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Sample records for 17alpha-estradiol arrests cell

  1. 17{alpha}-Estradiol arrests cell cycle progression at G{sub 2}/M and induces apoptotic cell death in human acute leukemia Jurkat T cells

    SciTech Connect

    Jun, Do Youn; Park, Hae Sun; Kim, Jun Seok; Kim, Jong Sik; Park, Wan; Song, Bang Ho; Kim, Hee-Sook; Taub, Dennis; Kim, Young Ho

    2008-09-15

    A pharmacological dose (2.5-10 {mu}M) of 17{alpha}-estradiol (17{alpha}-E{sub 2}) exerted a cytotoxic effect on human leukemias Jurkat T and U937 cells, which was not suppressed by the estrogen receptor (ER) antagonist ICI 182,780. Along with cytotoxicity in Jurkat T cells, several apoptotic events including mitochondrial cytochrome c release, activation of caspase-9, -3, and -8, PARP degradation, and DNA fragmentation were induced. The cytotoxicity of 17{alpha}-E{sub 2} was not blocked by the anti-Fas neutralizing antibody ZB-4. While undergoing apoptosis, there was a remarkable accumulation of G{sub 2}/M cells with the upregulatoin of cdc2 kinase activity, which was reflected in the Thr56 phosphorylation of Bcl-2. Dephosphorylation at Tyr15 and phosphorylation at Thr161 of cdc2, and significant increase in the cyclin B1 level were underlying factors for the cdc2 kinase activation. Whereas the 17{alpha}-E{sub 2}-induced apoptosis was completely abrogated by overexpression of Bcl-2 or by pretreatment with the pan-caspase inhibitor z-VAD-fmk, the accumulation of G{sub 2}/M cells significantly increased. The caspase-8 inhibitor z-IETD-fmk failed to influence 17{alpha}-E{sub 2}-mediated caspase-9 activation, but it markedly reduced caspase-3 activation and PARP degradation with the suppression of apoptosis, indicating the contribution of caspase-8; not as an upstream event of the mitochondrial cytochrome c release, but to caspase-3 activation. In the presence of hydroxyurea, which blocked the cell cycle progression at the G{sub 1}/S boundary, 17{alpha}-E{sub 2} failed to induce the G{sub 2}/M arrest as well as apoptosis. These results demonstrate that the cytotoxicity of 17{alpha}-E{sub 2} toward Jurkat T cells is attributable to apoptosis mainly induced in G{sub 2}/M-arrested cells, in an ER-independent manner, via a mitochondria-dependent caspase pathway regulated by Bcl-2.

  2. Gene copy number and cell cycle arrest

    NASA Astrophysics Data System (ADS)

    Ghosh, Bhaswar; Bose, Indrani

    2006-03-01

    The cell cycle is an orderly sequence of events which ultimately lead to the division of a single cell into two daughter cells. In the case of DNA damage by radiation or chemicals, the damage checkpoints in the G1 and G2 phases of the cell cycle are activated. This results in an arrest of the cell cycle so that the DNA damage can be repaired. Once this is done, the cell continues with its usual cycle of activity. We study a mathematical model of the DNA damage checkpoint in the G2 phase which arrests the transition from the G2 to the M (mitotic) phase of the cell cycle. The tumor suppressor protein p53 plays a key role in activating the pathways leading to cell cycle arrest in mammalian systems. If the DNA damage is severe, the p53 proteins activate other pathways which bring about apoptosis, i.e., programmed cell death. Loss of the p53 gene results in the proliferation of cells containing damaged DNA, i.e., in the growth of tumors which may ultimately become cancerous. There is some recent experimental evidence which suggests that the mutation of a single copy of the p53 gene (in the normal cell each gene has two identical copies) is sufficient to trigger the formation of tumors. We study the effect of reducing the gene copy number of the p53 and two other genes on cell cycle arrest and obtain results consistent with experimental observations.

  3. Synchronized Cell Cycle Arrest Promotes Osteoclast Differentiation

    PubMed Central

    Kwon, Minsuk; Kim, Jin-Man; Lee, Kyunghee; Park, So-Young; Lim, Hyun-Sook; Kim, Taesoo; Jeong, Daewon

    2016-01-01

    Osteoclast progenitors undergo cell cycle arrest before differentiation into osteoclasts, induced by exposure to macrophage colony-stimulating factor (M-CSF) and receptor activator of nuclear factor-κB ligand (RANKL). The role of such cell cycle arrest in osteoclast differentiation has remained unclear, however. We here examined the effect of synchronized cell cycle arrest on osteoclast formation. Osteoclast progenitors deprived of M-CSF in culture adopted a uniform morphology and exhibited cell cycle arrest at the G0–G1 phase in association with both down-regulation of cyclins A and D1 as well as up-regulation of the cyclin-dependent kinase inhibitor p27Kip1. Such M-CSF deprivation also promoted the differentiation of osteoclast progenitors into multinucleated osteoclasts expressing high levels of osteoclast marker proteins such as NFATc1, c-Fos, Atp6v0d2, cathepsin K, and integrin β3 on subsequent exposure to M-CSF and RANKL. Our results suggest that synchronized arrest and reprogramming of osteoclast progenitors renders them poised to respond to inducers of osteoclast formation. Further characterization of such effects may facilitate induction of the differentiation of heterogeneous and multipotent cells into desired cell lineages. PMID:27517906

  4. Synchronized Cell Cycle Arrest Promotes Osteoclast Differentiation.

    PubMed

    Kwon, Minsuk; Kim, Jin-Man; Lee, Kyunghee; Park, So-Young; Lim, Hyun-Sook; Kim, Taesoo; Jeong, Daewon

    2016-01-01

    Osteoclast progenitors undergo cell cycle arrest before differentiation into osteoclasts, induced by exposure to macrophage colony-stimulating factor (M-CSF) and receptor activator of nuclear factor-κB ligand (RANKL). The role of such cell cycle arrest in osteoclast differentiation has remained unclear, however. We here examined the effect of synchronized cell cycle arrest on osteoclast formation. Osteoclast progenitors deprived of M-CSF in culture adopted a uniform morphology and exhibited cell cycle arrest at the G₀-G₁ phase in association with both down-regulation of cyclins A and D1 as well as up-regulation of the cyclin-dependent kinase inhibitor p27(Kip1). Such M-CSF deprivation also promoted the differentiation of osteoclast progenitors into multinucleated osteoclasts expressing high levels of osteoclast marker proteins such as NFATc1, c-Fos, Atp6v0d2, cathepsin K, and integrin β3 on subsequent exposure to M-CSF and RANKL. Our results suggest that synchronized arrest and reprogramming of osteoclast progenitors renders them poised to respond to inducers of osteoclast formation. Further characterization of such effects may facilitate induction of the differentiation of heterogeneous and multipotent cells into desired cell lineages. PMID:27517906

  5. Parvovirus infection-induced cell death and cell cycle arrest

    PubMed Central

    Chen, Aaron Yun; Qiu, Jianming

    2011-01-01

    The cytopathic effects induced during parvovirus infection have been widely documented. Parvovirus infection-induced cell death is often directly associated with disease outcomes (e.g., anemia resulting from loss of erythroid progenitors during parvovirus B19 infection). Apoptosis is the major form of cell death induced by parvovirus infection. However, nonapoptotic cell death, namely necrosis, has also been reported during infection of the minute virus of mice, parvovirus H-1 and bovine parvovirus. Recent studies have revealed multiple mechanisms underlying the cell death during parvovirus infection. These mechanisms vary in different parvoviruses, although the large nonstructural protein (NS)1 and the small NS proteins (e.g., the 11 kDa of parvovirus B19), as well as replication of the viral genome, are responsible for causing infection-induced cell death. Cell cycle arrest is also common, and contributes to the cytopathic effects induced during parvovirus infection. While viral NS proteins have been indicated to induce cell cycle arrest, increasing evidence suggests that a cellular DNA damage response triggered by an invading single-stranded parvoviral genome is the major inducer of cell cycle arrest in parvovirus-infected cells. Apparently, in response to infection, cell death and cell cycle arrest of parvovirus-infected cells are beneficial to the viral cell lifecycle (e.g., viral DNA replication and virus egress). In this article, we will discuss recent advances in the understanding of the mechanisms underlying parvovirus infection-induced cell death and cell cycle arrest. PMID:21331319

  6. Cell cycle arrest is not yet senescence, which is not just cell cycle arrest: terminology for TOR-driven aging.

    PubMed

    Blagosklonny, Mikhail V

    2012-03-01

    Cell cycle arrest is not yet senescence. When the cell cycle is arrested, an inappropriate growth-promotion converts an arrest into senescence (geroconversion). By inhibiting the growth-promoting mTOR pathway, rapamycin decelerates geroconversion of the arrested cells. And as a striking example, while causing arrest, p53 may decelerate or suppress geroconversion (in some conditions). Here I discuss the meaning of geroconversion and also the terms gerogenes, gerossuppressors, gerosuppressants, gerogenic pathways, gero-promoters, hyperfunction and feedback resistance, regenerative potential, hypertrophy and secondary atrophy, pro-gerogenic and gerogenic cells. PMID:22394614

  7. Testosterone metabolism in human skin cells in vitro and its interaction with estradiol and dutasteride.

    PubMed

    Münster, U; Hammer, S; Blume-Peytavi, U; Schäfer-Korting, M

    2003-01-01

    Since the limited knowledge of cutaneous drug metabolism can impair the development of specifically acting topical dermatics and transdermal application systems, the cell-type-specific androgen metabolism in human skin and its inhibition by drugs were investigated. Cultured human foreskin and scalp skin keratinocytes and fibroblasts as well as occipital scalp dermal papilla cells (DPC) were incubated with testosterone 10(-6) and 10(-8)M alone and in the presence of 17alpha-estradiol, 17beta-estradiol or dutasteride for 24 h. Androgens extracted from culture supernatants were subjected to thin-layer chromatography and quantified by beta-counting. In keratinocytes and DPC, dihydrotestosterone (DHT) was only formed to a low extent while androstenedione was the main metabolite. In fibroblasts, DHT formation was pronounced following 10(-8)M testosterone. Dutasteride 10(-8)M completely suppressed 5alpha-dihydro metabolite formation. 17alpha-Estradiol and 17beta-estradiol at nontoxic concentrations decreased 17-ketometabolites. Human skin regulates testosterone action by cell-type-specific activation or deactivation. Effects of 17alpha-estradiol in androgenetic alopecia are not due to 5alpha-reductase inhibition. Dutasteride may be useful in acne and androgenetic alopecia. PMID:14528059

  8. Digital Holographic Microscopy for Non-Invasive Monitoring of Cell Cycle Arrest in L929 Cells

    PubMed Central

    Falck Miniotis, Maria; Mukwaya, Anthonny; Gjörloff Wingren, Anette

    2014-01-01

    Digital holographic microscopy (DHM) has emerged as a powerful non-invasive tool for cell analysis. It has the capacity to analyse multiple parameters simultaneously, such as cell- number, confluence and phase volume. This is done while cells are still adhered and growing in their culture flask. The aim of this study was to investigate whether DHM was able to monitor drug-induced cell cycle arrest in cultured cells and thus provide a non-disruptive alternative to flow cytometry. DHM parameters from G1 and G2/M cell cycle arrested L929 mouse fibroblast cells were collected. Cell cycle arrest was verified with flow cytometry. This study shows that DHM is able to monitor phase volume changes corresponding to either a G1 or G2/M cell cycle arrest. G1-phase arrest with staurosporine correlated with a decrease in the average cell phase volume and G2/M-phase arrest with colcemid and etoposide correlated with an increase in the average cell phase volume. Importantly, DHM analysis of average cell phase volume was of comparable accuracy to flow cytometric measurement of cell cycle phase distribution as recorded following dose-dependent treatment with etoposide. Average cell phase volume changes in response to treatment with cell cycle arresting compounds could therefore be used as a DHM marker for monitoring cell cycle arrest in cultured mammalian cells. PMID:25208094

  9. PTEN mediates Notch-dependent stalk cell arrest in angiogenesis.

    PubMed

    Serra, Helena; Chivite, Iñigo; Angulo-Urarte, Ana; Soler, Adriana; Sutherland, James D; Arruabarrena-Aristorena, Amaia; Ragab, Anan; Lim, Radiance; Malumbres, Marcos; Fruttiger, Marcus; Potente, Michael; Serrano, Manuel; Fabra, Àngels; Viñals, Francesc; Casanovas, Oriol; Pandolfi, Pier Paolo; Bigas, Anna; Carracedo, Arkaitz; Gerhardt, Holger; Graupera, Mariona

    2015-07-31

    Coordinated activity of VEGF and Notch signals guides the endothelial cell (EC) specification into tip and stalk cells during angiogenesis. Notch activation in stalk cells leads to proliferation arrest via an unknown mechanism. By using gain- and loss-of-function gene-targeting approaches, here we show that PTEN is crucial for blocking stalk cell proliferation downstream of Notch, and this is critical for mouse vessel development. Endothelial deletion of PTEN results in vascular hyperplasia due to a failure to mediate Notch-induced proliferation arrest. Conversely, overexpression of PTEN reduces vascular density and abrogates the increase in EC proliferation induced by Notch blockade. PTEN is a lipid/protein phosphatase that also has nuclear phosphatase-independent functions. We show that both the catalytic and non-catalytic APC/C-Fzr1/Cdh1-mediated activities of PTEN are required for stalk cells' proliferative arrest. These findings define a Notch-PTEN signalling axis as an orchestrator of vessel density and implicate the PTEN-APC/C-Fzr1/Cdh1 hub in angiogenesis.

  10. Cellular origin of cancer: dedifferentiation or stem cell maturation arrest?

    PubMed Central

    Sell, S

    1993-01-01

    Given the fundamental principle that cancer must arise from a cell that has the potential to divide, two major nonexclusive hypotheses of the cellular origin of cancer are that malignancy arises a) from stem cells due to maturation arrest or b) from dedifferentiation of mature cells that retain the ability to proliferate. The role of stem cells in carcinogenesis is clearly demonstrated in teratocarcinomas. The malignant stem cells of teratocarcinomas are derived from normal multipotent stem cells and have the potential to differentiate into normal benign mature tissue. A widely studied model supporting dedifferentiation has been the putative origin of hepatocarcinomas from "premalignant" foci and nodules induced in the rat liver by chemicals. However, the dedifferentiation concept for hepatocarcinogenesis is challenged by more recent interpretations indicating that hepatocellular carcinoma arises from maturation arrest caused by aberrant differentiation of determined stem cells. Either hypothesis is supported by the cellular changes that occur in the rodent liver after different hepatocarcinogenic regimens. The formation of foci and nodules from altered hepatocytes supports dedifferentiation; the proliferation of small oval cells with the potential to differentiate into either biliary ducts or hepatocytes supports arrested maturation of determined stem cells. It is now postulated that foci and nodular change reflect adaptive changes to the toxic effects of carcinogens and not "preneoplastic" stages to cancer. The stem cell model predicts that genotoxic chemicals induce mutations in the determined stem cell which may be expressed in its progeny. Proliferation of initiated cells is induced by promoting events which also allow additional mutations to occur. PMID:7516873

  11. Computation Molecular Kinetics Model of HZE Induced Cell Cycle Arrest

    NASA Technical Reports Server (NTRS)

    Cucinotta, Francis A.; Ren, Lei

    2004-01-01

    Cell culture models play an important role in understanding the biological effectiveness of space radiation. High energy and charge (HZE) ions produce prolonged cell cycle arrests at the G1/S and G2/M transition points in the cell cycle. A detailed description of these phenomena is needed to integrate knowledge of the expression of DNA damage in surviving cells, including the determination of relative effectiveness factors between different types of radiation that produce differential types of DNA damage and arrest durations. We have developed a hierarchical kinetics model that tracks the distribution of cells in various cell phase compartments (early G1, late G1, S, G2, and M), however with transition rates that are controlled by rate-limiting steps in the kinetics of cyclin-cdk's interactions with their families of transcription factors and inhibitor molecules. The coupling of damaged DNA molecules to the downstream cyclin-cdk inhibitors is achieved through a description of the DNA-PK and ATM signaling pathways. For HZE irradiations we describe preliminary results, which introduce simulation of the stochastic nature of the number of direct particle traversals per cell in the modulation of cyclin-cdk and cell cycle population kinetics. Comparison of the model to data for fibroblast cells irradiated photons or HZE ions are described.

  12. Pneumococcal Pneumolysin Induces DNA Damage and Cell Cycle Arrest

    PubMed Central

    Rai, Prashant; He, Fang; Kwang, Jimmy; Engelward, Bevin P.; Chow, Vincent T.K.

    2016-01-01

    Streptococcus pneumoniae produces pneumolysin toxin as a key virulence factor against host cells. Pneumolysin is a cholesterol-dependent cytolysin (CDC) toxin that forms lytic pores in host membranes and mediates pneumococcal disease pathogenesis by modulating inflammatory responses. Here, we show that pneumolysin, which is released during bacterial lysis, induces DNA double strand breaks (DSBs), as indicated by ataxia telangiectasia mutated (ATM)-mediated H2AX phosphorylation (γH2AX). Pneumolysin-induced γH2AX foci recruit mediator of DNA damage checkpoint 1 (MDC1) and p53 binding protein 1 (53BP1), to sites of DSBs. Importantly, results show that toxin-induced DNA damage precedes cell cycle arrest and causes apoptosis when DNA-dependent protein kinase (DNA-PK)-mediated non-homologous end joining is inhibited. Further, we observe that cells that were undergoing DNA replication harbored DSBs in greater frequency during pneumolysin treatment. This observation raises the possibility that DSBs might be arising as a result of replication fork breakdown. Additionally, neutralizing the oligomerization domain of pneumolysin with monoclonal antibody suppresses DNA damage and also cell cycle arrest, indicating that pneumolysin oligomerization is important for causing DNA damage. Taken together, this study reveals a previously unidentified ability of pneumolysin to induce cytotoxicity via DNA damage, with implications in the pathophysiology of S. pneumoniae infection. PMID:27026501

  13. Pneumococcal Pneumolysin Induces DNA Damage and Cell Cycle Arrest.

    PubMed

    Rai, Prashant; He, Fang; Kwang, Jimmy; Engelward, Bevin P; Chow, Vincent T K

    2016-01-01

    Streptococcus pneumoniae produces pneumolysin toxin as a key virulence factor against host cells. Pneumolysin is a cholesterol-dependent cytolysin (CDC) toxin that forms lytic pores in host membranes and mediates pneumococcal disease pathogenesis by modulating inflammatory responses. Here, we show that pneumolysin, which is released during bacterial lysis, induces DNA double strand breaks (DSBs), as indicated by ataxia telangiectasia mutated (ATM)-mediated H2AX phosphorylation (γH2AX). Pneumolysin-induced γH2AX foci recruit mediator of DNA damage checkpoint 1 (MDC1) and p53 binding protein 1 (53BP1), to sites of DSBs. Importantly, results show that toxin-induced DNA damage precedes cell cycle arrest and causes apoptosis when DNA-dependent protein kinase (DNA-PK)-mediated non-homologous end joining is inhibited. Further, we observe that cells that were undergoing DNA replication harbored DSBs in greater frequency during pneumolysin treatment. This observation raises the possibility that DSBs might be arising as a result of replication fork breakdown. Additionally, neutralizing the oligomerization domain of pneumolysin with monoclonal antibody suppresses DNA damage and also cell cycle arrest, indicating that pneumolysin oligomerization is important for causing DNA damage. Taken together, this study reveals a previously unidentified ability of pneumolysin to induce cytotoxicity via DNA damage, with implications in the pathophysiology of S. pneumoniae infection. PMID:27026501

  14. Pseudolaric Acid B Induced Cell Cycle Arrest, Autophagy and Senescence in Murine Fibrosarcoma L929 Cell

    PubMed Central

    hua Yu, Jing; yu Liu, Chun; bin Zheng, Gui; Zhang, Li Ying; hui Yan, Ming; yan Zhang, Wen; ying Meng, Xian; fang Yu, Xiao

    2013-01-01

    Objective: PAB induced various cancer cell apoptosis, cell cycle arrest and senescence. But in cell line murine fibrosarcoma L929, PAB did not induce apoptosis, but autophagy, therefore it was thought by us as a good model to research the relationship of cell cycle arrest, autophagy and senescence bypass apoptosis. Methods: Inhibitory ratio was assessed by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) analysis. Phase contrast microscopy visualized cell morphology. Hoechst 33258 staining for nuclear change, propidium iodode (PI) staining for cell cycle, monodansylcadaverine (MDC) staining for autophagy, and rodanmine 123 staining for mitochondrial membrane potential (MMP) were measured by fluorescence microscopy or flowcytometry. Apoptosis was determined by DNA ladder test. Protein kinase C (PKC) activity was detected by PKC assay kit. SA-β-galactosidase assay was used to detect senescence. Protein expression was examined by western blot. Results: PAB inhibited L929 cell growth in time-and dose-dependent manner. At 12 h, 80 μmol/L PAB induced obvious mitotic arrest; at 24 h, PAB began to induce autophagy; at 36 h, cell-treated with PAB slip into G1 cell cycle; and 3 d PAB induced senescence. In time sequence PAB induced firstly cell cycle arrest, then autophagy, then slippage into G1 phase, lastly senescence. Senescent cells had high level of autophagy, inhibiting autophagy led to apoptosis, and no senescence. PAB activated PKC activity to induce cell cycle arrest, autophagy and senescence, inhibiting PKC activity suppressed cell cycle arrest, autophagy and senescence. Conclusion: PAB induced cell cycle arrest, autophagy and senescence in murine fibrosarcoma L929 cell through PKC. PMID:23630435

  15. Astaxanthin Inhibits Proliferation and Induces Apoptosis and Cell Cycle Arrest of Mice H22 Hepatoma Cells

    PubMed Central

    Shao, Yiye; Ni, Yanbo; Yang, Jing; Lin, Xutao; Li, Jun; Zhang, Lixia

    2016-01-01

    Background It is widely recognized that astaxanthin (ASX), a member of the carotenoid family, has strong biological activities including antioxidant, anti-inflammation, and immune-modulation activities. Previous studies have confirmed that ASX can effectively inhibit hepatoma cells in vitro. Material/Methods MTT was used to assay proliferation of mice H22 cells, and flow cytometry was used to determine apoptosis and cell cycle arrest of H22 cells in vitro and in vivo. Moreover, anti-tumor activity of ASX was observed in mice. Results ASX inhibited the proliferation of H22 cells, promoted cell necrosis, and induced cell cycle arrest in G2 phase in vitro and in vivo. Conclusions This study indicated that ASX can inhibit proliferation and induce apoptosis and cell cycle arrest in mice H22 hepatoma cells in vitro and in vivo. PMID:27333866

  16. Cell Cycle Arrest and Cell Survival Induce Reverse Trends of Cardiolipin Remodeling

    PubMed Central

    Chao, Yu-Jen; Chang, Wan-Hsin; Ting, Hsiu-Chi; Chao, Wei-Ting; Hsu, Yuan-Hao Howard

    2014-01-01

    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. PMID:25422939

  17. Abnormal mitosis triggers p53-dependent cell cycle arrest in human tetraploid cells.

    PubMed

    Kuffer, Christian; Kuznetsova, Anastasia Yurievna; Storchová, Zuzana

    2013-08-01

    Erroneously arising tetraploid mammalian cells are chromosomally instable and may facilitate cell transformation. An increasing body of evidence shows that the propagation of mammalian tetraploid cells is limited by a p53-dependent arrest. The trigger of this arrest has not been identified so far. Here we show by live cell imaging of tetraploid cells generated by an induced cytokinesis failure that most tetraploids arrest and die in a p53-dependent manner after the first tetraploid mitosis. Furthermore, we found that the main trigger is a mitotic defect, in particular, chromosome missegregation during bipolar mitosis or spindle multipolarity. Both a transient multipolar spindle followed by efficient clustering in anaphase as well as a multipolar spindle followed by multipolar mitosis inhibited subsequent proliferation to a similar degree. We found that the tetraploid cells did not accumulate double-strand breaks that could cause the cell cycle arrest after tetraploid mitosis. In contrast, tetraploid cells showed increased levels of oxidative DNA damage coinciding with the p53 activation. To further elucidate the pathways involved in the proliferation control of tetraploid cells, we knocked down specific kinases that had been previously linked to the cell cycle arrest and p53 phosphorylation. Our results suggest that the checkpoint kinase ATM phosphorylates p53 in tetraploid cells after abnormal mitosis and thus contributes to proliferation control of human aberrantly arising tetraploids.

  18. EDD induces cell cycle arrest by increasing p53 levels.

    PubMed

    Smits, Veronique A J

    2012-02-15

    Tight regulation of p53 is essential for its central role in maintaining genome stability and tumor prevention. Here, EDD/ UBR5/hHyd, hereafter called EDD, is identified as a novel regulator of p53. Downregulation of EDD results in elevated p53 protein levels both in transformed and untransformed cells. Concomitant with a rise in p53, the levels of p21, a critical p53 target, are also elevated in these conditions. Surprisingly, EDD knockdown does not affect p53 protein stability, and p53 mRNA levels do not increase significantly upon EDD depletion. Consistent with the function of p53, EDD downregulation triggers a senescent phenotype in fibroblasts at later time points. In addition, the increased p53 levels upon EDD depletion cause a G(1) arrest, as co-depletion of EDD and p53 completely rescues this effect on cell cycle progression. PMID:22374670

  19. Programmed cell cycle arrest is required for infection of corn plants by the fungus Ustilago maydis.

    PubMed

    Castanheira, Sónia; Mielnichuk, Natalia; Pérez-Martín, José

    2014-12-01

    Ustilago maydis is a plant pathogen that requires a specific structure called infective filament to penetrate the plant tissue. Although able to grow, this filament is cell cycle arrested on the plant surface. This cell cycle arrest is released once the filament penetrates the plant tissue. The reasons and mechanisms for this cell cycle arrest are unknown. Here, we have tried to address these questions. We reached three conclusions from our studies. First, the observed cell cycle arrest is the result of the cooperation of at least two distinct mechanisms: one involving the activation of the DNA damage response (DDR) cascade; and the other relying on the transcriptional downregulation of Hsl1, a kinase that modulates the G2/M transition. Second, a sustained cell cycle arrest during the infective filament step is necessary for the virulence in U. maydis, as a strain unable to arrest the cell cycle was severely impaired in its ability to infect corn plants. Third, production of the appressorium, a structure required for plant penetration, is incompatible with an active cell cycle. The inability to infect plants by strains defective in cell cycle arrest seems to be caused by their failure to induce the appressorium formation process. In summary, our findings uncover genetic circuits to arrest the cell cycle during the growth of this fungus on the plant surface, thus allowing the penetration into plant tissue.

  20. α-Mangostin Induces Apoptosis and Cell Cycle Arrest in Oral Squamous Cell Carcinoma Cell

    PubMed Central

    Kwak, Hyun-Ho; Park, Bong-Soo

    2016-01-01

    Mangosteen has long been used as a traditional medicine and is known to have antibacterial, antioxidant, and anticancer effects. Although the effects of α-mangostin, a natural compound extracted from the pericarp of mangosteen, have been investigated in many studies, there is limited data on the effects of the compound in human oral squamous cell carcinoma (OSCC). In this study, α-mangostin was assessed as a potential anticancer agent against human OSCC cells. α-Mangostin inhibited cell proliferation and induced cell death in OSCC cells in a dose- and time-dependent manner with little to no effect on normal human PDLF cells. α-Mangostin treatment clearly showed apoptotic evidences such as nuclear fragmentation and accumulation of annexin V and PI-positive cells on OSCC cells. α-Mangostin treatment also caused the collapse of mitochondrial membrane potential and the translocation of cytochrome c from the mitochondria into the cytosol. The expressions of the mitochondria-related proteins were activated by α-mangostin. Treatment with α-mangostin also induced G1 phase arrest and downregulated cell cycle-related proteins (CDK/cyclin). Hence, α-mangostin specifically induces cell death and inhibits proliferation in OSCC cells via the intrinsic apoptosis pathway and cell cycle arrest at the G1 phase, suggesting that α-mangostin may be an effective agent for the treatment of OSCC. PMID:27478478

  1. Ras-mediated cell cycle arrest is altered by nuclear oncogenes to induce Schwann cell transformation.

    PubMed Central

    Ridley, A J; Paterson, H F; Noble, M; Land, H

    1988-01-01

    The cellular responses to ras and nuclear oncogenes were investigated in purified populations of rat Schwann cells. v-Ha-ras and SV40 large T cooperate to transform Schwann cells, inducing growth in soft agar and allowing proliferation in the absence of added mitogens. Expression of large T alone reduces their growth factor requirements but is insufficient to induce full transformation. In contrast, expression of v-Ha-ras leads to proliferation arrest in Schwann cells expressing a temperature-sensitive mutant of large T at the restrictive temperature. Cells arrest in either the G1 or G2/M phases of the cell cycle, and can re-enter cell division at the permissive temperature even after prolonged periods at the restrictive conditions. Oncogenic ras proteins also inhibit DNA synthesis when microinjected into Schwann cells. Adenovirus E1a and c-myc oncogenes behave similarly to SV40 large T. They cooperate with Ha-ras oncogenes to transform Schwann cells, and prevent ras-induced growth arrest. Thus nuclear oncogenes fundamentally alter the response of Schwann cells to a ras oncogene from cell cycle arrest to transformation. Images PMID:3049071

  2. Linalool Induces Cell Cycle Arrest and Apoptosis in Leukemia Cells and Cervical Cancer Cells through CDKIs

    PubMed Central

    Chang, Mei-Yin; Shieh, Den-En; Chen, Chung-Chi; Yeh, Ching-Sheng; Dong, Huei-Ping

    2015-01-01

    Plantaginaceae, a popular traditional Chinese medicine, has long been used for treating various diseases from common cold to cancer. Linalool is one of the biologically active compounds that can be isolated from Plantaginaceae. Most of the commonly used cytotoxic anticancer drugs have been shown to induce apoptosis in susceptible tumor cells. However, the signaling pathway for apoptosis remains undefined. In this study, the cytotoxic effect of linalool on human cancer cell lines was investigated. Water-soluble tetrazolium salts (WST-1) based colorimetric cellular cytotoxicity assay, was used to test the cytotoxic ability of linalool against U937 and HeLa cells, and flow cytometry (FCM) and genechip analysis were used to investigate the possible mechanism of apoptosis. These results demonstrated that linalool exhibited a good cytotoxic effect on U937 and HeLa cells, with the IC50 value of 2.59 and 11.02 μM, respectively, compared with 5-FU with values of 4.86 and 12.31 μM, respectively. After treating U937 cells with linalool for 6 h, we found an increased sub-G1 peak and a dose-dependent phenomenon, whereby these cells were arrested at the G0/G1 phase. Furthermore, by using genechip analysis, we observed that linalool can promote p53, p21, p27, p16, and p18 gene expression. Therefore, this study verified that linalool can arrest the cell cycle of U937 cells at the G0/G1 phase and can arrest the cell cycle of HeLa cells at the G2/M phase. Its mechanism facilitates the expression of the cyclin-dependent kinases inhibitors (CDKIs) p53, p21, p27, p16, and p18, as well as the non-expression of cyclin-dependent kinases (CDKs) activity. PMID:26703569

  3. Linalool Induces Cell Cycle Arrest and Apoptosis in Leukemia Cells and Cervical Cancer Cells through CDKIs.

    PubMed

    Chang, Mei-Yin; Shieh, Den-En; Chen, Chung-Chi; Yeh, Ching-Sheng; Dong, Huei-Ping

    2015-01-01

    Plantaginaceae, a popular traditional Chinese medicine, has long been used for treating various diseases from common cold to cancer. Linalool is one of the biologically active compounds that can be isolated from Plantaginaceae. Most of the commonly used cytotoxic anticancer drugs have been shown to induce apoptosis in susceptible tumor cells. However, the signaling pathway for apoptosis remains undefined. In this study, the cytotoxic effect of linalool on human cancer cell lines was investigated. Water-soluble tetrazolium salts (WST-1) based colorimetric cellular cytotoxicity assay, was used to test the cytotoxic ability of linalool against U937 and HeLa cells, and flow cytometry (FCM) and genechip analysis were used to investigate the possible mechanism of apoptosis. These results demonstrated that linalool exhibited a good cytotoxic effect on U937 and HeLa cells, with the IC50 value of 2.59 and 11.02 μM, respectively, compared with 5-FU with values of 4.86 and 12.31 μM, respectively. After treating U937 cells with linalool for 6 h, we found an increased sub-G1 peak and a dose-dependent phenomenon, whereby these cells were arrested at the G0/G1 phase. Furthermore, by using genechip analysis, we observed that linalool can promote p53, p21, p27, p16, and p18 gene expression. Therefore, this study verified that linalool can arrest the cell cycle of U937 cells at the G0/G1 phase and can arrest the cell cycle of HeLa cells at the G2/M phase. Its mechanism facilitates the expression of the cyclin-dependent kinases inhibitors (CDKIs) p53, p21, p27, p16, and p18, as well as the non-expression of cyclin-dependent kinases (CDKs) activity.

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

    PubMed

    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.

  5. Differential arrest and adhesion of tumor cells and microbeads in the microvasculature.

    PubMed

    Guo, Peng; Cai, Bin; Lei, Ming; Liu, Yang; Fu, Bingmei M

    2014-06-01

    To investigate the mechanical mechanisms behind tumor cell arrest in the microvasculature, we injected fluorescently labeled human breast carcinoma cells or similarly sized rigid beads into the systemic circulation of a rat. Their arrest patterns in the microvasculature of mesentery were recorded and quantified. We found that 93% of rigid beads were arrested either at arteriole-capillary intersections or in capillaries. Only 3% were at the capillary-postcapillary venule intersections and in postcapillary venules. In contrast, most of the flexible tumor cells were either entrapped in capillaries or arrested at capillary or postcapillary venule-postcapillary venule intersections and in postcapillary venules. Only 12% of tumor cells were arrested at the arteriole-capillary intersections. The differential arrest and adhesion of tumor cells and microbeads in the microvasculature was confirmed by a χ(2) test (p < 0.001). These results demonstrate that mechanical trapping was responsible for almost all the arrest of beads and half the arrest of tumor cells. Based on the measured geometry and blood flow velocities at the intersections, we also performed a numerical simulation using commercial software (ANSYS CFX 12.01) to depict the detailed distribution profiles of the velocity, shear rate, and vorticity at the intersections where tumor cells preferred to arrest and adhere. Simulation results reveal the presence of localized vorticity and shear rate regions at the turning points of the microvessel intersections, implying that hemodynamic factors play an important role in tumor cell arrest in the microcirculation. Our study helps elucidate long-debated issues related to the dominant factors in early-stage tumor hematogenous metastasis.

  6. Induction of G1 cell cycle arrest and apoptosis by berberine in bladder cancer cells.

    PubMed

    Yan, Keqiang; Zhang, Cheng; Feng, Jinbo; Hou, Lifang; Yan, Lei; Zhou, Zunlin; Liu, Zhaoxu; Liu, Cheng; Fan, Yidon; Zheng, Baozhong; Xu, Zhonghua

    2011-07-01

    Bladder cancer is the ninth most common type of cancer, and its surgery is always followed by chemotherapy to prevent recurrence. Berberine is non-toxic to normal cells but has anti-cancer effects in many cancer cell lines. This study was aimed to determine whether berberine inhibits the cell proliferation and induces cell cycle arrest and apoptosis in BIU-87 and T24 bladder cancer cell line. The superficial bladder cancer cell line BIU-87 and invasive T24 bladder cancer cells were treated with different concentrations of berberine. MTT assay was used to determine the effects of berberine on the viability of these cells. The cell cycle arrest was detected through propidium iodide (PI) staining. The induction of apoptosis was determined through Annexin V-conjugated Alexa Fluor 488 (Alexa488) staining. Berberine inhibited the viability of BIU-87 and T24 cells in a dose- and time-dependent manner. It also promoted cell cycle arrest at G0/G1 in a dose-dependent manner and induced apoptosis. We observed that H-Ras and c-fos mRNA and protein expressionswere dose-dependently and time-dependently decreased by berberine treatment. Also, we investigated the cleaved caspase-3 and caspase-9 protein expressions increased in a dose-dependent manner. Berberine inhibits the cell proliferation and induces cell cycle arrest and apoptosis in BIU-87, bladder cancer cell line and T24, invasive bladder cancer cell line. Berberine can inhibit the oncogentic H-Ras and c-fos in T24 cells, and can induce the activation of the caspase-3 and caspase-9 apoptosis. Therefore, berberine has the potential to be a novel chemotherapy drug to treat the bladder cancer by suppressing tumor growth.

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

    SciTech Connect

    Ding, Li; Huang, Yong; Du, Qian; Dong, Feng; Zhao, Xiaomin; Zhang, Wenlong; Xu, Xingang; Tong, Dewen

    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

    SciTech Connect

    Chetty, Chandramu; Dontula, Ranadheer; Gujrati, Meena; Lakka, Sajani S.

    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. Apigenin inhibits pancreatic cancer cell proliferation through G2/M cell cycle arrest

    PubMed Central

    Ujiki, Michael B; Ding, Xian-Zhong; Salabat, M Reza; Bentrem, David J; Golkar, Laleh; Milam, Ben; Talamonti, Mark S; Bell, Richard H; Iwamura, Takeshi; Adrian, Thomas E

    2006-01-01

    Background Many chemotherapeutic agents have been used to treat pancreatic cancer without success. Apigenin, a naturally occurring flavonoid, has been shown to inhibit growth in some cancer cell lines but has not been studied in pancreatic cancer. We hypothesized that apigenin would inhibit pancreatic cancer cell growth in vitro. Results Apigenin caused both time- and concentration-dependent inhibition of DNA synthesis and cell proliferation in four pancreatic cancer cell lines. Apigenin induced G2/M phase cell cycle arrest. Apigenin reduced levels of cyclin A, cyclin B, phosphorylated forms of cdc2 and cdc25, which are all proteins required for G2/M transition. Conclusion Apigenin inhibits growth of pancreatic cancer cells through suppression of cyclin B-associated cdc2 activity and G2/M arrest, and may be a valuable drug for the treatment or prevention of pancreatic cancer. PMID:17196098

  10. Induction of apoptosis and cell-cycle arrest in human colon cancer cells by meclizine.

    PubMed

    Lin, Jiunn-Chang; Ho, Yuan-Soon; Lee, Jie-Jen; Liu, Chien-Liang; Yang, Tsen-Long; Wu, Chih-Hsiung

    2007-06-01

    Meclizine (MEC), a histamine H1 antagonist, is used for the treatment of motion sickness and vertigo. In this study, we demonstrate that MEC dose-dependently induced apoptosis in human colon cancer cell lines (COLO 205 and HT 29 cells). Results of a DNA ladder assay revealed that DNA ladders appeared with MEC treatment in COLO 205 cells at dosage of >50 microM. In addition, the total cell number decreased dose-dependently after treatment with MEC in COLO 205 and HT 29 cells. Using flow cytometry, the percentage of COLO 205 cells arrested at G0/G1 phase increased dose-dependently. Analysis of changes in cell-cycle arrest-associated proteins with Western blotting showed that p53 and p21 were upregulated after treatment with MEC. The kinase activities of cyclin-dependent kinase 2 (CDK2) and CDK4 were suppressed in MEC-treated cells. As for apoptosis, MEC may induce upregulation of p53 and downregulation of Bcl-2, thus causing the release of cytochrome C from mitochondria and the translocation of apoptosis-inducing factor (AIF) to the nucleus. This resulted in the activation of caspase 3, 8, and 9. Our results provide the molecular basis of MEC-induced apoptosis and cell-cycle arrest in human colon cancer cells. PMID:17222494

  11. Simvastatin induces cell cycle arrest and inhibits proliferation of bladder cancer cells via PPARγ signalling pathway

    PubMed Central

    Wang, Gang; Cao, Rui; Wang, Yongzhi; Qian, Guofeng; Dan, Han C.; Jiang, Wei; Ju, Lingao; Wu, Min; Xiao, Yu; Wang, Xinghuan

    2016-01-01

    Simvastatin is currently one of the most common drugs for old patients with hyperlipidemia, hypercholesterolemia and atherosclerotic diseases by reducing cholesterol level and anti-lipid properties. Importantly, simvastatin has also been reported to have anti-tumor effect, but the underlying mechanism is largely unknown. We collected several human bladder samples and performed microarray. Data analysis suggested bladder cancer (BCa) was significantly associated with fatty acid/lipid metabolism via PPAR signalling pathway. We observed simvastatin did not trigger BCa cell apoptosis, but reduced cell proliferation in a dose- and time-dependent manner, accompanied by PPARγ-activation. Moreover, flow cytometry analysis indicated that simvastatin induced cell cycle arrest at G0/G1 phase, suggested by downregulation of CDK4/6 and Cyclin D1. Furthermore, simvastatin suppressed BCa cell metastasis by inhibiting EMT and affecting AKT/GSK3β. More importantly, we found that the cell cycle arrest at G0/G1 phase and the alterations of CDK4/6 and Cyclin D1 triggered by simvastatin could be recovered by PPARγ-antagonist (GW9662), whereas the treatment of PPARα-antagonist (GW6471) shown no significant effects on the BCa cells. Taken together, our study for the first time revealed that simvastatin inhibited bladder cancer cell proliferation and induced cell cycle arrest at G1/G0 phase via PPARγ signalling pathway. PMID:27779188

  12. Cell Cycle Arrest by a Natural Product via G2/M Checkpoint

    PubMed Central

    2005-01-01

    CKBM is a natural product that exhibits a novel anti-tumor activity through the induction of cell cycle arrest and apoptosis. We have investigated its effects on cell cycle regulation using a gastric cancer cell line, AGS. The effects of CKBM on cell proliferation, cell cycle regulation and apoptosis were analyzed using BrdU (5-bromo-2'-deoxyuridine) cell proliferation assay and flow cytometric analysis, respectively. Specific cellular protein expressions were measured using Western blot analysis. Flow cytometric analysis indicated that CKBM induced G2/M cell cycle arrest and apoptosis, whereas differential protein expressions of p21, p53 and 14-3-3σ (stratifin) using Western blot analysis were enhanced. The differential expressions of p21, p53 and 14-3-3σ in AGS cancer cells after CKBM treatment may play critical roles in the G2/M cell cycle arrest that blocks cell proliferation and induces apoptosis. PMID:15968342

  13. Anti-hepatoma cells function of luteolin through inducing apoptosis and cell cycle arrest.

    PubMed

    Ding, Shixiong; Hu, Airong; Hu, Yaoren; Ma, Jianbo; Weng, Pengjian; Dai, Jinhua

    2014-04-01

    The aim of this study is to explore the apoptotic induction and cell cycle arrest function of luteolin on the liver cancer cells and the related mechanism. The liver cancer cell line SMMC-7721, BEL-7402, and normal liver cells HL-7702 were treated with different concentrations of luteolin. Cell proliferation ability was tested. Morphological changes of the apoptotic cells were observed under inverted fluorescence microscope after Hoechst33342 staining. We investigated the effect of luteolin on cell cycling and apoptosis with flow cytometry. The mitochondrial membrane potential changes were analyzed after JC-1 staining. Caspases-3 and Bcl-2 family proteins expression were analyzed by real-time PCR. Cell proliferation of SMMC-7721 and BEL-7402 were inhibited by luteolin, and the inhibition was dose-time-dependent. Luteolin could arrest the cells at G1/S stage, reduce mitochondrial membrane potential, and induce higher apoptosis rate and the typical apoptotic morphological changes of the liver carcinoma cells. Q-RT-PCR results also showed that luteolin increased Bax and caspase-3 expression significantly and upregulated Bcl-2 expression in a dose-dependent manner in liver carcinoma cells. However, the normal liver cells HL-7702 was almost not affected by luteolin treatment. Luteolin can inhibit SMMC-7721 and BEL-7402 cell proliferation in a time- and dose-dependent manner. And the mechanism maybe through arresting cell cycle at phase G1/S, enhancing Bax level, reducing anti-apoptotic protein Bcl-2 level, resulting in activating caspase-3 enzyme and decrease of mitochondrial membrane potential, and finally leading to cell apoptosis.

  14. G2 phase arrest prevents bristle progenitor self-renewal and synchronizes cell division with cell fate differentiation.

    PubMed

    Ayeni, Joseph O; Audibert, Agnès; Fichelson, Pierre; Srayko, Martin; Gho, Michel; Campbell, Shelagh D

    2016-04-01

    Developmentally regulated cell cycle arrest is a fundamental feature of neurogenesis, whose significance is poorly understood. During Drosophila sensory organ (SO) development, primary progenitor (pI) cells arrest in G2 phase for precisely defined periods. Upon re-entering the cell cycle in response to developmental signals, these G2-arrested precursor cells divide and generate specialized neuronal and non-neuronal cells. To study how G2 phase arrest affects SO lineage specification, we forced pI cells to divide prematurely. This produced SOs with normal neuronal lineages but supernumerary non-neuronal cell types because prematurely dividing pI cells generate a secondary pI cell that produces a complete SO and an external precursor cell that undergoes amplification divisions. pI cells are therefore able to undergo self-renewal before transit to a terminal mode of division. Regulation of G2 phase arrest thus serves a dual role in SO development: preventing progenitor self-renewal and synchronizing cell division with developmental signals. Cell cycle arrest in G2 phase temporally coordinates the precursor cell proliferation potential with terminal cell fate determination to ensure formation of organs with a normal set of sensory cells.

  15. Middle infrared radiation induces G2/M cell cycle arrest in A549 lung cancer cells.

    PubMed

    Chang, Hsin-Yi; Shih, Meng-Her; Huang, Hsuan-Cheng; Tsai, Shang-Ru; Juan, Hsueh-Fen; Lee, Si-Chen

    2013-01-01

    There were studies investigating the effects of broadband infrared radiation (IR) on cancer cell, while the influences of middle-infrared radiation (MIR) are still unknown. In this study, a MIR emitter with emission wavelength band in the 3-5 µm region was developed to irradiate A549 lung adenocarcinoma cells. It was found that MIR exposure inhibited cell proliferation and induced morphological changes by altering the cellular distribution of cytoskeletal components. Using quantitative PCR, we found that MIR promoted the expression levels of ATM (ataxia telangiectasia mutated), ATR (ataxia-telangiectasia and Rad3-related and Rad3-related), TP53 (tumor protein p53), p21 (CDKN1A, cyclin-dependent kinase inhibitor 1A) and GADD45 (growth arrest and DNA-damage inducible), but decreased the expression levels of cyclin B coding genes, CCNB1 and CCNB2, as well as CDK1 (Cyclin-dependent kinase 1). The reduction of protein expression levels of CDC25C, cyclin B1 and the phosphorylation of CDK1 at Thr-161 altogether suggest G(2)/M arrest occurred in A549 cells by MIR. DNA repair foci formation of DNA double-strand breaks (DSB) marker γ-H2AX and sensor 53BP1 was induced by MIR treatment, it implies the MIR induced G(2)/M cell cycle arrest resulted from DSB. This study illustrates a potential role for the use of MIR in lung cancer therapy by initiating DSB and blocking cell cycle progression.

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

    PubMed

    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

  17. VHL Induces Renal Cell Differentiation and Growth Arrest through Integration of Cell-Cell and Cell-Extracellular Matrix Signaling

    PubMed Central

    Davidowitz, Eliot J.; Schoenfeld, Alan R.; Burk, Robert D.

    2001-01-01

    Mutations in the von Hippel-Lindau (VHL) gene are involved in the family cancer syndrome for which it is named and the development of sporadic renal cell cancer (RCC). Reintroduction of VHL into RCC cells lacking functional VHL [VHL(−)] can suppress their growth in nude mice, but not under standard tissue culture conditions. To examine the hypothesis that the tumor suppressor function of VHL requires signaling through contact with extracellular matrix (ECM), 786-O VHL(−) RCC cells and isogenic sublines stably expressing VHL gene products [VHL(+)] were grown on ECMs. Cell-cell and cell-ECM signalings were required to elicit VHL-dependent differences in growth and differentiation. VHL(+) cells differentiated into organized epithelial sheets, whereas VHL(−) cells were branched and disorganized. VHL(+) cells grown to high density on collagen I underwent growth arrest, whereas VHL(−) cells continued to proliferate. Integrin levels were up-regulated in VHL(−) cells, and cell adhesion was down-regulated in VHL(+) cells during growth at high cell density. Hepatocyte nuclear factor 1α, a transcription factor and global activator of proximal tubule-specific genes in the nephron, was markedly up-regulated in VHL(+) cells grown at high cell density. These data indicate that VHL can induce renal cell differentiation and mediate growth arrest through integration of cell-cell and cell-ECM signals. PMID:11154273

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

    SciTech Connect

    Hu, Xiaolan; Zhang, Xianqi; Qiu, Shuifeng; Yu, Daihua; Lin, Shuxin

    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.

  19. Cell cycle arrest and activation of development in marine invertebrate deuterostomes.

    PubMed

    Costache, Vlad; McDougall, Alex; Dumollard, Rémi

    2014-08-01

    Like most metazoans, eggs of echinoderms and tunicates (marine deuterostomes, there is no data for the cephalochordates) arrest awaiting fertilization due to the activity of the Mos/MEK/MAPK cascade and are released from this cell cycle arrest by sperm-triggered Ca2+ signals. Invertebrate deuterostome eggs display mainly three distinct types of cell cycle arrest before fertilization mediated by potentially different cytostatic factors (CSF): one CSF causes arrest during meiotic metaphase I (MI-CSF in tunicates and some starfishes), another CSF likely causes arrest during meiotic metaphase II (amphioxus), and yet another form of CSF causes arrest to occur after meiotic exit during G1 of the first mitotic cycle (G1-CSF). In tunicates and echinoderms these different CSF activities have been shown to rely on the Mos//MAPK pathway for establishment and on Ca2+ signals for their inactivation. Despite these molecular similarities, release of MI-CSF arrest is caused by APC/C activation (to destroy cyclin B) whereas release from G1-CSF is caused by stimulating S phase and the synthesis of cyclins. Further research is needed to understand how both the Mos//MAPK cascade and Ca2+ achieve these tasks in different marine invertebrate deuterostomes. Another conserved feature of eggs is that protein synthesis of specific mRNAs is necessary to proceed through oocyte maturation and to maintain CSF-induced cell cycle arrest. Then activation of development at fertilization is accompanied by an increase in the rate of protein synthesis but the mechanisms involved are still largely unknown in most of the marine deuterostomes. How the sperm-triggered Ca2+ signals cause an increase in protein synthesis has been studied mainly in sea urchin eggs. Here we review these conserved features of eggs (arrest, activation and protein synthesis) focusing on the non-vertebrate deuterostomes. PMID:24721426

  20. Cell cycle arrest and activation of development in marine invertebrate deuterostomes.

    PubMed

    Costache, Vlad; McDougall, Alex; Dumollard, Rémi

    2014-08-01

    Like most metazoans, eggs of echinoderms and tunicates (marine deuterostomes, there is no data for the cephalochordates) arrest awaiting fertilization due to the activity of the Mos/MEK/MAPK cascade and are released from this cell cycle arrest by sperm-triggered Ca2+ signals. Invertebrate deuterostome eggs display mainly three distinct types of cell cycle arrest before fertilization mediated by potentially different cytostatic factors (CSF): one CSF causes arrest during meiotic metaphase I (MI-CSF in tunicates and some starfishes), another CSF likely causes arrest during meiotic metaphase II (amphioxus), and yet another form of CSF causes arrest to occur after meiotic exit during G1 of the first mitotic cycle (G1-CSF). In tunicates and echinoderms these different CSF activities have been shown to rely on the Mos//MAPK pathway for establishment and on Ca2+ signals for their inactivation. Despite these molecular similarities, release of MI-CSF arrest is caused by APC/C activation (to destroy cyclin B) whereas release from G1-CSF is caused by stimulating S phase and the synthesis of cyclins. Further research is needed to understand how both the Mos//MAPK cascade and Ca2+ achieve these tasks in different marine invertebrate deuterostomes. Another conserved feature of eggs is that protein synthesis of specific mRNAs is necessary to proceed through oocyte maturation and to maintain CSF-induced cell cycle arrest. Then activation of development at fertilization is accompanied by an increase in the rate of protein synthesis but the mechanisms involved are still largely unknown in most of the marine deuterostomes. How the sperm-triggered Ca2+ signals cause an increase in protein synthesis has been studied mainly in sea urchin eggs. Here we review these conserved features of eggs (arrest, activation and protein synthesis) focusing on the non-vertebrate deuterostomes.

  1. Metformin impairs growth of endometrial cancer cells via cell cycle arrest and concomitant autophagy and apoptosis

    PubMed Central

    2014-01-01

    Background Effective therapies for early endometrial cancer usually involve surgical excision and consequent infertility Therefore, new treatment approaches that preserve fertility should be developed. Metformin, a well-tolerated anti-diabetic drug, can inhibit cancer cell growth. However, the mechanism of metformin action is not well understood. Here we investigate the roles of autophagy and apoptosis in the anti-cancer effects of metformin on endometrial cancer cells. Methods Ishikawa endometrial cancer cells were treated with metformin. WST-8 assays, colony formation assays, flow cytometry, caspase luminescence measurement, immunofluorescence, and western blots were used to assess the effects of metformin on cell viability, proliferation, cell cycle progression, apoptosis, and autophagy. Results Metformin-treated cells exhibited significantly lower viability and proliferation and significantly more cell cycle arrest in G1 and G2/M than control cells. These cells also exhibited significantly more apoptosis via both intrinsic and extrinsic pathways. In addition, metformin treatment induced autophagy. Inhibition of autophagy, either by Beclin1 knockdown or by 3-methyladenine-mediated inhibition of caspase-3/7, suppressed the anti-proliferative effects of metformin on endometrial cancer cells. These findings indicate that the anti-proliferative effects and apoptosis caused by metformin are partially or completely dependent on autophagy. Conclusions We showed that metformin suppresses endometrial cancer cell growth via cell cycle arrest and concomitant autophagy and apoptosis. PMID:24966801

  2. Platinum-zoledronate complex blocks gastric cancer cell proliferation by inducing cell cycle arrest and apoptosis.

    PubMed

    Yang, Hui; Qiu, Ling; Zhang, Li; Lv, Gaochao; Li, Ke; Yu, Huixin; Xie, Minhao; Lin, Jianguo

    2016-08-01

    A series of novel dinuclear platinum complexes based on the bisphosphonate ligands have been synthesized and characterized in our recent study. For the purpose of discovering the pharmacology and action mechanisms of this kind of compounds, the most potent compound [Pt(en)]2ZL was selected for systematic investigation. In the present study, the inhibition effect on the human gastric cancer cell lines SGC7901 and action mechanism of [Pt(en)]2ZL were investigated. The traditional 3-[4,5-dimethyl-2-thiazolyl]-2,5-diphenyl-2-tetrazolium bromide (MTT) assay and colony formation assay were carried out to study the effect of [Pt(en)]2ZL on the cell viability and proliferation capacity, respectively. The senescence-associated β-galactosidase staining and immunofluorescence staining were also performed to assess the cell senescence and microtubule polymerization. Fluorescence staining and flow cytometry (FCM) were used to monitor the cell cycle distribution and apoptosis, and Western blot analysis was applied to examine the expression of several apoptosis-related proteins. The results demonstrated that [Pt(en)]2ZL exhibited remarkable cytotoxicity and anti-proliferative effects on the SGC7901 cells in a dose- and time-dependent manner, and it also induced cell senescence and abnormal microtubule assembly. The cell apoptosis and cell cycle arrest induced by [Pt(en)]2ZL were also observed with the fluorescence staining and FCM. The expressions of cell cycle regulators (p53, p21, cyclin D1, cyclin E, and cyclin-dependent kinase (CDK)2) and apoptosis-related proteins (Bcl-2, Bax, caspase-3, poly ADP ribose polymerase (PARP), and survivin) were regulated by the treatment of [Pt(en)]2ZL, resulting in the cell cycle arrest and apoptosis. Therefore, [Pt(en)]2ZL exerted anti-tumor effect on the gastric cancer via inducing cell cycle arrest at G1/S phase and apoptosis. PMID:26891667

  3. Induction of cell cycle arrest in prostate cancer cells by the dietary compound isoliquiritigenin.

    PubMed

    Lee, Yeo Myeong; Lim, Do Young; Choi, Hyun Ju; Jung, Jae In; Chung, Won-Yoon; Park, Jung Han Yoon

    2009-02-01

    Isoliquiritigenin (ISL), a flavonoid chalcone that is present in licorice, shallot, and bean sprouts, is known to have antitumorigenic activities. The present study examined whether ISL alters prostate cancer cell cycle progression. DU145 human and MatLyLu (MLL) rat prostate cancer cells were cultured with various concentrations of ISL. In both DU145 and MLL cells treated with ISL, the percentage of cells in the G1 phase increased, and the incorporation of [(3)H]thymidine decreased. ISL decreased the protein levels of cyclin D1, cyclin E, and cyclin-dependent kinase (CDK) 4, whereas cyclin A and CDK2 expressions were unaltered in cells treated with ISL. The expression of the CDK inhibitor p27(KIP1) was increased in cells treated with 20 micromol/L ISL. In addition, treatment of cells with 20 micromol/L ISL for 24 hours led to G2/M cell cycle arrest. Cell division control (CDC) 2 protein levels remained unchanged. The protein levels of phospho-CDC2 (Tyr15) and cyclin B1 were increased, and the CDC25C level was decreased by ISL dose-dependently. We demonstrate that ISL promotes cell cycle arrest in DU145 and MLL cells, thereby providing insights into the mechanisms underlying its antitumorigenic activities.

  4. Induction of cell cycle arrest in prostate cancer cells by the dietary compound isoliquiritigenin.

    PubMed

    Lee, Yeo Myeong; Lim, Do Young; Choi, Hyun Ju; Jung, Jae In; Chung, Won-Yoon; Park, Jung Han Yoon

    2009-02-01

    Isoliquiritigenin (ISL), a flavonoid chalcone that is present in licorice, shallot, and bean sprouts, is known to have antitumorigenic activities. The present study examined whether ISL alters prostate cancer cell cycle progression. DU145 human and MatLyLu (MLL) rat prostate cancer cells were cultured with various concentrations of ISL. In both DU145 and MLL cells treated with ISL, the percentage of cells in the G1 phase increased, and the incorporation of [(3)H]thymidine decreased. ISL decreased the protein levels of cyclin D1, cyclin E, and cyclin-dependent kinase (CDK) 4, whereas cyclin A and CDK2 expressions were unaltered in cells treated with ISL. The expression of the CDK inhibitor p27(KIP1) was increased in cells treated with 20 micromol/L ISL. In addition, treatment of cells with 20 micromol/L ISL for 24 hours led to G2/M cell cycle arrest. Cell division control (CDC) 2 protein levels remained unchanged. The protein levels of phospho-CDC2 (Tyr15) and cyclin B1 were increased, and the CDC25C level was decreased by ISL dose-dependently. We demonstrate that ISL promotes cell cycle arrest in DU145 and MLL cells, thereby providing insights into the mechanisms underlying its antitumorigenic activities. PMID:19298190

  5. Novel antiproliferative flavonoids induce cell cycle arrest in human prostate cancer cell lines.

    PubMed

    Haddad, A Q; Venkateswaran, V; Viswanathan, L; Teahan, S J; Fleshner, N E; Klotz, L H

    2006-01-01

    Epidemiologic studies have demonstrated an inverse association between flavonoid intake and prostate cancer (PCa) risk. The East Asian diet is very high in flavonoids and, correspondingly, men in China and Japan have the lowest incidence of PCa worldwide. There are thousands of different naturally occurring and synthetic flavonoids. However, only a few have been studied in PCa. Our aim was to identify novel flavonoids with antiproliferative effect in PCa cell lines, as well as determine their effects on cell cycle. We have screened a representative subgroup of 26 flavonoids for antiproliferative effect on the human PCa (LNCaP and PC3), breast cancer (MCF-7), and normal prostate stromal cell lines (PrSC). Using a fluorescence-based cell proliferation assay (Cyquant), we have identified five flavonoids, including the novel compounds 2,2'-dihydroxychalcone and fisetin, with antiproliferative and cell cycle arresting properties in human PCa in vitro. Most of the flavonoids tested exerted antiproliferative effect at lower doses in the PCa cell lines compared to the non-PCa cells. Flow cytometry was used as a means to determine the effects on cell cycle. PC3 cells were arrested in G2/M phase by flavonoids. LNCaP cells demonstrated different cell cycle profiles. Further studies are warranted to determine the molecular mechanism of action of 2,2'-DHC and fisetin in PCa, and to establish their effectiveness in vivo.

  6. A synthetic circuit for selectively arresting daughter cells to create aging populations.

    PubMed

    Afonso, Bruno; Silver, Pamela A; Ajo-Franklin, Caroline M

    2010-05-01

    The ability to engineer genetic programs governing cell fate will permit new safeguards for engineered organisms and will further the biological understanding of differentiation and aging. Here, we have designed, built and implemented a genetic device in the budding yeast Saccharomyces cerevisiae that controls cell-cycle progression selectively in daughter cells. The synthetic device was built in a modular fashion by combining timing elements that are coupled to the cell cycle, i.e. cell-cycle specific promoters and protein degradation domains, and an enzymatic domain which conditionally confers cell arrest. Thus, in the presence of a drug, the device is designed to arrest growth of only newly-divided daughter cells in the population. Indeed, while the engineered cells grow normally in the absence of drug, with the drug the engineered cells display reduced, linear growth on the population level. Fluorescence microscopy of single cells shows that the device induces cell arrest exclusively in daughter cells and radically shifts the age distribution of the resulting population towards older cells. This device, termed the 'daughter arrester', provides a blueprint for more advanced devices that mimic developmental processes by having control over cell growth and death.

  7. Bcl-2 accelerates retinoic acid-induced growth arrest and recovery in human gastric cancer cells.

    PubMed Central

    Chou, H K; Chen, S L; Hsu, C T; Chao, Y C; Tsao, Y P

    2000-01-01

    The role of Bcl-2 as an anti-apoptotic protein has been well documented. In the present work, we present evidence that Bcl-2 may also be involved in cell growth regulation. SC-M1 is an unique cell line which responds to retinoic acid (RA) treatment with reversible growth arrest [Shyu, Jiang, Huang, Chang, Wu, Roffler and Yeh (1995) Eur. J. Cancer 31, 237-243]. In this study, when treated with RA, SC-M1/Bcl2 cells, which were generated by transfecting SC-M1 cells with bcl-2 DNA, were growth-arrested two days earlier than SC-M1/neo cells, which were generated by transfecting SC-M1 cells with vector DNA. This indicates that Bcl-2 accelerates RA-induced growth arrest. In addition to the accelerated growth arrest, RA-treated SC-M1/Bcl2 cells also recovered from growth arrest two days faster than SC-M1/neo cells after the removal of RA. Previously, we had identified the cyclin-dependent kinase inhibitor p21((WAF1/CIP1)) (p21) as a mediator of RA-induced growth arrest [Tsao, Li, Kuo, Liu and Chen (1996) Biochem. J. 317, 707-711]. In a search for the mechanism by which Bcl-2 affects growth regulation, we found that p21 gene expression was more prominent in SC-M1/Bcl2 cells than in SC-M1/neo cells in the presence of RA, but when RA was removed, p21 gene expression levels in SC-M1/Bcl2 cells were also reduced earlier than in SC-M1/neo cells. The present report is the first to show that Bcl-2 accelerates not only growth arrest but also recovery from growth arrest. Moreover, the close correlation between the effect of Bcl-2 on both RA-induced growth arrest and RA-induced p21 gene expression suggests the possibility that Bcl-2 affects cell growth through the mechanism of p21. PMID:10816444

  8. Chinese medicinal herb, Acanthopanax gracilistylus, extract induces cell cycle arrest of human tumor cells in vitro.

    PubMed

    Shan, B E; Zeki, K; Sugiura, T; Yoshida, Y; Yamashita, U

    2000-04-01

    We investigated the effect of a Chinese medicinal herb, Acanthopanax gracilistylus (AG), extract (E) on the growth of human tumor cell lines in vitro. AGE markedly inhibited the proliferation of several tumor cell lines such as MT-2, Raji, HL-60, TMK-1 and HSC-2. The activity was associated with a protein of 60 kDa, which was purified by gel-filtration chromatography. Cell viability analyses indicated that the treatment with AGE inhibits cell proliferation, but does not induce cell death. The mechanism of AGE-induced inhibition of tumor cell growth involves arrest of the cell cycle at the G(0) / G(1) stage without a direct cytotoxic effect. The cell cycle arrest induced by AGE was accompanied by a decrease of phosphorylated retinoblastoma (Rb) protein. Furthermore, cyclin-dependent kinases 2 and 4 (Cdk2 and Cdk4), which are involved in the phosphorylation of Rb, were also decreased. These results suggest that AGE inhibits tumor cell growth by affecting phosphorylated Rb proteins and Cdks. PMID:10804285

  9. Diosgenin induces G2/M cell cycle arrest and apoptosis in human hepatocellular carcinoma cells.

    PubMed

    Li, Yongjian; Wang, Xiaorong; Cheng, Silu; Du, Juan; Deng, Zhengting; Zhang, Yani; Liu, Qun; Gao, Jingdong; Cheng, Binbin; Ling, Changquan

    2015-02-01

    Diosgenin is a major compound of Dioscoreaceae plants such as yam, which is used as a drug in Traditional Chinese Medicine, and a common vegetable worldwide. The anticancer effect of diosgenin has been reported in various tumor cells, including leukemia, gastric, colorectal, and breast cancer. However, the activity of diosgenin on hepatocellular carcinoma (HCC) and the underlying mechanism have not been completely investigated. Therefore, we investigated the efficacy and associated mechanisms of diosgenin in HCC cells. Flow cytometric analysis was performed to determine the presence of cell cycle arrest and apopotic cells. Diosgenin significantly inhibited the growth of Bel-7402, SMMC-7721 and HepG2 HCC cells in a concentration-dependent manner. Diosgenin treatment for 24 h induced G2/M cell cycle arrest and apoptosis of hepatoma cells. Diosgenin inhibited Akt phosphorylation and upregulated p21 and p27 expression, but did not alter the expression of p53, suggesting diosgenin-induced upregulation of p21 and p57 is p53-independent in HCC cells. Diosgenin induced HCC cell apoptosis by activating caspase cascades -3, -8 and -9. However, diosgenin did not affect Bcl-2 and Bax levels. In conclusion, results of the present study suggest that diosgenin may be an active anti-HCC agent obtained from natural plants and provide new insights in understanding the mechanisms of diosgenin. PMID:25434486

  10. PVM/MA-shelled selol nanocapsules promote cell cycle arrest in A549 lung adenocarcinoma cells

    PubMed Central

    2014-01-01

    Background Selol is an oily mixture of selenitetriacylglycerides that was obtained as a semi-synthetic compound containing selenite. Selol is effective against cancerous cells and less toxic to normal cells compared with inorganic forms of selenite. However, Selol’s hydrophobicity hinders its administration in vivo. Therefore, the present study aimed to produce a formulation of Selol nanocapsules (SPN) and to test its effectiveness against pulmonary adenocarcinoma cells (A549). Results Nanocapsules were produced through an interfacial nanoprecipitation method. The polymer shell was composed of poly(methyl vinyl ether-co-maleic anhydride) (PVM/MA) copolymer. The obtained nanocapsules were monodisperse and stable. Both free Selol (S) and SPN reduced the viability of A549 cells, whereas S induced a greater reduction in non-tumor cell viability than SPN. The suppressor effect of SPN was primarily associated to the G2/M arrest of the cell cycle, as was corroborated by the down-regulations of the CCNB1 and CDC25C genes. Apoptosis and necrosis were induced by Selol in a discrete percentage of A549 cells. SPN also increased the production of reactive oxygen species, leading to oxidative cellular damage and to the overexpression of the GPX1, CYP1A1, BAX and BCL2 genes. Conclusions This study presents a stable formulation of PVM/MA-shelled Selol nanocapsules and provides the first demonstration that Selol promotes G2/M arrest in cancerous cells. PMID:25149827

  11. HPV-18 transformed cells fail to arrest in G1 in response to quercetin treatment.

    PubMed

    Beniston, R G; Campo, M S

    2005-05-01

    Previous work with primary human keratinocytes demonstrated that quercetin, a potent mutagen found in high levels in bracken fern (Pteridium aquilinum), arrested cells in G1 with concomitant elevation of the cyclin-dependent kinase inhibitor (cdki) p27Kip1. Expression of the human papillomavirus type 16 (HPV-16) E6 and E7 oncoproteins, under transcriptional control of a heterologous promoter, in transformed keratinocytes failed to abrogate this arrest [Beniston, R., Campo, M.S., 2003. Quercetin elevates p27Kip1 and arrests both primary and HPV-16 E6/E7 transformed human keratinocytes in G1. Oncogene 22, 5504-5514]. Given the link between papillomavirus infection, bracken fern in the diet and cancer of the oesophagus in humans, we wished to investigate further whether cells transformed by the whole genome of HPV-16 or HPV-18, with E6 and E7 under the transcriptional control of their respective homologous promoters, would be similarly arrested in G1 by quercetin. In agreement with earlier work, quercetin arrested HPV-16 transformed cells in G1 with an increase in the cyclin-dependent kinase inhibitor p27Kip1. However, HPV-18 transformed cells did not arrest after quercetin treatment. The failure of HPV-18 transformed cells to arrest in G1 was linked to the up-regulation of the HPV-18 long control region (LCR) by quercetin, maintaining high expression of the viral transforming proteins. Transcriptional up-regulation of the HPV-18 LCR was mediated by a "quercetin responsive element" homologous to the one identified previously in the bovine papillomavirus type 4 (BPV-4) LCR.

