cancer cells (ESCC) through G2/M phase cell cycle arrest. However, the involved mechanism is not fully understood. In this study, we found that the cell cycle arrest by Jaridonin was associated with the increased expression of phosphorylation of ATM at Ser1981 and Cdc2 at Tyr15. Jaridonin also resulted in enhanced phosphorylation of Cdc25C via the activation of checkpoint kinases Chk1 and Chk2, as well as in increased phospho-H2A.X (Ser139), which is known to be phosphorylated by ATM in response to DNA damage. Furthermore, Jaridonin-mediated alterations in cell cycle arrest were significantly attenuated in the presence of NAC, implicating the involvement of ROS in Jaridonin's effects. On the other hand, addition of ATM inhibitors reversed Jaridonin-related activation of ATM and Chk1/2 as well as phosphorylation of Cdc25C, Cdc2 and H2A.X and G2/M phase arrest. In conclusion, these findings identified that Jaridonin-induced cell cycle arrest in human esophageal cancer cells is associated with ROS-mediated activation of ATM–Chk1/2–Cdc25C pathway. - Highlights: • Jaridonin induced G2/M phase arrest through induction of redox imbalance. • Jaridonin increased the level of ROS through depleting glutathione in cell. • ATM–Chk1/2–Cdc25C were involved in Jaridonin-induced cell cycle arrest. • Jaridonin selectively inhibited cancer cell viability and cell cycle progression

  3. Depletion of intrinsic expression of Interleukin-8 in prostate cancer cells causes cell cycle arrest, spontaneous apoptosis and increases the efficacy of chemotherapeutic drugs

    Directory of Open Access Journals (Sweden)

    Lokeshwar Bal L

    2009-07-01

    Full Text Available Abstract Background The progression of all cancers is characterized by increased-cell proliferation and decreased-apoptosis. The androgen-independent prostate cancer (AIPC is the terminal stage of the disease. Many chemokines and cytokines are suspects to cause this increased tumor cell survival that ultimately leads to resistance to therapy and demise of the host. The AIPC cells, but not androgen-responsive cells, constitutively express abundant amount of the pro-inflammatory chemokine, Interleukin-8 (IL-8. The mechanism of IL-8 mediated survival and therapeutic resistance in AIPC cells is unclear at present. The purpose of this report is to show the pervasive role of IL-8 in malignant progression of androgen-independent prostate cancer (AIPC and to provide a potential new therapeutic avenue, using RNA interference. Results The functional consequence of IL-8 depletion in AIPC cells was investigated by RNA interference in two IL-8 secreting AIPC cell lines, PC-3 and DU145. The non-IL-8 secreting LNCaP and LAPC-4 cells served as controls. Cells were transfected with RISC-free siRNA (control or validated-pool of IL-8 siRNA. Transfection with 50 nM IL-8 siRNA caused >95% depletion of IL-8 mRNA and >92% decrease in IL-8 protein. This reduction in IL-8 led to cell cycle arrest at G1/S boundary and decreases in cell cycle-regulated proteins: Cyclin D1 and Cyclin B1 (both decreased >50% and inhibition of ERK1/2 activity by >50%. Further, the spontaneous apoptosis was increased by >43% in IL-8 depleted cells, evidenced by increases in caspase-9 activation and cleaved-PARP. IL-8 depletion caused significant decreases in anti-apoptotic proteins, BCL-2, BCL-xL due to decrease in both mRNA and post-translational stability, and increased levels of pro-apoptotic BAX and BAD proteins. More significantly, depletion of intracellular IL-8 increased the cytotoxic activity of multiple chemotherapeutic drugs. Specifically, the cytotoxicity of Docetaxel

  4. Combination of Potassium Pentagamavunon-0 and Doxorubicin Induces Apoptosis and Cell Cycle Arrest and Inhibits Metastasis in Breast Cancer Cells.

    Science.gov (United States)

    Putri, Herwandhani; Jenie, Riris Istighfari; Handayani, Sri; Kastian, Ria Fajarwati; Meiyanto, Edy

    2016-01-01

    A salt compound of a curcumin analogue, potassium pentagamavunon-0 (K PGV-0) has been synthesized to improve solubility of pentagamavunon-0 which has been proven to have anti-proliferative effects on several cancer cells. The purpose of this study was to investigate cytotoxic activity and metastasis inhibition by K PGV- 0 alone and in combination with achemotherapeutic agent, doxorubicin (dox), in breast cancer cells. Based on MTT assay analysis, K PGV-0 showed cytotoxic activity in T47D and 4T1 cell lines with IC50 values of 94.9 μM and 49.0±0.2 μM, respectively. In general, K PGV-0+dox demonstrated synergistic effects and decreased cell viability up to 84.7% in T47D cells and 62.6% in 4T1 cells. Cell cycle modulation and apoptosis induction were examined by flow cytometry. K PGV-0 and K PGV-0+dox caused cell accumulation in G2/M phase and apoptosis induction. Regarding cancer metastasis, while K PGV-0 alone did not show any inhibition of 4T1 cell migration, K PGV-0+dox exerted inhibition. K PGV-0 and its combination with dox inhibited the activity of MMP-9 which has a pivotal role in extracellular matrix degradation. These results show that a combination of K PGV-0 and doxorubicin inhibits cancer cell growth through cell cycling, apoptosis induction, and inhibition of cell migration and MMP-9 activity. Therefore, K PGV-0 may have potential for development as a co-chemotherapeutic agent. PMID:27268651

  5. Anaphase-promoting complex/cyclosome protein Cdc27 is a target for curcumin-induced cell cycle arrest and apoptosis

    Directory of Open Access Journals (Sweden)

    Lee Seung Joon

    2012-01-01

    Full Text Available Abstract Background Curcumin (diferuloylmethane, the yellow pigment in the Asian spice turmeric, is a hydrophobic polyphenol from the rhizome of Curcuma longa. Because of its chemopreventive and chemotherapeutic potential with no discernable side effects, it has become one of the major natural agents being developed for cancer therapy. Accumulating evidence suggests that curcumin induces cell death through activation of apoptotic pathways and inhibition of cell growth and proliferation. The mitotic checkpoint, or spindle assembly checkpoint (SAC, is the major cell cycle control mechanism to delay the onset of anaphase during mitosis. One of the key regulators of the SAC is the anaphase promoting complex/cyclosome (APC/C which ubiquitinates cyclin B and securin and targets them for proteolysis. Because APC/C not only ensures cell cycle arrest upon spindle disruption but also promotes cell death in response to prolonged mitotic arrest, it has become an attractive drug target in cancer therapy. Methods Cell cycle profiles were determined in control and curcumin-treated medulloblastoma and various other cancer cell lines. Pull-down assays were used to confirm curcumin binding. APC/C activity was determined using an in vitro APC activity assay. Results We identified Cdc27/APC3, a component of the APC/C, as a novel molecular target of curcumin and showed that curcumin binds to and crosslinks Cdc27 to affect APC/C function. We further provide evidence that curcumin preferably induces apoptosis in cells expressing phosphorylated Cdc27 usually found in highly proliferating cells. Conclusions We report that curcumin directly targets the SAC to induce apoptosis preferably in cells with high levels of phosphorylated Cdc27. Our studies provide a possible molecular mechanism why curcumin induces apoptosis preferentially in cancer cells and suggest that phosphorylation of Cdc27 could be used as a biomarker to predict the therapeutic response of cancer cells to

  6. Anaphase-promoting complex/cyclosome protein Cdc27 is a target for curcumin-induced cell cycle arrest and apoptosis

    International Nuclear Information System (INIS)

    Curcumin (diferuloylmethane), the yellow pigment in the Asian spice turmeric, is a hydrophobic polyphenol from the rhizome of Curcuma longa. Because of its chemopreventive and chemotherapeutic potential with no discernable side effects, it has become one of the major natural agents being developed for cancer therapy. Accumulating evidence suggests that curcumin induces cell death through activation of apoptotic pathways and inhibition of cell growth and proliferation. The mitotic checkpoint, or spindle assembly checkpoint (SAC), is the major cell cycle control mechanism to delay the onset of anaphase during mitosis. One of the key regulators of the SAC is the anaphase promoting complex/cyclosome (APC/C) which ubiquitinates cyclin B and securin and targets them for proteolysis. Because APC/C not only ensures cell cycle arrest upon spindle disruption but also promotes cell death in response to prolonged mitotic arrest, it has become an attractive drug target in cancer therapy. Cell cycle profiles were determined in control and curcumin-treated medulloblastoma and various other cancer cell lines. Pull-down assays were used to confirm curcumin binding. APC/C activity was determined using an in vitro APC activity assay. We identified Cdc27/APC3, a component of the APC/C, as a novel molecular target of curcumin and showed that curcumin binds to and crosslinks Cdc27 to affect APC/C function. We further provide evidence that curcumin preferably induces apoptosis in cells expressing phosphorylated Cdc27 usually found in highly proliferating cells. We report that curcumin directly targets the SAC to induce apoptosis preferably in cells with high levels of phosphorylated Cdc27. Our studies provide a possible molecular mechanism why curcumin induces apoptosis preferentially in cancer cells and suggest that phosphorylation of Cdc27 could be used as a biomarker to predict the therapeutic response of cancer cells to curcumin

  7. Gene expression profiling analysis reveals arsenic-induced cell cycle arrest and apoptosis in p53-proficient and p53-deficient cells through differential gene pathways

    International Nuclear Information System (INIS)

    Arsenic (As) is a well-known environmental toxicant and carcinogen as well as an effective chemotherapeutic agent. The underlying mechanism of this dual capability, however, is not fully understood. Tumor suppressor gene p53, a pivotal cell cycle checkpoint signaling protein, has been hypothesized to play a possible role in mediating As-induced toxicity and therapeutic efficiency. In this study, we found that arsenite (As3+) induced apoptosis and cell cycle arrest in a dose-dependent manner in both p53+/+ and p53-/- mouse embryonic fibroblasts (MEFs). There was, however, a distinction between genotypes in the apoptotic response, with a more prominent induction of caspase-3 in the p53-/- cells than in the p53+/+ cells. To examine this difference further, a systems-based genomic analysis was conducted comparing the critical molecular mechanisms between the p53 genotypes in response to As3+. A significant alteration in the Nrf2-mediated oxidative stress response pathway was found in both genotypes. In p53+/+ MEFs, As3+ induced p53-dependent gene expression alterations in DNA damage and cell cycle regulation genes. However, in the p53-/- MEFs, As3+ induced a significant up-regulation of pro-apoptotic genes (Noxa) and down-regulation of genes in immune modulation. Our findings demonstrate that As-induced cell death occurs through a p53-independent pathway in p53 deficient cells while apoptosis induction occurs through p53-dependent pathway in normal tissue. This difference in the mechanism of apoptotic responses between the genotypes provides important information regarding the apparent dichotomy of arsenic's dual mechanisms, and potentially leads to further advancement of its utility as a chemotherapeutic agent

  8. Dendrobium candidum inhibits MCF-7 cells proliferation by inducing cell cycle arrest at G2/M phase and regulating key biomarkers

    Directory of Open Access Journals (Sweden)

    Sun J

    2015-12-01

    <0.05. The general apoptosis biomarker, Bcl-2, was significantly decreased and the Bax was significantly increased compared to the control group (P<0.05. In contrast to that in MCF-7, D. candidum does not affect cell proliferation at any concentration and any time points in normal breast epithelial cells, MCF10A cells. Conclusion: D. candidum could decrease the cell viability of MCF-7 cells by inducing cell cycle arrest at the G2/M phase and regulating the key biomarkers in breast cancer cells. Keywords: breast cancer, D. candidum, proliferation, biomarker, inhibition

