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Sample records for cycle arrest death

  1. 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

  2. Involvement of p53 in cell death following cell cycle arrest and mitotic catastrophe induced by rotenone.

    PubMed

    Gonçalves, António Pedro; Máximo, Valdemar; Lima, Jorge; Singh, Keshav K; Soares, Paula; Videira, Arnaldo

    2011-03-01

    In order to investigate the cell death-inducing effects of rotenone, a plant extract commonly used as a mitochondrial complex I inhibitor, we studied cancer cell lines with different genetic backgrounds. Rotenone inhibits cell growth through the induction of cell death and cell cycle arrest, associated with the development of mitotic catastrophe. The cell death inducer staurosporine potentiates the inhibition of cell growth by rotenone in a dose-dependent synergistic manner. The tumor suppressor p53 is involved in rotenone-induced cell death, since the drug treatment results in increased expression, phosphorylation and nuclear localization of the protein. The evaluation of the effects of rotenone on a p53-deficient cell line revealed that although not required for the promotion of mitotic catastrophe, functional p53 appears to be essential for the extensive cell death that occurs afterwards. Our results suggest that mitotic slippage also occurs subsequently to the rotenone-induced mitotic arrest and cells treated with the drug for a longer period become senescent. Treatment of mtDNA-depleted cells with rotenone induces cell death and cell cycle arrest as in cells containing wild-type mtDNA, but not formation of reactive oxygen species. This suggests that the effects of rotenone are not dependent from the production of reactive oxygen species. This work highlights the multiple effects of rotenone in cancer cells related to its action as an anti-mitotic drug.

  3. Cell cycle arrest and biochemical changes accompanying cell death in harmful dinoflagellates following exposure to bacterial algicide IRI-160AA

    PubMed Central

    Pokrzywinski, Kaytee L.; Tilney, Charles L.; Warner, Mark E.; Coyne, Kathryn J.

    2017-01-01

    Bacteria may play a role in regulating harmful algal blooms, but little is known about the biochemical and physiological changes associated with cell death induced by algicidal bacteria. Previous work characterized an algicidal exudate (IRI-160AA) produced by Shewanella sp. IRI-160 that is effective against dinoflagellates, while having little to no effect on other phytoplankton species in laboratory culture experiments. The objective of this study was to evaluate biochemical changes associated with cell death and impacts on the cell cycle in three dinoflagellate species (Prorocentrum minimum, Karlodinium veneficum and Gyrodinium instriatum) after exposure to IRI-160AA. In this study, IRI-160AA induced cell cycle arrest in all dinoflagellates examined. Several indicators for programmed cell death (PCD) that are often observed in phytoplankton in response to a variety of stressors were also evaluated. Cell death was accompanied by significant increases in DNA degradation, intra- and extracellular ROS concentrations and DEVDase (caspase-3 like) protease activity, which have been associated with PCD in other phytoplankton species. Overall, results of this investigation provide strong evidence that treatment with the bacterial algicide, IRI-160AA results in cell cycle arrest and induces biochemical changes consistent with stress-related cell death responses observed in other phytoplankton. PMID:28332589

  4. Cell cycle arrest and biochemical changes accompanying cell death in harmful dinoflagellates following exposure to bacterial algicide IRI-160AA

    NASA Astrophysics Data System (ADS)

    Pokrzywinski, Kaytee L.; Tilney, Charles L.; Warner, Mark E.; Coyne, Kathryn J.

    2017-03-01

    Bacteria may play a role in regulating harmful algal blooms, but little is known about the biochemical and physiological changes associated with cell death induced by algicidal bacteria. Previous work characterized an algicidal exudate (IRI-160AA) produced by Shewanella sp. IRI-160 that is effective against dinoflagellates, while having little to no effect on other phytoplankton species in laboratory culture experiments. The objective of this study was to evaluate biochemical changes associated with cell death and impacts on the cell cycle in three dinoflagellate species (Prorocentrum minimum, Karlodinium veneficum and Gyrodinium instriatum) after exposure to IRI-160AA. In this study, IRI-160AA induced cell cycle arrest in all dinoflagellates examined. Several indicators for programmed cell death (PCD) that are often observed in phytoplankton in response to a variety of stressors were also evaluated. Cell death was accompanied by significant increases in DNA degradation, intra- and extracellular ROS concentrations and DEVDase (caspase-3 like) protease activity, which have been associated with PCD in other phytoplankton species. Overall, results of this investigation provide strong evidence that treatment with the bacterial algicide, IRI-160AA results in cell cycle arrest and induces biochemical changes consistent with stress-related cell death responses observed in other phytoplankton.

  5. 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

  6. Bacillus thuringiensis parasporal proteins induce cell-cycle arrest and caspase-dependant apoptotic cell death in leukemic cells.

    PubMed

    Chan, Kok-Keong; Wong, Rebecca Shin-Yee; Mohamed, Shar Mariam; Ibrahim, Tengku Azmi Tengku; Abdullah, Maha; Nadarajah, Vishna Devi

    2012-01-01

    Bacillus thuringiensis (Bt) parasporal proteins with selective anticancer activity have recently garnered interest. This study determines the efficacy and mode of cell death of Bt 18 parasporal proteins against 3 leukemic cell lines (CEM-SS, CCRF-SB and CCRF-HSB-2).Cell-based biochemical analysis aimed to determine cell viability and the percentage of apoptotic cell death in treated cell lines; ultrastructural analysis to study apoptotic changes and Western blot to identify the parasporal proteins' binding site were performed. Bt 18 parasporal proteins moderately decreased viability of leukemic cells but not that of normal human T lymphocytes. Further purification of the proteins showed changes in inhibition selectivity. Phosphatidylserine externalization, active caspase-3, cell cycle, and ultrastructural analysis confirmed apoptotic activity and S-phase cell-cycle arrest. Western blot analysis demonstrated glyceraldehyde 3-phosphate dehydrogenase as a binding protein. We suggest that Bt 18 parasporal proteins inhibit leukemic cell viability by cell-cycle arrest and apoptosis and that glyceraldehyde 3-phosphate dehydrogenase binding initiates apoptosis.

  7. 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

  8. Sudden death during arrest and phencyclidine intoxication.

    PubMed

    Pestaner, Joseph P; Southall, Pamela E

    2003-06-01

    Deaths of individuals being arrested are important and complex medicolegal cases. Conclusions regarding the cause and manner of death for such cases must take into account multiple factors that may have played a role, as well as anticipate the forensic issues that will arise. In this article, we review the deaths of 2 individuals in which phencyclidine intoxication was a factor that contributed to death during arrest. Most cases of sudden death during arrest have involved cocaine intoxication; because phencyclidine's pharmacologic properties are quite different from those of cocaine, these cases allow for comparisons to those factors that may have greater importance.

  9. The novel anthraquinone derivative IMP1338 induces death of human cancer cells by p53-independent S and G2/M cell cycle arrest.

    PubMed

    Choi, Hyun Kyung; Ryu, Hwani; Son, A-Rang; Seo, Bitna; Hwang, Sang-Gu; Song, Jie-Young; Ahn, Jiyeon

    2016-04-01

    To identify novel small molecules that induce selective cancer cell death, we screened a chemical library containing 1040 compounds in HT29 colon cancer and CCD18-Co normal colon cells, using a phenotypic cell-based viability assay system with the Cell Counting Kit-8 (CCK-8). We discovered a novel anthraquinone derivative, N-(4-[{(9,10-dioxo-9,10-dihydro-1-anthracenyl)sulfonyl}amino]phenyl)-N-methylacetamide (IMP1338), which was cytotoxic against the human colon cancer cells tested. The MTT cell viability assay showed that treatment with IMP1338 selectively inhibited HCT116, HCT116 p53(-/-), HT29, and A549 cancer cell proliferation compared to that of Beas2B normal epithelial cells. To elucidate the cellular mechanism underlying the cytotoxicity of IMP1338, we examined the effect of IMP1338 on the cell cycle distribution and death of cancer cells. IMP1338 treatment significantly arrested the cell cycle at S and G2/M phases by DNA damage and led to apoptotic cell death, which was determined using FACS analysis with Annexin V/PI double staining. Furthermore, IMP1338 increased caspase-3 cleavage in wild-type p53, p53 knockout HCT116, and HT29 cells as determined using immunoblotting. In addition, IMP1338 markedly induced the phosphorylation of histone H2AX and Chk1 in both cell lines while the combination of 5-fluorouracil (5-FU) and radiation inhibited the viability of HCT116, HCT116 p53(-/-), and HT29 cells compared to 5-FU or radiation alone. Our findings indicated that IMP1338 induced p53-independent cell death through S and G2/M phase arrest as well as DNA damage. These results provide a basis for future investigations assessing the promising anticancer properties of IMP1338.

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

    PubMed Central

    Klumpp, Dominik; Misovic, Milan; Szteyn, Kalina; Shumilina, Ekaterina; Rudner, Justine; Huber, Stephan M.