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

    SciTech Connect

    Tian, Junqiang; Doi, Hiroshi; Saar, Matthias; Santos, Jennifer; Li, Xuejun; Peehl, Donna M.; Knox, Susan J.

    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.

  13. The Oxygen Rich Postnatal Environment Induces Cardiomyocyte Cell Cycle Arrest Through DNA Damage Response

    PubMed Central

    Puente, Bao N.; Kimura, Wataru; Muralidhar, Shalini A.; Moon, Jesung; Amatruda, James F.; Phelps, Kate L.; Grinsfelder, David; Rothermel, Beverly A.; Chen, Rui; Garcia, Joseph A.; Santos, Celio X.; Thet, SuWannee; Mori, Eiichiro; Kinter, Michael T.; Rindler, Paul M.; Zacchigna, Serena; Mukherjee, Shibani; Chen, David J.; Mahmoud, Ahmed I.; Giacca, Mauro; Rabinovitch, Peter S.; Aroumougame, Asaithamby; Shah, Ajay M.; Szweda, Luke I.; Sadek, Hesham A.

    2014-01-01

    Summary 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 DNA damage response (DDR) markers significantly increase in the heart during the first postnatal week. Intriguingly, postnatal hypoxemia, ROS scavenging, or inhibition of DDR all prolong the postnatal proliferative window of cardiomyocytes, while hyperoxemia and ROS generators shorten it. These findings uncover a previously unrecognized protective mechanism that mediates cardiomyocyte cell cycle arrest in exchange for utilization of oxygen dependent aerobic metabolism. Reduction of mitochondrial-dependent oxidative stress should be important component of cardiomyocyte proliferation-based therapeutic approaches. PMID:24766806

  14. Cell cycle age dependence for radiation-induced G/sub 2/ arrest: evidence for time-dependent repair

    SciTech Connect

    Rowley, R.

    1985-09-01

    Exponentially growing eucaryotic cells, irradiated in interphase, are delayed in progression to mitosis chiefly by arrest in G/sub 2/. The sensitivity of Chinese hamster ovary cells to G/sub 2/ arrest induction by X rays increases through the cell cycle, up to the X-ray transition point (TP) in G/sub 2/. This age response can be explained by cell cycle age-dependent changes in susceptibility of the target(s) for G/sub 2/ arrest and/or by changes in capability for postirradiation recovery from G/sub 2/ arrest damage. Discrimination between sensitivity changes and repair phenomena is possible only if the level of G/sub 2/ arrest-causing damage sustained by a cell at the time of irradiation and the level ultimately expressed as arrest can be determined. The ability of caffeine to ameliorate radiation-induced G/sub 2/ arrest, while inhibiting repair of G/sub 2/ arrest-causing damage makes such an analysis possible. In the presence of caffeine, progression of irradiated cells was relatively unperturbed, but on caffeine removal, G/sub 2/ arrest was expressed. The duration of G/sub 2/ arrest was independent of the length of the prior caffeine exposure. This finding indicates that the target for G/sub 2/ arrest induction is present throughout the cell cycle and that the level of G/sub 2/ arrest damage incurred is initially constant for all cell cycle phases. The data are consistent with the existence of a time-dependent recovery mechanism to explain the age dependence for radiation induction of G/sub 2/ arrest.

  15. Glucose restriction induces transient G2 cell cycle arrest extending cellular chronological lifespan.

    PubMed

    Masuda, Fumie; Ishii, Mahiro; Mori, Ayaka; Uehara, Lisa; Yanagida, Mitsuhiro; Takeda, Kojiro; Saitoh, Shigeaki

    2016-01-01

    While glucose is the fundamental source of energy in most eukaryotes, it is not always abundantly available in natural environments, including within the human body. Eukaryotic cells are therefore thought to possess adaptive mechanisms to survive glucose-limited conditions, which remain unclear. Here, we report a novel mechanism regulating cell cycle progression in response to abrupt changes in extracellular glucose concentration. Upon reduction of glucose in the medium, wild-type fission yeast cells undergo transient arrest specifically at G2 phase. This cell cycle arrest is dependent on the Wee1 tyrosine kinase inhibiting the key cell cycle regulator, CDK1/Cdc2. Mutant cells lacking Wee1 are not arrested at G2 upon glucose limitation and lose viability faster than the wild-type cells under glucose-depleted quiescent conditions, suggesting that this cell cycle arrest is required for extension of chronological lifespan. Our findings indicate the presence of a novel cell cycle checkpoint monitoring glucose availability, which may be a good molecular target for cancer therapy. PMID:26804466

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

    PubMed Central

    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 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(NO3)2-treated cells, indicative of membrane 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

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

    PubMed

    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 < 0.05) increase of necrotic cell death in Pb(NO₃)₂-treated cells, indicative of membrane 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

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

    PubMed

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

    2015-12-22

    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 < 0.05) increase of necrotic cell death in Pb(NO₃)₂-treated cells, indicative of membrane 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

  19. Polydatin inhibits growth of lung cancer cells by inducing apoptosis and causing cell cycle arrest.

    PubMed

    Zhang, Yusong; Zhuang, Zhixiang; Meng, Qinghui; Jiao, Yang; Xu, Jiaying; Fan, Saijun

    2014-01-01

    Polydatin (PD), a small natural compound from Polygonum cuspidatum, has a number of biological functions. However, the anticancer activity of PD has been poorly investigated. In the present study, thiazolyl blue tetrazolium bromide assay was used to evaluate the inhibitory effect of PD on cell growth. Cell cycle distribution and apoptosis were investigated by flow cytometry. In addition, the expression of several proteins associated with apoptosis and cell cycle were analyzed by western blot analysis. The results demonstrated that PD significantly inhibits the proliferation of A549 and NCI-H1975 lung cancer cell lines and causes dose-dependent apoptosis. Cell cycle analysis revealed that PD induces S phase cell cycle arrest. Western blot analysis showed that the expression of Bcl-2 decreased as that of Bax increased, and the expression of cyclin D1 was also suppressed. The results suggest that PD has potential therapeutic applications in the treatment of lung cancer. PMID:24348867

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

    PubMed

    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

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

    PubMed

    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.

  2. Altered Cell Cycle Arrest by Multifunctional Drug-Loaded Enzymatically-Triggered Nanoparticles.

    PubMed

    Huang, Can; Sun, Ying; Shen, Ming; Zhang, Xiangyu; Gao, Pei; Duan, Yourong

    2016-01-20

    cRGD-targeting matrix metalloproteinase (MMP)-sensitive nanoparticles [PLGA-PEG1K-cRGD/PLGA-peptide-PEG5K (NPs-cRGD)] were successfully developed. Au-Pt(IV) nanoparticles, PTX, and ADR were encapsulated into NPs-RGD separately. The effects of the drug-loaded nanoparticles on the cell cycle were investigated. Here, we showed that higher cytotoxicity of drug-loaded nanoparticles was related to the cell cycle arrest, compared to that of free drugs. The NPs-cRGD studied here did not disrupt cell cycle progression. The cell cycle of Au-Pt(IV)@NPs-cRGD showed a main S phase arrest in all phases of the cell cycle phase, especially in G0/G1 phase. PTX@NPs-cRGD and ADR@NPs-cRGD showed a higher ratio of G2/M and S phase arrest than the free drugs, respectively. Cells in G0/G1 and S phases of the cell cycle had a higher uptake ratio of NPs-cRGD. A nutrient deprivation or an increase in the requirement of nutrients in tumor cells could promote the uptake of nanoparticles from the microenvironments. In vivo, NPs-cRGD could efficiently accumulate at tumor sites. The inhibition of tumor growth coupled with cell cycle arrest is in line with that in vitro. On the basis of our results, we propose that future studies on nanoparticle action mechanism should consider the cell cycle, which could be different from free drugs. Understanding the actions of cell cycle arrest could affect the application of nanomedicine in the clinic.

  3. Oscillation of APC/C activity during cell cycle arrest promotes centrosome amplification

    PubMed Central

    Prosser, Suzanna L.; Samant, Mugdha D.; Baxter, Joanne E.; Morrison, Ciaran G.; Fry, Andrew M.

    2014-01-01

    Centrosome duplication is licensed by the disengagement, or ‘uncoupling’, of centrioles during late mitosis. However, arrest of cells in G2 can trigger premature centriole disengagement. Here, we show that premature disengagement results from untimely activation of the APC/C leading to securin degradation and release of active separase. APC/C activation during G2 arrest is dependent on Plk1-mediated degradation of the APC/C inhibitor, Emi1, but Plk1 also has a second APC/C-independent role in promoting disengagement. Importantly, APC/C and Plk1 activity also stimulate centriole disengagement in response to hydroxyurea or DNA damage-induced cell cycle arrest and this leads to centrosome amplification. However, the re-duplication of disengaged centrioles is dependent on Cdk2 activity and Cdk2 activation coincides with a subsequent inactivation of the APC/C and re-accumulation of cyclin A. Release from these arrests leads to mitotic entry but, due to the presence of disengaged and/or amplified centrosomes, formation of abnormal mitotic spindles that lead to chromosome missegregation. Thus, oscillation of APC/C activity during cell cycle arrest promotes both centrosome amplification and genome instability. PMID:22956538

  4. Cell cycle arrest mediated by the MEK/mitogen-activated protein kinase pathway

    PubMed Central

    Pumiglia, Kevin M.; Decker, Stuart J.

    1997-01-01

    The mitogen-activated protein kinase (MAPK) cascade plays a crucial role in the transduction of extracellular signals into responses governing growth and differentiation. The effects of a specific inhibitor of the MAPK kinase (MEK)/MAPK pathway (PD98059) on nerve growth factor (NGF)-induced growth arrest and inhibition of cell cycle-dependent kinases (CDKs) have been examined. Treatment of NIH 3T3 cells expressing TRKA with PD98059 dramatically reversed the complete inhibition of growth of these cells caused by NGF. PD98059 also blocked the ability of NGF to inhibit the activities of CDK4 and CDK2, while partially preventing NGF induction of p21Cip1/WAF1. To independently evaluate the involvement of the MEK/MAPK pathway in growth arrest, an inducible activated form of the Raf-1 protooncogene (ΔRAF-1:ER) was expressed in these cells. Activation of ΔRAF-1:ER resulted in a prolonged increase in MAPK activity and growth arrest of these cells, with concomitant induction of p21Cip1/WAF1 and inhibition of CDK2 activity. These effects of ΔRAF-1:ER activation were all reversed by treatment of cells with PD98059. These data indicate that in addition to functioning as a positive effector of growth, stimulation of the MEK/MAPK pathway can result in an inhibition of CDK activity and cell cycle arrest. PMID:9012803

  5. Monoclonal antibody against dnmt1 arrests the cell division of xenopus early-stage embryos.

    PubMed

    Hashimoto, Hideharu; Suetake, Isao; Tajima, Shoji

    2003-06-10

    DNA methylation plays a crucial role in embryogenesis, and Dnmt1 is known to be a key enzyme in the maintenance of DNA methylation. Dnmt1 is highly accumulated in mature oocytes and eggs. To analyze the function of the maternally accumulated Dnmt1, we injected monoclonal antibodies that specifically recognize the amino terminus of Xenopus Dnmt1 into Xenopus laevis embryos. The monoclonal antibodies inhibited the cell division of the embryos before the midblastula transition. Monoclonal antibody neither inhibited DNA methylation activity of Dnmt1 in vitro nor affected its stability in embryos. In addition, injection of alpha-amanitin, an inhibitor of transcription, did not rescue the cell division arrest. The results suggest that the inhibition of cell division by monoclonal antibodies was due neither to the direct inhibition of DNA methylation activity of Dnmt1 nor to aberrant transcription before the midblastula transition. The morphology of chromatin of the arrested cells showed that the cell cycle was arrested at interphase. This was supported by the biochemical analysis in which the arrested cells demonstrated low histone H1 kinase activity, which indicated that the cells had not entered M phase. Dnmt1 may have an important function other than DNA methylation activity for early embryogenesis in Xenopus laevis. PMID:12749854

  6. A synthetic circuit for selectively arresting daughter cells to create aging populations

    PubMed Central

    Afonso, Bruno; Silver, Pamela A.; Ajo-Franklin, Caroline M.

    2010-01-01

    The ability to engineer genetic programs governing cell fate will permit new safeguards for engineered organisms and will further the biological understanding of differentiation and aging. Here, we have designed, built and implemented a genetic device in the budding yeast Saccharomyces cerevisiae that controls cell-cycle progression selectively in daughter cells. The synthetic device was built in a modular fashion by combining timing elements that are coupled to the cell cycle, i.e. cell-cycle specific promoters and protein degradation domains, and an enzymatic domain which conditionally confers cell arrest. Thus, in the presence of a drug, the device is designed to arrest growth of only newly-divided daughter cells in the population. Indeed, while the engineered cells grow normally in the absence of drug, with the drug the engineered cells display reduced, linear growth on the population level. Fluorescence microscopy of single cells shows that the device induces cell arrest exclusively in daughter cells and radically shifts the age distribution of the resulting population towards older cells. This device, termed the ‘daughter arrester’, provides a blueprint for more advanced devices that mimic developmental processes by having control over cell growth and death. PMID:20150416

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

    NASA Astrophysics Data System (ADS)

    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.

  8. Vincristine induces cell cycle arrest and apoptosis in SH-SY5Y human neuroblastoma cells.

    PubMed

    Tu, Yue; Cheng, Shixiang; Zhang, Sai; Sun, Hongtao; Xu, Zhongwei

    2013-01-01

    Neuroblastoma is a common childhood tumor. Vincristine (VCR), an alkaloid extracted from Catharanthus roseus, is commonly used in combination chemotherapy. However, the mechanisms of VCR-induced neuroblastoma cell death are not clear. The aim of this study was to investigate the impact of VCR on mitosis and apoptosis of SH-SY5Y neuroblastoma cells and the underlying mechanisms. SH-SY5Y cells were treated with increasing VCR doses for different time points. Cell proliferation was detected using the MTT assay. Mitotic rate was quantified by immunofluorescence. Cell cycle and apoptosis were analyzed by flow cytometry. The mRNA and protein expression of caspase-3 and -9 (apoptotic factors), as well as cyclin B and D (cell cycle factors), was evaluated by real-time (RT)-PCR and western blot analysis, respectively. VCR inhibited SH-SY5Y cell proliferation in a time- and dose-dependent manner (P<0.05). The IC50 of VCR in SH-SY5Y cells was determined as 0.1 µM. VCR at 0.1 µM induced mitotic arrest and apoptosis, promoted the expression of caspase-3 and -9 and cyclin B, while decreasing the expression of cyclin D at 6, 12, 18 and 24 h. Except for the mRNA expression of cyclin D at 6 h, these changes were significant at both the mRNA and protein levels (P<0.05). VCR induces mitotic arrest of SH-SY5Y cells by regulating cyclin B and D. It further induces apoptosis in these cells through the activation of caspase-3 and -9. This study provides fundamental evidence for the application of VCR in neuroblastoma chemotherapy.

  9. Vitisin A inhibits adipocyte differentiation through cell cycle arrest in 3T3-L1 cells

    SciTech Connect

    Kim, Soon-hee; Park, Hee-Sook; Lee, Myoung-su; Cho, Yong-Jin; Kim, Young-Sup; Hwang, Jin-Taek; Sung, Mi Jeong; Kim, Myung Sunny; Kwon, Dae Young

    2008-07-18

    Inhibition of adipocyte differentiation is one approach among the anti-obesity strategies. This study demonstrates that vitisin A, a resveratrol tetramer, inhibits adipocyte differentiation most effectively of 18 stilbenes tested. Fat accumulation and PPAR{gamma} expression were decreased by vitisin A in a dose-dependent manner. Vitisin A significantly inhibited preadipocyte proliferation and consequent differentiation within the first 2 days of treatment, indicating that the anti-adipogenic effect of vitisin A was derived from anti-proliferation. Based on cell cycle analysis, vitisin A blocked the cell cycle at the G1-S phase transition, causing cells to remain in the preadipocyte state. Vitisin A increased p21 expression, while the Rb phosphorylation level was reduced. Therefore, vitisin A seems to induce G1 arrest through p21- and consequent Rb-dependent suppression of transcription. On the other hand, ERK and Akt signaling pathways were not involved in the anti-mitotic regulation by vitisin A. Taken together, these results suggest that vitisin A inhibits adipocyte differentiation through preadipocyte cell cycle arrest.

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

    SciTech Connect

    Xu, Hongliang; Wang, Zhaoxia; Jin, Suqin; Hao, Hongjun; Zheng, Lemin; Zhou, Boda; Zhang, Wei; Lv, He; Yuan, Yun

    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.

  11. Cell-cycle arrest and acute kidney injury: the light and the dark sides

    PubMed Central

    Kellum, John A.; Chawla, Lakhmir S.

    2016-01-01

    Acute kidney injury (AKI) is a common consequence of systemic illness or injury and it complicates several forms of major surgery. Two major difficulties have hampered progress in AKI research and clinical management. AKI is difficult to detect early and its pathogenesis is still poorly understood. We recently reported results from multi-center studies where two urinary markers of cell-cycle arrest, tissue inhibitor of metalloproteinases-2 (TIMP-2) and insulin-like growth factor-binding protein 7 (IGFBP7) were validated for development of AKI well ahead of clinical manifestations—azotemia and oliguria. Cell-cycle arrest is known to be involved in the pathogenesis of AKI and this ‘dark side’ may also involve progression to chronic kidney disease. However, cell-cycle arrest has a ‘light side’ as well, since this mechanism can protect cells from the disastrous consequences of entering cell division with damaged DNA or insufficient bioenergetic resources during injury or stress. Whether we can use the light side to help prevent AKI remains to be seen, but there is already evidence that cell-cycle arrest biomarkers are indicators of both sides of this complex physiology. PMID:26044835

  12. Using Drosophila Larval Imaginal Discs to Study Low-Dose Radiation-Induced Cell Cycle Arrest

    PubMed Central

    Yan, Shian-Jang; Li, Willis X.

    2012-01-01

    Under genotoxic stress, activation of cell cycle checkpoint responses leads to cell cycle arrest, which allows cells to repair DNA damage before continuing to cycle. Drosophila larval epithelial sacs, called imaginal discs, are an excellent in vivo model system for studying radiation-induced cell cycle arrest. Larval imaginal discs go into cell cycle arrest after being subjected to low-dose irradiation, are subject to easy genetic manipulation, are not crucial for survival of the organism, and can be dissected easily for further molecular or cellular analysis. In this chapter, we describe methods for assessing low-dose irradiation-induced cell cycle arrest. Mitotic cells are identified by immunofluorescence staining for the mitotic marker phosphorylated histone H3 (phospho-histone H3 or pH3). When wandering third-instar control larvae, without transgene expression, are exposed to 500 rads of X-ray or γ-ray irradiation, the number of pH3-positive cells in wing imaginal discs is reduced from hundreds before irradiation to approximately 30 after irradiation, with an equal distribution between the anterior and posterior compartments (Yan et al., 2011, FASEB J). Using the GAL4/UAS system, RNAi, cDNA, or microRNA sponge transgenes can be expressed in the posterior compartment of the wing disc using drivers such as engrailed (en)-Gal4, while the anterior compartment serves as an internal control. This approach makes it possible to do genome-wide genetic screening for molecules involved in radiation-induced cell cycle arrest. PMID:21870287

  13. Bcl-xL controls a switch between cell death modes during mitotic arrest

    PubMed Central

    Bah, N; Maillet, L; Ryan, J; Dubreil, S; Gautier, F; Letai, A; Juin, P; Barillé-Nion, S

    2014-01-01

    Antimitotic agents such as microtubule inhibitors (paclitaxel) are widely used in cancer therapy while new agents blocking mitosis onset are currently in development. All these agents impose a prolonged mitotic arrest in cancer cells that relies on sustained activation of the spindle assembly checkpoint and may lead to subsequent cell death by incompletely understood molecular events. We have investigated the role played by anti-apoptotic Bcl-2 family members in the fate of mitotically arrested mammary tumor cells treated with paclitaxel, or depleted in Cdc20, the activator of the anaphase promoting complex. Under these conditions, a weak and delayed mitotic cell death occurs that is caspase- and Bax/Bak-independent. Moreover, BH3 profiling assays indicate that viable cells during mitotic arrest are primed to die by apoptosis and that Bcl-xL is required to maintain mitochondrial integrity. Consistently, Bcl-xL depletion, or treatment with its inhibitor ABT-737 (but not with the specific Bcl-2 inhibitor ABT-199), during mitotic arrest converts cell response to antimitotics to efficient caspase and Bax-dependent apoptosis. Apoptotic priming under conditions of mitotic arrest relies, at least in part, on the phosphorylation on serine 62 of Bcl-xL, which modulates its interaction with Bax and its sensitivity to ABT-737. The phospho-mimetic S62D-Bcl-xL mutant is indeed less efficient than the corresponding phospho-deficient S62A-Bcl-xL mutant in sequestrating Bax and in protecting cancer cells from mitotic cell death or yeast cells from Bax-induced growth inhibition. Our results provide a rationale for combining Bcl-xL targeting to antimitotic agents to improve clinical efficacy of antimitotic strategy in cancer therapy. PMID:24922075

  14. Glucocorticoid receptor-mediated cell cycle arrest is achieved through distinct cell-specific transcriptional regulatory mechanisms.

    PubMed Central

    Rogatsky, I; Trowbridge, J M; Garabedian, M J

    1997-01-01

    Glucocorticoids inhibit proliferation of many cell types, but the events leading from the activated glucocorticoid receptor (GR) to growth arrest are not understood. Ectopic expression and activation of GR in human osteosarcoma cell lines U2OS and SAOS2, which lack endogenous receptors, result in a G1 cell cycle arrest. GR activation in U2OS cells represses expression of the cyclin-dependent kinases (CDKs) CDK4 and CDK6 as well as their regulatory partner, cyclin D3, leading to hypophosphorylation of the retinoblastoma protein (Rb). We also demonstrate a ligand-dependent reduction in the expression of E2F-1 and c-Myc, transcription factors involved in the G1-to-S-phase transition. Mitogen-activated protein kinase, CDK2, cyclin E, and the CDK inhibitors (CDIs) p27 and p21 are unaffected by receptor activation in U2OS cells. The receptor's N-terminal transcriptional activation domain is not required for growth arrest in U2OS cells. In Rb-deficient SAOS2 cells, however, the expression of p27 and p21 is induced upon receptor activation. Remarkably, in SAOS2 cells that express a GR deletion derivative lacking the N-terminal transcriptional activation domain, induction of CDI expression is abolished and the cells fail to undergo ligand-dependent cell cycle arrest. Similarly, murine S49 lymphoma cells, which, like SAOS2 cells, lack Rb, require the N-terminal activation domain for growth arrest and induce CDI expression upon GR activation. These cell-type-specific differences in receptor domains and cellular targets linking GR activation to cell cycle machinery suggest two distinct regulatory mechanisms of GR-mediated cell cycle arrest: one involving transcriptional repression of G1 cyclins and CDKs and the other involving enhanced transcription of CDIs by the activated receptor. PMID:9154817

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

    SciTech Connect

    Suzuki, Kanayo; Sakaguchi, Minoru; Tanaka, Satoshi; Yoshimoto, Tadashi; Takaoka, Masanori

    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.

  16. A novel anticancer agent, decursin, induces G1 arrest and apoptosis in human prostate carcinoma cells.

    PubMed

    Yim, Dongsool; Singh, Rana P; Agarwal, Chapla; Lee, Sookyeon; Chi, Hyungjoon; Agarwal, Rajesh

    2005-02-01

    We isolated a coumarin compound decursin (C(19)H(20)O(5); molecular weight 328) from Korean angelica (Angelica gigas) root and characterized it by spectroscopy. Here, for the first time, we observed that decursin (25-100 micromol/L) treatment for 24 to 96 hours strongly inhibits growth and induces death in human prostate carcinoma DU145, PC-3, and LNCaP cells. Furthermore, we observed that decursinol [where (CH(3))(2)-C=CH-COO- side chain of decursin is substituted with -OH] has much lower effects compared with decursin, suggesting a possible structure-activity relationship. Decursin-induced growth inhibition was associated with a strong G(1) arrest (P < 0.001) in DU145 and LNCaP cells, and G(1), S as well as G(2)-M arrests depending upon doses and treatment times in PC-3 cells. Comparatively, decursin was nontoxic to human prostate epithelial PWR-1E cells and showed only moderate growth inhibition and G(1) arrest. Consistent with G(1) arrest in DU145 cells, decursin strongly increased protein levels of Cip1/p21 but showed a moderate increase in Kip1/p27 with a decrease in cyclin-dependent kinases (CDK); CDK2, CDK4, CDK6, and cyclin D1, and inhibited CDK2, CDK4, CDK6, cyclin D1, and cyclin E kinase activity, and increased binding of CDK inhibitor (CDKI) with CDK. Decursin-caused cell death was associated with an increase in apoptosis (P < 0.05-0.001) and cleaved caspase-9, caspase-3, and poly(ADP-ribose) polymerase; however, pretreatment with all-caspases inhibitor (z-VAD-fmk) only partially reversed decursin-induced apoptosis, suggesting the involvement of both caspase-dependent and caspase-independent pathways. These findings suggest the novel anticancer efficacy of decursin mediated via induction of cell cycle arrest and apoptosis selectively in human prostate carcinoma cells.

  17. Dihydroartemisinin (DHA) induces ferroptosis and causes cell cycle arrest in head and neck carcinoma cells.

    PubMed

    Lin, Renyu; Zhang, Ziheng; Chen, Lingfeng; Zhou, Yunfang; Zou, Peng; Feng, Chen; Wang, Li; Liang, Guang

    2016-10-10

    Head and neck cancer is the sixth most common cancer worldwide. Dihydroartemisinin (DHA), a semi-synthetic derivative of artemisinin, exhibits a wide range of biological roles including a highly efficient and specific anti-tumor activity. Here, we aimed to examine the effect of DHA on head and neck carcinoma cells and elucidate the potential mechanisms. We used five head and neck carcinoma cell lines and two non-tumorigenic normal epithelial cell lines to achieve our goals. Cells were exposed to DHA and subjected to cellular activity assays including viability, cell cycle analysis, cell death, and angiogenic phenotype. Our results show that DHA causes cell cycle arrest which is mediated through Forkhead box protein M1 (FOXM1). We also demonstrate that DHA induces ferroptosis and apoptosis in head and neck carcinoma cells. Lastly, our results show that DHA alters the angiogenic phenotype of cancer cells by reducing the expression of angiogenic factors and the ability of cancer cells to support endothelial cell tubule formation. Our study suggests that DHA specifically causes head and neck cancer cell death through contribution from both ferroptosis and apoptosis. DHA may represent an effective strategy in head and neck cancer treatment.

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

    SciTech Connect

    Galán-Malo, Patricia; Vela, Laura; Gonzalo, Oscar; Calvo-Sanjuán, Rubén; Gracia-Fleta, Lucía; Naval, Javier; Marzo, Isabel

    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.

  19. Actinobacillus actinomycetemcomitans toxin induces both cell cycle arrest in the G2/M phase and apoptosis.

    PubMed

    Ohguchi, M; Ishisaki, A; Okahashi, N; Koide, M; Koseki, T; Yamato, K; Noguchi, T; Nishihara, T

    1998-12-01

    We found that the culture supernatant of the periodontopathic bacterium Actinobacillus actinomycetemcomitans had a cytotoxic effect on several cell lines. In this study, we purified the toxin from the culture supernatant of A. actinomycetemcomitans Y4 by a four-step procedure: ammonium sulfate precipitation, POROS HQ/M column chromatography, polymyxin B matrix column chromatography, and Mono-Q column chromatography. The purified toxin gave two major bands of protein with molecular masses of 80 and 85 kDa upon sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The mechanism of cell death of the B-cell hybridoma cell line HS-72 was examined by observing changes in nuclear morphology, an increase in the proportion of fragmented DNA, and the typical ladder pattern of degraded chromosomal DNA, indicating the induction of apoptosis. Overexpression of human Bcl-2 suppressed apoptosis in HS-72 cells, indicating that the toxin from A. actinomycetemcomitans induces apoptosis by a Bcl-2-inhibitable mechanism. Flow cytometric analysis revealed that the toxin caused cell cycle arrest in the G2/M phase and apoptosis in HS-72 cells. In addition, aurintricarboxylic acid, a DNA endonuclease inhibitor, markedly decreased the percentage of apoptotic cells but had no effect on cell cycle arrest in the G2/M phase. Taken together, these findings suggest that the toxin from A. actinomycetemcomitans could mediate the development of periodontal diseases through cell cycle arrest in the G2/M phase and apoptosis in B lymphocytes of periodontal tissue. PMID:9826381

  20. Sodium butyrate induces retinoblastoma protein dephosphorylation, p16 expression and growth arrest of colon cancer cells.

    PubMed

    Schwartz, B; Avivi-Green, C; Polak-Charcon, S

    1998-11-01

    Sodium butyrate causes alteration of colon cancer cell morphology and biology towards that of a more differentiated phenotype. The retinoblastoma gene encodes a nuclear phosphoprotein (pRb) present in a wide range of human cancer cell lines including colon cancer cell lines. pRB is synthesized throughout the cell cycle and phosphorylated in a phase specific manner: the predominant proteins in G0/G1 are the unphosphorylated species (110 kD) whereas phosphorylated pRb (112-114 kD) are in S and G2. 110 kD pRb binds transcription factors and prevents transcription of responsive genes such as the gene for thymidine kinase, which are expressed in late G1. The precise mechanisms controlling cell arrest are unknown, but recent data suggest that cyclin-dependent kinase inhibitors such as p16 may play a role. The aim of the present study was to assess the effect of sodium butyrate on cell cycle staging, thymidine kinase activity, phosphorylation of the pRb protein and expression of p16. We show that sodium butyrate treatment induces differentiation of LS174T colon cancer cells, inhibits thymidine kinase activity concomitantly with induction of pRb dephosphorylation, p16 transcription and cell cycle arrest at G0/G1. Initial dephosphorylation was observed 24 h after treatment of LS174T cells with sodium butyrate, whereas complete shift to the dephosphorylated form was observed 3 days after treatment. Induction of pRb dephosphorylation by sodium butyrate preceded inhibition of growth and the specific cell cycle arrest. RNase protection assay with a p16 specific riboprobe showed undetectable levels in proliferating cells to several fold increase in differentiated colonocytes. In conclusion, the results provide evidence for a specific cellular mechanism of butyrate induced growth arrest and differentiation of a colon cancer cell line.

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

    PubMed Central

    Yu, Xi; Su, Boxing; Ge, Peng; Wang, Zicheng; Li, Sen; Huang, Bingwei; Gong, Yanqing; Lin, Jian

    2015-01-01

    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. PMID:25691904

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

    PubMed Central

    2013-01-01

    Background 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. Methods 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. Results 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. Conclusions 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. PMID:23915425

  3. Resveratrol causes cell cycle arrest, decreased collagen synthesis, and apoptosis in rat intestinal smooth muscle cells.

    PubMed

    Garcia, Patricia; Schmiedlin-Ren, Phyllissa; Mathias, Jason S; Tang, Huaijing; Christman, Gregory M; Zimmermann, Ellen M

    2012-02-01

    One of the most difficult and treatment-resistant complications of Crohn's disease is the development of fibrotic intestinal strictures due to mesenchymal cell hyperplasia and collagen deposition. Resveratrol, a phytoalexin found in berries, peanuts, grapes, and red wine, has been shown to inhibit fibrosis in vasculature, heart, lung, kidney, liver, and esophagus in animal models. Resveratrol has also been shown to inhibit oxidation, inflammation, and cell proliferation and to decrease collagen synthesis in several cell types or animal models. The aim of this study was to determine whether resveratrol has antifibrotic effects on intestinal smooth muscle cells. Responses to resveratrol by cultured smooth muscle cells isolated from colons of untreated Lewis rats were examined; this rat strain is used in a model of Crohn's disease with prominent intestinal fibrosis. A relative decrease in cell numbers following treatment with 50 and 100 μM resveratrol was evident at 24 h (P ≤ 0.005). This effect was largely due to cell cycle arrest, with an increase in the percent of cells in S phase from 8 to 25-35% (P < 0.05). Cell viability was unchanged until 2-3 days of treatment when there was a 1.2- to 5.0-fold increase in the percent of apoptotic cells, depending on the assay (P < 0.05). Expression of collagen type I protein was decreased following treatment with resveratrol for 24 h (to 44 and 25% of control levels with 50 and 100 μM resveratrol, respectively; P < 0.05). Expression of procollagen types I and III mRNA was also decreased with resveratrol treatment. Resveratrol (50 μM) diminished the proliferative response to TGF-β₁ (P = 0.02) as well as IGF-I-stimulated collagen production (P = 0.02). Thus resveratrol decreases intestinal smooth muscle cell numbers through its effects on cell cycle arrest and apoptosis and also decreases collagen synthesis by the cells. These effects could be useful in preventing the smooth muscle cell hyperplasia and collagen

  4. Solena amplexicaulis induces cell cycle arrest, apoptosis and inhibits angiogenesis in hepatocarcinoma cells and HUVECs.

    PubMed

    Ren, Jie; Xu, Yuan Yuan; Jiang, He Fei; Yang, Meng; Huang, Qian Hui; Yang, Jie; Hu, Kun; Wei, Kun

    2014-01-01

    Solena amplexicaulis (Lam.) Gandhi (SA) has been used as a traditional medicine for the treatment of dysentery, multiple abscess, gastralgia, urethritis, and eczema in the minority area of China. This study was aimed to examine the cell proliferation inhibitory activity of the SA extract (SACE) and its mechanism of action in human hepatoma cell line (HepG2) and evaluate its anti-angiogenesis activity in human umbilical vein endothelial cell line (HUVEC). SACE could inhibit the growth of HepG2 cells in a dose- and time-dependent manner. FCM analysis showed that SACE could induce G2/M phase arrest, cell apoptosis, the mitochondrial membrane potential loss (ΔΨm) and increase the production of intracellular ROS of HepG2 cells. After treatment with SACE, topical morphological changes of apoptotic body formation, obvious increase of apoptosis-related protein expressions, such as Bax, cytochrome c, caspase-3, PARP-1, and decrease of Bcl-2, procaspase-9 protein expressions were observed at the same time. Moreover, SACE caused the significant inhibition of endothelial cell migration and tube formation in HUVEC cells. The results suggested that SACE could act as an angiogenesis inhibitor and induce cell apoptosis via a caspase-dependent mitochondrial pathway. Therefore, SACE could be a potent candidate for the prevention and treatment of liver cancer. PMID:25547924

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

    NASA Technical Reports Server (NTRS)

    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.

  6. Tumor cell cycle arrest induced by shear stress: Roles of integrins and Smad

    PubMed Central

    Chang, Shun-Fu; Chang, Cheng Allen; Lee, Ding-Yu; Lee, Pei-Ling; Yeh, Yu-Ming; Yeh, Chiuan-Ren; Cheng, Cheng-Kung; Chien, Shu; Chiu, Jeng-Jiann

    2008-01-01

    Interstitial flow in and around tumor tissue affects the mechanical microenvironment to modulate tumor cell growth and metastasis. We investigated the roles of flow-induced shear stress in modulating cell cycle distribution in four tumor cell lines and the underlying mechanisms. In all four cell lines, incubation under static conditions for 24 or 48 h led to G0/G1 arrest; in contrast, shear stress (12 dynes/cm2) induced G2/M arrest. The molecular basis of the shear effect was analyzed, and the presentation on molecular mechanism is focused on human MG63 osteosarcoma cells. Shear stress induced increased expressions of cyclin B1 and p21CIP1 and decreased expressions of cyclins A, D1, and E, cyclin-dependent protein kinases (Cdk)-1, -2, -4, and -6, and p27KIP1 as well as a decrease in Cdk1 activity. Using specific antibodies and small interfering RNA, we found that the shear-induced G2/M arrest and corresponding changes in G2/M regulatory protein expression and activity were mediated by αvβ3 and β1 integrins through bone morphogenetic protein receptor type IA-specific Smad1 and Smad5. Shear stress also down-regulated runt-related transcription factor 2 (Runx2) binding activity and osteocalcin and alkaline phosphatase expressions in MG63 cells; these responses were mediated by αvβ3 and β1 integrins through Smad5. Our findings provide insights into the mechanism by which shear stress induces G2/M arrest in tumor cells and inhibits cell differentiation and demonstrate the importance of mechanical microenvironment in modulating molecular signaling, gene expression, cell cycle, and functions in tumor cells. PMID:18310319

  7. G1-arrested newborn cells are the predominant infectious form of the pathogen Brucella abortus

    PubMed Central

    Deghelt, Michaël; Mullier, Caroline; Sternon, Jean-François; Francis, Nayla; Laloux, Géraldine; Dotreppe, Delphine; Van der Henst, Charles; Jacobs-Wagner, Christine; Letesson, Jean-Jacques; De Bolle, Xavier

    2014-01-01

    Several intracellular pathogens, such as Brucella abortus, display a biphasic infection process starting with a non-proliferative stage of unclear nature. Here, we study the cell cycle of B. abortus at the single-cell level, in culture and during infection of HeLa cells and macrophages. The localization of segregation and replication loci of the two bacterial chromosomes indicates that, immediately after being engulfed by host-cell endocytic vacuoles, most bacterial cells are newborn. These bacterial cells do not initiate DNA replication for the next 4 to 6 h, indicating a G1 arrest. Moreover, growth is completely stopped during that time, reflecting a global cell cycle block. Growth and DNA replication resume later, although bacteria still reside within endosomal-like compartments. We hypothesize that the predominance of G1-arrested bacteria in the infectious population, and the bacterial cell cycle arrest following internalization, may constitute a widespread strategy among intracellular pathogens to colonize new proliferation niches. PMID:25006695

  8. Cyclin B1 overexpression induces cell death independent of mitotic arrest.

    PubMed

    Eichhorn, Joshua M; Kothari, Anisha; Chambers, Timothy C

    2014-01-01

    Microtubule inhibitors are widely used in cancer chemotherapy. These drugs characteristically induce mitotic arrest and cell death but the mechanisms linking the two are not firmly established. One of the problems is that cancer cells vary widely in their sensitivity to these agents, and thus comparison of data from different systems is difficult. To alleviate this problem we sought to molecularly induce mitotic death and study its mechanisms, by expressing non-degradable cyclin B (R42A) in HeLa cells. However, this approach failed to induce significant mitotic arrest, Cdk1 activation, or phosphorylation of anti-apoptotic Bcl-2 proteins, all characteristics of cells treated with microtubule inhibitors. Furthermore, cyclin B1-R42A induced rapid cell death, and when expressed in synchronized cells, cell death occurred in G1 phase. Decreasing the plasmid concentration reduced transfection efficiency but restored mitotic arrest and eliminated non-specific death. These results show that inappropriate overexpression of cyclin B1 causes non-specific cell death and suggest caution in its use for the study of mitotic events.

  9. Metformin Induces Cell Cycle Arrest and Apoptosis in Drug-Resistant Leukemia Cells

    PubMed Central

    Rodríguez-Lirio, A.; Pérez-Yarza, G.; Fernández-Suárez, M. R.; Alonso-Tejerina, E.; Boyano, M. D.; Asumendi, A.

    2015-01-01

    Recent epidemiological studies indicate that the antidiabetic drug metformin has chemosensitizing and chemopreventive effects against carcinogenesis. Here, we demonstrate that metformin exerts varying degrees of antitumor activity against human leukemia cells, as reflected by differences in growth inhibition, apoptosis, and alterations to metabolic enzymes. In metformin-sensitive cells, autophagy was not induced but rather it blocked proliferation by means of arresting cells in the S and G2/M phases which was associated with the downregulation of cyclin A, cyclin B1, and cdc2, but not that of cyclin E. In 10E1-CEM cells that overexpress Bcl-2 and are drug-resistant, the effect of metformin on proliferation was more pronounced, also inducing the activation of the caspases 3/7 and hence apoptosis. In all sensitive cells, metformin decreased the Δψm and it modified the expression of enzymes involved in energy metabolism: PKCε (PKCepsilon) and PKCδ (PKCdelta). In sensitive cells, metformin altered PKCε and PKCδ expression leading to a predominance of PKCε over PKCδ which implies a more glycolytic state. The opposite occurs in the nonresponsive cells. In conclusion, we provide new insights into the activity of metformin as an antitumoral agent in leukemia cells that could be related to its capability to modulate energy metabolism. PMID:26688757

  10. Low dose of amino-modified nanoparticles induces cell cycle arrest.

    PubMed

    Kim, Jong Ah; Åberg, Christoffer; de Cárcer, Guillermo; Malumbres, Marcos; Salvati, Anna; Dawson, Kenneth A

    2013-09-24

    The interaction of nanoscaled materials with biological systems is currently the focus of a fast-growing area of investigation. Though many nanoparticles interact with cells without acute toxic responses, amino-modified polystyrene nanoparticles are known to induce cell death. We have found that by lowering their dose, cell death remains low for several days while, interestingly, cell cycle progression is arrested. In this scenario, nanoparticle uptake, which we have recently shown to be affected by cell cycle progression, develops differently over time due to the absence of cell division. This suggests that the same nanoparticles can trigger different pathways depending on exposure conditions and the dose accumulated.

  11. Induced Developmental Arrest of Early Hematopoietic Progenitors Leads to the Generation of Leukocyte Stem Cells

    PubMed Central

    Ikawa, Tomokatsu; Masuda, Kyoko; Huijskens, Mirelle J.A.J.; Satoh, Rumi; Kakugawa, Kiyokazu; Agata, Yasutoshi; Miyai, Tomohiro; Germeraad, Wilfred T.V.; Katsura, Yoshimoto; Kawamoto, Hiroshi

    2015-01-01

    Summary Self-renewal potential and multipotency are hallmarks of a stem cell. It is generally accepted that acquisition of such stemness requires rejuvenation of somatic cells through reprogramming of their genetic and epigenetic status. We show here that a simple block of cell differentiation is sufficient to induce and maintain stem cells. By overexpression of the transcriptional inhibitor ID3 in murine hematopoietic progenitor cells and cultivation under B cell induction conditions, the cells undergo developmental arrest and enter a self-renewal cycle. These cells can be maintained in vitro almost indefinitely, and the long-term cultured cells exhibit robust multi-lineage reconstitution when transferred into irradiated mice. These cells can be cloned and re-expanded with 50% plating efficiency, indicating that virtually all cells are self-renewing. Equivalent progenitors were produced from human cord blood stem cells, and these will ultimately be useful as a source of cells for immune cell therapy. PMID:26607950

  12. Dietary NiCl2 causes G2/M cell cycle arrest in the broiler's kidney

    PubMed Central

    Guo, Hongrui; Cui, Hengmin; Peng, Xi; Fang, Jing; Zuo, Zhicai; Deng, Junliang; Wang, Xun; Wu, Bangyuan; Chen, Kejie; Deng, Jie

    2015-01-01

    Here we showed that dietary NiCl2 in excess of 300 mg/kg caused the G2/M cell cycle arrest and the reduction of cell proportion at S phase. The G2/M cell cycle arrest was accompanied by up-regulation of phosphorylated ataxia telangiectasia mutated (p-ATM), p53, p-Chk1, p-Chk2, p21 protein expression and ATM, p53, p21, Chk1, Chk2 mRNA expression, and down-regulation of p-cdc25C, cdc2, cyclinB and proliferating cell nuclear antigen (PCNA) protein expression and the cdc25, cdc2, cyclinB, PCNA mRNA expression. PMID:26440151

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

    NASA Astrophysics Data System (ADS)

    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.

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

    PubMed

    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.

  15. Somatostatin Receptor-1 Induces Cell Cycle Arrest and Inhibits Tumor Growth in Pancreatic Cancer

    PubMed Central

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

    2010-01-01

    Functional somatostatin receptors (SSTRs) 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 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 G0/G1 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, t-test), and inhibited tumor weight by 69% and 47%, (n=5, p<0.05, 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

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

    PubMed

    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.

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

    PubMed Central

    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

  18. Specific phase arrest of cell cycle restores cell viability against tRNA cleavage by killer toxin.

    PubMed

    Shigematsu, Megumi; Ogawa, Tetsuhiro; Kitamoto, Hiroko K; Hidaka, Makoto; Masaki, Haruhiko

    2012-04-20

    Zymocin and PaT are killer toxins that induce cell cycle arrest of sensitive yeast cells in G1 and S phase, respectively. Recent studies have revealed that these two toxins cleave specific tRNAs, indicating that the cell growth impairment is due to the tRNA cleavage. Additionally, we have previously shown that the active domain of colicin D (D-CRD), which also cleaves specific Escherichia coli tRNAs, statically impairs growth when expressed in yeast cells. To verify that phase-specific cell cycle arrest is also induced by the expression of D-CRD, D-CRD and the subunits of zymocin and PaT that have tRNA cleaving activity were expressed in yeast cells and cell cycle status was analyzed. Our results indicate that phase-specific arrest does not commonly occur by tRNA cleavage, and it saves the cell viability. Furthermore, the extent of protein synthesis impairment may determine the phase specificity of cell cycle arrest. PMID:22450321

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

    PubMed

    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

  20. Vascular networks due to dynamically arrested crystalline ordering of elongated cells

    NASA Astrophysics Data System (ADS)

    Palm, Margriet M.; Merks, Roeland M. H.

    2013-01-01

    Recent experimental and theoretical studies suggest that crystallization and glass-like solidification are useful analogies for understanding cell ordering in confluent biological tissues. It remains unexplored how cellular ordering contributes to pattern formation during morphogenesis. With a computational model we show that a system of elongated, cohering biological cells can get dynamically arrested in a network pattern. Our model provides an explanation for the formation of cellular networks in culture systems that exclude intercellular interaction via chemotaxis or mechanical traction.

  1. Occurrence and control of sporadic proliferation in growth arrested Swiss 3T3 feeder cells.

    PubMed

    Chugh, Rishi Man; Chaturvedi, Madhusudan; Yerneni, Lakshmana Kumar

    2015-01-01

    Growth arrested Swiss mouse embryonic 3T3 cells are used as feeders to support the growth of epidermal keratinocytes and several other target cells. The 3T3 cells have been extensively subcultured owing to their popularity and wide distribution in the world and, as a consequence selective inclusion of variants is a strong possibility in them. Inadvertently selected variants expressing innate resistance to mitomycin C may continue to proliferate even after treatment with such growth arresting agents. The failure of growth arrest can lead to a serious risk of proliferative feeder contamination in target cell cultures. In this study, we passaged Swiss 3T3 cells (CCL-92, ATCC) by different seeding densities and incubation periods. We tested the resultant cultures for differences in anchorage-independent growth, resumption of proliferation after mitomycin C treatment and occurrence of proliferative feeder contaminants in an epidermal keratinocyte co-culture system. The study revealed subculture dependent differential responses. The cultures of a particular subculture procedure displayed unique cell size distribution and disintegrated completely in 6 weeks following mitomycin C treatment, but their repeated subculture resulted in feeder regrowth as late as 11 weeks after the growth arrest. In contrast, mitomycin C failed to inhibit cell proliferation in cultures of the other subculture schemes and also in a clone that was established from a transformation focus of super-confluent culture. The resultant proliferative feeder cells contaminated the keratinocyte cultures. The anchorage-independent growth appeared in late passages as compared with the expression of mitomycin C resistance in earlier passages. The feeder regrowth was prevented by identifying a safe subculture protocol that discouraged the inclusion of resistant variants. We advocate routine anchorage-independent growth assay and absolute confirmation of feeder disintegration to qualify feeder batches and

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

    PubMed Central

    Postiglione, Ilaria; Chiaviello, Angela; Barra, Federica; Roscetto, Emanuela; Soriano, Amata A.; Catania, Maria Rosaria; Palumbo, Giuseppe; Pierantoni, Giovanna Maria

    2015-01-01

    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. PMID:26343643

  3. Cis-Suppression to Arrest Protein Aggregation in Mammalian Cells

    PubMed Central

    Gregoire, Simpson; Zhang, Shaojie; Costanzo, Joseph; Wilson, Kelly; Fernandez, Erik J.; Kwon, Inchan

    2015-01-01

    Protein misfolding and aggregation are implicated in numerous human diseases and significantly lower production yield of proteins expressed in mammalian cells. Despite the importance of understanding and suppressing protein aggregation in mammalian cells, a protein design and selection strategy to modulate protein misfolding/aggregation in mammalian cells has not yet been reported. In this work, we address the particular challenge presented by mutation-induced protein aggregation in mammalian cells. We hypothesize that an additional mutation(s) can be introduced in an aggregation-prone protein variant, spatially near the original mutation, to suppress misfolding and aggregation (cis-suppression). As a model protein, we chose human copper, zinc superoxide dismutase mutant (SOD1A4V) containing an alanine to valine mutation at residue 4, associated with the familial form of amyotrophic lateral sclerosis. We used the program RosettaDesign to identify Phe20 in SOD1A4V as a key residue responsible for SOD1A4V conformational destabilization. This information was used to rationally develop a pool of candidate mutations at the Phe20 site. After two rounds of mammalian-cell based screening of the variants, three novel SOD1A4V variants with a significantly reduced aggregation propensity inside cells were selected. The enhanced stability and reduced aggregation propensity of the three novel SOD1A4V variants were verified using cell fractionation and in vitro stability assays. PMID:24114411

  4. Hispolon induces apoptosis and cell cycle arrest of human hepatocellular carcinoma Hep3B cells by modulating ERK phosphorylation.

    PubMed

    Huang, Guan-Jhong; Deng, Jeng-Shyan; Huang, Shyh-Shyun; Hu, Miao-Lin

    2011-07-13

    Hispolon is an active phenolic compound of Phellinus igniarius , a mushroom that has recently been shown to have antioxidant, anti-inflammatory, and anticancer activities. This study investigated the antiproliferative effect of hispolon on human hepatocellular carcinoma Hep3B cells by using the MTT assay, DNA fragmentation, DAPI (4,6-diamidino-2-phenylindole dihydrochloride) staining, and flow cytometric analyses. Hispolon inhibited cellular growth of Hep3B cells in a time-dependent and dose-dependent manner, through the induction of cell cycle arrest at S phase measured using flow cytometric analysis and apoptotic cell death, as demonstrated by DNA laddering. Hispolon-induced S-phase arrest was associated with a marked decrease in the protein expression of cyclins A and E and cyclin-dependent kinase (CDK) 2, with concomitant induction of p21waf1/Cip1 and p27Kip1. Exposure of Hep3B cells to hispolon resulted in apoptosis as evidenced by caspase activation, PARP cleavage, and DNA fragmentation. Hispolon treatment also activated JNK, p38 MAPK, and ERK expression. Inhibitors of ERK (PB98095), but not those of JNK (SP600125) and p38 MAPK (SB203580), suppressed hispolon-induced S-phase arrest and apoptosis in Hep3B cells. These findings establish a mechanistic link between the MAPK pathway and hispolon-induced cell cycle arrest and apoptosis in Hep3B cells. PMID:21630638

  5. Fangchinoline induces G1 arrest in breast cancer cells through cell-cycle regulation.

    PubMed

    Xing, Zhibo; Zhang, Youxue; Zhang, Xianyu; Yang, Yanmei; Ma, Yuyan; Pang, Da

    2013-12-01

    Fangchinoline, an alkaloid derived from the dry roots of Stephaniae tetrandrine S. Moore (Menispermaceae), has been shown to possess cytotoxic, anti-inflammatory, and antioxidant properties. In this study, we used Fangchinoline to inhibit breast cancer cell proliferation and to investigate its underlying molecular mechanisms. Human breast cancer cell lines, MCF-7 and MDA-MB-231, were both used in this study. We found that Fangchinoline significantly decreased cell proliferation in a dose-dependent manner and induced G1-phase arrest in both cell lines. In addition, upon analysis of expression of cell cycle-related proteins, we found that Fangchinoline reduced expression of cyclin D1, cyclin D3, and cyclin E, and increased expression of the cyclin-dependent kinase (CDK) inhibitors, p21/WAF1, and p27/KIP1. Moreover, Fangchinoline also inhibited the kinase activities of CDK2, CDK4, and CDK6. These results suggest that Fangchinoline can inhibit human breast cancer cell proliferation and thus may have potential applications in cancer therapy. PMID:23401195

  6. Arecoline induced cell cycle arrest, apoptosis, and cytotoxicity to human endothelial cells.

    PubMed

    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.

  7. Galiellalactone induces cell cycle arrest and apoptosis through the ATM/ATR pathway in prostate cancer cells.

    PubMed

    García, Víctor; Lara-Chica, Maribel; Cantarero, Irene; Sterner, Olov; Calzado, Marco A; Muñoz, Eduardo

    2016-01-26

    Galiellalactone (GL) is a fungal metabolite that presents antitumor activities on prostate cancer in vitro and in vivo. In this study we show that GL induced cell cycle arrest in G2/M phase, caspase-dependent apoptosis and also affected the microtubule organization and migration ability in DU145 cells. GL did not induce double strand DNA break but activated the ATR and ATM-mediated DNA damage response (DDR) inducing CHK1, H2AX phosphorylation (fH2AX) and CDC25C downregulation. Inhibition of the ATM/ATR activation with caffeine reverted GL-induced G2/M cell cycle arrest, apoptosis and DNA damage measured by fH2AX. In contrast, UCN-01, a CHK1 inhibitor, prevented GL-induced cell cycle arrest but enhanced apoptosis in DU145 cells. Furthermore, we found that GL did not increase the levels of intracellular ROS, but the antioxidant N-acetylcysteine (NAC) completely prevented the effects of GL on fH2AX, G2/M cell cycle arrest and apoptosis. In contrast to NAC, other antioxidants such as ambroxol and EGCG did not interfere with the activity of GL on cell cycle. GL significantly suppressed DU145 xenograft growth in vivo and induced the expression of fH2AX in the tumors. These findings identify for the first time that GL activates DDR in prostate cancer.

  8. Galiellalactone induces cell cycle arrest and apoptosis through the ATM/ATR pathway in prostate cancer cells

    PubMed Central

    García, Víctor; Lara-Chica, Maribel; Cantarero, Irene; Sterner, Olov; Calzado, Marco A.; Muñoz, Eduardo

    2016-01-01

    Galiellalactone (GL) is a fungal metabolite that presents antitumor activities on prostate cancer in vitro and in vivo. In this study we show that GL induced cell cycle arrest in G2/M phase, caspase-dependent apoptosis and also affected the microtubule organization and migration ability in DU145 cells. GL did not induce double strand DNA break but activated the ATR and ATM-mediated DNA damage response (DDR) inducing CHK1, H2AX phosphorylation (fH2AX) and CDC25C downregulation. Inhibition of the ATM/ATR activation with caffeine reverted GL-induced G2/M cell cycle arrest, apoptosis and DNA damage measured by fH2AX. In contrast, UCN-01, a CHK1 inhibitor, prevented GL-induced cell cycle arrest but enhanced apoptosis in DU145 cells. Furthermore, we found that GL did not increase the levels of intracellular ROS, but the antioxidant N-acetylcysteine (NAC) completely prevented the effects of GL on fH2AX, G2/M cell cycle arrest and apoptosis. In contrast to NAC, other antioxidants such as ambroxol and EGCG did not interfere with the activity of GL on cell cycle. GL significantly suppressed DU145 xenograft growth in vivo and induced the expression of fH2AX in the tumors. These findings identify for the first time that GL activates DDR in prostate cancer. PMID:26683224

  9. Cell Arrest and Cell Death in Mammalian Preimplantation Development: Lessons from the Bovine Model

    PubMed Central

    Leidenfrost, Sandra; Boelhauve, Marc; Reichenbach, Myriam; Güngör, Tuna; Reichenbach, Horst-Dieter; Sinowatz, Fred; Wolf, Eckhard; Habermann, Felix A.

    2011-01-01

    Background The causes, modes, biological role and prospective significance of cell death in preimplantation development in humans and other mammals are still poorly understood. Early bovine embryos represent a very attractive experimental model for the investigation of this fundamental and important issue. Methods and Findings To obtain reference data on the temporal and spatial occurrence of cell death in early bovine embryogenesis, three-dimensionally preserved embryos of different ages and stages of development up to hatched blastocysts were examined in toto by confocal laser scanning microscopy. In parallel, transcript abundance profiles for selected apoptosis-related genes were analyzed by real-time reverse transcriptase-polymerase chain reaction. Our study documents that in vitro as well as in vivo, the first four cleavage cycles are prone to a high failure rate including different types of permanent cell cycle arrest and subsequent non-apoptotic blastomere death. In vitro produced and in vivo derived blastocysts showed a significant incidence of cell death in the inner cell mass (ICM), but only in part with morphological features of apoptosis. Importantly, transcripts for CASP3, CASP9, CASP8 and FAS/FASLG were not detectable or found at very low abundances. Conclusions In vitro and in vivo, errors and failures of the first and the next three cleavage divisions frequently cause immediate embryo death or lead to aberrant subsequent development, and are the main source of developmental heterogeneity. A substantial occurrence of cell death in the ICM even in fast developing blastocysts strongly suggests a regular developmentally controlled elimination of cells, while the nature and mechanisms of ICM cell death are unclear. Morphological findings as well as transcript levels measured for important apoptosis-related genes are in conflict with the view that classical caspase-mediated apoptosis is the major cause of cell death in early bovine development. PMID

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

    SciTech Connect

    Su, Miaoxian; Chung, Hau Yin; Li, Yaolan

    2011-07-29

    Highlights: {yields} Deoxyelephantopin (ESD) inhibited cell proliferation in the human nasopharyngeal cancer CNE cells. {yields} ESD induced cell cycle arrest in S and G2/M phases via modulation of cell cycle regulatory proteins. {yields} ESD triggered apoptosis by dysfunction of mitochondria and induction of both intrinsic and extrinsic apoptotic signaling pathways. {yields} 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 ({Delta}{Psi}m), 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).

  11. Iron depletion results in Src kinase inhibition with associated cell cycle arrest in neuroblastoma cells

    PubMed Central

    Siriwardana, Gamini; Seligman, Paul A

    2015-01-01

    Iron is required for cellular proliferation. Recently, using systematic time studies of neuroblastoma cell growth, we better defined the G1 arrest caused by iron chelation to a point in mid-G1, where cyclin E protein is present, but the cyclin E/CDK2 complex kinase activity is inhibited. In this study, we again used the neuroblastoma SKNSH cells lines to pinpoint the mechanism responsible for this G1 block. Initial studies showed in the presence of DFO, these cells have high levels of p27 and after reversal of iron chelation p27 is degraded allowing for CDK2 kinase activity. The initial activation of CDK2 kinase allows cells to exit G1 and enter S phase. Furthermore, we found that inhibition of p27 degradation by DFO is directly associated with inhibition of Src kinase activity measured by lack of phosphorylation of Src at the 416 residue. Activation of Src kinase occurs very early after reversal from the DFO G1 block and is temporally associated with initiation of cellular proliferation associated with entry into S phase. For the first time therefore we show that iron chelation inhibits Src kinase activity and this activity is a requirement for cellular proliferation. PMID:25825542

  12. Iron depletion results in Src kinase inhibition with associated cell cycle arrest in neuroblastoma cells.

    PubMed

    Siriwardana, Gamini; Seligman, Paul A

    2015-03-01

    Iron is required for cellular proliferation. Recently, using systematic time studies of neuroblastoma cell growth, we better defined the G1 arrest caused by iron chelation to a point in mid-G1, where cyclin E protein is present, but the cyclin E/CDK2 complex kinase activity is inhibited. In this study, we again used the neuroblastoma SKNSH cells lines to pinpoint the mechanism responsible for this G1 block. Initial studies showed in the presence of DFO, these cells have high levels of p27 and after reversal of iron chelation p27 is degraded allowing for CDK2 kinase activity. The initial activation of CDK2 kinase allows cells to exit G1 and enter S phase. Furthermore, we found that inhibition of p27 degradation by DFO is directly associated with inhibition of Src kinase activity measured by lack of phosphorylation of Src at the 416 residue. Activation of Src kinase occurs very early after reversal from the DFO G1 block and is temporally associated with initiation of cellular proliferation associated with entry into S phase. For the first time therefore we show that iron chelation inhibits Src kinase activity and this activity is a requirement for cellular proliferation.

  13. A mutation-promotive role of nucleotide excision repair in cell cycle-arrested cell populations following UV irradiation.

    PubMed

    Heidenreich, Erich; Eisler, Herfried; Lengheimer, Theresia; Dorninger, Petra; Steinboeck, Ferdinand

    2010-01-01

    Growing attention is paid to the concept that mutations arising in stationary, non-proliferating cell populations considerably contribute to evolution, aging, and pathogenesis. If such mutations are beneficial to the affected cell, in the sense of allowing a restart of proliferation, they are called adaptive mutations. In order to identify cellular processes responsible for adaptive mutagenesis in eukaryotes, we study frameshift mutations occurring during auxotrophy-caused cell cycle arrest in the model organism Saccharomyces cerevisiae. Previous work has shown that an exposure of cells to UV irradiation during prolonged cell cycle arrest resulted in an increased incidence of mutations. In the present work, we determined the influence of defects in the nucleotide excision repair (NER) pathway on the incidence of UV-induced adaptive mutations in stationary cells. The mutation frequency was decreased in Rad16-deficient cells and further decreased in Rad16/Rad26 double-deficient cells. A knockout of the RAD14 gene, the ortholog of the human XPA gene, even resulted in a nearly complete abolishment of UV-induced mutagenesis in cell cycle-arrested cells. Thus, the NER pathway, responsible for a normally accurate repair of UV-induced DNA damage, paradoxically is required for the generation and/or fixation of UV-induced frameshift mutations specifically in non-replicating cells.

  14. INHIBITORY EFFECT OF TETRAMETHYLPYRAZINE ON HEPATOCELLULAR CARCINOMA: POSSIBLE ROLE OF APOPTOSIS AND CELL CYCLE ARREST.

    PubMed

    Cao, J; Miao, Q; Zhang, J; Miao, S; Bi, L; Zhang, S; Yang, Q; Zhou, X; Zhang, M; Xie, Y; Wang, S

    2015-01-01

    Hepatocellular carcinoma (HCC) is the fifth most common cancer. An important approach to control HCC is chemoprevention. This study aims at investigating the antitumor effect of Tetramethylpyrazine (TMP). Rats were injected with N-Nitrosodiethylamine (DEN) to establish HCC. Tumor development was observed. Liver function was evaluated. Apoptosis and cell cycle arrest-related makers and signaling cascades were determined by Western blot, RT-PCR and flow cytometric analysis. The administration of TMP could significantly inhibit tumor development in DEN-induced HCC rats, shown by reduced incidence of tumor, decreased number of tumor nodules and reduced maximal size of tumor. DEN-induced increase of aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase and alkaline phosphatase activities were significantly inhibited by TMP. TMP exhibited inhibitory effect on HCC through induction of apoptosis and cell cycle arrest in rats. TMP induced apoptosis through increasing Bax, decreasing Bcl-2, increasing the release of cytochrome c, and activating caspase, which consisted of the mitochondrial apoptotic pathway. TMP induced G2/M cell cycle arrest through down-regulation of cyclin B1/cdc2. In addition, inhibition of Akt and ERK signaling and the antioxidant activities of TMP may also contribute to its antitumor effect. These data provide new insight into the mechanisms underlying the antitumor effect of TMP. PMID:26122217

  15. Boletus edulis biologically active biopolymers induce cell cycle arrest in human colon adenocarcinoma cells.

    PubMed

    Lemieszek, Marta Kinga; Cardoso, Claudia; Ferreira Milheiro Nunes, Fernando Hermínio; Ramos Novo Amorim de Barros, Ana Isabel; Marques, Guilhermina; Pożarowski, Piotr; Rzeski, Wojciech

    2013-04-25

    The use of biologically active compounds isolated from edible mushrooms against cancer raises global interest. Anticancer properties are mainly attributed to biopolymers including mainly polysaccharides, polysaccharopeptides, polysaccharide proteins, glycoproteins and proteins. In spite of the fact that Boletus edulis is one of the widely occurring and most consumed edible mushrooms, antitumor biopolymers isolated from it have not been exactly defined and studied so far. The present study is an attempt to extend this knowledge on molecular mechanisms of their anticancer action. The mushroom biopolymers (polysaccharides and glycoproteins) were extracted with hot water and purified by anion-exchange chromatography. The antiproliferative activity in human colon adenocarcinoma cells (LS180) was screened by means of MTT and BrdU assays. At the same time fractions' cytotoxicity was examined on the human colon epithelial cells (CCD 841 CoTr) by means of the LDH assay. Flow cytometry and Western blotting were applied to cell cycle analysis and protein expression involved in anticancer activity of the selected biopolymer fraction. In vitro studies have shown that fractions isolated from Boletus edulis were not toxic against normal colon epithelial cells and in the same concentration range elicited a very prominent antiproliferative effect in colon cancer cells. The best results were obtained in the case of the fraction designated as BE3. The tested compound inhibited cancer cell proliferation which was accompanied by cell cycle arrest in the G0/G1-phase. Growth inhibition was associated with modulation of the p16/cyclin D1/CDK4-6/pRb pathway, an aberration of which is a critical step in the development of many human cancers including colon cancer. Our results indicate that a biopolymer BE3 from Boletus edulis possesses anticancer potential and may provide a new therapeutic/preventive option in colon cancer chemoprevention.