  9. Morphological alterations and G0/G1 cell cycle arrest induced by curcumin in human SK-MEL-37 melanoma cells

    Directory of Open Access Journals (Sweden)

    Marcella Lemos Brettas Carneiro

    2010-04-01

    Full Text Available The aim of this work was to study the effect of curcumin on cell cycle in the human SK-MEL-37 melanoma cell line. In addition, morphological and structural analyses were also performed. Flow cytometric analysis showed a G0/G1 arrest at 5 µM after 24 h exposure and a concentration-dependent increase in the proportion of sub-G0 hypodiploid cells. Typical apoptotic events were also observed by the fluorescence microscopy, transmission and scanning electronic microscopy. Loss of mitochondrial membrane potential was not detected. Results suggested that curcumin could arrest human melanoma cells at G0/G1 phase and induce a mitochondrial-independent apoptotic pathway.O melanoma é um tipo agressivo de câncer cujo tratamento culmina com o estabelecimento de resistência aos quimioterápicos empregados. Portanto, é importante o desenvolvimento de novos agentes farmacológicos que sejam menos tóxicos e que não provoquem quimiorresistência. As inúmeras propriedades terapêuticas da curcumina vêm sendo confirmadas através de estudos sobre o seu mecanismo de ação em células cultivadas. No presente estudo, empregamos células de melanoma humano da linhagem SK-MEL-37, que desenvolveram resistência in vitro à doxorubicina e cisplatina, drogas normalmente utilizadas na clínica. Investigamos o efeito da curcumina sobre o ciclo celular através de citometria de fluxo. Além disso, análises morfológicas e estruturais também foram realizadas. Os resultados demonstraram que o tratamento com uma concentração de 5 ?M de curcumina provocou uma parada na subfase G0/G1. Além disso, observou-se um aumento dose-dependente na proporção de células hipodiplóides em sub-G0. Eventos apoptóticos típicos foram observados por microscopia de fluorescência, microscopia eletrônica de transmissão e microscopia eletrônica de varredura. Não foi detectada alteração no potencial de membrana mitocondrial. Os resultados indicam que futuros estudos poder

  10. G protein-coupled receptor 30 ligand G-1 increases aryl hydrocarbon receptor signalling by inhibition of tubulin assembly and cell cycle arrest in human MCF-7 cells.

    Science.gov (United States)

    Tarnow, Patrick; Tralau, Tewes; Luch, Andreas

    2016-08-01

    Regulatory crosstalk between the aryl hydrocarbon receptor (AHR) and oestrogen receptor α (ERα) is well established. Apart from the nuclear receptors ERα and ERβ, oestrogen signalling further involves an unrelated G protein-coupled receptor termed GPR30. In order to investigate potential regulatory crosstalk, this study investigated the influence of G-1 as one of the few GPR30-specific ligands on the AHR regulon in MCF-7 cells. As a well-characterised model system, these human mammary carcinoma cells co-express all three receptors (AHR, ERα and GPR30) and are thus ideally suited to study corresponding regulatory pathway interactions on transcript level. Indeed, treatment with micromolar concentrations of the GPR30-specific agonist G-1 resulted in up-regulation of AHR as well as the transcripts for cytochromes P450 1A1 and 1B1, two well-known targets of the AHR regulon. While this was partly attributable to G-1-mediated inhibition of tubulin assembly and subsequent cell cycle arrest in the G2/M phase, the effects nevertheless required functional AHR. However, G-1-induced up-regulation of CYP 1A1 was not mediated by GPR30, as G15 antagonist treatment as well as a knockdown of GPR30 and AHR failed to inhibit this effect. PMID:26475489

  11. Sarsaparilla (Smilax Glabra Rhizome) Extract Inhibits Cancer Cell Growth by S Phase Arrest, Apoptosis, and Autophagy via Redox-Dependent ERK1/2 Pathway.

    Science.gov (United States)

    She, Tiantian; Qu, Like; Wang, Lixin; Yang, Xingxin; Xu, Shuo; Feng, Junnan; Gao, Yujing; Zhao, Chuanke; Han, Yong; Cai, Shaoqing; Shou, Chengchao

    2015-05-01

    Cancer is still the major cause of death across the world. Regular approaches cannot effectively solve the emerging problems, including drug/radiation resistance, side effects, and therapeutic ineffectiveness. Natural dietary supplements have shown effectiveness in the prevention and treatment of cancer. Sarsaparilla (Smilax Glabra Rhizome) has growth-inhibitory effects on several cancer cell lines in vitro and in vivo, with little toxicity on normal cells. However, the mechanism underlying its function remains elusive. In the present study, we examined the anticancer activity of the supernatant of the water-soluble extract (SW) from sarsaparilla. Liquid chromatography/mass spectrometry-ion trap-time-of-flight (LC/MS-IT-TOF) analysis identified flavonoids, alkaloids, and phenylpropanoids as the major bioactive components of SW. SW was shown to markedly inhibit the growth of a broad spectrum of cancer cell lines in the in vitro and in vivo assays. S phase arrest, autophagy, or/and apoptosis were partly responsible for SW-induced growth inhibition. Results of microarray analysis and validation by quantitative RT-PCR indicated the involvement of oxidative stress and the MAPK1 pathway in SW-treated cells. We further found that SW destroyed intracellular-reduced glutathione/oxidized glutathione (GSH/GSSG) balance, and supplement with N-acetylcysteine (NAC) or glutathione (GSH) significantly antagonized SW-induced S phase arrest, apoptosis, and autophagy. In addition, SW-induced GSH/GSSG imbalance activated the ERK1/2 pathway, which contributed to SW-induced S phase arrest, apoptosis, autophagy, and resultant growth-inhibitory effect. Together, our results provide a molecular basis for sarsaparilla as an anticancer agent. PMID:25732255

  12. E2F1 enhances 8-chloro-adenosine-induced G2/M arrest and apoptosis in A549 and H1299 lung cancer cells.

    Science.gov (United States)

    Duan, Hong-Ying; Cao, Ji-Xiang; Qi, Jun-Juan; Wu, Guo-Sheng; Li, Shu-Yan; An, Guo-Shun; Jia, Hong-Ti; Cai, Wang-Wei; Ni, Ju-Hua

    2012-03-01

    The E2F1 transcription factor is a well known regulator of cell proliferation and apoptosis, but its role in response to DNA damage is less clear. 8-Chloro-adenosine (8-Cl-Ado), a nucleoside analog, can inhibit proliferation in a variety of human tumor cells. However, it is still elusive how the agent acts on tumors. Here we show that A549 and H1299 cells formed DNA double-strand breaks after 8-Cl-Ado exposure, accompanied by E2F1 upregulation at protein level. Overexpressed wild-type (E2F1-wt) colocalized with double-strand break marker γ-H2AX and promoted G2/M arrest in 8-Cl-Ado-exposed A549 and H1299, while expressed S31A mutant of E2F1 (E2F1-mu) significantly reduced ability to accumulate at sites of DNA damage and G2/M arrest, suggesting that E2F1 is required for activating G2/M checkpoint pathway upon DNA damage. Transfection of either E2F1-wt or E2F1-mu plasmid promoted apoptosis in 8-Cl-Ado-exposed cells, indicating that 8-Cl-Ado may induce apoptosis in E2F1-dependent and E2F1-independent ways. These findings demonstrate that E2F1 plays a crucial role in 8-Cl-Ado-induced G2/M arrest but is dispensable for 8-Cl-Ado-induced apoptosis. These data also suggest that the mechanism of 8-Cl-Ado action is complicated. PMID:22803943

  13. Semi-purified extracts of Commelina benghalensis (Commelinaceae) induce apoptosis and cell cycle arrest in Jurkat-T cells

    OpenAIRE

    Lebogo, Kgomotso Welheminah; Mokgotho, Matlou Phineas; Bagla, Victor Patrick; Matsebatlela, Thabe Moses; Mbazima, Vusi; Shai, Leshwene Jeremiah; Mampuru, Leseilane

    2014-01-01

    Background Commelina benghalensis (CB) is a small plant whose fleshy stems are used in South Africa to treat skin conditions (e.g., cancerous skin outgrowths). This study was aimed at evaluating the effect of sub-fractions of acetone extracts of CB stems on growth-associated molecular events of apoptosis and cell division cycle of Jurkat-T (JT) cells. Methods Acetone extract of CB stems were subfractioned into n-hexane (F1) and dichloromethane (F2) fractions. After treatment of JT cells with ...

  14. Overexpression of GSTA2 protects against cell cycle arrest and apoptosis induced by the DNA inter-strand crosslinking nitrogen mustard, mechlorethamine.

    Science.gov (United States)

    Xie, Jingping; Shults, Keith; Flye, Leanne; Jiang, Fen; Head, David R; Briggs, Robert C

    2005-05-15

    The effectiveness of bifunctional alkylating nitrogen mustard compounds in chemotherapy is related to their ability to form DNA inter-strand crosslinks. Patients exposed to DNA inter-strand crosslinking (ICL) agents subsequently experience an elevated incidence of myelodysplastic syndromes (MDS) and MDS related acute myeloid leukemia. Fanconi's anemia (FA) patients are deficient in the repair of crosslink DNA damage and they experience a high incidence of MDS. These observations indicate that hematopoietic cells are specific target for the transforming effects of DNA crosslinking damage. Changes in transcript levels were characterized in human hematopoietic cells occurring in response to the nitrogen mustard, mechlorethamine (HN2), but not in response to monofunctional analogs. Only modest changes in a few gene transcripts were detected in HL60 cells exposed to levels of HN2 tittered to maximal dose that caused growth suppression with minimal cell death and allowed eventual resumption of normal cell growth. Under conditions of transient growth suppression, a subset of glutathione-S-transferase (GST) isoenzyme genes was consistently upregulated three to fourfold by HN2, but not by monofunctional analogs. Subsequent efforts to confirm the changes detected by microarray analyses revealed an unexpected dependence on treatment conditions. The GST alpha class A2 subfamily member transcripts were upregulated 24 h after a 1 h exposure to HN2 that caused an extensive, but transient block in late S/G2 cell cycle phase, but were minimally altered with continuous exposure. The 1-h exposure to HN2 caused a transient late S/G2 cell cycle arrest in both the HL-60 cell line and the Colo 320HSR human colon cancer cell line. Overexpression of GSTA2 by transient transfection protected Colo 320HSR cells against both cycle arrest and apoptosis following exposure to HN2. Overexpression of GSTA2 in Colo 320HSR cells induced after exposure to HN2 did not alter cycle arrest or apoptosis

  15. G2/M Cell Cycle Arrest and Tumor Selective Apoptosis of Acute Leukemia Cells by a Promising Benzophenone Thiosemicarbazone Compound

    OpenAIRE

    Cabrera, Maia; Gomez, Natalia; Remes Lenicov, Federico; Echeverría, Emiliana; Shayo, Carina; Moglioni, Albertina; Fernández, Natalia; Davio, Carlos

    2015-01-01

    Anti-mitotic therapies have been considered a hallmark in strategies against abnormally proliferating cells. Focusing on the extensively studied family of thiosemicarbazone (TSC) compounds, we have previously identified 4,4’-dimethoxybenzophenone thiosemicarbazone (T44Bf) as a promising pharmacological compound in a panel of human leukemia cell lines (HL60, U937, KG1a and Jurkat). Present findings indicate that T44Bf-mediated antiproliferative effects are associated with a reversible chronic ...