    2016-01-01

    Messenger RNA data of lymphohematopoietic cancer lines suggest a correlation between expression of the cation channel TRPM2 and the antiapoptotic protein Bcl-2. The latter is overexpressed in various tumor entities and mediates therapy resistance. Here, we analyzed the crosstalk between Bcl-2 and TRPM2 channels in T cell leukemia cells during oxidative stress as conferred by ionizing radiation (IR). To this end, the effects of TRPM2 inhibition or knock-down on plasma membrane currents, Ca2+ signaling, mitochondrial superoxide anion formation, and cell cycle progression were compared between irradiated (0–10 Gy) Bcl-2-overexpressing and empty vector-transfected Jurkat cells. As a result, IR stimulated a TRPM2-mediated Ca2+-entry, which was higher in Bcl-2-overexpressing than in control cells and which contributed to IR-induced G2/M cell cycle arrest. TRPM2 inhibition induced a release from G2/M arrest resulting in cell death. Collectively, this data suggests a pivotal function of TRPM2 in the DNA damage response of T cell leukemia cells. Apoptosis-resistant Bcl-2-overexpressing cells even can afford higher TRPM2 activity without risking a hazardous Ca2+-overload-induced mitochondrial superoxide anion formation. PMID:26839633

  11. Green tea polyphenols induce cell death in breast cancer MCF-7 cells through induction of cell cycle arrest and mitochondrial-mediated apoptosis*

    PubMed Central

    Liu, Shu-min; Ou, Shi-yi; Huang, Hui-hua

    2017-01-01

    In order to study the molecular mechanisms of green tea polyphenols (GTPs) in treatment or prevention of breast cancer, the cytotoxic effects of GTPs on five human cell lines (MCF-7, A549, Hela, PC3, and HepG2 cells) were determined and the antitumor mechanisms of GTPs in MCF-7 cells were analyzed. The results showed that GTPs exhibited a broad spectrum of inhibition against the detected cancer cell lines, particularly the MCF-7 cells. Studies on the mechanisms revealed that the main modes of cell death induced by GTPs were cell cycle arrest and mitochondrial-mediated apoptosis. Flow cytometric analysis showed that GTPs mediated cell cycle arrest at both G1/M and G2/M transitions. GTP dose dependently led to apoptosis of MCF-7 cells via the mitochondrial pathways, as evidenced by induction of chromatin condensation, reduction of mitochondrial membrane potential (ΔΨ m), improvement in the generation of reactive oxygen species (ROS), induction of DNA fragmentation, and activations of caspase-3 and caspase-9 in the present paper. PMID:28124838

  12. Induction of P3NS1 Myeloma Cell Death and Cell Cycle Arrest by Simvastatin and/or γ-Radiation.

    PubMed

    Abdelrahman, Ibrahim Y; Helwa, Reham; Elkashef, Hausein; Hassan, Nagwa H A

    2015-01-01

    The present study was conducted to investigate the effect of γ-radiation alone or combined with a cytotoxic drug, simvastatin, on viability and cell cycling of a myeloma cell line. P3NS1 myeloma cells were treated with the selected dose of simvastatin (0.1 μM/l) 24 hours prior to γ-irradiation (0.25, 0.5 and 1 Gy). The cell viability, induction of apoptosis, cell death, cell cycling, generation of ROS, and expression of P53, Bax, Bcl2, caspase3, PARP1 and Fas genes were estimated. The results indicated that simvastatin (0.1 μM/l) treatment for 24 hours prior to γ- irradiation increased cell death to 37.5% as compared to 4.81% by radiation (0.5 Gy) alone. It was found that simvastatin treatment before irradiation caused arrest of cells in G0/G1 and G2/M phases as assessed using flow cytometry. Interestingly, simvastatin treatment of P3NS1 cells increased the intracellular ROS production and decreased antioxidant enzyme activity with increased P53, Bax and Caspase3 gene expression while that of Bcl2 was decreased. Consequently, our results indicated that pre-treatment with simvastatin increased radio sensitivity of myeloma tumor cells in addition to apoptotic effects through an intrinsic mitochondrial pathway.

  13. 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

  14. Resveratrol mediates cell cycle arrest and cell death in human esophageal squamous cell carcinoma by directly targeting the EGFR signaling pathway

    PubMed Central

    Jin, Zixuan; Feng, Wei; Ji, Ying; Jin, Longyu

    2017-01-01

    Resveratrol is a small polyphenol that has been intensively studied in a wide spectrum of therapeutic fields. More recently, resveratrol has been demonstrated to exert its antitumor activity in numerous tumor models. The present study reported that resveratrol exhibited a marked anti-proliferative effect on human esophageal squamous cell carcinoma (ESCC) cells by inducing cell cycle G0/G1 phase arrest and cell death, which was associated with a decrease in the expression levels of cyclin D1 and an increase in cleaved PARP/cleaved caspase-3 expression levels. The mechanisms underlying the antitumor potency of resveratrol were principally attributed to the downregulation of epidermal growth factor receptor (EGFR) signaling. The western blotting results showed that exposure of ESCC cells to resveratrol inhibited EGF-induced EGFR activation in addition to decreasing the total protein levels of EGFR and membrane/nuclear localization. In summary, the results suggested that resveratrol, or an associated analog, may have a role in the management of human ESCC. PMID:28123566

  15. 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.

  16. 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

  17. Mechanisms of sulindac-induced apoptosis and cell cycle arrest.

    PubMed

    Jung, Barbara; Barbier, Valerie; Brickner, Howard; Welsh, John; Fotedar, Arun; McClelland, Michael

    2005-02-28

    The mechanism underlying the chemopreventive effects of the non-steroidal anti-inflammatory drug sulindac remains unclear. Its active metabolite, sulindac sulfide, induces cell cycle arrest as well as apoptosis in mammalian cell lines. We now show that in murine thymocytes, sulindac sulfide-induced cell death is p53, bax, Fas, and FasL independent. In contrast, bcl2 transgenic thymocytes are resistant to sulindac sulfide-induced apoptosis. In addition, we demonstrate that sulindac sulfide-induced cell cycle arrest in mouse embryonic fibroblasts (MEFs) is partly mediated by the retinoblastoma tumor suppressor protein (Rb) and the cyclin kinase inhibitor p21waf1/cip1. Furthermore, MEFs deficient in p21 or Rb are more susceptible to sulindac sulfide-induced cell death. These results suggest that sulindac may selectively target premalignant cells with cell cycle checkpoint deficits.

  18. Jellyfish extract induces apoptotic cell death through the p38 pathway and cell cycle arrest in chronic myelogenous leukemia K562 cells

    PubMed Central

    Kwak, Choong-Hwan; Abekura, Fukushi; Park, Jun-Young; Park, Nam Gyu; Chang, Young-Chae; Lee, Young-Choon; Chung, Tae-Wook; Ha, Ki-Tae; Son, Jong-Keun

    2017-01-01

    Jellyfish species are widely distributed in the world’s oceans, and their population is rapidly increasing. Jellyfish extracts have several biological functions, such as cytotoxic, anti-microbial, and antioxidant activities in cells and organisms. However, the anti-cancer effect of Jellyfish extract has not yet been examined. We used chronic myelogenous leukemia K562 cells to evaluate the mechanisms of anti-cancer activity of hexane extracts from Nomura’s jellyfish in vitro. In this study, jellyfish are subjected to hexane extraction, and the extract is shown to have an anticancer effect on chronic myelogenous leukemia K562 cells. Interestingly, the present results show that jellyfish hexane extract (Jellyfish-HE) induces apoptosis in a dose- and time-dependent manner. To identify the mechanism(s) underlying Jellyfish-HE-induced apoptosis in K562 cells, we examined the effects of Jellyfish-HE on activation of caspase and mitogen-activated protein kinases (MAPKs), which are responsible for cell cycle progression. Induction of apoptosis by Jellyfish-HE occurred through the activation of caspases-3,-8 and -9 and phosphorylation of p38. Jellyfish-HE-induced apoptosis was blocked by a caspase inhibitor, Z-VAD. Moreover, during apoptosis in K562 cells, p38 MAPK was inhibited by pretreatment with SB203580, an inhibitor of p38. SB203580 blocked jellyfish-HE-induced apoptosis. Additionally, Jellyfish-HE markedly arrests the cell cycle in the G0/G1 phase. Therefore, taken together, the results imply that the anti-cancer activity of Jellyfish-HE may be mediated apoptosis by induction of caspases and activation of MAPK, especially phosphorylation of p38, and cell cycle arrest at the Go/G1 phase in K562 cells. PMID:28133573

  19. Theracurmin® efficiently inhibits the growth of human prostate and bladder cancer cells via induction of apoptotic cell death and cell cycle arrest.