  16. A Novel Resveratrol Based Tubulin Inhibitor Induces Mitotic Arrest and Activates Apoptosis in Cancer Cells

    PubMed Central

    Thomas, Elizabeth; Gopalakrishnan, Vidya; Hegde, Mahesh; Kumar, Sujeet; Karki, Subhas S.; Raghavan, Sathees C.; Choudhary, Bibha

    2016-01-01

    Resveratrol is one of the most widely studied bioactive plant polyphenols which possesses anticancer properties. Previously we have reported synthesis, characterization and identification of a novel resveratrol analog, SS28. In the present study, we show that SS28 induced cytotoxicity in several cancer cell lines ex vivo with an IC50 value of 3–5 μM. Mechanistic evaluation of effect of SS28 in non-small cell lung cancer cell line (A549) and T-cell leukemic cell line (CEM) showed that it inhibited Tubulin polymerization during cell division to cause cell cycle arrest at G2/M phase of the cell cycle at 12–18 h time period. Immunofluorescence studies confirmed the mitotic arrest upon treatment with SS28. Besides, we show that SS28 binds to Tubulin with a dissociation constant of 0.414 ± 0.11 μM. Further, SS28 treatment resulted in loss of mitochondrial membrane potential, activation of Caspase 9 and Caspase 3, leading to PARP-1 cleavage and finally cell death via intrinsic pathway of apoptosis. Importantly, treatment with SS28 resulted in regression of tumor in mice. Hence, our study reveals the antiproliferative activity of SS28 by disrupting microtubule dynamics by binding to its cellular target Tubulin and its potential to be developed as an anticancer molecule. PMID:27748367

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

    SciTech Connect

    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; Madden, Stephen L.; Jiang, Yide

    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.

  18. ApoG2 induces cell cycle arrest of nasopharyngeal carcinoma cells by suppressing the c-Myc signaling pathway

    PubMed Central

    Hu, Zhe-Yu; Sun, Jian; Zhu, Xiao-Feng; Yang, Dajun; Zeng, Yi-Xin

    2009-01-01

    Background apogossypolone (ApoG2) is a novel derivate of gossypol. We previously have reported that ApoG2 is a promising compound that kills nasopharyngeal carcinoma (NPC) cells by inhibiting the antiapoptotic function of Bcl-2 proteins. However, some researchers demonstrate that the antiproliferative effect of gossypol on breast cancer cells is mediated by induction of cell cycle arrest. So this study was aimed to investigate the effect of ApoG2 on cell cycle proliferation in NPC cells. Results We found that ApoG2 significantly suppressed the expression of c-Myc in NPC cells and induced arrest at the DNA synthesis (S) phase in a large percentage of NPC cells. Immunoblot analysis showed that expression of c-Myc protein was significantly downregulated by ApoG2 and that the expression of c-Myc's downstream molecules cyclin D1 and cyclin E were inhibited whereas p21 was induced. To further identify the cause-effect relationship between the suppression of c-Myc signaling pathway and induction of cell cycle arrest, the expression of c-Myc was interfered by siRNA. The results of cell cycle analysis showed that the downregulation of c-Myc signaling pathway by siRNA interference could cause a significant arrest of NPC cell at S phase of the cell cycle. In CNE-2 xenografts, ApoG2 significantly downregulated the expression of c-Myc and suppressed tumor growth in vivo. Conclusion Our findings indicated that ApoG2 could potently disturb the proliferation of NPC cells by suppressing c-Myc signaling pathway. This data suggested that the inhibitory effect of ApoG2 on NPC cell cycle proliferation might contribute to its use in anticancer therapy. PMID:19698176

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

    SciTech Connect

    Ujiki, Michael B. |; Milam, Ben; Ding Xianzhong |; Roginsky, Alexandra B.; Salabat, M. Reza; Talamonti, Mark S.; Bell, Richard H. |; Gu Wenxin; Silverman, Richard B. ||; Adrian, Thomas E. |. E-mail: tadrian@northwestern.edu

    2006-02-24

    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.

  20. R-Phycoerythrin Induces SGC-7901 Apoptosis by Arresting Cell Cycle at S Phase

    PubMed Central

    Tan, Huixin; Gao, Shiyong; Zhuang, Yan; Dong, Yanhong; Guan, Wenhui; Zhang, Kun; Xu, Jian; Cui, Jingru

    2016-01-01

    R-Phycoerythrin (R-PE), one of the chemical constituents of red algae, could produce singlet oxygen upon excitation with the appropriate radiation and possibly be used in photodynamic therapy (PDT) for cancer. Documents reported that R-PE could inhibit cell proliferation in HepG2 and A549 cells, which was significative for cancer therapy. This is due to the fact that R-PE could kill cancer cells directly as well as by PDT. However, little is known about the cytotoxicity of R-PE to the SGC-7901 cell. In this study, it has been found that R-PE could inhibit SGC-7901 proliferation and induce cell apoptosis, which was achieved by arresting the SGC-7901 cell at S phase. CyclinA, CDK2 and CDC25A are proteins associated with the S phase, and it was found that R-PE could increase the expression of cyclin A protein and decrease the expression of CDK2 and CDC25A proteins. Thus, it was concluded that R-PE reduced the CDK2 protein activated through decreasing the CDC25A factor, which reduced the formation of Cyclin-CDK complex. The reduction of Cyclin-CDK complex made the SGC-7901 cells arrest at the S phase. Therefore, R-PE induced apoptosis by arresting the SGC-7901 cell at S phase was successful, which was achieved by the expression of the CDC25A protein, which reduced the CDK2 protein actived and the formation of Cyclin-CDK complex. PMID:27626431

  1. Evodiamine induces caspase-dependent apoptosis and S phase arrest in human colon lovo cells.

    PubMed

    Zhang, Chun; Fan, Xia; Xu, Xiang; Yang, Xue; Wang, Xi; Liang, Hua-Ping

    2010-09-01

    Evodiamine, one of the major bioactive components derived from Wu-Chu-Yu, a long-standing Chinese herb, was reported to possess anticancer activity. In this study, we investigated the in-vitro and in-vivo anticancer effects of evodiamine on human colon lovo cells and their potential mechanisms. The 3-(4, 5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium bromide assay showed that the in-vitro proliferation of lovo cells was inhibited by evodiamine of various concentrations. Flow cytometry showed a time-dependent increase in the percentage of apoptotic cells and cells arrested in the S phase after treatment with 60 micromol/l evodiamine. Western blot indicated that evodiamine treatment decreased the expression of procaspase-8, procaspase-9, and procaspase-3 in lovo cells, accompanied by the activation of caspase-8, caspase-9, and caspase-3. However, the translocation of apoptosis-inducing factor and endonuclease G was not affected by evodiamine. Moreover, western blot assay also suggested that evodiamine-induced S phase arrest in lovo cells was associated with a marked decrease in the protein expression of cyclinA, cyclinA-dependent kinase 2, and cdc25c. In-vivo antineoplastic characteristics of evodiamine were examined in a human colon carcinoma lovo xenograft model and results showed that evodiamine increased the number of TUNEL-positive cells accompanied by the downregulated expression of procaspase-8, procaspase-9, and procaspase-3. In conclusion, these findings indicated that evodiamine could inhibit the in-vitro and in-vivo proliferation of human colon lovo cells by inducing caspase-dependent apoptosis and S phase arrest.

  2. R-Phycoerythrin Induces SGC-7901 Apoptosis by Arresting Cell Cycle at S Phase.

    PubMed

    Tan, Huixin; Gao, Shiyong; Zhuang, Yan; Dong, Yanhong; Guan, Wenhui; Zhang, Kun; Xu, Jian; Cui, Jingru

    2016-01-01

    R-Phycoerythrin (R-PE), one of the chemical constituents of red algae, could produce singlet oxygen upon excitation with the appropriate radiation and possibly be used in photodynamic therapy (PDT) for cancer. Documents reported that R-PE could inhibit cell proliferation in HepG2 and A549 cells, which was significative for cancer therapy. This is due to the fact that R-PE could kill cancer cells directly as well as by PDT. However, little is known about the cytotoxicity of R-PE to the SGC-7901 cell. In this study, it has been found that R-PE could inhibit SGC-7901 proliferation and induce cell apoptosis, which was achieved by arresting the SGC-7901 cell at S phase. CyclinA, CDK2 and CDC25A are proteins associated with the S phase, and it was found that R-PE could increase the expression of cyclin A protein and decrease the expression of CDK2 and CDC25A proteins. Thus, it was concluded that R-PE reduced the CDK2 protein activated through decreasing the CDC25A factor, which reduced the formation of Cyclin-CDK complex. The reduction of Cyclin-CDK complex made the SGC-7901 cells arrest at the S phase. Therefore, R-PE induced apoptosis by arresting the SGC-7901 cell at S phase was successful, which was achieved by the expression of the CDC25A protein, which reduced the CDK2 protein actived and the formation of Cyclin-CDK complex. PMID:27626431

  3. Cell cycle arrest in a model of colistin nephrotoxicity.

    PubMed

    Eadon, Michael T; Hack, Bradley K; Alexander, Jessy J; Xu, Chang; Dolan, M Eileen; Cunningham, Patrick N

    2013-10-01

    Colistin (polymixin E) is an antibiotic prescribed with resurging frequency for multidrug resistant gram negative bacterial infections. It is associated with nephrotoxicity in humans in up to 55% of cases. Little is known regarding genes involved in colistin nephrotoxicity. A murine model of colistin-mediated kidney injury was developed. C57/BL6 mice were administered saline or colistin at a dose of 16 mg/kg/day in 2 divided intraperitoneal doses and killed after either 3 or 15 days of colistin. After 15 days, mice exposed to colistin had elevated blood urea nitrogen (BUN), creatinine, and pathologic evidence of acute tubular necrosis and apoptosis. After 3 days, mice had neither BUN elevation nor substantial pathologic injury; however, urinary neutrophil gelatinase-associated lipocalin was elevated (P = 0.017). An Illumina gene expression array was performed on kidney RNA harvested 72 h after first colistin dose to identify differentially expressed genes early in drug treatment. Array data revealed 21 differentially expressed genes (false discovery rate < 0.1) between control and colistin-exposed mice, including LGALS3 and CCNB1. The gene signature was significantly enriched for genes involved in cell cycle proliferation. RT-PCR, immunoblot, and immunostaining validated the relevance of key genes and proteins. This murine model offers insights into the potential mechanism of colistin-mediated nephrotoxicity. Further studies will determine whether the identified genes play a causative or protective role in colistin-induced nephrotoxicity.

  4. Taxol induces concentration-dependent phosphatidylserine (PS) externalization and cell cycle arrest in ASTC-a-1 cells

    NASA Astrophysics Data System (ADS)

    Guo, Wen-jing; Chen, Tong-sheng

    2010-02-01

    Taxol (Paclitaxel) is an important natural product for the treatment of solid tumors. Different concentrations of taxol can trigger distinct effects on both the cellular microtubule network and biochemical pathways. Apoptosis induced by low concentrations (5-30 nM) of taxol was associated with mitotic arrest, alteration of microtubule dynamics and/or G2/M cell cycle arrest, whereas high concentrations of this drug (0.2-30 μM) caused significant microtubule damage, and was found recently to induce cytoplasm vacuolization in human lung adenocarcinoma (ASTC-a-1) cells. In present study, cell counting kit (CCK-8) assay, confocal microscope, and flow cytometry analysis were used to analyze the cell death form induced by 35 nM and 70 μM of taxol respectively in human lung adenocarcinoma (ASTC-a-1) cells. After treatment of 35 nM taxol for 48 h, the OD450 value was 0.80, and 35 nM taxol was found to induce dominantly cell death in apoptotic pathway such as phosphatidylserine (PS) externalization, G2/M phase arrest after treatment for 24 h, and nuclear fragmentation after treatment for 48 h. After 70 μM taxol treated the cell for 24 h, the OD450 value was 1.01, and 70 μM taxol induced cytoplasm vacuolization programmed cell death (PCD) and G2/M phase as well as the polyploidy phase arrest in paraptotic-like cell death. These findings imply that the regulated signaling pathway of cell death induced by taxol is dependent on taxol concentration in ASTC-a-1 cells.

  5. Dimethyl sulfoxide can initiate cell divisions of arrested callus protoplasts by promoting cortical microtubule assembly

    PubMed Central

    Hahne, Günther; Hoffmann, Franz

    1984-01-01

    A serious problem in the technology of plant cell culture is that isolated protoplasts from many species are reluctant to divide. We have succeeded in inducing consecutive divisions in a “naturally” arrested system—i.e., protoplasts from a hibiscus cell line, which do not divide under standard conditions—and in an artificially arrested system—i.e., colchicine-inhibited callus protoplasts of Nicotiana glutinosa, which do readily divide in the absence of colchicine. In both cases, the reinstallation of a net of cortical microtubules, which had been affected either by colchicine or by the protoplast isolation procedure, resulted in continuous divisions of the formerly arrested protoplasts. Several compounds known to support microtubule assembly in vitro were tested for their ability to promote microtubule assembly in vivo. Best results were obtained by addition of dimethyl sulfoxide to the culture medium. Unlimited amounts of callus could be produced with the dimethyl sulfoxide method from protoplasts which never developed a single callus in control experiments. Images PMID:16593508

  6. Numb contributes to renal fibrosis by promoting tubular epithelial cell cycle arrest at G2/M

    PubMed Central

    Zhu, Fengxin; Liu, Wei; Li, Tang; Wan, Jiao; Tian, Jianwei; Zhou, Zhanmei; Li, Hao; Liu, Youhua; Hou, Fan Fan; Nie, Jing

    2016-01-01

    Numb is a multifunctional protein involved in diverse cellular processes. However, the function of Numb in kidney remains unclear. Here, we reported that Numb is expressed in renal tubules and glomeruli in normal adult kidney. Numb expression was upregulated in fibrotic kidneys induced by unilateral ureteral obstruction (UUO) in mice as well as in human fibrotic kidney tissues. Numb overexpression in cultured proximal tubular cells increased the G2/M cell population and upregulated the expression of TGF-β1 and CTGF. Whereas, proximal tubule Numb knockout (PEPCK-Numb-KO) mice showed reduced G2/M arrest, decreased expression of TGF-β1 and CTGF, and attenuated fibrotic lesions due to either UUO or unilateral ischemia reperfusion nephropathy. Inhibiting p53 activity by pifithrin-β dramatically mitigated Numb-induced G2/M arrest, indicating that Numb potentiates G2/M arrest via stabilizing p53 protein. Together, these data suggest that Numb is a potential target for anti-fibrosis therapy. PMID:27016419

  7. Dimethyl sulfoxide can initiate cell divisions of arrested callus protoplasts by promoting cortical microtuble assembly

    SciTech Connect

    Hahne, G.; Hoffmann, F.

    1984-09-01

    A serious problem in the technology of plant cell culture is that isolated protoplasts from many species are reluctant to divide. We have succeeded in inducing consecutive divisions in a naturally arrested system i.e., protoplasts from a hibiscus cell line, which do not divide under standard conditions and in an artificially arrested system i.e., colchicine-inhibited callus protoplasts of Nicotiana glutinosa, which do readily divide in the absence of colchicine. In both cases, the reinstallation of a net of cortical microtubules, which had been affected either by colchicine or by the protoplast isolation procedure, resulted in continuous divisions of the formerly arrested protoplasts. Several compounds known to support microtubule assembly in vitro were tested for their ability to promote microtubule assembly in vivo. Best results were obtained by addition of dimethyl sulfoxide to the culture medium. Unlimited amounts of callus could be produced with the dimethyl sulfoxide method from protoplasts which never developed a single callus in control experiments. 30 references, 3 figures.

  8. Inorganic Pyrophosphatase Defects Lead to Cell Cycle Arrest and Autophagic Cell Death through NAD+ Depletion in Fermenting Yeast*

    PubMed Central

    Serrano-Bueno, Gloria; Hernández, Agustín; López-Lluch, Guillermo; Pérez-Castiñeira, José Román; Navas, Plácido; Serrano, Aurelio

    2013-01-01

    Inorganic pyrophosphatases are required for anabolism to take place in all living organisms. Defects in genes encoding these hydrolytic enzymes are considered inviable, although their exact nature has not been studied at the cellular and molecular physiology levels. Using a conditional mutant in IPP1, the Saccharomyces cerevisiae gene encoding the cytosolic soluble pyrophosphatase, we show that respiring cells arrest in S phase upon Ipp1p deficiency, but they remain viable and resume growth if accumulated pyrophosphate is removed. However, fermenting cells arrest in G1/G0 phase and suffer massive vacuolization and eventual cell death by autophagy. Impaired NAD+ metabolism is a major determinant of cell death in this scenario because demise can be avoided under conditions favoring accumulation of the oxidized pyridine coenzyme. These results posit that the mechanisms related to excess pyrophosphate toxicity in eukaryotes are dependent on the energy metabolism of the cell. PMID:23479727

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

    PubMed

    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. Berberine inhibits growth and induces G1 arrest and apoptosis in human cholangiocarcinoma QBC939 cells.

    PubMed

    He, Wei; Wang, Bin; Zhuang, Yun; Shao, Dong; Sun, Kewen; Chen, Jianping

    2012-01-01

    The chemotherapeutic approach using non-toxic natural products may be one of the strategies for the management of the cholangiocarcinoma. Here we report that in vitro treatment of human cholangiocarcinoma QBC939 cells with berberine, a naturally occurring isoquinoline alkaloid, decreased cell viability and induced cell death in a dose-dependent manner, which was associated with an increase in G1 arrest. Our western blot analysis showed that berberine-induced G1 cell cycle arrest was mediated through the increased expression of cyclin-dependent kinase inhibitors (Cdki) proteins (Cip1/p21 and Kip1/p27); a simultaneous decrease in Cdk2 and Cdk4 and cyclins D1, and reduced activity of the Cyclins-Cdk complex. In additional studies, treatment of QBC939 cells with different concentrations (10, 40, 80 μM) of berberine for 48 h resulted in a significant dose-dependent increase in apoptosis compared to the non-berberine-treated control, which was associated with an increased expression of pro-apoptotic protein Bax and decreased expression of anti-apoptotic proteins Bcl-2 and Bcl-xL. Together, this study for the first time identified berberine as a chemotherapeutic agent against human cholangiocarcinoma cells QBC939 cells in vitro. Further in vivo studies are required to determine whether berberine could be an effective chemotherapeutic agent for the management of cholangiocarcinoma.

  11. The marine-derived fungal metabolite, terrein, inhibits cell proliferation and induces cell cycle arrest in human ovarian cancer cells.

    PubMed

    Chen, Yi-Fei; Wang, Shu-Ying; Shen, Hong; Yao, Xiao-Fen; Zhang, Feng-Li; Lai, Dongmei

    2014-12-01

    The difficulties faced in the effective treatment of ovarian cancer are multifactorial, but are mainly associated with relapse and drug resistance. Cancer stem-like cells have been reported to be an important contributor to these hindering factors. In this study, we aimed to investigate the anticancer activities of a bioactive fungal metabolite, namely terrein, against the human epithelial ovarian cancer cell line, SKOV3, primary human ovarian cancer cells and ovarian cancer stem-like cells. Terrein was separated and purified from the fermentation metabolites of the marine sponge-derived fungus, Aspergillus terreus strain PF26. Its anticancer activities against ovarian cancer cells were investigated by cell proliferation assay, cell migration assay, cell apoptosis and cell cycle assays. The ovarian cancer stem-like cells were enriched and cultured in a serum-free in vitro suspension system. Terrein inhibited the proliferation of the ovarian cancer cells by inducing G2/M phase cell cycle arrest. The underlying mechanisms involved the suppression of the expression of LIN28, an important marker gene of stemness in ovarian cancer stem cells. Of note, our study also demonstrated the ability of terrein to inhibit the proliferation of ovarian cancer stem-like cells, in which the expression of LIN28 was also downregulated. Our findings reveal that terrein (produced by fermention) may prove to be a promising drug candidate for the treatment of ovarian cancer by inhibiting the proliferation of cancer stem-like cells.

  12. JAZ mediates G1 cell cycle arrest by interacting with and inhibiting E2F1

    PubMed Central

    Yang, Mingli; Wu, Song; Jia, Jinghua

    2011-01-01

    We discovered and reported JAZ as a unique dsRNA binding zinc finger protein that functions as a direct, positive regulator of p53 transcriptional activity to mediate G1 cell cycle arrest in a mechanism involving upregulation of the p53 target gene, p21. We now find that JAZ can also negatively regulate the cell cycle in a novel, p53-independent mechanism resulting from the direct interaction with E2F1, a key intermediate in regulating cell proliferation and tumor suppression. JAZ associates with E2F1's central DNA binding/dimerization region and its C-terminal transactivation domain. Functionally, JAZ represses E2F1 transcriptional activity in association with repression of cyclin A expression and inhibition of G1/S transition. This mechanism involves JAZ-mediated inhibition of E2F1's specific DNA binding activity. JAZ directly binds E2F1 in vitro in a dsRNA-independent manner, and JAZ's dsRNA binding ZF domains, which are necessary for localizing JAZ to the nucleus, are required for repression of transcriptional activity in vivo. Importantly for specificity, siRNA-mediated “knockdown” of endogenous JAZ increases E2F transcriptional activity and releases cells from G1 arrest, indicating a necessary role for JAZ in this transition. Although JAZ can directly inhibit E2F1 activity independently of p53, if functional p53 is expressed, JAZ may exert a more potent inhibition of cell cycle following growth factor withdrawal. Therefore, JAZ plays a dual role in cell cycle regulation by both repressing E2F1 transcriptional activity and activating p53 to facilitate efficient growth arrest in response to cellular stress, which may potentially be exploited therapeutically for tumor growth inhibition. PMID:21715977

  13. Uncoupling between Phenotypic Senescence and Cell Cycle Arrest in Aging p21-Deficient Fibroblasts

    PubMed Central

    Dulić, Vjekoslav; Beney, Georges-Edouard; Frebourg, Guillaume; Drullinger, Linda F.; Stein, Gretchen H.

    2000-01-01

    Irreversible G1 arrest in senescent human fibroblasts is mediated by two inhibitors of cyclin-dependent kinases (Cdks), p21Cip1/SDI1/WAF1 and p16Ink4A. To determine the physiological and molecular events that specifically require p21, we studied senescence in human diploid fibroblasts expressing the human papillomavirus type 16 E6 oncogene, which confers low p21 levels via enhanced p53 degradation. We show that in late-passage E6 cells, high Cdk activity drives the cell cycle, but population expansion is slowed down by crisis-like events, probably owing to defective cell cycle checkpoints. At the end of lifespan, terminal-passage E6 cells exhibited several aspects of the senescent phenotype and accumulated unphosphorylated pRb and p16. However, both replication and cyclin-Cdk2 kinase activity were still not blocked, demonstrating that phenotypic and replicative senescence are uncoupled in the absence of normal p21 levels. At this stage, E6 cells also failed to upregulate p27 and inactivate cyclin-Cdk complexes in response to serum deprivation. Eventually, irreversible G1 arrest occurred coincident with inactivation of cyclin E-Cdk2 owing to association with p21. Similarly, when p21−/− mouse embryo fibroblasts reached the end of their lifespan, they had the appearance of senescent cells yet, in contrast to their wild-type counterparts, they were deficient in downregulating bromodeoxyuridine incorporation, cyclin E- and cyclin A-Cdk2 activity, and inhibiting pRb hyperphosphorylation. These data support the model that the critical event ensuring G1 arrest in senescence is p21-dependent Cdk inactivation, while other aspects of senescent phenotype appear to occur independently of p21. PMID:10958672

  14. Aspartate Rescues S-phase Arrest Caused by Suppression of Glutamine Utilization in KRas-driven Cancer Cells.

    PubMed

    Patel, Deven; Menon, Deepak; Bernfeld, Elyssa; Mroz, Victoria; Kalan, Sampada; Loayza, Diego; Foster, David A

    2016-04-22

    During G1-phase of the cell cycle, normal cells respond first to growth factors that indicate that it is appropriate to divide and then later in G1 to the presence of nutrients that indicate sufficient raw material to generate two daughter cells. Dividing cells rely on the "conditionally essential" amino acid glutamine (Q) as an anaplerotic carbon source for TCA cycle intermediates and as a nitrogen source for nucleotide biosynthesis. We previously reported that while non-transformed cells arrest in the latter portion of G1 upon Q deprivation, mutant KRas-driven cancer cells bypass the G1 checkpoint, and instead, arrest in S-phase. In this study, we report that the arrest of KRas-driven cancer cells in S-phase upon Q deprivation is due to the lack of deoxynucleotides needed for DNA synthesis. The lack of deoxynucleotides causes replicative stress leading to activation of the ataxia telangiectasia and Rad3-related protein (ATR)-mediated DNA damage pathway, which arrests cells in S-phase. The key metabolite generated from Q utilization was aspartate, which is generated from a transaminase reaction whereby Q-derived glutamate is converted to α-ketoglutarate with the concomitant conversion of oxaloacetate to aspartate. Aspartate is a critical metabolite for both purine and pyrimidine nucleotide biosynthesis. This study identifies the molecular basis for the S-phase arrest caused by Q deprivation in KRas-driven cancer cells that arrest in S-phase in response to Q deprivation. Given that arresting cells in S-phase sensitizes cells to apoptotic insult, this study suggests novel therapeutic approaches to KRas-driven cancers.

  15. Notch signaling indirectly promotes chondrocyte hypertrophy via regulation of BMP signaling and cell cycle arrest

    PubMed Central

    Shang, Xifu; Wang, Jinwu; Luo, Zhengliang; Wang, Yongjun; Morandi, Massimo M.; Marymont, John V.; Hilton, Matthew J.; Dong, Yufeng

    2016-01-01

    Cell cycle regulation is critical for chondrocyte differentiation and hypertrophy. Recently we identified the Notch signaling pathway as an important regulator of chondrocyte proliferation and differentiation during mouse cartilage development. To investigate the underlying mechanisms, we assessed the role for Notch signaling regulation of the cell cycle during chondrocyte differentiation. Real-time RT-PCR data showed that over-expression of the Notch Intracellular Domain (NICD) significantly induced the expression of p57, a cell cycle inhibitor, in chondrocytes. Flow cytometric analyses further confirmed that over-expression of NICD in chondrocytes enhances the G0/G1 cell cycle transition and cell cycle arrest. In contrast, treatment of chondrocytes with the Notch inhibitor, DAPT, decreased both endogenous and BMP2-induced SMAD 1/5/8 phosphorylation and knockdown of SMAD 1/5/8 impaired NICD-induced chondrocyte differentiation and p57 expression. Co-immunoprecipitation using p-SMAD 1/5/8 and NICD antibodies further showed a strong interaction of these proteins during chondrocyte maturation. Finally, RT-PCR and Western blot results revealed a significant reduction in the expression of the SMAD-related phosphatase, PPM1A, following NICD over-expression. Taken together, our results demonstrate that Notch signaling induces cell cycle arrest and thereby initiates chondrocyte hypertrophy via BMP/SMAD-mediated up-regulation of p57. PMID:27146698

  16. How Trypanosoma cruzi handles cell cycle arrest promoted by camptothecin, a topoisomerase I inhibitor.

    PubMed

    Zuma, Aline Araujo; Mendes, Isabela Cecília; Reignault, Lissa Catherine; Elias, Maria Carolina; de Souza, Wanderley; Machado, Carlos Renato; Motta, Maria Cristina M

    2014-02-01

    The protozoan Trypanosoma cruzi is the etiological agent of Chagas disease, which affects approximately 8 million people in Latin America. This parasite contains a single nucleus and a kinetoplast, which harbors the mitochondrial DNA (kDNA). DNA topoisomerases act during replication, transcription and repair and modulate DNA topology by reverting supercoiling in the DNA double-strand. In this work, we evaluated the effects promoted by camptothecin, a topoisomerase I inhibitor that promotes protozoan proliferation impairment, cell cycle arrest, ultrastructure alterations and DNA lesions in epimastigotes of T. cruzi. The results showed that inhibition of cell proliferation was reversible only at the lowest drug concentration (1μM) used. The unpacking of nuclear heterochromatin and mitochondrion swelling were the main ultrastructural modifications observed. Inhibition of parasite proliferation also led to cell cycle arrest, which was most likely caused by nuclear DNA lesions. Following camptothecin treatment, some of the cells restored their DNA, whereas others entered early apoptosis but did not progress to late apoptosis, indicating that the protozoa stay alive in a "senescence-like" state. This programmed cell death may be associated with a decrease in mitochondrial membrane potential and an increase in the production of reactive oxygen species. Taken together, these results indicate that the inhibition of T. cruzi proliferation is related to events capable of affecting cell cycle, DNA organization and mitochondrial activity. PMID:24530483

  17. Downregulation of FOXP1 Inhibits Cell Proliferation in Hepatocellular Carcinoma by Inducing G1/S Phase Cell Cycle Arrest

    PubMed Central

    Wang, Xin; Sun, Ji; Cui, Meiling; Zhao, Fangyu; Ge, Chao; Chen, Taoyang; Yao, Ming; Li, Jinjun

    2016-01-01

    Forkhead box P1 (FOXP1) belongs to a family of winged-helix transcription factors that are involved in the processes of cellular proliferation, differentiation, metabolism, and longevity. FOXP1 can affect cell proliferation and migratory ability in hepatocellular carcinoma (HCC) in vitro. However, little is known about the mechanism of FOXP1 in the proliferation of HCC cells. This study aimed to further explore the function of FOXP1 on the proliferation of HCC cells as well as the relevant mechanism involved. Western blot analysis, tumor xenograft models, and flow cytometry analysis were performed to elucidate the function of FOXP1 in the regulation of cell proliferation in human HCC. We observed that silencing FOXP1 significantly suppressed the growth ability of HCC cells both in vitro and in vivo. In addition, knockdown of FOXP1 induced G1/S phase arrest, and the expression of total and phosphorylated Rb (active type) as well as the levels of E2F1 were markedly decreased at 24 h; however, other proteins, including cyclin-dependent kinase (CDK) 4 and 6 and cyclin D1 did not show noticeable changes. In conclusion, downregulation of FOXP1 inhibits cell proliferation in hepatocellular carcinoma by inducing G1/S phase cell cycle arrest, and the decrease in phosphorylated Rb is the main contributor to this G1/S phase arrest. PMID:27618020

  18. Downregulation of FOXP1 Inhibits Cell Proliferation in Hepatocellular Carcinoma by Inducing G1/S Phase Cell Cycle Arrest.

    PubMed

    Wang, Xin; Sun, Ji; Cui, Meiling; Zhao, Fangyu; Ge, Chao; Chen, Taoyang; Yao, Ming; Li, Jinjun

    2016-01-01

    Forkhead box P1 (FOXP1) belongs to a family of winged-helix transcription factors that are involved in the processes of cellular proliferation, differentiation, metabolism, and longevity. FOXP1 can affect cell proliferation and migratory ability in hepatocellular carcinoma (HCC) in vitro. However, little is known about the mechanism of FOXP1 in the proliferation of HCC cells. This study aimed to further explore the function of FOXP1 on the proliferation of HCC cells as well as the relevant mechanism involved. Western blot analysis, tumor xenograft models, and flow cytometry analysis were performed to elucidate the function of FOXP1 in the regulation of cell proliferation in human HCC. We observed that silencing FOXP1 significantly suppressed the growth ability of HCC cells both in vitro and in vivo. In addition, knockdown of FOXP1 induced G1/S phase arrest, and the expression of total and phosphorylated Rb (active type) as well as the levels of E2F1 were markedly decreased at 24 h; however, other proteins, including cyclin-dependent kinase (CDK) 4 and 6 and cyclin D1 did not show noticeable changes. In conclusion, downregulation of FOXP1 inhibits cell proliferation in hepatocellular carcinoma by inducing G1/S phase cell cycle arrest, and the decrease in phosphorylated Rb is the main contributor to this G1/S phase arrest. PMID:27618020

  19. Induction of Apoptosis and Cell Cycle Arrest in Human Colorectal Carcinoma by Litchi Seed Extract

    PubMed Central

    Hsu, Chih-Ping; Lin, Chih-Cheng; Huang, Chiu-Chen; Lin, Yi-Hsien; Chou, Jyh-Ching; Tsia, Yu-Ting; Su, Jhih-Rou; Chung, Yuan-Chiang

    2012-01-01

    The Litchi (Litchi chinensis) fruit products possess rich amounts of flavanoids and proanthocyanidins. Its pericarp has been shown to inhibit breast and liver cancer cell growth. However, the anticolorectal cancer effect of Litchi seed extract has not yet been reported. In this study, the effects of polyphenol-rich Litchi seed ethanol extract (LCSP) on the proliferation, cell cycle, and apoptosis of two colorectal cancer cell lines Colo320DM and SW480 were examined. The results demonstrated that LCSP significantly induced apoptotic cell death in a dose-dependent manner and arrested cell cycle in G2/M in colorectal carcinoma cells. LCSP also suppressed cyclins and elevated the Bax : Bcl-2 ratio and caspase 3 activity. This study provides in vitro evidence that LCSP serves as a potential chemopreventive agent for colorectal cancer. PMID:23093841

  20. SB225002 Induces Cell Death and Cell Cycle Arrest in Acute Lymphoblastic Leukemia Cells through the Activation of GLIPR1.

    PubMed

    de Vasconcellos, Jaíra Ferreira; Laranjeira, Angelo Brunelli Albertoni; Leal, Paulo C; Bhasin, Manoj K; Zenatti, Priscila Pini; Nunes, Ricardo J; Yunes, Rosendo A; Nowill, Alexandre E; Libermann, Towia A; Zerbini, Luiz Fernando; Yunes, José Andrés

    2015-01-01

    Acute Lymphoblastic Leukemia (ALL) is the most frequent childhood malignancy. In the effort to find new anti-leukemic agents, we evaluated the small drug SB225002 (N-(2-hydroxy-4-nitrophenyl)-N'-(2-bromophenyl)urea). Although initially described as a selective antagonist of CXCR2, later studies have identified other cellular targets for SB225002, with potential medicinal use in cancer. We found that SB225002 has a significant pro-apoptotic effect against both B- and T-ALL cell lines. Cell cycle analysis demonstrated that treatment with SB225002 induces G2-M cell cycle arrest. Transcriptional profiling revealed that SB225002-mediated apoptosis triggered a transcriptional program typical of tubulin binding agents. Network analysis revealed the activation of genes linked to the JUN and p53 pathways and inhibition of genes linked to the TNF pathway. Early cellular effects activated by SB225002 included the up-regulation of GLIPR1, a p53-target gene shown to have pro-apoptotic activities in prostate and bladder cancer. Silencing of GLIPR1 in B- and T-ALL cell lines resulted in increased resistance to SB225002. Although SB225002 promoted ROS increase in ALL cells, antioxidant N-Acetyl Cysteine pre-treatment only modestly attenuated cell death, implying that the pro-apoptotic effects of SB225002 are not exclusively mediated by ROS. Moreover, GLIPR1 silencing resulted in increased ROS levels both in untreated and SB225002-treated cells. In conclusion, SB225002 induces cell cycle arrest and apoptosis in different B- and T-ALL cell lines. Inhibition of tubulin function with concurrent activation of the p53 pathway, in particular, its downstream target GLIPR1, seems to underlie the anti-leukemic effect of SB225002.

  1. SB225002 Induces Cell Death and Cell Cycle Arrest in Acute Lymphoblastic Leukemia Cells through the Activation of GLIPR1

    PubMed Central

    Leal, Paulo C.; Bhasin, Manoj K.; Zenatti, Priscila Pini; Nunes, Ricardo J.; Yunes, Rosendo A.; Nowill, Alexandre E.; Libermann, Towia A.; Zerbini, Luiz Fernando; Yunes, José Andrés

    2015-01-01

    Acute Lymphoblastic Leukemia (ALL) is the most frequent childhood malignancy. In the effort to find new anti-leukemic agents, we evaluated the small drug SB225002 (N-(2-hydroxy-4-nitrophenyl)-N’-(2-bromophenyl)urea). Although initially described as a selective antagonist of CXCR2, later studies have identified other cellular targets for SB225002, with potential medicinal use in cancer. We found that SB225002 has a significant pro-apoptotic effect against both B- and T-ALL cell lines. Cell cycle analysis demonstrated that treatment with SB225002 induces G2-M cell cycle arrest. Transcriptional profiling revealed that SB225002-mediated apoptosis triggered a transcriptional program typical of tubulin binding agents. Network analysis revealed the activation of genes linked to the JUN and p53 pathways and inhibition of genes linked to the TNF pathway. Early cellular effects activated by SB225002 included the up-regulation of GLIPR1, a p53-target gene shown to have pro-apoptotic activities in prostate and bladder cancer. Silencing of GLIPR1 in B- and T-ALL cell lines resulted in increased resistance to SB225002. Although SB225002 promoted ROS increase in ALL cells, antioxidant N-Acetyl Cysteine pre-treatment only modestly attenuated cell death, implying that the pro-apoptotic effects of SB225002 are not exclusively mediated by ROS. Moreover, GLIPR1 silencing resulted in increased ROS levels both in untreated and SB225002-treated cells. In conclusion, SB225002 induces cell cycle arrest and apoptosis in different B- and T-ALL cell lines. Inhibition of tubulin function with concurrent activation of the p53 pathway, in particular, its downstream target GLIPR1, seems to underlie the anti-leukemic effect of SB225002. PMID:26302043

  2. Raman spectrum reveals the cell cycle arrest of Triptolide-induced leukemic T-lymphocytes apoptosis

    NASA Astrophysics Data System (ADS)

    Zhang, Daosen; Feng, Yanyan; Zhang, Qinnan; Su, Xin; Lu, Xiaoxu; Liu, Shengde; Zhong, Liyun

    2015-04-01

    Triptolide (TPL), a traditional Chinese medicine extract, possesses anti-inflammatory and anti-tumor properties. Though some research results have implicated that Triptolide (TPL) can be utilized in the treatment of leukemia, it remains controversial about the mechanism of TPL-induced leukemic T-lymphocytes apoptosis. In this study, combining Raman spectroscopic data, principal component analysis (PCA) and atomic force microscopy (AFM) imaging, both the biochemical changes and morphological changes during TPL-induced cell apoptosis were presented. In contrast, the corresponding data during Daunorubicin (DNR)-induced cell apoptosis was also exhibited. The obtained results showed that Raman spectral changes during TPL-induced cell apoptosis were greatly different from DNR-induced cell apoptosis in the early stage of apoptosis but revealed the high similarity in the late stage of apoptosis. Moreover, above Raman spectral changes were respectively consistent with the morphological changes of different stages during TPL-induced apoptosis or DNR-induced apoptosis, including membrane shrinkage and blebbing, chromatin condensation and the formation of apoptotic bodies. Importantly, it was found that Raman spectral changes with TPL-induced apoptosis or DNR-induced apoptosis were respectively related with the cell cycle G1 phase arrest or G1 and S phase arrest.

  3. Platelet-activating factor induces cell cycle arrest and disrupts the DNA damage response in mast cells

    PubMed Central

    Puebla-Osorio, N; Damiani, E; Bover, L; Ullrich, S E

    2015-01-01

    Platelet-activating factor (PAF) is a potent phospholipid modulator of inflammation that has diverse physiological and pathological functions. Previously, we demonstrated that PAF has an essential role in ultraviolet (UV)-induced immunosuppression and reduces the repair of damaged DNA, suggesting that UV-induced PAF is contributing to skin cancer initiation by inducing immune suppression and also affecting a proper DNA damage response. The exact role of PAF in modulating cell proliferation, differentiation or transformation is unclear. Here, we investigated the mechanism(s) by which PAF affects the cell cycle and impairs early DNA damage response. PAF arrests proliferation in transformed and nontransformed human mast cells by reducing the expression of cyclin-B1 and promoting the expression of p21. PAF-treated cells show a dose-dependent cell cycle arrest mainly at G2–M, and a decrease in the DNA damage response elements MCPH1/BRIT-1 and ataxia telangiectasia and rad related (ATR). In addition, PAF disrupts the localization of p-ataxia telangiectasia mutated (p-ATM), and phosphorylated-ataxia telangiectasia and rad related (p-ATR) at the site of DNA damage. Whereas the potent effect on cell cycle arrest may imply a tumor suppressor activity for PAF, the impairment of proper DNA damage response might implicate PAF as a tumor promoter. The outcome of these diverse effects may be dependent on specific cues in the microenvironment. PMID:25950475

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

    PubMed Central

    Strangward, Patrick; Dandamudi, Durga B.; Coles, Jonathan A.; Villegas-Mendez, Ana; Gallego-Delgado, Julio; van Rooijen, Nico; Zindy, Egor; Rodriguez, Ana; Brewer, James M.; Couper, Kevin N.; Dustin, Michael L.

    2015-01-01

    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. PMID:26562533

  5. CDK4/6 inhibition induces epithelial cell cycle arrest and ameliorates acute kidney injury

    PubMed Central

    DiRocco, Derek P.; Bisi, John; Roberts, Patrick; Strum, Jay; Wong, Kwok-Kin; Sharpless, Norman

    2013-01-01

    Acute kidney injury (AKI) is common and urgently requires new preventative therapies. Expression of a cyclin-dependent kinase (CDK) inhibitor transgene protects against AKI, suggesting that manipulating the tubular epithelial cell cycle may be a viable therapeutic strategy. Broad spectrum small molecule CDK inhibitors are protective in some kidney injury models, but these have toxicities and epithelial proliferation is eventually required for renal repair. Here, we tested a well-tolerated, novel and specific small molecule inhibitor of CDK4 and CDK6, PD 0332991, to investigate the effects of transient cell cycle inhibition on epithelial survival in vitro and kidney injury in vivo. We report that CDK4/6 inhibition induced G0/G1 cycle arrest in cultured human renal proximal tubule cells (hRPTC) at baseline and after injury. Induction of transient G0/G1 cycle arrest through CDK4/6 inhibition protected hRPTC from DNA damage and caspase 3/7 activation following exposure to the nephrotoxins cisplatin, etoposide, and antimycin A. In vivo, mice treated with PD 0332991 before ischemia-reperfusion injury (IRI) exhibited dramatically reduced epithelial progression through S phase 24 h after IRI. Despite reduced epithelial proliferation, PD 0332991 ameliorated kidney injury as reflected by improved serum creatinine and blood urea nitrogen levels 24 h after injury. Inflammatory markers and macrophage infiltration were significantly decreased in injured kidneys 3 days following IRI. These results indicate that induction of proximal tubule cell cycle arrest with specific CDK4/6 inhibitors, or “pharmacological quiescence,” represents a novel strategy to prevent AKI. PMID:24338822

  6. CDK4/6 inhibition induces epithelial cell cycle arrest and ameliorates acute kidney injury.

    PubMed

    DiRocco, Derek P; Bisi, John; Roberts, Patrick; Strum, Jay; Wong, Kwok-Kin; Sharpless, Norman; Humphreys, Benjamin D

    2014-02-15

    Acute kidney injury (AKI) is common and urgently requires new preventative therapies. Expression of a cyclin-dependent kinase (CDK) inhibitor transgene protects against AKI, suggesting that manipulating the tubular epithelial cell cycle may be a viable therapeutic strategy. Broad spectrum small molecule CDK inhibitors are protective in some kidney injury models, but these have toxicities and epithelial proliferation is eventually required for renal repair. Here, we tested a well-tolerated, novel and specific small molecule inhibitor of CDK4 and CDK6, PD 0332991, to investigate the effects of transient cell cycle inhibition on epithelial survival in vitro and kidney injury in vivo. We report that CDK4/6 inhibition induced G0/G1 cycle arrest in cultured human renal proximal tubule cells (hRPTC) at baseline and after injury. Induction of transient G0/G1 cycle arrest through CDK4/6 inhibition protected hRPTC from DNA damage and caspase 3/7 activation following exposure to the nephrotoxins cisplatin, etoposide, and antimycin A. In vivo, mice treated with PD 0332991 before ischemia-reperfusion injury (IRI) exhibited dramatically reduced epithelial progression through S phase 24 h after IRI. Despite reduced epithelial proliferation, PD 0332991 ameliorated kidney injury as reflected by improved serum creatinine and blood urea nitrogen levels 24 h after injury. Inflammatory markers and macrophage infiltration were significantly decreased in injured kidneys 3 days following IRI. These results indicate that induction of proximal tubule cell cycle arrest with specific CDK4/6 inhibitors, or "pharmacological quiescence," represents a novel strategy to prevent AKI.

  7. Protein-binding, cytotoxicity in vitro and cell cycle arrest of ruthenium(II) polypyridyl complexes

    NASA Astrophysics Data System (ADS)

    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.

  8. De novo formation of centrosomes in vertebrate cells arrested during S phase.

    PubMed

    Khodjakov, Alexey; Rieder, Conly L; Sluder, Greenfield; Cassels, Grisel; Sibon, Ody; Wang, Chuo-Lung

    2002-09-30

    The centrosome usually replicates in a semiconservative fashion, i.e., new centrioles form in association with preexisting "maternal" centrioles. De novo formation of centrioles has been reported for a few highly specialized cell types but it has not been seen in vertebrate somatic cells. We find that when centrosomes are completely destroyed by laser microsurgery in CHO cells arrested in S phase by hydroxyurea, new centrosomes form by de novo assembly. Formation of new centrosomes occurs in two steps: approximately 5-8 h after ablation, clouds of pericentriolar material (PCM) containing gamma-tubulin and pericentrin appear in the cell. By 24 h, centrioles have formed inside of already well-developed PCM clouds. This de novo pathway leads to the formation of a random number of centrioles (2-14 per cell). Although clouds of PCM consistently form even when microtubules are completely disassembled by nocodazole, the centrioles are not assembled under these conditions.

  9. Cell cycle arrest and apoptogenic properties of opium alkaloids noscapine and papaverine on breast cancer stem cells.

    PubMed

    Sajadian, Saharolsadat; Vatankhah, Melody; Majdzadeh, Maryam; Kouhsari, Shide Montaser; Ghahremani, Mohammad Hossein; Ostad, Seyed Nasser

    2015-01-01

    Previous report of the vast effectiveness of opium derivatives in cancer therapy is leading us to see possible effects of these derivatives on cancer stem cells in order to find new agent for cancer therapy. In this study, cells were stained for CSC markers and sorted by magnetic beads. CSCs exhibit the characteristic CD44(+)/CD24(-/low)/ESA(+) phenotype. Noscapine and papaverine (alkaloids) showed anti-proliferative activity on MCF-7 and MDA-MB-231 cell lines. It was observed that noscapine has more cytotoxic effect on CSC derived from both cell lines compared with their parental cells. Papaverine has more cytotoxic effect on MCF-7 CSCs in comparison with parental cells, while CSCs population of MDA-MB-231 is more resistant to papaverine compared with MDA-MB-231 cells. Noscapine enhances apoptosis in MDA-MB-231 CSCs more than parent cells, while in MCF-7 CSCs the apoptosis is less than parent cells. Our results show that papverine is less active in terms of apoptotic effect on CSCs in both cell lines. Moreover, noscapine arrests MCF-7 and MDA-MB-231 CSCs cell cycle at G2/M phase, while papverine arrests cell cycle at G0/G1 phase. It was suggested different mechanism for apoptotic cytotoxicity. The results of this study show possible specific effects of noscapine on these breast cell lines CSCs. PMID:25980655

  10. Ethanol extract of Innotus obliquus (Chaga mushroom) induces G1 cell cycle arrest in HT-29 human colon cancer cells

    PubMed Central

    Lee, Hyun Sook; Kim, Eun Ji

    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 cultured in the presence of 2.5 - 10 µg/mL of EEIO, and analyzed the cell cycle arrest by flow cytometry and the cell cycle controlling protein expression by Western blotting. RESULTS Treatment cells with 2.5 - 10 µg/mL of EEIO reduced viable HT-29 cell numbers and DNA synthesis, increased the percentage of cells in G1 phase, decreased protein expression of CDK2, CDK4, and cyclin D1, increased expression of p21, p27, and p53, and inhibited phosphorylation of Rb and E2F1 expression. Among I. obliquus fractions, fraction 2 (fractionated by dichloromethane from EEIO) showed the same effect as EEIO treatment on cell proliferation and cell cycle-related protein levels. CONCLUSIONS These results demonstrate that fraction 2 is the major fraction that induces G1 arrest and inhibits cell proliferation, suggesting I. obliquus could be used as a natural anti-cancer ingredient in the food and/or pharmaceutical industry. PMID:25861415

  11. Scorpion (Androctonus bicolor) venom exhibits cytotoxicity and induces cell cycle arrest and apoptosis in breast and colorectal cancer cell lines

    PubMed Central

    Al-Asmari, Abdulrahman K.; Riyasdeen, Anvarbatcha; Abbasmanthiri, Rajamohamed; Arshaduddin, Mohammed; Al-Harthi, Fahad Ali

    2016-01-01

    Objectives: The defective apoptosis is believed to play a major role in the survival and proliferation of neoplastic cells. Hence, the induction of apoptosis in cancer cells is one of the targets for cancer treatment. Researchers are considering scorpion venom as a potent natural source for cancer treatment because it contains many bioactive compounds. The main objective of the current study is to evaluate the anticancer property of Androctonus bicolor scorpion venom on cancer cells. Materials and Methods: Scorpions were milked by electrical stimulation of telsons and lyophilized. The breast (MDA-MB-231) and colorectal (HCT-8) cancer cells were maintained in appropriate condition. The venom cytotoxicity was assessed by 3-(4,5-di-methylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide assay, and the cellular and nuclear changes were studied with propidium iodide and 4’,6-diamidino-2-phenylindole stain, respectively. The cell cycle arrest was examined using muse cell analyzer. Results: The A. bicolor venom exerted cytotoxic effects on MDA-MB-231 and HCT-8 cells in a dose- and duration-dependent manner and induced apoptotic cell death. The treatment with this venom arrests the cancer cells in G0/G1 phase of cell cycle. Conclusions: The venom selectively induces the rate of apoptosis in MDA-MB-231 and HCT-8 cells as reflected by morphological and cell cycle studies. To the best of our knowledge, this is the first scientific evidence demonstrating the induction of apoptosis and cell cycle arrest by A. bicolor scorpion venom. PMID:27721540

  12. Downregulation of cell cycle-related proteins in ovarian cancer line and cell cycle arrest induced by microRNA

    PubMed Central

    Yuan, Jian-Mei; Shi, Xue-Jun; Sun, Ping; Liu, Jun-Xia; Wang, Wei; Li, Ming; Ling, Feng-Yu

    2015-01-01

    Objective: The effect of miR-449 and miR-34 on the growth, cell cycle and target gene expressions of ovarian cancer cell line SKOV3 and SKOV3-ipl was discussed. Method: Real-time quantitative reverse transcription PCR was employed to detect the expressions of miR-449a/b and miR-34b, c in SKOV3 and SKOV3-ipl cells. The two miRNAs were successfully expressed in SKOV3-ipl cells by transfection. The variations in cell growth rate and cell cycle were determined by MTS assay and flow cytometry, respectively. The expressions of cell cycle-related proteins were detected by Western Blot. Results: miR-449b and miR-34c induced the decline of the adhesiveness of SKOV3-ipl cells by 20%-30%. The number of cells arrested in G1-phase increased and the number of cells arrested in S-phase decreased significantly. The cell cycle-related proteins CDK6 and CDC254 were downregulated. miR-449b caused the expression of CDK6 and CDC25A to decrease. After the co-transfection with miR-449b and miR-34c, the relevant proteins were downregulated more significantly. The expressions of CDK6, CDC25A and cyclin A were decreased significantly. Conclusion: miR-449b and miR-34c can induce cell cycle arrest in SKOV3-ipl cells and the downregulation of CDK6, CDC25A and cyclin A. PMID:26770455

  13. Does cell cycle arrest occur in plant under solar UV-B radiation?

    PubMed

    Jiang, Lei; Wang, Yan; Björn, Lars Olof; Li, Shaoshan

    2011-06-01

    UV-B radiation (280-315 nm) is an integral part of solar radiation and has many harmful effects on plant growth and development. However, the molecular mechanism for the inhibition of plant growth by UV-B remains largely unknown. UV-B radiation induces various responses such as growth inhibition, DNA damage and changes of gene expression. Recently, by using synchronous root tip culture, we found that UV-B modulates the expression of cell cycle regulatory genes through DNA damage. Western blotting analysis revealed that UV-B induced G1-to-S arrest did not correlate with the protein abundance of CDKB1;1 and CYCD3;1 gene regulating proteins, but may with the posttranslational control. We extended the expression analysis of cell cycle related genes based on the published microarray data and the results strengthen our assumption that cell cycle arrest could occur in plant under solar UV-B radiation. Further study is needed to elucidate the relationship between cell cycle regulation and protective pathway induced by low dose of UV-B radiation fundamental molecular mechanism for how plants respond to solar UV-B radiation.

  14. In Vitro Anti-Neuroblastoma Activity of Thymoquinone Against Neuro-2a Cells via Cell-cycle Arrest.

    PubMed

    Paramasivam, Arumugam; Raghunandhakumar, Subramanian; Priyadharsini, Jayaseelan Vijayashree; Jayaraman, Gopalswamy

    2015-01-01

    We have recently shown that thymoquinone (TQ) has a potent cytotoxic effect and induces apoptosis via caspase-3 activation with down-regulation of XIAP in mouse neuroblastoma (Neuro-2a) cells. Interestingly, our results showed that TQ was significantly more cytotoxic towards Neuro-2a cells when compared with primary normal neuronal cells. In this study, the effects of TQ on cell-cycle regulation and the mechanisms that contribute to this effect were investigated using Neuro-2a cells. Cell-cycle analysis performed by flow cytometry revealed cell-cycle arrest at G2/M phase and a significant increase in the accumulation of TQ-treated cells at sub-G1 phase, indicating induction of apoptosis by the compound. Moreover, TQ increased the expression of p53, p21 mRNA and protein levels, whereas it decreased the protein expression of PCNA, cyclin B1 and Cdc2 in a dose- dependent manner. Our finding suggests that TQ could suppress cell growth and cell survival via arresting the cell-cycle in the G2/M phase and inducing apoptosis of neuroblastoma cells.

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

    PubMed Central

    Ren, Bao-Jun; Zhou, Zhi-Wei; Zhu, Da-Jian; Ju, Yong-Le; Wu, Jin-Hao; Ouyang, Man-Zhao; Chen, Xiao-Wu; Zhou, Shu-Feng

    2015-01-01

    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. PMID:26729093

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

    SciTech Connect

    Huang, Li-Wen; Hsieh, Bau-Shan; Cheng, Hsiao-Ling; Hu, Yu-Chen; Chang, Wen-Tsan; Chang, Kee-Lung

    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

  17. Extracts of centipede Scolopendra subspinipes mutilans induce cell cycle arrest and apoptosis in A375 human melanoma cells.

    PubMed

    Ma, Weina; Liu, Rui; Qi, Junpeng; Zhang, Yanmin

    2014-07-01

    Extracts from the centipede Scolopendra genus, have been used in traditional medicine for the treatment of various diseases and have been found to exhibit anticancer activity in tumor cells. To investigate the potential and associated antitumor mechanism of alcohol extracts of the centipede Scolopendra subspinipes mutilans (AECS), cell viability, cell cycle and cell apoptosis were studied and the results revealed that AECS inhibits A375 cell proliferation in a dose- and time-dependent manner. In addition, AECS was found to arrest the cell cycle of A375 cells at the S phase, which was accompanied by a marked increase in the protein levels of cyclin E and a decrease in the protein levels of cyclin D1. In a cell culture system, AECS markedly induced the apoptosis of A375 cells, which was closely associated with the effects on the Bcl-2 family, whereby decreased Bcl-2 and increased Bak, Bax and Bad expression levels were observed. The underlying mechanism of AECS inhibiting A375 cell proliferation was associated with the induction of cell cycle arrest and apoptosis, indicating that AECS may present as a potential therapeutic agent for administration in human melanoma cancer intervention.

  18. Extracts of centipede Scolopendra subspinipes mutilans induce cell cycle arrest and apoptosis in A375 human melanoma cells.

    PubMed

    Ma, Weina; Liu, Rui; Qi, Junpeng; Zhang, Yanmin

    2014-07-01

    Extracts from the centipede Scolopendra genus, have been used in traditional medicine for the treatment of various diseases and have been found to exhibit anticancer activity in tumor cells. To investigate the potential and associated antitumor mechanism of alcohol extracts of the centipede Scolopendra subspinipes mutilans (AECS), cell viability, cell cycle and cell apoptosis were studied and the results revealed that AECS inhibits A375 cell proliferation in a dose- and time-dependent manner. In addition, AECS was found to arrest the cell cycle of A375 cells at the S phase, which was accompanied by a marked increase in the protein levels of cyclin E and a decrease in the protein levels of cyclin D1. In a cell culture system, AECS markedly induced the apoptosis of A375 cells, which was closely associated with the effects on the Bcl-2 family, whereby decreased Bcl-2 and increased Bak, Bax and Bad expression levels were observed. The underlying mechanism of AECS inhibiting A375 cell proliferation was associated with the induction of cell cycle arrest and apoptosis, indicating that AECS may present as a potential therapeutic agent for administration in human melanoma cancer intervention. PMID:24959287

  19. Hinokitiol Negatively Regulates Immune Responses through Cell Cycle Arrest in Concanavalin A-Activated Lymphocytes

    PubMed Central

    Chung, Chi-Li; Leung, Kam-Wing; Lu, Wan-Jung; Yen, Ting-Lin; He, Chia-Fu; Sheu, Joen-Rong; Lin, Kuan-Hung; Lien, Li-Ming

    2015-01-01

    Autoimmune diseases are a group of chronic inflammatory diseases that arise from inappropriate inflammatory responses. Hinokitiol, isolated from the wood of Chamaecyparis taiwanensis, engages in multiple biological activities. Although hinokitiol has been reported to inhibit inflammation, its immunological regulation in lymphocytes remains incomplete. Thus, we determined the effects of hinokitiol on concanavalin A- (ConA-) stimulated T lymphocytes from the spleens of mice. In the present study, the MTT assay revealed that hinokitiol (1–5 μM) alone did not affect cell viability of lymphocytes, but at the concentration of 5 μM it could reduce ConA-stimulated T lymphocyte proliferation. Moreover, propidium iodide (PI) staining revealed that hinokitiol arrested cell cycle of T lymphocytes at the G0/G1 phase. Hinokitiol also reduced interferon gamma (IFN-γ) secretion from ConA-activated T lymphocytes, as detected by an ELISA assay. In addition, hinokitiol also downregulated cyclin D3, E2F1, and Cdk4 expression and upregulated p21 expression. These results revealed that hinokitiol may regulate immune responses. In conclusion, we for the first time demonstrated that hinokitiol upregulates p21 expression and attenuates IFN-γ secretion in ConA-stimulated T lymphocytes, thereby arresting cell cycle at the G0/G1 phase. In addition, our findings also indicated that hinokitiol may provide benefits to treating patients with autoimmune diseases. PMID:26379747

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

    NASA Astrophysics Data System (ADS)

    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

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

    PubMed

    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 < 0.05) and decreased the percentage of cells in the S and G2/M phase. Honokiol down-regulated the expression of cyclin D1, cyclin D2, Cdk2, 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.

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

    PubMed

    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 < 0.05) and decreased the percentage of cells in the S and G2/M phase. Honokiol down-regulated the expression of cyclin D1, cyclin D2, Cdk2, 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

  3. Lipocortin 1 mediates dexamethasone-induced growth arrest of the A549 lung adenocarcinoma cell line.

    PubMed Central

    Croxtall, J D; Flower, R J

    1992-01-01

    The synthetic glucocorticoid dexamethasone (1 microM to 1 pM) strongly (maximum greater than 80%) inhibits proliferation of the A549 human lung adenocarcinoma line (EC50 greater than 1 nM) and leads to the appearance, or a further increase (approximately 3-fold) in the expression on the cell surface, of the calcium and phospholipid binding protein lipocortin (annexin) 1. Both these effects, which are shared by hydrocortisone (1 microM) but not by progesterone or aldosterone (1 microM), are inhibited by the antiglucocorticoids RU38486 and RU43044 (1 microM). The nonsteroidal antiinflammatory drugs indomethacin (1 microM) and naproxen (10 microM) and human recombinant lipocortin 1 (0.05-5.0 micrograms/ml) also produce growth arrest in this cell line. During proliferation A549 cells spontaneously release prostaglandin E2 [10-20 ng (28-57 pmol) per ml per 5-day period] into the growth medium. In concentrations that cause growth-arrest, dexamethasone, indomethacin, and lipocortin 1 abolish the generation of this eicosanoid by A549 cells. Prostaglandin E2 itself (0.01-1 pM) stimulates cell growth and partially reverses (approximately 50%) the inhibition of growth caused by dexamethasone and indomethacin. Addition of the neutralizing anti-lipocortin 1 monoclonal antibody 1A (5 micrograms/ml), but not the nonneutralizing anti-lipocortin monoclonal antibody 1B, substantially reversed (greater than 80%) the inhibitory activity of dexamethasone on both growth and prostaglandin E2 synthesis. The generation of prostaglandin E2 by A549 cells seems to be an important regulator of cell proliferation in vitro and the dexamethasone-induced suppression of proliferation in this model is attributable to eicosanoid inhibition caused by lipocortin 1. Images PMID:1533045

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

    PubMed Central

    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

  5. Crude Garlic Extract Inhibits Cell Proliferation and Induces Cell Cycle Arrest and Apoptosis of Cancer Cells In Vitro.

    PubMed

    Bagul, Mukta; Kakumanu, Srikanth; Wilson, Thomas A

    2015-07-01

    Garlic and its lipid-based extracts have played an important medicinal role in humans for centuries that includes antimicrobial, hypoglycemic, and lipid-lowering properties. The present study was to investigate the effects of crude garlic extract (CGE) on the proliferation of human breast, prostate, hepatic, and colon cancer cell lines and mouse macrophageal cells, not previously studied. The human cancer cell lines, such as hepatic (Hep-G2), colon (Caco-2), prostate (PC-3), and breast (MCF-7), were propagated at 37°C; air/CO2 (95:5 v/v) using the ATCC-formulated RPMI-1640 Medium and 10% fetal bovine serum (FBS), while the mouse macrophage cell line (TIB-71) was propagated at 37°C; air/CO2 (95:5 v/v) using the ATCC-formulated DMEM and 10% FBS. All cells were plated at a density of ∼5000 cells/well. After overnight incubation, the cells were treated with 0.125, 0.25, 0.5, or 1 μg/mL of CGE an additional 72 h. Inhibition of cell proliferation of 80-90% was observed for Hep-G2, MCF-7, TIB-71, and PC-3 cells, but only 40-55% for the Caco-2 cells when treated with 0.25, 0.5, or 1 μg/mL. In a coculture study of Caco-2 and TIB-71 cells, inhibition of cell proliferation of 90% was observed for Caco-2 cells compared to the 40-55% when cultured separately. CGE also induced cell cycle arrest and had a fourfold increase in caspase activity (apoptosis) in PC-3 cells when treated at a dose of 0.5 or 1 μg/mL. This investigation of CGE clearly highlights the fact that the lipid bioactive compounds in CGE have the potential as promising anticancer agents.

  6. Latexin sensitizes leukemogenic cells to gamma-irradiation-induced cell-cycle arrest and cell death through Rps3 pathway.

    PubMed

    You, Y; Wen, R; Pathak, R; Li, A; Li, W; St Clair, D; Hauer-Jensen, M; Zhou, D; Liang, Y

    2014-10-23

    Leukemia is a leading cause of cancer death. Recently, the latexin (Lxn) gene was identified as a potential tumor suppressor in several types of solid tumors and lymphoma, and Lxn expression was found to be absent or downregulated in leukemic cells. Whether Lxn functions as a tumor suppressor in leukemia and what molecular and cellular mechanisms are involved are unknown. In this study, the myeloid leukemogenic FDC-P1 cell line was used as a model system and Lxn was ectopically expressed in these cells. Using the protein pull-down assay and mass spectrometry, ribosomal protein subunit 3 (Rps3) was identified as a novel Lxn binding protein. Ectopic expression of Lxn inhibited FDC-P1 growth in vitro. More surprisingly, Lxn enhanced gamma irradiation-induced DNA damages and induced cell-cycle arrest and massive necrosis, leading to depletion of FDC-P1 cells. Mechanistically, Lxn inhibited the nuclear translocation of Rps3 upon radiation, resulting in abnormal mitotic spindle formation and chromosome instability. Rps3 knockdown increased the radiation sensitivity of FDC-P1, confirming that the mechanism of action of Lxn is mediated by Rps3 pathway. Moreover, Lxn enhanced the cytotoxicity of chemotherapeutic agent, VP-16, on FDC-P1 cells. Our study suggests that Lxn itself not only suppresses leukemic cell growth but also potentiates the cytotoxic effect of radio- and chemotherapy on cancer cells. Lxn could be a novel molecular target that improves the efficacy of anti-cancer therapy.

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

    PubMed

    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. Fisetin and hesperetin induced apoptosis and cell cycle arrest in chronic myeloid leukemia cells accompanied by modulation of cellular signaling.

    PubMed

    Adan, Aysun; Baran, Yusuf

    2016-05-01

    Fisetin and hesperetin, naturally occurring flavonoids, have been reported as novel antioxidants with chemopreventive/chemotherapeutic potential against various types of cancer. However, their mechanism of action in CML is still unknown. This particular study aims to evaluate the therapeutic potentials of fisetin and hesperetin and their effects on cell proliferation, apoptosis, and cell cycle progression in human K562 CML cells. The results indicated that fisetin and hesperetin inhibited cell proliferation and triggered programmed cell death in these cells. The latter was confırmed by mitochondrial membrane depolarization and an increase in caspase-3 activation. In addition to that, we have detected S and G2/M cell cycle arrests and G0/G1 arrest upon fisetin and hesperetin treatment, respectively. To identify the altered genes and genetic networks in response to fisetin and hesperetin, whole-genome microarray analysis was performed. The microarray gene profiling analysis revealed some important signaling pathways including JAK/STAT pathway, KIT receptor signaling, and growth hormone receptor signaling that were altered upon fisetin and hesperetin treatment. Moreover, microarray data suggested potential candidate genes for targeted CML therapy. Fisetin and hesperetin significantly modulated the expression of genes involved in cell proliferation and division, apoptosis, cell cycle regulation, and other significant cellular processes such as replication, transcription, and translation. In conclusion, our results suggest that fisetin and hesperetin as potential natural agents for CML therapy.