  16. MeHg Developing Exposure Causes DNA Double-Strand Breaks and Elicits Cell Cycle Arrest in Spinal Cord Cells

    Directory of Open Access Journals (Sweden)

    Fabiana F. Ferreira

    2015-01-01

    Full Text Available The neurotoxicity caused by methylmercury (MeHg is well documented; however, the developmental neurotoxicity in spinal cord is still not fully understood. Here we investigated whether MeHg affects the spinal cord layers development. Chicken embryos at E3 were treated in ovo with 0.1 μg MeHg/50 μL saline solution and analyzed at E10. Thus, we performed immunostaining using anti-γ-H2A.X to recognize DNA double-strand breaks and antiphosphohistone H3, anti-p21, and anti-cyclin E to identify cells in proliferation and cell cycle proteins. Also, to identify neuronal cells, we used anti-NeuN and anti-βIII-tubulin antibodies. After the MeHg treatment, we observed the increase on γ-H2A.X in response to DNA damage. MeHg caused a decrease in the proliferating cells and in the thickness of spinal cord layers. Moreover, we verified that MeHg induced an increase in the number of p21-positive cells but did not change the cyclin E-positive cells. A significantly high number of TUNEL-positive cells indicating DNA fragmentation were observed in MeHg-treated embryos. Regarding the neuronal differentiation, MeHg induced a decrease in NeuN expression and did not change the expression of βIII-tubulin. These results showed that in ovo MeHg exposure alters spinal cord development by disturbing the cell proliferation and death, also interfering in early neuronal differentiation.

  17. MeHg Developing Exposure Causes DNA Double-Strand Breaks and Elicits Cell Cycle Arrest in Spinal Cord Cells

    Science.gov (United States)

    Ferreira, Fabiana F.; Ammar, Dib; Bourckhardt, Gilian F.; Kobus-Bianchini, Karoline; Müller, Yara M. R.; Nazari, Evelise M.

    2015-01-01

    The neurotoxicity caused by methylmercury (MeHg) is well documented; however, the developmental neurotoxicity in spinal cord is still not fully understood. Here we investigated whether MeHg affects the spinal cord layers development. Chicken embryos at E3 were treated in ovo with 0.1 μg MeHg/50 μL saline solution and analyzed at E10. Thus, we performed immunostaining using anti-γ-H2A.X to recognize DNA double-strand breaks and antiphosphohistone H3, anti-p21, and anti-cyclin E to identify cells in proliferation and cell cycle proteins. Also, to identify neuronal cells, we used anti-NeuN and anti-βIII-tubulin antibodies. After the MeHg treatment, we observed the increase on γ-H2A.X in response to DNA damage. MeHg caused a decrease in the proliferating cells and in the thickness of spinal cord layers. Moreover, we verified that MeHg induced an increase in the number of p21-positive cells but did not change the cyclin E-positive cells. A significantly high number of TUNEL-positive cells indicating DNA fragmentation were observed in MeHg-treated embryos. Regarding the neuronal differentiation, MeHg induced a decrease in NeuN expression and did not change the expression of βIII-tubulin. These results showed that in ovo MeHg exposure alters spinal cord development by disturbing the cell proliferation and death, also interfering in early neuronal differentiation. PMID:26793240

  18. Growth arrest and apoptosis via caspase activation of dioscoreanone in human non-small-cell lung cancer A549 cells

    OpenAIRE

    Hansakul, Pintusorn; Aree, Kalaya; Tanuchit, Sermkiat; Itharat, Arunporn

    2014-01-01

    Background Dioscoreanone (DN) isolated from Dioscorea membranacea Pierre has been reported to exert potent cytotoxic effects against particular types of cancer. The present study was carried out to investigate the cytotoxicity of DN against a panel of different human lung cancer cell lines. The study further examined the underlying mechanisms of its anticancer activity in the human lung adenocarcinoma cell line A549. Methods Antiproliferative effects of DN were determined by SRB and CFSE assa...

  19. Action of caffeine on x-irradiated HeLa cells. III. enhancement of x-ray-induced killing during G2 arrest

    International Nuclear Information System (INIS)

    The ability of caffeine to enhance the expression of potentially lethal x-ray damage in HeLa S3 cells was examined as a function of the age of the cells in the generation cycle. Synchronous populations were irradiated at different times after mitotic collection and treated for various intervals with 1 mM caffeiene, which causes negligible killing of unirradiated cells. The response was thereby determined as a function of cell age at both the time of irradiation and the time of exposure to caffeine. The amount of cell killing depends strongly on when in the cycle caffeine is present and only weakly on when the cells are irradiated. If cells are irradiated in early G1, caffeine treatment enhances killing for 2 to 3 hr. No additional enhancement is observed until 16 to 17 hr postcollection, corresponding to G2; here they enter a second period of much greater sensitivity. Similarly, fluorodeoxyuridine resynchronized cells irradiated during S and treated with caffeine suffer no enhanced killing until they pass into this sensitive phase in G2, approximately 7 hr after release from the fluorodeoxyuridine block. The sensitive period appears to coincide with G2 arrest. The rate and extent of killing during this period are dependent upon the x-ray dose and the caffeine concentration. In the absence of caffeine, cells irradiated in G1 lose sensitivity to caffeine in about 9 hr; they do so faster in G2. It is concluded that the potentially lethal x-ray damage expressed on treatment with caffeine is retained for many hours in the presence of caffeine and is maximally manifested by G2-arrested cells

  20. Theaflavin-3, 3'-digallate induces apoptosis and G2 cell cycle arrest through the Akt/MDM2/p53 pathway in cisplatin-resistant ovarian cancer A2780/CP70 cells.

    Science.gov (United States)

    Tu, Youying; Kim, Eunhye; Gao, Ying; Rankin, Gary O; Li, Bo; Chen, Yi Charlie

    2016-06-01

    Ovarian cancer is the most lethal gynecological cancer among women worldwide. Adverse side effects and acquired resistance to conventional platinum based chemotherapy are major impediments in ovarian cancer treatment, and drive the development of more selective anticancer drugs that target cancer-specific defects. In this study, theaflavin-3, 3'-digallate (TF3), the major theaflavin monomer in black tea, exhibited a potent growth inhibitory effect on the cisplatin-resistant ovarian cancer A2780/CP70 cells (IC50, 23.81 µM), and was less cytotoxic to a normal ovarian IOSE‑364 cells (IC50, 59.58 µM) than to the cancer cells. Flow cytometry analysis indicated that TF3 induced preferential apoptosis and G2 cell cycle arrest in A2780/CP70 cells with respect to IOSE‑364 cells. TF3 induced apoptosis through both the intrinsic and extrinsic apoptotic pathways, and caused G2 cell cycle arrest via cyclin B1 in A2780/CP70 cells. The p53 protein played an important role in TF3-induced apoptosis and G2 cell cycle arrest. TF3 might upregulate the p53 expression via the Akt/MDM2 pathway. Our findings help elucidate the mechanisms by which TF3 may contribute to the prevention and treatment of platinum-resistant ovarian cancer. PMID:27082635

  1. Polypeptide Fraction from Arca subcrenata Induces Apoptosis and G2/M Phase Arrest in HeLa Cells via ROS-Mediated MAPKs Pathways

    Directory of Open Access Journals (Sweden)

    Xianjing Hu

    2015-01-01

    Full Text Available Arca subcrenata is documented in the literature of marine Traditional Chinese Medicine. Polypeptide fraction from A. subcrenata, coded as P2, was demonstrated to possess significant antitumor activity in our previous study. However, the underlying mechanism remains undefined. The present study was carried out to investigate the underlying antitumor mechanism of P2 in human cervical cancer HeLa cells by MTT, FCM, LSCM, and western blot assays. The results revealed that P2 significantly induced apoptosis of HeLa cells in a concentration- and time-dependent manner. High level of ROS was provoked by P2, which was in turn responsible for induction of apoptosis through activation of intrinsic mitochondrial pathway and JNK1/2, p38 MAPK pathways, as well as inhibition of ERK1/2 pathway, as evidenced by the abrogation of P2’s effect on HeLa cells preincubated with the ROS scavenger NAC. P2 also was observed to display significant effect on G2/M phase arrest by downregulating the expression of cyclin B1/cdc2 complex and upregulating the expression of p21. These findings demonstrate that P2 induces apoptosis and G2/M phase arrest in HeLa cells through ROS-mediated MAPKs pathways, suggesting that P2 would be worth investigating as a promising agent within the scope of marine drugs for treatment of cervical cancer.

  2. The depletion of Interleukin-8 causes cell cycle arrest and increases the efficacy of docetaxel in breast cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Shao, Nan [Breast Disease Center, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou (China); Chen, Liu-Hua [Department of Minimally Invasive Surgery Center, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou (China); Ye, Run-Yi [Breast Disease Center, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou (China); Lin, Ying, E-mail: frostlin@hotmail.com [Breast Disease Center, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou (China); Wang, Shen-Ming, E-mail: shenmingwang@hotmail.com [Breast Disease Center, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou (China)

    2013-02-15

    Highlights: ► IL-8 depletion affects cell cycle distribution. ► Intrinsic IL-8 mediates breast cancer cell migration and invasion. ► IL-8 siRNA down regulates key factors that control survival and metastatic pathway. ► IL-8 depletion reduces integrin β3 expression. ► IL-8 depletion increases the chemosensitivity to docetaxel. -- Abstract: IL-8 is a multi-functional pro-inflammatory chemokine, which is highly expressed in cancers, such as ER-negative breast cancer. The present study demonstrates the pervasive role of IL-8 in the malignant progression of ER-negative breast cancer. IL-8 siRNA inhibited proliferation and delayed the G1 to S cell cycle progression in MDA-MB-231 and BT549 cells. IL-8 silencing resulted in the upregulation of the CDK inhibitor p27, the downregulation of cyclin D1, and the reduction of phosphorylated-Akt and NF-κB activities. IL-8 depletion also increased the chemosensitivity to docetaxel. These results indicate a role for IL-8 in promoting tumor cell survival and resistance to docetaxel and highlight the potential therapeutic significance of IL-8 depletion in ER-negative breast cancer patients.

  3. Aspafilioside B induces G2/M cell cycle arrest and apoptosis by up-regulating H-Ras and N-Ras via ERK and p38 MAPK signaling pathways in human hepatoma HepG2 cells.

    Science.gov (United States)

    Liu, Wei; Ning, Rui; Chen, Rui-Ni; Huang, Xue-Feng; Dai, Qin-Sheng; Hu, Jin-Hua; Wang, Yu-Wen; Wu, Li-Li; Xiong, Jing; Hu, Gang; Guo, Qing-Long; Yang, Jian; Wang, Hao

    2016-05-01

    We recently establish that aspafilioside B, a steroidal saponin extracted from Asparagus filicinus, is an active cytotoxic component. However, its antitumor activity is till unknown. In this study, the anticancer effect of aspafilioside B against HCC cells and the underlying mechanisms were investigated. Our results showed that aspafilioside B inhibited the growth and proliferation of HCC cell lines. Further study revealed that aspafilioside B could significantly induce G2 phase cell cycle arrest and apoptosis, accompanying the accumulation of reactive oxygen species (ROS), but blocking ROS generation with N-acetyl-l-cysteine (NAC) could not prevent G2/M arrest and apoptosis. Additionally, treatment with aspafilioside B induced phosphorylation of extracellular signal-regulated kinase (ERK) and p38 MAP kinase. Moreover, both ERK inhibitor PD98059 and p38 inhibitor SB203580 almost abolished the G2/M phase arrest and apoptosis induced by aspafilioside B, and reversed the expression of cell cycle- and apoptosis-related proteins. We also found that aspafilioside B treatment increased both Ras and Raf activation, and transfection of cells with H-Ras and N-Ras shRNA almost attenuated aspafilioside B-induced G2 phase arrest and apoptosis as well as the ERK and p38 activation. Finally, in vivo, aspafilioside B suppressed tumor growth in mouse xenograft models, and the mechanism was the same as in vitro study. Collectively, these findings indicated that aspafilioside B may up-regulate H-Ras and N-Ras, causing c-Raf phosphorylation, and lead to ERK and p38 activation, which consequently induced the G2 phase arrest and apoptosis. This study provides the evidence that aspafilioside B is a promising therapeutic agent against HCC. PMID:25683703