    PubMed

    Kang, Minyong; Ho, Jin-Nyoung; Kook, Ha Rim; Lee, Sangchul; Oh, Jong Jin; Hong, Sung Kyu; Lee, Sang Eun; Byun, Seok-Soo

    2016-03-01

    In the present study, we aimed to investigate the anticancer properties of Theracurmin®, a novel form of the yellow curry pigment curcumin, as well as explore the molecular mechanisms of the potential anticancer effects of Theracurmin® on human prostate cancer and bladder cancer cells in vitro. The proliferation of cancer cells was examined by using the Cell Counting Kit-8. The clonogenic growth potential was determined by clonogenic assay. Cell cycle distribution was evaluated by flow cytometry using propidium iodide staining. Western blot analysis was applied to explore the expression patterns of molecules associated with apoptotic cell death and cell cycle checkpoint. We noted that Theracurmin® and curcumin exhibited similar anticancer effects in both androgen-dependent and -independent human prostate cancer cells in a dose- and time-dependent manner. These agents reduced cell viability and clonogenic growth potential by inducing apoptosis and cell cycle disturbance in human prostate cancer cells. Theracurmin® and curcumin also exerted marked anticancer effects on human bladder cancer cells, even in cisplatin-resistant T24R2 cells, in a dose- and time-dependent manner. Moreover, Theracurmin® and curcumin treatment decreased cell viability and clonogenicity via induction of apoptotic cell death and cell cycle dysregulation in human bladder cancer cells. In conclusion, our study suggests that Theracurmin® has potential as an anticancer agent in complementary and alternative medicine for these urological cancers.

  20. Honokiol, a potential therapeutic agent, induces cell cycle arrest and program cell death in vitro and in vivo in human thyroid cancer cells.

    PubMed

    Lu, Chieh-Hsiang; Chen, Shu-Hsin; Chang, Yi-Sheng; Liu, Yi-Wen; Wu, Jin-Yi; Lim, Yun-Ping; Yu, Hui-I; Lee, Ying-Ray

    2017-01-01

    Thyroid cancer is the most common endocrine malignancy, the global incidence rate of which is rapidly rising. Surgery and radioiodine therapies are common and effective treatments only for nonmetastasized primary tumors. Therefore, effective treatment modalities are imperative for patients with radioiodine-resistant thyroid cancer. Honokiol, a biophenolic compound derived from Magnolia spp., has been shown have diverse biological and pharmacological activities, including anti-inflammatory, antioxidative, antiangiogenic, and anticancer properties. In the present study, three human thyroid cancer cell lines, namely anaplastic, follicular, and poorly differentiated thyroid cancer cells, were used to evaluate the chemotherapeutic activity of honokiol. Cell viability, cell cycle, apoptosis, and autophagy induction were determined through flow cytometry and western blot analysis. We found that honokiol treatment can suppress cell growth, induce cell cycle arrest, and enhance the induction of caspase-dependent apoptosis and autophagy in cancer cells. Moreover, honokiol treatment modulated signaling pathways including Akt/mTOR, ERK, JNK, and p38 in the studied cells. In addition, the antitumorigenic activity of honokiol was also confirmed in vitro and in vivo. Our data provide evidence that honokiol has a unique application in chemotherapy for human thyroid cancers.

  1. Sp1 acetylation is associated with loss of DNA binding at promoters associated with cell cycle arrest and cell death in a colon cell line.

    PubMed

    Waby, Jennifer S; Chirakkal, Haridasan; Yu, ChenWei; Griffiths, Gareth J; Benson, Roderick S P; Bingle, Colin D; Corfe, Bernard M

    2010-10-15

    Butyrate, a known histone deacetylase inhibitor (HDACi) and product of fibre fermentation, is postulated to mediate the protective effect of dietary fibre against colon cancer. The transcription factor Sp1 is a target of acetylation and is known to be associated with class I HDACs, including HDAC1. Sp1 is a ubiquitous transcription factor and Sp1-regulated genes include those involved in cell cycle regulation, apoptosis and lipogenesis: all major pathways in cancer development. The only known acetylated residue of Sp1 is lysine703 which resides in the DNA binding domain. Here we show that acetylated Sp1 loses p21- and bak-promoter -binding function in vitro. Furthermore treatment with a panel of HDAC inhibitors showed clustering of activities for a subset of inhibitors, causing G2 cell cycle arrest, Sp1 acetylation, p21 and Bak over-expression, all with very similar EC50 concentrations. These HDACi activities were not distributed according to the molecular class of compound. In order to mimic loss of binding, an siRNA strategy was used to reduce Sp1 expression. This resulted in altered expression of multiple elements of the p53/p21 pathway. Taken together our data suggest a mechanistic model for the chemopreventive actions of butyrate in colon epithelial cells, and provide new insight into the differential activities some classes of HDAC inhibitors.

  2. 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.

  3. The role of p21(waf1/cip1) and p27(Kip1) in HDACi-mediated tumor cell death and cell cycle arrest in the Eμ-myc model of B-cell lymphoma.

    PubMed

    Newbold, A; Salmon, J M; Martin, B P; Stanley, K; Johnstone, R W

    2014-11-20

    Following the establishment of histone deacetylases (HDACs) as promising therapeutic targets for the reversal of aberrant epigenetic states associated with cancer, the development of HDAC inhibitors (HDACi) and their underlying mechanisms of action has been a significant area of scientific interest. HDACi induce diverse biological responses including the inhibition of cell proliferation by blocking progression through the G1 or G2/M phases of the cell cycle. As a putative tumor-suppressor protein, p21(waf1/cip1) influences cell proliferation by inhibiting the activity of cyclin-cyclin-dependent kinase (CDK) complexes at the G1/S and G2/M cell cycle checkpoints. HDACi transcriptionally activate CDKN1A, and it has been proposed that induction of p21(waf1/cip1) can determine if a cell undergoes apoptosis or cell cycle arrest following HDACi treatment. In the Eμ-myc transgenic mouse model of B-cell lymphoma, knockout of cdkn1a had no effect on disease latency, indicating that p21(waf1/cip1) did not function as a tumor suppressor in this system. Although HDACi robustly induced expression of p21(waf1/cip1) in wild-type Eμ-myc lymphomas, deletion of cdkn1a did not sensitize the lymphoma cells to HDACi-induced apoptosis and HDACi-induced cell cycle arrest still occurred. However, knockdown of cdkn1b in cdkn1a knockout lymphomas resulted in defective vorinostat-mediated arrest at G1/S indicating an essential role of p27(Kip1) in mediating this biological response to vorinostat. These data demonstrate that induction of cdkn1a does not regulate HDACi-mediated tumor cell apoptosis and refute the notion that p21(waf1/cip1) is an obligate mediator of HDACi-induced cell cycle arrest.

  4. Death by Disimpaction: A Bradycardic Arrest Secondary to Rectal Manipulation

    PubMed Central

    Shea, Cory M.

    2016-01-01

    Rectal examination and fecal disimpaction are common procedures performed in the Emergency Department on a daily basis. Here, we report a rare case of a patient suffering a cardiac arrest and ultimately death likely due to rectal manipulation. A 66-year-old male presented to the Emergency Department (ED) with a complaint of abdominal distention and constipation. A rectal exam was performed. During the examination the patient became apneic. On the cardiac monitor the patient was found to be in pulseless electrical activity with a bradycardic rate. Our recommendation would be to provide adequate analgesia and close patient monitoring of those undergoing this procedure especially patients with significant stool burdens. PMID:28116179

  5. 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

  6. Acanthamoeba induces cell-cycle arrest in host cells.

    PubMed

    Sissons, James; Alsam, Selwa; Jayasekera, Samantha; Kim, Kwang Sik; Stins, Monique; Khan, Naveed Ahmed

    2004-08-01

    Acanthamoeba can cause fatal granulomatous amoebic encephalitis (GAE) and eye keratitis. However, the pathogenesis and pathophysiology of these emerging diseases remain unclear. In this study, the effects of Acanthamoeba on the host cell cycle using human brain microvascular endothelial cells (HBMEC) and human corneal epithelial cells (HCEC) were determined. Two isolates of Acanthamoeba belonging to the T1 genotype (GAE isolate) and T4 genotype (keratitis isolate) were used, which showed severe cytotoxicity on HBMEC and HCEC, respectively. No tissue specificity was observed in their ability to exhibit binding to the host cells. To determine the effects of Acanthamoeba on the host cell cycle, a cell-cycle-specific gene array was used. This screened for 96 genes specific for host cell-cycle regulation. It was observed that Acanthamoeba inhibited expression of genes encoding cyclins F and G1 and cyclin-dependent kinase 6, which are proteins important for cell-cycle progression. Moreover, upregulation was observed of the expression of genes such as GADD45A and p130 Rb, associated with cell-cycle arrest, indicating cell-cycle inhibition. Next, the effect of Acanthamoeba on retinoblastoma protein (pRb) phosphorylation was determined. pRb is a potent inhibitor of G1-to-S cell-cycle progression; however, its function is inhibited upon phosphorylation, allowing progression into S phase. Western blotting revealed that Acanthamoeba abolished pRb phosphorylation leading to cell-cycle arrest at the G1-to-S transition. Taken together, these studies demonstrated for the first time that Acanthamoeba inhibits the host cell cycle at the transcriptional level, as well as by modulating pRb phosphorylation using host cell-signalling mechanisms. A complete understanding of Acanthamoeba-host cell interactions may help in developing novel strategies to treat Acanthamoeba infections.