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

    SciTech Connect

    Fujii, Seiko; Okinaga, Toshinori; Ariyoshi, Wataru; Takahashi, Osamu; Iwanaga, Kenjiro; Nishino, Norikazu; Tominaga, Kazuhiro; Nishihara, Tatsuji

    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.

  10. Pea (Pisum sativum) cells arrested in G2 have nascent DNA with breaks between replicons and replication clusters

    SciTech Connect

    Van't Hof, J.

    1980-01-01

    DNA fiber autoradiography and alkaline sucrose sedimentation of DNA of cultured pea-root cells (Pisum sativum) arrested in G2 by carbohydrate starvation demonstrated that nascent DNA molecules of replicon (16 to 27 x 10/sup 6/D) and apparent cluster (approx. 330 x 10/sup 6/D) size were not joined. That the arrested cells were in G2 was confirmed by single-cell autoradiography and cytophotometry. In pea there are about 18 replicons per average cluster, 4.2 x 10/sup 3/ clusters, and 7.7 x 10/sup 4/ replicons per genome.

  11. Cytotoxic T lymphocytes block tumor growth both by lytic activity and IFNγ-dependent cell-cycle arrest.

    PubMed

    Matsushita, Hirokazu; Hosoi, Akihiro; Ueha, Satoshi; Abe, Jun; Fujieda, Nao; Tomura, Michio; Maekawa, Ryuji; Matsushima, Kouji; Ohara, Osamu; Kakimi, Kazuhiro

    2015-01-01

    To understand global effector mechanisms of CTL therapy, we performed microarray gene expression analysis in a murine model using pmel-1 T-cell receptor (TCR) transgenic T cells as effectors and B16 melanoma cells as targets. In addition to upregulation of genes related to antigen presentation and the MHC class I pathway, and cytotoxic effector molecules, cell-cycle-promoting genes were downregulated in the tumor on days 3 and 5 after CTL transfer. To investigate the impact of CTL therapy on the cell cycle of tumor cells in situ, we generated B16 cells expressing a fluorescent ubiquitination-based cell-cycle indicator (B16-fucci) and performed CTL therapy in mice bearing B16-fucci tumors. Three days after CTL transfer, we observed diffuse infiltration of CTLs into the tumor with a large number of tumor cells arrested at the G1 phase of the cell cycle, and the presence of spotty apoptotic or necrotic areas. Thus, tumor growth suppression was largely dependent on G1 cell-cycle arrest rather than killing by CTLs. Neutralizing antibody to IFNγ prevented both tumor growth inhibition and G1 arrest. The mechanism of G1 arrest involved the downregulation of S-phase kinase-associated protein 2 (Skp2) and the accumulation of its target cyclin-dependent kinase inhibitor p27 in the B16-fucci tumor cells. Because tumor-infiltrating CTLs are far fewer in number than the tumor cells, we propose that CTLs predominantly regulate tumor growth via IFNγ-mediated profound cytostatic effects rather than via cytotoxicity. This dominance of G1 arrest over other mechanisms may be widespread but not universal because IFNγ sensitivity varied among tumors.

  12. The nonstructural protein NP1 of human bocavirus 1 induces cell cycle arrest and apoptosis in Hela cells

    SciTech Connect

    Sun, Bin; Cai, Yingyue; Li, Yongshu; Li, Jingjing; Liu, Kaiyu; Li, Yi; Yang, Yongbo

    2013-05-25

    Human bocavirus type 1 (HBoV1) is a newly identified pathogen associated with human respiratory tract illnesses. Previous studies demonstrated that proteins of HBoV1 failed to cause cell death, which is considered as a possible common feature of bocaviruses. However, our work showed that the NP1 of HBoV1 induced apoptotic cell death in Hela cells in the absence of viral genome replication and expression of other viral proteins. Mitochondria apoptotic pathway was involved in the NP1-induced apoptosis that was confirmed by apoptotic characteristics including morphological changes, DNA fragmentation and caspase activation. We also demonstrated that the cell cycle of NP1-transfected Hela cells was transiently arrested at G2/M phase followed by rapid appearance of apoptosis and that the N terminal domain of NP1 was critical to its nuclear localization and function in apoptosis induction in Hela cells. These findings might provide alternative information for further study of mechanism of HBoV1 pathogenesis. - Highlights: ► NP1 protein of HBoV1 induced apoptosis in Hela cells was first reported. ► NP1 induced-apoptosis followed the cell cycle arrest at G2/M phase. ► The NP1 induced-apoptosis was mediated by mitochondrion apoptotic pathway. ► N terminal of NP1 was critical for apoptosis induction and nuclear localization.

  13. Ponicidin suppresses HT29 cell growth via the induction of G1 cell cycle arrest and apoptosis.

    PubMed

    Du, Jie; Chen, Chunyou; Sun, Yiqun; Zheng, Lin; Wang, Wanchen

    2015-10-01

    Ponicidin is a diterpenoid extracted from the Chinese herb Isodon adenolomus, which has been reported as a therapeutic cytotoxic drug that may be used to treat various types of human cancer. The present study aimed to determine the antitumor effects of ponicidin, and to investigate its underlying mechanisms in colorectal cancer. The HT29 colorectal cancer cell line was used to detect the cytotoxicity of various doses of ponicidin. Cell proliferation was measured using a Cell Counting kit‑8 assay. Cell cycle and apoptosis analyses were performed using flow cytometry and fluorescent microscopy. Western blot analysis was used to measure the expression levels of apoptosis‑associated proteins following treatment with ponicidin. Treatment with ponicidin significantly suppressed HT29 cell growth by inducing G1 cell cycle arrest and apoptosis. The AKT and MEK signaling pathways were also suppressed by ponicidin; however, the p38 signaling pathway was significantly activated. The expression levels of caspase 3 and Bax protein were markedly upregulated following treatment with ponicidin. These results suggest that ponicidin exerts significant antitumor effects via the induction of cell cycle arrest and apoptosis in colorectal cells. In conclusion, ponicidin acted as an inducer of apoptosis, and may be used as a therapeutic cytotoxic drug to treat human cancer, including colorectal cancer. PMID:26239027

  14. Ponicidin suppresses HT29 cell growth via the induction of G1 cell cycle arrest and apoptosis

    PubMed Central

    DU, JIE; CHEN, CHUNYOU; SUN, YIQUN; ZHENG, LIN; WANG, WANCHEN

    2015-01-01

    Ponicidin is a diterpenoid extracted from the Chinese herb Isodon adenolomus, which has been reported as a therapeutic cytotoxic drug that may be used to treat various types of human cancer. The present study aimed to determine the antitumor effects of ponicidin, and to investigate its underlying mechanisms in colorectal cancer. The HT29 colorectal cancer cell line was used to detect the cytotoxicity of various doses of ponicidin. Cell proliferation was measured using a Cell Counting kit-8 assay. Cell cycle and apoptosis analyses were performed using flow cytometry and fluorescent microscopy. Western blot analysis was used to measure the expression levels of apoptosis-associated proteins following treatment with ponicidin. Treatment with ponicidin significantly suppressed HT29 cell growth by inducing G1 cell cycle arrest and apoptosis. The AKT and MEK signaling pathways were also suppressed by ponicidin; however, the p38 signaling pathway was significantly activated. The expression levels of caspase 3 and Bax protein were markedly upregulated following treatment with ponicidin. These results suggest that ponicidin exerts significant antitumor effects via the induction of cell cycle arrest and apoptosis in colorectal cells. In conclusion, ponicidin acted as an inducer of apoptosis, and may be used as a therapeutic cytotoxic drug to treat human cancer, including colorectal cancer. PMID:26239027

  15. Lithium increases proliferation of hippocampal neural stem/progenitor cells and rescues irradiation-induced cell cycle arrest in vitro.

    PubMed

    Zanni, Giulia; Di Martino, Elena; Omelyanenko, Anna; Andäng, Michael; Delle, Ulla; Elmroth, Kecke; Blomgren, Klas

    2015-11-10

    Radiotherapy in children causes debilitating cognitive decline, partly linked to impaired neurogenesis. Irradiation targets primarily cancer cells but also endogenous neural stem/progenitor cells (NSPCs) leading to cell death or cell cycle arrest. Here we evaluated the effects of lithium on proliferation, cell cycle and DNA damage after irradiation of young NSPCs in vitro.NSPCs were treated with 1 or 3 mM LiCl and we investigated proliferation capacity (neurosphere volume and bromodeoxyuridine (BrdU) incorporation). Using flow cytometry, we analysed apoptosis (annexin V), cell cycle (propidium iodide) and DNA damage (γH2AX) after irradiation (3.5 Gy) of lithium-treated NSPCs.Lithium increased BrdU incorporation and, dose-dependently, the number of cells in replicative phase as well as neurosphere growth. Irradiation induced cell cycle arrest in G1 and G2/M phases. Treatment with 3 mM LiCl was sufficient to increase NSPCs in S phase, boost neurosphere growth and reduce DNA damage. Lithium did not affect the levels of apoptosis, suggesting that it does not rescue NSPCs committed to apoptosis due to accumulated DNA damage.Lithium is a very promising candidate for protection of the juvenile brain from radiotherapy and for its potential to thereby improve the quality of life for those children who survive their cancer.

  16. Podophyllotoxin acetate triggers anticancer effects against non-small cell lung cancer cells by promoting cell death via cell cycle arrest, ER stress and autophagy

    PubMed Central

    CHOI, JAE YEON; HONG, WAN GI; CHO, JEONG HYUN; KIM, EUN MI; KIM, JONGDOO; JUNG, CHAN-HUN; HWANG, SANG-GU; UM, HONG-DUCK; PARK, JONG KUK

    2015-01-01

    We previously reported that podophyllotoxin acetate (PA) radiosensitizes NCI-H460 cells. Here, we confirmed that PA treatment also induces cell death among two other non-small cell lung cancer (NSCLC) cell lines: NCI-H1299 and A549 cells (IC50 values = 7.6 and 16.1 nM, respectively). Our experiments further showed that PA treatment was able to induce cell death via various mechanisms. First, PA dose-dependently induced cell cycle arrest at G2/M phase, as shown by accumulation of the mitosis-related proteins, p21, survivin and Aurora B. This G2/M phase arrest was due to the PA-induced inhibition of microtubule polymerization. Together, the decreased microtubule polymerization and increased cell cycle arrest induced DNA damage (reflected by accumulation of γ-H2AX) and triggered the induction of intrinsic and extrinsic apoptotic pathways, as shown by the time-dependent activations of caspase-3, -8 and -9. Second, PA time-dependently activated the pro-apoptotic ER stress pathway, as evidenced by increased expression levels of BiP, CHOP, IRE1-α, phospho-PERK, and phospho-JNK. Third, PA activated autophagy, as reflected by time-dependent increases in the expression levels of beclin-1, Atg3, Atg5 and Atg7, and the cleavage of LC3. Collectively, these results suggest a model wherein PA decreases microtubule polymerization and increases cell cycle arrest, thereby inducing apoptotic cell death via the activation of DNA damage, ER stress and autophagy. PMID:26314270

  17. Induction of apoptosis and cell cycle arrest in human HCC MHCC97H cells with Chrysanthemum indicum extract

    PubMed Central

    Li, Zong-Fang; Wang, Zhi-Dong; Ji, Yuan-Yuan; Zhang, Shu; Huang, Chen; Li, Jun; Xia, Xian-Ming

    2009-01-01

    AIM: To investigate the effects of Chrysanthemum indicum extract (CIE) on inhibition of proliferation and on apoptosis, and the underlying mechanisms, in a human hepatocellular carcinoma (HCC) MHCC97H cell line. METHODS: Viable rat hepatocytes and human endothelial ECV304 cells were examined by trypan blue exclusion and MTT assay, respectively, as normal controls. The proliferation of MHCC97H cells was determined by MTT assay. The cellular morphology of MHCC97H cells was observed by phase contrast microscopy. Flow cytometry was performed to analyze cell apoptosis with annexin V/propidium iodide (PI), mitochondrial membrane potential with rhodamine 123 and cell cycle with PI in MHCC97H cells. Apoptotic proteins such as cytochrome C, caspase-9, caspase-3 and cell cycle proteins, including P21 and CDK4, were measured by Western blotting. RESULTS: CIE inhibited proliferation of MHCC97H cells in a time- and dose-dependent manner without cytotoxicity in rat hepatocytes and human endothelial cells. CIE induced apoptosis of MHCC97H cells in a concentration-dependent manner, as determined by flow cytometry. The apoptosis was accompanied by a decrease in mitochondrial membrane potential, release of cytochrome C and activation of caspase-9 and caspase-3. CIE arrested the cell cycle in the S phase by increasing P21 and decreasing CDK4 protein expression. CONCLUSION: CIE exerted a significant apoptotic effect through a mitochondrial pathway and arrested the cell cycle by regulation of cell cycle-related proteins in MHCC97H cells without an effect on normal cells. The cancer-specific selectivity shown in this study suggests that the plant extract could be a promising novel treatment for human cancer. PMID:19777612

  18. Modulation of docetaxel-induced apoptosis and cell cycle arrest by all- trans retinoic acid in prostate cancer cells

    PubMed Central

    Nehmé, A; Varadarajan, P; Sellakumar, G; Gerhold, M; Niedner, H; Zhang, Q; Lin, X; Christen, R D

    2001-01-01

    We report that all- trans retinoic acid (ATRA) enhanced the toxicity of docetaxel against DU145 and LNCaP prostate cancer cells, and that the nature of the interaction between ATRA and docetaxel was highly synergistic. Docetaxel-induced apoptotic cell death was associated with phosphorylation and hence inactivation of Bcl-2. ATRA enhanced docetaxel-induced apoptosis and combined treatment with ATRA and docetaxel resulted in down-regulation of Bcl-2. Docetaxel caused phosphorylation and hence inactivation of cdc2 kinase result ing in G2/M arrest. ATRA inhibited docetaxel-induced phosphorylation of cdc2 resulting in activation of cdc2 kinase and partial reversal of the G2/M arrest. ATRA also inhibited docetaxel-induced activation of MAPK indicating that the effects of docetaxel and ATRA on cdc2 phosphorylation are dependent on MAPK. We conclude that ATRA synergistically enhances docetaxel toxicity by down-regulating Bcl-2 expression and partially reverses the docetaxel-induced G2/M arrest by inhibiting docetaxel-induced cdc2 phosphorylation in a pathway that is dependent on MAPK. © 2001 Cancer Research Campaign http://www.bjcancer.com PMID:11384110

  19. The temperature arrested intermediate of virus-cell fusion is a functional step in HIV infection.

    PubMed

    Henderson, Hamani I; Hope, Thomas J

    2006-05-25

    HIV entry occurs via membrane-mediated fusion of virus and target cells. Interactions between gp120 and cellular co-receptors lead to both the formation of fusion pores and release of the HIV genome into target cells. Studies using cell-cell fusion assays have demonstrated that a temperature-arrested state (TAS) can generate a stable intermediate in fusion related events. Other studies with MLV pseudotyped with HIV envelope also found that a temperature sensitive intermediate could be generated as revealed by the loss of a fluorescently labeled membrane. However, such an intermediate has never been analyzed in the context of virus infection. Therefore, we used virus-cell infection with replication competent HIV to gain insights into virus-cell fusion. We find that the TAS is an intermediate in the process culminating in the HIV infection of a target cell. In the virion-cell TAS, CD4 has been engaged, the heptad repeats of gp41 are exposed and the complex is kinetically predisposed to interact with coreceptor to complete the fusion event leading to infection.

  20. High-frequency ultrasound analysis of post-mitotic arrest cell death

    PubMed Central

    Pasternak, Maurice M.; Wirtzfeld, Lauren A.; Kolios, Michael C.; Czarnota, Gregory J.

    2016-01-01

    Non-invasive monitoring of cancer cell death would permit rapid feedback on treatment response. One technique showing such promise is quantitative ultrasound. High-frequency ultrasound spectral radiofrequency analysis was used to study cell death in breast cancer cell samples. Quantitative ultrasound parameters, including attenuation, spectral slope, spectral 0-MHz-intercept, midband fit, and fitted parameters displayed significant changes with paclitaxel-induced cell death, corresponding to observations of morphological changes seen in histology and electron microscopy. In particular, a decrease in spectral slope from 0.24±0.07 dB/MHz to 0.04±0.09 dB/MHz occurred over 24 hours of treatment time and was identified as an ultrasound parameter capable of differentiating post-mitotic arrest cell death from classical apoptosis. The formation of condensed chromatin aggregates of 1 micron or greater in size increased the number of intracellular scatterers, consistent with a hypothesis that nuclear material is a primary source of ultrasound scattering in dying cells. It was demonstrated that the midband fit quantitatively correlated to cell death index, with a Pearson R-squared value of 0.99 at p<0.01. These results suggest that high-frequency ultrasound can not only qualitatively assess the degree of cancer cell death, but may be used to quantify the efficacy of chemotherapeutic treatments. PMID:27226984

  1. Cycle arrest and aneuploidy induced by zidovudine in murine embryonic stem cells.

    PubMed

    Campos, P B; Sartore, R C; Ramalho, B L; Costa, E S; Rehen, S K

    2012-07-01

    Zidovudine (3'-azido-3'-deoxythymidine; AZT) is a nucleoside analogue widely used for the treatment of acquired immune deficiency syndrome (AIDS). Medical guidelines recommend the use of AZT by pregnant women in order to reduce risk of HIV vertical transmission. Although it is efficacious, little is known about the side effects of AZT on embryonic development. In this sense, we used murine embryonic stem (mES) cells as a model to investigate the consequences of AZT exposure for embryogenesis. Firstly, mES colonies were incubated with AZT (50 or 100 μM) and cell cycle profile was evaluated. While 27.7 ± 5.43% of untreated mES cells were in G2/M phase, this percentage raised to 45.96 ± 4.18% after AZT exposure (100 μM). To identify whether accumulation of cells in G2/M phase could be related to chromosome missegregation with consequent cell cycle arrest, aneuploidy rate was evaluated after AZT treatment. Untreated colonies presented 39.6 ± 8.4% of cells aneuploid, while after AZT 100 μM treatment, the proportion of aneuploid cells raised to 67.8 ± 3.4% with prevalence of chromosome loss. This event was accompanied by micronuclei formation as AZT 100 μM treated mES cells presented a 2-fold increase compared to untreated ones. These data suggest that AZT exerts genotoxic effects and increases chromosome instability at early stages of embryonic development.

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

    PubMed

    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

  3. Piperlongumine induces gastric cancer cell apoptosis and G2/M cell cycle arrest both in vitro and in vivo.

    PubMed

    Duan, Chaoqin; Zhang, Bin; Deng, Chao; Cao, Yu; Zhou, Fan; Wu, Longyun; Chen, Min; Shen, Shanshan; Xu, Guifang; Zhang, Shu; Duan, Guihua; Yan, Hongli; Zou, Xiaoping

    2016-08-01

    Recently, several studies have shown that piperlongumine (PL) can selectively kill cancer cells by targeting reactive oxygen species (ROS). However, the potential therapeutic effects and detailed mechanism of PL in gastric cancer are still not clear. In the current report, we found that PL significantly suppressed gastric cancer both in vitro and in vivo. PL obviously increased ROS generation in gastric cancer cells. Anti-oxidant glutathione (GSH) and N-acetyl-L-cysteine (NAC) can abrogate PL-induced gastric cancer cell death and proliferation inhibition. GADD45α was induced in PL-treated cancer cells and led to G2/M phase arrest, whereas genetic depletion of GADD45α by small interfering RNAs (siRNAs) could partly reverse PL-induced cell cycle arrest in gastric cancer cells. Interestingly, we also found that PL treatment decreased the expression of telomerase reverse transcriptase (TERT) gene, which plays an essential role in cancer initiation and progression. Our findings thus revealed a potential anti-tumor effect of PL on gastric cancer cells and may have therapeutic implications.

  4. Hinokitiol Induces DNA Damage and Autophagy followed by Cell Cycle Arrest and Senescence in Gefitinib-Resistant Lung Adenocarcinoma Cells

    PubMed Central

    Li, Lan-Hui; Wu, Ping; Lee, Jen-Yi; Li, Pei-Rong; Hsieh, Wan-Yu; Ho, Chao-Chi; Ho, Chen-Lung; Chen, Wan-Jiun; Wang, Chien-Chun; Yen, Muh-Yong; Yang, Shun-Min; Chen, Huei-Wen

    2014-01-01

    Despite good initial responses, drug resistance and disease recurrence remain major issues for lung adenocarcinoma patients with epidermal growth factor receptor (EGFR) mutations taking EGFR-tyrosine kinase inhibitors (TKI). To discover new strategies to overcome this issue, we investigated 40 essential oils from plants indigenous to Taiwan as alternative treatments for a wide range of illnesses. Here, we found that hinokitiol, a natural monoterpenoid from the heartwood of Calocedrus formosana, exhibited potent anticancer effects. In this study, we demonstrated that hinokitiol inhibited the proliferation and colony formation ability of lung adenocarcinoma cells as well as the EGFR-TKI-resistant lines PC9-IR and H1975. Transcriptomic analysis and pathway prediction algorithms indicated that the main implicated pathways included DNA damage, autophagy, and cell cycle. Further investigations confirmed that in lung cancer cells, hinokitiol inhibited cell proliferation by inducing the p53-independent DNA damage response, autophagy (not apoptosis), S-phase cell cycle arrest, and senescence. Furthermore, hinokitiol inhibited the growth of xenograft tumors in association with DNA damage and autophagy but exhibited fewer effects on lung stromal fibroblasts. In summary, we demonstrated novel mechanisms by which hinokitiol, an essential oil extract, acted as a promising anticancer agent to overcome EGFR-TKI resistance in lung cancer cells via inducing DNA damage, autophagy, cell cycle arrest, and senescence in vitro and in vivo. PMID:25105411

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

    PubMed

    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

  6. A new antitumor arabinopyranoside from Laurencia majuscula induces G2/M cell cycle arrest.

    PubMed

    Du, Bin; Zhong, Xueyun; Liao, Xiaojian; Xu, Wenjie; Zhou, Xulong; Xu, Shihai

    2010-10-01

    A new arabinopyranoside was isolated from the alga Laurencia majuscula (Harvey) Lucas, collected from the Xisha Islands in the South China Sea. Its structure was elucidated as hexadecyl-1-O-α-L-arabinopyranoside by spectroscopic analysis. It was found that arabinopyranoside had significant antitumor activity in LOVO and Bel-7402 cell lines. Flow cytometric analysis showed that arabinopyranoside arrested the cell cycle in the G2/M phase. Western blotting demonstrated that the protein expression of CDK1 and cyclin A related to the G2/M phase decreased markedly with arabinopyranoside treatment, with slight changes in cyclin B1 expression. Taken together, the findings identify a potential new antitumor therapeutic arabinopyranoside isolated from red alga Laurencia majuscula.

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

    PubMed Central

    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

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

    PubMed Central

    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.

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

    PubMed

    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

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

    PubMed

    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.

  11. Effects of Adenovirus Type 5 E1A Isoforms on Viral Replication in Arrested Human Cells

    PubMed Central

    Radko, Sandi; Jung, Richard; Olanubi, Oladunni; Pelka, Peter

    2015-01-01

    Human adenovirus has evolved to infect and replicate in terminally differentiated human epithelial cells, predominantly those within the airway, the gut, or the eye. To overcome the block to viral DNA replication present in these cells, the virus expresses the Early 1A proteins (E1A). These immediate early proteins drive cells into S-phase and induce expression of all other viral early genes. During infection, several E1A isoforms are expressed with proteins of 289, 243, 217, 171, and 55 residues being present for human adenovirus type 5. Here we examine the contribution that the two largest E1A isoforms make to the viral life cycle in growth-arrested normal human fibroblasts. Viruses that express E1A289R were found to replicate better than those that do not express this isoform. Importantly, induction of several viral genes was delayed in a virus expressing E1A243R, with several viral structural proteins undetectable by western blot. We also highlight the changes in E1A isoforms detected during the course of viral infection. Furthermore, we show that viral DNA replication occurs more efficiently, leading to higher number of viral genomes in cells infected with viruses that express E1A289R. Finally, induction of S-phase specific genes differs between viruses expressing different E1A isoforms, with those having E1A289R leading to, generally, earlier activation of these genes. Overall, we provide an overview of adenovirus replication using modern molecular biology approaches and further insights into the contribution that E1A isoforms make to the life cycle of human adenovirus in arrested human fibroblasts. PMID:26448631

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

    PubMed Central

    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

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

    PubMed

    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

  14. Trypanosoma cruzi-induced immunosuppression: B cells undergo spontaneous apoptosis and lipopolysaccharide (LPS) arrests their proliferation during acute infection

    PubMed Central

    Zuñiga, E; Motran, C; Montes, C L; Diaz, F L; Bocco, J L; Gruppi, A

    2000-01-01

    Acute infection with Trypanosoma cruzi is characterized by multiple manifestations of immunosuppression of both cellular and humoral responses. B cells isolated at the acute stage of infection have shown marked impairment in their response to polyclonal activators in vitro. The present work aims at studying the B cell compartment in the context of acute T. cruzi infection to provide evidence for B cell activation, spontaneous apoptosis and arrest of the cell cycle upon mitogenic stimulation as a mechanism underlying B cell hyporesponse. We found that B cells from acutely infected mice, which fail to respond to the mitogen LPS, showed spontaneous proliferation and production of IgM, indicating a high level of B cell activation. Furthermore, these activated B cells also exhibited an increase in Fas expression and apoptosis in cultures without an exogenous stimulus. On the other hand, B cells from early acute and chronic infected mice did not present activation or apoptosis, and were able to respond properly to the mitogen. Upon in vitro stimulation with LPS, B cells from hyporesponder mice failed to progress through the cell cycle (G0/G1 arrest), nor did they increase the levels of apoptosis. These results indicate that B cell apoptosis and cell cycle arrest could be the mechanisms that control intense B cell expansion, but at the same time could be delaying the emergence of a specific immune response against the parasite. PMID:10691924

  15. Cardiac arrest

    MedlinePlus

    ... Article.jsp. Accessed June 16, 2014. Myerburg RJ, Castellanos A. Approach to cardiac arrest and life-threatening ... PA: Elsevier Saunders; 2011:chap 63. Myerburg RJ, Castellanos A. Cardiac arrest and audden aardiac death. In: ...

  16. Omacetaxine mepesuccinate induces apoptosis and cell cycle arrest, promotes cell differentiation, and reduces telomerase activity in diffuse large B-cell lymphoma cells

    PubMed Central

    ZHANG, LINA; CHEN, ZHENZHU; ZUO, WENLI; ZHU, XINGHU; LI, YUFU; LIU, XINJIAN; WEI, XUDONG

    2016-01-01

    Clinical studies have demonstrated that omacetaxine mepesuccinate exerts beneficial effects on acute myelogenous leukemia. It has been suggested that omacetaxine mepesuccinate, used alone or with interferon-α or cytarabine, induces remission in patients with chronic myelogenous leukemia. These effects are possibly mediated by its ability to induce apoptosis of leukemia cells and inhibit the activity of telomerase. To determine whether omacetaxine mepesuccinate is beneficial in diffuse large B-cell lymphoma (DLBCL), two DLBCL cell lines [a germinal center B cell-like subtype (GCB) and an activated B cell-like subtype (ABC)] were treated with omacetaxine mepesuccinate at various concentrations for different durations. The present study indicated that omacetaxine mepesuccinate exerts proapoptotic effects in the two cell types in a dose- and time-dependent manner. The ABC subtype demonstrated increased sensitivity compared with the GCB subtype. At 40 ng/ml, omacetaxine mepesuccinate exhibited a marked proapoptotic effect on DLBCL cells compared with the other tumor cells investigated. Furthermore, omacetaxine mepesuccinate induced cell cycle arrest at G0/G1 phase, and promoted cell terminal differentiation of pro-B cells. The present study also demonstrated that omacetaxine mepesuccinate exerted its antitumor effect by reducing telomerase activity. In conclusion, the present study demonstrated that omacetaxine mepesuccinate may induce apoptosis and cell cycle arrest, promote cell differentiation, and reduce telomerase activity in DLBCL cells, thus aiding the development of omacetaxine mepesuccinate-based DLBCL therapeutic strategies. PMID:26935769

  17. Neonatal bisphenol A exposure induces meiotic arrest and apoptosis of spermatogenic cells

    PubMed Central

    Xie, Meina; Bu, Pengli; Li, Fengjie; Lan, Shijian; Wu, Hongjuan; Yuan, Lu; Wang, Ying

    2016-01-01

    Bisphenol A (BPA) is a widely used industrial plasticizer, which is ubiquitously present in the environment and organisms. As an endocrine disruptor, BPA has caused significant concerns regarding its interference with reproductive function. However, little is known about the impact of BPA exposure on early testicular development. The aim of the present study was to investigate the influence of neonatal BPA exposure on the first wave of spermatogenesis. Newborn male mice were subcutaneously injected with BPA (0.01, 0.1 and 5 mg/kg body weight) daily from postnatal day (PND) 1 to 21. Histological analysis of testes at PND 22 revealed that BPA-treated testes contained mostly spermatogonia and spermatocytes with markedly less round spermatids, indicating signs of meiotic arrest. Terminal dUTP nick-end labeling (TUNEL) assay showed that BPA treatment significantly increased the number of apoptotic germ cells per tubule, which corroborated the observation of meiotic arrest. In addition, BPA caused abnormal proliferation of germ cells as revealed by Proliferating Cell Nuclear Antigen (PCNA) immunohistochemical staining. Mechanistically, BPA-treated testes displayed a complete lack of BOULE expression, which is a conserved key regulator for spermatogenesis. Moreover, BPA significantly increased the expression of estrogen receptor (ER) α and β in the developing testis. The present study demonstrated that neonatal BPA exposure disrupted meiosis progression during the first wave of spermatogenesis, which may be, at least in part, due to inhibition of BOULE expression and/or up-regulation of ERα/β expression in BPA-exposed developing testis. PMID:26863571

  18. Neonatal bisphenol A exposure induces meiotic arrest and apoptosis of spermatogenic cells.

    PubMed

    Xie, Meina; Bu, Pengli; Li, Fengjie; Lan, Shijian; Wu, Hongjuan; Yuan, Lu; Wang, Ying

    2016-03-01

    Bisphenol A (BPA) is a widely used industrial plasticizer, which is ubiquitously present in the environment and organisms. As an endocrine disruptor, BPA has caused significant concerns regarding its interference with reproductive function. However, little is known about the impact of BPA exposure on early testicular development. The aim of the present study was to investigate the influence of neonatal BPA exposure on the first wave of spermatogenesis. Newborn male mice were subcutaneously injected with BPA (0.01, 0.1 and 5 mg/kg body weight) daily from postnatal day (PND) 1 to 21. Histological analysis of testes at PND 22 revealed that BPA-treated testes contained mostly spermatogonia and spermatocytes with markedly less round spermatids, indicating signs of meiotic arrest. Terminal dUTP nick-end labeling (TUNEL) assay showed that BPA treatment significantly increased the number of apoptotic germ cells per tubule, which corroborated the observation of meiotic arrest. In addition, BPA caused abnormal proliferation of germ cells as revealed by Proliferating Cell Nuclear Antigen (PCNA) immunohistochemical staining. Mechanistically, BPA-treated testes displayed a complete lack of BOULE expression, which is a conserved key regulator for spermatogenesis. Moreover, BPA significantly increased the expression of estrogen receptor (ER) α and β in the developing testis. The present study demonstrated that neonatal BPA exposure disrupted meiosis progression during the first wave of spermatogenesis, which may be, at least in part, due to inhibition of BOULE expression and/or up-regulation of ERα/β expression in BPA-exposed developing testis. PMID:26863571

  19. Measles virus C protein suppresses gamma-activated factor formation and virus-induced cell growth arrest

    SciTech Connect

    Yokota, Shin-ichi; Okabayashi, Tamaki; Fujii, Nobuhiro

    2011-05-25

    Measles virus (MeV) produces two accessory proteins, V and C, from the P gene. These accessory proteins have been reported to contribute to efficient virus proliferation through the modulation of host cell events. Our previous paper described that Vero cell-adapted strains of MeV led host cells to growth arrest through the upregulation of interferon regulatory factor 1 (IRF-1), and wild strains did not. In the present study, we found that C protein expression levels varied among MeV strains in infected SiHa cells. C protein levels were inversely correlated with IRF-1 expression levels and with cell growth arrest. Forced expression of C protein released cells from growth arrest. C-deficient recombinant virus efficiently upregulated IRF-1 and caused growth arrest more efficiently than the wild-type virus. C protein preferentially bound to phosphorylated STAT1 and suppressed STAT1 dimer formation. We conclude that MeV C protein suppresses IFN-{gamma} signaling pathway via inhibition of phosphorylated STAT1 dimerization.

  20. CpG oligodeoxynucleotide induces apoptosis and cell cycle arrest in A20 lymphoma cells via TLR9-mediated pathways.

    PubMed

    Qi, Xu-Feng; Zheng, Li; Kim, Cheol-Su; Lee, Kyu-Jae; Kim, Dong-Heui; Cai, Dong-Qing; Qin, Jun-Wen; Yu, Yan-Hong; Wu, Zheng; Kim, Soo-Ki

    2013-07-01

    Recent studies have suggested that the anti-cancer activity of CpG-oligodeoxynucleotides (CpG-ODNs) is owing to their immunomodulatory effects in tumor-bearing host. The purpose of this study is to investigate the directly cytotoxic activity of KSK-CpG, a novel CpG-ODN with an alternative CpG motif, against A20 and EL4 lymphoma cells in comparison with previously used murine CpG motif (1826-CpG). To evaluate the potential cytotoxic effects of KSK-CpG on lymphoma cells, cell viability assay, confocal microscopy, flow cytometry, DNA fragmentation, Western blotting, and reverse transcription-polymerase chain reaction (RT-PCR) analysis were used. We found that KSK-CpG induced direct cytotoxicity in A20 lymphoma cells, but not in EL4 lymphoma cells, at least in part via TLR9-mediated pathways. Apoptotic cell death was demonstrated to play an important role in CpG-ODNs-induced cytotoxicity. In addition, both mitochondrial membrane potential decrease and G1-phase arrest were involved in KSK-CpG-induced apoptosis in A20 cells. The activities of apoptotic molecules such as caspase-3, PARP, and Bax were increased, but the activation of p27 Kip1 and ERK were decreased in KSK-CpG-treated A20 cells. Furthermore, autocrine IFN-γ partially contributed to apoptotic cell death in KSK-CpG-treated A20 cells. Collectively, our findings suggest that KSK-CpG induces apoptotic cell death in A20 lymphoma cells at least in part by inducing G1-phase arrest and autocrine IFN-γ via increasing TLR9 expression, without the need for immune system of tumor-bearing host. This new understanding supports the development of TLR9-targeted therapy with CpG-ODN as a direct therapeutic agent for treating B lymphoma. PMID:23357786

  1. Imaging bone morphogenetic protein 7 induced cell cycle arrest in experimental gliomas.

    PubMed

    Klose, Anke; Waerzeggers, Yannic; Monfared, Parisa; Vukicevic, Slobodan; Kaijzel, Eric L; Winkeler, Alexandra; Wickenhauser, Claudia; Löwik, Clemens W G M; Jacobs, Andreas H

    2011-03-01

    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 G(1) 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.

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

    SciTech Connect

    Wu, William Ka Kei Wu Yachun; Yu Le; Li Zhijie; Sung, Joseph Jao Yiu; Cho, C.H.

    2008-09-19

    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 G{sub 2}/M cell cycle arrest which was associated with the formation of LC3{sup +} 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{sup +} 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.

  3. Appressorium formation in the corn smut fungus Ustilago maydis requires a G2 cell cycle arrest.

    PubMed

    Castanheira, Sónia; Pérez-Martín, José

    2015-01-01

    Many of the most important plant diseases are caused by fungal pathogens that form specialized cell structures to breach the leaf surface as well as to proliferate inside the plant. To initiate pathogenic development, the fungus responds to a set of inductive cues. Some of them are of extracellular nature (environmental signals) while others respond to intracellular conditions (developmental signals). These signals have to be integrated into a single response that has as a major outcome changes in the morphogenesis of the fungus. The cell cycle regulation is pivotal during these cellular differentiations, and we hypothesized that cell cycle regulation would be likely to provide control points for infection development by fungal pathogens. Although efforts have been done in various fungal systems, there is still limited information available regarding the relationship of these processes with the induction of the virulence programs. Hence, the role of fungal cell cycle regulators -which are wide conserved elements- as true virulence factors, has yet to be defined. Here we discuss the recent finding that the formation of the appressorium, a structure required for plant penetration, in the corn smut fungus Ustilago maydis seems to be incompatible with an active cell cycle and, therefore genetic circuits evolved in this fungus to arrest the cell cycle during the growth of this fungus on plant surface, before the appressorium-mediated penetration into the plant tissue.

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

    SciTech Connect

    McNeely, Samuel C.; Belshoff, Alex C.; Taylor, B. Frazier; Fan, Teresa W-M.; McCabe, Michael J.; Pinhas, Allan R.

    2008-06-01

    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-{pi} 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 G{sub 2}-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.

  5. Mechanisms involved in resveratrol-induced apoptosis and cell cycle arrest in prostate cancer-derived cell lines.

    PubMed

    Benitez, Dixan A; Pozo-Guisado, Eulalia; Alvarez-Barrientos, Alberto; Fernandez-Salguero, Pedro M; Castellón, Enrique A

    2007-01-01

    Resveratrol is a polyphenol found at high concentrations in grapes and red wine with reported anticarcinogenic effects. We studied the molecular mechanism of resveratrol-induced apoptosis and proliferation arrest in prostate derived cells PZ-HPV-7 (nontumorigenic line), LNCaP (androgen-sensitive cancer line), and PC-3 (androgen-insensitive cancer line). Apoptosis and cell cycle distribution were evaluated by flow cytometry and proliferation by MTT assay and direct cell counting. Caspases, bax, bcl-2, cyclins, Cdks, p53, p21, and p27 were measured by Western blot and kinase activities of cyclin/Cdk complexes by immunoprecipitation followed by kinase assays with appropriate substrates. Resveratrol induced a decrease in proliferation rates and an increase in apoptosis in cancer cell lines in a dose- and time-dependent manner. These effects were coincident with cell accumulation at the G0/G1 phase. In LNCaP and PC-3, the apoptosis induced by resveratrol was mediated by activation of caspases 9 and 3 and a change in the ratio of bax/bcl-2. Expressions of cyclin D1, E, and Cdk4 as well as cyclin D1/Cdk4 kinase activity were reduced by resveratrol only in LNCaP cells. In contrast, cyclin B and Cdk1 expression and cyclin B/Cdk1 kinase activity were decreased in both cell lines in the presence of resveratrol. However, modulator proteins p53, p21, and p27 were increased by resveratrol only in LNCaP cells. These effects probably result in the observed proliferation arrest and disruption of cell cycle control. In addition, the specific differences found between LNCaP and PC-3 suggest that resveratrol acts through different mechanisms upon the androgen or estrogen receptor cell status. PMID:17050787

  6. Mechanisms involved in resveratrol-induced apoptosis and cell cycle arrest in prostate cancer-derived cell lines.

    PubMed

    Benitez, Dixan A; Pozo-Guisado, Eulalia; Alvarez-Barrientos, Alberto; Fernandez-Salguero, Pedro M; Castellón, Enrique A

    2007-01-01

    Resveratrol is a polyphenol found at high concentrations in grapes and red wine with reported anticarcinogenic effects. We studied the molecular mechanism of resveratrol-induced apoptosis and proliferation arrest in prostate derived cells PZ-HPV-7 (nontumorigenic line), LNCaP (androgen-sensitive cancer line), and PC-3 (androgen-insensitive cancer line). Apoptosis and cell cycle distribution were evaluated by flow cytometry and proliferation by MTT assay and direct cell counting. Caspases, bax, bcl-2, cyclins, Cdks, p53, p21, and p27 were measured by Western blot and kinase activities of cyclin/Cdk complexes by immunoprecipitation followed by kinase assays with appropriate substrates. Resveratrol induced a decrease in proliferation rates and an increase in apoptosis in cancer cell lines in a dose- and time-dependent manner. These effects were coincident with cell accumulation at the G0/G1 phase. In LNCaP and PC-3, the apoptosis induced by resveratrol was mediated by activation of caspases 9 and 3 and a change in the ratio of bax/bcl-2. Expressions of cyclin D1, E, and Cdk4 as well as cyclin D1/Cdk4 kinase activity were reduced by resveratrol only in LNCaP cells. In contrast, cyclin B and Cdk1 expression and cyclin B/Cdk1 kinase activity were decreased in both cell lines in the presence of resveratrol. However, modulator proteins p53, p21, and p27 were increased by resveratrol only in LNCaP cells. These effects probably result in the observed proliferation arrest and disruption of cell cycle control. In addition, the specific differences found between LNCaP and PC-3 suggest that resveratrol acts through different mechanisms upon the androgen or estrogen receptor cell status.

  7. Capsaicin mediates cell cycle arrest and apoptosis in human colon cancer cells via stabilizing and activating p53.

    PubMed

    Jin, Junzhe; Lin, Guofu; Huang, Hong; Xu, Dong; Yu, Hao; Ma, Xu; Zhu, Lisi; Ma, Dongyan; Jiang, Honglei

    2014-01-01

    Capsaicin is the major pungent ingredient in red peppers which is world widely consumed. Except its potent pain relieving efficacy as reported, capsaicin also exerted its antitumor activity in several tumor models. Here, we reported that capsaicin had a profound anti-proliferative effect on human colon cancer cells via inducing cell cycle G0/G1 phase arrest and apoptosis, which was associated with an increase of p21, Bax and cleaved PARP. The underlying mechanism of capsaicin's antitumor potency was mainly attributed to the stabilization and activation of p53. Capsaicin substantially prolonged the half-life of p53 and significantly elevated the transcriptional activity of p53. Through suppressing the interaction between p53 and MDM2, MDM2-mediated p53 ubiquitination was remarkably decreased after capsaicin treatment, which resulted in the stabilization and accumulation of p53. The results of p53-shRNA experiment further demonstrated that p53 knockdown severely impaired the sensitivity of tested cells to capsaicin, G0/G1 phase arrest and the apoptosis induced by capsaicin in p53-knockdown cells was also dramatically decreased, implicating the important role of p53 played in capsaicin's antitumor activity. In summary, our data suggested that capsaicin, or a related analogue, may have a role in the management of human colon cancer.

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

    PubMed Central

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

    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 that S109 signifi cantly inhibits proliferation and colony formation of renal cancer cells. Cell cycle assay showed that S109 induced G1-phase arrest, followed by the reduction of Cyclin D1 and increased expression of p53 and p21. We also found that S109 induces nuclear accumulation of tumor suppressor proteins, Foxo1 and p27. Most importantly, mutation of CRM1 at Cys528 position abolished the eff ects of S109. Taken together, our results indicate that CRM1 is a therapeutic target in renal cancer and the novel reversible CRM1 inhibitor S109 can act as a promising candidate for renal cancer therapy. PMID:26937212

  9. Momordica cochinchinensis Spreng. seed extract suppresses breast cancer growth by inducing cell cycle arrest and apoptosis.

    PubMed

    Zheng, Lei; Zhang, Yanmin; Liu, Yanping; Yang, Xiaoyan Ou; Zhan, Yingzhuan

    2015-10-01

    The herb Momordica cochinchinensis has been used for a variety of purposes, and been shown to have anti‑cancer properties. The present study assessed the potency and the underlying mechanisms of action of the ethyl acetate extract of seeds of Momordica cochinchinensis (ESMC2) on breast cancer cells. Therefore, the effects of ESMC2 on the cell viability, cell cycle and apoptosis of MDA‑MB‑231 cells were investigated. The results showed that ESMC2 exerted a marked growth inhibitory effect on the cells. Cell cycle arrest in G2 phase following treatment with ESMC2 was associated with a marked increase in the protein levels of cyclin B1, cyclin E and cyclin-dependent kinase 1 and a decrease in cyclin D1 expression. In addition, ESMC2 dose‑dependently induced cell apoptosis, which was mediated via upregulation of the apoptosis-associated proteins p53, B-cell lymphoma 2 (Bcl‑2)‑associated X protein, Bcl-2 homologous antagonist killer and Bcl-2-associated death promoter expression, as well as downregulation of nuclear factor kappa B, Bcl‑2 and myeloid cell leukemia‑1. Furthermore, the activation of extracellular signal-regulated kinase 1/2, p38, c-Jun N-terminal kinase (JNK) and Akt phosphorylation were decreased by ESMC2 in a dose‑dependent manner, indicating that ESMC2 exerted its effects via the mitogen-activated protein kinase/JNK pathway. Furthermore, nude mouse xenotransplant models were used to evaluate the tumor growth inhibitory effects of ESMC2. The possible chemical components of ESMC2 were analyzed by gas chromatography-mass spectrometry, and 12 compounds were detected from the major peaks based on the similarity index with entries of a compound database. The results of the present study may aid in the development of novel therapies for breast cancer. PMID:26252798

  10. Induction of chromosome aberrations and mitotic arrest by cytomegalovirus in human cells

    SciTech Connect

    AbuBakar, S.; Au, W.W.; Legator, M.S.; Albrecht, T.

    1988-01-01

    Human cytomegalovirus (CMV) is potentially an effective but often overlooked genotoxic agent in humans. We report here evidence that indicates that infection by CMV can induce chromosome alterations and mitotic inhibition. The frequency of chromosome aberrations induced was dependent on the input multiplicity of infection (m.o.i.) for human lung fibroblasts (LU), but not for human peripheral blood lymphocytes (PBLs) when both cell types were infected at the GO phase of the cell cycle. The aberrations induced by CMV were mostly chromatid breaks and chromosome pulverizations that resembled prematurely condensed S-phase chromatin. Pulverized chromosomes were not observed in LU cells infected with virus stocks that had been rendered nonlytic by UV-irradiation at 24,000 ergs/mm2 or from infection of human lymphocytes. In LU cells infected with UV-irradiated CMV, the frequency of aberrations induced was inversely dependent on the extent of the exposure of the CMV stock to the UV-light. In permissive CMV infection of proliferating LU cells at 24 hr after subculture, a high percentage (greater than 40%) of the metaphase cells were arrested at their first metaphase and displayed severely condensed chromosomes when harvested 48 hr later. A significant increase (p less than 0.05) in the chromosome aberration frequency was also observed. Our study shows that CMV infection is genotoxic to host cells. The types and extent of damage are dependent on the viral genome expression and on the cell cycle stage of the cells at the time of infection. The possible mechanisms for induction of chromosome damage by CMV are discussed.

  11. Momordica cochinchinensis Spreng. seed extract suppresses breast cancer growth by inducing cell cycle arrest and apoptosis.

    PubMed

    Zheng, Lei; Zhang, Yanmin; Liu, Yanping; Yang, Xiaoyan Ou; Zhan, Yingzhuan

    2015-10-01

    The herb Momordica cochinchinensis has been used for a variety of purposes, and been shown to have anti‑cancer properties. The present study assessed the potency and the underlying mechanisms of action of the ethyl acetate extract of seeds of Momordica cochinchinensis (ESMC2) on breast cancer cells. Therefore, the effects of ESMC2 on the cell viability, cell cycle and apoptosis of MDA‑MB‑231 cells were investigated. The results showed that ESMC2 exerted a marked growth inhibitory effect on the cells. Cell cycle arrest in G2 phase following treatment with ESMC2 was associated with a marked increase in the protein levels of cyclin B1, cyclin E and cyclin-dependent kinase 1 and a decrease in cyclin D1 expression. In addition, ESMC2 dose‑dependently induced cell apoptosis, which was mediated via upregulation of the apoptosis-associated proteins p53, B-cell lymphoma 2 (Bcl‑2)‑associated X protein, Bcl-2 homologous antagonist killer and Bcl-2-associated death promoter expression, as well as downregulation of nuclear factor kappa B, Bcl‑2 and myeloid cell leukemia‑1. Furthermore, the activation of extracellular signal-regulated kinase 1/2, p38, c-Jun N-terminal kinase (JNK) and Akt phosphorylation were decreased by ESMC2 in a dose‑dependent manner, indicating that ESMC2 exerted its effects via the mitogen-activated protein kinase/JNK pathway. Furthermore, nude mouse xenotransplant models were used to evaluate the tumor growth inhibitory effects of ESMC2. The possible chemical components of ESMC2 were analyzed by gas chromatography-mass spectrometry, and 12 compounds were detected from the major peaks based on the similarity index with entries of a compound database. The results of the present study may aid in the development of novel therapies for breast cancer.

  12. Downregulation of coding transmembrane protein 35 gene inhibits cell proliferation, migration and cell cycle arrest in osteosarcoma cells

    PubMed Central

    Huang, Yinjun; Zhao, Shichang; Zhang, Yadong; Zhang, Changqing; Li, Xiaolin

    2016-01-01

    Osteosarcoma (OSA) is the most common primary tumor of the bone. Resistance to chemotherapy and the fast rapid development of metastatic lesions are major issues responsible for treatment failure and poor survival rates in OSA patients. Tetraspanins comprise a family of transmembrane receptor glycoproteins that affect tumor cell migration through tetraspanin-integrin interaction. The present study focused on a four-pass transmembrane protein gene, transmembrane protein 35 (TMEM35) gene, and examined its role in the growth, migration and cell cycle progression of OSA cells. In addition, the study discussed whether the TMEM35 gene, which encodes the TMEM35 protein, may be a potential therapeutic target for OSA. In the current study, reverse transcription-quantitative polymerase chain reaction was performed to examine TMEM35 expression in OSA and matched healthy tissues. Small interfering RNAs (siRNAs) were transfected into SaOS2 and U2OS cells to knockdown the TMEM35 expression. Soft-agar colony formation assay was performed to evaluate cell growth, and cell cycle progression was analyzed by flow cytometry. Wound-healing and Boyden chamber assays were also performed to investigate cell invasion and migration by the SaOS2 and U2OS cells. TMEM35 protein was analyzed in a functional protein interaction networks database (STRING database) to predict the functional interaction partner proteins of TMEM35. The results indicated that TMEM35 was abnormally expressed in OSA tissues. Of the 37 examined patients, TMEM35 expression was significantly increased in the OSA tissues of 24 patients (64.86%; P<0.05), when compared with the expression in normal tissues. Furthermore, TMEM35 knockdown following transfection with siRNAs inhibited the colony formation ability of SaOS2 and U2OS cells in soft agar. Flow cytometric analysis also revealed that TMEM35 knockdown by RNA interference may result in G1 phase arrest and a decreased cell population at the S phase. TMEM35 knockdown

  13. Unusual prolongation of radiation-induced G2 arrest in tumor xenografts derived from HeLa cells.

    PubMed

    Kaida, Atsushi; Miura, Masahiko

    2015-10-01

    The effect of ionizing radiation on cell cycle kinetics in solid tumors remains largely unknown because of technical limitations and these tumors' complicated structures. In this study, we analyzed intratumoral cell cycle kinetics after X-irradiation of tumor xenografts derived from HeLa cells expressing the fluorescent ubiquitination-based cell cycle indicator (Fucci), a novel system to visualize cell cycle kinetics in vivo. Cell cycle kinetics after X-irradiation was examined by using tumor sections and in vivo real-time imaging system in tumor xenografts derived from HeLa cells expressing Fucci. We found that G2 arrest was remarkably prolonged, up to 5 days after 10-Gy irradiation, in contrast to monolayer cultures where G2 arrest returned within 24 h. Cells isolated from tumors 5 days after irradiation exhibited a higher surviving fraction than those isolated immediately or one day after irradiation. In this study, we clearly demonstrated unusual post-irradiation cell cycle kinetics in tumor xenografts derived from HeLa-Fucci cells. Our findings imply that prolonged G2 arrest occurring in tumor microenvironments following irradiation may function as a radioresistance mechanism.

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

    PubMed

    So, Wai Wing; Liu, Wai Nam; Leung, Kwok Nam

    2015-08-18

    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.

  15. Changes in junctional communication associated with cell cycle arrest and differentiation of trochoblasts in embryos of Patella vulgata.

    PubMed

    Serras, F; Dictus, W J; Van den Biggelaar, J A

    1990-01-01

    In early embryos of molluscs, different clones of successively determined trochoblasts differentiate into prototroch cells and together contribute to the formation of a ciliated ring of cells known as the prototroch. Trochoblasts differentiate after cell cycle arrest, which occurs two cell cycles after the commitment of their stem cell. To study the changes of junctional communication in embryos of Patella vulgata in relation to commitment, cell cycle arrest, and differentiation of the trochoblasts, we have monitored electrical coupling as well as transfer of fluorescent dyes. The appearance of dye coupling in embryos of Patella occurs after the fifth cleavage (at the 32-cell stage), when the cell cycles of all embryonic cells become asynchronous and longer. At the 32- and 64-cell stages all cells are well coupled. However, after the 72-cell stage dye transfer to or from any cell of the four interradial clones of four primary trochoblasts becomes abruptly reduced, whereas electrical coupling between these cells and the rest of the embryo can still be detected. From scanning electron microscopical analysis of the cell pattern we conclude that this change in gap junctional communication coincides with cell cycle arrest and with the development of cilia in all four clones of primary trochoblasts. Similarly, after the 88-cell stage the four radial clones of accessory trochoblasts stop dividing, reduce cell coupling, and become ciliated. By the formation of the prototroch, the embryo becomes subdivided into an anterior (pretrochal) and a posterior (posttrochal) domain which will develop different structures of the adult. At the 88-cell stage, the cells within each of these two domains remain well coupled and form two different communication compartments that are separated from each other by the interposed ring of uncoupled trochoblasts. The relations among control of cell cycle, changes in junctional communication, and differentiation are discussed. PMID:2295366

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

    PubMed

    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

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

    NASA Astrophysics Data System (ADS)

    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

  18. ATR CONTRIBUTES TO CELL CYCLE ARREST AND SURVIVAL AFTER CISPLATIN BUT NOT OXALIPLATIN1

    PubMed Central

    Lewis, Kriste A.; Lilly, Kia K.; Reynolds, Evelyn A.; Sullivan, William P.; Kaufmann, Scott H.; Cliby, William A.

    2009-01-01

    The DNA cross-linking agents cisplatin and oxaliplatin are widely used in the treatment of human cancer. Lesions produced by these agents are widely known to activate the G1 and G2 cell cycle checkpoints. Less is known about the role of the intra-S phase checkpoint in the response to these agents. In the present study, two different cell lines expressing a dominant negative kinase-dead (kd) version of the ATR (ataxia telangiectasia and rad3-related) kinase in an inducible fashion were examined for their responses to these two platinating agents and a variety of other DNA cross-linking drugs. Expression of the kdATR allele markedly sensitized the cells to cisplatin, but not oxaliplatin, as assessed by inhibition of colony formation, induction of apoptosis, and cell cycle analysis. Similar differences in survival were noted for melphalan (ATR-dependent) and 4-hydroperoxycyclophosphamide (4HC) (ATR-independent). Further experiments demonstrated that ATR function is not necessary for removal of Pt-DNA adducts. The predominant difference between the responses to the two platinum drugs was presence of a drug-specific ATR-dependent S phase arrest after cisplatin but not oxaliplatin. These results indicate that involvement of ATR in the response to DNA cross-linking agents is lesion specific. This observation might need to be taken into account in the development and use of ATR or Chk1 inhibitors. PMID:19372558

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

    PubMed Central

    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

  20. Downregulation of L1CAM inhibits proliferation, invasion and arrests cell cycle progression in pancreatic cancer cells in vitro.

    PubMed

    Ben, Qiwen; An, Wei; Fei, Jian; Xu, Maojin; Li, Guixiang; Li, Zhaoshen; Yuan, Yaozong

    2014-04-01

    The aim of the present study was to establish the effect of silencing L1 cell adhesion molecule (L1CAM) on the proliferation, invasion, cell cycle progression and apoptosis of pancreatic cancer cells, and to determine the potential molecular mechanisms that are involved. The human Capan-2 pancreatic cancer cell line was infected with lentivirus-mediated short hairpin RNA (shRNA) to target L1CAM. Cell proliferation and invasion were analyzed using cell counting kit-8 and Transwell assays, respectively, and cell cycle progression and apoptosis were analyzed using flow cytometry. L1CAM protein expression in Capan-2 cells decreased following shRNA-L1CAM infection. Furthermore, knockdown of L1CAM significantly inhibited cell proliferation and reduced the number of invasive cells, while increasing the percentage of cells in the G0/G1 phase (P<0.05). However, the effect on apoptosis was not identified to be statistically significant. In addition, L1CAM silencing may induce activation of p38/extracellular signal regulated kinase 1/2. Downregulation of L1CAM may inhibit proliferation, invasion and arrests cell cycle progression in pancreatic cancer via p38/ERK1/2 signal pathway, and therefore, L1CAM may serve as a potential target for gene therapy in pancreatic cancer. PMID:24660028

  1. Effects of furanodiene on 95-D lung cancer cells: apoptosis, autophagy and G1 phase cell cycle arrest.

    PubMed

    Xu, Wen-Shan; Li, Ting; Wu, Guo-Sheng; Dang, Yuan-Ye; Hao, Wen-Hui; Chen, Xiu-Ping; Lu, Jin-Jian; Wang, Yi-Tao

    2014-01-01

    Furanodiene (FUR) is a natural terpenoid isolated from Rhizoma curcumae, a well-known Chinese medicinal herb that presents anti-proliferative activities in several cancer cell lines. Herein, we systematically investigated the effects of FUR on the significant processes of tumor progression with the relatively low concentrations in 95-D lung cancer cells. FUR concentration-dependently inhibited cell proliferation and blocked the cell cycle progressions in G1 phase by down-regulating the protein levels of cyclin D1 and CDK6, and up-regulating those of p21 and p27 in 95-D cells. FUR also affected the signaling molecules that regulate apoptosis in 95-D cells revealed by the down-regulation of the protein levels of full PARP, pro-caspase-7, survivin, and Bcl-2, and the up-regulation of cleaved PARP. Further studies showed that FUR enhanced the expression of light chain 3-II (LC3-II) in the protein level, indicating that autophagy is involved in this process. Besides, the adhesion ability of 95-D cells to matrigel and fibronectin was slightly inhibited after FUR treatment for 1 h in our experimental condition. FUR also slightly suppressed cell migration and invasion in 95-D cells according to the data from wound healing and Transwell assays, respectively. Taken together, FUR activated the signal molecules regulating G1 cell cycle arrest, apoptosis and autophagy, while slightly affecting the key steps of cell metastasis in 95-D lung cancer cells in the relatively low concentrations.

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

    SciTech Connect

    Li, Lin; Yue, Grace G.L.; Lau, Clara B.S.; Sun, Handong; Fung, Kwok Pui; Leung, Ping Chung; Han, Quanbin; Leung, Po Sing

    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.

  3. Ziyuglycoside II induces cell cycle arrest and apoptosis through activation of ROS/JNK pathway in human breast cancer cells.

    PubMed

    Zhu, Xue; Wang, Ke; Zhang, Kai; Zhu, Ling; Zhou, Fanfan

    2014-05-16

    Ziyuglycoside II, a triterpenoid saponin compound extracted from Sanguisorba officinalis L., has been reported to have a wide range of clinical applications including anti-cancer effect. In this study, the anti-proliferative effect of ziyuglycoside II in two classic human breast cancer cell lines, MCF-7 and MDA-MB-231, was extensively investigated. Our study indicated that ziyuglycoside II could effectively induce G2/M phase arrest and apoptosis in both cell lines. Cell cycle blocking was associated with the down-regulation of Cdc25C, Cdc2, cyclin A and cyclin B1 as well as the up-regulation of p21/WAF1, phospho-Cdc25C and phospho-Cdc2. Ziyuglycoside II treatment also induced reactive oxygen species (ROS) production and apoptosis by activating the extrinsic/Fas/FasL pathway as well as the intrinsic/mitochondrial pathway. More importantly, the c-Jun NH2-terminal kinase (JNK), a downstream target of ROS, was found to be a critical mediator of ziyuglycoside II-induced cell apoptosis. Further knockdown of JNK by siRNA could inhibit ziyuglycoside II-mediated apoptosis with attenuating the up-regulation of Bax and Fas/FasL as well as the down-regulation of Bcl-2. Taken together, the cell death of breast cancer cells in response to ziyuglycoside II was dependent upon cell cycle arrest and cell apoptosis via a ROS-dependent JNK activation pathway. Our findings may significantly contribute to the understanding of the anti-proliferative effect of ziyuglycoside II, in particular to breast carcinoma and provide novel insights into the potential application of such compound in breast cancer therapy. PMID:24680927

  4. AM251 induces apoptosis and G2/M cell cycle arrest in A375 human melanoma cells.

    PubMed

    Carpi, Sara; Fogli, Stefano; Romanini, Antonella; Pellegrino, Mario; Adinolfi, Barbara; Podestà, Adriano; Costa, Barbara; Da Pozzo, Eleonora; Martini, Claudia; Breschi, Maria Cristina; Nieri, Paola

    2015-08-01

    Human cutaneous melanoma is an aggressive and chemotherapy-resistant type of cancer. AM251 is a cannabinoid type 1 (CB1) receptor antagonist/inverse agonist with off-target antitumor activity against pancreatic and colon cancer cells. The current study aimed to characterize the in-vitro antimelanoma activity of AM251. The BRAF V600E mutant melanoma cell line, A375, was used as an in-vitro model system. Characterization tools included a cell viability assay, nuclear morphology assessment, gene expression, western blot, flow cytometry with Annexin V-FITC/7-AAD double staining, cell cycle analyses, and measurements of changes in intracellular cAMP and calcium concentrations. AM251 exerted a marked cytotoxic effect against A375 human melanoma cells with potency comparable with that observed for cisplatin without significant changes in the human dermal fibroblasts viability. AM251, at a concentration that approximates the IC50, downregulated genes encoding antiapoptotic proteins (BCL2 and survivin) and increased transcription levels of proapoptotic BAX, induced alteration of Annexin V reactivity, DNA fragmentation, chromatin condensation in the cell nuclei, and G2/M phase arrest.AM251 also induced a 40% increase in the basal cAMP levels, but it did not affect intracellular calcium concentrations. The involvement of GPR55, TRPA1, and COX-2 in the AM251 mechanism of action was excluded. The combination of AM251 with celecoxib produced a synergistic antitumor activity, although the mechanism underlying this effect remains to be elucidated. This study provides the first evidence of a proapoptotic effect and G2/M cell cycle arrest of AM251 on A375 cells. This compound may be a potential prototype for the development of promising diarylpyrazole derivatives to be evaluated in human cutaneous melanoma.

  5. DNA fragmentation and cell cycle arrest: a hallmark of apoptosis induced by Ruta graveolens in human colon cancer cells.

    PubMed

    Arora, Shagun; Tandon, Simran

    2015-01-01

    In the present study, we investigated the anti-cancer effect of various potencies of Ruta graveolens (Ruta) on COLO-205 cell line, as evidenced by cytotoxicity, migration, clonogenecity, morphological and biochemical changes and modification in the levels of genes associated with apoptosis and cell cycle. On treatment of COLO-205 cells maximal effects were seen with mother tincture (MT) and 30C potencies, wherein decrease in cell viability along with reduced clonogenecity and migration capabilities were noted. In addition morphological and biochemical alterations such as nuclear changes (fragmented nuclei with condensed chromatin) and DNA ladder-like pattern (increased amount of fragmented DNA) in COLO-205 cells indicating apoptotic related cell death were seen. The expression of apoptosis and cell-cycle related regulatory genes assessed by reverse transcriptase-PCR revealed an up-regulation of caspase 9, caspase-3, Bax, p21 and p27 expression and down-regulation of Bcl-2 expression in treated cells. The mode of cell death was suggestive of intrinsic apoptotic pathway along with cell cycle arrest at the G2/M of the cell cycle. Our findings indicate that phytochemicals present in Ruta showed potential for natural therapeutic product development for colon carcinoma.

  6. Cytotoxicity of atropine to human corneal epithelial cells by inducing cell cycle arrest and mitochondrion-dependent apoptosis.

    PubMed

    Tian, Cheng-Lei; Wen, Qian; Fan, Ting-Jun

    2015-10-01

    Atropine is an anticholinergic drug for mydriasis in eye clinic, and its abuse might be cytotoxic to the cornea and result in blurred vision. However, the cytotoxicity of atropine to the cornea and its cellular and molecular mechanisms remain unknown. In this study, we investigated the cytotoxicity of atropine to corneal epithelium and its underlying mechanisms using an in vitro model of non-transfected human corneal epithelial (HCEP) cells. Our results showed that atropine, above the concentration of 0.3125 g/l (1/32 of its therapeutic dosage in eye clinic), had a dose- and time-dependent toxicity to HCEP cells by inducing morphological abnormality, cytopathic effect, viability decline, and proliferation retardation. Moreover, the proliferation-retarding effect of atropine on the cells was achieved by inducing G1/S phase arrest and downregulation of E-cadherin and β-catenin. Besides, atropine also had an apoptosis-inducing effect on the cells by inducing phosphatidylserine externalization, plasma membrane permeability elevation, DNA fragmentation and apoptotic body formation. Furthermore, atropine could also induce activations of caspase-2, -3 and -9, disruption of mitochondrial transmembrane potential, downregulation of Bcl-2 and Bcl-xL, upregulation of Bax and Bad, and upregulation of cytoplasmic cytochrome c and apoptosis-inducing factor, implying a death receptor-mediated mitochondrion-dependent pathway is most probably involved in the apoptosis of HCEP cells induced by atropine. Taken together, our results suggest that atropine has remarkable cytotoxicity to HCEP cells by inducing cell cycle arrest and death receptor-mediated mitochondrion-dependent apoptosis.