  4. The role of the RACK1 ortholog Cpc2p in modulating pheromone-induced cell cycle arrest in fission yeast.

    Directory of Open Access Journals (Sweden)

    Magdalena Mos

    Full Text Available The detection and amplification of extracellular signals requires the involvement of multiple protein components. In mammalian cells the receptor of activated C kinase (RACK1 is an important scaffolding protein for signal transduction networks. Further, it also performs a critical function in regulating the cell cycle by modulating the G1/S transition. Many eukaryotic cells express RACK1 orthologs, with one example being Cpc2p in the fission yeast Schizosaccharomyces pombe. In contrast to RACK1, Cpc2p has been described to positively regulate, at the ribosomal level, cells entry into M phase. In addition, Cpc2p controls the stress response pathways through an interaction with Msa2p, and sexual development by modulating Ran1p/Pat1p. Here we describe investigations into the role, which Cpc2p performs in controlling the G protein-mediated mating response pathway. Despite structural similarity to Gβ-like subunits, Cpc2p appears not to function at the G protein level. However, upon pheromone stimulation, cells overexpressing Cpc2p display substantial cell morphology defects, disorientation of septum formation and a significantly protracted G1 arrest. Cpc2p has the potential to function at multiple positions within the pheromone response pathway. We provide a mechanistic interpretation of this novel data by linking Cpc2p function, during the mating response, with its previous described interactions with Ran1p/Pat1p. We suggest that overexpressing Cpc2p prolongs the stimulated state of pheromone-induced cells by increasing ste11 gene expression. These data indicate that Cpc2p regulates the pheromone-induced cell cycle arrest in fission yeast by delaying cells entry into S phase.

  5. Vitamin D Arrests Thyroid Carcinoma Cell Growth and Induces p27 Dephosphorylation and Accumulation through PTEN/Akt-Dependent and -Independent Pathways

    OpenAIRE

    Wei LIU; Asa, Sylvia L.; Fantus, I. George; Walfish, Paul G.; Ezzat, Shereen

    2002-01-01

    We investigated the effects of 1,25-dihydroxycholecalciferol vitamin D3 (VD) and its noncalciomimetic analog EB1089 on thyroid carcinoma cell growth. VD and EB1089 exhibited anti-proliferative effects in a dose-dependent manner as determined by [3H]thymidine incorporation and MIB-1 immunolabeling. VD or EB1089 resulted in similar G1-phase arrest. Neither apoptosis nor differentiation was affected. VD and EB1089 induced increased nuclear protein expression of the cyclin-dependent kinase inhibi...

  6. Genetic inactivation of Cdk7 leads to cell cycle arrest and induces premature aging due to adult stem cell exhaustion

    OpenAIRE

    Ganuza, Miguel; Sáiz-Ladera, Cristina; Cañamero, Marta; Gómez, Gonzalo; Schneider, Ralph; Blasco, María A.; Pisano, David; Paramio, Jesús M.; Santamaría, David; Barbacid, Mariano

    2012-01-01

    Employing a conditionally inactive gene trap allele, Cdk7's function in regulating cellular proliferation by Cdk1/2-phosphorylation is convincingly dissected from alternative notions on CTD-phosphorylation of RNA Pol II. Premature aging phenotypes caused by stem cell depletion lend the necessary functional support.

  7. Cyclin G2 is a centrosome-associated nucleocytoplasmic shuttling protein that influences microtubule stability and induces a p53-dependent cell cycle arrest

    International Nuclear Information System (INIS)

    Cyclin G2 is an atypical cyclin that associates with active protein phosphatase 2A. Cyclin G2 gene expression correlates with cell cycle inhibition; it is significantly upregulated in response to DNA damage and diverse growth inhibitory stimuli, but repressed by mitogenic signals. Ectopic expression of cyclin G2 promotes cell cycle arrest, cyclin dependent kinase 2 inhibition and the formation of aberrant nuclei [Bennin, D. A., Don, A. S., Brake, T., McKenzie, J. L., Rosenbaum, H., Ortiz, L., DePaoli-Roach, A. A., and Horne, M. C. (2002). Cyclin G2 associates with protein phosphatase 2A catalytic and regulatory B' subunits in active complexes and induces nuclear aberrations and a G1/S-phase cell cycle arrest. J Biol Chem 277, 27449-67]. Here we report that endogenous cyclin G2 copurifies with centrosomes and microtubules (MT) and that ectopic G2 expression alters microtubule stability. We find exogenous and endogenous cyclin G2 present at microtubule organizing centers (MTOCs) where it colocalizes with centrosomal markers in a variety of cell lines. We previously reported that cyclin G2 forms complexes with active protein phosphatase 2A (PP2A) and colocalizes with PP2A in a detergent-resistant compartment. We now show that cyclin G2 and PP2A colocalize at MTOCs in transfected cells and that the endogenous proteins copurify with isolated centrosomes. Displacement of the endogenous centrosomal scaffolding protein AKAP450 that anchors PP2A at the centrosome resulted in the depletion of centrosomal cyclin G2. We find that ectopic expression of cyclin G2 induces microtubule bundling and resistance to depolymerization, inhibition of polymer regrowth from MTOCs and a p53-dependent cell cycle arrest. Furthermore, we determined that a 100 amino acid carboxy-terminal region of cyclin G2 is sufficient to both direct GFP localization to centrosomes and induce cell cycle inhibition. Colocalization of endogenous cyclin G2 with only one of two GFP-centrin-tagged centrioles, the

  8. Baicalein induces G1 arrest in oral cancer cells by enhancing the degradation of cyclin D1 and activating AhR to decrease Rb phosphorylation

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Ya-Hsin, E-mail: yhcheng@mail.cmu.edu.tw [Department of Physiology, School of Medicine, China Medical University, Taichung 40402, Taiwan, ROC (China); Li, Lih-Ann; Lin, Pinpin; Cheng, Li-Chuan [Division of Environmental Health and Occupational Medicine, National Health Research Institutes, Zhunan, Miaoli 35053, Taiwan, ROC (China); Hung, Chein-Hui [Graduate Institute of Clinical Medicine Sciences, Chang Gung University, Puizi City, Chiayi 613, Taiwan, ROC (China); Chang, Nai Wen [Department of Biochemistry, School of Medicine, China Medical University, Taichung, Taiwan, ROC (China); Lin, Chingju [Department of Physiology, School of Medicine, China Medical University, Taichung 40402, Taiwan, ROC (China)

    2012-09-15

    Baicalein is a flavonoid, known to have anti-inflammatory and anti-cancer effects. As an aryl hydrocarbon receptor (AhR) ligand, baicalein at high concentrations blocks AhR-mediated dioxin toxicity. Because AhR had been reported to play a role in regulating the cell cycle, we suspected that the anti-cancer effect of baicalein is associated with AhR. This study investigated the molecular mechanism involved in the anti-cancer effect of baicalein in oral cancer cells HSC-3, including whether such effect would be AhR-mediated. Results revealed that baicalein inhibited cell proliferation and increased AhR activity in a dose-dependent manner. Cell cycle was arrested at the G1 phase and the expression of CDK4, cyclin D1, and phosphorylated retinoblastoma (pRb) was decreased. When the AhR was suppressed by siRNA, the reduction of pRb was partially reversed, accompanied by a decrease of cell population at G1 phase and an increase at S phase, while the reduction of cyclin D1 and CDK4 did not change. This finding suggests that the baicalein activation of AhR is indeed associated with the reduction of pRb, but is independent of the reduction of cyclin D1 and CDK4. When cells were pre-treated with LiCl, the inhibitor of GSK-3β, the decrease of cyclin D1 was blocked and the reduction of pRb was recovered. The data indicates that in HSC-3 the reduction of pRb is both mediated by baicalein through activation of AhR and facilitation of cyclin D1 degradation, which causes cell cycle arrest at the G1 phase, and results in the inhibition of cell proliferation. -- Highlights: ► Baicalein causes the G1 phase arrest by decreasing Rb phosphorylation. ► Baicalein modulates AhR-mediated cell proliferation. ► Both AhR activation and cyclin D1 degradation results in hypophosphorylation of Rb. ► Baicalein facilitates cyclin D1 degradation by signalling the GSK-3β pathway.

  9. Baicalein induces G1 arrest in oral cancer cells by enhancing the degradation of cyclin D1 and activating AhR to decrease Rb phosphorylation

    International Nuclear Information System (INIS)

    Baicalein is a flavonoid, known to have anti-inflammatory and anti-cancer effects. As an aryl hydrocarbon receptor (AhR) ligand, baicalein at high concentrations blocks AhR-mediated dioxin toxicity. Because AhR had been reported to play a role in regulating the cell cycle, we suspected that the anti-cancer effect of baicalein is associated with AhR. This study investigated the molecular mechanism involved in the anti-cancer effect of baicalein in oral cancer cells HSC-3, including whether such effect would be AhR-mediated. Results revealed that baicalein inhibited cell proliferation and increased AhR activity in a dose-dependent manner. Cell cycle was arrested at the G1 phase and the expression of CDK4, cyclin D1, and phosphorylated retinoblastoma (pRb) was decreased. When the AhR was suppressed by siRNA, the reduction of pRb was partially reversed, accompanied by a decrease of cell population at G1 phase and an increase at S phase, while the reduction of cyclin D1 and CDK4 did not change. This finding suggests that the baicalein activation of AhR is indeed associated with the reduction of pRb, but is independent of the reduction of cyclin D1 and CDK4. When cells were pre-treated with LiCl, the inhibitor of GSK-3β, the decrease of cyclin D1 was blocked and the reduction of pRb was recovered. The data indicates that in HSC-3 the reduction of pRb is both mediated by baicalein through activation of AhR and facilitation of cyclin D1 degradation, which causes cell cycle arrest at the G1 phase, and results in the inhibition of cell proliferation. -- Highlights: ► Baicalein causes the G1 phase arrest by decreasing Rb phosphorylation. ► Baicalein modulates AhR-mediated cell proliferation. ► Both AhR activation and cyclin D1 degradation results in hypophosphorylation of Rb. ► Baicalein facilitates cyclin D1 degradation by signalling the GSK-3β pathway.

  10. Exposure to radon daughters in workplaces

    International Nuclear Information System (INIS)

    The paper focuses on the exposure to natural radiation at places of work, in the United Kingdom. Sources of natural radiation include: cosmic rays, radiation from the earth, internal body radioactivity, and radon daughters. These sources are described, along with exposure standards for radon daughters. Factors leading to the variability and unpredictability of radon daughter concentrations in work places, and recent studies of radon concentrations in UK buildings, are both discussed. Methods for measuring radon and its daughters, and measures to reduce radon concentrations in buildings, are also outlined. (U.K.)

  11. Mushroom extract increases p53 expression and causes cell cycle arrest and apoptosis in a breast cancer cell line

    OpenAIRE

    Vaz, Josiana A.; Tavares, Catarina; Almeida, Gabriela M.; Martins, Anabela; Ferreira, Isabel C. F. R.; Vasconcelos, M. Helena

    2012-01-01

    Mushrooms are part of the sexual life cycle of particular fungi with specific metabolic pathways, and therefore may contain a largely unexploited source of powerful new pharmaceutical products with potential antitumor properties [1,2]. Furthermore, they may have potential as functional foods. Suillus collinitus is an edible mushroom found in European pine forests. The aim of this work was to study the cytotoxic potential of extracts from this mushroom in various cancer cell lines....