  7. Anticancer activity of taraxerol acetate in human glioblastoma cells and a mouse xenograft model via induction of autophagy and apoptotic cell death, cell cycle arrest and inhibition of cell migration.

    PubMed

    Hong, Jing-Fang; Song, Ying-Fang; Liu, Zheng; Zheng, Zhao-Cong; Chen, Hong-Jie; Wang, Shou-Sen

    2016-06-01

    The aim of the present study was to investigate the in vitro and in vivo anticancer and apoptotic effects of taraxerol acetate in U87 human glioblastoma cells. The effects on cell cycle phase distribution, cell cycle-associated proteins, autophagy, DNA fragmentation and cell migration were assessed. Cell viability was determined using the MTT assay, and phase contrast and fluorescence microscopy was utilized to determine the viability and apoptotic morphological features of the U87 cells. Flow cytometry using propidium iodide and Annexin V-fluorescein isothiocyanate demonstrated the effect of taraxerol acetate on the cell cycle phase distribution and apoptosis induction. Western blot analysis was performed to investigate the effect of the taraxerol acetate on cell cycle‑associated proteins and autophagy‑linked LC3B‑II proteins. The results demonstrated that taraxerol acetate induced dose‑ and time‑dependent cytotoxic effects in the U87 cells. Apoptotic induction following taraxerol acetate treatment was observed and the percentage of apoptotic cells increased from 7.3% in the control cells, to 16.1, 44.1 and 76.7% in the 10, 50 and 150 µM taraxerol acetate‑treated cells, respectively. Furthermore, taraxerol acetate treatment led to sub‑G1 cell cycle arrest with a corresponding decrease in the number of S‑phase cells. DNA fragments were observed as a result of the gel electrophoresis experiment following taraxerol acetate treatment. To investigate the inhibitory effects of taraxerol acetate on the migration of U87 cell, a wound healing assay was conducted. The number of cells that migrated to the scratched area decreased significantly following treatment with taraxerol acetate. In addition, taraxerol acetate inhibited tumor growth in a mouse xenograft model. Administration of 0.25 and 0.75 µg/g taraxerol acetate reduced the tumor weight from 1.2 g in the phosphate‑buffered saline (PBS)‑treated group (control) to 0.81 and 0.42

  8. Naphthazarin enhances ionizing radiation-induced cell cycle arrest and apoptosis in human breast cancer cells.

    PubMed

    Kim, Min Young; Park, Seong-Joon; Shim, Jae Woong; Yang, Kwangmo; Kang, Ho Sung; Heo, Kyu

    2015-04-01

    Naphthazarin (Naph, DHNQ, 5,8-dihydroxy-l,4-naphthoquinone) is one of the naturally available 1,4-naphthoquinone derivatives that are well-known for their anti-inflammatory, antioxidant, antibacterial and antitumor cytotoxic effects in cancer cells. Herein, we investigated whether Naph has effects on cell cycle arrest and apoptosis in MCF-7 human breast cancer cells exposed to ionizing radiation (IR). Naph reduced the MCF-7 cell viability in a dose-dependent manner. We also found that Naph and/or IR increased the p53-dependent p21 (CIP/WAF1) promoter activity. Noteworthy, our ChIP assay results showed that Naph and IR combined treatment activated the p21 promoter via inhibition of binding of multi-domain proteins, DNMT1, UHRF1 and HDAC1. Apoptosis and cell cycle analyses demonstrated that Naph and IR combined treatment induced cell cycle arrest and apoptosis in MCF-7 cells. Herein, we showed that Naph treatment enhances IR-induced cell cycle arrest and death in MCF-7 human breast cancer cells through the p53-dependent p21 activation mechanism. These results suggest that Naph might sensitize breast cancer cells to radiotherapy by enhancing the p53-p21 mechanism activity.

  9. How Can Death Due to Sudden Cardiac Arrest Be Prevented?

    MedlinePlus

    ... Trials Links Related Topics Arrhythmia Automated External Defibrillator Coronary Heart Disease Heart Failure Long QT Syndrome Send a link ... First Sudden Cardiac Arrest If you have severe coronary heart disease (CHD), you're at increased risk for SCA. ...

  10. 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.

  11. Purified Lesser weever fish venom (Trachinus vipera) induces eryptosis, apoptosis and cell cycle arrest

    PubMed Central

    Fezai, Myriam; Slaymi, Chaker; Ben-Attia, Mossadok; Lang, Florian; Jemaà, Mohamed

    2016-01-01

    Accidents caused by the sting of Trachinus vipera (known as Lesser weever fish) are relatively common in shallow waters of the Mediterranean. Symptoms after the sting vary from severe pain to edema or even tissue necrosis in some cases. Here we show that purified Lesser weever fish venom induces eryptosis, the suicidal erythrocyte death, and apoptosis of human colon carcinoma cells. The venom leads to erythrocyte shrinkage, phosphatidylserine translocation and increased intracellular Ca2+, events typical for eryptosis. According to mitochondrial staining cancer cells dyed after the activation of the intrinsic apoptotic pathway. Trachinus vipera venom further causes cell cycle arrest. PMID:27995979

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

    PubMed

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

    2016-04-23

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

  13. [Cell cycle arrest at M phase induced by vinblastine in MOLT-4 cells].

    PubMed

    Zhong, Yi-Sheng; Pan, Chang-Chuan; Jin, Chang-Nan; Li, Jian-Jun; Xiong, Gong-Peng; Zhang, Jian-Xi; Gong, Jian-Ping

    2009-04-01

    This study was purposed to investigate the biological effect of vinblastine (VLS), usually known as inductor of mitotic arrest, on MOLT-4 of ALL cells and to evaluate its significance. The cell arrest in M phase and/or cell apoptosis were induced by treatment of MOLT-4 cells with 0.05 microg/ml VLS for 0 - 12 hours; the DNA histogram was detected by flow cytometry; the morphological changes of cells were observed by confocal microscopy; the cell cycle distribution, cell apoptosis and morphological changes of cells before and after arrest were analyzed by using arrest increasing rate (AIR), arrest efficiency (AE), apoptosis rate (AR) and morphologic parameters respectively. The results indicated that the cell arrest did not accompanied by significant increase of apoptosis rate; the DNA histogram of cell arrest showed dynamic change of cell cycle in time-dependent manner; the arrest efficiency could be quantified. The cell arrest at M phase was accompanied by cell stack in S phase, the cell proliferation rate dropped after cell arrest occurred. The cells arrested at M phase possessed of characteristic morphologic features in cell mitosis. It is concluded that the vinblastine can solely induce arrest of MOLT-4 cells at M phase. This study provides experimental basis for further investigating the relation of cell cycle arrest to apoptosis, mechanism of checkpoint and development of new anticancer drugs.

  14. 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.

  15. Tangeretin induces cell cycle arrest and apoptosis through upregulation of PTEN expression in glioma cells.

    PubMed

    Ma, Li-Li; Wang, Da-Wei; Yu, Xu-Dong; Zhou, Yan-Ling

    2016-07-01

    Tangeretin (TANG), present in peel of citrus fruits, has been shown to various medicinal properties such as chemopreventive and neuroprotective. However, the chemopreventive effect of TANG on glioblastoma cells has not been examined. The present study was designed to explore the anticancer potential of TANG in glioblastoma cells and to investigate the related mechanism. Human glioblastoma U-87MG and LN-18 cells were treated with 45μM concentration of TANG and cell growth was measured by MTT assay. The cell cycle distribution and cell death were measured by flow cytometry. The expression of cell cycle and apoptosis related genes were analyzed by quantitative RT-PCR and western blot. The cells treated with TANG were significantly increased cell growth suppression and cell death effects than vehicle treated cells. Further, TANG treatment increases G2/M arrest and apoptosis by modulating PTEN and cell-cycle regulated genes such as cyclin-D and cdc-2 mRNA and protein expressions. Moreover, the ability of TANG to decrease cell growth and to induce cell death was compromised when PTEN was knockdown by siRNA. Taken together, the chemopreventive effect of TANG is associated with regulation of cell-cycle and apoptosis in glioblastoma, thereby attenuating glioblastoma cell growth. Hence, the present findings suggest that TANG may be a therapeutic agent for glioblastoma treatment.