  7. microRNA-449a functions as a tumor suppressor in neuroblastoma through inducing cell differentiation and cell cycle arrest

    PubMed Central

    Zhao, Zhenze; Ma, Xiuye; Sung, Derek; Li, Monica; Kosti, Adam; Lin, Gregory; Chen, Yidong; Pertsemlidis, Alexander; Hsiao, Tzu-Hung; Du, Liqin

    2015-01-01

    microRNA-449a (miR-449a) has been identified to function as a tumor suppressor in several types of cancers. However, the role of miR-449a in neuroblastoma has not been intensively investigated. We recently found that the overexpression of miR-449a significantly induces neuroblastoma cell differentiation, suggesting its potential tumor suppressor function in neuroblastoma. In this study, we further investigated the mechanisms underlying the tumor suppressive function of miR-449a in neuroblastoma. We observed that miR-449a inhibits neuroblastoma cell survival and growth through 2 mechanisms—inducing cell differentiation and cell cycle arrest. Our comprehensive investigations on the dissection of the target genes of miR-449a revealed that 3 novel targets- MFAP4, PKP4 and TSEN15 -play important roles in mediating its differentiation-inducing function. In addition, we further found that its function in inducing cell cycle arrest involves down-regulating its direct targets CDK6 and LEF1. To determine the clinical significance of the miR-449a-mediated tumor suppressive mechanism, we examined the correlation between the expression of these 5 target genes in neuroblastoma tumor specimens and the survival of neuroblastoma patients. Remarkably, we noted that high tumor expression levels of all the 3 miR-449a target genes involved in regulating cell differentiation, but not the target genes involved in regulating cell cycle, are significantly correlated with poor survival of neuroblastoma patients. These results suggest the critical role of the differentiation-inducing function of miR-449a in determining neuroblastoma progression. Overall, our study provides the first comprehensive characterization of the tumor-suppressive function of miR-449a in neuroblastoma, and reveals the potential clinical significance of the miR-449a-mediated tumor suppressive pathway in neuroblastoma prognosis. PMID:25760387

  8. Cypermethrin Induces Macrophages Death through Cell Cycle Arrest and Oxidative Stress-Mediated JNK/ERK Signaling Regulated Apoptosis.

    PubMed

    Huang, Fang; Liu, Qiaoyun; Xie, Shujun; Xu, Jian; Huang, Bo; Wu, Yihua; Xia, Dajing

    2016-06-17

    Cypermethrin is one of the most highly effective synthetic pyrethroid insecticides. The toxicity of cypermethrin to the reproductive and nervous systems has been well studied. However, little is known about the toxic effect of cypermethrin on immune cells such as macrophages. Here, we investigated the cytotoxicity of cypermethrin on macrophages and the underlying molecular mechanisms. We found that cypermethrin reduced cell viability and induced apoptosis in RAW 264.7 cells. Cypermethrin also increased reactive oxygen species (ROS) production and DNA damage in a dose-dependent manner. Moreover, cypermethrin-induced G1 cell cycle arrest was associated with an enhanced expression of p21, wild-type p53, and down-regulation of cyclin D1, cyclin E and CDK4. In addition, cypermethrin treatment activated MAPK signal pathways by inducing c-Jun N-terminal kinase (JNK) and extracellular regulated protein kinases 1/2 ERK1/2 phosphorylation, and increased the cleaved poly ADP-ribose polymerase (PARP). Further, pretreatment with antioxidant N-acetylcysteine (NAC) effectively abrogated cypermethrin-induced cell cytotoxicity, G1 cell cycle arrest, DNA damage, PARP activity, and JNK and ERK1/2 activation. The specific JNK inhibitor (SP600125) and ERK1/2 inhibitor (PD98059) effectively reversed the phosphorylation level of JNK and ERK1/2, and attenuated the apoptosis. Taken together, these data suggested that cypermethrin caused immune cell death via inducing cell cycle arrest and apoptosis regulated by ROS-mediated JNK/ERK pathway.

  9. PLK1 blockade enhances therapeutic effects of radiation by inducing cell cycle arrest at the mitotic phase.

    PubMed

    Inoue, Minoru; Yoshimura, Michio; Kobayashi, Minoru; Morinibu, Akiyo; Itasaka, Satoshi; Hiraoka, Masahiro; Harada, Hiroshi

    2015-10-27

    The cytotoxicity of ionizing radiation depends on the cell cycle phase; therefore, its pharmacological manipulation, especially the induction of cell cycle arrest at the radiosensitive mitotic-phase (M-phase), has been attempted for effective radiation therapy. Polo-like kinase 1 (PLK1) is a serine/threonine kinase that functions in mitotic progression, and is now recognized as a potential target for radiosensitization. We herein investigated whether PLK1 blockade enhanced the cytotoxic effects of radiation by modulating cell cycle phases of cancer cells using the novel small molecule inhibitor of PLK1, TAK-960. The TAK-960 treatment exhibited radiosensitizing effects in vitro, especially when it increased the proportion of M-phase cells. TAK-960 did not sensitize cancer cells to radiation when an insufficient amount of time was provided to induce mitotic arrest. The overexpression of a PLK1 mutant, PLK1-R136G&T210D, which was confirmed to cancel the TAK-960-mediated increase in the proportion of mitotic cells, abrogated the radiosensitizing effects of TAK-960. A tumor growth delay assay also demonstrated that the radiosensitizing effects of TAK-960 depended on an increase in the proportion of M-phase cells. These results provide a rational basis for targeting PLK1 for radiosensitization when considering the therapeutic time window for M-phase arrest as the best timing for radiation treatments.

  10. Cypermethrin Induces Macrophages Death through Cell Cycle Arrest and Oxidative Stress-Mediated JNK/ERK Signaling Regulated Apoptosis

    PubMed Central

    Huang, Fang; Liu, Qiaoyun; Xie, Shujun; Xu, Jian; Huang, Bo; Wu, Yihua; Xia, Dajing

    2016-01-01

    Cypermethrin is one of the most highly effective synthetic pyrethroid insecticides. The toxicity of cypermethrin to the reproductive and nervous systems has been well studied. However, little is known about the toxic effect of cypermethrin on immune cells such as macrophages. Here, we investigated the cytotoxicity of cypermethrin on macrophages and the underlying molecular mechanisms. We found that cypermethrin reduced cell viability and induced apoptosis in RAW 264.7 cells. Cypermethrin also increased reactive oxygen species (ROS) production and DNA damage in a dose-dependent manner. Moreover, cypermethrin-induced G1 cell cycle arrest was associated with an enhanced expression of p21, wild-type p53, and down-regulation of cyclin D1, cyclin E and CDK4. In addition, cypermethrin treatment activated MAPK signal pathways by inducing c-Jun N-terminal kinase (JNK) and extracellular regulated protein kinases 1/2 ERK1/2 phosphorylation, and increased the cleaved poly ADP-ribose polymerase (PARP). Further, pretreatment with antioxidant N-acetylcysteine (NAC) effectively abrogated cypermethrin-induced cell cytotoxicity, G1 cell cycle arrest, DNA damage, PARP activity, and JNK and ERK1/2 activation. The specific JNK inhibitor (SP600125) and ERK1/2 inhibitor (PD98059) effectively reversed the phosphorylation level of JNK and ERK1/2, and attenuated the apoptosis. Taken together, these data suggested that cypermethrin caused immune cell death via inducing cell cycle arrest and apoptosis regulated by ROS-mediated JNK/ERK pathway. PMID:27322250

  11. Abnormal expression of TIP30 and arrested nucleocytoplasmic transport within oligodendrocyte precursor cells in multiple sclerosis

    PubMed Central

    Nakahara, Jin; Kanekura, Kohsuke; Nawa, Mikiro; Aiso, Sadakazu; Suzuki, Norihiro

    2008-01-01

    Oligodendrocyte precursor cells (OPCs) persist near the demyelinated axons arising in MS but inefficiently differentiate into oligodendrocytes and remyelinate these axons. The pathogenesis of differentiation failure remains elusive. We initially hypothesized that injured axons fail to present Contactin, a positive ligand for the oligodendroglial Notch1 receptor to induce myelination, and thus tracked axoglial Contactin/Notch1 signaling in situ, using immunohistochemistry in brain tissue from MS patients containing chronic demyelinated lesions. Instead, we found that Contactin was saturated on demyelinated axons, Notch1-positive OPCs accumulated in Contactin-positive lesions, and the receptor was engaged, as demonstrated by cleavage to Notch1-intracellular domain (NICD). However, nuclear translocalization of NICD, required for myelinogenesis, was virtually absent in these cells. NICD and related proteins carrying nuclear localization signals were associated with the nuclear transporter Importin but were trapped in the cytoplasm. Abnormal expression of TIP30, a direct inhibitor of Importin, was observed in these OPCs. Overexpression of TIP30 in a rat OPC cell line resulted in cytoplasmic entrapment of NICD and arrest of differentiation upon stimulation with Contactin-Fc. Our results suggest that extracellular inhibitory factors as well as an intrinsic nucleocytoplasmic transport blockade within OPCs may be involved in the pathogenesis of remyelination failure in MS. PMID:19104151

  12. Arrested cell proliferation through cysteine protease activity of eukaryotic ribosomal protein S4.

    PubMed

    Yadaiah, Madasu; Sudhamalla, Babu; Rao, P Nageswara; Roy, Karnati R; Ramakrishna, Dasari; Hussain Syed, Gulam; Ramaiah, Kolluru V A; Bhuyan, Abani K

    2013-02-01

    S4 is an integral protein of the smaller subunit of cytosolic ribosome. In prokaryotes, it regulates the synthesis of ribosomal proteins by feedback inhibition of the α-operon gene expression, and it facilitates ribosomal RNA synthesis by direct binding to RNA polymerase. However, functional roles of S4 in eukaryotes are poorly understood, although its deficiency in humans is thought to produce Turner syndrome. We report here that wheat S4 is a cysteine protease capable of abrogating total protein synthesis in an actively translating cell-free system of rabbit reticulocytes. The translation-blocked medium, imaged by atomic force microscopy, scanning electron microscopy, and transmission electron microscopy, shows dispersed polysomes, and the disbanded polyribosome elements aggregate to form larger bodies. We also show that human embryonic kidney cells transfected with recombinant wheat S4 are unable to grow and proliferate. The mutant S4 protein, where the putative active site residue Cys 41 is replaced by a phenylalanine, can neither suppress protein synthesis nor arrest cell proliferation, suggesting that the observed phenomenon arises from the cysteine protease attribute of S4. The results also inspire many questions concerning in vivo significance of extraribosomal roles of eukaryotic S4 performed through its protease activity.

  13. Silencing of survivin by YM155 induces apoptosis and growth arrest in hepatocellular carcinoma cells

    PubMed Central

    ZHANG, CHANGHE; CAO, XIAOFEI; GEI, YONGXIANG; WANG, YONG; LIU, GUIYUAN; CHENG, GUOCHANG; LIU, QINGHONG

    2015-01-01

    Survivin overactivation is a frequent event in human hepatocellular carcinoma (HCC), due to its function in the induction of hepatocyte proliferation and apoptotic dysfunction. Recently, a novel survivin inhibitor named YM155, has demonstrated broad antitumor effects against various malignant tumors. Therefore, the present study aimed to explore how this agent may impact on HCC and elucidate its underlying mechanism of action. Immunohistochemical analysis was performed on 8 specimens of human HCC, to assess the protein expression of survivin and phosphorylated retinoblastoma tumor suppressor (p-Rb). In addition, in vitro, HepG2 and Huh7 human HCC cell lines were exposed to 100 µM YM155 for up to 72 h and the cell viability was subsequently determined using MTT assay. Furthermore, the apoptotic status of YM155-treated HCC cells was investigated by flow cytometry, and the protein levels of survivin, procaspase-3 and p-Rb in YM155-treated HCC cells were assessed by immunoblotting analysis. The results demonstrated that HCC specimens expressed high levels of survivin and p-Rb protein compared with those of adjacent noncancerous liver tissues. In vitro, YM155 significantly induced HCC cell apoptosis and growth arrest. At the protein level, YM155 markedly inhibited survivin and p-Rb expression, and elevated procaspase-3. YM155 demonstrated significant antitumor effects on HCC cells in the present study. These effects were associated with its anti-proliferative and apoptosis-induction activities. YM155 requires further investigation as a novel agent for potential use as a therapeutic strategy for the treatment of HCC. PMID:26622722

  14. Clove extract inhibits tumor growth and promotes cell cycle arrest and apoptosis.

    PubMed

    Liu, Haizhou; Schmitz, John C; Wei, Jianteng; Cao, Shousong; Beumer, Jan H; Strychor, Sandra; Cheng, Linyou; Liu, Ming; Wang, Cuicui; Wu, Ning; Zhao, Xiangzhong; Zhang, Yuyan; Liao, Joshua; Chu, Edward; Lin, Xiukun

    2014-01-01

    Cloves (Syzygium aromaticum) have been used as a traditional Chinese medicinal herb for thousands of years. Cloves possess antiseptic, antibacterial, antifungal, and antiviral properties, but their potential anticancer activity remains unknown. In this study, we investigated the in vitro and in vivo antitumor effects and biological mechanisms of ethyl acetate extract of cloves (EAEC) and the potential bioactive components responsible for its antitumor activity. The effects of EAEC on cell growth, cell cycle distribution, and apoptosis were investigated using human cancer cell lines. The molecular changes associated with the effects of EAEC were analyzed by Western blot and (qRT)-PCR analysis. The in vivo effect of EAEC and its bioactive component was investigated using the HT-29 tumor xenograft model. We identified oleanolic acid (OA) as one of the components of EAEC responsible for its antitumor activity. Both EAEC and OA display cytotoxicity against several human cancer cell lines. Interestingly, EAEC was superior to OA and the chemotherapeutic agent 5-fluorouracil at suppressing growth of colon tumor xenografts. EAEC promoted G0/G1 cell cycle arrest and induced apoptosis in a dose-dependent manner. Treatment with EAEC and OA selectively increased protein expression of p21(WAF1/Cip1) and γ-H2AX and downregulated expression of cell cycle-regulated proteins. Moreover, many of these changes were at the mRNA level, suggesting transcriptional regulation by EAEC treatment. Our results demonstrate that clove extract may represent a novel therapeutic herb for the treatment of colorectal cancer, and OA appears to be one of the bioactive components.

  15. Methyl Sartortuoate Inhibits Colon Cancer Cell Growth by Inducing Apoptosis and G2/M-Phase Arrest.

    PubMed

    Lan, Qiusheng; Li, Shoufeng; Lai, Wei; Xu, Heyang; Zhang, Yang; Zeng, Yujie; Lan, Wenjian; Chu, Zhonghua

    2015-08-17

    The potential anti-neoplastic activity of terpenoids is of continued interest. In this study, we investigate whether methyl sartortuoate, a terpenoid isolated from soft coral, induced cell cycle arrest and apoptosis in a human colon cancer cell line. Culture studies found that methyl sartortuoate inhibited colon cancer cell (LoVo and RKO) growth and caused apoptotic death in a concentration- and time-dependent manner, by activation of caspase-8, caspase-9, caspase-3, p53 and Bax, and inactivation of B-cell lymphoma 2 (Bcl-2) apoptosis regulating proteins. Methyl sartortuoate treatment led to reduced expression of cdc2 and up-regulated p21 and p53, suggesting that Methyl sartortuoate induced G2-M arrest through modulation of p53/p21/cdc2 pathways. Methyl sartortuoate also up-regulated phospho-JNK and phospho-p38 expression levels. This resulted in cell cycle arrest at the G2-M phase and apoptosis in LoVo and RKO cells. Treatment with the JNK inhibitor SP600125 and the p38 MAPK inhibitor SB203580 prevented methyl sartortuoate-induced apoptosis in LoVo cells. Moreover, methyl sartortuoate also prevented neoplasm growth in NOD-SCID nude mice inoculated with LoVo cells. Taken together, these findings suggest that methyl sartortuoate is capable of leading to activation of caspase-8, -9, -3, increasing p53 and Bax/Bcl-2 ratio apoptosis through MAPK-dependent apoptosis and results in G2-M phase arrest in LoVo and RKO cells. Thus, methyl sartortuoate may be a promising anticancer candidate.

  16. Purified Brominated Indole Derivatives from Dicathais orbita Induce Apoptosis and Cell Cycle Arrest in Colorectal Cancer Cell Lines

    PubMed Central

    Esmaeelian, Babak; Benkendorff, Kirsten; Johnston, Martin R.; Abbott, Catherine A.

    2013-01-01

    Dicathais orbita is a large Australian marine gastropod known to produce bioactive compounds with anticancer properties. In this research, we used bioassay guided fractionation from the egg mass extract of D. orbita using flash column chromatography and identified fractions containing tyrindoleninone and 6-bromoisatin as the most active against colon cancer cells HT29 and Caco-2. Liquid chromatography coupled with mass spectrometry (LCMS) and 1H NMR were used to characterize the purity and chemical composition of the isolated compounds. An MTT assay was used to determine effects on cell viability. Necrosis and apoptosis induction using caspase/LDH assay and flow cytometry (PI/Annexin-V) and cell cycle analysis were also investigated. Our results show that semi-purified 6-bromoisatin had the highest anti-cancer activity by inhibiting cell viability (IC50 = ~100 µM) and increasing caspase 3/7 activity in both of the cell lines at low concentration. The fraction containing 6-bromoisatin induced 77.6% apoptosis and arrested 25.7% of the cells in G2/M phase of cell cycle in HT29 cells. Tyrindoleninone was less potent but significantly decreased the viability of HT29 cells at IC50 = 390 µM and induced apoptosis at 195 µM by increasing caspase 3/7 activity in these cells. This research will facilitate the development of these molluscan natural products as novel complementary medicines for colorectal cancer. PMID:24152558

  17. Notch3 overexpression causes arrest of cell cycle progression by inducing Cdh1 expression in human breast cancer cells.

    PubMed

    Chen, Chun-Fa; Dou, Xiao-Wei; Liang, Yuan-Ke; Lin, Hao-Yu; Bai, Jing-Wen; Zhang, Xi-Xun; Wei, Xiao-Long; Li, Yao-Chen; Zhang, Guo-Jun

    2016-01-01

    Uncontrolled cell proliferation, genomic instability and cancer are closely related to the abnormal activation of the cell cycle. Therefore, blocking the cell cycle of cancer cells has become one of the key goals for treating malignancies. Unfortunately, the factors affecting cell cycle progression remain largely unknown. In this study, we have explored the effects of Notch3 on the cell cycle in breast cancer cell lines by 3 methods: overexpressing the intra-cellular domain of Notch3 (N3ICD), knocking-down Notch3 by RNA interference, and using X-ray radiation exposure. The results revealed that overexpression of Notch3 arrested the cell cycle at the G0/G1 phase, and inhibited the proliferation and colony-formation rate in the breast cancer cell line, MDA-MB-231. Furthermore, overexpressing N3ICD upregulated Cdh1 expression and resulted in p27(Kip) accumulation by accelerating Skp2 degradation. Conversely, silencing of Notch3 in the breast cancer cell line, MCF-7, caused a decrease in expression levels of Cdh1 and p27(Kip) at both the protein and mRNA levels, while the expression of Skp2 only increased at the protein level. Correspondingly, there was an increase in the percentage of cells in the G0/G1 phase and an elevated proliferative ability and colony-formation rate, which may be caused by alterations of the Cdh1/Skp2/p27 axis. These results were also supported by exposing MDA-MB-231 cells or MCF-7 treated with siN3 to X-irradiation at various doses. Overall, our data showed that overexpression of N3ICD upregulated the expression of Cdh1 and caused p27(Kip) accumulation by accelerating Skp2 degradation, which in turn led to cell cycle arrest at the G0/G1 phase, in the context of proliferating breast cancer cell lines. These findings help to illuminate the precision therapy targeted to cell cycle progression, required for cancer treatment.

  18. Effects of ZnO nanoparticles in plants: Cytotoxicity, genotoxicity, deregulation of antioxidant defenses, and cell-cycle arrest.

    PubMed

    Ghosh, Manosij; Jana, Aditi; Sinha, Sonali; Jothiramajayam, Manivannan; Nag, Anish; Chakraborty, Anirban; Mukherjee, Amitava; Mukherjee, Anita

    2016-09-01

    Cytotoxicity, genotoxicity, and biochemical effects were evaluated in the plants Allium cepa, Nicotiana tabacum, and Vicia faba following exposure to ZnO nanoparticles (np; diameter, ∼85nm). In the root meristems of Allium cepa cells, we observed loss of membrane integrity, increased chromosome aberrations, micronucleus formation, DNA strand breaks, and cell-cycle arrest at the G2/M checkpoint. In Vicia faba and Nicotiana tabacum, we observed increased intracellular ROS production, lipid peroxidation, and activities of some antioxidant enzymes. TEM images revealed gross morphological alterations and internalization of the np. Our findings provide evidence of ZnO np toxicity, characterized by deregulation of components of ROS-antioxidant machinery, leading to DNA damage, cell-cycle arrest, and cell death. These plants, especially Allium cepa, are reliable systems for assessment of np toxicology. PMID:27542712

  19. Tocotrienol-rich fraction of palm oil induces cell cycle arrest and apoptosis selectively in human prostate cancer cells

    SciTech Connect

    Srivastava, Janmejai K.; Gupta, Sanjay . E-mail: sanjay.gupta@case.edu

    2006-07-28

    One of the requisite of cancer chemopreventive agent is elimination of damaged or malignant cells through cell cycle inhibition or induction of apoptosis without affecting normal cells. In this study, employing normal human prostate epithelial cells (PrEC), virally transformed normal human prostate epithelial cells (PZ-HPV-7), and human prostate cancer cells (LNCaP, DU145, and PC-3), we evaluated the growth-inhibitory and apoptotic effects of tocotrienol-rich fraction (TRF) extracted from palm oil. TRF treatment to PrEC and PZ-HPV-7 resulted in almost identical growth-inhibitory responses of low magnitude. In sharp contrast, TRF treatment resulted in significant decreases in cell viability and colony formation in all three prostate cancer cell lines. The IC{sub 5} values after 24 h TRF treatment in LNCaP, PC-3, and DU145 cells were in the order 16.5, 17.5, and 22.0 {mu}g/ml. TRF treatment resulted in significant apoptosis in all the cell lines as evident from (i) DNA fragmentation (ii) fluorescence microscopy, and (iii) cell death detection ELISA, whereas the PrEC and PZ-HPV-7 cells did not undergo apoptosis, but showed modestly decreased cell viability only at a high dose of 80 {mu}g/ml. In cell cycle analysis, TRF (10-40 {mu}g/ml) resulted in a dose-dependent G0/G1 phase arrest and sub G1 accumulation in all three cancer cell lines but not in PZ-HPV-7 cells. These results suggest that the palm oil derivative TRF is capable of selectively inhibiting cellular proliferation and accelerating apoptotic events in prostate cancer cells. TRF offers significant promise as a chemopreventive and/or therapeutic agent against prostate cancer.

  20. Developmental arrest of T cells in RpL22-deficient mice is dependent upon multiple p53 effectors1

    PubMed Central

    Stadanlick, Jason E.; Zhang, Zhiqiang; Lee, Sang-Yun; Hemann, Mike; Biery, Matthew; Carleton, Michael O.; Zambetti, Gerard P.; Anderson, Stephen J.; Oravecz, Tamas; Wiest, David L.

    2011-01-01

    αβ and γδ lineage T cells are thought to arise from a common CD4−CD8− progenitor in the thymus. However, the molecular pathways controlling fate selection and maturation of these two lineages remain poorly understood. We have demonstrated recently that a ubiquitously expressed ribosomal protein, Rpl22, is selectively required for the development of αβ lineage T cells. Germline ablation of Rpl22 impairs development of αβ lineage, but not γδ lineage, T cells through activation of a p53-dependent checkpoint. In this study, we investigate the downstream effectors employed by p53 to impair T cell development. We found that many p53 targets were induced in Rpl22−/− thymocytes, including miR-34a, PUMA, p21waf, Bax, and Noxa. Notably, the pro-apoptotic factor Bim, while not a direct p53 target, was also strongly induced in Rpl22−/− T cells. Gain-of-function analysis indicated that overexpression of miR-34a caused a developmental arrest reminiscent of that induced by p53 in Rpl22-deficient T cells; however, only a few p53 targets, when individually ablated by gene targeting or knockdown, alleviated developmental arrest. Co-elimination of PUMA and Bim resulted in a nearly complete restoration of development of Rpl22−/− thymocytes, indicating that p53-mediated arrest is enforced principally through effects on cell survival. Surprisingly, co-elimination of the primary p53 regulators of cell cycle arrest (p21waf) and apoptosis (PUMA) actually abrogated the partial rescue caused by loss of PUMA alone, suggesting that the G1 checkpoint protein p21waf might actually facilitate thymocyte development in some contexts. PMID:21690328

  1. Leaf Extracts of Calocedrus formosana (Florin) Induce G2/M Cell Cycle Arrest and Apoptosis in Human Bladder Cancer Cells

    PubMed Central

    Yuan, Sheau-Yun; Lin, Chi-Chen; Hsu, Shih-Lan; Cheng, Ya-Wen; Wu, Jyh-Horng; Cheng, Chen-Li; Yang, Chi-Rei

    2011-01-01

    Calocedrus formosana (Florin) bark acetone/ethylacetate extracts are known to exert an antitumor effect on some human cancer cell lines, but the mechanism is yet to be defined. The aim of this study was to determine the effects of Florin leaf methanol extracts on the growth and apoptosis of human bladder cancer cell lines. MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay showed that the growth of these bladder cancer cells was potently inhibited by the Florin leaf extracts. The cell cycle of these extract-treated cells (TCCSUP cells) was arrested at the G2/M phase as determined by flow cytometry. Western blot analysis revealed the increases of cyclin B1 and Cdc2 kinase levels, alone with the decrease of phosphorylated Cdc2 kinase, after treating these cells with the extracts. An immunofluorescence assessment of β-tubulin showed decreased levels of polymerized tubulin in treated cells. However, the proteolytic cleavage of poly ADP-ribose polymerase and the activation of caspase-3/-8/-9 were all increased upon treatments of extracts. The concurrent increase of Bax and decrease of Bcl-2 levels indicated that the extracts could induce apoptosis in these treated cells. Taken together, these results suggest that the Florin leaf extracts may be an effective antibladder cancer agent. PMID:21760824

  2. Amino-functionalized nanoparticles as inhibitors of mTOR and inducers of cell cycle arrest in leukemia cells.

    PubMed

    Loos, Cornelia; Syrovets, Tatiana; Musyanovych, Anna; Mailänder, Volker; Landfester, Katharina; Simmet, Thomas

    2014-02-01

    Activation of the mammalian target of rapamycin (mTOR) has been implicated in anticancer drug resistance, type 2 diabetes, and aging. Here, we show that surface functionalization of polystyrene nanoparticles with amino groups (PS-NH2), but not with carboxyl groups (PS-COOH), induces G2 cell-cycle arrest and inhibition of proliferation in three leukemia cell lines. Besides, PS-NH2 inhibit angiogenesis and proliferation of leukemia cells xenografted onto the chick chorioallantoic membrane. At the molecular level, PS-NH2 inhibit, whereas PS-COOH activate mTOR signaling in leukemia cells. Consistently, PS-NH2 block activation of the mTOR downstream targets, Akt and p70 ribosomal S6 kinase 1, and induce overexpression of the cell-cycle regulator p21(Cip1/Waf1) and degradation of cyclin B1. After addition, both types of particles rapidly induce autophagy in leukemia cells. Yet, only in PS-NH2-treated cells, acidic vesicular organelles show elevated pH and impaired processing of procathepsin B. Moreover, solely in PS-NH2-treated cells, autophagy is followed by permeabilization of acidic vesicular organelles and induction of apoptosis. By contrast, primary macrophages, which do not exhibit activated mTOR signaling, proved relatively resistant to PS-NH2-induced toxicity. These data indicate that functionalized nanoparticles can be used to control activation of mTOR signaling pathways, and to influence proliferation and viability of malignant cells.

  3. Amino-functionalized nanoparticles as inhibitors of mTOR and inducers of cell cycle arrest in leukemia cells.

    PubMed

    Loos, Cornelia; Syrovets, Tatiana; Musyanovych, Anna; Mailänder, Volker; Landfester, Katharina; Simmet, Thomas

    2014-02-01

    Activation of the mammalian target of rapamycin (mTOR) has been implicated in anticancer drug resistance, type 2 diabetes, and aging. Here, we show that surface functionalization of polystyrene nanoparticles with amino groups (PS-NH2), but not with carboxyl groups (PS-COOH), induces G2 cell-cycle arrest and inhibition of proliferation in three leukemia cell lines. Besides, PS-NH2 inhibit angiogenesis and proliferation of leukemia cells xenografted onto the chick chorioallantoic membrane. At the molecular level, PS-NH2 inhibit, whereas PS-COOH activate mTOR signaling in leukemia cells. Consistently, PS-NH2 block activation of the mTOR downstream targets, Akt and p70 ribosomal S6 kinase 1, and induce overexpression of the cell-cycle regulator p21(Cip1/Waf1) and degradation of cyclin B1. After addition, both types of particles rapidly induce autophagy in leukemia cells. Yet, only in PS-NH2-treated cells, acidic vesicular organelles show elevated pH and impaired processing of procathepsin B. Moreover, solely in PS-NH2-treated cells, autophagy is followed by permeabilization of acidic vesicular organelles and induction of apoptosis. By contrast, primary macrophages, which do not exhibit activated mTOR signaling, proved relatively resistant to PS-NH2-induced toxicity. These data indicate that functionalized nanoparticles can be used to control activation of mTOR signaling pathways, and to influence proliferation and viability of malignant cells. PMID:24331713

  4. Resveratrol Induces Cell Cycle Arrest and Apoptosis in Malignant NK Cells via JAK2/STAT3 Pathway Inhibition

    PubMed Central

    Quoc Trung, Ly; Espinoza, J. Luis; Takami, Akiyoshi; Nakao, Shinji

    2013-01-01

    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. PMID:23372833

  5. Identification of key factors conquering developmental arrest of somatic cell cloned embryos by combining embryo biopsy and single-cell sequencing

    PubMed Central

    Liu, Wenqiang; Liu, Xiaoyu; Wang, Chenfei; Gao, Yawei; Gao, Rui; Kou, Xiaochen; Zhao, Yanhong; Li, Jingyi; Wu, You; Xiu, Wenchao; Wang, Su; Yin, Jiqing; Liu, Wei; Cai, Tao; Wang, Hong; Zhang, Yong; Gao, Shaorong

    2016-01-01

    Differentiated somatic cells can be reprogrammed into totipotent embryos through somatic cell nuclear transfer. However, most cloned embryos arrest at early stages and the underlying molecular mechanism remains largely unexplored. Here, we first developed a somatic cell nuclear transfer embryo biopsy system at two- or four-cell stage, which allows us to trace the developmental fate of the biopsied embryos precisely. Then, through single-cell transcriptome sequencing of somatic cell nuclear transfer embryos with different developmental fates, we identified that inactivation of Kdm4b, a histone H3 lysine 9 trimethylation demethylase, functions as a barrier for two-cell arrest of cloned embryos. Moreover, we discovered that inactivation of another histone demethylase Kdm5b accounts for the arrest of cloned embryos at the four-cell stage through single-cell analysis. Co-injection of Kdm4b and Kdm5b can restore transcriptional profiles of somatic cell nuclear transfer embryos and greatly improve the blastocyst development (over 95%) as well as the production of cloned mice. Our study therefore provides an effective approach to identify key factors responsible for the developmental arrest of somatic cell cloned embryos. PMID:27462457

  6. Identification of key factors conquering developmental arrest of somatic cell cloned embryos by combining embryo biopsy and single-cell sequencing.

    PubMed

    Liu, Wenqiang; Liu, Xiaoyu; Wang, Chenfei; Gao, Yawei; Gao, Rui; Kou, Xiaochen; Zhao, Yanhong; Li, Jingyi; Wu, You; Xiu, Wenchao; Wang, Su; Yin, Jiqing; Liu, Wei; Cai, Tao; Wang, Hong; Zhang, Yong; Gao, Shaorong

    2016-01-01

    Differentiated somatic cells can be reprogrammed into totipotent embryos through somatic cell nuclear transfer. However, most cloned embryos arrest at early stages and the underlying molecular mechanism remains largely unexplored. Here, we first developed a somatic cell nuclear transfer embryo biopsy system at two- or four-cell stage, which allows us to trace the developmental fate of the biopsied embryos precisely. Then, through single-cell transcriptome sequencing of somatic cell nuclear transfer embryos with different developmental fates, we identified that inactivation of Kdm4b, a histone H3 lysine 9 trimethylation demethylase, functions as a barrier for two-cell arrest of cloned embryos. Moreover, we discovered that inactivation of another histone demethylase Kdm5b accounts for the arrest of cloned embryos at the four-cell stage through single-cell analysis. Co-injection of Kdm4b and Kdm5b can restore transcriptional profiles of somatic cell nuclear transfer embryos and greatly improve the blastocyst development (over 95%) as well as the production of cloned mice. Our study therefore provides an effective approach to identify key factors responsible for the developmental arrest of somatic cell cloned embryos. PMID:27462457

  7. Polycomb Group Protein PHF1 Regulates p53-dependent Cell Growth Arrest and Apoptosis*

    PubMed Central

    Yang, Yang; Wang, Chenji; Zhang, Pingzhao; Gao, Kun; Wang, Dejie; Yu, Hongxiu; Zhang, Ting; Jiang, Sirui; Hexige, Saiyin; Hong, Zehui; Yasui, Akira; Liu, Jun O.; Huang, Haojie; Yu, Long

    2013-01-01

    Polycomb group protein PHF1 is well known as a component of a novel EED-EZH2·Polycomb repressive complex 2 complex and plays important roles in H3K27 methylation and Hox gene silencing. PHF1 is also involved in the response to DNA double-strand breaks in human cells, promotes nonhomologous end-joining processes through interaction with Ku70/Ku80. Here, we identified another function of PHF1 as a potential p53 pathway activator in a pathway screen using luminescence reporter assay. Subsequent studies showed PHF1 directly interacts with p53 proteins both in vivo and in vitro and co-localized in nucleus. PHF1 binds to the C-terminal regulatory domain of p53. Overexpression of PHF1 elevated p53 protein level and prolonged its turnover. Knockdown of PHF1 reduced p53 protein level and its target gene expression both in normal state and DNA damage response. Mechanically, PHF1 protects p53 proteins from MDM2-mediated ubiquitination and degradation. Furthermore, we showed that PHF1 regulates cell growth arrest and etoposide-induced apoptosis in a p53-dependent manner. Finally, PHF1 expression was significantly down-regulated in human breast cancer samples. Taken together, we establish PHF1 as a novel positive regulator of the p53 pathway. These data shed light on the potential roles of PHF1 in tumorigenesis and/or tumor progression. PMID:23150668

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

    PubMed

    Pfeuty, Benjamin

    2012-01-01

    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.

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

    PubMed Central

    Bailon-Moscoso, Natalia; González-Arévalo, Gabriela; Velásquez-Rojas, Gabriela; Malagon, Omar; Vidari, Giovanni; Zentella-Dehesa, Alejandro; Ratovitski, Edward A.; Ostrosky-Wegman, Patricia

    2015-01-01

    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. PMID:26309132

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

    PubMed

    Bailon-Moscoso, Natalia; González-Arévalo, Gabriela; Velásquez-Rojas, Gabriela; Malagon, Omar; Vidari, Giovanni; Zentella-Dehesa, Alejandro; Ratovitski, Edward A; Ostrosky-Wegman, Patricia

    2015-01-01

    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. PMID:26309132

  11. 13-Methyl-palmatrubine induces apoptosis and cell cycle arrest in A549 cells in vitro and in vivo

    PubMed Central

    Chen, Jingxian; Lu, Xingang; Lu, Chenghua; Wang, Chunying; Xu, Haizhu; Xu, Xiaoli; Gou, Haixin; Zhu, Bing; Du, Wangchun

    2016-01-01

    Corydalis yanhusuo, a well-known herbaceous plant, is commonly used in the treatment of inflammation, injury and pain. One natural agent isolated from Corydalis yanhusuo, 13-methyl-palmatrubine, was found to have a cytotoxic effect on cancer cells as reported in published studies. In the present study, we synthesized a potential anti-lung tumor agent, 13-methyl-palmatrubine and analyzed its activity. 13-Methyl-palmatrubine exhibited a cytotoxic effect on a panel of cancer cell lines in a time- and concentration-dependent manner. Among all the tested cancer cell lines, lung cancer A549 cells were most sensitive to 13-methyl-palmatrubine treatment. Meanwhile 13-methyl-palmatrubine showed less cytotoxicity in human normal cells. Our investigation revealed that 13-methyl-palmatrubine induced apoptosis and cell cycle arrest in A549 cells in a dose-dependent manner. Furthermore, 13-methyl-palmatrubine treatment caused activation of P38 and JNK pathways and blocked the EGFR pathway. In conclusion, our findings demonstrated that 13-methyl-palmatrubine inhibited the growth of A549 cells mediated by blocking of the EGFR signaling pathway and activation of the MAPK signaling pathway and provides a better understanding of the molecular mechanisms of 13-methyl-palmatrubine. PMID:27633656

  12. Gypensapogenin H, a novel dammarane-type triterpene induces cell cycle arrest and apoptosis on prostate cancer cells.

    PubMed

    Zhang, Xiao-Shu; Zhao, Chen; Tang, Wei-zhuo; Wu, Xiao-jun; Zhao, Yu-Qing

    2015-12-01

    Gypensapogenin H (GH) is a novel dammarane-type triterpenes obtained from hydrolyzate of total saponins from Gynostemma pentaphyllum and its anti-tumor activity has been studied in previous work. In this study, we report the effects of this compound on human prostate cancer cells (DU145 and 22RV-1). It significantly inhibited proliferation, decreased survival, led to G1 cell cycle arrest and induced apoptosis in both cell lines, while having lesser effect on the growth of normal human gastric mucosa cells (GES-1), embryonic kidney cells (HEK293) and lung fibroblast cells (MRC5). Consistent with these phenotypes, we observed decreased expression of the cell cycle-related proteins cyclinD1, and CDK4, and increased expression of p21 in GH-treated cells. Besides, the anti-apoptotic Bcl-2 protein decreased in a dose-dependent manner, while Bax, cleaved caspase-3 and -9 increased upon GH treatment. Taken together, these results indicated GH exerted promising anticancer activity, and may represent a potential agent for the treatment of prostate cancer.

  13. Terpenoids inhibit Candida albicans growth by affecting membrane integrity and arrest of cell cycle.

    PubMed

    Zore, Gajanan B; Thakre, Archana D; Jadhav, Sitaram; Karuppayil, S Mohan

    2011-10-15

    Anti-Candida potential of six terpenoids were evaluated in this study against various isolates of Candida albicans (n=39) and non-C. albicans (n=9) that are differentially susceptible to fluconazole. All the six terpenoids tested, showed excellent activity and were equally effective against isolates of Candida sps., tested in this study. Linalool and citral were the most effective ones, inhibiting all the isolates at ≤0.064% (v/v). Five among the six terpenoids tested were fungicidal. Time dependent kill curve assay showed that MFCs of linalool and eugenol were highly toxic to C. albicans, killing 99.9% inoculum within seven min of exposure, while that of citronellal, linalyl acetate and citral required 15min, 1h and 2h, respectively. FIC index values (Linalool - 0.140, benzyl benzoate - 0.156, eugenol - 0.265, citral - 0.281 and 0.312 for linalyl acetate and citronellal) and isobologram obtained by checker board assay showed that all the six terpenoids tested exhibit excellent synergistic activity with fluconazole against a fluconazole resistant strain of C. albicans. Terpenoids tested arrested C. albicans cells at different phases of the cell cycle i.e. linalool and LA at G1, citral and citronellal at S phase and benzyl benzoate at G2-M phase and induced apoptosis. Linalool, citral, citronellal and benzyl benzoate caused more than 50% inhibition of germ tube induction at 0.008%, while eugenol and LA required 0.032 and 0.016% (v/v) concentrations, respectively. MICs of all the terpenoids for the C. albicans growth were non toxic to HeLa cells. Terpenoids tested exhibited excellent activity against C. albicans yeast and hyphal form growth at the concentrations that are non toxic to HeLa cells. Terpenoids tested in this study may find use in antifungal chemotherapy, not only as antifungal agents but also as synergistic agents along with conventional drugs like fluconazole.

  14. TiO2 nanoparticles induce DNA double strand breaks and cell cycle arrest in human alveolar cells.

    PubMed

    Kansara, Krupa; Patel, Pal; Shah, Darshini; Shukla, Ritesh K; Singh, Sanjay; Kumar, Ashutosh; Dhawan, Alok

    2015-03-01

    TiO2 nanoparticles (NPs) have the second highest global annual production (∼3000 tons) among the metal-containing NPs. These NPs are used as photocatalysts for bacterial disinfection, and in various other consumer products including sunscreen, food packaging, therapeutics, biosensors, surface cleaning agents, and others. Humans are exposed to these NPs during synthesis (laboratory), manufacture (industry), and use (consumer products, devices, medicines, etc.), as well as through environmental exposures (disposal). Hence, there is great concern regarding the health effects caused by exposure to NPs and, in particular, to TiO2 NPs. In the present study, the genotoxic potential of TiO2 NPs in A549 cells was examined, focusing on their potential to induce ROS, different types of DNA damage, and cell cycle arrest. We show that TiO2 NPs can induce DNA damage and a corresponding increase in micronucleus frequency, as evident from the comet and cytokinesis-block micronucleus assays. We demonstrate that DNA damage may be attributed to increased oxidative stress and ROS generation. Furthermore, genomic and proteomic analyses showed increased expression of ATM, P53, and CdC-2 and decreased expression of ATR, H2AX, and Cyclin B1 in A549 cells, suggesting induction of DNA double strand breaks. The occurrence of double strand breaks was correlated with cell cycle arrest in G2/M phase. Overall, the results indicate the potential for genotoxicity following exposure to these TiO2 NPs, suggesting that use should be carefully monitored.

  15. Selective CDK7 inhibition with BS-181 suppresses cell proliferation and induces cell cycle arrest and apoptosis in gastric cancer

    PubMed Central

    Wang, Bo-Yong; Liu, Quan-Yan; Cao, Jun; Chen, Ji-Wei; Liu, Zhi-Su

    2016-01-01

    Cyclin-dependent kinase (CDK) family members have been considered as attractive therapeutic targets for cancer. In this study, we aim to investigate the anticancer effects of a selective CDK7 inhibitor, BS-181, in gastric cancer (GC) cell line. Human GC cells (BGC823) were cultured with or without BS-181 at different concentrations for 24–72 hours. BS-181 significantly reduced the activity of CDK7 with downregulation of cyclin D1 and XIAP in GC cells. Treatment with BS-181 induced cell cycle arrest and apoptosis. The expression of Bax and caspase-3 was significantly increased, while Bcl-2 expression was decreased in cells treated with BS-181. In addition, the inhibition of CDK7 with BS-181 resulted in reduced rates of proliferation, migration, and invasion of gastric cells. Those results demonstrated the anticancer activities of selective CDK7 inhibitor BS-181 in BGC823 cells, suggesting that CDK7 may serve as a novel therapeutic target or the treatment of GC. PMID:27042010

  16. Temozolomide may induce cell cycle arrest by interacting with URG4/URGCP in SH-SY5Y neuroblastoma cells.

    PubMed

    Çıtışlı, Veli; Dodurga, Yavuz; Eroğlu, Canan; Seçme, Mücahit; Avcı, Çığır Biray; Şatıroğlu-Tufan, N Lale

    2015-09-01

    Temozolomide (TMZ) is an alkylating drug used usually in glioma treatment by inducing the apoptosis in glioma cell. The aim of the study is to investigate the anticancer mechanism of TMZ in SH-SY5Y human neuroblastoma cell line. Cytotoxic effects of TMZ were determined by using XTT assay. IC50 doses in the SH-SY5Y were detected as 5 mM. Expression profiles of novel genes URG4/URGCP, CCND1, CCND2, CDK4, and BCL2 were determined by real-time PCR. The apoptotic effects of TMZ were evaluated with TUNEL method. Furthermore, effects of TMZ on colony formation and invasion were investigated in this study. It was observed that TMZ in SH-SY5Y cell line caused a significant decrease in the gene expressions of URG4/URGCP, CCND1, CCND2, CDK4, and BCL2. According to TUNEL assay results, TMZ markedly induced apoptosis in SH-SY5Y cell line. It was found that TMZ in SH-SY5Y cell line suppressed invasion and colony formation using matrigel invasion chamber and colony formation assay, respectively. To conclude, it is thought that TMZ demonstrates anticarcinogenesis activity by affecting cell cycle arrest, apoptosis, invasion, and colony formation on SH-SY5Y cells. TMZ may be an effective agent for treatment of neuroblastoma as a single or in combination with other drugs.

  17. PTEN/MMAC1/TEP1 suppresses the tumorigenicity and induces G1 cell cycle arrest in human glioblastoma cells

    PubMed Central

    Li, Da-Ming; Sun, Hong

    1998-01-01

    PTEN/MMAC1/TEP1 is a tumor suppressor that possesses intrinsic phosphatase activity. Deletions or mutations of its encoding gene are associated with a variety of human cancers. However, very little is known about the molecular mechanisms by which this important tumor suppressor regulates cell growth. Here, we show that PTEN expression potently suppressed the growth and tumorigenicity of human glioblastoma U87MG cells. The growth suppression activity of PTEN was mediated by its ability to block cell cycle progression in the G1 phase. Such an arrest correlated with a significant increase of the cell cycle kinase inhibitor p27KIP1 and a concomitant decrease in the activities of the G1 cyclin-dependent kinases. PTEN expression also led to the inhibition of Akt/protein kinase B, a serine-threonine kinase activated by the phosphatidylinositol 3-kinase (PI 3-kinase) signaling pathway. In addition, the effect of PTEN on p27KIP1 and the cell cycle can be mimicked by treatment of U87MG cells with LY294002, a selective inhibitor of PI 3-kinase. Taken together, our studies suggest that the PTEN tumor suppressor modulates G1 cell cycle progression through negatively regulating the PI 3-kinase/Akt signaling pathway, and one critical target of this signaling process is the cyclin-dependent kinase inhibitor p27KIP1. PMID:9860981

  18. Vapor of Volatile Oils from Litsea cubeba Seed Induces Apoptosis and Causes Cell Cycle Arrest in Lung Cancer Cells

    PubMed Central

    Seal, Soma; Chatterjee, Priyajit; Bhattacharya, Sushmita; Pal, Durba; Dasgupta, Suman; Kundu, Rakesh; Mukherjee, Sandip; Bhattacharya, Shelley; Bhuyan, Mantu; Bhattacharyya, Pranab R.; Baishya, Gakul; Barua, Nabin C.; Baruah, Pranab K.; Rao, Paruchuri G.; Bhattacharya, Samir

    2012-01-01

    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 Ser473 and Thr308; 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. PMID:23091605

  19. AB237. Human adipose derived stem cells induced cell apoptosis and S phase arrest in bladder tumor

    PubMed Central

    Yu, Xi; Su, Boxing; Ge, Peng; Wang, Zicheng; Li, Sen; Huang, Bingwei; Gong, Yanqing; Lin, Jian

    2016-01-01

    Background Mesenchymal stem cells (MSCs) had received much attention in recent years owing to their capacity to differentiate intaao many other cell types. Currently a lot of studies found that MSCs could secrete cytokines and chemokines which affect the growth of tumor cells. Adipose derived mesenchymal stem cells (ADSCs) could differentiate into a variety of different cells as well which were available easier. They could affect the growth of tumor cells, but the mechanism was not clear. We were trying to investigate their effect on bladder cancer cells growth to illustrate the possible mechanisms. Methods Transwell chamber co-culture was used to observe the effect of ADSCs on bladder cancer cell line T24 and EJ growth. T24 and EJ cells were cultured with condition medium of ADSCs and then recorded tumor cell activity by MTS assay. We used AnnexinV-PI double staining for tumor cell apoptosis, colony formation assay for tumor cell proliferation, wound healing for tumor cell migration, western blot for 5 detecting tumor cell associated protein expressing and molecular signaling pathways. Results The cell counting and colony formation assay showed ADSCs inhibited the proliferation of EJ and T24 cells. Cell viability assessment revealed that the secretions, in the form of conditioned medium, were able to decrease cancer cell viability. Wound-healing assay suggested ADSCs suppressed migration of T24 and EJ cells. Moreover, the results of the flow cytometry indicated that ADSCs were capable of inducing apoptosis of T24 cells and inducing S phase cell cycle arrest. Western blot revealed ADSCs increased the expression of cleaved Caspase-3 and cleaved PARP, indicating that ADSCs induced apoptosis in a caspase-dependent way. PTEN/PI3K/Akt pathway and Bcl-2 family proteins were involved in the mechanism of this reaction. Conclusions For the first time, we have provided the evidence to prove that ADSCs could obviously inhibit the proliferation of bladder cancer cells through

  20. Solanum tuberosum lectin inhibits Ehrlich ascites carcinoma cells growth by inducing apoptosis and G2/M cell cycle arrest.

    PubMed

    Kabir, Syed Rashel; Rahman, Md Musfikur; Amin, Ruhul; Karim, Md Rezaul; Mahmud, Zahid Hayat; Hossain, M Tofazzal

    2016-06-01

    Recently, a lectin was purified from the potato cultivated in Bangladesh locally known as Sheel. In the present study cytotoxicity of the lectin against Ehrlich ascites carcinoma (EAC) cells was studied by MTT assay in vitro in RPMI-1640 medium and 8.0-36.0 % cell growth inhibition was observed at the range of 2.5-160 μg/ml protein concentration when incubated for 24 h. The lectin-induced apoptosis in EAC cells was confirmed by fluorescence and optical microscope. The apoptotic cell death was also confirmed by using caspase inhibitors. Cells growth inhibition caused by the lectin (36 %) was remarkably decreased to 7.6 and 22.3 % respectively in the presence of caspase-3 and -8 inhibitors. RT-PCR was used to evaluate the expression of apoptosis-related genes Bcl-X, p53, and Bax. An intensive expression of Bcl-X gene was observed in untreated control EAC cells with the disappeared of the gene in Sheel-treated EAC cells. At the same time, Bax gene expression appeared only in Sheel-treated EAC cells and the expression level of the p53 gene was increased remarkable after the treatment of EAC cells with the lectin. The lectin showed strong agglutination activity against EAC cells. Flow cytometry was used to study the cell cycle phases of EAC cells and it was observed that the lectin arrested the G2/M phase. In conclusion, Sheel lectin inhibited EAC cells growth by inducing apoptosis. PMID:26733170

  1. Solanum tuberosum lectin inhibits Ehrlich ascites carcinoma cells growth by inducing apoptosis and G2/M cell cycle arrest.

    PubMed

    Kabir, Syed Rashel; Rahman, Md Musfikur; Amin, Ruhul; Karim, Md Rezaul; Mahmud, Zahid Hayat; Hossain, M Tofazzal

    2016-06-01

    Recently, a lectin was purified from the potato cultivated in Bangladesh locally known as Sheel. In the present study cytotoxicity of the lectin against Ehrlich ascites carcinoma (EAC) cells was studied by MTT assay in vitro in RPMI-1640 medium and 8.0-36.0 % cell growth inhibition was observed at the range of 2.5-160 μg/ml protein concentration when incubated for 24 h. The lectin-induced apoptosis in EAC cells was confirmed by fluorescence and optical microscope. The apoptotic cell death was also confirmed by using caspase inhibitors. Cells growth inhibition caused by the lectin (36 %) was remarkably decreased to 7.6 and 22.3 % respectively in the presence of caspase-3 and -8 inhibitors. RT-PCR was used to evaluate the expression of apoptosis-related genes Bcl-X, p53, and Bax. An intensive expression of Bcl-X gene was observed in untreated control EAC cells with the disappeared of the gene in Sheel-treated EAC cells. At the same time, Bax gene expression appeared only in Sheel-treated EAC cells and the expression level of the p53 gene was increased remarkable after the treatment of EAC cells with the lectin. The lectin showed strong agglutination activity against EAC cells. Flow cytometry was used to study the cell cycle phases of EAC cells and it was observed that the lectin arrested the G2/M phase. In conclusion, Sheel lectin inhibited EAC cells growth by inducing apoptosis.

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

    SciTech Connect

    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.

  3. Fresh Garlic Extract Induces Growth Arrest and Morphological Differentiation of MCF7 Breast Cancer Cells

    PubMed Central

    DiCarlo, Stephen E.; Reddy, Thipparthi R.

    2012-01-01

    Consumption of diets rich in fruits and vegetables is often associated with a reduced risk of developing cancer, particularly breast cancer. Considering that 1 in 8 women in the United States will develop breast cancer in the course of her lifetime, dietary manipulation could have a major impact on the incidence of breast cancer. We report here that fresh extracts of garlic (not boiled) arrested the growth and altered the morphology of MCF7 breast cancer cells. Deregulated levels of E-cadherin, cytokeratin8/18, and β-catenin correlated with the altered phenotype. We propose that early down-regulation of cyclin D1, reduced phosphorylation of ERK1, and increased phosphorylation of eIF2-α triggered the phenotypical changes. Reduced expression of hsp27 and sam68 and elevated levels of Rb and p21 further contributed to the sustained growth reduction. These findings provide a better understanding of the cellular responses to dietary supplements and provide potential options to treat breast cancer. PMID:23050048

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

    PubMed

    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

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

    PubMed Central

    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

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

    PubMed

    Wang, Wenmeng; Luo, Junqing; Xiang, Fang; Liu, Xueting; Jiang, Manli; Liao, Lingjuan; Hu, Jinyue

    2014-01-01

    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. PMID:25290311

  7. The production of reactive oxygen species and the mitochondrial membrane potential are modulated during onion oil-induced cell cycle arrest and apoptosis in A549 cells.

    PubMed

    Wu, Xin-jiang; Stahl, Thorsten; Hu, Ying; Kassie, Fekadu; Mersch-Sundermann, Volker

    2006-03-01

    Protective effects of Allium vegetables against cancers have been shown extensively in experimental animals and epidemiologic studies. We investigated cell proliferation and the induction of apoptosis by onion oil extracted from Allium cepa, a widely consumed Allium vegetable, in human lung cancer A549 cells. GC/MS analysis suggested that propyl sulfides but not allyl sulfides are major sulfur-containing constituents of onion oil. Onion oil at 12.5 mg/L significantly induced apoptosis (13% increase of apoptotic cells) as indicated by sub-G1 DNA content. It also caused cell cycle arrest at the G2/M phase; 25 mg/L onion oil increased the percentage of G2/M cells almost 6-fold compared with the dimethyl sulfoxide control. The action of onion oil may occur via a reactive oxygen species-dependent pathway because cell cycle arrest and apoptosis were blocked by the antioxidants N-acetylcysteine and exogenous glutathione. Marked collapse of the mitochondrial membrane potential suggested that dysfunction of the mitochondria may be involved in the oxidative burst and apoptosis induced by onion oil. Expression of phospho-cdc2 and phospho-cyclin B1 were downregulated by onion oil, perhaps accounting for the G2/M arrest. Overall, these results suggest that onion oil may exert chemopreventive action by inducing cell cycle arrest and apoptosis in tumor cells.

  8. Inhibitory effect of isoamericanol A from Jatropha curcas seeds on the growth of MCF-7 human breast cancer cell line by G2/M cell cycle arrest.

    PubMed

    Katagi, Ayako; Sui, Li; Kamitori, Kazuyo; Suzuki, Toshisada; Katayama, Takeshi; Hossain, Akram; Noguchi, Chisato; Dong, Youyi; Yamaguchi, Fuminori; Tokuda, Masaaki

    2016-01-01

    Although various parts of J. curcas (Jatropha curcas L., Euphorbiaceae) have long been used as traditional folk medicines for their antiviral, analgesic, and/or antidotal efficacies, we are the first to investigate the role of anti-carcinogenicity of isoamericanol A (IAA) from the seed extract. Our results showed that IAA is capable of inhibiting cell proliferation in a dose-dependent manner on the human cancer cell lines of MCF-7, MDA-MB231, HuH-7, and HeLa. Flow cytometry analysis showed IAA significantly induces cell cycle arrest at G2/M on MCF-7 cells. At both protein and mRNA levels examined by western blot and real-time PCR, the results revealed increased expression of BTG2 (B-cell translocation gene 2), p21 (p21(WAF1/CIPI) ), and GADD45A (growth arrest and DNA-damage-inducible, alpha) after IAA treatment, but inversed expression in CDK1 (cyclin-dependent kinase 1) and cyclins B1 and B2. All these effects contribute to G2/M cell cycle arrest. Furthermore, these results coincide with the changes in molecular expressions determined by DNA-microarray analysis. Our findings indicate that IAA has an inhibitory effect on cell proliferation of MCF-7 through cell cycle arrest, giving it great potential as a future therapeutic reagent for cancers. PMID:27441238

  9. H4 Histamine Receptors Mediate Cell Cycle Arrest in Growth Factor-Induced Murine and Human Hematopoietic Progenitor Cells

    PubMed Central

    Petit-Bertron, Anne-France; Machavoine, François; Defresne, Marie Paule; Gillard, Michel; Chatelain, Pierre; Mistry, Prakash

    2009-01-01

    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. PMID:19662098

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

    PubMed

    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

  11. Luteolin induces cell cycle arrest and apoptosis through extrinsic and intrinsic signaling pathways in MCF-7 breast cancer cells.

    PubMed

    Park, Su-Ho; Ham, Sunyoung; Kwon, Tae Ho; Kim, Man Sub; Lee, Dong Hun; Kang, Jeoung-Woo; Oh, Sei-Ryang; Yoon, Do-Young

    2014-01-01

    Luteolin is a common flavonoid that exists in medicinal herbs, fruits, and vegetables. Luteolin has biochemical functions including anti-allergy, anti-inflammation, and anti-cancer functions. However, its efficacy and precise mode of action against breast cancer are still under study. To elucidate whether luteolin exhibits an anticancer effect in breast cancer, MCF-7 breast cancer cells were incubated with luteolin, and apoptosis was assessed by observing nuclear morphological changes and by performing cell viability assay, cell cycle analysis, annexin V-FITC/PI double staining, western blotting, RT-PCR, and mitochondrial membrane potential measurements. Luteolin inhibited growth through perturbation of cell cycle progression at the sub-G1 and G1 phases in MCF-7 cells. Furthermore, luteolin enhanced the expression of death receptors, such as DR5, and activated caspase cascades. It enhanced the activities of caspase-8/-9/-3 in a dose-dependent manner, followed by inactivation of PARP. Activation of caspase-8 and caspase-9 induced caspase-3 activity, respectively, in apoptosis of extrinsic and intrinsic pathways. Luteolin also induced mitochondrial membrane potential collapse and cytochrome c release, and increased Bax expression by inhibiting expression of Bcl-2. Taken together, these results suggest that luteolin provokes cell cycle arrest and induces apoptosis by activating the extrinsic and intrinsic pathways. PMID:25272060

  12. Neferine, an alkaloid from lotus seed embryo, inhibits human lung cancer cell growth by MAPK activation and cell cycle arrest.

    PubMed

    Poornima, Paramasivan; Weng, Ching Feng; Padma, Viswanadha Vijaya

    2014-01-01

    Neferine is the major bisbenzylisoquinoline alkaloid isolated from the seed embryo of a traditional medicinal plant Nelumbo nucifera (Lotus). Epidemiological studies have revealed the therapeutic potential of lotus seed embryo. Although several mechanisms have been proposed, a clear anticancer action mechanism of neferine on lung cancer cells is still not known. Lung cancer is the most common cause of cancer death in the world, and the patients with advanced stage of nonsmall lung cancer require adjunct chemotherapy after surgical resection for the eradication of cancer cells. In this study, the effects of neferine were evaluated and characterized in A549 cells. Neferine induced apoptosis in a dose-dependent manner with the hypergeneration of reactive oxygen species, activation of MAPKs, lipid peroxidation, depletion of cellular antioxidant pool, loss of mitochondrial membrane potential, and intracellular calcium accumulation. Furthermore, neferine treatment leads to the inhibition of nuclear factor kappaB and Bcl2, upregulation of Bax and Bad, release of cytochrome C, activation of caspase cascade, and DNA fragmentation. In addition, neferine could induce p53 and its effector protein p21 and downregulation of cell cycle regulatory protein cyclin D1 thereby inducing G1 cell cycle arrest. These results suggest a novel function of neferine as an apoptosis inducer in lung cancer cells.

  13. A novel platinum compound inhibits constitutive Stat3 signaling and induces cell cycle arrest and apoptosis of malignant cells.

    PubMed

    Turkson, James; Zhang, Shumin; Mora, Linda B; Burns, Audrey; Sebti, Said; Jove, Richard

    2005-09-23

    Previous studies have established constitutive activation of Stat3 protein as one of the molecular changes required for tumorigenesis. To develop novel therapeutics for tumors harboring constitutively active Stat3, compounds from the NCI 2000 diversity set were evaluated for inhibition of Stat3 DNA-binding activity in vitro. Of these, a novel platinum (IV) compound, IS3 295, interacted with Stat3 and inhibited its binding to specific DNA-response elements. Further analysis suggested noncompetitive-type kinetics for the inhibition of Stat3 binding to DNA. In human and mouse tumor cell lines with constitutively active Stat3, IS3 295 selectively attenuated Stat3 signaling, thereby inducing cell growth arrest at G0/G1 phase and apoptosis. Moreover, in transformed cells, IS3 295 repressed expression of cyclin D1 and bcl-xL, two of the known Stat3-regulated genes that are overexpressed in malignant cells, suggesting that IS3 295 mediates anti-tumor cell activity in part by blocking Stat3-mediated sub-version of cell growth and apoptotic signals. Together, our findings provide evidence for the inhibition of Stat3 activity and biological functions by IS3 295 through interaction with Stat3 protein. This study represents a significant advance in small molecule-based approaches to target Stat3 and suggests potential new applications for platinum (IV) complexes as modulators of the Stat3 pathway for cancer therapy.

  14. Deoxyinosine triphosphate induces MLH1/PMS2- and p53-dependent cell growth arrest and DNA instability in mammalian cells.

    PubMed

    Yoneshima, Yasuto; Abolhassani, Nona; Iyama, Teruaki; Sakumi, Kunihiko; Shiomi, Naoko; Mori, Masahiko; Shiomi, Tadahiro; Noda, Tetsuo; Tsuchimoto, Daisuke; Nakabeppu, Yusaku

    2016-01-01

    Deoxyinosine (dI) occurs in DNA either by oxidative deamination of a previously incorporated deoxyadenosine residue or by misincorporation of deoxyinosine triphosphate (dITP) from the nucleotide pool during replication. To exclude dITP from the pool, mammals possess specific hydrolysing enzymes, such as inosine triphosphatase (ITPA). Previous studies have shown that deficiency in ITPA results in cell growth suppression and DNA instability. To explore the mechanisms of these phenotypes, we analysed ITPA-deficient human and mouse cells. We found that both growth suppression and accumulation of single-strand breaks in nuclear DNA of ITPA-deficient cells depended on MLH1/PMS2. The cell growth suppression of ITPA-deficient cells also depended on p53, but not on MPG, ENDOV or MSH2. ITPA deficiency significantly increased the levels of p53 protein and p21 mRNA/protein, a well-known target of p53, in an MLH1-dependent manner. Furthermore, MLH1 may also contribute to cell growth arrest by increasing the basal level of p53 activity. PMID:27618981

  15. Deoxyinosine triphosphate induces MLH1/PMS2- and p53-dependent cell growth arrest and DNA instability in mammalian cells

    PubMed Central

    Yoneshima, Yasuto; Abolhassani, Nona; Iyama, Teruaki; Sakumi, Kunihiko; Shiomi, Naoko; Mori, Masahiko; Shiomi, Tadahiro; Noda, Tetsuo; Tsuchimoto, Daisuke; Nakabeppu, Yusaku

    2016-01-01

    Deoxyinosine (dI) occurs in DNA either by oxidative deamination of a previously incorporated deoxyadenosine residue or by misincorporation of deoxyinosine triphosphate (dITP) from the nucleotide pool during replication. To exclude dITP from the pool, mammals possess specific hydrolysing enzymes, such as inosine triphosphatase (ITPA). Previous studies have shown that deficiency in ITPA results in cell growth suppression and DNA instability. To explore the mechanisms of these phenotypes, we analysed ITPA-deficient human and mouse cells. We found that both growth suppression and accumulation of single-strand breaks in nuclear DNA of ITPA-deficient cells depended on MLH1/PMS2. The cell growth suppression of ITPA-deficient cells also depended on p53, but not on MPG, ENDOV or MSH2. ITPA deficiency significantly increased the levels of p53 protein and p21 mRNA/protein, a well-known target of p53, in an MLH1-dependent manner. Furthermore, MLH1 may also contribute to cell growth arrest by increasing the basal level of p53 activity. PMID:27618981

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

    PubMed

    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.

  17. Celecoxib, a COX-2 Selective Inhibitor, Induces Cell Cycle Arrest at the G2/M Phase in HeLa Cervical Cancer Cells.

    PubMed

    Setiawati, Agustina; Setiawati, Agustina

    2016-01-01

    Celecoxib, a selective inhibitor of COX-2, showed cytotoxic effects in many cancer cell lines including cervical cancer cells. This study investigated the effect of celecoxib on cell cycle arrest in HeLa cervical cancer cells through p53 expression. In vitro anticancer activity was determined with the 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) method. A double staining method was applied to investigate the mechanism of cell death, cell cycling was analyzed by flow cytometryand immunocytochemistry was employed to stain p53 expression in cells. Celecoxib showed strong cytotoxic effects and induced apoptosis with an IC50 value of 40 μM. It induced cell cycle arrest at G2/M phase by increasing level of p53 expression on HeLa cells. PMID:27221835

  18. The p53 co-activator Zac1 neither induces cell cycle arrest nor apoptosis in chicken Lim1 horizontal progenitor cells

    PubMed Central

    Fard, S Shirazi; Blixt, MKE; Hallböök, F

    2015-01-01

    Chicken horizontal progenitor cells are able to enter their final mitosis even in the presence of DNA damage despite having a functional p53-p21 system. This suggests that they are resistant to DNA damage and that the regulation of the final cell cycle of horizontal progenitor cells is independent of the p53-p21 system. The activity of p53 is regulated by positive and negative modulators, including the zinc finger containing transcription factor Zac1 (zinc finger protein that regulates apoptosis and cell cycle arrest). Zac1 interacts with and enhances the activity of p53, thereby inducing cell cycle arrest and apoptosis. In this work, we use a gain-of-function assay in which mouse Zac1 (mZac1) is overexpressed in chicken retinal progenitor cells to study the effect on the final cell cycle of horizontal progenitor cells. The results showed that overexpression of mZac1 induced expression of p21 in a p53-dependent way and arrested the cell cycle as well as triggered apoptosis in chicken non-horizontal retinal progenitor cells. The negative regulation of the cell cycle by mZac1 is consistent with its proposed role as a tumour-suppressor gene. However, the horizontal cells were not affected by mZac1 overexpression. They progressed into S- and late G2/M-phase despite overexpression of mZac1. The inability of mZac1 to arrest the cell cycle in horizontal progenitor cells support the notion that the horizontal cells are less sensitive to events that triggers the p53 system during their terminal and neurogenic cell cycle, compared with other retinal cells. These properties are associated with a cell that has a propensity to become neoplastic and thus with a cell that may develop retinoblastoma. PMID:27551456

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

    SciTech Connect

    Suzuki, Masatoshi; Yamauchi, Motohiro; Oka, Yasuyoshi; Suzuki, Keiji; Yamashita, Shunichi

    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.