  12. Platinum (IV) complex LA-12 induces cell cycle arrest and phase specific apoptosis in colon carcinoma cells HCT116

    Czech Academy of Sciences Publication Activity Database

    Blanářová, Olga; Jelínková, I.; Jendželovský, R.; Souček, Karel; Hofmanová, Jiřina; Sova, P.; Kozubík, Alois

    Geneva: Elsevier, 2008. s. 89. ISSN 1359-6349. [20th EORTC-NCI-AACR, Symposium on Molecular Targets and Cancer Therapeutics. 21.10.2008-24.10.2008, Geneva] R&D Projects: GA AV ČR(CZ) 1QS500040507; GA ČR(CZ) GA301/07/1557 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : platinum complex * cell cycle * apoptosis Subject RIV: BO - Biophysics

  13. Euphol arrests breast cancer cells at the G1 phase through the modulation of cyclin D1, p21 and p27 expression.

    Science.gov (United States)

    Wang, Lin; Wang, Guiying; Yang, Dandan; Guo, Xudong; Xu, Yanxin; Feng, Bo; Kang, Jiuhong

    2013-10-01

    Euphorbia tirucalli is a long‑established treatment for a wide variety of cancers. However, the mechanism of its anticancer effect is yet to be elucidated. In the present study, we examined the anticancer effect of euphol, a tetracyclic triterpene alcohol isolated from the sap of Euphorbia tirucalli, in T47D human breast cancer cells. Following the treatment of cells with different doses of euphol for 24, 48 and 72 h, the cell proliferation, cell cycle, and mRNA and protein levels of cell cycle regulatory molecules were analyzed, respectively. Treatment of the cells with euphol resulted in decreased cell viability, which was accompanied by an accumulation of cells in the G1 phase. Further studies demonstrated that euphol treatment downregulated cyclin D1 expression and the hypophosphorylation of Rb. Furthermore, this effect was correlated with the downregulation of cyclin‑dependent kinase 2 (CDK2) expression and the upregulation of the CDK inhibitors p21 and p27. Reduced expression levels of cyclin A and B1 were also observed, corresponding to the decreased distribution of cells in the S and G2/M phases, respectively. These findings indicated that euphol is an active agent in Euphorbia tirucalli that exerts anticancer activity by arresting the cell cycle of cancer cells. PMID:23969579

  14. Silencing of RTKN2 by siRNA suppresses proliferation, and induces G1 arrest and apoptosis in human bladder cancer cells.

    Science.gov (United States)

    Liao, Yi-Xiang; Zeng, Jin-Min; Zhou, Jia-Jie; Yang, Guang-Hua; Ding, Kun; Zhang, Xian-Jue

    2016-06-01

    Human bladder cancer is the most common urological malignancy in China. One of the causes of carcinogenesis in the cancer may be gene mutation. Therefore, the present study investigated the expression levels of Rhotekin 2 (RTKN2), a Rho effector protein, in human bladder cancer tissues and cell lines, and examined the effect of RTKN2 on the proliferation, cell cycle, apoptosis and invasion of human bladder cancer cell lines. The mRNA expression levels of RTKN2 in 30 human bladder cancer tissue samples were significantly higher, compared with those in 30 normal human bladder tissue samples. The protein expression levels of RTKN2 was markedly higher in T24 and 5637 cells, compared with those in four other human bladder cancer cell lines. The silencing of RTKN2 by small interfering (si)RNA inhibited cell proliferation and arrested cell cycle at the G1 phase, via reducing the expression levels of the MCM10, CDK2, CDC24A and CDC6 cell cycle‑associated proteins in the T24 and 5637 cells. Furthermore, RTKN2 knockdown in the cells led to cell apoptosis and the suppression of invasion. These results suggested that RTKN2 is involved in the carcinogenesis and progression of human bladder cancer, indicating that RTKN2 may be a molecular target in cancer therapy. PMID:27082503

  15. Novel microtubule-targeted agent 6-chloro-4-(methoxyphenyl) coumarin induces G2-M arrest andapoptosis in HeLa cells

    Institute of Scientific and Technical Information of China (English)

    Yi-ming MA; Yu-bo ZHOU; Chuan-ming XIE; Dong-mei CHEN; Jia LI

    2012-01-01

    To identify a novel coumarin analogue with the highest anticancer activity and to further investigate its anticancer mechanisms.Methods:The viability of cancer cells was investigated using the MTT assay.The cell cycle progression was evaluated using both flow cytometric and Western blotting analysis.Microtubule depolymerization was observed with immunocytochemistry in vivo and a tubu-lin depolymerization assay in vitro.Apoptosis was demonstrated using Annexin V/Propidium Iodide (PI) double-staining and sub-G1analysis.Results:Among 36 analogues of coumarin,6-chloro-4-(methoxyphenyl) coumarin showed the best anticancer activity (IC50 value about 200 nmol/L) in HCT116 cells.The compound had a broad spectrum of anticancer activity against 9 cancer cell lines derived from colon cancer,breast cancer,liver cancer,cervical cancer,leukemia,epidermoid cancer with IC5o value of 75 nmol/L-1.57 μmol/L but with low cytotocitity against WI-38 human lung fibroblasts (IC50 value of 12.128 μmol/L).The compound (0.04-10 μmol/L) induced G2-M phase arrest in HeLa cells in a dose-dependent manner,which was reversible after the compound was removed.The compound (10-300 μmol/L) induced the depolymerization of purified porcine tubulin in vitro.Finally,the compound (0.04-2.5 μmol/L) induced apoptosis of HeLa cells in dose- and time-dependent manners.Conclusion:6-Chloro-4-(methoxyphenyl) coumarin is a novel microtubule-targeting agent that induces G2-M arrest and apoptosis in HeLa cells.

  16. Deterrence and arrest ratios.

    Science.gov (United States)

    Carmichael, Stephanie E; Piquero, Alex R

    2006-02-01

    In the limited research on the origins of sanction threat perceptions, researchers have focused on either the effects of actively engaging in crime or the effects of formal sanctioning but rarely on both (i.e., the arrest ratio or the number of arrests relative to the number of crimes committed). This article extends this line of research by using a sample of Colorado inmates and measures arrest ratios and sanction perceptions for eight different crime types. Analyses reveal that the offenders report both significant experiential and arrest ratio effects. Theoretical and policy implications, limitations, and directions for future research are outlined. PMID:16397123

  17. Maple polyphenols, ginnalins A-C, induce S- and G2/M-cell cycle arrest in colon and breast cancer cells mediated by decreasing cyclins A and D1 levels.

    Science.gov (United States)

    González-Sarrías, Antonio; Ma, Hang; Edmonds, Maxwell E; Seeram, Navindra P

    2013-01-15

    Polyphenols are bioactive compounds found in plant foods. Ginnalins A-C are polyphenols present in the sap and other parts of the sugar and red maple species which are used to produce maple syrup. Here we evaluated the antiproliferative effects of ginnalins A-C on colon (HCT-116) and breast (MCF-7) tumourigenic and non-tumourigenic colon (CCD-18Co) cells and investigated whether these effects were mediated through cell cycle arrest and/or apoptosis. Ginnalins A-C were twofold more effective against the tumourigenic than non-tumourigenic cells. Among the polyphenols, ginnalin A (84%, HCT-116; 49%, MCF-7) was more effective than ginnalins B and C (50%, HCT-116; 30%, MCF-7) at 50 μM concentrations. Ginnalin A did not induce apoptosis of the cancer cells but arrested cell cycle (in the S- and G(2)/M-phases) and decreased cyclins A and D1 protein levels. These results suggest that maple polyphenols may have potential cancer chemopreventive effects mediated through cell cycle arrest. PMID:23122108

  18. 4β-Hydroxywithanolide E from Physalis peruviana (golden berry) inhibits growth of human lung cancer cells through DNA damage, apoptosis and G2/M arrest

    International Nuclear Information System (INIS)

    The crude extract of the fruit bearing plant, Physalis peruviana (golden berry), demonstrated anti-hepatoma and anti-inflammatory activities. However, the cellular mechanism involved in this process is still unknown. Herein, we isolated the main pure compound, 4β-Hydroxywithanolide (4βHWE) derived from golden berries, and investigated its antiproliferative effect on a human lung cancer cell line (H1299) using survival, cell cycle, and apoptosis analyses. An alkaline comet-nuclear extract (NE) assay was used to evaluate the DNA damage due to the drug. It was shown that DNA damage was significantly induced by 1, 5, and 10 μg/mL 4βHWE for 2 h in a dose-dependent manner (p < 0.005). A trypan blue exclusion assay showed that the proliferation of cells was inhibited by 4βHWE in both dose- and time-dependent manners (p < 0.05 and 0.001 for 24 and 48 h, respectively). The half maximal inhibitory concentrations (IC50) of 4βHWE in H1299 cells for 24 and 48 h were 0.6 and 0.71 μg/mL, respectively, suggesting it could be a potential therapeutic agent against lung cancer. In a flow cytometric analysis, 4βHWE produced cell cycle perturbation in the form of sub-G1 accumulation and slight arrest at the G2/M phase with 1 μg/mL for 12 and 24 h, respectively. Using flow cytometric and annexin V/propidium iodide immunofluorescence double-staining techniques, these phenomena were proven to be apoptosis and complete G2/M arrest for H1299 cells treated with 5 μg/mL for 24 h. In this study, we demonstrated that golden berry-derived 4βHWE is a potential DNA-damaging and chemotherapeutic agent against lung cancer

  19. Radiation resistance due to high expression of miR-21 and G2/M checkpoint arrest in breast cancer cells

    International Nuclear Information System (INIS)

    There is evidence that the extent of the G2/M arrest following irradiation is correlated with tumour cell survival and hence therapeutic success. We studied the regulation of cellular response to radiation treatment by miR-21-mediated modulation of cell cycle progression in breast cancer cells and analysed miR-21 expression in breast cancer tissue samples with long-term follow up. The miR-21 expression levels were quantified (qRT-PCR) in a panel of 86 cases of invasive breast carcinomas in relation to metastasis free survival. The cellular radiosensitivity of human breast cancer cells after irradiation was determined comparing two cell lines (T47D and MDA-MB-361) by cell proliferation and colony forming assays. The influence of miR-21 overexpression or downregulation on cell cycle progression and G2/M checkpoint arrest after irradiation was assessed by flow cytometric analysis. The expression of miR-21 was transiently increased 8 hours after irradiation in the radioresistant T47D cells and significantly changed with lower extent in radiosensitive MDA-MB-361 cells. Anti-miR-21 treated breast cancer cells failed to exhibit the DNA damage-G2 checkpoint increase after irradiation. Apoptotic activity was significantly enhanced from 7% to 27% in T47D cells and from 18% to 30% in MDA-MB-361 cells 24 hours after 5 Gy irradiation. Additionally, we characterized expression of miR-21 in invasive breast carcinomas. In comparison to non-cancerous adjacent breast tissue, tumours samples had increased miR-21 expression that inversely correlated with the distant metastases-free survival of patients (p = 0.029). Our data indicate that miR-21 expression in breast cancer cells contributes to radiation resistance by compromising cell cycle progression. These data point to the potential of combining radiotherapy with an anti-miR-21 as a potent G2/M check point inhibitor in overcoming radiation resistance of tumours

  20. Radiation resistance due to high expression of miR-21 and G2/M checkpoint arrest in breast cancer cells

    Directory of Open Access Journals (Sweden)

    Anastasov Nataša

    2012-12-01

    Full Text Available Abstract Background There is evidence that the extent of the G2/M arrest following irradiation is correlated with tumour cell survival and hence therapeutic success. We studied the regulation of cellular response to radiation treatment by miR-21-mediated modulation of cell cycle progression in breast cancer cells and analysed miR-21 expression in breast cancer tissue samples with long-term follow up. Methods The miR-21 expression levels were quantified (qRT-PCR in a panel of 86 cases of invasive breast carcinomas in relation to metastasis free survival. The cellular radiosensitivity of human breast cancer cells after irradiation was determined comparing two cell lines (T47D and MDA-MB-361 by cell proliferation and colony forming assays. The influence of miR-21 overexpression or downregulation on cell cycle progression and G2/M checkpoint arrest after irradiation was assessed by flow cytometric analysis. Results The expression of miR-21 was transiently increased 8 hours after irradiation in the radioresistant T47D cells and significantly changed with lower extent in radiosensitive MDA-MB-361 cells. Anti-miR-21 treated breast cancer cells failed to exhibit the DNA damage-G2 checkpoint increase after irradiation. Apoptotic activity was significantly enhanced from 7% to 27% in T47D cells and from 18% to 30% in MDA-MB-361 cells 24 hours after 5 Gy irradiation. Additionally, we characterized expression of miR-21 in invasive breast carcinomas. In comparison to non-cancerous adjacent breast tissue, tumours samples had increased miR-21 expression that inversely correlated with the distant metastases-free survival of patients (p = 0.029. Conclusions Our data indicate that miR-21 expression in breast cancer cells contributes to radiation resistance by compromising cell cycle progression. These data point to the potential of combining radiotherapy with an anti-miR-21 as a potent G2/M check point inhibitor in overcoming radiation resistance of tumours.