  16. 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

  17. High-dose irradiation induces cell cycle arrest, apoptosis, and developmental defects during Drosophila oogenesis.

    PubMed

    Shim, Hee Jin; Lee, Eun-Mi; Nguyen, Long Duy; Shim, Jaekyung; Song, Young-Han

    2014-01-01

    Ionizing radiation (IR) treatment induces a DNA damage response, including cell cycle arrest, DNA repair, and apoptosis in metazoan somatic cells. Because little has been reported in germline cells, we performed a temporal analysis of the DNA damage response utilizing Drosophila oogenesis as a model system. Oogenesis in the adult Drosophila female begins with the generation of 16-cell cyst by four mitotic divisions of a cystoblast derived from the germline stem cells. We found that high-dose irradiation induced S and G2 arrests in these mitotically dividing germline cells in a grp/Chk1- and mnk/Chk2-dependent manner. However, the upstream kinase mei-41, Drosophila ATR ortholog, was required for the S-phase checkpoint but not for the G2 arrest. As in somatic cells, mnk/Chk2 and dp53 were required for the major cell death observed in early oogenesis when oocyte selection and meiotic recombination occurs. Similar to the unscheduled DNA double-strand breaks (DSBs) generated from defective repair during meiotic recombination, IR-induced DSBs produced developmental defects affecting the spherical morphology of meiotic chromosomes and dorsal-ventral patterning. Moreover, various morphological abnormalities in the ovary were detected after irradiation. Most of the IR-induced defects observed in oogenesis were reversible and were restored between 24 and 96 h after irradiation. These defects in oogenesis severely reduced daily egg production and the hatch rate of the embryos of irradiated female. In summary, irradiated germline cells induced DSBs, cell cycle arrest, apoptosis, and developmental defects resulting in reduction of egg production and defective embryogenesis.

  18. Parkin induces G2/M cell cycle arrest in TNF-α-treated HeLa cells.

    PubMed

    Lee, Min Ho; Cho, Yoonjung; Jung, Byung Chul; Kim, Sung Hoon; Kang, Yeo Wool; Pan, Cheol-Ho; Rhee, Ki-Jong; Kim, Yoon Suk

    2015-08-14

    Parkin is a known tumor suppressor. However, the mechanism by which parkin acts as a tumor suppressor remains to be fully elucidated. Previously, we reported that parkin expression induces caspase-dependent apoptotic cell death in TNF-α-treated HeLa cells. However, at that time, we did not consider the involvement of parkin in cell cycle control. In the current study, we investigated whether parkin is involved in cell cycle regulation and suppression of cancer cell growth. In our cell cycle analyses, parkin expression induced G2/M cell cycle arrest in TNF-α-treated HeLa cells. To elucidate the mechanism(s) by which parkin induces this G2/M arrest, we analyzed cell cycle regulatory molecules involved in the G2/M transition. Parkin expression induced CDC2 phosphorylation which is known to inhibit CDC2 activity and cause G2/M arrest. Cyclin B1, which is degraded during the mitotic transition, accumulated in response to parkin expression, thereby indicating parkin-induced G2/M arrest. Next, we established that Myt1, which is known to phosphorylate and inhibit CDC2, increased following parkin expression. In addition, we found that parkin also induces increased Myt1 expression, G2/M arrest, and reduced cell viability in TNF-α-treated HCT15 cells. Furthermore, knockdown of parkin expression by parkin-specific siRNA decreased Myt1 expression and phosphorylation of CDC2 and resulted in recovered cell viability. These results suggest that parkin acts as a crucial molecule causing cell cycle arrest in G2/M, thereby suppressing tumor cell growth.

  19. 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.

  20. 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

  1. 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

  2. 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

  3. 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

  4. Specific loss of apoptotic but not cell-cycle arrest function in a human tumor derived p53 mutant.

    PubMed Central

    Rowan, S; Ludwig, R L; Haupt, Y; Bates, S; Lu, X; Oren, M; Vousden, K H

    1996-01-01

    The p53 tumor-suppressor gene product is frequently inactivated in malignancies by point mutation. Although most tumor-derived p53 mutants show loss of sequence specific transcriptional activation, some mutants have been identified which retain this activity. One such mutant, p53175P, is defective for the suppression of transformation in rodent cells, despite retaining the ability to suppress the growth of p53-null human cells. We now demonstrate that p53175P can induce a cell-cycle arrest in appropriate cell types but shows loss of apoptotic function. Our results therefore support a direct role of p53 transcriptional activation in mediating a cell-cycle arrest and demonstrate that such activity is not sufficient for the full apoptotic response. These data suggest that either p53 can induce apoptosis through a transcriptionally independent mechanism, a function lost by p53175P, or that this mutant has specifically lost the ability to activate genes which contribute to cell death, despite activation of genes responsible for the G1 arrest. This dissociation of the cell-cycle arrest and apoptotic activities of p53 indicates that inactivation of p53 apoptotic function without concomitant loss of growth inhibition can suffice to relieve p53-dependent tumor-suppression in vivo and thereby contribute to tumor development. Images PMID:8631304

  5. 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.

  6. 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.

  7. 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

  8. 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.

  9. CIL-102-Induced Cell Cycle Arrest and Apoptosis in Colorectal Cancer Cells via Upregulation of p21 and GADD45

    PubMed Central

    Huang, Wen-Shih; Kuo, Yi-Hung; Kuo, Hsing-Chun; Hsieh, Meng-Chiao; Huang, Cheng-Yi; Lee, Ko-Chao; Lee, Kam-Fai; Shen, Chien-Heng; Tung, Shui-Yi; Teng, Chih-Chuan

    2017-01-01

    CIL-102 (1-[4-(furo[2,3-b]quinolin-4-ylamino)phenyl]ethanone) is a well-known, major active agent of the alkaloid derivative of Camptotheca acuminata with valuable biological properties, including anti-tumorigenic activity. In this study, we investigated the molecular mechanisms by which CIL-102 mediated the induction of cell death, and we performed cell cycle G2/M arrest to clarify molecular changes in colorectal cancer cells (CRC). Treatment of DLD-1 cells with CIL-102 resulted in triggering the extrinsic apoptosis pathway through the activation of Fas-L, caspase-8 and the induction of Bid cleavage and cytochrome c release in a time-dependent manner. In addition, CIL-102 mediated apoptosis and G2/M arrest by phosphorylation of the Jun N-terminus kinase (JNK1/2) signaling pathway. This resulted in the expression of NFκB p50, p300 and CREB-binding protein (CBP) levels, and in the induction of p21 and GADD45 as well as the decreased association of cdc2/cyclin B. Furthermore, treatment with the JNK1/2 (SP600125), NFκB (PDTI) or the p300/CBP (C646) inhibitors abolished CIL-102-induced cell cycle G2/M arrest and reversed the association of cdc2 with cyclin B. Therefore, we demonstrated that there was an increase in the cellular levels of p21 and GADD45 by CIL-102 reduction in cell viability and cell cycle arrest via the activation of the JNK1/2, NFκB p50, p300 and CBP signaling modules. Collectively, our results demonstrated that CIL-102 induced cell cycle arrest and apoptosis of colon cancer cells by upregulating p21 and GADD45 expression and by activating JNK1/2, NFκB p50 and p300 to provide a new mechanism for CIL-102 treatment. PMID:28068431

  10. Cell death and growth arrest in response to photodynamic therapy with membrane-bound photosensitizers.

    PubMed

    Piette, Jacques; Volanti, Cédric; Vantieghem, Annelies; Matroule, Jean-Yves; Habraken, Yvette; Agostinis, Patrizia

    2003-10-15

    Photodynamic therapy (PDT) is a treatment for cancer and for certain benign conditions that is based on the use of a photosensitizer and light to produce reactive oxygen species in cells. Many of the photosensitizers currently used in PDT localize in different cell compartments such as mitochondria, lysosomes, endoplasmic reticulum and generate cell death by triggering necrosis and/or apoptosis. Efficient cell death is observed when light, oxygen and the photosensitizer are not limiting ("high dose PDT"). When one of these components is limiting ("low dose PDT"), most of the cells do not immediately undergo apoptosis or necrosis but are growth arrested with several transduction pathways activated. This commentary will review the mechanism of apoptosis and growth arrest mediated by two important PDT agents, i.e. pyropheophorbide and hypericin.

  11. 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).

  12. Danusertib, a potent pan-Aurora kinase and ABL kinase inhibitor, induces cell cycle arrest and programmed cell death and inhibits epithelial to mesenchymal transition involving the PI3K/Akt/mTOR-mediated signaling pathway in human gastric cancer AGS and NCI-N78 cells.