  20. Acetate Supplementation Induces Growth Arrest of NG2/PDGFRα-Positive Oligodendroglioma-Derived Tumor-Initiating Cells

    PubMed Central

    Long, Patrick M.; Tighe, Scott W.; Driscoll, Heather E.; Moffett, John R.; Namboodiri, Aryan M. A.; Viapiano, Mariano S.; Lawler, Sean E.; Jaworski, Diane M.

    2013-01-01

    Cancer is associated with globally hypoacetylated chromatin and considerable attention has recently been focused on epigenetic therapies. N-acetyl-L-aspartate (NAA), the primary storage form of acetate in the brain, and aspartoacylase (ASPA), the enzyme responsible for NAA catalysis to generate acetate and ultimately acetyl-Coenzyme A for histone acetylation, are reduced in oligodendroglioma. The short chain triglyceride glyceryl triacetate (GTA), which increases histone acetylation and inhibits histone deacetylase expression, has been safely used for acetate supplementation in Canavan disease, a leukodystrophy due to ASPA mutation. We demonstrate that GTA induces cytostatic G0 growth arrest of oligodendroglioma-derived cells in vitro, without affecting normal cells. Sodium acetate, at doses comparable to that generated by complete GTA catalysis, but not glycerol also promoted growth arrest, whereas long chain triglycerides promoted cell growth. To begin to elucidate its mechanism of action, the effects of GTA on ASPA and acetyl-CoA synthetase protein levels and differentiation of established human oligodendroglioma cells (HOG and Hs683) and primary tumor-derived oligodendroglioma cells that exhibit some features of cancer stem cells (grade II OG33 and grade III OG35) relative to an oligodendrocyte progenitor line (Oli-Neu) were examined. The nuclear localization of ASPA and acetyl-CoA synthetase-1 in untreated cells was regulated during the cell cycle. GTA-mediated growth arrest was not associated with apoptosis or differentiation, but increased expression of acetylated proteins. Thus, GTA-mediated acetate supplementation may provide a safe, novel epigenetic therapy to reduce the growth of oligodendroglioma cells without affecting normal neural stem or oligodendrocyte progenitor cell proliferation or differentiation. PMID:24278309

  1. Selective cell cycle arrest and induction of apoptosis in human prostate cancer cells by a polyphenol-rich extract of Solanum nigrum.

    PubMed

    Nawab, Akbar; Thakur, Vijay S; Yunus, Mohammad; Ali Mahdi, Abbas; Gupta, Sanjay

    2012-02-01

    Progression of prostate cancer is associated with escape of tumor cells from cell cycle arrest and apoptosis. Agents capable of selectively eliminating cancer cells by cell cycle arrest and/or induction of apoptosis offer a highly desirable approach. Here we demonstrate that a polyphenolic extract derived from ripe berries of Solanum nigrum (SN) differentially causes cell cycle arrest and apoptosis in various human prostate cancer cells without affecting normal prostate epithelial cells. Virally transformed normal human prostate epithelial PZ-HPV-7 cells and their cancer counterpart CA-HPV-10 cells, were used to evaluate the growth-inhibitory effects of the SN extract. SN treatment (5-20 µg/ml) of PZ-HPV-7 cells resulted in growth inhibitory responses of low magnitude. In sharp contrast, SN treatment of CA-HPV-10 cells increased cytotoxicity, decreased cell viability and induced apoptosis. Similar results were noted in the human prostate cancer LNCaP, 22Rv1, DU145 and PC-3 cell lines, where significant reductions in cell viability and induction of apoptosis was observed in all these cells, an effect independent of disease stage and androgen association. Cell cycle analysis revealed that SN treatment (5-20 µg/ml) resulted in a dose-dependent G2/M phase arrest and subG1 accumulation in the CA-HPV-10 but not in the PZ-HPV-7 cell line. Our results, for the first time, demonstrate that the SN extract is capable of selectively inhibiting cellular proliferation and accelerating apoptotic events in prostate cancer cells. SN may be developed as a promising therapeutic and/or preventive agent against prostate cancer. PMID:22076244

  2. Selective cell cycle arrest and induction of apoptosis in human prostate cancer cells by a polyphenol-rich extract of Solanum nigrum

    PubMed Central

    NAWAB, AKBAR; THAKUR, VIJAY S.; YUNUS, MOHAMMAD; MAHDI, ABBAS ALI; GUPTA, SANJAY

    2012-01-01

    Progression of prostate cancer is associated with escape of tumor cells from cell cycle arrest and apoptosis. Agents capable of selectively eliminating cancer cells by cell cycle arrest and/or induction of apoptosis offer a highly desirable approach. Here we demonstrate that a polyphenolic extract derived from ripe berries of Solanum nigrum (SN) differentially causes cell cycle arrest and apoptosis in various human prostate cancer cells without affecting normal prostate epithelial cells. Virally transformed normal human prostate epithelial PZ-HPV-7 cells and their cancer counterpart CA-HPV-10 cells, were used to evaluate the growth-inhibitory effects of the SN extract. SN treatment (5–20 μg/ml) of PZ-HPV-7 cells resulted in growth inhibitory responses of low magnitude. In sharp contrast, SN treatment of CA-HPV-10 cells increased cytotoxicity, decreased cell viability and induced apoptosis. Similar results were noted in the human prostate cancer LNCaP, 22Rv1, DU145 and PC-3 cell lines, where significant reductions in cell viability and induction of apoptosis was observed in all these cells, an effect independent of disease stage and androgen association. Cell cycle analysis revealed that SN treatment (5–20 μg/ml) resulted in a dose-dependent G2/M phase arrest and subG1 accumulation in the CA-HPV-10 but not in the PZ-HPV-7 cell line. Our results, for the first time, demonstrate that the SN extract is capable of selectively inhibiting cellular proliferation and accelerating apoptotic events in prostate cancer cells. SN may be developed as a promising therapeutic and/or preventive agent against prostate cancer. PMID:22076244

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

    PubMed Central

    Hsiao, Yung-Hsuan; Lin, Ching-I; Liao, Hsiang; Chen, Yue-Hua; Lin, Shyh-Hsiang

    2014-01-01

    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. PMID:25402647

  4. Tetrandrine induces G1/S cell cycle arrest through the ROS/Akt pathway in EOMA cells and inhibits angiogenesis in vivo.

    PubMed

    Xiao, Wenkai; Jiang, Yajie; Men, Qiuxu; Yuan, Ling; Huang, Zebo; Liu, Ting; Li, Wenhua; Liu, Xin

    2015-01-01

    Tetrandrine, a bisbenzylisoquinoline alkaloid, is known to inhibit tumor cell proliferation and induce apoptosis in cancer models in vitro and in vivo. In the present study, tetrandrine significantly inhibited the proliferation of mouse endothelial cells (EOMA cell) and induced G1/S arrest in EOMA cells, in which the expressions of cyclin D and cyclin E and CDKs were downregulated. Tetrandrine treatment also caused intracellular accumulation of reactive oxygen species (ROS). Pretreatment with NAC, which is a ROS inhibitor, blocked G1/S cell arrest and cyclin regulation induced by tetrandrine, implying that ROS generation plays an important role in tetrandrine-induced cell cycle arrest. Furthermore, a decreased phospho-Akt protein level after tetrandrine treatment was reversible with the removal of the intracellular ROS by NAC. Notably, overexpression of Akt decreased tetrandrine-induced G1/S arrest. Finally, we verified the antiangiogenic effects of tetrandrine in vivo in a liver cancer xenograft model in nude mice. In conclusion, tetrandrine inhibits EOMA cell growth through the ROS/Akt pathway, and it could be a promising compound for cancer therapy as an inhibitor of tumor vascular growth. PMID:25355542

  5. Nobiletin, a Polymethoxylated Flavone, Inhibits Glioma Cell Growth and Migration via Arresting Cell Cycle and Suppressing MAPK and Akt Pathways.

    PubMed

    Lien, Li-Ming; Wang, Meng-Jiy; Chen, Ray-Jade; Chiu, Hou-Chang; Wu, Jia-Lun; Shen, Ming-Yi; Chou, Duen-Suey; Sheu, Joen-Rong; Lin, Kuan-Hung; Lu, Wan-Jung

    2016-02-01

    Nobiletin, a bioactive polymethoxylated flavone (5,6,7,8,3(') ,4(') -hexamethoxyflavone), is abundant in citrus fruit peel. Although nobiletin exhibits antitumor activity against various cancer cells, the effect of nobiletin on glioma cells remains unclear. The aim of this study was to determine the effects of nobiletin on the human U87 and Hs683 glioma cell lines. Treating glioma cells with nobiletin (20-100 µm) reduced cell viability and arrested the cell cycle in the G0/G1 phase, as detected using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and propidium iodide (PI) staining, respectively; however, nobiletin did not induce cell apoptosis according to PI-annexin V double staining. Data from western blotting showed that nobiletin significantly attenuated the expression of cyclin D1, cyclin-dependent kinase 2, cyclin-dependent kinase 4, and E2 promoter-binding factor 1 (E2F1) and the phosphorylation of Akt/protein kinase B and mitogen-activated protein kinases, including p38, extracellular signal-regulated kinase, and c-Jun N-terminal kinase. Our data also showed that nobiletin inhibited glioma cell migration, as detected by both functional wound healing and transwell migration assays. Altogether, the present results suggest that nobiletin inhibits mitogen-activated protein kinase and Akt/protein kinase B pathways and downregulates positive regulators of the cell cycle, leading to subsequent suppression of glioma cell proliferation and migration. Our findings evidence that nobiletin may have potential for treating glioblastoma multiforme.

  6. 5-demethyltangeretin inhibits human non-small cell lung cancer cell growth by inducing G2/M cell cycle arrest and apoptosis

    PubMed Central

    Charoensinphon, Noppawat; Qiu, Peiju; Dong, Ping; Zheng, Jinkai; Ngauv, Pearline; Cao, Yong; Li, Shiming; Ho, Chi-Tang; Xiao, Hang

    2013-01-01

    Scope Tangeretin and 5-demethyltangeretin (5DT) are two closely related polymethoxyflavones found in citrus fruits. We investigated growth inhibitory effects on three human non-small cell lung cancer (NSCLC) cells. Methods and results Cell viability assay demonstrated that 5DT inhibited NSCLC cell growth in a time- and dose-dependent manner, and IC50s of 5DT were 79-fold, 57-fold and 56-fold lower than those of tangeretin in A549, H460, and H1299 cells, respectively. Flow cytometry analysis showed that 5DT induced extensive G2/M cell cycle arrest and apoptosis in NSCLC cells, while tangeretin at 10-fold higher concentrations did not. The apoptosis induced by 5DT was further confirmed by activation of caspase-3 and cleavage of PARP. Moreover, 5DT dose-dependently upregulated p53 and p21Cip1/Waf1, and downregulated Cdc-2 (Cdk-1) and cyclin B1. HPLC analysis revealed that the intracellular levels of 5DT in NSCLC cells were 2.7 - 4.9-fold higher than those of tangeretin after the cells were treated with 5DT or tangeretin at the same concentration. Conclusions our results demonstrated that 5DT inhibited NSCLC cell growth by inducing G2/M cell cycle arrest and apoptosis. These effects were much stronger than those produced by tangeretin, which is partially due to the higher intracellular uptake of 5DT than tangeretin. PMID:23926120

  7. Inhibiting the anaphase promoting complex/cyclosome induces a metaphase arrest and cell death in multiple myeloma cells

    PubMed Central

    Lub, Susanne; Maes, Anke; Maes, Ken; De Veirman, Kim; De Bruyne, Elke; Menu, Eline; Fostier, Karel; Kassambara, Alboukadel; Moreaux, Jérôme; Hose, Dirk; Leleu, Xavier; King, Randall W.

    2016-01-01

    The anaphase promoting complex/cyclosome (APC/C) is an ubiquitin ligase involved in cell cycle. During the metaphase-anaphase transition the APC/C is activated by Cdc20. The aim of this study is to elucidate the importance and therapeutic potential of APC/C and its co-activator Cdc20 in multiple myeloma (MM). Gene expression analysis revealed that Cdc20 was expressed at higher levels in gene expression-based high-risk MM patients. Moreover, high Cdc20 expression correlated with poor prognosis. Treatment of human myeloma cell lines with proTAME, an APC/C inhibitor, resulted in an accumulation of APC/CCdc20 substrate cyclin B1 and an accumulation of cells in metaphase. Moreover we observed a significant dose-dependent decrease in viability and increase in apoptosis in MM cells upon proTAME treatment. The induction of apoptosis was accompanied with caspase 3, 8, 9 and PARP cleavage. A similar metaphase arrest and induction of apoptosis were obtained with specific knockdown of Cdc20. In addition, we demonstrated the accumulation of Bim was partially responsible for the observed cell death. Combining proTAME with another APC/C inhibitor apcin or the alkylating agent melphalan resulted in enhanced anti-MM activity. This study suggests that the APC/C and its co-activator Cdc20 could be a new and promising target especially in high-risk MM patients. PMID:26716651

  8. c-Myc is a novel target of cell cycle arrest by honokiol in prostate cancer cells.

    PubMed

    Hahm, Eun-Ryeong; Singh, Krishna Beer; Singh, Shivendra V

    2016-09-01

    Honokiol (HNK), a highly promising phytochemical derived from Magnolia officinalis plant, exhibits in vitro and in vivo anticancer activity against prostate cancer but the underlying mechanism is not fully clear. This study was undertaken to delineate the role of c-Myc in anticancer effects of HNK. Exposure of prostate cancer cells to plasma achievable doses of HNK resulted in a marked decrease in levels of total and/or phosphorylated c-Myc protein as well as its mRNA expression. We also observed suppression of c-Myc protein in PC-3 xenografts upon oral HNK administration. Stable overexpression of c-Myc in PC-3 and 22Rv1 cells conferred significant protection against HNK-mediated growth inhibition and G0-G1 phase cell cycle arrest. HNK treatment decreased expression of c-Myc downstream targets including Cyclin D1 and Enhancer of Zeste Homolog 2 (EZH2), and these effects were partially restored upon c-Myc overexpression. In addition, PC-3 and DU145 cells with stable knockdown of EZH2 were relatively more sensitive to growth inhibition by HNK compared with control cells. Finally, androgen receptor overexpression abrogated HNK-mediated downregulation of c-Myc and its targets particularly EZH2. The present study indicates that c-Myc, which is often overexpressed in early and late stages of human prostate cancer, is a novel target of prostate cancer growth inhibition by HNK.

  9. High fat diet triggers cell cycle arrest and excessive apoptosis of granulosa cells during the follicular development.

    PubMed

    Wu, Yanqing; Zhang, Zhenghong; Liao, Xinghui; Wang, Zhengchao

    2015-10-23

    The regulatory mechanism of granulosa cells (GCs) proliferation during the follicular development is complicated and multifactorial, which is essential for the oocyte growth and normal ovarian functions. To investigate the role of high fat diet (HFD) on the proliferation of GCs, 4-week old female mice were fed with HFD or normal control diet (NC) for 15 weeks or 20 weeks and then detected the expression level of some regulatory molecules of cell cycle and apoptosis. The abnormal ovarian morphology was observed at 20 weeks. Further mechanistic studies indicated that HFD induced-obesity caused elevated apoptotic levels in GCs of the ovaries in a time-dependent manner. Moreover, cell cycle progress was also impacted after HFD fed. The cell cycle inhibitors, p27(Kip1) and p21(Cip1), were significantly induced in the ovaries from the mice in HFD group when compared with that in the ovaries from the mice in NC group. Subsequently, the expression levels of Cyclin D1, D3 and CDK4 were also significantly influenced in the ovaries from the mice fed with HFD in a time-dependent manner. The present results suggested that HFD induced-obesity may trigger cell cycle arrest and excessive apoptosis of GCs, causing the abnormal follicular development and ovarian function failure.

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

    PubMed Central

    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. PMID:27313685

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

    PubMed Central

    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

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

    PubMed

    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

  13. Protein kinase CK2 is involved in G2 arrest and apoptosis following spindle damage in epithelial cells.

    PubMed

    Sayed, M; Pelech, S; Wong, C; Marotta, A; Salh, B

    2001-10-25

    p53 undergoes phosphorylation on several residues in response to cellular stresses that include UV and ionizing radiation, however the influence of spindle damage on this parameter is relatively unclear. Consequently, the effect of nocodazole on serine 392 phosphorylation was examined in two epithelial cell lines. We show that this process is dependent upon the stepwise activation of p38 mitogen-activated protein kinase (p38 MAPK) and protein kinase casein kinase 2 (CK2). Furthermore, this activation correlated with the biochemical regulation of the maturation-promoting factor (MPF, cdc2/cyclin B), as both DRB and antisense depletion of CK2, as well as SB203580 were associated with an inhibition of its activation in response to nocodazole. Strikingly, when the cell cycle characteristics of nocodazole treated cells were examined, we observed that depletion or inhibition of the catalytic subunit of CK2, in the presence of microtubule inhibitors, resulted in a compromise of the G2 arrest (spindle checkpoint). Furthermore, CK2-depleted, nocodazole treated cells demonstrated a dramatic reduction in the apoptotic cell fraction, confirming that these cells had been endowed with oncogenic properties. These changes were observed in both HeLa cells and HCT116 cells. We also show that this effect is dependent on the presence of functional wild-type p53, as this phenomenon is not apparent in HCT116 p53(-/-) cells. Collectively, our results indicate two novel roles for CK2 in the spindle checkpoint arrest, in concert with p53. Firstly, to maintain increased cyclinB/cdc2 kinase activity, as a component of G2 arrest, and secondly, a role in p53-mediated apoptosis. These findings may have implications for an improved understanding of abnormalities of the spindle checkpoint in human cancers, which is a prerequisite for defining future therapies. PMID:11704824

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

    SciTech Connect

    Kim, Ju-Hwa; Yoo, Hye-In; Kang, Han Sung; Ro, Jungsil; Yoon, Sungpil

    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.

  15. Cell cycle arrest by prostaglandin A1 at the G1/S phase interface with up-regulation of oncogenes in S-49 cyc- cells

    NASA Technical Reports Server (NTRS)

    Hughes-Fulford, M.

    1994-01-01

    Our previous studies have implied that prostaglandins inhibit cell growth independent of cAMP. Recent reports, however, have suggested that prostaglandin arrest of the cell cycle may be mediated through protein kinase A. In this report, in order to eliminate the role of c-AMP in prostaglandin mediated cell cycle arrest, we use the -49 lymphoma variant (cyc-) cells that lack adenylate cyclase activity. We demonstrate that dimethyl prostaglandin A1 (dmPGA1) inhibits DNA synthesis and cell growth in cyc- cells. DNA synthesis is inhibited 42% by dmPGA1 (50 microM) despite the fact that this cell line lacks cellular components needed for cAMP generation. The ability to decrease DNA synthesis depends upon the specific prostaglandin structure with the most effective form possessing the alpha, beta unsaturated ketone ring. Dimethyl PGA1 is most effective in inhibiting DNA synthesis in cyc- cells, with prostaglandins PGE1 and PGB1 being less potent inhibitors of DNA synthesis. DmPGE2 caused a significant stimulation of DNA synthesis. S-49 cyc- variant cells exposed to (30-50 microns) dmPGA1, arrested in the G1 phase of the cell cycle within 24 h. This growth arrest was reversed when the prostaglandin was removed from the cultured cells; growth resumed within hours showing that this treatment is not toxic. The S-49 cyc- cells were chosen not only for their lack of adenylate cyclase activity, but also because their cell cycle has been extensively studied and time requirements for G1, S, G2, and M phases are known. Within hours after prostaglandin removal the cells resume active DNA synthesis, and cell number doubles within 15 h suggesting rapid entry into S-phase DNA synthesis from the G1 cell cycle block.(ABSTRACT TRUNCATED AT 250 WORDS).

  16. Herp depletion arrests the S phase of the cell cycle and increases estradiol synthesis in mouse granulosa cells.

    PubMed

    Chen, Fenglei; Wang, Nan; Yang, Diqi; Wen, Xin; Mahmoud, Tagwa Norain; Zhou, Dong; Tang, Keqiong; Lin, Pengfei; Wang, Aihua; Jin, Yaping

    2016-04-22

    The endoplasmic reticulum (ER) stress response has been implicated in the development, atresia and luteinization of ovarian follicles. However, there have been few reports concerning the role of Herp, an ER stress-induced protein, in follicular development. The present study aims to detect the distribution and cyclic variations of Herp during the estrous cycle and to reveal the roles of Herp in regulating the cell cycle, apoptosis and steroid hormone biosynthesis in mouse granulosa cells. In this study, immunohistochemistry staining showed that Herp expression was primarily in the granulosa cells and oocytes. Furthermore, we constructed recombinant lentiviral vectors for Herp short hairpin interfering RNA (shRNA) expression; immunofluorescence staining, real-time quantitative PCR (RT-qPCR) and western blot analysis revealed that Herp was successfully knocked down. Flow cytometry showed that knockdown of Herp arrested granulosa cells at the S phase of the cell cycle. More importantly, ELISA analysis revealed that Herp knockdown significantly upregulated the concentration of estradiol (E2) in the culture supernatants. RT-qPCR was performed to determine the regulatory mechanism of Herp knockdown in the cell cycle, and in steroid synthesis, RT-qPCR analysis revealed that Herp knockdown upregulated the mRNA expression of steroidogenic enzymes (Cyp19a1) and downregulated metabolic enzymes (Cyp1b1) and cell cycle factors (cyclin A1, cyclin B1 and cyclin D2). These results suggest that Herp may regulate the cell cycle and hormone secretions in mouse granulosa cells. The present study helps to elucidate the physiological functions of Herp as they relate to reproduction. PMID:26781490

  17. Cell growth inhibition, G2/M cell cycle arrest, and apoptosis induced by chloroquine in human breast cancer cell line Bcap-37.

    PubMed

    Jiang, Pei-du; Zhao, Ying-lan; Shi, Wei; Deng, Xiao-qiang; Xie, Gang; Mao, Yong-qiu; Li, Zheng-guang; Zheng, Yu-zhu; Yang, Sheng-yong; Wei, Yu-quan

    2008-01-01

    Chloroquine is an antimalarial drug that has been used in the treatment and prophylaxis of malaria since the 1950s. The present study was undertaken to examine the effects of chloroquine on Bcap-37 human breast cancer cells' growth, cell cycle modulation, apoptosis induction, and associated molecular alterations in vitro. The chloroquine treatment decreased the viability of Bcap-37 cells in a concentration- and time-dependent manner, which correlated with G(2)/M phase cell cycle arrest. The chloroquine-mediated cell cycle arrest was associated with a decrease in protein levels/activity of polo-like kinase 1 (Plk1), phosphorylated cell division cycle 25C (Cdc25C), phosphorylated extracellular signal-regulated kinase 1/2 (ERK1/2), phosphorylated Akt. The chloroquine-treated Bcap-37 cells exhibited a marked decrease in the level of mitochondrial transmembrane potential (DeltaPsim), which was accompanied by the activation of caspase-3 and cleaved poly(ADP-ribose) polymerase (PARP). Exposure of Bcap-37 cells to chloroquine also resulted in the induction of spindle abnormalities. In conclusion, the findings in this study suggested that chloroquine might have potential anticancer efficacy, which could be attributed, in part, to its proliferation inhibition and apoptosis induction of cancer cells through modulation of apoptosis and cell cycle-related proteins expressions, down-regulation of mitochondrial transmembrane potential (DeltaPsim), and induction of spindle abnormalities. PMID:19088425

  18. Sodium butyrate regulates androgen receptor expression and cell cycle arrest in human prostate cancer cells.

    PubMed

    Kim, Jeonga; Park, Hyeyoung; Im, Ji Young; Choi, Wahn Soo; Kim, Hyung Sik

    2007-01-01

    Histone deacetylase (HDAC) inhibitors have been shown to modify the expression of a variety of genes related to cell cycle regulation and apoptosis in several cancer cells. However, the precise mode of action of HDAC inhibitors in prostate cancer cells is not completely understood. This study examined whether an HDAC inhibitor affects cell death in human prostate cancer cells through the epigenetic regulation of androgen receptor (AR) expression. The molecular mechanism of the HDAC inhibitor, sodium butyrate, on the epigenetic alterations of cell cycle regulators was evaluated in androgen-dependent human prostate cancer LNCaP cells. The expression levels of acetylated histone H3 and H4 increased significantly after 48 h treatment with sodium butyrate. Sodium butyrate induced the expression of AR after 48 h treatment. In addition, immunofluorescence assay revealed the nuclear localization of the AR after sodium butyrate treatment. Sodium butyrate also significantly decreased the expression of the cell cycle regulatory proteins (cyclin D1/cyclin dependent kinase (CDK)4, CDK6, and cyclin E/CDK2) in the LNCaP cells after 48 h treatment. Furthermore, p21Waf1/Cip1 and p27Kip1 were upregulated as a result of the sodium butyrate treatment. These results suggest that sodium butyrate effectively inhibited cell proliferation and induced apoptosis of human prostate cancer cells by altering the expression of cell cycle regulators and AR. This study indicated that sodium butyrate may be a potential agent in prostate cancer treatment.

  19. Existence, Functional Impairment, and Lung Repair Potential of Endothelial Colony-Forming Cells in Oxygen-Induced Arrested Alveolar Growth

    PubMed Central

    Alphonse, Rajesh S.; Vadivel, Arul; Fung, Moses; Shelley, William Chris; Critser, Paul John; Ionescu, Lavinia; O’Reilly, Megan; Ohls, Robin K.; McConaghy, Suzanne; Eaton, Farah; Zhong, Shumei; Yoder, Merv; Thébaud, Bernard

    2014-01-01

    Background Bronchopulmonary dysplasia and emphysema are life-threatening diseases resulting from impaired alveolar development or alveolar destruction. Both conditions lack effective therapies. Angiogenic growth factors promote alveolar growth and contribute to alveolar maintenance. Endothelial colony-forming cells (ECFCs) represent a subset of circulating and resident endothelial cells capable of self-renewal and de novo vessel formation. We hypothesized that resident ECFCs exist in the developing lung, that they are impaired during arrested alveolar growth in experimental bronchopulmonary dysplasia, and that exogenous ECFCs restore disrupted alveolar growth. Methods and Results Human fetal and neonatal rat lungs contain ECFCs with robust proliferative potential, secondary colony formation on replating, and de novo blood vessel formation in vivo when transplanted into immunodeficient mice. In contrast, human fetal lung ECFCs exposed to hyperoxia in vitro and neonatal rat ECFCs isolated from hyperoxic alveolar growth–arrested rat lungs mimicking bronchopulmonary dysplasia proliferated less, showed decreased clonogenic capacity, and formed fewer capillary-like networks. Intrajugular administration of human cord blood–derived ECFCs after established arrested alveolar growth restored lung function, alveolar and lung vascular growth, and attenuated pulmonary hypertension. Lung ECFC colony- and capillary-like network-forming capabilities were also restored. Low ECFC engraftment and the protective effect of cell-free ECFC-derived conditioned media suggest a paracrine effect. Long-term (10 months) assessment of ECFC therapy showed no adverse effects with persistent improvement in lung structure, exercise capacity, and pulmonary hypertension. Conclusions Impaired ECFC function may contribute to arrested alveolar growth. Cord blood–derived ECFC therapy may offer new therapeutic options for lung diseases characterized by alveolar damage. PMID:24710033

  20. Mitochondrial ribosomal protein L41 mediates serum starvation-induced cell-cycle arrest through an increase of p21{sup WAF1/CIP1}

    SciTech Connect

    Kim, Mi Jin; Yoo, Young A.; Kim, Hyung Jung; Kang, Seongman; Kim, Yong Geon; Kim, Jun Suk; Yoo, Young Do . E-mail: ydy1130@korea.ac.kr

    2005-12-16

    Ribosomal proteins not only act as components of the translation apparatus but also regulate cell proliferation and apoptosis. A previous study reported that MRPL41 plays an important role in p53-dependent apoptosis. It also showed that MRPL41 arrests the cell cycle by stabilizing p27{sup Kip1} in the absence of p53. This study found that MRPL41 mediates the p21{sup WAF1/CIP1}-mediated G1 arrest in response to serum starvation. The cells were released from serum starvation-induced G1 arrest via the siRNA-mediated blocking of MRPL41 expression. Overall, these results suggest that MRPL41 arrests the cell cycle by increasing the p21{sup WAF1/CIP1} and p27{sup Kip1} levels under the growth inhibitory conditions.

  1. Phenethyl Isothiocyanate (PEITC) Inhibits the Growth of Human Oral Squamous Carcinoma HSC-3 Cells through G0/G1 Phase Arrest and Mitochondria-Mediated Apoptotic Cell Death

    PubMed Central

    Chen, Po-Yuan; Lin, Kai-Chun; Lin, Jing-Pin; Tang, Nou-Ying; Yang, Jai-Sing; Lu, Kung-Wen; Chung, Jing-Gung

    2012-01-01

    Phenethyl isothiocyanate (PEITC), an effective anticancer and chemopreventive agent, has been reported to inhibit cancer cell growth through cell-cycle arrest and induction of apoptotic events in various human cancer cells models. However, whether PEITC inhibits human oral squamous cell carcinoma HSC-3 cell growth and its underlying mechanisms is still not well elucidated. In the present study, we evaluated the inhibitory effects of PEITC in HSC-3 cells and examined PEITC-modulated cell-cycle arrest and apoptosis. The contrast-phase and flow cytometric assays were used for examining cell morphological changes and viability, respectively. The changes of cell-cycle and apoptosis-associated protein levels were determined utilizing Western blotting in HSC-3 cells after exposure to PEITC. Our results indicated that PEITC effectively inhibited the HSC-3 cells' growth and caused apoptosis. PEITC induced G0/G1 phase arrest through the effects of associated protein such as p53, p21, p17, CDK2 and cyclin E, and it triggered apoptosis through promotion of Bax and Bid expression and reduction of Bcl-2, leading to decrease the levels of mitochondrial membrane potential (ΔΨm), and followed the releases of cytochrome c, AIF and Endo G then for causing apoptosis in HSC-3 cells. These results suggest that PEITC could be an antitumor compound for oral cancer therapy. PMID:22919418

  2. Downregulation of HDAC9 inhibits cell proliferation and tumor formation by inducing cell cycle arrest in retinoblastoma.

    PubMed

    Zhang, Yiting; Wu, Dan; Xia, Fengjie; Xian, Hongyu; Zhu, Xinyue; Cui, Hongjuan; Huang, Zhenping

    2016-04-29

    Histone deacetylase 9 (HDAC9) is a member of class II HDACs, which regulates a wide variety of normal and abnormal physiological functions. Recently, HDAC9 has been found to be overexpressed in some types of human cancers. However, the role of HDAC9 in retinoblastoma remains unclear. In this study, we found that HDAC9 was commonly expressed in retinoblastoma tissues and HDAC9 was overexpressed in prognostically poor retinoblastoma patients. Through knocking down HDAC9 in Y79 and WERI-Rb-1 cells, the expression level of HDAC9 was found to be positively related to cell proliferation in vitro. Further investigation indicated that knockdown HDAC9 could significantly induce cell cycle arrest at G1 phase in retinoblastoma cells. Western blot assay showed downregulation of HDAC9 could significantly decrease cyclin E2 and CDK2 expression. Lastly, xenograft study in nude mice showed that downregulation of HDAC9 inhibited tumor growth and development in vivo. Therefore, our results suggest that HDAC9 could serve as a novel potential therapeutic target in the treatment of retinoblastoma. PMID:27033599

  3. Histological lesions, cell cycle arrest, apoptosis and T cell subsets changes of spleen in chicken fed aflatoxin-contaminated corn.

    PubMed

    Peng, Xi; Zhang, Keying; Bai, Shiping; Ding, Xuemei; Zeng, Qiufeng; Yang, Jun; Fang, Jing; Chen, Kejie

    2014-08-20

    The purpose of this study was to evaluate the effects of corn naturally contaminated with aflatoxin B1 and aflatoxin B2 on pathological lesions, apoptosis, cell cycle phases and T lymphocyte subsets of spleen, and to provide an experimental basis for understanding the mechanism of aflatoxin-induced immunosuppression. A total of 900 COBB500 male broilers were randomly allocated into five groups with six replicates per group and 30 birds per replicate. The experiment lasted for 6 weeks and the five dietary treatments consisted of control, 25% contaminated corn, 50% contaminated corn, 75% contaminated corn and 100% contaminated corn groups. The histopathological spleen lesions from the contaminated corn groups was characterized as congestion of red pulp, increased necrotic cells and vacuoles in the splenic corpuscle and periarterial lymphatic sheath. The contaminated corn intake significantly increased relative weight of spleen, percentages of apoptotic splenocytes, induced cell cycle arrest of splenocytes, increased the percentages of CD3+CD8+ T cells and decreased the ratios of CD3+CD4+ to CD3+CD8+. The results suggest that AFB-induced immunosuppression maybe closely related to the lesions of spleen.

  4. Iso-suillin from the mushroom Suillus flavus induces cell cycle arrest and apoptosis in K562 cell line.

    PubMed

    Wang, Ying; Zhang, Qingshuang; Zhao, Junxia; Zhao, Xiaojing; Zhang, Jinxiu; Wang, Li-an

    2014-05-01

    Iso-suillin, an isomer of suillin that belongs to the prenylphenol class of fungal derivatives, was isolated from petroleum ether extracts of Suillus flavus. The IC50 value of iso-suillin in K562 cells was 0.87 μM, which was lower than the positive control cisplatin (19.33 μM). Iso-suillin-treated K562 cells exhibited an increased rate of apoptosis, mitochondrial membrane potential (MMP) depolarization, and G0/G1 arrest. Western blot analysis revealed that these cells displayed significantly upregulated expression of several apoptosis-related proteins, including cytochrome c, caspase 9, FADD (Fas-associating protein with a novel death domain), caspase 8, caspase 3, and Bax. Moreover, the expression of two anti-apoptosis proteins, NF-κB and Bcl-2, was downregulated. Inhibitors of caspase 9 and caspase 8 protected the K562 cells from apoptosis. Taken together, our results suggest that iso-suillin induces K562 apoptosis through the mitochondrial and death receptor pathways and that iso-suillin may represent a candidate anti-leukemia treatment.

  5. Lupiwighteone induces cell cycle arrest and apoptosis and activates the Nrf2/ARE pathway in human neuroblastoma cells.

    PubMed

    Ren, Jie; Yang, Jie; Xu, Yuanyuan; Huang, Qianhui; Yang, Meng; Hu, Kun

    2015-02-01

    Lupiwighteone (Lup) is a kind of natural isoflavone, but its pharmacological effect and active mechanism are rarely reported. This study aimed to investigate the anticancer and cancer preventive effects of Lup on human neuroblastoma (SH-SY5Y) cells. We found that Lup could inhibit SH-SY5Y cells growth in a concentration- and time-dependent manner. Further studies suggested that Lup could induce G2/M phase arrest associated with an evident decrease in cyclin B1/D1 and cyclin dependent kinase (CDK) 1/2/4/6 protein expressions. Moreover, Lup could regulate the changes of mitochondrial membrane potential and increase intracellular reactive oxygen species (ROS) production. After the cells were treated with Lup, topical morphological characteristics were observed; apoptosis-related protein expressions, such as Bax, cytochrome c, cleaved caspase-9, cleaved caspase-3 and cleaved PARP-1 were increased; and protein expressions, such as Bcl-2, procaspase-9, PARP-1 and P-Akt were decreased. These changes were observed simultaneously. In addition, Nrf2 transcription factor activation was detected by an ARE-GFP reporter assay. Nrf2 nuclear localization was then investigated using a fluorescence microscope. Furthermore, Nrf2 and Keap1 protein levels were determined by western blot. Our results may provide a scientific basis for the application of the anticancer and cancer preventive effects of Lup on SH-SY5Y cells.

  6. Transcriptional profiling of breast cancer cells in response to mevinolin: Evidence of cell cycle arrest, DNA degradation and apoptosis.

    PubMed

    Mahmoud, Ali M; Aboul-Soud, Mourad A M; Han, Junkyu; Al-Sheikh, Yazeed A; Al-Abd, Ahmed M; El-Shemy, Hany A

    2016-05-01

    The merging of high-throughput gene expression techniques, such as microarray, in the screening of natural products as anticancer agents, is considered the optimal solution for gaining a better understanding of the intervention mechanism. Red yeast rice (RYR), a Chinese dietary product, contains a mixture of hypocholesterolemia agents such as statins. Typically, statins have this effect via the inhibition of HMG‑CoA reductase, the key enzyme in the biosynthesis of cholesterol. Recently, statins have been shown to exhibit various beneficial antineoplastic properties through the disruption of tumor angiogenesis and metastatic processes. Mevinolin (MVN) is a member of statins and is abundantly present in RYR. Early experimental trials suggested that the mixed apoptotic/necrotic cell death pathway is activated in response to MVN exposure. In the current study, the cytotoxic profile of MVN was evaluated against MCF‑7, a breast cancer‑derived cell line. The obtained results indicated that MVN‑induced cytotoxicity is multi‑factorial involving several regulatory pathways in the cytotoxic effects of MVN on breast cancer cell lines. In addition, MVN‑induced transcript abundance profiles inferred from microarrays showed significant changes in some key cell processes. The changes were predicted to induce cell cycle arrest and reactive oxygen species generation but inhibit DNA repair and cell proliferation. This MVN‑mediated multi‑factorial stress triggered specific programmed cell death (apoptosis) and DNA degradation responses in breast cancer cells. Taken together, the observed MVN‑induced effects underscore the potential of this ubiquitous natural compound as a selective anticancer activity, with broad safety margins and low cost compared to benchmarked traditional synthetic chemotherapeutic agents. Additionally, the data support further pre‑clinical and clinical evaluations of MVN as a novel strategy to combat breast cancer and overcome drug resistance

  7. Transcriptional profiling of breast cancer cells in response to mevinolin: Evidence of cell cycle arrest, DNA degradation and apoptosis

    PubMed Central

    MAHMOUD, ALI M.; ABOUL-SOUD, MOURAD A.M.; HAN, JUNKYU; AL-SHEIKH, YAZEED A.; AL-ABD, AHMED M.; EL-SHEMY, HANY A.

    2016-01-01

    The merging of high-throughput gene expression techniques, such as microarray, in the screening of natural products as anticancer agents, is considered the optimal solution for gaining a better understanding of the intervention mechanism. Red yeast rice (RYR), a Chinese dietary product, contains a mixture of hypocholesterolemia agents such as statins. Typically, statins have this effect via the inhibition of HMG-CoA reductase, the key enzyme in the biosynthesis of cholesterol. Recently, statins have been shown to exhibit various beneficial antineoplastic properties through the disruption of tumor angiogenesis and metastatic processes. Mevinolin (MVN) is a member of statins and is abundantly present in RYR. Early experimental trials suggested that the mixed apoptotic/necrotic cell death pathway is activated in response to MVN exposure. In the current study, the cytotoxic profile of MVN was evaluated against MCF-7, a breast cancer-derived cell line. The obtained results indicated that MVN-induced cytotoxicity is multi-factorial involving several regulatory pathways in the cytotoxic effects of MVN on breast cancer cell lines. In addition, MVN-induced transcript abundance profiles inferred from microarrays showed significant changes in some key cell processes. The changes were predicted to induce cell cycle arrest and reactive oxygen species generation but inhibit DNA repair and cell proliferation. This MVN-mediated multi-factorial stress triggered specific programmed cell death (apoptosis) and DNA degradation responses in breast cancer cells. Taken together, the observed MVN-induced effects underscore the potential of this ubiquitous natural compound as a selective anticancer activity, with broad safety margins and low cost compared to benchmarked traditional synthetic chemotherapeutic agents. Additionally, the data support further pre-clinical and clinical evaluations of MVN as a novel strategy to combat breast cancer and overcome drug resistance. PMID:26983896

  8. δ-Cadinene inhibits the growth of ovarian cancer cells via caspase-dependent apoptosis and cell cycle arrest.

    PubMed

    Hui, Li-Mei; Zhao, Guo-Dong; Zhao, Jian-Jun

    2015-01-01

    Ovarian cancer is one of the most common causes of mortality among all cancers in females and is the primary cause of mortality from gynecological malignancies. The objective of the current research work was to evaluate a naturally occurring sesquiterpene-δ-Cadinene for its antiproliferative and apoptotic effects on human ovary cancer (OVCAR-3) cells. We also demonstrated the effect of δ-Cadinene on cell cycle phase distribution, intracellular damage and caspase activation. Sulforhodamine B (SRB) assay was used to evaluate the antiproliferative effect of δ-cadinene on OVCAR-3 cells. Cellular morphology after δ-cadinene treatment was demonstrated by inverted phase contrast microscopy, fluorescence microscopy and transmission electron microscopy. Flow cytometry was used to analyze the effect of δ-cadinene on cell cycle phase distribution and apoptosis using propidium iodide and Annexin V-fluorescein isothiocyanate (FITC)/PI kit. The results revealed that δ-cadinene induced dose-dependent as well as time-dependent growth inhibitory effects on OVACR-3 cell line. δ-cadinene also induced cell shrinkage, chromatin condensation and nuclear membrane rupture which are characteristic of apoptosis. Treatment with different doses of δ-cadinene also led to cell cycle arrest in sub-G1 phase which showed dose-dependence. Western blotting assay revealed that δ-cadinene led to activation of caspases in OVCAR-3 cancer cells. PARP cleavage was noticed at 50 µM dose of δ-cadinene with the advent of the cleaved 85-kDa fragment after exposure to δ-cadinene. At 100 µM, only the cleaved form of PARP was detectable. Pro-caspase-8 expression remained unaltered until 10 µM dose of δ-cadinene. However, at 50 and 100 µM dose, pro-caspase-8 expression was no longer detectable. There was a significant increase in the caspase-9 expression levels after 50 and 100 µM δ-cadinene treatments.

  9. Comparative hybrid arrest by tandem antisense oligodeoxyribonucleotides or oligodeoxyribonucleoside methylphosphonates in a cell-free system.

    PubMed Central

    Maher, L J; Dolnick, B J

    1988-01-01

    Antisense oligonucleotides containing either anionic diester or neutral methylphosphonate internucleoside linkages were prepared by automated synthesis, and were compared for their ability to arrest translation of human dihydrofolate reductase (DHFR) mRNA in a nuclease treated rabbit reticulocyte lysate. In the case of oligodeoxyribonucleotides, tandem targeting of three 14-mers resulted in synergistic and complete selective inhibition of DHFR synthesis at a total oligomer concentration of 25 microM. Hybrid arrest by three or six tandem oligodeoxyribonucleoside methylphosphonates was dramatically less effective. This difference does not result from preferential recognition of hybrids involving oligodeoxyribonucleotides by endogenous RNaseH activity. A ribonuclease protection assay demonstrated that antisense oligodeoxyribonucleoside methylphosphonates bind selectively to target RNA sequences, but with 275 fold lower affinity than the corresponding oligodeoxyribonucleotides. This low binding affinity results in poor arrest of translation, and may be related to the stereochemistry of the methylphosphonate linkage. Images PMID:2836793

  10. PF-04691502 triggers cell cycle arrest, apoptosis and inhibits the angiogenesis in hepatocellular carcinoma cells.

    PubMed

    Wang, Feng-Ze; Peng-Jiao; Yang, Na-Na; Chuang-Yuan; Zhao, Ya-Li; Liu, Qiang-Qiang; Fei, Hong-Rong; Zhang, Ji-Guo

    2013-07-01

    Hepatocellular carcinoma (HCC) is a major cause of morbidity and mortality in the world. The aim of the present study is to determine the antitumor effect of PF-04691502, a potent inhibitor of PI3K and mTOR kinases, on the apoptosis and angiogenesis of the hepatoma cancer cells. Our results indicate that treatment of cancer cells with PF-04691502 reduces cell viability and inhibits cell growth in a dose-dependent manner. PF-04691502 triggers apoptosis via a mitochondrial pathway, accompanied by activation of caspase-3, caspase-9, and poly(ADP-ribose) polymerase (PARP). Pre-treatment of hepatoma cells with the caspase-3 inhibitor (z-DEVD-fmk) blocks the PF-04691502-induced death of these cells. In addition, growth factors-induced tube formation and the migration of HUVECs are markedly inhibited by PF-04691502 treatment. The mechanisms of anti-angiogenesis of PF-04691502 are associated with inhibiting the expression of VEGF and HIF-1α. Based on the overall results, we suggest that PF-04691502 reduces hepatocellular carcinoma cell viability, induces cell apoptosis, and inhibits cell growth and tumor angiogenesis, implicating its potential therapeutic value in the treatment of HCC.

  11. δ-tocotrienol induces human bladder cancer cell growth arrest, apoptosis and chemosensitization through inhibition of STAT3 pathway.

    PubMed

    Ye, Changxiao; Zhao, Wei; Li, Minghui; Zhuang, Junlong; Yan, Xiang; Lu, Qun; Chang, Cunjie; Huang, Xiaojing; Zhou, Ji; Xie, Bingxian; Zhang, Zhen; Yao, Xin; Yan, Jun; Guo, Hongqian

    2015-01-01

    Vitamin E intake has been implicated in reduction of bladder cancer risk. However, the mechanisms remain elusive. Here we reported that δ-tocotrienol (δ-T3), one of vitamin E isomers, possessed the most potent cytotoxic capacity against human bladder cancer cells, compared with other Vitamin E isomers. δ-T3 inhibited cancer cell proliferation and colonogenicity through induction of G1 phase arrest and apoptosis. Western blotting assay revealed that δ-T3 increased the expression levels of cell cycle inhibitors (p21, p27), pro-apoptotic protein (Bax) and suppressed expression levels of cell cycle protein (Cyclin D1), anti-apoptotic proteins (Bcl-2, Bcl-xL and Mcl-1), resulting in the Caspase-3 activation and cleavage of PARP. Moreover, the δ-T3 treatment inhibited ETK phosphorylation level and induced SHP-1 expression, which was correlated with downregulation of STAT3 activation. In line with this, δ-T3 reduced the STAT3 protein level in nuclear fraction, as well as its transcription activity. Knockdown of SHP-1 partially reversed δ-T3-induced cell growth arrest. Importantly, low dose of δ-T3 sensitized Gemcitabine-induced cytotoxic effects on human bladder cancer cells. Overall, our findings demonstrated, for the first time, the cytotoxic effects of δ-T3 on bladder cancer cells and suggest that δ-T3 might be a promising chemosensitization reagent for Gemcitabine in bladder cancer treatment. PMID:25849286

  12. PAI-1 Expression Is Required for HDACi-Induced Proliferative Arrest in ras-Transformed Renal Epithelial Cells

    PubMed Central

    Higgins, Stephen P.; Higgins, Craig E.; Higgins, Paul J.

    2011-01-01

    Malignant transformation of mammalian cells with ras family oncogenes results in dramatic changes in cellular architecture and growth traits. The generation of flat revertants of v-K-ras-transformed renal cells by exposure to the histone deacetylase inhibitor sodium butyrate (NaB) was previously found to be dependent on transcriptional activation of the PAI-1 (SERPINE1) gene (encoding the type-1 inhibitor of urokinase and tissue-type plasminogen activators). NaB-initiated PAI-1 expression preceded induced cell spreading and entry into G1 arrest. To assess the relevance of PAI-1 induction to growth arrest in this cell system more critically, two complementary approaches were used. The addition of a stable, long half-life, recombinant PAI-1 mutant to PAI-1-deficient v-K-ras-/c-Ha-ras-transformants or to PAI-1 functionally null, NaB-resistant, 4HH cells (engineered by antisense knockdown of PAI-1 mRNA transcripts) resulted in marked cytostasis in the absence of NaB. The transfection of ras-transformed cells with the Rc/CMVPAI expression construct, moreover, significantly elevated constitutive PAI-1 synthesis (10- to 20-fold) with a concomitant reduction in proliferative rate. These data suggest that high-level PAI-1 expression suppresses growth of chronic ras-oncogene transformed cells and is likely a major cytostatic effector of NaB exposure. PMID:21912547

  13. Asperlin induces G{sub 2}/M arrest through ROS generation and ATM pathway in human cervical carcinoma cells

    SciTech Connect

    He, Long; Nan, Mei-Hua; Oh, Hyun Cheol; Kim, Young Ho; Jang, Jae Hyuk; Erikson, Raymond Leo; Ahn, Jong Seog; Kim, Bo Yeon

    2011-06-10

    Highlights: {yields} A new anti-cancer effect of an antibiotics, asperlin, is exploited. {yields} Asperlin induced human cervical cancer cell apoptosis through ROS generation. {yields} Asperlin activated DNA-damage related ATM protein and cell cycle associated proteins. {yields} Asperlin could be developed as a new anti-cancer therapeutics. -- Abstract: We exploited the biological activity of an antibiotic agent asperlin isolated from Aspergillus nidulans against human cervical carcinoma cells. We found that asperlin dramatically increased reactive oxygen species (ROS) generation accompanied by a significant reduction in cell proliferation. Cleavage of caspase-3 and PARP and reduction of Bcl-2 could also be detected after asperlin treatment to the cells. An anti-oxidant N-acetyl-L-cysteine (NAC), however, blocked all the apoptotic effects of asperlin. The involvement of oxidative stress in asperlin induced apoptosis could be supported by the findings that ROS- and DNA damage-associated G2/M phase arrest and ATM phosphorylation were increased by asperlin. In addition, expression and phosphorylation of cell cycle proteins as well as G2/M phase arrest in response to asperlin were significantly blocked by NAC or an ATM inhibitor KU-55933 pretreatment. Collectively, our study proved for the first time that asperlin could be developed as a potential anti-cancer therapeutics through ROS generation in HeLa cells.

  14. Cell cycle arrest mediated by a pyridopyrimidine is not abrogated by over-expression of Bcl-2 and cyclin D1.

    PubMed

    Soni, R; Chaudhuri, B

    2001-05-01

    Inhibition of cyclin dependent kinases (Cdks) is of pivotal importance in tumor cell biology as these kinases are the drivers of cell proliferation. This inhibition can be achieved either by naturally occurring biological proteins or by small molecule compounds. They cause cell cycle arrest and/or apoptosis depending upon the specificity and efficacy of the inhibitor in question. We have reported earlier that specific pyridopyrimidines (novel Cdk inhibitors) cause cell cycle arrest in mink lung epithelial cells and the arrest is abrogated by over-expression of Cdk4. In contrast, we show here that one of these inhibitors effectively maintains cell cycle arrest in a leukemic or a breast cancer cell line even after the respective cells over-express an oncogene, either Bcl-2 or cyclin D1. However, in the leukemic cells, Bcl-2 over-expression suppresses apoptosis induced by the pyridopyrimidine. Thus, novel Cdk inhibitors can prove to be useful chemical genetics tools for understanding the underlying mechanisms of growth arrest and/or apoptosis in normal versus tumor cells. This could also lead to the development of improved inhibitors of cell proliferation.

  15. Ligand modulation of a dinuclear platinum compound leads to mechanistic differences in cell cycle progression and arrest

    PubMed Central

    Menon, Vijay R.; Peterson, Erica J.; Valerie, Kristoffer; Farrell, Nicholas P.; Povirk, Lawrence F.

    2013-01-01

    Despite similar structures and DNA binding profiles, two recently synthesized dinuclear platinum compounds are shown to elicit highly divergent effects on cell cycle progression. In colorectal HCT116 cells, BBR3610 shows a classical G2/M arrest with initial accumulation in S phase, but the derivative compound BBR3610-DACH, formed by introduction of the 1,2-diaminocyclohexane (DACH) as carrier ligand, results in severe G1/S as well as G2/M phase arrest, with nearly complete S phase depletion. The origin of this unique effect was studied. Cellular interstrand crosslinking as assayed by comet analysis was similar for both compounds, confirming previous in vitro results obtained on plasmid DNA. Immunoblotting revealed a stabilization of p53 and concomitant transient increases in p21 and p27 proteins after treatment with BBR3610-DACH. Cell viability assays and cytometric analysis of p53 and p21 null cells indicated that BBR3610-DACH-induced cell cycle arrest was p21-dependent and partially p53-dependent. However, an increase in the levels of cyclin E was observed with steady state levels of CDK2 and Cdc25A, suggesting that the G1 block occurs downstream of CDK/cyclin complex formation. The G2/M block was corroborated with decreased levels of cyclin A and cyclin B1. Surprisingly, BBR3610-DACH-induced G1 block was independent of ATM and ATR. Finally, both compounds induced apoptosis, with BBR3610-DACH showing a robust PARP-1 cleavage that was not associated with caspase-3/7 cleavage. In summary, BBR3610-DACH is a DNA binding platinum agent with unique inhibitory effects on cell cycle progression that could be further developed as a chemotherapeutic agent complementary to cisplatin and oxaliplatin. PMID:24161784

  16. N-Myristoyltransferase Inhibition Induces ER-Stress, Cell Cycle Arrest, and Apoptosis in Cancer Cells

    PubMed Central

    2016-01-01

    N-Myristoyltransferase (NMT) covalently attaches a C14 fatty acid to the N-terminal glycine of proteins and has been proposed as a therapeutic target in cancer. We have recently shown that selective NMT inhibition leads to dose-responsive loss of N-myristoylation on more than 100 protein targets in cells, and cytotoxicity in cancer cells. N-myristoylation lies upstream of multiple pro-proliferative and oncogenic pathways, but to date the complex substrate specificity of NMT has limited determination of which diseases are most likely to respond to a selective NMT inhibitor. We describe here the phenotype of NMT inhibition in HeLa cells and show that cells die through apoptosis following or concurrent with accumulation in the G1 phase. We used quantitative proteomics to map protein expression changes for more than 2700 proteins in response to treatment with an NMT inhibitor in HeLa cells and observed down-regulation of proteins involved in cell cycle regulation and up-regulation of proteins involved in the endoplasmic reticulum stress and unfolded protein response, with similar results in breast (MCF-7, MDA-MB-231) and colon (HCT116) cancer cell lines. This study describes the cellular response to NMT inhibition at the proteome level and provides a starting point for selective targeting of specific diseases with NMT inhibitors, potentially in combination with other targeted agents. PMID:27267252

  17. N-Myristoyltransferase Inhibition Induces ER-Stress, Cell Cycle Arrest, and Apoptosis in Cancer Cells.

    PubMed

    Thinon, Emmanuelle; Morales-Sanfrutos, Julia; Mann, David J; Tate, Edward W

    2016-08-19

    N-Myristoyltransferase (NMT) covalently attaches a C14 fatty acid to the N-terminal glycine of proteins and has been proposed as a therapeutic target in cancer. We have recently shown that selective NMT inhibition leads to dose-responsive loss of N-myristoylation on more than 100 protein targets in cells, and cytotoxicity in cancer cells. N-myristoylation lies upstream of multiple pro-proliferative and oncogenic pathways, but to date the complex substrate specificity of NMT has limited determination of which diseases are most likely to respond to a selective NMT inhibitor. We describe here the phenotype of NMT inhibition in HeLa cells and show that cells die through apoptosis following or concurrent with accumulation in the G1 phase. We used quantitative proteomics to map protein expression changes for more than 2700 proteins in response to treatment with an NMT inhibitor in HeLa cells and observed down-regulation of proteins involved in cell cycle regulation and up-regulation of proteins involved in the endoplasmic reticulum stress and unfolded protein response, with similar results in breast (MCF-7, MDA-MB-231) and colon (HCT116) cancer cell lines. This study describes the cellular response to NMT inhibition at the proteome level and provides a starting point for selective targeting of specific diseases with NMT inhibitors, potentially in combination with other targeted agents. PMID:27267252

  18. Comparison of ability of protein kinase C inhibitors to arrest cell growth and to alter cellular protein kinase C localisation.

    PubMed Central

    Courage, C.; Budworth, J.; Gescher, A.

    1995-01-01

    Inhibitors of protein kinase C (PKC) such as the staurosporine analogues UCN-01 and CGP 41251 possess antineoplastic properties, but the mechanism of their cytostatic action is not understood. We tested the hypothesis that the ability of these compounds to arrest growth is intrinsically linked with their propensity to inhibit PKC. Compounds with varying degrees of potency and specificity for PKC were investigated in A549 and MCF-7 carcinoma cells. When the log values of drug concentration which arrested cell growth by 50% (IC50) were plotted against the logs of the IC50 values for inhibition of cytosolic PKC activity, two groups of compound could be distinguished. The group which comprised the more potent inhibitors of enzyme activity (calphostin C, staurosporine and its analogues UCN-01, RO 31-8220, CGP 41251) were the stronger growth inhibitors, whereas the weaker enzyme inhibitors (trimethylsphingosine, miltefosine, NPC-15437, H-7, H-7I) affected proliferation less potently. GF 109203X was exceptional in that it inhibited PKC with an IC50 in the 10(-8) M range, yet was only weakly cytostatic. To substantiate the role of PKC in the growth inhibition caused by these agents, cells were depleted of PKC by incubation with bryostatin 1 (1 microM). The susceptibility of these enzyme-depleted cells towards growth arrest induced by staurosporine, RO 31-8220, UCN-01 or H-7 was studied. The drug concentrations which inhibited incorporation of [3H]thymidine into PKC-depleted A549 cells by 50% were slightly, but not significantly, lower than significantly, lower than those observed in control cells. These results suggest that PKC is unlikely to play a direct role in the arrest of the growth of A549 and MCF-7 cells mediated by these agents. Staurosporine is not only a strong inhibitor of PKC but also mimics activators of this enzyme in that it elicits the cellular redistribution of certain PKC isoenzymes. The ability of kinase inhibitors other than staurosporine to exert a

  19. Polynuclear platinum anticancer drugs are more potent than cisplatin and induce cell cycle arrest in glioma1

    PubMed Central

    Billecke, Christine; Finniss, Susan; Tahash, Laura; Miller, Cathie; Mikkelsen, Tom; Farrell, Nicholas P.; Bögler, Oliver

    2006-01-01

    We have evaluated the efficacy of the multinuclear platinum chemotherapeutics BBR3464, BBR3571, and BBR3610 against glioma cells in culture and animal models and investigated their mechanism of action at the cellular level. In a clonogenic assay, BBR3610, the most potent compound, had an IC90 dose (achieving 90% colony formation inhibition) that was 250 times lower than that of cisplatin for both LNZ308 and LN443 glioma cells. In subcutaneous xenografts of U87MG glioma cells, BBR3610 approximately doubled the time it took for a tumor to reach a predetermined size and significantly extended survival when these cells were implanted intracranially. Analysis of apoptosis and cell cycle distribution showed that BBR compounds induced G2/M arrest in the absence of cell death, while cisplatin predominantly induced apoptosis. Interestingly, the BBR compounds and cisplatin both induced extracellular signal-regulated kinase 1/2 phosphorylation, and inhibition of this pathway at the level of MEK antagonized the induction of G2/M arrest or apoptosis, respectively. Analysis of Chk1 and Chk2 status did not show any differential effects of the drugs, and it is thus unlikely to underlie the difference in response. Similarly, the drugs did not differentially modulate survivin levels, and knockdown of survivin did not convert the response to BBR3610 to apoptosis. Together, these findings support continued development of BBR3610 for clinical use against glioma and provide a framework for future investigation of mechanism of action. PMID:16723633

  20. Involvement of miR-15a in G0/G1 Phase Cell Cycle Arrest Induced by Porcine Circovirus Type 2 Replication.

    PubMed

    Quan, Rong; Wei, Li; Zhu, Shanshan; Wang, Jing; Cao, Yongchang; Xue, Chunyi; Yan, Xu; Liu, Jue

    2016-01-01

    Many viruses exploit the host cell division cycle to favour their own growth. Here we demonstrated that porcine circovirus type 2 (PCV2), which is a major causative agent of an emerging and important swine disease complex, PCV2-associated diseases, caused G0/G1 cell cycle arrest through degradation of cyclin D1 and E followed by reduction of retinoblastoma phosphorylation in synchronized PCV2-infected cells dependent upon virus replication. This induction of G0/G1 cell cycle arrest promoted PCV2 replication as evidenced by increased viral protein expression and progeny virus production in the synchronized PCV2-infected cells. To delineate a mechanism of miRNAs in regulating PCV2-induced G0/G1 cell cycle arrest, we determined expression levels of some relevant miRNAs and found that only miR-15a but not miR-16, miR-21, and miR-34a was significantly changed in the PCV2-infected cells. We further demonstrated that upregulation of miR-15a promoted PCV2-induced G0/G1 cell cycle arrest via mediating cyclins D1 and E degradation, in which involves PCV2 growth. These results reveal that G0/G1 cell cycle arrest induced by PCV2 may provide favourable conditions for viral protein expression and progeny production and that miR-15a is implicated in PCV2-induced cell cycle control, thereby contributing to efficient viral replication. PMID:27302568

  1. Involvement of miR-15a in G0/G1 Phase Cell Cycle Arrest Induced by Porcine Circovirus Type 2 Replication

    PubMed Central

    Quan, Rong; Wei, Li; Zhu, Shanshan; Wang, Jing; Cao, Yongchang; Xue, Chunyi; Yan, Xu; Liu, Jue

    2016-01-01

    Many viruses exploit the host cell division cycle to favour their own growth. Here we demonstrated that porcine circovirus type 2 (PCV2), which is a major causative agent of an emerging and important swine disease complex, PCV2-associated diseases, caused G0/G1 cell cycle arrest through degradation of cyclin D1 and E followed by reduction of retinoblastoma phosphorylation in synchronized PCV2-infected cells dependent upon virus replication. This induction of G0/G1 cell cycle arrest promoted PCV2 replication as evidenced by increased viral protein expression and progeny virus production in the synchronized PCV2-infected cells. To delineate a mechanism of miRNAs in regulating PCV2-induced G0/G1 cell cycle arrest, we determined expression levels of some relevant miRNAs and found that only miR-15a but not miR-16, miR-21, and miR-34a was significantly changed in the PCV2-infected cells. We further demonstrated that upregulation of miR-15a promoted PCV2-induced G0/G1 cell cycle arrest via mediating cyclins D1 and E degradation, in which involves PCV2 growth. These results reveal that G0/G1 cell cycle arrest induced by PCV2 may provide favourable conditions for viral protein expression and progeny production and that miR-15a is implicated in PCV2-induced cell cycle control, thereby contributing to efficient viral replication. PMID:27302568

  2. Cinnamic acid derivatives induce cell cycle arrest in carcinoma cell lines.

    PubMed

    Sova, Matej; Žižak, Željko; Stanković, Jelena A Antic; Prijatelj, Matevž; Turk, Samo; Juranić, Zorica D; Mlinarič-Raščan, Irena; Gobec, Stanislav

    2013-08-01

    Cinnamic acid derivatives can be found in plant material, and they possess a remarkable variety of biological effects. In the present study, we have investigated the cytotoxic effects of representative cinnamic acid esters and amides. The cytotoxicity was determined by MTT test on human cervix adenocarcinoma (HeLa), myelogenous leukemia (K562), malignant melanoma (Fem-x), and estrogen-receptor-positive breast cancer (MCF-7) cells, versus peripheral blood mononuclear cells (PBMCs) without or with the addition of the plant lectin phytohemaglutinin (PHA). The compounds tested showed significant cytotoxicity (IC50s between 42 and 166 µM) and furthermore selectivity of these cytotoxic effects on the malignant cell lines versus the PBMCs was also seen, especially when electron-withdrawing groups, such as a cyano group (compound 5), were present on the aromatic rings of the alcohol or amine parts of the cinnamic acid derivatives. The additional study on cell cycle phase distribution indicated that novel cinnamic acid derivatives inhibit cell growth by induction of cell death. Thus, cinnamic acids derivatives represent important lead compounds for further development of antineoplastic agents.

  3. Securinine from Phyllanthus glaucus Induces Cell Cycle Arrest and Apoptosis in Human Cervical Cancer HeLa Cells

    PubMed Central

    Krauze-Baranowska, Mirosława; Ochocka, J. Renata

    2016-01-01

    Background The Securinega-type alkaloids occur in plants belonging to Euphorbiaceae family. One of the most widely distributed alkaloid of this group is securinine, which was identified next to allosecurinine in Phyllanthus glaucus (leafflower). Recently, some Securinega-type alkaloids have paid attention to its antiproliferative potency towards different cancer cells. However, the cytotoxic properties of allosecurinine have not yet been evaluated. Methods The cytotoxicity of the extract, alkaloid fraction obtained from P. glaucus, isolated securinine and allosecurinine against HeLa cells was evaluated by real-time xCELLigence system and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Apoptosis was detected by annexin V and 7-amino-actinomycin (7-AAD) staining and confirmed with fluorescent Hoechst 33342 dye. The assessment of mitochondrial membrane potential (MMP), reactive oxygen species (ROS) generation, the level of extracellular signal-regulated protein kinases 1 and 2 (ERK1/2), caspase-3/7 activity and cell cycle analysis were measured by flow cytometry. The enzymatic activity of caspase-9 was assessed by a luminometric assay. The expression of apoptosis associated genes was analyzed by real-time PCR. Results The experimental data revealed that securinine and the alkaloid fraction were significantly potent on HeLa cells growth inhibition with IC50 values of 7.02 ± 0.52 μg/ml (32.3 μM) and 25.46 ± 1.79 μg/ml, respectively. The activity of allosecurinine and Phyllanthus extract were much lower. Furthermore, our study showed that the most active securinine induced apoptosis in a dose-dependent manner in the tested cells, increased the percentage of ROS positive cells and depolarized cells as well as stimulated the activity of ERK1/2, caspase-9 and -3/7. Securinine also induced cell cycle arrest in S phase. Real-time PCR analysis showed high expression of TNFRSF genes in the cells stimulated with securinine. Conclusions Securinine

  4. Cannabisin B induces autophagic cell death by inhibiting the AKT/mTOR pathway and S phase cell cycle arrest in HepG2 cells.

    PubMed

    Chen, Tianpeng; Hao, Jianxiong; He, Jinfeng; Zhang, Jianchun; Li, Yingcong; Liu, Rui; Li, Lite

    2013-06-01

    This study investigates the anticancer properties of cannabisin B, purified from hempseed hull, in HepG2 human hepatoblastoma cells. The results indicate that cannabisin B significantly inhibited cell proliferation by inducing autophagic cell death rather than typical apoptosis. Cell viability transiently increased upon the addition of a low concentration of cannabisin B but decreased upon the addition of high concentrations. Cannabisin B-induced changes in cell viability were completely inhibited by pre-treatment with 3-methyladenine (3-MA), indicating that the induction of autophagy by cannabisin B caused cell death. Additionally, cannabisin B induced S phase cell cycle arrest in a dose-dependent manner. Moreover, cannabisin B was found to inhibit survival signaling by blocking the activation of AKT and down-stream targets of the mammalian target of rapamycin (mTOR). These findings suggest that cannabisin B possesses considerable antiproliferative activity and that it may be utilised as a promising chemopreventive agent against hepatoblastoma disease.