  1. Differential biologic effects of CPD and 6-4PP UV-induced DNA damage on the induction of apoptosis and cell-cycle arrest

    Directory of Open Access Journals (Sweden)

    Yasui Akira

    2005-10-01

    Full Text Available Abstract Background UV-induced damage can induce apoptosis or trigger DNA repair mechanisms. Minor DNA damage is thought to halt the cell cycle to allow effective repair, while more severe damage can induce an apoptotic program. Of the two major types of UV-induced DNA lesions, it has been reported that repair of CPD, but not 6-4PP, abrogates mutation. To address whether the two major forms of UV-induced DNA damage, can induce differential biological effects, NER-deficient cells containing either CPD photolyase or 6-4 PP photolyase were exposed to UV and examined for alterations in cell cycle and apoptosis. In addition, pTpT, a molecular mimic of CPD was tested in vitro and in vivo for the ability to induce cell death and cell cycle alterations. Methods NER-deficient XPA cells were stably transfected with CPD-photolyase or 6-4PP photolyase to specifically repair only CPD or only 6-4PP. After 300 J/m2 UVB exposure photoreactivation light (PR, UVA 60 kJ/m2 was provided for photolyase activation and DNA repair. Apoptosis was monitored 24 hours later by flow cytometric analysis of DNA content, using sub-G1 staining to indicate apoptotic cells. To confirm the effects observed with CPD lesions, the molecular mimic of CPD, pTpT, was also tested in vitro and in vivo for its effect on cell cycle and apoptosis. Results The specific repair of 6-4PP lesions after UVB exposure resulted in a dramatic reduction in apoptosis. These findings suggested that 6-4PP lesions may be the primary inducer of UVB-induced apoptosis. Repair of CPD lesions (despite their relative abundance in the UV-damaged cell had little effect on the induction of apoptosis. Supporting these findings, the molecular mimic of CPD, (dinucleotide pTpT could mimic the effects of UVB on cell cycle arrest, but were ineffective to induce apoptosis. Conclusion The primary response of the cell to UV-induced 6-4PP lesions is to trigger an apoptotic program whereas the response of the cell to CPD

  2. N-methylpurine DNA glycosylase inhibits p53-mediated cell cycle arrest and coordinates with p53 to determine sensitivity to alkylating agents

    Institute of Scientific and Technical Information of China (English)

    Shanshan Song; Guichun Xing; Lin Yuan; Jian Wang; Shan Wang; Yuxin Yin; Chunyan Tian; Fuchu He; Lingqiang Zhang

    2012-01-01

    Alkylating agents induce genome-wide base damage,which is repaired mainly by N-methylpurine DNA glycosylase (MPG).An elevated expression of MPG in certain types of tumor cells confers higher sensitivity to alkylation agents because MPG-induced apurinic/apyrimidic (AP) sites trigger more strand breaks.However,the determinant of drug sensitivity or insensitivity still remains unclear.Here,we report that the p53 status coordinates with MPG to play a pivotal role in such process.MPG expression is positive in breast,lung and colon cancers (38.7%,43.4% and 25.3%,respectively) but negative in all adjacent normal tissues.MPG directly binds to the tumor suppressor p53 and represses p53 activity in unstressed cells.The overexpression of MPG reduced,whereas depletion of MPG increased,the expression levels of pro-arrest gene downstream of p53 including p21,14-3-3σ and Gadd45 but not pro-apoptotic ones.The N-terminal region of MPG was specifically required for the interaction with the DNA binding domain of p53.Upon DNA alkylation stress,in p53 wild-type tumor cells,p53 dissociated from MPG and induced cell growth arrest.Then,AP sites were repaired efficiently,which led to insensitivity to alkylating agents.By contrast,in p53-mutated cells,the AP sites were repaired with low efficacy.To our knowledge,this is the first direct evidence to show that a DNA repair enzyme functions as a selective regulator of p53,and these findings provide new insights into the functional linkage between MPG and p53 in cancer therapy.

  3. 4β-Hydroxywithanolide E from Physalis peruviana (golden berry inhibits growth of human lung cancer cells through DNA damage, apoptosis and G2/M arrest

    Directory of Open Access Journals (Sweden)

    Guo Zong-Lun

    2010-02-01

    Full Text Available Abstract Background The crude extract of the fruit bearing plant, Physalis peruviana (golden berry, demonstrated anti-hepatoma and anti-inflammatory activities. However, the cellular mechanism involved in this process is still unknown. Methods Herein, we isolated the main pure compound, 4β-Hydroxywithanolide (4βHWE derived from golden berries, and investigated its antiproliferative effect on a human lung cancer cell line (H1299 using survival, cell cycle, and apoptosis analyses. An alkaline comet-nuclear extract (NE assay was used to evaluate the DNA damage due to the drug. Results It was shown that DNA damage was significantly induced by 1, 5, and 10 μg/mL 4βHWE for 2 h in a dose-dependent manner (p p 50 of 4βHWE in H1299 cells for 24 and 48 h were 0.6 and 0.71 μg/mL, respectively, suggesting it could be a potential therapeutic agent against lung cancer. In a flow cytometric analysis, 4βHWE produced cell cycle perturbation in the form of sub-G1 accumulation and slight arrest at the G2/M phase with 1 μg/mL for 12 and 24 h, respectively. Using flow cytometric and annexin V/propidium iodide immunofluorescence double-staining techniques, these phenomena were proven to be apoptosis and complete G2/M arrest for H1299 cells treated with 5 μg/mL for 24 h. Conclusions In this study, we demonstrated that golden berry-derived 4βHWE is a potential DNA-damaging and chemotherapeutic agent against lung cancer.

  4. Fe{sub 3}O{sub 4} nanoparticle loaded paclitaxel induce multiple myeloma apoptosis by cell cycle arrest and increase cleavage of caspases in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Cuiping [Medical School, Southeast University, Department of Pathogenic Biology and Immunology (China); He, Xiangfeng [Affiliated Tumor Hospital of Nantong University, Department of Medical Oncology (China); Chen, Junsong; Chen, Dengyu; Liu, Yunjing [Medical School, Southeast University, Department of Pathogenic Biology and Immunology (China); Xiong, Fei [Southeast University, School of Biological Science and Medical Engineering (China); Shi, Fangfang [Zhongda Hospital, Southeast University, Department of Oncology (China); Dou, Jun, E-mail: njdoujun@yahoo.com.cn [Medical School, Southeast University, Department of Pathogenic Biology and Immunology (China); Gu, Ning, E-mail: guning@seu.edu.cn [Southeast University, School of Biological Science and Medical Engineering (China)

    2013-08-15

    Multiple myeloma (MM) still remains an incurable disease in spite of extending the patient survival by new therapies. The hypothesis of cancer stem cells (CSCs) states that although chemotherapy kills most tumor cells, it is believed to leave a reservoir of CSCs that allows the tumor cell propagation. The objective of this research was to evaluate the therapeutic effect of new paclitaxel-Fe{sub 3}O{sub 4} nanoparticles (PTX-NPs) with an average size range of 7.17 {+-} 1.31 nm on MM CSCs in vitro. The characteristics of CD138{sup -}CD34{sup -} cells, isolated from human MM RPMI 8226 and NCI-H929 cell lines by the magnetic associated cell sorting method, were identified by the assays of colony formation, cell proliferation, drug resistance, cell migration, and tumorigenicity in non-obese diabetic/severe combined immunodeficiency (NOD/SCID) mice, respectively. Inhibitory effects of PTX-NPs on CD138{sup -}CD34{sup -} cells were evaluated by a variety of assays in vitro. The results showed that the CD138{sup -}CD34{sup -} cells were capable of forming colonies, exhibited high proliferative and migratory ability, possessed a strong drug resistance, and had powerful tumorigenicity in NOD/SCID mice compared to non-CD138{sup -}CD34{sup -} cells. PTX-NPs significantly inhibited CD138{sup -} CD34{sup -} cell viability and invasive ability, and resulted in G0/G1 cell cycle arrest and apoptosis compared with PTX alone. We concluded that the CD138{sup -}CD34{sup -} phenotype cells might be CSCs in RPMI 8226 and NCI-H929 cell lines. PTX-NPs had an obvious inhibitory effect on MM CD138{sup -}CD34{sup -} CSCs. The findings may provide a guideline for PTX-NPs' treatment of MM CSCs in preclinical investigation.

  5. Fe3O4 nanoparticle loaded paclitaxel induce multiple myeloma apoptosis by cell cycle arrest and increase cleavage of caspases in vitro

    International Nuclear Information System (INIS)

    Multiple myeloma (MM) still remains an incurable disease in spite of extending the patient survival by new therapies. The hypothesis of cancer stem cells (CSCs) states that although chemotherapy kills most tumor cells, it is believed to leave a reservoir of CSCs that allows the tumor cell propagation. The objective of this research was to evaluate the therapeutic effect of new paclitaxel-Fe3O4 nanoparticles (PTX-NPs) with an average size range of 7.17 ± 1.31 nm on MM CSCs in vitro. The characteristics of CD138−CD34− cells, isolated from human MM RPMI 8226 and NCI-H929 cell lines by the magnetic associated cell sorting method, were identified by the assays of colony formation, cell proliferation, drug resistance, cell migration, and tumorigenicity in non-obese diabetic/severe combined immunodeficiency (NOD/SCID) mice, respectively. Inhibitory effects of PTX-NPs on CD138−CD34− cells were evaluated by a variety of assays in vitro. The results showed that the CD138−CD34− cells were capable of forming colonies, exhibited high proliferative and migratory ability, possessed a strong drug resistance, and had powerful tumorigenicity in NOD/SCID mice compared to non-CD138−CD34− cells. PTX-NPs significantly inhibited CD138− CD34− cell viability and invasive ability, and resulted in G0/G1 cell cycle arrest and apoptosis compared with PTX alone. We concluded that the CD138−CD34− phenotype cells might be CSCs in RPMI 8226 and NCI-H929 cell lines. PTX-NPs had an obvious inhibitory effect on MM CD138−CD34− CSCs. The findings may provide a guideline for PTX-NPs’ treatment of MM CSCs in preclinical investigation

  6. Exine dehiscing induces rape microspore polarity, which results in different daughter cell fate and fixes the apical–basal axis of the embryo

    OpenAIRE

    Tang, Xingchun; Liu, Yuan; He, Yuqing; Ma, Ligang; Sun, Meng-xiang

    2012-01-01

    The roles of cell polarity and the first asymmetric cell division during early embryogenesis in apical–basal cell fate determination remain unclear. Previously, a novel Brassica napus microspore embryogenesis system was established, by which rape exine-dehisced microspores were induced by physical stress. Unlike traditional microspore culture, cell polarity and subsequent asymmetric division appeared in the exine-dehisced microspore, which finally developed into a typical embryo with a suspen...