    PubMed

    Yuan, Chun-Xiu; Zhou, Zhi-Wei; Yang, Yin-Xue; He, Zhi-Xu; Zhang, Xueji; Wang, Dong; Yang, Tianxing; Pan, Si-Yuan; Chen, Xiao-Wu; Zhou, Shu-Feng

    2015-01-01

    Gastric cancer is the second leading cause of cancer-related death worldwide, with a poor response to current chemotherapy. Danusertib is a pan-inhibitor of the Aurora kinases and a third-generation Bcr-Abl tyrosine kinase inhibitor with potent anticancer effects, but its antitumor effect and underlying mechanisms in the treatment of human gastric cancer are unknown. This study aimed to investigate the effects of danusertib on cell growth, apoptosis, autophagy, and epithelial to mesenchymal transition and the molecular mechanisms involved in human gastric cancer AGS and NCI-N78 cells. The results showed that danusertib had potent growth-inhibitory, apoptosis-inducing, and autophagy-inducing effects on AGS and NCI-N78 cells. Danusertib arrested AGS and NCI-N78 cells in G2/M phase, with downregulation of expression of cyclin B1 and cyclin-dependent kinase 1 and upregulation of expression of p21 Waf1/Cip1, p27 Kip1, and p53. Danusertib induced mitochondria-mediated apoptosis, with an increase in expression of proapoptotic protein and a decrease in antiapoptotic proteins in both cell lines. Danusertib induced release of cytochrome c from the mitochondria to the cytosol and triggered activation of caspase 9 and caspase 3 in AGS and NCI-N78 cells. Further, danusertib induced autophagy, with an increase in expression of beclin 1 and conversion of microtubule-associated protein 1A/1B-light chain 3 (LC3-I) to LC3-II in both cell lines. Inhibition of phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) and p38 mitogen-activated protein kinase pathways as well as activation of 5' AMP-activated protein kinase contributed to the proautophagic effect of danusertib in AGS and NCI-N78 cells. SB202191 and wortmannin enhanced the autophagy-inducing effect of danusertib in AGS and NCI-N78 cells. In addition, danusertib inhibited epithelial to mesenchymal transition with an increase in expression of E-cadherin and a decrease in expression of

  13. Danusertib, a potent pan-Aurora kinase and ABL kinase inhibitor, induces cell cycle arrest and programmed cell death and inhibits epithelial to mesenchymal transition involving the PI3K/Akt/mTOR-mediated signaling pathway in human gastric cancer AGS and NCI-N78 cells

    PubMed Central

    Yuan, Chun-Xiu; Zhou, Zhi-Wei; Yang, Yin-Xue; He, Zhi-Xu; Zhang, Xueji; Wang, Dong; Yang, Tianxing; Pan, Si-Yuan; Chen, Xiao-Wu; Zhou, Shu-Feng

    2015-01-01

    Gastric cancer is the second leading cause of cancer-related death worldwide, with a poor response to current chemotherapy. Danusertib is a pan-inhibitor of the Aurora kinases and a third-generation Bcr-Abl tyrosine kinase inhibitor with potent anticancer effects, but its antitumor effect and underlying mechanisms in the treatment of human gastric cancer are unknown. This study aimed to investigate the effects of danusertib on cell growth, apoptosis, autophagy, and epithelial to mesenchymal transition and the molecular mechanisms involved in human gastric cancer AGS and NCI-N78 cells. The results showed that danusertib had potent growth-inhibitory, apoptosis-inducing, and autophagy-inducing effects on AGS and NCI-N78 cells. Danusertib arrested AGS and NCI-N78 cells in G2/M phase, with downregulation of expression of cyclin B1 and cyclin-dependent kinase 1 and upregulation of expression of p21 Waf1/Cip1, p27 Kip1, and p53. Danusertib induced mitochondria-mediated apoptosis, with an increase in expression of proapoptotic protein and a decrease in antiapoptotic proteins in both cell lines. Danusertib induced release of cytochrome c from the mitochondria to the cytosol and triggered activation of caspase 9 and caspase 3 in AGS and NCI-N78 cells. Further, danusertib induced autophagy, with an increase in expression of beclin 1 and conversion of microtubule-associated protein 1A/1B-light chain 3 (LC3-I) to LC3-II in both cell lines. Inhibition of phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) and p38 mitogen-activated protein kinase pathways as well as activation of 5′ AMP-activated protein kinase contributed to the proautophagic effect of danusertib in AGS and NCI-N78 cells. SB202191 and wortmannin enhanced the autophagy-inducing effect of danusertib in AGS and NCI-N78 cells. In addition, danusertib inhibited epithelial to mesenchymal transition with an increase in expression of E-cadherin and a decrease in expression

  14. Cell cycle-arrested tumor cells exhibit increased sensitivity towards TRAIL-induced apoptosis

    PubMed Central

    Ehrhardt, H; Wachter, F; Grunert, M; Jeremias, I

    2013-01-01

    Resting tumor cells represent a huge challenge during anticancer therapy due to their increased treatment resistance. TNF-related apoptosis-inducing ligand (TRAIL) is a putative future anticancer drug, currently in phases I and II clinical studies. We recently showed that TRAIL is able to target leukemia stem cell surrogates. Here, we tested the ability of TRAIL to target cell cycle-arrested tumor cells. Cell cycle arrest was induced in tumor cell lines and xenografted tumor cells in G0, G1 or G2 using cytotoxic drugs, phase-specific inhibitors or RNA interference against cyclinB and E. Biochemical or molecular arrest at any point of the cell cycle increased TRAIL-induced apoptosis. Accordingly, when cell cycle arrest was disabled by addition of caffeine, the antitumor activity of TRAIL was reduced. Most important for clinical translation, tumor cells from three children with B precursor or T cell acute lymphoblastic leukemia showed increased TRAIL-induced apoptosis upon knockdown of either cyclinB or cyclinE, arresting the cell cycle in G2 or G1, respectively. Taken together and in contrast to most conventional cytotoxic drugs, TRAIL exerts enhanced antitumor activity against cell cycle-arrested tumor cells. Therefore, TRAIL might represent an interesting drug to treat static-tumor disease, for example, during minimal residual disease. PMID:23744361

  15. The p75{sup NTR} tumor suppressor induces cell cycle arrest facilitating caspase mediated apoptosis in prostate tumor cells

    SciTech Connect

    Khwaja, Fatima; Tabassum, Arshia; Allen, Jeff; Djakiew, Daniel . E-mail: djakiewd@georgetown.edu

    2006-03-24

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

  16. Normoxic resuscitation after cardiac arrest protects against hippocampal oxidative stress, metabolic dysfunction, and neuronal death

    PubMed Central

    Vereczki, Viktoria; Martin, Erica; Rosenthal, Robert E; Hof, Patrick R; Hoffman, Gloria E; Fiskum, Gary

    2008-01-01

    Resuscitation and prolonged ventilation using 100% oxygen after cardiac arrest is standard clinical practice despite evidence from animal models indicating that neurologic outcome is improved using normoxic compared with hyperoxic resuscitation. This study tested the hypothesis that normoxic ventilation during the first hour after cardiac arrest in dogs protects against prelethal oxidative stress to proteins, loss of the critical metabolic enzyme pyruvate dehydrogenase complex (PDHC), and minimizes subsequent neuronal death in the hippocampus. Anesthetized beagles underwent 10 mins ventricular fibrillation cardiac arrest, followed by defibrillation and ventilation with either 21% or 100% O2. At 1 h after resuscitation, the ventilator was adjusted to maintain normal blood gas levels in both groups. Brains were perfusion-fixed at 2 h reperfusion and used for immunohistochemical measurements of hippocampal nitrotyrosine, a product of protein oxidation, and the E1α subunit of PDHC. In hyperoxic dogs, PDHC immunostaining diminished by approximately 90% compared with sham-operated dogs, while staining in normoxic animals was not significantly different from nonischemic dogs. Protein nitration in the hippocampal neurons of hyperoxic animals was 2–3 times greater than either sham-operated or normoxic resuscitated animals at 2 h reperfusion. Stereologic quantification of neuronal death at 24 h reperfusion showed a 40% reduction using normoxic compared with hyperoxic resuscitation. These results indicate that postischemic hyperoxic ventilation promotes oxidative stress that exacerbates prelethal loss of pyruvate dehydrogenase and delayed hippocampal neuronal cell death. Moreover, these findings indicate the need for clinical trials comparing the effects of different ventilatory oxygen levels on neurologic outcome after cardiac arrest. PMID:16251887

  17. Centchroman induces redox-dependent apoptosis and cell-cycle arrest in human endometrial cancer cells.

    PubMed

    Shyam, Hari; Singh, Neetu; Kaushik, Shweta; Sharma, Ramesh; Balapure, Anil K

    2017-04-01

    Centchroman (CC) or Ormeloxifene has been shown to induce apoptosis and cell cycle arrest in various types of cancer cells. This has, however, not been addressed for endometrial cancer cells where its (CC) mechanism of action remains unclear. This study focuses on the basis of antineoplasticity of CC by blocking the targets involved in the cell cycle, survival and apoptosis in endometrial cancer cells. Ishikawa Human Endometrial Cancer Cells were cultured under estrogen deprived medium, exposed to CC and analyzed for proliferation and apoptosis. Additionally, we also analyzed oxidative stress induced by CC. Cell viability studies confirmed the IC50 of CC in Ishikawa cells to be 20 µM after 48 h treatment. CC arrests the cells in G0/G1 phase through cyclin D1 and cyclin E mediated pathways. Phosphatidylserine externalization, nuclear morphology changes, DNA fragmentation, PARP cleavage, and alteration of Bcl-2 family protein expression clearly suggest ongoing apoptosis in the CC treated cells. Activation of caspase 3 & 9, up-regulation of AIF and inhibition of apoptosis by z-VAD-fmk clearly explains the participation of the intrinsic pathway of programmed cell death. Further, the increase of ROS, loss of MMP, inhibition of antioxidant (MnSOD, Cu/Zn-SOD and GST) and inhibition of apoptosis with L-NAC suggests CC induced oxidative stress leading to apoptosis via mitochondria mediated pathway. Therefore, CC could be a potential therapeutic agent for the treatment of Endometrial Cancer adjunct to its utility as a contraceptive and an anti-breast cancer agent.