  5. Loss of p53-mediated cell-cycle arrest, senescence and apoptosis promotes genomic instability and premature aging

    PubMed Central

    Li, Tongyuan; Liu, Xiangyu; Jiang, Le; Manfredi, James; Zha, Shan; Gu, Wei

    2016-01-01

    Although p53-mediated cell cycle arrest, senescence and apoptosis are well accepted as major tumor suppression mechanisms, the loss of these functions does not directly lead to tumorigenesis, suggesting that the precise roles of these canonical activities of p53 need to be redefined. Here, we report that the cells derived from the mutant mice expressing p533KR, an acetylation-defective mutant that fails to induce cell-cycle arrest, senescence and apoptosis, exhibit high levels of aneuploidy upon DNA damage. Moreover, the embryonic lethality caused by the deficiency of XRCC4, a key DNA double strand break repair factor, can be fully rescued in the p533KR/3KR background. Notably, despite high levels of genomic instability, p533KR/3KRXRCC4−/− mice, unlike p53−/− XRCC4−/− mice, are not succumbed to pro-B-cell lymphomas. Nevertheless, p533KR/3KR XRCC4−/− mice display aging-like phenotypes including testicular atrophy, kyphosis, and premature death. Further analyses demonstrate that SLC7A11 is downregulated and that p53-mediated ferroptosis is significantly induced in spleens and testis of p533KR/3KRXRCC4−/− mice. These results demonstrate that the direct role of p53-mediated cell cycle arrest, senescence and apoptosis is to control genomic stability in vivo. Our study not only validates the importance of ferroptosis in p53-mediated tumor suppression in vivo but also reveals that the combination of genomic instability and activation of ferroptosis may promote aging-associated phenotypes. PMID:26943586

  6. 5-(2-Carboxyethenyl) isatin derivative induces G{sub 2}/M cell cycle arrest and apoptosis in human leukemia K562 cells

    SciTech Connect

    Zhou, Yao; Zhao, Hong-Ye; Han, Kai-Lin; Yang, Yao; Song, Bin-Bin; Guo, Qian-Nan; Fan, Zhen-Chuan; Zhang, Yong-Min; Teng, Yu-Ou; Yu, Peng

    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.

  7. Activation of nuclear PTEN by inhibition of Notch signaling induces G2/M cell cycle arrest in gastric cancer.

    PubMed

    Kim, S-J; Lee, H-W; Baek, J-H; Cho, Y-H; Kang, H G; Jeong, J S; Song, J; Park, H-S; Chun, K-H

    2016-01-14

    Mutation in PTEN has not yet been detected, but its function as a tumor suppressor is inactivated in many cancers. In this study we determined that, activated Notch signaling disables PTEN by phosphorylation and thereby contributes to gastric tumorigenesis. Notch inhibition by small interfering RNA or γ-secretase inhibitor (GSI) induced mitotic arrest and apoptosis in gastric cancer cells. Notch inhibition induced dephosphorylation in the C-terminal domain of PTEN, which led to PTEN nuclear localization. Overexpression of activated Notch1-induced phosphorylation of PTEN and reversed GSI-induced mitotic arrest. Dephosphorylated nuclear PTEN caused prometaphase arrest by interaction with the cyclin B1-CDK1 complex, resulting in their accumulation in the nucleus and subsequent apoptosis. We found a correlation between high expression levels of Notch1 and low survival rates and, similarly, between reduced nuclear PTEN expression and increasing the TNM classification of malignant tumours stages in malignant tissues from gastric cancer patients. The growth of Notch1-depleted gastric tumors was significantly retarded in xenografted mice, and in addition, PTEN deletion restored growth similar to control tumors. We also demonstrated that combination treatment with GSI and chemotherapeutic agents significantly reduced the orthotopically transplanted gastric tumors in mice without noticeable toxicity. Overall, our findings suggest that inhibition of Notch signaling can be employed as a PTEN activator, making it a potential target for gastric cancer therapy.

  8. Cidan inhibits liver cancer cell growth by reducing COX-2 and VEGF expression and cell cycle arrest

    PubMed Central

    LI, NAN; ZHENG, DONGHAI; XUE, JIE; GUO, WEIXING; SHI, JIE; SUN, JUXIAN; LU, CHONGDE; ZHENG, WEIDA; WU, MENGCHAO; CHENG, SHUQUN

    2015-01-01

    treatment resulted in enhanced G1 and G2/M cell cycle arrest of CSQT-1 cells. Therefore, cidan effectively inhibited cell proliferation, reduced cell viability and downregulated COX-2 and VEGF expression levels in hepatoma cells. PMID:26136881

  9. Induced growth inhibition, cell cycle arrest and apoptosis in CD133+/CD44+ prostate cancer stem cells by flavopiridol

    PubMed Central

    SONER, BURAK CEM; AKTUG, HUSEYIN; ACIKGOZ, EDA; DUZAGAC, FAHRIYE; GUVEN, UMMU; AYLA, SULE; CAL, CAG; OKTEM, GULPERI

    2014-01-01

    Flavopiridol is a flavone that inhibits several cyclin-dependent kinases and exhibits potent growth-inhibitory activity, apoptosis and G1-phase arrest in a number of human tumor cell lines. Flavopiridol is currently undergoing investigation in human clinical trials. The present study focused on the effect of flavopiridol in cell proliferation, cell cycle progression and apoptosis in prostate cancer stem cells (CSCs). Therefore, cluster of differentiation 133 (CD133)+high/CD44+high prostate CSCs were isolated from the DU145 human prostate cancer cell line. The cells were treated with flavopiridol in a dose- and time-dependent manner to determine the inhibitory effect. Cell viability and proliferation were analyzed and the efficiency of flavopiridol was assessed using the sphere-forming assay. Flavopiridol was applied to monolayer cultures of CD133high/CD44high human prostate CSCs at the following final concentrations: 100, 300, 500 and 1000 nM. The cultures were incubated for 24, 48 and 72 h. The half maximal inhibitory concentration (IC50) value of the drug was determined as 500 nM for monolayer cells. Dead cells were analyzed prior and subsequent to exposure to increasing flavopiridol doses. Annexin-V and immunofluorescence analyses were performed for the evaluation of apoptotic pathways. According to the results, flavopiridol treatment caused significant growth inhibition at 500 and 1000 nM when compared to the control at 24 h. G0/G1 analysis showed a statistically significant difference between 100 and 500 nM (P<0.005), 100 and 1000 nM (P<0.001), 300 and 1000 nM (P<0.001), and 500 and 1000 nM (P<0.001). Flavopiridol also significantly influenced the cells in the G2/M phase, particularly at high-dose treatments. Flavopiridol induced growth inhibition and apoptosis at the IC50 dose (500 nM), resulting in a significant increase in immunofluorescence staining of caspase-3, caspase-8 and p53. In conclusion, the present results indicated that flavopiridol could be a

  10. Inhibition of cytokine-induced microvascular arrest of tumor cells by recombinant endostatin prevents experimental hepatic melanoma metastasis.

    PubMed

    Mendoza, Lorea; Valcárcel, María; Carrascal, Teresa; Egilegor, Eider; Salado, Clarisa; Sim, B Kim Lee; Vidal-Vanaclocha, Fernando

    2004-01-01

    We investigated effects of endostatin (ES) in the prometastatic microenvironment of inflammation occurring during the microvascular phase of cancer cell infiltration in the liver. We used a model of intrasplenic injection of B16 melanoma (B16M) cells leading to hepatic metastasis through vascular cell adhesion molecule-(VCAM-1)-mediated capillary arrest of cancer cells via interleukin-18 (IL-18)-dependent mechanism. We show that administration of 50 mg/kg recombinant human (rh) ES 30 min before B16M, plus repetition of same dose for 3 additional days decreased metastasis number by 60%. A single dose of rhES before B16M injection reduced hepatic microvascular retention of luciferase-transfected B16M by 40% and inhibited hepatic production of tumor necrosis factor alpha (TNF-alpha) and IL-18 and VCAM-1 expression by hepatic sinusoidal endothelia (HSE). Consistent with these data, rhES inhibited VCAM-1-dependent B16M cell adhesion to primary cultured HSE receiving B16M conditioned medium, and it abolished the HSE cell production of TNF-alpha and IL-18 induced by tumor-derived vascular endothelial cell growth factor (VEGF). rhES abrogated recombinant murine VEGF-induced tyrosine phosphorylation of KDR/flk-1 receptor in HSE cells, preventing the proinflammatory action of tumor-derived VEGF on HSE. rhES also abolished hepatic production of TNF-alpha, microvascular retention of luciferase-transfected B16M, and adhesion of B16M cells to isolated HSE cells, all of them induced in mice given 5 micro g/kg recombinant murine VEGF for 18 h. This capillary inflammation-deactivating capability constitutes a nonantiangiogenic antitumoral action of endostatin that decreases cancer cell arrest within liver microvasculature and prevents metastases promoted by proinflammatory cytokines induced by VEGF. PMID:14729638

  11. Inhibition of lung cancer cell growth by quercetin glucuronides via G2/M arrest and induction of apoptosis.

    PubMed

    Yang, Jen-Hung; Hsia, Te-Chun; Kuo, Hsiu-Maan; Chao, Pei-Dawn Lee; Chou, Chi-Chung; Wei, Yau-Huei; Chung, Jing-Gung

    2006-02-01

    Lung cancer is the leading cause of cancer death in many developed countries, including Taiwan. Quercetin, a widely distributed bioflavonoid, is well known to induce growth inhibition in a variety of human cancer cells. Quercetin glucuronides are the main circulating metabolites after dietary supplements with quercetin in humans. However, there is little information available as to how quercetin glucuronides affect human cancer cells. We investigated the effects of quercetin glucuronides in a human lung cancer cell line NCI-H209. We checked the cell viability, cell cycle checkpoint proteins, pro- and antiapoptotic proteins, caspase-3 activity, and gene expression by flow cytometry and Western blot. The viability of cells decreased in a dose- and time-dependent manner. Cell cycle analysis revealed a significant increase of the proportion of cells in G2/M phase and subG0/G1 phase (corresponding to apoptotic cells). Moreover, quercetin glucuronides increased the expressions of cyclin B, Cdc25c-ser-216-p, and Wee1 proteins, indicating the G2/M arrest. We also demonstrated a concurrent decrease of the mitochondrial membrane potential, release of cytochrome c, up-regulation of Bax, down-regulation of Bcl-2, and activation of caspase-3, and subsequently, cleavage of poly(ADP-ribose) polymerase. In addition, quercetin glucuronide-induced apoptosis was totally blocked by the broad-spectrum caspase inhibitor benzyloxycarbonyl-Val-Ala-Asp fluoromethylketone. Taken together, we demonstrated that quercetin glucuronides inhibited proliferation through G2/M arrest of the cell cycle and induced apoptosis via caspase-3 cascade in the human lung cancer cell line NCI-H209. Delineation of the biological effects of specific major quercetin metabolites on chemotherapeutic potential or chemoprevention of human cancers warrants further investigation. PMID:16280456

  12. Curcumin loaded PLGA-poloxamer blend nanoparticles induce cell cycle arrest in mesothelioma cells.

    PubMed

    Mayol, Laura; Serri, Carla; Menale, Ciro; Crispi, Stefania; Piccolo, Maria Teresa; Mita, Luigi; Giarra, Simona; Forte, Maurizio; Saija, Antonina; Biondi, Marco; Mita, Damiano Gustavo

    2015-06-01

    The pharmacological potential of curcumin (CURC) is severely restricted because of its low water solubility/absorption, short half-life and poor bioavailability. To overcome these issues, CURC-loaded nanoparticles (NPs) were produced by a double emulsion technique. In particular, NPs were made up of an amphiphilic blend of poloxamers and PLGA to confer stealth properties to the NPs to take advantage of the enhanced permeability and retention (EPR) effect. Different surface properties of NPs made up of bare PLGA and PLGA/poloxamer blend were confirmed by the different interactions of these NPs with serum proteins and also by their ability to be internalized by mesothelioma cell line. The uptake of PLGA/poloxamer NPs induces a persistent block in G0/G1 phase of the cell cycle up to 72 h, thus overcoming the drug tolerance phenomenon, normally evidenced with free CURC.

  13. Curcumin loaded PLGA-poloxamer blend nanoparticles induce cell cycle arrest in mesothelioma cells.

    PubMed

    Mayol, Laura; Serri, Carla; Menale, Ciro; Crispi, Stefania; Piccolo, Maria Teresa; Mita, Luigi; Giarra, Simona; Forte, Maurizio; Saija, Antonina; Biondi, Marco; Mita, Damiano Gustavo

    2015-06-01

    The pharmacological potential of curcumin (CURC) is severely restricted because of its low water solubility/absorption, short half-life and poor bioavailability. To overcome these issues, CURC-loaded nanoparticles (NPs) were produced by a double emulsion technique. In particular, NPs were made up of an amphiphilic blend of poloxamers and PLGA to confer stealth properties to the NPs to take advantage of the enhanced permeability and retention (EPR) effect. Different surface properties of NPs made up of bare PLGA and PLGA/poloxamer blend were confirmed by the different interactions of these NPs with serum proteins and also by their ability to be internalized by mesothelioma cell line. The uptake of PLGA/poloxamer NPs induces a persistent block in G0/G1 phase of the cell cycle up to 72 h, thus overcoming the drug tolerance phenomenon, normally evidenced with free CURC. PMID:25794477

  14. Romidepsin induces cell cycle arrest, apoptosis, histone hyperacetylation and reduces matrix metalloproteinases 2 and 9 expression in bortezomib sensitized non-small cell lung cancer cells.

    PubMed

    Karthik, Selvaraju; Sankar, Renu; Varunkumar, Krishnamoorthy; Ravikumar, Vilwanathan

    2014-04-01

    Histone deacetylase (HDAC) inhibitors have been proven to be effective therapeutic agents to kill cancer cells through inhibiting HDAC activity or altering the structure of chromatin. We recently reported that chemotherapy by the HDAC inhibitor, romidepsin activates the anti- apoptotic transcription factor NF-κB in A549 non-small cell lung cancer (NSCLC) cells and fails to induce significant levels of apoptosis. We also demonstrated that NF-κB inhibition with proteasome inhibitor bortezomib enhanced HDAC inhibitor induced mitochondrial injury and sensitize A549 NSCLC cells to apoptosis through the generation of reactive oxygen species. In this study, we investigate whether combined treatment with romidepsin and bortezomib would induce apoptosis in A549 NSCLC cells by activating cell cycle arrest, enhanced generation of p21 and p53, down-regulation of matrix metalloproteinases (MMPs) 2,9 also altering the acetylation status of histone proteins. Our data show that combination of romidepsin and bortezomib caused cell cycle arrest at Sub G0-G1 transition, up-regulation of cell cycle protein p21 and tumour suppressor protein p53. In addition, romidepsin down-regulated the expression of MMP-2,9 and hyperacetylation of histone H3 and H4 in bortezomib sensitised A549 NSCLC cells. From this study we concluded that romidepsin and bortezomib cooperatively inhibit A549 NSCLC cell proliferation by altering the histone acetylation status, expression of cell cycle regulators and MMPs. Romidepsin along with bortezomib might be an effective treatment approach for A549 NSCLC cells.

  15. Novel mechanism of harmaline on inducing G2/M cell cycle arrest and apoptosis by up-regulating Fas/FasL in SGC-7901 cells.

    PubMed

    Wang, Yihai; Wang, Chunhua; Jiang, Chenguang; Zeng, Hong; He, Xiangjiu

    2015-01-01

    Harmaline (HAR), a natural occurrence β-carboline alkaloid, was isolated from the seeds of Peganum harmala and exhibited potent antitumor effect. In this study, the anti-gastric tumor effects of HAR were firstly investigated in vitro and in vivo. The results strongly showed that HAR could inhibit tumor cell proliferation and induce G2/M cell cycle arrest accompanied by an increase in apoptotic cell death in SGC-7901 cancer cells. HAR could up-regulate the expressions of cell cycle-related proteins of p-Cdc2, p21, p-p53, Cyclin B and down-regulate the expression of p-Cdc25C. In addition, HAR could up-regulate the expressions of Fas/FasL, activated Caspase-8 and Caspase-3. Moreover, blocking Fas/FasL signaling could markedly inhibit the apoptosis caused by HAR, suggesting that Fas/FasL mediated pathways were involved in HAR-induced apoptosis. Interestingly, HAR could also exert on antitumor activity with a dose of 15 mg/kg/day in vivo, which was also related with cell cycle arrest. These new findings provided a framework for further exploration of HAR which possess the potential antitumor activity by inducing cell cycle arrest and apoptosis. PMID:26678950

  16. Novel mechanism of harmaline on inducing G2/M cell cycle arrest and apoptosis by up-regulating Fas/FasL in SGC-7901 cells.

    PubMed

    Wang, Yihai; Wang, Chunhua; Jiang, Chenguang; Zeng, Hong; He, Xiangjiu

    2015-12-18

    Harmaline (HAR), a natural occurrence β-carboline alkaloid, was isolated from the seeds of Peganum harmala and exhibited potent antitumor effect. In this study, the anti-gastric tumor effects of HAR were firstly investigated in vitro and in vivo. The results strongly showed that HAR could inhibit tumor cell proliferation and induce G2/M cell cycle arrest accompanied by an increase in apoptotic cell death in SGC-7901 cancer cells. HAR could up-regulate the expressions of cell cycle-related proteins of p-Cdc2, p21, p-p53, Cyclin B and down-regulate the expression of p-Cdc25C. In addition, HAR could up-regulate the expressions of Fas/FasL, activated Caspase-8 and Caspase-3. Moreover, blocking Fas/FasL signaling could markedly inhibit the apoptosis caused by HAR, suggesting that Fas/FasL mediated pathways were involved in HAR-induced apoptosis. Interestingly, HAR could also exert on antitumor activity with a dose of 15 mg/kg/day in vivo, which was also related with cell cycle arrest. These new findings provided a framework for further exploration of HAR which possess the potential antitumor activity by inducing cell cycle arrest and apoptosis.

  17. Novel mechanism of harmaline on inducing G2/M cell cycle arrest and apoptosis by up-regulating Fas/FasL in SGC-7901 cells

    PubMed Central

    Wang, Yihai; Wang, Chunhua; Jiang, Chenguang; Zeng, Hong; He, Xiangjiu

    2015-01-01

    Harmaline (HAR), a natural occurrence β-carboline alkaloid, was isolated from the seeds of Peganum harmala and exhibited potent antitumor effect. In this study, the anti-gastric tumor effects of HAR were firstly investigated in vitro and in vivo. The results strongly showed that HAR could inhibit tumor cell proliferation and induce G2/M cell cycle arrest accompanied by an increase in apoptotic cell death in SGC-7901 cancer cells. HAR could up-regulate the expressions of cell cycle-related proteins of p-Cdc2, p21, p-p53, Cyclin B and down-regulate the expression of p-Cdc25C. In addition, HAR could up-regulate the expressions of Fas/FasL, activated Caspase-8 and Caspase-3. Moreover, blocking Fas/FasL signaling could markedly inhibit the apoptosis caused by HAR, suggesting that Fas/FasL mediated pathways were involved in HAR-induced apoptosis. Interestingly, HAR could also exert on antitumor activity with a dose of 15 mg/kg/day in vivo, which was also related with cell cycle arrest. These new findings provided a framework for further exploration of HAR which possess the potential antitumor activity by inducing cell cycle arrest and apoptosis. PMID:26678950

  18. Cytoskeleton disorder and cell cycle arrest may be associated with the alteration of protein CEP135 by microgravity

    NASA Astrophysics Data System (ADS)

    Hang, Xiaoming; Sun, Yeqing; Wu, Di; Li, Yixiao; Liu, Zhiyuan

    In the past decades, alterations in the morphology, cytoskeleton and cell cycle have been observed in cells in vitro under microgravity conditions. But the underlying mechanisms are not absolutely identified yet. Our previous study on proteomic and microRNA expression profiles of zebrafish embryos exposed to simulated-microgravity has demonstrated a serial of microgravity-sensitive molecules. Centrosomal protein of 135 kDa (CEP135) was found down-regulated, but the mRNA expression level of it was up-regulated in zebrafish embryos after simulated-microgravity. However, the functional study on CEP135 is very limited and it has not been cloned in zebrafish till now. In this study, we try to determine whether the cytoskeleton disorder and cell cycle arrest is associated with the alteration of CEP135 by microgravity. Full-length cDNA of cep135 gene was firstly cloned from mitosis phase of ZF4. The sequence was analyzed and the phylogenetic tree was constructed based on the similarity to other species. Zebrafish embryonic cell line ZF4 were exposed to simulated microgravity for 24 and 48 hours, using a rotary cell culture system (RCCS) designed by NASA. Quantitative analysis by western blot showed that CEP135 expression level was significantly decreased two times after 24 hour simulated microgravity. Cell cycle detection by flow cytometer indicated ZF4 cells were blocked in G1 phase after 24 and 48 hour simulated microgravity. Moreover, double immunostained ZF4 cells with anti-tubulin and anti-CEP135antibodies demonstrated simulated microgravity could lead to cytoskeleton disorder and CEP135 abnormality. Further investigations are currently being carried out to determine whether knockdown and over-expression of CEP135 will modulate cytoskeleton and cell cycle. In vitro data in combination within vivo results might, at least in part, explain the dramatic effects of microgravity. Key Words: microgravity; CEP135; Cytoskeleton disorder; G1 arrest; ZF4 cell line

  19. Decitabine induces G2/M cell cycle arrest by suppressing p38/NF-κB signaling in human renal clear cell carcinoma

    PubMed Central

    Shang, Donghao; Han, Tiandong; Xu, Xiuhong; Liu, Yuting

    2015-01-01

    Objective: The anti-neoplastic effects of decitabine, an inhibitor of DNA promoter methylation, are beneficial for the treatment of renal cell carcinoma (RCC); however, the mechanism of action of decitabine is unclear. We analyzed gene expression profiling and identified specific pathways altered by decitabine in RCC cells. Methods: Four human RCC cell lines (ACHN, Caki-1, Caki-1, and A498) were used in this study; growth suppression of RCC cells by decitabine was analyzed using the WST-1 assay. Apoptosis and cell cycle arrest were examined using flow cytometric analysis. Gene expression of RCC cells induced by decitabine was evaluated with cDNA microarray, and potential biological pathways were selected using Ingenuity Pathway Analysis. The activity of the p38-NF-κB pathway regulated by decitabine was confirmed by Western blotting. Results: Decitabine suppresses the proliferation of RCC cells in vitro. Although decitabine did not significantly induce apoptosis, decitabine caused cell cycle arrest at G2/M in a dose-dependent manner. Gene expression regulated by decitabine in RCC cells was investigated using microarray analysis. Ubiquitin carboxyl terminal hydrolase 1 (UCHL1), interferon inducible protein 27 (IFI27), and cell division cycle-associated 2 (CDCA2) may be involved in growth suppression of RCC cells by decitabine. The phosphorylation of p38-NF-κB pathway was suppressed by decitabine in RCC cells. Conclusions: We investigated gene expression profiling and pathways modulated by decitabine in RCC cells. Decitabine was shown to suppress the growth of RCC cells via G2/M cell cycle arrest and the p38-NF-κB signaling pathway may play a role in the anti-neoplastic effect of decitabine in RCC cells. PMID:26617834

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

    PubMed

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

    2016-05-27

    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.

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

    PubMed Central

    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

  2. Retinoic acid induced growth arrest of human breast carcinoma cells requires protein kinase C alpha expression and activity.

    PubMed

    Cho, Y; Tighe, A P; Talmage, D A

    1997-09-01

    Retinoic acid inhibits proliferation of hormone-dependent, but not hormone-independent breast cancer cells. Retinoic acid-induced changes in cellular proliferation and differentiation are associated with disturbances in growth factor signaling and frequently with changes in protein kinase C expression. PKC delta, epsilon, and zeta are expressed in both hormone-dependent (T-47D) and hormone-independent (MDA-MB-231) cell lines. Retinoic acid arrested T-47D proliferation, induced PKC alpha expression and concomitantly repressed PKC zeta expression. The changes in PKC alpha and PKC zeta reflect retinoic acid-induced changes in mRNA. In contrast, retinoic acid had no effect on growth, or PKC expression in MDA-MB-231 cells. Growth arrest and the induction of PKC alpha, but not the reduction in PKC zeta, resulted from selective activation of RAR alpha. In total, these results support an important role for PKC alpha in mediating the anti-proliferative action of retinoids on human breast carcinoma cells.

  3. An Aqueous Extract of Fagonia cretica Induces DNA Damage, Cell Cycle Arrest and Apoptosis in Breast Cancer Cells via FOXO3a and p53 Expression

    PubMed Central

    Lam, Matt; Carmichael, Amtul R.; Griffiths, Helen R.

    2012-01-01

    Background Plants have proved to be an important source of anti-cancer drugs. Here we have investigated the cytotoxic action of an aqueous extract of Fagonia cretica, used widely as a herbal tea-based treatment for breast cancer. Methodology/Principal Findings Using flow cytometric analysis of cells labeled with cyclin A, annexin V and propidium iodide, we describe a time and dose-dependent arrest of the cell cycle in G0/G1 phase of the cell cycle and apoptosis following extract treatment in MCF-7 (WT-p53) and MDA-MB-231 (mutant-p53) human breast cancer cell lines with a markedly reduced effect on primary human mammary epithelial cells. Analysis of p53 protein expression and of its downstream transcription targets, p21 and BAX, revealed a p53 associated growth arrest within 5 hours of extract treatment and apoptosis within 24 hours. DNA double strand breaks measured as γ-H2AX were detected early in both MCF-7 and MDA-MB-231 cells. However, loss of cell viability was only partly due to a p53-driven response; as MDA-MB-231 and p53-knockdown MCF-7 cells both underwent cell cycle arrest and death following extract treatment. p53-independent growth arrest and cytotoxicity following DNA damage has been previously ascribed to FOXO3a expression. Here, in MCF-7 and MDA-MB-231 cells, FOXO3a expression was increased significantly within 3 hours of extract treatment and FOXO3 siRNA reduced the extract-induced loss of cell viability in both cell lines. Conclusions/Significance Our results demonstrate for the first time that an aqueous extract of Fagonia cretica can induce cell cycle arrest and apoptosis via p53-dependent and independent mechanisms, with activation of the DNA damage response. We also show that FOXO3a is required for activity in the absence of p53. Our findings indicate that Fagonia cretica aqueous extract contains potential anti-cancer agents acting either singly or in combination against breast cancer cell proliferation via DNA damage-induced FOXO3a and p53

  4. Copper-induced immunotoxicity involves cell cycle arrest and cell death in the liver.

    PubMed

    Keswani, Tarun; Mitra, Soham; Bhattacharyya, Arindam

    2015-04-01

    Inorganic copper, such as that in drinking water and copper supplements, largely bypasses the liver and enters the free copper pool of the blood directly and that promote immunosuppression. According to our previous in vivo report, we evaluate the details of the apoptotic mechanism in liver, we have investigated how copper regulates apoptotic pathways in liver. We have analyzed different protein expression by Western blotting and immunohistochemistry expression. We have also have measured mitochondrial trans-membrane potential, Annexin V assay, ROS, and CD4(+) and CD8(+) population in hepatocyte cells by flow cytometry. Copper-treated mice evidenced immunotoxicity as indicated by dose-related, distinct histomorphological changes in liver. Flow cytometric analyses revealed a dose-related increase in the percentages of hepatocyte cells in the Sub-G0/G1 state, further confirmed by Annexin V binding assay. In addition, the copper treatments altered the expression of apoptotic markers, further ROS generation and mitochondrial trans-membrane potential changes promote intrinsic pathway of apoptosis that was p53 independent. Apart from the role of inflammation, our findings also have identified the role of other partially responsible apoptotic molecules p73 that differentially changed due to copper treatment. Our study demonstrates how apoptotic pathways regulate copper-induced immunosuppression in liver.

  5. Antiproliferative activity of goniothalamin enantiomers involves DNA damage, cell cycle arrest and apoptosis induction in MCF-7 and HB4a cells.

    PubMed

    Semprebon, Simone Cristine; Marques, Lilian Areal; D'Epiro, Gláucia Fernanda Rocha; de Camargo, Elaine Aparecida; da Silva, Glenda Nicioli; Niwa, Andressa Megumi; Macedo Junior, Fernando; Mantovani, Mário Sérgio

    2015-12-25

    (R)-goniothalamin (R-GNT) is a styryl lactone that exhibits antiproliferative property against several tumor cell lines. (S)-goniothalamin (S-GNT) is the synthetic enantiomer of R-GNT, and their biological properties are poorly understood. The aim of this study was to evaluate the antiproliferative mechanisms of (R)-goniothalamin and (S)-goniothalamin in MCF-7 breast cancer cells and HB4a epithelial mammary cells. To determine the mechanisms of cell growth inhibition, we analyzed the ability of R-GNT and S-GNT to induce DNA damage, cell cycle arrest and apoptosis. Moreover, the gene expression of cell cycle components, including cyclin, CDKs and CKIs, as well as of genes involved in apoptosis and the DNA damage response were evaluated. The natural enantiomer R-GNT proved more effective in both cell lines than did the synthetic enantiomer S-GNT, inhibiting cell proliferation via cell cycle arrest and apoptosis induction, likely in response to DNA damage. The cell cycle inhibition caused by R-GNT was mediated through the upregulation of CIP/KIP cyclin-kinase inhibitors and through the downregulation of cyclins and CDKs. S-GNT, in turn, was able to cause G0/G1 cell cycle arrest and DNA damage in MCF-7 cells and apoptosis induction only in HB4a cells. Therefore, goniothalamin presents potent antiproliferative activity to breast cancer cells MCF-7. However, exposure to goniothalamin brings some undesirable effects to non-tumor cells HB4a, including genotoxicity and apoptosis induction.

  6. Cells on the run: shear-regulated integrin activation in leukocyte rolling and arrest on endothelial cells.

    PubMed

    Alon, Ronen; Ley, Klaus

    2008-10-01

    The arrest of rolling leukocytes on various target vascular beds is mediated by specialized leukocyte integrins and their endothelial immunoglobulin superfamily (IgSF) ligands. These integrins are kept in largely inactive states and undergo in situ activation upon leukocyte-endothelial contact by both biochemical and mechanical signals from flow-derived shear forces. In vivo and in vitro studies suggest that leukocyte integrin activation involves conformational alterations through inside-out signaling followed by ligand-induced rearrangements accelerated by external forces. This activation process takes place within fractions of seconds by in situ signals transduced to the rolling leukocyte as it encounters specialized endothelial-displayed chemoattractants, collectively termed arrest chemokines. In neutrophils, selectin rolling engagements trigger intermediate affinity integrins to support reversible adhesions before chemokine-triggered arrest. Different leukocyte subsets appear to use different modalities of integrin activation during rolling and arrest at distinct endothelial sites.

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

    PubMed

    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

  8. Galbanic acid decreases androgen receptor abundance and signaling and induces G1 arrest in prostate cancer cells

    PubMed Central

    Zhang, Yong; Kim, Kwan-Hyun; Zhang, Wei; Guo, Yinglu; Kim, Sung-Hoon; Lü, Junxuan

    2011-01-01

    Androgen receptor (AR) signaling is crucial for the genesis and progression of prostate cancer (PCa). We compared the growth responses of AR(+) LNCaP and LNCaP C4-2 vs. AR(−) DU145 and PC-3 PCa cell lines to galbanic acid (GBA) isolated from the resin of medicinal herb Ferula assafoetida and assessed their connection to AR signaling and cell cycle regulatory pathways. Our results showed that GBA preferentially suppressed AR(+) PCa cell growth than AR(−) PCa cells. GBA induced a caspase-mediated apoptosis that was attenuated by a general caspase inhibitor. Subapoptotic GBA down-regulated AR protein in LNCaP cells primarily through promoting its proteasomal degradation, and inhibited AR-dependent transcription without affecting AR nuclear translocation. Whereas docking simulations predicted binding of GBA to the AR ligand binding domain with similarities and differences with the AR antagonist drug bicalutamide, LNCaP cell culture assays did not detect agonist activity of GBA. GBA and bicalutamide exerted greater than additive inhibitory effect on cell growth when used together. Subapoptotic GBA induced G1 arrest associated with an inhibition of cyclin/CDK4/6 pathway, especially cyclin D1 without the causal involvement of CDK inhibitory proteins P21Cip1 and P27Kip1. In summary, the novelty of GBA as an anti-AR compound resides in the distinction between GBA and bicalutamide with respect to AR protein turnover and a lack of agonist effect. Our observations of anti-AR and cell cycle arrest actions plus the anti-angiogenesis effect reported elsewhere suggest GBA as a multi-targeting drug candidate for the prevention and therapy of PCa. PMID:21328348

  9. HDAC-inhibitor (S)-8 disrupts HDAC6-PP1 complex prompting A375 melanoma cell growth arrest and apoptosis

    PubMed Central

    Balliu, Manjola; Guandalini, Luca; Romanelli, Maria Novella; D'Amico, Massimo; Paoletti, Francesco

    2015-01-01

    Histone deacetylase inhibitors (HDACi) are agents capable of inducing growth arrest and apoptosis in different tumour cell types. Previously, we reported a series of novel HDACi obtained by hybridizing SAHA or oxamflatin with 1,4-benzodiazepines. Some of these hybrids proved effective against haematological and solid cancer cells and, above all, compound (S)-8 has emerged for its activities in various biological systems. Here, we describe the effectiveness of (S)-8 against highly metastatic human A375 melanoma cells by using normal PIG1 melanocytes as control. (S)-8 prompted: acetylation of histones H3/H4 and α-tubulin; G0/G1 and G2/M cell cycle arrest by rising p21 and hypophos-phorylated RB levels; apoptosis involving the cleavage of PARP and caspase 9, BAD protein augmentation and cytochrome c release; decrease in cell motility, invasiveness and pro-angiogenic potential as shown by results of wound-healing assay, down-regulation of MMP-2 and VEGF-A/VEGF-R2, besides TIMP-1/TIMP-2 up-regulation; and also intracellular accumulation of melanin and neutral lipids. The pan-caspase inhibitor Z-VAD-fmk, but not the antioxidant N-acetyl-cysteine, contrasted these events. Mechanistically, (S)-8 allows the disruption of cytoplasmic HDAC6-protein phosphatase 1 (PP1) complex in A375 cells thus releasing the active PP1 that dephosphorylates AKT and blocks its downstream pro-survival signalling. This view is consistent with results obtained by: inhibiting PP1 with Calyculin A; using PPP1R2-transfected cells with impaired PP1 activity; monitoring drug-induced HDAC6-PP1 complex re-shuffling; and, abrogating HDAC6 expression with specific siRNA. Altogether, (S)-8 proved very effective against melanoma A375 cells, but not normal melanocytes, and safe to normal mice thus offering attractive clinical prospects for treating this aggressive malignancy. PMID:25376115

  10. p27Kip1 Is Required to Mediate a G1 Cell Cycle Arrest Downstream of ATM following Genotoxic Stress

    PubMed Central

    Cassimere, Erica K.; Mauvais, Claire; Denicourt, Catherine

    2016-01-01

    The DNA damage response (DDR) is a coordinated signaling network that ensures the maintenance of genome stability under DNA damaging stress. In response to DNA lesions, activation of the DDR leads to the establishment of cell cycle checkpoints that delay cell-cycle progression and allow repair of the defects. The tumor suppressor p27Kip1 is a cyclin-CDK inhibitor that plays an important role in regulating quiescence in a variety of tissues. Several studies have suggested that p27Kip1 also plays a role in the maintenance of genomic integrity. Here we demonstrate that p27Kip1 is essential for the establishment of a G1 checkpoint arrest after DNA damage. We also uncovered that ATM phosphorylates p27Kip1 on a previously uncharacterized residue (Ser-140), which leads to its stabilization after induction of DNA double-strand breaks. Inhibition of this stabilization by replacing endogenous p27Kip1 with a Ser-140 phospho-mutant (S140A) significantly sensitized cells to IR treatments. Our findings reveal a novel role for p27Kip1 in the DNA damage response pathway and suggest that part of its tumor suppressing functions relies in its ability to mediate a G1 arrest after the induction of DNA double strand breaks. PMID:27611996

  11. p27Kip1 Is Required to Mediate a G1 Cell Cycle Arrest Downstream of ATM following Genotoxic Stress.

    PubMed

    Cassimere, Erica K; Mauvais, Claire; Denicourt, Catherine

    2016-01-01

    The DNA damage response (DDR) is a coordinated signaling network that ensures the maintenance of genome stability under DNA damaging stress. In response to DNA lesions, activation of the DDR leads to the establishment of cell cycle checkpoints that delay cell-cycle progression and allow repair of the defects. The tumor suppressor p27Kip1 is a cyclin-CDK inhibitor that plays an important role in regulating quiescence in a variety of tissues. Several studies have suggested that p27Kip1 also plays a role in the maintenance of genomic integrity. Here we demonstrate that p27Kip1 is essential for the establishment of a G1 checkpoint arrest after DNA damage. We also uncovered that ATM phosphorylates p27Kip1 on a previously uncharacterized residue (Ser-140), which leads to its stabilization after induction of DNA double-strand breaks. Inhibition of this stabilization by replacing endogenous p27Kip1 with a Ser-140 phospho-mutant (S140A) significantly sensitized cells to IR treatments. Our findings reveal a novel role for p27Kip1 in the DNA damage response pathway and suggest that part of its tumor suppressing functions relies in its ability to mediate a G1 arrest after the induction of DNA double strand breaks. PMID:27611996

  12. Carboxylation of multiwalled carbon nanotube attenuated the cytotoxicity by limiting the oxidative stress initiated cell membrane integrity damage, cell cycle arrestment, and death receptor mediated apoptotic pathway.

    PubMed

    Liu, Zhenbao; Liu, Yanfei; Peng, Dongming

    2015-08-01

    In this study, the effects of carboxylated multiwalled carbon nanotubes (MWCNTs-COOH) on human normal liver cell line L02 was compared with that of pristine multiwalled carbon nanotubes (p-MWCNTs). It was shown that compared with MWCNTs-COOH, p-MWCNTs induced apoptosis, reduced the level of intracellular antioxidant glutathione more significantly, and caused severer cell membrane damage as demonstrated by lactate dehydrogenase leakage. Cell cycles were arrested by both MWCNTs, while p-MWCNTs induced higher ratio of G0/G1 phase arrestment as compared with MWCNTs-COOH. Caspase-8 was also activated after both MWCNTs exposure, indicating extrinsic apoptotic pathway was involved in the apoptosis induced by MWCNTs exposure, more importantly, MWCNTs-COOH significantly reduced the activation of caspase-8 as compared with p-MWCNTs. All these results suggested that MWCNTs-COOH might be safer for in vivo application as compared with p-MWCNTs.

  13. Inhibition of constitutive NF-kappa B activation in mantle cell lymphoma B cells leads to induction of cell cycle arrest and apoptosis.

    PubMed

    Pham, Lan V; Tamayo, Archito T; Yoshimura, Linda C; Lo, Piao; Ford, Richard J

    2003-07-01

    Constitutive activation of the NF-kappaB has been documented to be involved in the pathogenesis of many human malignancies, including hemopoietic neoplasms. In this study, we examined the status of NF-kappaB in two non-Hodgkin's lymphoma cell lines derived from mantle cell lymphoma (MCL) samples and in patient MCL biopsy specimens by EMSA and confocal microscopic analysis. We observed that NF-kappaB is constitutively activated in both the MCL cell lines and in the MCL patient biopsy cells. Since NF-kappaB has been shown to play an important role in a variety of cellular processes, including cell cycle regulation and apoptosis, targeting the NF-kappaB pathways for therapy may represent a rational approach in this malignancy. In the MCL cell lines, inhibition of constitutive NF-kappaB by the proteasome inhibitor PS-341 or a specific pIkappaBalpha inhibitor, BAY 11-7082, led to cell cycle arrest in G(1) and rapid induction of apoptosis. Apoptosis was associated with the down-regulation of bcl-2 family members bcl-x(L) and bfl/A1, and the activation of caspase 3, that mediates bcl-2 cleavage, resulting in the release of cytochrome c from the mitochondria. PS-341or BAY 11-induced G(1) cell cycle arrest was associated with the inhibition of cyclin D1 expression, a molecular genetic marker of MCL. These studies suggest that constitutive NF-kappaB expression plays a key role in the growth and survival of MCL cells, and that PS-341 and BAY 11 may be useful therapeutic agents for MCL, a lymphoma that is refractory to most current chemotherapy regimens.

  14. p21(Waf1) is required for cellular senescence but not for cell cycle arrest induced by the HDAC inhibitor sodium butyrate.

    PubMed

    Romanov, V S; Abramova, M V; Svetlikova, S B; Bykova, T V; Zubova, S G; Aksenov, N D; Fornace, A J; Pospelova, T V; Pospelov, V A

    2010-10-01

    Cell senescence is characterized by senescent morphology and permanent loss of proliferative potential. HDAC inhibitors (HDACI) induce senescence and/or apoptosis in many types of tumor cells. Here, we studied the role of cyclin-kinase inhibitor p21(waf1) (Cdkn1n gene) in cell cycle arrest, senescence markers (cell hypertrophy, SA-βGal staining and accumulation of γH2AX foci) in p21(Waf1+/+) versus p21(Waf1-/-) mouse embryonic fibroblast cells transformed with E1A and cHa-Ras oncogenes (mERas). While short treatment with the HDACI sodium butyrate (NaB) induced a reversible G(1) cell cycle arrest in both parental and p21(Waf1-/-) cells, long-term treatment led to dramatic changes in p21(Waf1+/+) cells only: cell cycle arrest became irreversible and cells become hypertrophic, SA-βGal-positive and accumulated γH2AX foci associated with mTORC1 activation. The p21(Waf1+/+) cells lost their ability to migrate into the wound and through a porous membrane. Suppression of migration was accompanied by accumulation of vinculin-staining focal adhesions and Ser3-phosphorylation of cofilin, incapable for F-actin depolymerization. In contrast, the knockout of the p21(Waf1) abolished most of the features of NaB-induced senescence, including irreversibility of cell cycle arrest, hypertrophy, additional focal adhesions and block of migration, γH2AX foci accumulation and SA-βGal staining. Rapamycin, a specific inhibitor of mTORC1 kinase, decreased cellular hypertrophy, canceled coffilin phosphorylation and partially restored cell migration in p21(Waf1+/+) cells. Taken together, our data indicate a new role of p21(Waf1) in cell senescence, which may be connected not only with execution of cell cycle arrest, but also with the development of mTOR-dependent markers of cellular senescence.

  15. Induction of autophagy by dimethyl cardamonin is associated with proliferative arrest in human colorectal carcinoma HCT116 and LOVO cells.

    PubMed

    Ko, Hyeonseok; Kim, Young-Joo; Amor, Evangeline C; Lee, Jong Wha; Kim, Han-Cheon; Kim, Hee Ju; Yang, Hyun Ok

    2011-09-01

    Dimethyl cardamonin (2',4'-dihydroxy-6'-methoxy-3',5'-dimethylchalcone; DMC) is a naturally occurring chalcone, and it is the major compound isolated from the leaves of Syzygium samarangense (Blume) Merr. & L.M. Perry (Myrtaceae). Experiments were conducted to determine the effects of DMC on cell proliferation, cell-cycle distribution, and programmed cell death in cultures of human colorectal carcinoma HCT116 and LOVO cells. Results showed that DMC inhibited HCT116 and LOVO cell proliferation and induced G(2) /M cell cycle arrest, which was associated with the conversion of microtubule associated protein light chain 3 (LC3)-I-LC3-II, an autophagosome marker, and the incorporation of monodansylcadaverine (MDC), a marker for the acidic compartment of autolysosomes or acidic vesicular organelles. The treatment of HCT116 and LOVO cells using a combination of DMC with an autophagy inhibitor, such as 3-methyladenine (3-MA), beclin 1 siRNA, or atg5 siRNA, suppressed the effect of DMC-mediated anti-proliferation. These results imply that DMC can suppress colorectal carcinoma HCT116 and LOVO cell proliferation through a G(2) /M phase cell-cycle delay, and can induce autophagy, the hallmark of Type II programmed cell death (PCD). Taken together, our results suggest that DMC may be an effective chemotherapeutic agent for HCT116 and LOVO colorectal carcinoma cells.

  16. 2-(3,5-Dihydroxyphenyl)-6-hydroxybenzothiazole arrests cell growth and cell cycle and induces apoptosis in breast cancer cell lines.

    PubMed

    Rajabi, Mehdi

    2012-03-01

    2-Arylbenzothiazoles are an important class of bicyclic privileged substructures present in various natural or synthetic compounds that have been shown to possess anticancer, antifungal, antibacterial, anti-inflammatory, and antiallergic activities. This study examined the antiproliferative properties of 2-(3,5-dihydroxyphenyl)-6-hydroxybenzothiazole (DH) and its molecular mechanism of action in human breast cancer MDA-MB-231 cells. DH inhibits the growth of MDA-MB-231 cells with an IC(50) value of 25 μM in a dose/time-dependent manner as measured by the microculture tetrazolium method. Cell cycle analysis by flow cytometry showed that DH-induced growth arrest could be associated to apoptosis in MDA-MB-231 cells. PMID:21838530

  17. 6-Gingerol Inhibits Growth of Colon Cancer Cell LoVo via Induction of G2/M Arrest.

    PubMed

    Lin, Ching-Bin; Lin, Chun-Che; Tsay, Gregory J

    2012-01-01

    6-Gingerol, a natural component of ginger, has been widely reported to possess antiinflammatory and antitumorigenic activities. Despite its potential efficacy against cancer, the anti-tumor mechanisms of 6-gingerol are complicated and remain sketchy. In the present study, we aimed to investigate the anti-tumor effects of 6-gingerol on colon cancer cells. Our results revealed that 6-gingerol treatment significantly reduced the cell viability of human colon cancer cell, LoVo, in a dose-dependent manner. Further flow cytometric analysis showed that 6-gingerol induced significant G2/M phase arrest and had slight influence on sub-G1 phase in LoVo cells. Therefore, levels of cyclins, cyclin-dependent kinases (CDKs), and their regulatory proteins involved in S-G2/M transition were investigated. Our findings revealed that levels of cyclin A, cyclin B1, and CDK1 were diminished; in contrast, levels of the negative cell cycle regulators p27(Kip1) and p21(Cip1) were increased in response to 6-gingerol treatment. In addition, 6-gingerol treatment elevated intracellular reactive oxygen species (ROS) and phosphorylation level of p53. These findings indicate that exposure of 6-gingerol may induce intracellular ROS and upregulate p53, p27(Kip1), and p21(Cip1) levels leading to consequent decrease of CDK1, cyclin A, and cyclin B1 as result of cell cycle arrest in LoVo cells. It would be suggested that 6-gingerol should be beneficial to treatment of colon cancer.

  18. Triptolide Abrogates Growth of Colon Cancer and Induces Cell Cycle Arrest by Inhibiting Transcriptional Activation of E2F

    PubMed Central

    Chugh, Rohit; Skube, Steven J; Majumder, Kaustav; Banerjee, Sulagna; Sangwan, Veena; Li, Lihua; Dawra, Rajinder; Subramanian, Subbaya; Saluja, Ashok; Dudeja, Vikas

    2016-01-01

    Background Despite significant progress in diagnostics and therapeutics, over fifty thousand patients die from colorectal cancer annually. Hence there is urgent need for new lines of treatment. Triptolide, a natural compound isolated from the Chinese herb Tripterygium wilfordii, is effective against multiple cancers. We have synthesized a water soluble analog of triptolide, named Minnelide, which is currently in phase I trial against pancreatic cancer. The aims of the current study were to evaluate whether triptolide/Minnelide is effective against colorectal cancer and to elucidate the mechanism by which triptolide induces cell death in colorectal cancer. Methods Efficacy of Minnelide was evaluated in subcutaneous xenograft and liver metastasis model of colorectal cancer. For mechanistic studies colon cancer cell lines HCT116 and HT29 were treated with triptolide and the effect on viability, caspase activation, annexin positivity, lactate dehydrogenase(LDH) release and cell cycle progression was evaluated. Effect of triptolide on E2F transcriptional activity, mRNA levels of E2F dependent genes, E2F1-Rb binding and proteins levels of regulator of G1-S transition was also measured. DNA binding of E2F1 was evaluated by chromatin immunoprecipitation assay. Results Triptolide decreased colon cancer cell viability in a dose- and time-dependent fashion. Minnelide markedly inhibited the growth of colon cancer in the xenograft and liver metastasis model of colon cancer and more than doubles the median survival of animals with liver metastases from colon cancer. Mechanistically we demonstrate that at low concentrations, triptolide induces apoptotic cell death but at higher concentrations it induces cell cycle arrest. Our data suggest that triptolide is able to induce G1 cell cycle arrest by inhibiting transcriptional activation of E2F1. Our data also show that triptolide downregulates E2F activity by potentially modulating events downstream of DNA binding. Conclusion

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

    PubMed

    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.

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

    PubMed

    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

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

    PubMed Central

    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

  2. Viscum Album Var Hot Water Extract Mediates Anti-cancer Effects through G1 Phase Cell Cycle Arrest in SK-Hep1 Human Hepatocarcinoma cells.

    PubMed

    dela Cruz, Joseph Flores; Kim, Yeon Soo; Lumbera, Wenchie Marie Lara; Hwang, Seong Gu

    2015-01-01

    Viscum album var (VAV) also known as mistletoe, has long been categorized as a traditional herbal medicine in Asia. In addition to its immunomodulating activities, mistletoe has also been used in the treatment of chronic hepatic disorders in China and Korea. There are numerous reports showing that VAV possesses anti-cancer effects, however influence on human hepatocarcinoma has never been elucidated. In the present study, hot water extracts of VAV was evaluated for its potential anti-cancer effect in vitro. SK-Hep1 cells were treated with VAV (50-400 ug/ml) for both 24 and 48 hours then cell viability was measured by cell counting kit-8 (CCK-8). Flow cytometry analysis was used to measure the proportion of SK-Hep1 in the different stages of cell cycle. RT-PCR and Western blot analysis were conducted to measure expression of cell cycle arrest related genes and proteins respectively. VAV dose dependently inhibited the proliferation of SK-Hep1 cells without any cytotoxicity with normal Chang liver cell (CCL-13). Flow cytometry analysis showed that VAV extract inhibited the cell cycle of SK-Hep1 cells via G1 phase arrest. RT-PCR and Western blot analysis both revealed that cyclin dependent kinase 2 (Cdk2) and cyclin D1 gene expression were significantly down regulated while p21 was upregulated dose dependently by VAV treatment. Combined down regulation of Cdk2, Cyclin D1 and up regulation of p21 can result in cell death. These results indicate that VAV showed evidence of anti-cancer activity through G1 phase cell cycle arrest in SK-Hep1 cells. PMID:26434853

  3. Protective effect of N-acetylcysteine against DNA damage and S-phase arrest induced by ochratoxin A in human embryonic kidney cells (HEK-293).

    PubMed

    Yang, Qian; Shi, Lei; Huang, Kunlun; Xu, Wentao

    2014-08-01

    N-acetylcysteine (NAC) has recently gained particular interest as a beneficial antioxidant. This study investigated the protective effects of NAC against ochratoxin A (OTA)-induced DNA damage and S-phase arrest in human embryonic kidney cells (HEK-293). OTA exposure results in nephrotoxicity, hepatotoxicity as well as immunotoxicity; and, in the present study, the toxicity of OTA toward HEK-293 cells was explored by analyzing the involvement of the oxidative pathway. It was found that OTA treatment led to oxidative damage; meanwhile, OTA treatment induced significant DNA damage and S-phase arrest by down-regulating cyclin A2, cyclin E1, and CDK2 expression. However, NAC pretreatment alleviated OTA-induced ROS overproduction, the loss of mitochondrial membrane potential (ΔΨm), and the decrease in superoxide dismutase (SOD) activity. NAC pretreatment was also discovered to attenuate OTA-induced DNA damage using the comet assay and by determining the expression of γ-H2AX. In addition, NAC pretreatment partly ameliorated OTA-induced S-phase arrest by preventing the down-regulation of cyclin A2, cyclin E1 and CDK2 expression in HEK-293 cells. All of these results demonstrated that oxidative damage was involved in OTA-induced DNA damage and cell cycle arrest in HEK-293 cells. Therefore, NAC has the potential to reverse the DNA damage and S-phase arrest induced by OTA.

  4. Programmed cell death 2 protein induces gastric cancer cell growth arrest at the early S phase of the cell cycle and apoptosis in a p53-dependent manner.

    PubMed

    Zhang, Jian; Wei, Wei; Jin, Hui-Cheng; Ying, Rong-Chao; Zhu, A-Kao; Zhang, Fang-Jie

    2015-01-01

    Programmed cell death 2 (PDCD2) is a highly conserved nuclear protein, and aberrant PDCD2 expression alters cell apoptosis. The present study aimed to investigate PDCD2 expression in gastric cancer. Tissue specimens from 34 gastric cancer patients were collected for analysis of PDCD2 expression using immunohistochemistry, western blotting and qRT-PCR. Gastric cancer cell lines (a p53-mutated MKN28 line and a wild-type p53 MKN45 line) were used to assess the effects of PDCD2 overexpression. p53-/- nude mice were used to investigate the effect of PDCD2 on ultraviolet B (UVB)-induced skin carcinogenesis. The data showed that PDCD2 expression was reduced in gastric cancer tissue specimens, and loss of PDCD2 expression was associated with the poor survival of patients. PDCD2 expression induced gastric cancer cell growth arrest at the early S phase of the cell cycle and apoptosis. The antitumor effects of PDCD2 expression were dependent on p53 expression in gastric cancer cells. Moreover, PDCD2 expression inhibited activity of the ATM/Chk1/2/p53 signaling pathway. In addition, PDCD2 expression suppressed UVB-induced skin carcinogenesis in p53+/+ nude mice, but not in p53-/- mice. The data from the present study demonstrated that loss of PDCD2 expression could contribute to gastric cancer development and progression and that PDCD2-induced gastric cancer cell growth arrest at the early S phase of the cell cycle and apoptosis are p53-dependent. PMID:25334010

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

    PubMed Central

    Sayed, Douaa; Al-Sadoon, Mohamed K.

    2012-01-01

    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. PMID:23304253

  6. Furano-1,2-naphthoquinone inhibits EGFR signaling associated with G2/M cell cycle arrest and apoptosis in A549 cells.

    PubMed

    Su, J C; Lin, K L; Chien, C M; Tseng, C H; Chen, Y L; Chang, L S; Lin, S R

    2010-12-01

    Furano-1,2-naphthoquinone (FNQ), prepared from 2-hydroxy-1,4-naphthoquinone and chloroacetaldehyde in an efficient one-pot reaction, exhibits an anti-carcinogenic effect. FNQ exerted anti-proliferative activity with the G(2)/M cell cycle arrest and apoptosis in A549 cells. FNQ-induced G(2)/M arrest was correlated with a marked decrease in the expression levels of cyclin A and cyclin B, and their activating partner cyclin-dependent kinases (Cdk) 1 and 2 with concomitant induction of p53, p21, and p27. FNQ-induced apoptosis was accompanied with Bax up-regulation and the down-regulation of Bcl-2, X-linked inhibitor of apoptosis (XIAP), and survivin, resulting in cytochrome c release and sequential activation of caspase-9 and caspase-3. Western blot analysis revealed that FNQ suppressed EGFR phosphorylation and JAK2, STAT3, and STAT5 activation, but increased in activation of p38 MAPK and c-Jun NH2-terminal kinase (JNK) stress signal. The combined treatment of FNQ with AG1478 (a specific EGFR inhibitor) significantly enhanced the G(2)/M arrest and apoptosis, and also led to up-regulation in Bax, p53, p21, p27, release of mitochondrial cytochrome c, and down-regulation of Bcl-2, XIAP, survivin, cyclin A, cyclin B, Cdk1, and Cdk2 in A549 cells. These findings suggest that FNQ-mediated cytotoxicity of A549 cell related with the G(2)/M cell cycle arrest and apoptosis via inactivation of EGFR-mediated signaling pathway. PMID:21104938

  7. PD98059 Protects Brain against Cells Death Resulting from ROS/ERK Activation in a Cardiac Arrest Rat Model

    PubMed Central

    Nguyen Thi, Phuong Anh; Chen, Meng-Hua; Li, Nuo; Zhuo, Xiao-Jun; Xie, Lu

    2016-01-01

    The clinical and experimental postcardiac arrest treatment has not reached therapeutic success. The present study investigated the effect of PD98059 (PD) in rats subjected to cardiac arrest (CA)/cardiopulmonary resuscitation (CPR). Experimental rats were divided randomly into 3 groups: sham, CA, and PD. The rats except for sham group were subjected to CA for 5 min followed by CPR operation. Once spontaneous circulation was restored, saline and PD were injected in CA and PD groups, respectively. The survival rates and neurologic deficit scores (NDS) were observed, and the following indices of brain tissue were evaluated: ROS, MDA, SOD, p-ERK1/2/ERK1/2, caspase-3, Bax, Bcl-2, TUNEL positive cells, and double fluorescent staining of p-ERK/TUNEL. Our results indicated that PD treatment significantly reduced apoptotic neurons and improved the survival rates and NDS. Moreover, PD markedly downregulated the ROS, MDA, p-ERK, and caspase-3, Bax and upregulated SOD and Bcl-2 levels. Double staining p-ERK/TUNEL in choroid plexus and cortex showed that cell death is dependent on ERK activation. The findings in present study demonstrated that PD provides neuroprotection via antioxidant activity and antiapoptosis in rats subjected to CA/CPR. PMID:27069530

  8. p19ARF-independent induction of p53 and cell cycle arrest by Raf in murine keratinocytes

    PubMed Central

    Roper, Elizabeth; Weinberg, Wendy; Watt, Fiona M.; Land, Hartmut

    2001-01-01

    In tumorigenesis of the skin, activated Ras co-operates with mutations that inactivate the tumour suppressor p53, but the molecular basis for this co-operation remains unresolved. Here we show that activation of the Raf/MAP kinase pathway in primary mouse keratinocytes leads to a p53 and p21Cip1-dependent cycle arrest and to terminal differentiation. Raf activation in keratinocytes lacking p53 or p21Cip1 genes leads to expression of differentiation markers, but the cells do not cease to proliferate. Thus, loss of p53 or p21Cip1 function is necessary to disable growth-inhibitory Raf/MAP kinase signalling. Activation of oncogenes, including Ras, has been reported to stabilize and activate p53 via induction of the tumour suppressor p19ARF. However, the response to Raf in p19ARF–/– keratinocytes was indistinguishable from wild-type controls. Thus, p19ARF is not essential for Raf-induced p53 induction and cell cycle arrest in keratinocytes, indicating that oncogenes engage p53 activity via multiple mechanisms. PMID:11258707

  9. The cytotoxic activities of 7-isopentenyloxycoumarin on 5637 cells via induction of apoptosis and cell cycle arrest in G2/M stage

    PubMed Central

    2014-01-01

    Background Bladder cancer is the second common malignancy of genitourinary tract, and transitional cell carcinomas (TCCs) account for 90% of all bladder cancers. Due to acquired resistance of TCC cells to a wide range of chemotherapeutic agents, there is always a need for search on new compounds for treatment of these cancers. Coumarins represent a group of natural compounds, which some of them have exerted valuable anti-tumor activities. The current study was designed to evaluate anti-tumor properties and mechanism of action of 7-isopentenyloxycoumarin, a prenyloxycoumarin, on 5637 cells (a TCC cell line). Results MTT results revealed that the cytotoxic effects of 7-isopentenyloxycoumarin on 5637 cancerous cells were more prominent in comparison to HDF-1 normal cells. This coumarin increased the amount of chromatin condensation and DNA damage in 5637 cells by 58 and 33%, respectively. The results also indicated that it can induce apoptosis most probably via activation of caspase-3 in these cells. Moreover, propidium iodide staining revealed that 7-isopentenyloxycoumarin induced cell cycle arrest at G2/M stage, after 24 h of treatment. Conclusion Our results indicated that 7-isopentenyloxycoumarin had selective toxic effects on this bladder cancer cell line and promoted its effects by apoptosis induction and cell cycle arrest. This coumarin can be considered for further studies to reveal its exact mechanism of action and also its anti-cancer effects in vivo. PMID:24393601

  10. Umbelliferone exhibits anticancer activity via the induction of apoptosis and cell cycle arrest in HepG2 hepatocellular carcinoma cells.

    PubMed

    Yu, Shi-Min; Hu, Dong-Hui; Zhang, Jian-Jun

    2015-09-01

    Hepatocellular carcinoma (HCC) is a highly malignant tumor, associated with poor patient prognoses, and high rates of morbidity and mortality. To date, the therapeutic strategies available for the treatment of HCC remain limited. The present study aimed to elucidate the anticancer activity of umbelliferone, a naturally occurring coumarin derivative isolated from Ferula communis, against the HepG2 HCC cell line. A 3‑(4,5‑dimthylthaizol‑2‑yl)‑2,5, diphenyltetrazolium bromide assay was used to evaluate cell viability following umbelliferone treatment, and the effects of umbelliferone on cell cycle progression and apoptosis were evaluated using flow cytometry. The presence of morphological features characteristic of apoptosis, including cell shrinkage, membrane blebbing, nuclear condensation and apoptotic body formation, were evaluated in HepG2 cells following umbelliferone treatment. Cell cycle analysis conducted via propidium iodide (PI) staining indicated that umbelliferone treatment induced cell cycle arrest at S phase in HepG2 cells. Analysis with Annexin V and PI staining revealed that umbelliferone induced apoptotic events in HepG2 cells in a concentration‑dependant manner (0‑50 µM). Umbelliferone also induced dose‑dependant DNA fragmentation. In conclusion, umbelliferone was found to exhibit significant anticancer effects via the induction of apoptosis, cell cycle arrest and DNA fragmentation in HepG2 cancer cells. PMID:25997538

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

    PubMed

    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

  12. RNA interference-mediated knockdown of brain-derived neurotrophic factor (BDNF) promotes cell cycle arrest and apoptosis in B-cell lymphoma cells.

    PubMed

    Xia, D; Li, W; Zhang, L; Qian, H; Yao, S; Qi, X

    2014-01-01

    Brain-derived neurotrophic factor (BDNF) is a member of the neurotrophin superfamily that has been reported to be involved in a number of neurological and psychological situations. Recently, high expression level of BDNF is observed in diverse human malignancies, delineating a role of BDNF in tumorigenesis. Nevertheless, its effect on B-cell lymphoma remains unclear. In this study, RNA interference technology mediated by short hairpin RNA (shRNA) was performed to inhibit endogenous BDNF expression in B-cell lymphoma cells. Results showed that knockdown of BDNF reduced cell growth and proliferation of Raji and Ramos cells. Furthermore, down-regulation of BDNF induced a cell cycle arrest at G0/G1 phase in Raji cells, and consequently led to cell apoptosis in vitro. Meanwhile, down-regulation of Bcl-2 and up-regulation of Bax, activated caspase-3 and caspase-9 and cleaved poly (ADP-ribose) polymerase (PARP) were observed in Raji cells when endogenous BDNF was inhibited. Besides, we also found that suppression of BDNF in Raji cells increased their sensitivity to chemotherapeutic drug, 5-Fluorouracil (5-FU). Our research provides a promising therapeutic strategy for human B-cell lymphoma by targeting BDNF.

  13. Remyelinating Oligodendrocyte Precursor Cell miRNAs from the Sfmbt2 Cluster Promote Cell Cycle Arrest and Differentiation

    PubMed Central

    Kuypers, Nicholas J.; Bankston, Andrew N.; Howard, Russell M.; Beare, Jason E.

    2016-01-01

    Oligodendrocyte (OL) loss contributes to the functional deficits underlying diseases with a demyelinating component. Remyelination by oligodendrocyte progenitor cells (OPCs) can restore these deficits. To understand the role that microRNAs (miRNAs) play in remyelination, 2′,3′-cyclic-nucleotide 3′-phosphodiesterase-EGFP+ mice were treated with cuprizone, and OPCs were sorted from the corpus callosum. Microarray analysis revealed that Sfmbt2 family miRNAs decreased during cuprizone treatment. One particular Sfmbt2 miRNA, miR-297c-5p, increased during mouse OPC differentiation in vitro and during callosal development in vivo. When overexpressed in both mouse embryonic fibroblasts and rat OPCs (rOPCs), cell cycle analysis revealed that miR-297c-5p promoted G1/G0 arrest. Additionally, miR-297c-5p transduction increased the number of O1+ rOPCs during differentiation. Luciferase reporter assays confirmed that miR-297c-5p targets cyclin T2 (CCNT2), the regulatory subunit of positive transcription elongation factor b, a complex that inhibits OL maturation. Furthermore, CCNT2-specific knockdown promoted rOPC differentiation while not affecting cell cycle status. Together, these data support a dual role for miR-297c-5p as both a negative regulator of OPC proliferation and a positive regulator of OL maturation via its interaction with CCNT2. SIGNIFICANCE STATEMENT This work describes the role of oligodendrocyte progenitor cell (OPC) microRNAs (miRNAs) during remyelination and development in vivo and differentiation in vitro. This work highlights the importance of miRNAs to OPC biology and describes miR-297c-5p, a novel regulator of OPC function. In addition, we identified CCNT2 as a functional target, thus providing a mechanism by which miR-297c-5p imparts its effects on differentiation. These data are important, given our lack of understanding of OPC miRNA regulatory networks and their potential clinical value. Therefore, efforts to understand the role of miR-297c-5p

  14. DNA damage and S phase arrest induced by Ochratoxin A in human embryonic kidney cells (HEK 293).

    PubMed

    Yang, Qian; He, Xiaoyun; Li, Xiaohong; Xu, Wentao; Luo, Yunbo; Yang, Xuan; Wang, Yan; Li, Yingcong; Huang, Kunlun

    2014-07-01

    Ochratoxin A (OTA) is a ubiquitous mycotoxin with potential nephrotoxic, hepatotoxic and immunotoxic effects. The mechanisms underlying the nephrotoxicity of OTA remain obscure. To investigate DNA damage and the changes of the cell cycle distribution induced by OTA, human embryonic kidney cells (HEK 293 cells) were incubated with various concentrations of OTA for 24h in vitro. The results indicated that OTA treatment led to the production of reactive oxygen species (ROS) and to a decrease of the mitochondrial membrane potential (ΔΨm). OTA-induced DNA damage in HEK 293 cells was evidenced by DNA comet tails formation and increased expression of γ-H2AX. In addition, OTA could induce cell cycle arrest at the S phase in HEK 293 cells. The expression of key cell cycle regulatory factors that were critical to the S phase, including cyclin A2, cyclin E1, and CDK2, were further detected. The expression of cyclin A2, cyclin E1, and CDK2 were significantly decreased by OTA treatment at both the mRNA and protein levels. The apoptosis of HEK 293 cells after OTA treatment was observed using Hoechst 33342 staining. The results confirmed that OTA did induce apoptosis in HEK 293 cells. In conclusion, our results provided new insights into the molecular mechanisms by which OTA might promote nephrotoxicity.