  7. N-Methyl-N'-nitro-N-nitrosoguanidine-induced senescence-like growth arrest in colon cancer cells is associated with loss of adenomatous polyposis coli protein, microtubule organization, and telomeric DNA

    Directory of Open Access Journals (Sweden)

    Narayan Satya

    2004-01-01

    Full Text Available Abstract Background Cellular senescence is a state in which mammalian cells enter into an irreversible growth arrest and altered biological functions. The senescence response in mammalian cells can be elicited by DNA-damaging agents. In the present study we report that the DNA-damaging agent N-methyl-N'-nitro-N-nitrosoguanidine (MNNG is able to induce senescence in the HCT-116 colon cancer cell line. Results Cells treated with lower concentrations of MNNG (0–25 microM for 50 h showed a dose-dependent increase in G2/M phase arrest and apoptosis; however, cells treated with higher concentrations of MNNG (50–100 microM showed a senescence-like G0/G1 phase arrest which was confirmed by increased expression of β-galactosidase, a senescence induced marker. The G2/M phase arrest and apoptosis were found to be associated with increased levels of p53 protein, but the senescence-like G0/G1 phase arrest was dissociated with p53 protein levels, since the p53 protein levels decreased in senescence-like arrested cells. We further, determined whether the decreased level of p53 was a transcriptional or a translational phenomenon. The results revealed that the decreased level of p53 protein in senescence-like arrested cells was a transcriptional phenomenon since p53 mRNA levels simultaneously decreased after treatment with higher concentrations of MNNG. We also examined the effect of MNNG treatment on other cell cycle-related proteins such as p21, p27, cyclin B1, Cdc2, c-Myc and max. The expression levels of these proteins were increased in cells treated with lower concentrations of MNNG, which supported the G2/M phase arrest. However, cells treated with higher concentrations of MNNG showed decreased levels of these proteins, and hence, may not play a role in cell cycle arrest. We then examined a possible association of the expression of APC protein and telomeric DNA signals with cellular senescence in MNNG-treated cells. We found that protein and m

  8. Antitumor activity of di-n-butyl-(2,6-difluorobenzohydroxamatotin(IV against human gastric carcinoma SGC-7901 cells via G2/M cell cycle arrest and cell apoptosis.

    Directory of Open Access Journals (Sweden)

    Li Yunlan

    Full Text Available Di-n-butyl-(2,6-difluorobenzohydroxamatoTin(IV (DBDFT, a potential antitumor agent against malignancies, exhibited high activities both in vitro and in vivo. Flow cytometric analysis showed that treatment with DBDFT against Human Gastric Carcinoma (SGC-7901 cells induced a concentration and time-dependent cell accumulation in the G2/M phase of the cell cycle with a parallel depletion of the percentage of cells in G0/G1, the cell apoptosis was observed by characteristic morphological changes and AnnexinV/PI dual-immunofluorescence staining. Fluorescence quantitative FQ- PCR and western blot results showed that G2/M-phase arrest was correlated with up-regulation of cyclin dependent kinase inhibitor p21, Chk2 and CyclinB1, whereas the expressions of other G2/M regulatory check-point protein, Cdc2, and feedback loop protein Cdc25C were obviously down-regulated in a p53-independent manner after the SGC-7901 cells were treated with DBDFT (2.5, 5.0, 7.5 µmol·L(-1 compared with the control. Furthermore, the up-regulation of Bax and down-regulation of Bcl-2 as well as the activation of caspase-3 were observed, which indicated that DBDFT treatment triggered the mitochondrial apoptotic pathway with an increase of Bax/Bcl-2 ratios, resulting in mitochondrial membrane potential loss and caspase-9 activation in DBDFT treated SGC-7901 cells. In summary, the results illustrated the involvement of multiple signaling pathways targeted by DBDFT in mediating G2/M cell cycle arrest and apoptosis in SGC-7901 cells, which suggested that DBDFT might have therapeutic potential against gastric carcinoma as an effective compound.

  9. Glycoprotein 5 of porcine reproductive and respiratory syndrome virus strain SD16 inhibits viral replication and causes G2/M cell cycle arrest, but does not induce cellular apoptosis in Marc-145 cells

    Energy Technology Data Exchange (ETDEWEB)

    Mu, Yang, E-mail: muyang@nwsuaf.edu.cn [Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A& F University, No. 22 Xinong Road, Yangling, Shaanxi 712100 (China); Experimental Station of Veterinary Pharmacology and Veterinary Biotechnology, Ministry of Agriculture of the People' s Republic of China, No. 22 Xinong Road, Yangling, Shaanxi 712100 (China); Li, Liangliang, E-mail: lifeiyang2007@126.com [Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A& F University, No. 22 Xinong Road, Yangling, Shaanxi 712100 (China); Experimental Station of Veterinary Pharmacology and Veterinary Biotechnology, Ministry of Agriculture of the People' s Republic of China, No. 22 Xinong Road, Yangling, Shaanxi 712100 (China); Zhang, Beibei, E-mail: diana851218@163.com [Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A& F University, No. 22 Xinong Road, Yangling, Shaanxi 712100 (China); Experimental Station of Veterinary Pharmacology and Veterinary Biotechnology, Ministry of Agriculture of the People' s Republic of China, No. 22 Xinong Road, Yangling, Shaanxi 712100 (China); Huang, Baicheng, E-mail: hbch228@163.com [Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A& F University, No. 22 Xinong Road, Yangling, Shaanxi 712100 (China); Experimental Station of Veterinary Pharmacology and Veterinary Biotechnology, Ministry of Agriculture of the People' s Republic of China, No. 22 Xinong Road, Yangling, Shaanxi 712100 (China); Gao, Jiming, E-mail: jimingao2006@163.com [Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A& F University, No. 22 Xinong Road, Yangling, Shaanxi 712100 (China); Experimental Station of Veterinary Pharmacology and Veterinary Biotechnology, Ministry of Agriculture of the People' s Republic of China, No. 22 Xinong Road, Yangling, Shaanxi 712100 (China); and others

    2015-10-15

    Cell apoptosis is common after infection with porcine reproductive and respiratory syndrome virus (PRRSV). PRRSV GP5 has been reported to induce cell apoptosis. To further understand the role of GP5 in PRRSV induced cell apoptosis, we established Marc-145 cell lines stably expressing full-length GP5, GP5{sup Δ84-96} (aa 84-96 deletion), and GP5{sup Δ97-119} (aa 97-119 deletion). Cell proliferation, cell cycle progression, cell apoptosis and virus replication in these cell lines were evaluated. Neither truncated nor full-length GP5 induced cell apoptosis in Marc-145 cells. However, GP5{sup Δ97-119}, but not full-length or GP5{sup Δ84-96}, induced a cell cycle arrest at the G2/M phase resulting in a reduction in the growth of Marc-145 cells. Additionally, GP5{sup Δ84-96} inhibited the replication of PRRSV in Marc-145 cells through induction of IFN-β. These findings suggest that PRRSV GP5 is not responsible for inducing cell apoptosis in Marc-145 cells under these experimental conditions; however it has other important roles in virus/host cell biology. - Highlights: • Marc-145 cell lines stable expression PRRSV GP5 or truncated GP5 were constructed. • GP5{sup Δ97-119} expression in Marc-145 cell induced cell cycle arrest at G2/M phase. • Expression of GP5 and truncated GP5 could not induce Marc-145 cells apoptosis. • PRRSV replication in Marc-145-GP5{sup Δ84-96} was significantly inhibited.

  10. Glycoprotein 5 of porcine reproductive and respiratory syndrome virus strain SD16 inhibits viral replication and causes G2/M cell cycle arrest, but does not induce cellular apoptosis in Marc-145 cells

    International Nuclear Information System (INIS)

    Cell apoptosis is common after infection with porcine reproductive and respiratory syndrome virus (PRRSV). PRRSV GP5 has been reported to induce cell apoptosis. To further understand the role of GP5 in PRRSV induced cell apoptosis, we established Marc-145 cell lines stably expressing full-length GP5, GP5Δ84-96 (aa 84-96 deletion), and GP5Δ97-119 (aa 97-119 deletion). Cell proliferation, cell cycle progression, cell apoptosis and virus replication in these cell lines were evaluated. Neither truncated nor full-length GP5 induced cell apoptosis in Marc-145 cells. However, GP5Δ97-119, but not full-length or GP5Δ84-96, induced a cell cycle arrest at the G2/M phase resulting in a reduction in the growth of Marc-145 cells. Additionally, GP5Δ84-96 inhibited the replication of PRRSV in Marc-145 cells through induction of IFN-β. These findings suggest that PRRSV GP5 is not responsible for inducing cell apoptosis in Marc-145 cells under these experimental conditions; however it has other important roles in virus/host cell biology. - Highlights: • Marc-145 cell lines stable expression PRRSV GP5 or truncated GP5 were constructed. • GP5Δ97-119 expression in Marc-145 cell induced cell cycle arrest at G2/M phase. • Expression of GP5 and truncated GP5 could not induce Marc-145 cells apoptosis. • PRRSV replication in Marc-145-GP5Δ84-96 was significantly inhibited

  11. Contribution of radon and radon daughters to respiratory cancer

    International Nuclear Information System (INIS)

    This article reviews studies on the contribution of radon and radon daughters to respiratory cancer and proposes recommendations for further research, particularly a national radon survey. The steady-state outdoor radon concentration averages 200 pCi/m3, and indoor levels are about 4 times higher. The primary source of radon in homes is the underlying soil; entry depends on multiple variables and reduced ventilation for energy conservation increases indoor radon levels. Occupational exposures are expressed in units of radon daughter potential energy concentration or working level (WL). Cumulative exposure is the product of the working level and the time exposed. The unit for cumulative exposure is the working level month (WLM). The occupational standard for radon exposure is 4 WLM/year, and 2 WLM/year has been suggested as a guideline for remedial action in homes. Epidemiologic studies show that miners with cumulative radon daughter exposures somewhat below 100 WLM have excess lung cancer mortality. Some 3% to 8% of miners studied have developed lung cancer attributable to radon daughters. All of the underground mining studies show an increased risk of lung cancer with radon daughter exposure. All cell types of lung cancer increased with radon exposure. If radon and smoking act in a multiplicative manner, then the risk for smokers could be 10 times that for nonsmokers. The potential risk of lung cancer appears to be between 1 and 2 per 10,000/WLM, which yields a significant number of lung cancers as some 220 million persons in the United States are exposed on average to 10 to 20 WLM/lifetime

  12. The DR6 protein from human herpesvirus-6B induces p53-independent cell cycle arrest in G{sub 2}/M

    Energy Technology Data Exchange (ETDEWEB)

    Schleimann, Mariane H.; Hoberg, Søren; Solhøj Hansen, Aida; Bundgaard, Bettina; Witt, Christoffer T.; Kofod-Olsen, Emil; Höllsberg, Per, E-mail: ph@microbiology.au.dk

    2014-03-15

    HHV-6B infection inhibits cell proliferation in G{sub 2}/M, but no protein has so far been recognized to exert this function. Here we identify the protein product of direct repeat 6, DR6, as an inhibitor of G{sub 2}/M cell-cycle progression. Transfection of DR6 reduced the total number of cells compared with mock-transfected cells. Lentiviral transduction of DR6 inhibited host cell DNA synthesis in a p53-independent manner, and this inhibition was DR6 dose-dependent. A deletion of 66 amino acids from the N-terminal part of DR6 prevented efficient nuclear translocation and the ability to inhibit DNA synthesis. DR6-induced accumulation of cells in G{sub 2}/M was accompanied by an enhanced expression of cyclin B1 that accumulated predominantly in the cytoplasm. Pull-down of cyclin B1 brought down pCdk1 with the inactivating phosphorylation at Tyr15. Together, DR6 delays cell cycle with an accumulation of cells in G{sub 2}/M and thus might be involved in HHV-6B-induced cell-cycle arrest. - Highlights: • HHV-6B-encoded DR6 protein inhibits cell proliferation. • DR6 inhibits host cell DNA synthesis independent of p53. • DR6 delays the cell cycle in G{sub 2}/M. • An N-terminal sequence is necessary for DR6 function. • DR6 induces cytoplasmic accumulation of cyclin B1.