  18. 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.

  19. Loss of p53-mediated cell-cycle arrest, senescence and apoptosis promotes genomic instability and premature aging.

    PubMed

    Li, Tongyuan; Liu, Xiangyu; Jiang, Le; Manfredi, James; Zha, Shan; Gu, Wei

    2016-03-15

    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.

  20. The oxygen-rich postnatal environment induces cardiomyocyte cell-cycle arrest through DNA damage response.

    PubMed

    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

    2014-04-24

    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 postnatal 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, whereas hyperoxemia and ROS generators shorten it. These findings uncover a 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 an important component of cardiomyocyte proliferation-based therapeutic approaches.

  1. Induction of Apoptosis and Antiproliferative Activity of Naringenin in Human Epidermoid Carcinoma Cell through ROS Generation and Cell Cycle Arrest

    PubMed Central

    Jafri, Asif; Ahmad, Sheeba; Afzal, Mohammad; Arshad, Md

    2014-01-01

    A natural predominant flavanone naringenin, especially abundant in citrus fruits, has a wide range of pharmacological activities. The search for antiproliferative agents that reduce skin carcinoma is a task of great importance. The objective of this study was to analyze the anti-proliferative and apoptotic mechanism of naringenin using MTT assay, DNA fragmentation, nuclear condensation, change in mitochondrial membrane potential, cell cycle kinetics and caspase-3 as biomarkers and to investigate the ability to induce reactive oxygen species (ROS) initiating apoptotic cascade in human epidermoid carcinoma A431 cells. Results showed that naringenin exposure significantly reduced the cell viability of A431 cells (p<0.01) with a concomitant increase in nuclear condensation and DNA fragmentation in a dose dependent manner. The intracellular ROS generation assay showed statistically significant (p<0.001) dose-related increment in ROS production for naringenin. It also caused naringenin-mediated epidermoid carcinoma apoptosis by inducing mitochondrial depolarization. Cell cycle study showed that naringenin induced cell cycle arrest in G0/G1 phase of cell cycle and caspase-3 analysis revealed a dose dependent increment in caspase-3 activity which led to cell apoptosis. This study confirms the efficacy of naringenin that lead to cell death in epidermoid carcinoma cells via inducing ROS generation, mitochondrial depolarization, nuclear condensation, DNA fragmentation, cell cycle arrest in G0/G1 phase and caspase-3 activation. PMID:25330158

  2. 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

  3. 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.

  4. Capillarisin Exhibits Anticancer Effects by Inducing Apoptosis, Cell Cycle Arrest and Mitochondrial Membrane Potential Loss in Osteosarcoma Cancer Cells (HOS).

    PubMed

    Chen, N-J; Hao, F-Y; Liu, H; Zhao, H; Li, J-M

    2015-08-01

    The aim of the present study was to assess the anticancer activity of capillarisin against human osteosarcoma (HOS) cancer cells in vitro. Cell viability after capillarisin drug treatment and evaluated by MTT assay. The extent of cell death induced by capillarisin was estimated by using lactate dehydrogenase (LDH) assay. The effect of capillarisin on cell cycle phase distribution and mitochondrial membrane potential (ΛΨm) was demonstrated via flow cytometry using propidium iodide (PI) and rhodamine-123 (Rh-123) DNA-binding fluorescent dyes respectively. Fluorescence microscopy was employed to examine the morphological changes in osteosarcoma cancer cells and presence of apoptotic bodies following capillarisin treatment. The results of this study revealed that capillarisin induced dose-dependent growth inhibition of these cancer cells after 12-h of incubation. Further, capillarisin induced significant release of LDH from these cell cultures and this LDH release was much more noticeable at higher concentrations of capillarisin. Hoechst 33258 staining revealed characteristic morphological features of apoptosis triggered by capillarisin treatment. Cell cycle analysis revealed that capillarisin induced dose-dependent G0/G1-phase cell cycle arrest. Capillarisin also trigerred a progressive and dose-dependent reduction in the mitochondrial membrane potential. In conclusion, capillarisin inhibits cancer cell growth of osteosarcoma cells by inducing apoptosis accompanied with G0/G1-phase cell cycle arrest and loss in mitochondrial membrane potential.

  5. 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.

  6. 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

  7. 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.

  8. Proteomic analysis of the response to cell cycle arrests in human myeloid leukemia cells

    PubMed Central

    Ly, Tony; Endo, Aki; Lamond, Angus I

    2015-01-01

    Abstract Previously, we analyzed protein abundance changes across a ‘minimally perturbed’ cell cycle by using centrifugal elutriation to differentially enrich distinct cell cycle phases in human NB4 cells (Ly et al., 2014). In this study, we compare data from elutriated cells with NB4 cells arrested at comparable phases using serum starvation, hydroxyurea, or RO-3306. While elutriated and arrested cells have similar patterns of DNA content and cyclin expression, a large fraction of the proteome changes detected in arrested cells are found to reflect arrest-specific responses (i.e., starvation, DNA damage, CDK1 inhibition), rather than physiological cell cycle regulation. For example, we show most cells arrested in G2 by CDK1 inhibition express abnormally high levels of replication and origin licensing factors and are likely poised for genome re-replication. The protein data are available in the Encyclopedia of Proteome Dynamics (http://www.peptracker.com/epd/), an online, searchable resource. DOI: http://dx.doi.org/10.7554/eLife.04534.001 PMID:25555159

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

    PubMed Central

    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

  10. 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

  11. Adenovirus-mediated p53 gene transduction inhibits telomerase activity independent of its effects on cell cycle arrest and apoptosis in human pancreatic cancer cells.

    PubMed

    Kusumoto, M; Ogawa, T; Mizumoto, K; Ueno, H; Niiyama, H; Sato, N; Nakamura, M; Tanaka, M

    1999-08-01

    Evidence for a relationship between overexpression of wild-type p53 and telomerase activity remains controversial. We investigated whether p53 gene transduction could cause telomerase inhibition in pancreatic cancer cell lines, focusing on the relation of transduction to growth arrest, cell cycle arrest, and apoptotic cell death. The cells were infected with recombinant adenovirus expressing wild-type p53 or p21WAF1 at a multiplicity of infection of 100 or were continuously exposed to 10 microM VP-16, which is well known to induce apoptosis. Adenovirus-mediated p53 gene transduction caused G1 cell cycle arrest, apoptosis, and resultant growth inhibition in MIA PaCa-2 cells; the cell number 2 days after infection was 50% of preinfection value, and 13% of the cells were dead. Moreover, the transduction resulted in complete depression of telomerase activity through down-regulation of hTERT mRNA expression. In contrast, p21WAF1 gene transduction only arrested cell growth and cell cycle at G1 phase, and VP-16 treatment inhibited cell growth with G2-M arrest and apoptosis; after treatment, the cell number was 73% of pretreatment, and 12% of the cells were dead. Neither p21WAF1 gene transduction nor VP-16 treatment caused telomerase inhibition. Similar results were obtained in two other pancreatic cancer cell lines, SUIT-2 and AsPC-1. Thus, our results demonstrate that the p53 gene transduction directly inhibits telomerase activity, independent of its effects on cell growth arrest, cell cycle arrest, and apoptosis.

  12. 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.

  13. Kaempferol induces cell cycle arrest and apoptosis in renal cell carcinoma through EGFR/p38 signaling.

    PubMed

    Song, Wenbin; Dang, Qiang; Xu, Defeng; Chen, Yule; Zhu, Guodong; Wu, Kaijie; Zeng, Jin; Long, Qingzhi; Wang, Xinyang; He, Dalin; Li, Lei

    2014-03-01

    Kaempferol has been shown to inhibit cell growth, induce apoptosis and cell cycle arrest in several tumors, but not in renal cell carcinoma (RCC). In the present study, we investigated the effects of kaempferol and the underlying mechanism(s) on the cell growth of RCC cells. MTT assay and colony formation assay were used to study cell growth, and flow cytometry was used to study apoptosis and cell cycles in different RCC cells treated with various doses of kaempferol. A significant inhibition on cell growth, induction of apoptosis and cell cycle arrest were observed in 786-O and 769-P cells after kaempferol treatment compared with the control group. Moreover, the results clearly showed that kaempferol causes a strong inhibition of the activation of the EGFR/p38 signaling pathways, upregulation of p21 expression and downregulation of cyclin B1 expression in human RCC cells, together with activation of PARP cleavages, induction of apoptotic death and inhibition of cell growth. Collectively, our results suggest that kaempferol may serve as a candidate for chemo-preventive or chemotherapeutic agents for RCC.