  15. Citric acid induces cell-cycle arrest and apoptosis of human immortalized keratinocyte cell line (HaCaT) via caspase- and mitochondrial-dependent signaling pathways.

    PubMed

    Ying, Tsung-Ho; Chen, Chia-Wei; Hsiao, Yu-Ping; Hung, Sung-Jen; Chung, Jing-Gung; Yang, Jen-Hung

    2013-10-01

    Citric acid is an alpha-hydroxyacid (AHA) widely used in cosmetic dermatology and skincare products. However, there is concern regarding its safety for the skin. In this study, we investigated the cytotoxic effects of citric acid on the human keratinocyte cell line HaCaT. HaCaT cells were treated with citric acid at 2.5-12.5 mM for different time periods. Cell-cycle arrest and apoptosis were investigated by 4,6-diamidino-2-phenylindole dihydrochloride (DAPI) staining, flow cytometry, western blot and confocal microscopy. Citric acid not only inhibited proliferation of HaCaT cells in a dose-dependent manner, but also induced apoptosis and cell cycle-arrest at the G2/M phase (before 24 h) and S phase (after 24 h). Citric acid increased the level of Bcl-2-associated X protein (BAX) and reduced the levels of B-cell lymphoma-2 (BCL-2), B-cell lymphoma-extra large (BCL-XL) and activated caspase-9 and caspase-3, which subsequently induced apoptosis via caspase-dependent and caspase-independent pathways. Citric acid also activated death receptors and increased the levels of caspase-8, activated BH3 interacting-domain death agonist (BID) protein, Apoptosis-inducing factor (AIF), and Endonuclease G (EndoG). Therefore, citric acid induces apoptosis through the mitochondrial pathway in the human keratinocyte cell line HaCaT. The study results suggest that citric acid is cytotoxic to HaCaT cells via induction of apoptosis and cell-cycle arrest in vitro.

  16. Arsenic trioxide and interferon-alpha synergize to induce cell cycle arrest and apoptosis in human T-cell lymphotropic virus type I-transformed cells.

    PubMed

    Bazarbachi, A; El-Sabban, M E; Nasr, R; Quignon, F; Awaraji, C; Kersual, J; Dianoux, L; Zermati, Y; Haidar, J H; Hermine, O; de Thé, H

    1999-01-01

    Human T-cell lymphotropic virus type I (HTLV-I) is the causative agent of adult T-cell leukemia/lymphoma (ATL). ATL is an aggressive proliferation of mature activated T cells associated with a poor prognosis. The combination of the antiviral agents, zidovudine (AZT) and interferon (IFN), is a potent treatment of ATL. Recently, arsenic trioxide (As) was shown to be an effective treatment of acute promyelocytic leukemia (APL). We have tested the effects of the combination of As and IFN on cell proliferation, cell cycle phases distribution, and apoptosis in ATL-derived or control T-cell lines. A high synergistic effect between IFN and As was observed in ATL-derived cell lines in comparison to the control cell lines, with a dramatic inhibition of cell proliferation, G1 arrest, and induction of apoptosis. Similar results were obtained with fresh leukemia cells derived from an ATL patient. Although the mechanisms involved are unclear, these results could provide a rational basis for combined As and IFN treatments in ATL. PMID:9864171

  17. Induction of apoptosis, stimulation of cell-cycle arrest and inhibition of angiogenesis make human amnion-derived cells promising sources for cell therapy of cancer.

    PubMed

    Niknejad, Hassan; Yazdanpanah, Ghasem; Ahmadiani, Abolhassan

    2016-03-01

    Amniotic membrane (AM), the nearest layer of fetal membranes to the fetus, contains two types of cells with unique characteristics that make them excellent candidates for clinical applications. Amniotic epithelial and mesenchymal cells have low immunogenicity, anti-inflammation, anti-fibrosis and anti-bacterial properties and no ethical issues. Although amniotic cells have stem cell properties and express transcription factors specific for pluripotent stem cells, they are not tumorigenic after transplantation. In the last decade, a new line of research has been initiated with a focus on the anti-proliferative effects of amniotic epithelial and mesenchymal cells on tumor growth. Amnion-derived epithelial and mesenchymal cells inhibit tumor growth and invasion through three pathways: the induction of apoptosis, the stimulation of cell-cycle arrest and the inhibition of angiogenesis. In this review, the various aspects of the anti-cancer properties of amnion-derived cells and the underlying mechanisms are discussed with emphasis on the translation of the cell therapy of cancer from experimental into clinical practice. PMID:26846225

  18. Cell type-specific targeted mutations of Kras and Pten document proliferation arrest in granulosa cells versus oncogenic insult to ovarian surface epithelial cells.

    PubMed

    Fan, Heng-Yu; Liu, Zhilin; Paquet, Marilene; Wang, Jinrong; Lydon, John P; DeMayo, Francesco J; Richards, JoAnne S

    2009-08-15

    The small G-protein KRAS is crucial for mediating gonadotropin-induced events associated with ovulation. However, constitutive expression of KrasG12D in granulosa cells disrupted normal follicle development leading to the persistence of abnormal follicle-like structures containing nonmitotic cells. To determine what factors mediate this potent effect of KrasG12D, gene profiling analyses were done. We also analyzed KrasG12D;Cyp19-Cre and KrasG12;Pgr-Cre mutant mouse models that express Cre prior to or after the initiation of granulosa cell differentiation, respectively. KrasG12D induced cell cycle arrest in granulosa cells of the KrasG12D;Cyp19-Cre mice but not in the KrasG12D;Pgr-Cre mice, documenting the cell context-specific effect of KrasG12D. Expression of KrasG12D silenced the Kras gene, reduced cell cycle activator genes, and impaired the expression of granulosa cell and oocyte-specific genes. Conversely, levels of PTEN and phosphorylated p38 mitogen-activated protein kinase (MAPK) increased markedly in the mutant granulosa cells. Because disrupting Pten in granulosa cells leads to increased proliferation and survival, Pten was disrupted in the KrasG12D mutant mice. The Pten/Kras mutant mice were infertile but lacked granulosa cell tumors. By contrast, the Ptenfl/fl;KrasG12D;Amhr2-Cre mice developed aggressive ovarian surface epithelial cell tumors that did not occur in the Ptenfl/fl;KrasG12D;Cyp19-Cre or Ptenfl/fl;KrasG12D;Pgr-Cre mouse strains. These data document unequivocally that Amhr2-Cre is expressed in and mediates allelic recombination of oncogenic genes in ovarian surface epithelial cells. That KrasG12D/Pten mutant granulosa cells do not transform but rather undergo cell cycle arrest indicates that they resist the oncogenic insults of Kras/Pten by robust self-protecting mechanisms that silence the Kras gene and elevate PTEN and phosphorylated p38 MAPK.

  19. Curcumin Promotes Cell Cycle Arrest and Inhibits Survival of Human Renal Cancer Cells by Negative Modulation of the PI3K/AKT Signaling Pathway.

    PubMed

    Zhang, Hao; Xu, Weili; Li, Baolin; Zhang, Kai; Wu, Yudong; Xu, Haidong; Wang, Junyong; Zhang, Jun; Fan, Rui; Wei, Jinxing

    2015-12-01

    Curcumin possesses anti-cancer effects. In the current study, we tested the effect of curcumin on cell proliferation, viability, apoptosis, cell cycle phases, and activation of the PI3K/Akt pathway in the renal cell carcinoma (RCC) cell line RCC-949. We observed that cell proliferation and viability were markedly inhibited by curcumin, while cell apoptosis was promoted. The latter effect was associated with increased expression of Bcl-2 and diminished expression of Bax (both: mRNA and protein). The cells treated with curcumin increasingly went into cell cycle arrest, which was likely mediated by diminished expression of cyclin B1, as seen in curcumin-treated cells. In addition, curcumin decreased activation of the PI3K/AKT signaling pathway. In conclusion, our results demonstrate that curcumin exerts anti-cancer effects by negative modulation of the PI3K/AKT signaling pathway and may represent a promising new drug to treat RCC. PMID:27259310

  20. Sulforaphane, a Dietary Isothiocyanate, Induces G2/M Arrest in Cervical Cancer Cells through CyclinB1 Downregulation and GADD45β/CDC2 Association

    PubMed Central

    Cheng, Ya-Min; Tsai, Ching-Chou; Hsu, Yi-Chiang

    2016-01-01

    Globally, cervical cancer is the most common malignancy affecting women. The main treatment methods for this type of cancer include conization or hysterectomy procedures. Sulforaphane (SFN) is a natural, compound-based drug derived from dietary isothiocyanates which has previously been shown to possess potent anti-tumor and chemopreventive effects against several types of cancer. The present study investigated the effects of SFN on anti-proliferation and G2/M phase cell cycle arrest in cervical cancer cell lines (Cx, CxWJ, and HeLa). We found that cytotoxicity is associated with an accumulation of cells in the G2/M phases of the cell-cycle. Treatment with SFN led to cell cycle arrest as well as the down-regulation of Cyclin B1 expression, but not of CDC2 expression. In addition, the effects of GADD45β gene activation in cell cycle arrest increase proportionally with the dose of SFN; however, mitotic delay and the inhibition of proliferation both depend on the dosage of SFN used to treat cancer cells. These results indicate that SFN may delay the development of cancer by arresting cell growth in the G2/M phase via down-regulation of Cyclin B1 gene expression, dissociation of the cyclin B1/CDC2 complex, and up-regulation of GADD45β proteins. PMID:27626412

  1. Interleukin-1beta can mediate growth arrest and differentiation via the leukemia inhibitory factor/JAK/STAT pathway in medullary thyroid carcinoma cells.

    PubMed

    Park, Jong-In; Strock, Christopher J; Ball, Douglas W; Nelkin, Barry D

    2005-02-01

    Interleukin-1beta (IL-1beta) is a pleiotropic cytokine that can induce several cellular signal transduction pathways. Here, we show that IL-1beta can induce cell cycle arrest and differentiation in the human medullary thyroid carcinoma (MTC) cell line, TT. IL-1beta induces cell cycle arrest accompanied by morphological changes and expression of the neuroendocrine marker calcitonin. These changes are blocked by the MEK1/2 specific inhibitor U0126, indicating that MEK1/2 is essential for IL-1beta signaling in TT cells. IL-1beta induces expression of leukemia inhibitory factor (LIF) and activation of STAT3 via the MEK/ERK pathway. This activation of STAT3 could be abrogated by treatment with anti-LIF neutralizing antibody or anti-gp130 blocking antibody, indicating that induction of LIF expression is sufficient and essential for STAT3 activation by IL-1beta. In addition to activation of the LIF/JAK/STAT pathway, IL-1beta also induced an MEK/ERK-mediated intracellular cell-autonomous signaling pathway that is independently sufficient for growth arrest and differentiation. Thus, IL-1beta activates the MEK/ERK pathway to induce growth arrest and differentiation in MTC cells via dual independent signaling mechanisms, the cell-extrinsic LIF/JAK/STAT pathway, and the cell-intrinsic autonomous signaling pathway.

  2. Sulforaphane, a Dietary Isothiocyanate, Induces G₂/M Arrest in Cervical Cancer Cells through CyclinB1 Downregulation and GADD45β/CDC2 Association.

    PubMed

    Cheng, Ya-Min; Tsai, Ching-Chou; Hsu, Yi-Chiang

    2016-01-01

    Globally, cervical cancer is the most common malignancy affecting women. The main treatment methods for this type of cancer include conization or hysterectomy procedures. Sulforaphane (SFN) is a natural, compound-based drug derived from dietary isothiocyanates which has previously been shown to possess potent anti-tumor and chemopreventive effects against several types of cancer. The present study investigated the effects of SFN on anti-proliferation and G₂/M phase cell cycle arrest in cervical cancer cell lines (Cx, CxWJ, and HeLa). We found that cytotoxicity is associated with an accumulation of cells in the G₂/M phases of the cell-cycle. Treatment with SFN led to cell cycle arrest as well as the down-regulation of Cyclin B1 expression, but not of CDC2 expression. In addition, the effects of GADD45β gene activation in cell cycle arrest increase proportionally with the dose of SFN; however, mitotic delay and the inhibition of proliferation both depend on the dosage of SFN used to treat cancer cells. These results indicate that SFN may delay the development of cancer by arresting cell growth in the G₂/M phase via down-regulation of Cyclin B1 gene expression, dissociation of the cyclin B1/CDC2 complex, and up-regulation of GADD45β proteins. PMID:27626412

  3. Effects of DNA double-strand and single-strand breaks on intrachromosomal recombination events in cell-cycle-arrested yeast cells.

    PubMed Central

    Galli, A; Schiestl, R H

    1998-01-01

    Intrachromosomal recombination between repeated elements can result in deletion (DEL recombination) events. We investigated the inducibility of such intrachromosomal recombination events at different stages of the cell cycle and the nature of the primary DNA lesions capable of initiating these events. Two genetic systems were constructed in Saccharomyces cerevisiae that select for DEL recombination events between duplicated alleles of CDC28 and TUB2. We determined effects of double-strand breaks (DSBs) and single-strand breaks (SSBs) between the duplicated alleles on DEL recombination when induced in dividing cells or cells arrested in G1 or G2. Site-specific DSBs and SSBs were produced by overexpression of the I-Sce I endonuclease and the gene II protein (gIIp), respectively. I-Sce I-induced DSBs caused an increase in DEL recombination frequencies in both dividing and cell-cycle-arrested cells, indicating that G1- and G2-arrested cells are capable of completing DSB repair. In contrast, gIIp-induced SSBs caused an increase in DEL recombination frequency only in dividing cells. To further examine these phenomena we used both gamma-irradiation, inducing DSBs as its most relevant lesion, and UV, inducing other forms of DNA damage. UV irradiation did not increase DEL recombination frequencies in G1 or G2, whereas gamma-rays increased DEL recombination frequencies in both phases. Both forms of radiation, however, induced DEL recombination in dividing cells. The results suggest that DSBs but not SSBs induce DEL recombination, probably via the single-strand annealing pathway. Further, DSBs in dividing cells may result from the replication of a UV or SSB-damaged template. Alternatively, UV induced events may occur by replication slippage after DNA polymerase pausing in front of the damage. PMID:9649517

  4. Quercetin, a Natural Flavonoid Interacts with DNA, Arrests Cell Cycle and Causes Tumor Regression by Activating Mitochondrial Pathway of Apoptosis

    PubMed Central

    Srivastava, Shikha; Somasagara, Ranganatha R.; Hegde, Mahesh; Nishana, Mayilaadumveettil; Tadi, Satish Kumar; Srivastava, Mrinal; Choudhary, Bibha; Raghavan, Sathees C.

    2016-01-01

    Naturally occurring compounds are considered as attractive candidates for cancer treatment and prevention. Quercetin and ellagic acid are naturally occurring flavonoids abundantly seen in several fruits and vegetables. In the present study, we evaluate and compare antitumor efficacies of quercetin and ellagic acid in animal models and cancer cell lines in a comprehensive manner. We found that quercetin induced cytotoxicity in leukemic cells in a dose-dependent manner, while ellagic acid showed only limited toxicity. Besides leukemic cells, quercetin also induced cytotoxicity in breast cancer cells, however, its effect on normal cells was limited or none. Further, quercetin caused S phase arrest during cell cycle progression in tested cancer cells. Quercetin induced tumor regression in mice at a concentration 3-fold lower than ellagic acid. Importantly, administration of quercetin lead to ~5 fold increase in the life span in tumor bearing mice compared to that of untreated controls. Further, we found that quercetin interacts with DNA directly, and could be one of the mechanisms for inducing apoptosis in both, cancer cell lines and tumor tissues by activating the intrinsic pathway. Thus, our data suggests that quercetin can be further explored for its potential to be used in cancer therapeutics and combination therapy. PMID:27068577

  5. Quercetin, a Natural Flavonoid Interacts with DNA, Arrests Cell Cycle and Causes Tumor Regression by Activating Mitochondrial Pathway of Apoptosis.

    PubMed

    Srivastava, Shikha; Somasagara, Ranganatha R; Hegde, Mahesh; Nishana, Mayilaadumveettil; Tadi, Satish Kumar; Srivastava, Mrinal; Choudhary, Bibha; Raghavan, Sathees C

    2016-01-01

    Naturally occurring compounds are considered as attractive candidates for cancer treatment and prevention. Quercetin and ellagic acid are naturally occurring flavonoids abundantly seen in several fruits and vegetables. In the present study, we evaluate and compare antitumor efficacies of quercetin and ellagic acid in animal models and cancer cell lines in a comprehensive manner. We found that quercetin induced cytotoxicity in leukemic cells in a dose-dependent manner, while ellagic acid showed only limited toxicity. Besides leukemic cells, quercetin also induced cytotoxicity in breast cancer cells, however, its effect on normal cells was limited or none. Further, quercetin caused S phase arrest during cell cycle progression in tested cancer cells. Quercetin induced tumor regression in mice at a concentration 3-fold lower than ellagic acid. Importantly, administration of quercetin lead to ~5 fold increase in the life span in tumor bearing mice compared to that of untreated controls. Further, we found that quercetin interacts with DNA directly, and could be one of the mechanisms for inducing apoptosis in both, cancer cell lines and tumor tissues by activating the intrinsic pathway. Thus, our data suggests that quercetin can be further explored for its potential to be used in cancer therapeutics and combination therapy. PMID:27068577

  6. Constitutively active Notch1 induces growth arrest of HPV-positive cervical cancer cells via separate signaling pathways

    SciTech Connect

    Talora, Claudio; Cialfi, Samantha; Segatto, Oreste; Morrone, Stefania; Kim Choi, John; Frati, Luigi; Paolo Dotto, Gian; Gulino, Alberto; Screpanti, Isabella . E-mail: isabella.screpanti@uniroma1.it

    2005-05-01

    Notch signaling plays a key role in cell-fate determination and differentiation in different organisms and cell types. Several reports suggest that Notch signaling may be involved in neoplastic transformation. However, in primary keratinocytes, Notch1 can function as a tumor suppressor. Similarly, in HPV-positive cervical cancer cells, constitutively active Notch1 signaling was found to cause growth suppression. Activated Notch1 in these cells represses viral E6/E7 expression through AP-1 down-modulation, resulting in increased p53 expression and a block of pRb hyperphosphorylation. Here we show that in cervical cancer cell lines in which Notch1 ability to repress AP-1 activity is impaired, Notch1-enforced expression elicits an alternative pathway leading to growth arrest. Indeed, activated Notch1 signaling suppresses activity of the helix-loop-helix transcription factor E47, via ERK1/2 activation, resulting in inhibition of cell cycle progression. Moreover, we found that RBP-J{kappa}-dependent Notch signaling is specifically repressed in cervical cancer cells and this repression could provide one such mechanism that needs to be activated for cervical carcinogenesis. Finally, we show that inhibition of endogenous Notch1 signaling, although results in a proliferative advantage, sensitizes cervical cancer cell lines to drug-induced apoptosis. Together, our results provide novel molecular insights into Notch1-dependent growth inhibitory effects, counteracting the transforming potential of HPV.

  7. A multimodality imaging model to track viable breast cancer cells from single arrest to metastasis in the mouse brain

    PubMed Central

    Parkins, Katie M.; Hamilton, Amanda M.; Makela, Ashley V.; Chen, Yuanxin; Foster, Paula J.; Ronald, John A.

    2016-01-01

    Cellular MRI involves sensitive visualization of iron-labeled cells in vivo but cannot differentiate between dead and viable cells. Bioluminescence imaging (BLI) measures cellular viability, and thus we explored combining these tools to provide a more holistic view of metastatic cancer cell fate in mice. Human breast carcinoma cells stably expressing Firefly luciferase were loaded with iron particles, injected into the left ventricle, and BLI and MRI were performed on days 0, 8, 21 and 28. The number of brain MR signal voids (i.e., iron-loaded cells) on day 0 significantly correlated with BLI signal. Both BLI and MRI signals decreased from day 0 to day 8, indicating a loss of viable cells rather than a loss of iron label. Total brain MR tumour volume on day 28 also correlated with BLI signal. Overall, BLI complemented our sensitive cellular MRI technologies well, allowing us for the first time to screen animals for successful injections, and, in addition to MR measures of cell arrest and tumor burden, provided longitudinal measures of cancer cell viability in individual animals. We predict this novel multimodality molecular imaging framework will be useful for evaluating the efficacy of emerging anti-cancer drugs at different stages of the metastatic cascade. PMID:27767185

  8. Prognostic value of cell-free plasma DNA in patients with cardiac arrest outside the hospital: an observational cohort study

    PubMed Central

    2010-01-01

    Introduction Many approaches have been examined to try to predict patient outcome after cardiopulmonary resuscitation. It has been shown that plasma DNA could predict mortality in critically ill patients but no data are available regarding its clinical value in patients after out-of-hospital cardiac arrest. In this study we investigated whether plasma DNA on arrival at the emergency room may be useful in predicting the outcome of these patients. Methods We performed a prospective study of out-of-hospital patients with cardiac arrest who achieved return of spontaneous circulation after successful resuscitation. Cardiovascular co-morbidities and resuscitation history were recorded according to the Utstein Style. The outcome measures were 24 h and overall in-hospital mortality. Cell-free plasma DNA was measured by real-time quantitative PCR assay for the β-globin gene in blood samples drawn within two hours after the arrest. Descriptive statistics, multiple logistic regression analysis, and receiver operator characteristic (ROC) curves were calculated. Results Eighty-five consecutive patients were analyzed with a median time to return of spontaneous circulation of 27 minutes (interquartile range (IQR) 18 to 35). Thirty patients died within 24 h and 58 died during the hospital course. Plasma DNA concentrations at admission were higher in non-survivors at 24 h than in survivors (median 5,520 genome equivalents (GE)/ml, vs 2810 GE/ml, P < 0.01), and were also higher in patients who died in the hospital than in survivors to discharge (median 4,150 GE/ml vs 2,460 GE/ml, P < 0.01). Lactate clearance at six hours was significantly higher in 24 h survivors (P < 0.05). The area under the ROC curves for plasma DNA to predict 24-hour mortality and in-hospital mortality were 0.796 (95% confidence interval (CI) 0.701 to 0.890) and 0.652 (95% CI 0.533 to 0.770). The best cut-off value of plasma DNA for 24-h mortality was 4,340 GE/ml (sensitivity 76%, specificity 83%), and for in

  9. Tristetraprolin induces cell cycle arrest in breast tumor cells through targeting AP-1/c-Jun and NF-κB pathway.

    PubMed

    Xu, Li; Ning, Huan; Gu, Ling; Wang, Qinghong; Lu, Wenbao; Peng, Hui; Cui, Weiguang; Ying, Baoling; Ross, Christina R; Wilson, Gerald M; Wei, Lin; Wold, William S M; Liu, Jianguo

    2015-12-01

    The main characteristic of cancers, including breast cancer, is the ability of cancer cells to proliferate uncontrollably. However, the underlying mechanisms of cancer cell proliferation, especially those regulated by the RNA binding protein tristetraprolin (TTP), are not completely understood. In this study, we found that TTP inhibits cell proliferation in vitro and suppresses tumor growth in vivo through inducing cell cycle arrest at the S phase. Our studies demonstrate that TTP inhibits c-Jun expression through the C-terminal Zn finger and therefore increases Wee1 expression, a regulatory molecule which controls cell cycle transition from the S to the G2 phase. In contrast to the well-known function of TTP in regulating mRNA stability, TTP inhibits c-Jun expression at the level of transcription by selectively blocking NF-κB p65 nuclear translocation. Reconstitution of NF-κB p65 completely abolishes the inhibition of c-Jun transcription by TTP. Moreover, reconstitution of c-Jun in TTP-expressing breast tumor cells diminishes Wee1 overexpression and promotes cell proliferation. Our results indicate that TTP suppresses c-Jun expression that results in Wee1 induction which causes cell cycle arrest at the S phase and inhibition of cell proliferation. Our study provides a new pathway for TTP function as a tumor suppressor which could be targeted in tumor treatment. PMID:26497679

  10. Tristetraprolin induces cell cycle arrest in breast tumor cells through targeting AP-1/c-Jun and NF-κB pathway

    PubMed Central

    Gu, Ling; Wang, Qinghong; Lu, Wenbao; Peng, Hui; Cui, Weiguang; Ying, Baoling; Ross, Christina R.; Wilson, Gerald M.; Wei, Lin; Wold, William S.M.; Liu, Jianguo

    2015-01-01

    The main characteristic of cancers, including breast cancer, is the ability of cancer cells to proliferate uncontrollably. However, the underlying mechanisms of cancer cell proliferation, especially those regulated by the RNA binding protein tristetraprolin (TTP), are not completely understood. In this study, we found that TTP inhibits cell proliferation in vitro and suppresses tumor growth in vivo through inducing cell cycle arrest at the S phase. Our studies demonstrate that TTP inhibits c-Jun expression through the C-terminal Zn finger and therefore increases Wee1 expression, a regulatory molecule which controls cell cycle transition from the S to the G2 phase. In contrast to the well-known function of TTP in regulating mRNA stability, TTP inhibits c-Jun expression at the level of transcription by selectively blocking NF-κB p65 nuclear translocation. Reconstitution of NF-κB p65 completely abolishes the inhibition of c-Jun transcription by TTP. Moreover, reconstitution of c-Jun in TTP-expressing breast tumor cells diminishes Wee1 overexpression and promotes cell proliferation. Our results indicate that TTP suppresses c-Jun expression that results in Wee1 induction which causes cell cycle arrest at the S phase and inhibition of cell proliferation. Our study provides a new pathway for TTP function as a tumor suppressor which could be targeted in tumor treatment. PMID:26497679

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

    SciTech Connect

    Lee, Kyung-Mi; Yun, Ji Ho; Lee, Dong Hwa; Park, Young Gyun; Son, Kun Ho; Nho, Chu Won; Kim, Yeong Shik

    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.

  12. Arctigenin induces cell cycle arrest by blocking the phosphorylation of Rb via the modulation of cell cycle regulatory proteins in human gastric cancer cells.

    PubMed

    Jeong, Jin Boo; Hong, Se Chul; Jeong, Hyung Jin; Koo, Jin Suk

    2011-10-01

    Gastric cancer is a leading cause of cancer-related deaths, worldwide being second only to lung cancer as a cause of death. Arctigenin, a representative dibenzylbutyrolactone lignan, occurs in a variety of plants. However, the molecular mechanisms of arctigenin for anti-tumor effect on gastric cancer have not been examined. This study examined the biological effects of arctigenin on the human gastric cancer cell line SNU-1 and AGS. Cell proliferation was determined by MTT assay. In MTT assay, the proliferation of SNU-1 and AGS cells was significantly inhibited by arctigenin in a time and dose dependent manner, as compared with SNU-1 and AGS cells cultured in the absence of arctigenin. Inhibition of cell proliferation by arctigenin was in part associated with apoptotic cell death, as shown by changes in the expression ratio of Bcl-2 to Bax by arctigenin. Also, arctigenin blocked cell cycle arrest from G(1) to S phase by regulating the expression of cell cycle regulatory proteins such as Rb, cyclin D1, cyclin E, CDK4, CDK2, p21Waf1/Cip1 and p15 INK4b. The antiproliferative effect of arctigenin on SNU-1 and AGS gastric cancer cells revealed in this study suggests that arctigenin has intriguing potential as a chemopreventive or chemotherapeutic agent.

  13. Bone marrow mesenchymal stromal cells affect the cell cycle arrest effect of genotoxic agents on acute lymphocytic leukemia cells via p21 down-regulation.

    PubMed

    Zhang, Yiran; Hu, Kaimin; Hu, Yongxian; Liu, Lizhen; Wang, Binsheng; Huang, He

    2014-09-01

    The effect of bone marrow microenvironment on the cell cycle of acute lymphocytic leukemia (ALL) and the underlying mechanism has not been elucidated. In this study, we found that in normal condition, bone marrow mesenchymal stromal cells (BM-MSCs) had no significant effect on the cell cycle and apoptosis of ALL; in the condition when the cell cycle of ALL was blocked by genotoxic agents, BM-MSCs could increase the S-phase cell ratio and decrease the G2/M phase ratio of ALL. Besides, BM-MSCs could protect ALL cells from drug-induced apoptosis. Then, we proved that BM-MSCs affect the cell cycle arrest effect of genotoxic agents on ALL cells via p21 down-regulation. Moreover, our results indicated that activation of Wnt/β-catenin and Erk pathways might be involved in the BM-MSC-induced down-regulation of p21 in ALL cells. Targeting microenvironment-related signaling pathway may therefore be a potential novel approach for ALL therapy.

  14. Silencing of miR-124 induces neuroblastoma SK-N-SH cell differentiation, cell cycle arrest and apoptosis through promoting AHR.

    PubMed

    Huang, Tsui-Chin; Chang, Hsin-Yi; Chen, Cheng-Yu; Wu, Pei-Yi; Lee, Hsinyu; Liao, Yung-Feng; Hsu, Wen-Ming; Huang, Hsuan-Cheng; Juan, Hsueh-Fen

    2011-11-16

    Neuroblastoma is the most common extracranial solid tumor in children. We investigate whether miR-124, the abundant neuronal miRNA, plays a pivotal role in neuroblastoma. Knockdown of miR-124 promotes neuroblastoma SK-N-SH cell differentiation, cell cycle arrest and apoptosis. Further miR-124 is predicted to target aryl hydrocarbon receptor (AHR) which may promote neuroblastoma cell differentiation. We validate that miR-124 may suppress the expression of AHR by targeting its 3'-UTR. These results suggest that miR-124 could serve as a potential therapeutic target of neuroblastoma.

  15. The 20-hydroxyecdysone-induced signalling pathway in G2/M arrest of Plodia interpunctella imaginal wing cells.

    PubMed

    Siaussat, David; Bozzolan, Françoise; Porcheron, Patrick; Debernard, Stéphane

    2008-05-01

    The mechanisms involved in the control of cellular proliferation by the steroid hormone 20-hydroxyecdysone (20E) in insects are not known. We dissected the 20E signalling pathway responsible for G2/M arrest of imaginal cells from the IAL-PID2 cells of the Indian meal moth Plodia interpunctella. We first used a 5'-3' RACE-based strategy to clone a 4479bp cDNA encoding a putative P. interpunctella HR3 transcription factor named PiHR3. The deduced amino acid sequence of PiHR3 was highly similar to those of HR3 proteins from other lepidopterans, e.g. Manduca sexta and Bombyx mori. Using double-stranded RNA-mediated interference (dsRNAi), we then succeeded in blocking the ability of 20E to induce the expression of PiEcR-B1, PiUSP-2 and PiHR3 genes that encode the P. interpunctella ecdysone receptor B1-isoform, Ultraspiracle-2 isoform, the insect homologue of the vertebrate retinoid X receptor, and the HR3 transcription factor. We showed that inhibiting the 20E induction of PiEcR-B1, PiUSP-2 and PiHR3 mRNAs prevented the decreased expression of B cyclin and consequently the G2/M arrest of IAL-PID2 cells. Using this functional approach, we revealed the participation of EcR, USP and HR3 in a 20E signalling pathway that controls the proliferation of imaginal cells by regulating the expression of B cyclin.

  16. Che-1 modulates the decision between cell cycle arrest and apoptosis by its binding to p53.

    PubMed

    Desantis, A; Bruno, T; Catena, V; De Nicola, F; Goeman, F; Iezzi, S; Sorino, C; Gentileschi, M P; Germoni, S; Monteleone, V; Pellegrino, M; Kann, M; De Meo, P D; Pallocca, M; Höpker, K; Moretti, F; Mattei, E; Reinhardt, H C; Floridi, A; Passananti, C; Benzing, T; Blandino, G; Fanciulli, M

    2015-01-01

    The tumor suppressor p53 is mainly involved in the transcriptional regulation of a large number of growth-arrest- and apoptosis-related genes. However, a clear understanding of which factor/s influences the choice between these two opposing p53-dependent outcomes remains largely elusive. We have previously described that in response to DNA damage, the RNA polymerase II-binding protein Che-1/AATF transcriptionally activates p53. Here, we show that Che-1 binds directly to p53. This interaction essentially occurs in the first hours of DNA damage, whereas it is lost when cells undergo apoptosis in response to posttranscriptional modifications. Moreover, Che-1 sits in a ternary complex with p53 and the oncosuppressor Brca1. Accordingly, our analysis of genome-wide chromatin occupancy by p53 revealed that p53/Che1 interaction results in preferential transactivation of growth arrest p53 target genes over its pro-apoptotic target genes. Notably, exposure of Che-1(+/-) mice to ionizing radiations resulted in enhanced apoptosis of thymocytes, compared with WT mice. These results confirm Che-1 as an important regulator of p53 activity and suggest Che-1 to be a promising yet attractive drug target for cancer therapy. PMID:25996291

  17. Che-1 modulates the decision between cell cycle arrest and apoptosis by its binding to p53

    PubMed Central

    Desantis, A; Bruno, T; Catena, V; De Nicola, F; Goeman, F; Iezzi, S; Sorino, C; Gentileschi, M P; Germoni, S; Monteleone, V; Pellegrino, M; Kann, M; De Meo, P D; Pallocca, M; Höpker, K; Moretti, F; Mattei, E; Reinhardt, H C; Floridi, A; Passananti, C; Benzing, T; Blandino, G; Fanciulli, M

    2015-01-01

    The tumor suppressor p53 is mainly involved in the transcriptional regulation of a large number of growth-arrest- and apoptosis-related genes. However, a clear understanding of which factor/s influences the choice between these two opposing p53-dependent outcomes remains largely elusive. We have previously described that in response to DNA damage, the RNA polymerase II-binding protein Che-1/AATF transcriptionally activates p53. Here, we show that Che-1 binds directly to p53. This interaction essentially occurs in the first hours of DNA damage, whereas it is lost when cells undergo apoptosis in response to posttranscriptional modifications. Moreover, Che-1 sits in a ternary complex with p53 and the oncosuppressor Brca1. Accordingly, our analysis of genome-wide chromatin occupancy by p53 revealed that p53/Che1 interaction results in preferential transactivation of growth arrest p53 target genes over its pro-apoptotic target genes. Notably, exposure of Che-1+/− mice to ionizing radiations resulted in enhanced apoptosis of thymocytes, compared with WT mice. These results confirm Che-1 as an important regulator of p53 activity and suggest Che-1 to be a promising yet attractive drug target for cancer therapy. PMID:25996291

  18. 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

    SciTech Connect

    Gao Jiayu; Morgan, Winston A.; Sanchez-Medina, Alberto; Corcoran, Olivia

    2011-08-01

    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 G{sub 0}/G{sub 1} 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.

  19. Inhibition of root growth by narciclasine is caused by DNA damage-induced cell cycle arrest in lettuce seedlings.

    PubMed

    Hu, Yanfeng; Li, Jiaolong; Yang, Lijing; Nan, Wenbin; Cao, Xiaoping; Bi, Yurong

    2014-09-01

    Narciclasine (NCS) is an Amaryllidaceae alkaloid isolated from Narcissus tazetta bulbs. Its phytotoxic effects on plant growth were examined in lettuce (Lactuca sativa L.) seedlings. Results showed that high concentrations (0.5-5 μM) of NCS restricted the growth of lettuce roots in a dose-dependent manner. In NCS-treated lettuce seedlings, the following changes were detected: reduction of mitotic cells and cell elongation in the mature region, inhibition of proliferation of meristematic cells, and cell cycle. Moreover, comet assay and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay indicated that higher levels NCS (0.5-5 μM) induced DNA damage in root cells of lettuce. The decrease in meristematic cells and increase in DNA damage signals in lettuce roots in responses to NCS are in a dose-dependent manner. NCS-induced reactive oxygen species accumulation may explain an increase in DNA damage in lettuce roots. Thus, the restraint of root growth is due to cell cycle arrest which is caused by NCS-induced DNA damage. In addition, it was also found that NCS (0.5-5 μM) inhibited the root hair development of lettuce seedlings. Further investigations on the underlying mechanism revealed that both auxin and ethylene signaling pathways are involved in the response of root hairs to NCS. PMID:24482192

  20. Long Term Aggresome Accumulation Leads to DNA Damage, p53-dependent Cell Cycle Arrest, and Steric Interference in Mitosis.

    PubMed

    Lu, Meng; Boschetti, Chiara; Tunnacliffe, Alan

    2015-11-13

    Juxtanuclear aggresomes form in cells when levels of aggregation-prone proteins exceed the capacity of the proteasome to degrade them. It is widely believed that aggresomes have a protective function, sequestering potentially damaging aggregates until these can be removed by autophagy. However, most in-cell studies have been carried out over a few days at most, and there is little information on the long term effects of aggresomes. To examine these long term effects, we created inducible, single-copy cell lines that expressed aggregation-prone polyglutamine proteins over several months. We present evidence that, as perinuclear aggresomes accumulate, they are associated with abnormal nuclear morphology and DNA double-strand breaks, resulting in cell cycle arrest via the phosphorylated p53 (Ser-15)-dependent pathway. Further analysis reveals that aggresomes can have a detrimental effect on mitosis by steric interference with chromosome alignment, centrosome positioning, and spindle formation. The incidence of apoptosis also increased in aggresome-containing cells. These severe defects developed gradually after juxtanuclear aggresome formation and were not associated with small cytoplasmic aggregates alone. Thus, our findings demonstrate that, in dividing cells, aggresomes are detrimental over the long term, rather than protective. This suggests a novel mechanism for polyglutamine-associated developmental and cell biological abnormalities, particularly those with early onset and non-neuronal pathologies.

  1. Inhibition of root growth by narciclasine is caused by DNA damage-induced cell cycle arrest in lettuce seedlings.

    PubMed

    Hu, Yanfeng; Li, Jiaolong; Yang, Lijing; Nan, Wenbin; Cao, Xiaoping; Bi, Yurong

    2014-09-01

    Narciclasine (NCS) is an Amaryllidaceae alkaloid isolated from Narcissus tazetta bulbs. Its phytotoxic effects on plant growth were examined in lettuce (Lactuca sativa L.) seedlings. Results showed that high concentrations (0.5-5 μM) of NCS restricted the growth of lettuce roots in a dose-dependent manner. In NCS-treated lettuce seedlings, the following changes were detected: reduction of mitotic cells and cell elongation in the mature region, inhibition of proliferation of meristematic cells, and cell cycle. Moreover, comet assay and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay indicated that higher levels NCS (0.5-5 μM) induced DNA damage in root cells of lettuce. The decrease in meristematic cells and increase in DNA damage signals in lettuce roots in responses to NCS are in a dose-dependent manner. NCS-induced reactive oxygen species accumulation may explain an increase in DNA damage in lettuce roots. Thus, the restraint of root growth is due to cell cycle arrest which is caused by NCS-induced DNA damage. In addition, it was also found that NCS (0.5-5 μM) inhibited the root hair development of lettuce seedlings. Further investigations on the underlying mechanism revealed that both auxin and ethylene signaling pathways are involved in the response of root hairs to NCS.

  2. Leptospermum flavescens Constituent-LF1 Causes Cell Death through the Induction of Cell Cycle Arrest and Apoptosis in Human Lung Carcinoma Cells

    PubMed Central

    Navanesan, Suerialoasan; Abdul Wahab, Norhanom; Manickam, Sugumaran; Sim, Kae Shin

    2015-01-01

    Leptospermum flavescens Sm. (Myrtaceae), locally known as ‘Senna makki’ is a smallish tree that is widespread and recorded to naturally occur in the montane regions above 900 m a.s.l from Burma to Australia. Although the species is recorded to be used traditionally to treat various ailments, there is limited data on biological and chemical investigations of L. flavescens. The aim of the present study was to investigate and understand the ability of L. flavescens in inducing cell death in lung cancer cells. The cytotoxic potentials of the extraction yields (methanol, hexane, ethyl acetate and water extracts as wells as a semi pure fraction, LF1) were evaluated against two human non-small cell lung carcinoma cell lines (A549 and NCI-H1299) using the MTT assay. LF1 showed the greatest cytotoxic effect against both cell lines with IC50 values of 7.12 ± 0.07 and 9.62 ± 0.50 μg/ml respectively. LF1 treated cells showed a sub-G1 region in the cell cycle analysis and also caused the presence of apoptotic morphologies in cells stained with acridine orange and ethidium bromide. Treatment with LF1 manifested an apoptotic population in cells that were evaluated using the Annexin V/ propidium iodide assay. Increasing dosage of LF1 caused a rise in the presence of activated caspase-3 enzymes in treated cells. Blockage of cell cycle progression was also observed in LF1-treated cells. These findings suggest that LF1 induces apoptosis and cell cycle arrest in treated lung cancer cells. Further studies are being conducted to isolate and identify the active compound as well to better understand the mechanism involved in inducing cell death. PMID:26287817

  3. Quercetin reduces cyclin D1 activity and induces G1 phase arrest in HepG2 cells

    PubMed Central

    ZHOU, JIN; LI, LU; FANG, LI; XIE, HUA; YAO, WENXIU; ZHOU, XIANG; XIONG, ZHUJUAN; WANG, LI; LI, ZHIXI; LUO, FENG

    2016-01-01

    Quercetin is able to inhibit proliferation of malignant tumor cells; however, the exact mechanism involved in this biological process remains unclear. The current study utilized a quantitative proteomic analysis to explore the antitumor mechanisms of quercetin. The leucine of HepG2 cells treated with quercetin was labeled as d3 by stable isotope labeling by amino acids in cell culture (SILAC). The isotope peaks of control HepG2 cells were compared with the d3-labeled HepG2 cells by mass spectrometry (MS) to identify significantly altered proteins. Reverse transcription-polymerase chain reaction (RT-PCR) and western blot analyses were subsequently employed to verify the results of the MS analysis. A flow cytometry assay was designed to observe the influence of various quercetin treatment concentrations on the cell cycle distribution of HepG2 cells. The results indicated that quercetin is able to substantially inhibit proliferation of HepG2 cells and induce an obvious morphological alteration of cells. According to the MS results, the 70 credibly-changed proteins that were identified may play important roles in multiple cellular processes, including protein synthesis, signaling, cytoskeletal processes and metabolism. Among these functional proteins, the expression of cyclin D1 (CCND1) was found to be significantly decreased. RT-PCR and western blot analyses verified the SILAC-MS results of decreased CCND1 expression. In summary, flow cytometry revealed that quercetin is able to induce G1 phase arrest in HepG2 cells. Based on the aforementioned observations, it is suggested that quercetin exerts antitumor activity in HepG2 cells through multiple pathways, including interfering with CCND1 gene expression to disrupt the cell cycle and proliferation of HepG2 cells. In the future, we aim to explore this effect in vivo. PMID:27347174

  4. Achyranthes aspera Root Extracts Induce Human Colon Cancer Cell (COLO-205) Death by Triggering the Mitochondrial Apoptosis Pathway and S Phase Cell Cycle Arrest

    PubMed Central

    Arora, Shagun; Tandon, Simran

    2014-01-01

    Achyranthes aspera (AA) has been used traditionally for the cure of various disorders. However, the action of root extracts of AA as anticancer agent and its cellular mechanism remain unclear. The aim was to screen the antitumor effect of ethanolic (EAA) and aqueous (AAA) root extracts on the growth of colon cancer COLO-205 cells by testing their cytotoxicity, followed by their effect on clonogenicity, migration, and induction of apoptosis. Mechanisms leading to apoptosis and cell cycle arrest were also investigated by expression studies of caspase-9, caspase-3, Bax, Bcl-2, p16, p21, and p27 genes, followed by flow cytometric analysis for cell cycle distribution. Cytotoxicity screening of AA extracts indicated greater cytotoxic activity of AAA extract against COLO-205 cells. A series of events marked by apoptosis revealed loss of cell viability, chromatin condensation, and DNA fragmentation in AAA treated cells to a greater extent. The mRNA expression levels of caspase-9, caspase-3, Bax, p16, p21, and p27 were markedly increased in the AAA treated cells, along with decreased Bcl-2 expression. The cell cycle arrest at S phase was detected by flow cytometric analysis after treatment with AAA. Overall the study signifies the aqueous extracts as a promising therapeutic candidate against cancer. PMID:25401123

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

    PubMed Central

    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

  6. Resveratrol induces cell cycle arrest in human gastric cancer MGC803 cells via the PTEN-regulated PI3K/Akt signaling pathway.

    PubMed

    Jing, Xiaoping; Cheng, Weiwei; Wang, Shiying; Li, Pin; He, Li

    2016-01-01

    Resveratrol is a polyphenolic compound that is extracted from Polygonum cuspidatum and is used in traditional Chinese medicine. Previous data have shown that resveratrol inhibits the growth of human gastric cancer. MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide] and trypan blue assays showed that resveratrol significantly decreased the survival rate of MGC803 cells in a concentration- and time-dependent manner. Our flow cytometric analysis showed that resveratrol treatment arrested the cells at the G0/G1 phase of the cell cycle. Furthermore, western blotting demonstrated that resveratrol decreased the protein expression of phospho-glycogen synthase kinase 3β (p-GSK3β), cyclin D1, phospho-phosphatase and tensin homologue (p-PTEN), phospho-phosphatidylinositol 3'-OH kinase (p-PI3K), and phospho-protein kinase B (p-PKB/Akt). We also found that resveratrol inhibited the progression of the cell cycle in MGC803 cells by repressing p-PI3K and p-Akt expression. Meanwhile, resveratrol did not decrease the phosphorylation level of Akt when the PTEN gene expression was knocked down by an siRNA in the MGC803 cells. Taken together, these results suggest that resveratrol induced cell cycle arrest in human gastric cancer MGC803 cells by regulating the PTEN/PI3K/Akt signaling pathway.

  7. Resveratrol induces cell cycle arrest in human gastric cancer MGC803 cells via the PTEN-regulated PI3K/Akt signaling pathway.

    PubMed

    Jing, Xiaoping; Cheng, Weiwei; Wang, Shiying; Li, Pin; He, Li

    2016-01-01

    Resveratrol is a polyphenolic compound that is extracted from Polygonum cuspidatum and is used in traditional Chinese medicine. Previous data have shown that resveratrol inhibits the growth of human gastric cancer. MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide] and trypan blue assays showed that resveratrol significantly decreased the survival rate of MGC803 cells in a concentration- and time-dependent manner. Our flow cytometric analysis showed that resveratrol treatment arrested the cells at the G0/G1 phase of the cell cycle. Furthermore, western blotting demonstrated that resveratrol decreased the protein expression of phospho-glycogen synthase kinase 3β (p-GSK3β), cyclin D1, phospho-phosphatase and tensin homologue (p-PTEN), phospho-phosphatidylinositol 3'-OH kinase (p-PI3K), and phospho-protein kinase B (p-PKB/Akt). We also found that resveratrol inhibited the progression of the cell cycle in MGC803 cells by repressing p-PI3K and p-Akt expression. Meanwhile, resveratrol did not decrease the phosphorylation level of Akt when the PTEN gene expression was knocked down by an siRNA in the MGC803 cells. Taken together, these results suggest that resveratrol induced cell cycle arrest in human gastric cancer MGC803 cells by regulating the PTEN/PI3K/Akt signaling pathway. PMID:26530632

  8. Tumor suppressor protein Lgl mediates G1 cell cycle arrest at high cell density by forming an Lgl-VprBP-DDB1 complex

    PubMed Central

    Yamashita, Kazunari; Ide, Mariko; Furukawa, Kana T.; Suzuki, Atsushi; Hirano, Hisashi; Ohno, Shigeo

    2015-01-01

    Lethal giant larvae (Lgl) is an evolutionarily conserved tumor suppressor whose loss of function causes disrupted epithelial architecture with enhanced cell proliferation and defects in cell polarity. A role for Lgl in the establishment and maintenance of cell polarity via suppression of the PAR-aPKC polarity complex is established; however, the mechanism by which Lgl regulates cell proliferation is not fully understood. Here we show that depletion of Lgl1 and Lgl2 in MDCK epithelial cells results in overproliferation and overproduction of Lgl2 causes G1 arrest. We also show that Lgl associates with the VprBP-DDB1 complex independently of the PAR-aPKC complex and prevents the VprBP-DDB1 subunits from binding to Cul4A, a central component of the CRL4 [VprBP] ubiquitin E3 ligase complex implicated in G1- to S-phase progression. Consistently, depletion of VprBP or Cul4 rescues the overproliferation of Lgl-depleted cells. In addition, the affinity between Lgl2 and the VprBP-DDB1 complex increases at high cell density. Further, aPKC-mediated phosphorylation of Lgl2 negatively regulates the interaction between Lgl2 and VprBP-DDB1 complex. These results suggest a mechanism protecting overproliferation of epithelial cells in which Lgl plays a critical role by inhibiting formation of the CRL4 [VprBP] complex, resulting in G1 arrest. PMID:25947136

  9. Glehnia littoralis Root Extract Induces G0/G1 Phase Cell Cycle Arrest in the MCF-7 Human Breast Cancer Cell Line.

    PubMed

    de la Cruz, Joseph Flores; Vergara, Emil Joseph Sanvictores; Cho, Yura; Hong, Hee Ok; Oyungerel, Baatartsogt; Hwang, Seong Gu

    2015-01-01

    Glehnia littoralis (GL) is widely used as an oriental medicine for cough, fever, stroke and other disease conditions. However, the anti-cancer properties of GL on MCF-7 human breast cancer cells have not been investigated. In order to elucidate anti-cancer properties and underlying cell death mechanisms, MCF-7cells (5 X 104/well) were treated with Glehnia littoralis root extract at 0-400 ug/ml. A hot water extract of GL root inhibited the proliferation of MCF-7 cells in a dose-dependent manner. Analysis of the cell cycle after treatment of MCF-7 cells with increasing concentrations of GL root extract for 24 hours showed significant cell cycle arrest in the G1 phase. RT-PCR and Western blot analysis both revealed that GL root extract significantly increased the expression of p21 and p27 with an accompanyingdecrease in both CDK4 and cyclin D1. Our reuslts indicated that GL root extract arrested the proliferation of MCF-7 cells in G1 phase through inhibition of CDK4 and cyclin D1 via increased induction of p21 and p27. In summary, the current study showed that GL could serve as a potential source of chemotherapeutic or chemopreventative agents against human breast cancer.

  10. dbl-1/TGF-β and daf-12/NHR Signaling Mediate Cell-Nonautonomous Effects of daf-16/FOXO on Starvation-Induced Developmental Arrest.

    PubMed

    Kaplan, Rebecca E W; Chen, Yutao; Moore, Brad T; Jordan, James M; Maxwell, Colin S; Schindler, Adam J; Baugh, L Ryan

    2015-12-01

    Nutrient availability has profound influence on development. In the nematode C. elegans, nutrient availability governs post-embryonic development. L1-stage larvae remain in a state of developmental arrest after hatching until they feed. This "L1 arrest" (or "L1 diapause") is associated with increased stress resistance, supporting starvation survival. Loss of the transcription factor daf-16/FOXO, an effector of insulin/IGF signaling, results in arrest-defective and starvation-sensitive phenotypes. We show that daf-16/FOXO regulates L1 arrest cell-nonautonomously, suggesting that insulin/IGF signaling regulates at least one additional signaling pathway. We used mRNA-seq to identify candidate signaling molecules affected by daf-16/FOXO during L1 arrest. dbl-1/TGF-β, a ligand for the Sma/Mab pathway, daf-12/NHR and daf-36/oxygenase, an upstream component of the daf-12 steroid hormone signaling pathway, were up-regulated during L1 arrest in a daf-16/FOXO mutant. Using genetic epistasis analysis, we show that dbl-1/TGF-β and daf-12/NHR steroid hormone signaling pathways are required for the daf-16/FOXO arrest-defective phenotype, suggesting that daf-16/FOXO represses dbl-1/TGF-β, daf-12/NHR and daf-36/oxygenase. The dbl-1/TGF-β and daf-12/NHR pathways have not previously been shown to affect L1 development, but we found that disruption of these pathways delayed L1 development in fed larvae, consistent with these pathways promoting development in starved daf-16/FOXO mutants. Though the dbl-1/TGF-β and daf-12/NHR pathways are epistatic to daf-16/FOXO for the arrest-defective phenotype, disruption of these pathways does not suppress starvation sensitivity of daf-16/FOXO mutants. This observation uncouples starvation survival from developmental arrest, indicating that DAF-16/FOXO targets distinct effectors for each phenotype and revealing that inappropriate development during starvation does not cause the early demise of daf-16/FOXO mutants. Overall, this study shows

  11. Growth inhibitory effect of KYKZL-1 on Hep G{sub 2} cells via inhibition of AA metabolites and caspase-3 pathway and cell cycle arrest

    SciTech Connect

    Cheng, Jing; Du, Yi-Fang; Xiao, Zhi-Yi; Pan, Li-Li; Li, Wei; Huan, Lin; Gong, Zhu-Nan; Wei, Shao-Hua; Huang, Shi-Qian; Xun, Wei; Zhang, Yi; Chang, Lei-Lei; Xie, Meng-Yu; Ao, Gui-Zhen; Cai, Jie; Qiu, Ting; Wu, Hao; Sun, Ting; Xu, Guang-Lin

    2014-01-01

    KYKZL-1, a newly synthesized compound with COX/5-LOX dual inhibition, was subjected to the inhibitory activity test on Hep G{sub 2} growth. We found that KYKZL-1 inhibited the growth of Hep G{sub 2} cells via inducing apoptosis. Further studies showed that KYKZL-1 activated caspase-3 through cytochrome c release from mitochondria and down regulation of Bcl-2/Bax ratio and reduced the high level of COX-2 and 5-LOX. As shown in its anti-inflammatory effect, KYKZL-1 also exhibited inhibitory effect on the PGE{sub 2} and LTB{sub 4} production in Hep G{sub 2} cells. Accordingly, exogenous addition of PGE{sub 2} or LTB{sub 4} reversed the decreases in cell viability. In addition, KYKZL-1 caused cell cycle arrest at the S–G{sub 2} checkpoint via the activation of p21{sup CIP1} protein and down-regulation of cyclin A expression. These data indicate that the growth inhibitory effect of KYKZL-1 is associated with inhibition of AA metabolites and caspase-3 pathway and cell cycle arrest. Combined with our previous findings, KYKZL-1 exhibiting COX/5-LOX inhibition may be a promising potential agent not only for inflammation control but also for cancer prevention/therapy with an enhanced gastric safety profile. - Highlights: • KYKZL-1 is designed to exhibit COX/5-LOX dual inhibition. • KYKZL-1 resulted in apoptosis of Hep G{sub 2} cells. • KYKZL-1 activated caspase-3 through cytochrome c and bcl-2/bax ratio. • KYKZL-1 caused cell cycle arrest via modulation of p21{sup CIP1} and cyclin A level.

  12. 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

    PubMed Central

    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

  13. BRCA1 Is Required for Maintenance of Phospho-Chk1 and G2/M Arrest during DNA Cross-Link Repair in DT40 Cells

    PubMed Central

    Draga, Margarethe; Madgett, Elizabeth B.; Vandenberg, Cassandra J.; du Plessis, David; Kaufmann, Aisling; Werler, Petra; Chakraborty, Prasun; Lowndes, Noel F.

    2015-01-01

    The Fanconi anemia DNA repair pathway is pivotal for the efficient repair of DNA interstrand cross-links. Here, we show that FA-defective (Fancc−) DT40 cells arrest in G2 phase following cross-link damage and trigger apoptosis. Strikingly, cell death was reduced in Fancc− cells by additional deletion of the BRCA1 tumor suppressor, resulting in elevated clonogenic survival. Increased resistance to cross-link damage was not due to loss of toxic BRCA1-mediated homologous recombination but rather through the loss of a G2 checkpoint. This proapoptotic role also required the BRCA1-A complex member ABRAXAS (FAM175A). Finally, we show that BRCA1 promotes G2 arrest and cell death by prolonging phosphorylation of Chk1 on serine 345 after DNA damage to sustain arrest. Our data imply that DNA-induced cross-link death in cells defective in the FA pathway is dependent on the ability of BRCA1 to prolong cell cycle arrest in G2 phase. PMID:26324327

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

    PubMed

    Gascoyne, Duncan M; Spearman, Hayley; Lyne, Linden; Puliyadi, Rathi; Perez-Alcantara, Marta; Coulton, Les; Fisher, Simon E; Croucher, Peter I; Banham, Alison H

    2015-01-01

    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.

  15. Vpr Protein of Human Immunodeficiency Virus Type 1 Binds to 14-3-3 Proteins and Facilitates Complex Formation with Cdc25C: Implications for Cell Cycle Arrest

    PubMed Central

    Kino, Tomoshige; Gragerov, Alexander; Valentin, Antonio; Tsopanomihalou, Maria; Ilyina-Gragerova, Galina; Erwin-Cohen, Rebecca; Chrousos, George P.; Pavlakis, George N.

    2005-01-01

    Vpr and selected mutants were used in a Saccharomyces cerevisiae two-hybrid screen to identify cellular interactors. We found Vpr interacted with 14-3-3 proteins, a family regulating a multitude of proteins in the cell. Vpr mutant R80A, which is inactive in cell cycle arrest, did not interact with 14-3-3. 14-3-3 proteins regulate the G2/M transition by inactivating Cdc25C phosphatase via binding to the phosphorylated serine residue at position 216 of Cdc25C. 14-3-3 overexpression in human cells synergized with Vpr in the arrest of cell cycle. Vpr did not arrest efficiently cells not expressing 14-3-3σ. This indicated that a full complement of 14-3-3 proteins is necessary for optimal Vpr function on the cell cycle. Mutational analysis showed that the C-terminal portion of Vpr, known to harbor its cell cycle-arresting activity, bound directly to the C-terminal part of 14-3-3, outside of its phosphopeptide-binding pocket. Vpr expression shifted localization of the mutant Cdc25C S216A to the cytoplasm, indicating that Vpr promotes the association of 14-3-3 and Cdc25C, independently of the presence of serine 216. Immunoprecipitations of cell extracts indicated the presence of triple complexes (Vpr/14-3-3/Cdc25C). These results indicate that Vpr promotes cell cycle arrest at the G2/M phase by facilitating association of 14-3-3 and Cdc25C independently of the latter's phosphorylation status. PMID:15708996

  16. Oleanolic acid induces mitochondrial-dependent apoptosis and G0/G1 phase arrest in gallbladder cancer cells

    PubMed Central

    Li, Huai-Feng; Wang, Xu-An; Xiang, Shan-Shan; Hu, Yun-Ping; Jiang, Lin; Shu, Yi-Jun; Li, Mao-Lan; Wu, Xiang-Song; Zhang, Fei; Ye, Yuan-Yuan; Weng, Hao; Bao, Run-Fa; Cao, Yang; Lu, Wei; Dong, Qian; Liu, Ying-Bin

    2015-01-01

    Oleanolic acid (OA), a naturally occurring triterpenoid, exhibits potential antitumor activity in many tumor cell lines. Gallbladder carcinoma is the most common malignancy of the biliary tract, and is a highly aggressive tumor with an extremely poor prognosis. Unfortunately, the effects of OA on gallbladder carcinoma are unknown. In this study, we investigated the effects of OA on gallbladder cancer cells and the underlying mechanism. The results showed that OA inhibits proliferation of gallbladder cancer cells in a dose-dependent and time-dependent manner on MTT and colony formation assay. A flow cytometry assay revealed apoptosis and G0/G1 phase arrest in GBC-SD and NOZ cells. Western blot analysis and a mitochondrial membrane potential assay demonstrated that OA functions through the mitochondrial apoptosis pathway. Moreover, this drug inhibited tumor growth in nude mice carrying subcutaneous NOZ tumor xenografts. These data suggest that OA inhibits proliferation of gallbladder cancer cells by regulating apoptosis and the cell cycle process. Thus, OA may be a promising drug for adjuvant chemotherapy in gallbladder carcinoma. PMID:26109845

  17. Mitotic Stress Is an Integral Part of the Oncogene-Induced Senescence Program that Promotes Multinucleation and Cell Cycle Arrest.

    PubMed

    Dikovskaya, Dina; Cole, John J; Mason, Susan M; Nixon, Colin; Karim, Saadia A; McGarry, Lynn; Clark, William; Hewitt, Rachael N; Sammons, Morgan A; Zhu, Jiajun; Athineos, Dimitris; Leach, Joshua D G; Marchesi, Francesco; van Tuyn, John; Tait, Stephen W; Brock, Claire; Morton, Jennifer P; Wu, Hong; Berger, Shelley L; Blyth, Karen; Adams, Peter D

    2015-09-01

    Oncogene-induced senescence (OIS) is a tumor suppression mechanism that blocks cell proliferation in response to oncogenic signaling. OIS is frequently accompanied by multinucleation; however, the origin of this is unknown. Here, we show that multinucleate OIS cells originate mostly from failed mitosis. Prior to senescence, mutant H-RasV12 activation in primary human fibroblasts compromised mitosis, concordant with abnormal expression of mitotic genes functionally linked to the observed mitotic spindle and chromatin defects. Simultaneously, H-RasV12 activation enhanced survival of cells with damaged mitoses, culminating in extended mitotic arrest and aberrant exit from mitosis via mitotic slippage. ERK-dependent transcriptional upregulation of Mcl1 was, at least in part, responsible for enhanced survival and slippage of cells with mitotic defects. Importantly, mitotic slippage and oncogene signaling cooperatively induced senescence and key senescence effectors p21 and p16. In summary, activated Ras coordinately triggers mitotic disruption and enhanced cell survival to promote formation of multinucleate senescent cells. PMID:26299965

  18. Sensitization of Melanoma Cells for Death Ligand TRAIL Is Based on Cell Cycle Arrest, ROS Production, and Activation of Proapoptotic Bcl-2 Proteins.

    PubMed

    Quast, Sandra-Annika; Steinhorst, Katja; Plötz, Michael; Eberle, Jürgen

    2015-11-01

    The death ligand TRAIL (tumor necrosis factor-related apoptosis-inducing ligand) represents a promising strategy for melanoma due to significant expression of TRAIL receptor 1 in melanoma metastases and high TRAIL sensitivity through this receptor. However, prevalent and inducible resistance are limiting its clinical use. In previous work, we and others have described multiple strategies leading to TRAIL sensitization; however, the common principles of these strategies remained elusive. Here, we demonstrate in melanoma cell lines (TRAIL-sensitive, TRAIL-resistant, and TRAIL-selected cells with acquired resistance) that cell cycle arrest clearly correlates with enhanced TRAIL sensitivity. Cell cycle arrest was induced by high cell confluence, serum starvation, or cyclin-dependent kinase (CDK) 4/6 inhibition. Addressing the signaling pathways revealed disruption of mitochondrial membrane potential and production of reactive oxygen species (ROS) in response to antiproliferative conditions alone. Activation of the proapoptotic Bcl-2 protein Bax and inhibition of apoptosis by Bcl-2 overexpression or by the antioxidant N-acetyl cysteine underlined the critical involvement of mitochondrial apoptosis pathways and of ROS, respectively. Most pronounced was the upregulation of small proapoptotic Bcl-2 proteins (Puma and Bcl-xS). These data provide a general understanding on TRAIL sensitization as well as an alternative view on CDK inhibitors and may suggest selective targeting of melanoma cells by cell cycle inhibition and TRAIL.

  19. New betulinic acid derivatives induce potent and selective antiproliferative activity through cell cycle arrest at the S phase and caspase dependent apoptosis in human cancer cells.

    PubMed

    Santos, Rita C; Salvador, Jorge A R; Cortés, Roldán; Pachón, Gisela; Marín, Silvia; Cascante, Marta

    2011-06-01

    New semisynthetic derivatives of betulinic acid (BA) RS01, RS02 and RS03 with 18-45 times improved cytotoxic activity against HepG2 cells, were tested for their ability to induce apoptosis and cell cycle arrest in HepG2, HeLa and Jurkat cells. All the compounds induced significant increase in the population at the S phase more effectively than BA. RS01, RS02 and RS03 were also found to be potent inducers of apoptosis with RS01 being markedly more potent than BA, suggesting that the introduction of the imidazolyl moiety is crucial for enhancing the induction of apoptosis and the cell cycle arrest. The mechanism of apoptosis induction has been studied in HepG2 cells and found to be mediated by activation of the postmitochondrial caspases-9 and -3 cascade and possibly by mitochondrial amplification loop involving caspase-8. These facts were corroborated by detection of mitochondrial cytochrome c release and DNA fragmentation. Because RS01, RS02 and RS03 exhibited significant improved antitumor activity with respect to BA, they may be promising new agents for the treatment of cancer. In particular, RS01 is the most promising compound with an IC(50) value 45 times lower than BA on HepG2 cells and 61 times lower than the one found for the non-tumoral Chang liver cells.

  20. Photodynamic hyperthermal therapy with indocyanine green (ICG) induces apoptosis and cell cycle arrest in B16F10 murine melanoma cells.

    PubMed

    Radzi, Rozanaliza; Osaki, Tomohiro; Tsuka, Takeshi; Imagawa, Tomohiro; Minami, Saburo; Nakayama, Yuji; Okamoto, Yoshiharu

    2012-05-01

    We examined the effects of photodynamic hyperthemal therapy (PHT), which is a combination of photodynamic therapy (PDT) and hyperthermia (HT), on the apoptosis and cell cycle progression of murine melanoma B16F10 cells. The percentage of apoptotic cell was determined by flow cytometry using fluorescein isothiocyanate (FITC)-conjugated Annexin V and propidium iodide (PI) double staining. The cell cycle analysis was performed by PI staining with flow cytometry. The expression of cyclins and heat shock protein 70 (Hsp70) were examined by a Western blotting analysis. PHT induces death in B16F10 cells, and PHT-mediated apoptosis occurred acutely and persistently in vitro. Our study demonstrated that PHT using indocyanine green (ICG) and near infrared (NIR) light source induces apoptosis and G0/G1 cell cycle arrest in the B16F10 cells. PMID:22146339

  1. Photodynamic hyperthermal therapy with indocyanine green (ICG) induces apoptosis and cell cycle arrest in B16F10 murine melanoma cells.

    PubMed

    Radzi, Rozanaliza; Osaki, Tomohiro; Tsuka, Takeshi; Imagawa, Tomohiro; Minami, Saburo; Nakayama, Yuji; Okamoto, Yoshiharu

    2012-05-01

    We examined the effects of photodynamic hyperthemal therapy (PHT), which is a combination of photodynamic therapy (PDT) and hyperthermia (HT), on the apoptosis and cell cycle progression of murine melanoma B16F10 cells. The percentage of apoptotic cell was determined by flow cytometry using fluorescein isothiocyanate (FITC)-conjugated Annexin V and propidium iodide (PI) double staining. The cell cycle analysis was performed by PI staining with flow cytometry. The expression of cyclins and heat shock protein 70 (Hsp70) were examined by a Western blotting analysis. PHT induces death in B16F10 cells, and PHT-mediated apoptosis occurred acutely and