  13. Upregulation of the growth arrest-specific-2 in recurrent colorectal cancers, and its susceptibility to chemotherapy in a model cell system.

    Science.gov (United States)

    Huang, Chi-Jung; Lee, Chia-Long; Yang, Shung-Haur; Chien, Chih-Cheng; Huang, Chi-Cheng; Yang, Ruey-Neng; Chang, Chun-Chao

    2016-07-01

    Colorectal cancer (CRC) is one of the most common life-threatening malignances worldwide. CRC relapse markedly decreases the 5-year survival of patients following surgery. Aberrant expression of genes involved in pathways regulating the cell cycle, cell proliferation, or cell death are frequently reported in CRC tumorigenesis. We hypothesized that genes involved in CRC relapse might serve as prognostic indicators. We first evaluated the significance of gene sequences in the feces of patients with CRC relapse by consulting a public database. Tumorigenesis of target tissues was tested through tumor cell growth, cell cycle regulation, and chemotherapeutic efficacy. We found a highly significant correlation between CRC relapse and growth arrest-specific 2 (GAS2) gene expression. Based on cell models, the overexpressed GAS2 was associated with cellular growth rate, cell cycle regulation, and with chemotherapeutic sensitivity. Cell division was impaired by treating cells with 2-[4-(7-chloro-2-quinoxalinyloxy)phenoxy]-propionic acid (XK469), even when the cells were overexpressing GAS2. Thus, downregulation of GAS2 expression might control CRC relapse after curative resection. GAS2 could serve as a noninvasive marker from the feces of patients with prediagnosed CRC. Our findings suggest that GAS2 could have potential clinical applications for predicting early CRC relapse after radical resection, and that XK469 might impair tumor cell division by reducing GAS2 expression or blocking its cellular translocation. This will help in selecting the best therapeutic option, 5-fluorouracil in combination with XK469, for patients overexpressing GAS2 in CRC cells. Thus, GAS2 might act as a prognostic biomolecule and potential therapeutic target in patients with CRC relapse. PMID:27085973

  14. Resveratrol abrogates the Temozolomide-induced G2 arrest leading to mitotic catastrophe and reinforces the Temozolomide-induced senescence in glioma cells

    International Nuclear Information System (INIS)

    Temozolomide (TMZ) is the most widely used drug to treat glioblastoma (GBM), which is the most common and aggressive primary tumor of the Central Nervous System and one of the hardest challenges in oncotherapy. TMZ is an alkylating agent that induces autophagy, apoptosis and senescence in GBM cells. However, therapy with TMZ increases survival after diagnosis only from 12 to 14.4 months, making the development of combined therapies to treat GBM fundamental. One candidate for GBM therapy is Resveratrol (Rsv), which has additive toxicity with TMZ in several glioma cells in vitro and in vivo. However, the mechanism of Rsv and TMZ additive toxicity, which is the aim of the present work, is not clear, especially concerning cell cycle dynamics and long term effects. Glioma cell lines were treated with Rsv and TMZ, alone or in combinations, and the induction and the role of autophagy, apoptosis, cell cycle dynamics, protein expression and phosphorylation status were measured. We further evaluated the long term senescence induction and clonogenic capacity. As expected, temozolomide caused a G2 cell cycle arrest and extensive DNA damage response. Rsv did not reduced this response, even increasing pATM, pChk2 and gammaH2Ax levels, but abrogated the temozolomide-induced G2 arrest, increasing levels of cyclin B and pRb(S807/811) and reducing levels of pWee1(S642) and pCdk1(Y15). This suggests a cellular state of forced passage through G2 checkpoint despite large DNA damage, a scenario that may produce mitotic catastrophe. Indeed, the proportion of cells with high nuclear irregularity increased from 6 to 26% in 48 h after cotreatment. At a long term, a reduction in clonogenic capacity was observed, accompanied by a large induction of senescence. The presence of Rsv forces cells treated with TMZ through mitosis leading to mitotic catastrophe and senescence, reducing the clonogenic capacity of glioma cells and increasing the chronic effects of temozolomide

  15. Sinomenine prevents metastasis of human osteosarcoma cells via S phase arrest and suppression of tumor-related neovascularization and osteolysis through the CXCR4-STAT3 pathway.

    Science.gov (United States)

    Xie, Tao; Ren, Hai-Yong; Lin, Hai-Qing; Mao, Jin-Ping; Zhu, Ting; Wang, Sheng-Dong; Ye, Zhao-Ming

    2016-05-01

    Osteosarcoma is the most common primary malignant tumor of the bone. The long-term survivals continue to be unsatisfactory for patients with metastatic and recurrent disease. Metastasis is still a severe challenge in osteosarcoma treatment. Sinomenine, an alkaloid from traditional Chinese medicine, has been proved to possess potent antitumor and anti-invasion effect on various cancers. However, the effect of sinomenine on human osteosarcoma and the underlying mechanisms remains unknown. We report here that sinomenine inhibited proliferation by inducing S phase arrest and suppressing the clone formation. Significant inhibitory effects were found in invasion and metastasis in osteosarcoma, but little cytotoxicity was observed in tested concentrations. Exposure to sinomenine resulted in suppression of invasion and migration in osteosarcoma cells as well as tube formation ability in the human umbilical vein endothelial cells (HUVEC) and U2OS cells. Furthermore, it demonstrated that CXCR4 played a key role contributing to invasion in osteosarcoma which is considered to be a core target site in sinomenine treatment. Sinomenine inhibited invasion by suppressing CXCR4 and STAT3 phosphorylation then downregulating the expression of MMP-2, MMP-9, RANKL, VEGF downstream. In addition, then RANKL-mediated bone destruction stimulated by osteoclastogenesis and VEGF-related neovascularization were restrained. Importantly, in vivo, sinomenine suppressed proliferation, osteoclastogenesis and bone destruction. Through these various comprehensive means, sinomenine inhibits metastasis in osteosarcoma. Taken together, our results revealed that sinomenine caused S phase arrest, inhibited invasion and metastasis via suppressing the CXCR4-STAT3 pathway and then osteoclastogenesis-mediated bone destruction and neovascularization in osteosarcoma. Sinomenine is therefore a promising adjuvant agent for metastasis control in osteosarcoma. PMID:26983669

  16. Dactylone inhibits epidermal growth factor-induced transformation and phenotype expression of human cancer cells and induces G1-S arrest and apoptosis.

    Science.gov (United States)

    Fedorov, Sergey N; Shubina, Larisa K; Bode, Ann M; Stonik, Valentin A; Dong, Zigang

    2007-06-15

    The marine natural chamigrane-type sesquiterpenoid, dactylone, is closely related to secondary metabolites of some edible species of red algae. In the present study, the effect of dactylone was tested on the mouse skin epidermal JB6 P+ Cl41 cell line and its stable transfectants as well as on several human tumor cell lines, including lung (H460), colon (HCT-116), and skin melanomas (SK-MEL-5 and SK-MEL-28). This natural product was effective at nontoxic doses as a cancer-preventive agent, which exerted its actions, at least in part, through the inhibition of cyclin D3 and Cdk4 expression and retinoblastoma tumor suppressor protein (Rb) phosphorylation. The inhibition of these cell cycle components was followed by cell cycle arrest at the G1-S transition with subsequent p53-independent apoptosis. Therefore, these data showed that application of dactylone and related compounds may lead to decreased malignant cell transformation and/or decreased tumor cell proliferation. PMID:17575161

  17. The father-daughter dance: the relationship between father-daughter relationship quality and daughters' stress response.

    Science.gov (United States)

    Byrd-Craven, Jennifer; Auer, Brandon J; Granger, Douglas A; Massey, Amber R

    2012-02-01

    The goal of the study was to determine whether father-daughter relationship quality is related to activity of the hypothalamic-pituitary-adrenal (HPA) axis (salivary cortisol) and autonomic nervous system (salivary alpha-amylase, sAA) in late adolescence-emerging adulthood during peer interactions. In the 1st study, reported father-daughter relationships characterized by rejection, chaos, and coercion had lower morning cortisol levels and were temperamentally more sensitive to emotional changes. In the 2nd study, young women who reported father-daughter relationships characterized by warmth, autonomy, support, and structure had lower pretask cortisol levels, and they had attenuated cortisol responses to problem discussion with a friend. In contrast, those who reported father-daughter relationships characterized by rejection, chaos, and coercion had higher pretask cortisol levels, had elevated cortisol in response to problem discussion with a friend, and were more likely to self-disclose about psychosocial stressors. No differences were observed between reported father-daughter relationship quality and sAA levels or task-related reactivity. The findings suggest that father-daughter interactions potentially influence both social cognition and HPA reactivity to developmentally salient stressors in young women. PMID:22182338

  18. Anticancer activity of taraxerol acetate in human glioblastoma cells and a mouse xenograft model via induction of autophagy and apoptotic cell death, cell cycle arrest and inhibition of cell migration.

    Science.gov (United States)

    Hong, Jing-Fang; Song, Ying-Fang; Liu, Zheng; Zheng, Zhao-Cong; Chen, Hong-Jie; Wang, Shou-Sen

    2016-06-01

    The aim of the present study was to investigate the in vitro and in vivo anticancer and apoptotic effects of taraxerol acetate in U87 human glioblastoma cells. The effects on cell cycle phase distribution, cell cycle-associated proteins, autophagy, DNA fragmentation and cell migration were assessed. Cell viability was determined using the MTT assay, and phase contrast and fluorescence microscopy was utilized to determine the viability and apoptotic morphological features of the U87 cells. Flow cytometry using propidium iodide and Annexin V-fluorescein isothiocyanate demonstrated the effect of taraxerol acetate on the cell cycle phase distribution and apoptosis induction. Western blot analysis was performed to investigate the effect of the taraxerol acetate on cell cycle‑associated proteins and autophagy‑linked LC3B‑II proteins. The results demonstrated that taraxerol acetate induced dose‑ and time‑dependent cytotoxic effects in the U87 cells. Apoptotic induction following taraxerol acetate treatment was observed and the percentage of apoptotic cells increased from 7.3% in the control cells, to 16.1, 44.1 and 76.7% in the 10, 50 and 150 µM taraxerol acetate‑treated cells, respectively. Furthermore, taraxerol acetate treatment led to sub‑G1 cell cycle arrest with a corresponding decrease in the number of S‑phase cells. DNA fragments were observed as a result of the gel electrophoresis experiment following taraxerol acetate treatment. To investigate the inhibitory effects of taraxerol acetate on the migration of U87 cell, a wound healing assay was conducted. The number of cells that migrated to the scratched area decreased significantly following treatment with taraxerol acetate. In addition, taraxerol acetate inhibited tumor growth in a mouse xenograft model. Administration of 0.25 and 0.75 µg/g taraxerol acetate reduced the tumor weight from 1.2 g in the phosphate‑buffered saline (PBS)‑treated group (control) to 0.81 and 0.42

  19. Anticancer activity of taraxerol acetate in human glioblastoma cells and a mouse xenograft model via induction of autophagy and apoptotic cell death, cell cycle arrest and inhibition of cell migration