  14. Valproic acid induces apoptosis and cell cycle arrest in poorly differentiated thyroid cancer cells.

    PubMed

    Catalano, Maria G; Fortunati, Nicoletta; Pugliese, Mariateresa; Costantino, Lucia; Poli, Roberta; Bosco, Ornella; Boccuzzi, Giuseppe

    2005-03-01

    Poorly differentiated thyroid carcinoma is an aggressive human cancer that is resistant to conventional therapy. Histone deacetylase inhibitors are a promising class of drugs, acting as antiproliferative agents by promoting differentiation, as well as inducing apoptosis and cell cycle arrest. Valproic acid (VPA), a class I selective histone deacetylase inhibitor widely used as an anticonvulsant, promotes differentiation in poorly differentiated thyroid cancer cells by inducing Na(+)/I(-) symporter and increasing iodine uptake. Here, we show that it is also highly effective at suppressing growth in poorly differentiated thyroid cancer cell lines (N-PA and BHT-101). Apoptosis induction and cell cycle arrest are the underlying mechanisms of VPA's effect on cell growth. It induces apoptosis by activating the intrinsic pathway; caspases 3 and 9 are activated but not caspase 8. Cell cycle is selectively arrested in G(1) and is associated with the increased expression of p21 and the reduced expression of cyclin A. Both apoptosis and cell cycle arrest are induced by treatment with 1 mm VPA, a dose that promotes cell redifferentiation and that is slightly above the serum concentration reached in patients treated for epilepsy. These multifaceted properties make VPA of clinical interest as a new approach to treating poorly differentiated thyroid cancer.

  15. 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

  16. Effects of curine in HL-60 leukemic cells: cell cycle arrest and apoptosis induction.

    PubMed

    Dantas, Bruna Braga; Faheina-Martins, Gláucia Veríssimo; Coulidiati, Tangbadioa Hervé; Bomfim, Caio César Barbosa; da Silva Dias, Celidarque; Barbosa-Filho, José Maria; Araújo, Demetrius Antônio Machado

    2015-04-01

    Curine is a natural alkaloid isolated from Chondrodendron platyphyllum and it has been reported that this alkaloid has vasodilatory and anti-inflammatory effects. The aim of this study is to analyze the cytotoxic effects of curine in cancer cell lines HL-60, K562, and HT-29, and in primary cultures of peripheral blood mononuclear cells (PBMC). Cells were treated with curine (from 3 to 15 µM) for 24 and 48 h. Cell viability was analyzed by the 3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium bromide (MTT) test and flow cytometry with propidium iodide (PI) assay. To assess the type of cell death induced in HL-60, the cell cycle, morphological, and biochemical alterations were analyzed, which were determined by differential staining with acridine orange/ethidium bromide, and annexin V/PI double-labeling and change in mitochondrial membrane potential assays. Curine demonstrated a potent cytotoxic effect on leukemic cell lines (HL-60 and K562). Its cytotoxic effects in HL-60 cells was related to plasma membrane damage and cell cycle arrest at the G1 phase from 43.4 ± 1.0 to 56.7 ± 1.4 % (p < 0.05). Curine (15 μM) also increased the apoptotic cells number by around 60 % in HL-60 cells and caused phosphatidylserine externalization, inducing about 57 % of apoptosis. Moreover, this alkaloid provoked 20 % of mitochondrial membrane depolarization. We conclude that curine presented a cytotoxic effect and induced apoptosis in HL-60 cells. Thus, it can be considered a promising pharmacological drug.

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

    PubMed

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

    2015-01-01

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

  19. 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.

  20. Nucleolar asymmetry and the importance of septin integrity upon cell cycle arrest

    PubMed Central

    Rai, Urvashi; Najm, Fadi

    2017-01-01

    Cell cycle arrest can be imposed by inactivating the anaphase promoting complex (APC). In S. cerevisiae this arrest has been reported to stabilize a metaphase-like intermediate in which the nuclear envelope spans the bud neck, while chromatin repeatedly translocates between the mother and bud domains. The present investigation was undertaken to learn how other features of nuclear organization are affected upon depletion of the APC activator, Cdc20. We observe that the spindle pole bodies and the spindle repeatedly translocate across the narrow orifice at the level of the neck. Nevertheless, we find that the nucleolus (organized around rDNA repeats on the long right arm of chromosome XII) remains in the mother domain, marking the polarity of the nucleus. Accordingly, chromosome XII is polarized: TelXIIR remains in the mother domain and its centromere is predominantly located in the bud domain. In order to learn why the nucleolus remains in the mother domain, we studied the impact of inhibiting rRNA synthesis in arrested cells. We observed that this fragments the nucleolus and that these fragments entered the bud domain. Taken together with earlier observations, the restriction of the nucleolus to the mother domain therefore can be attributed to its massive structure. We also observed that inactivation of septins allowed arrested cells to complete the cell cycle, that the alternative APC activator, Cdh1, was required for completion of the cell cycle and that induction of Cdh1 itself caused arrested cells to progress to the end of the cell cycle. PMID:28339487

  1. The long non-coding RNA GAS5 differentially regulates cell cycle arrest and apoptosis through activation of BRCA1 and p53 in human neuroblastoma

    PubMed Central

    Mazar, Joseph; Rosado, Amy; Shelley, John; Marchica, John; Westmoreland, Tamarah J

    2017-01-01

    The long non-coding RNA GAS5 has been shown to modulate cancer proliferation in numerous human cancer systems and has been correlated with successful patient outcome. Our examination of GAS5 in neuroblastoma has revealed robust expression in both MYCN-amplified and non-amplified cell lines. Knockdown of GAS5 In vitro resulted in defects in cell proliferation, apoptosis, and induced cell cycle arrest. Further analysis of GAS5 clones revealed multiple novel splice variants, two of which inversely modulated with MYCN status. Complementation studies of the variants post-knockdown of GAS5 indicated alternate phenotypes, with one variant (FL) considerably enhancing cell proliferation by rescuing cell cycle arrest and the other (C2) driving apoptosis, suggesting a unique role for each in neuroblastoma cancer physiology. Global sequencing and ELISA arrays revealed that the loss of GAS5 induced p53, BRCA1, and GADD45A, which appeared to modulate cell cycle arrest in concert. Complementation with only the FL GAS5 clone could rescue cell cycle arrest, stabilizing HDM2, and leading to the loss of p53. Together, these data offer novel therapeutic targets in the form of lncRNA splice variants for separate challenges against cancer growth and cell death. PMID:28035057

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

    PubMed Central

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

    2016-01-01

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

  3. 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.

  4. Lipid biomarkers of glioma cell growth arrest and cell death detected by 1 H magic angle spinning MRS.

    PubMed

    Mirbahai, Ladan; Wilson, Martin; Shaw, Christopher S; McConville, Carmel; Malcomson, Roger D G; Kauppinen, Risto A; Peet, Andrew C

    2012-11-01

    Biomarkers of early response to treatment have the potential to improve cancer therapy by allowing treatment to be tailored to the individual. Alterations in lipids detected by in vivo MRS have been suggested as noninvasive biomarkers of cell stress and early indicators of cell death. An improved understanding of the relationship between MRS lipids and cell stress in vitro would aid in the translation of this technique into clinical use. Rat BT4C glioma cells were treated with 50 µ m cis-dichlorodiammineplatinum II (cisplatin), a commonly used chemotherapeutic agent, and harvested at several time points up to 72 h. High-resolution magic angle spinning (1) H MRS of cells was then performed on a 600-MHz NMR spectrometer. The metabolites were quantified using a time domain fitting method, TARQUIN. Increases were detected in saturated and polyunsaturated fatty acid resonances early during the exposure to cisplatin. The fatty acid CH(2) /CH(3) ratio was unaltered by treatment after allowing for contributions of macromolecules. Polyunsaturated fatty acids increased on treatment, with the group -CH=CH-CH(2) -CH=CH- accounting for all the unsaturated fatty acid signals. Transmission electron microscopy, in addition to Nile red and 4',6-diamino-2-phenylindole co-staining, revealed that the lipid increase was associated with cytoplasmic neutral lipid droplets. Small numbers of apoptotic and necrotic cells were detected by trypan blue, annexin V-fluorescein isothiocyanate-labelled flow cytometry and DNA laddering after up to 48 h of cisplatin exposure. Propidium iodide flow cytometry revealed that cells accumulated in the G1 stage of the cell growth cycle. In conclusion, an increase in the size of the lipid droplets is detected in morphologically viable cells during cisplatin exposure. (1) H MRS can detect lipid alterations during cell cycle arrest and progression of cell death, and has the potential to provide a noninvasive biomarker of treatment efficacy in vivo.

  5. Cell cycle arrest in a model of colistin nephrotoxicity

    PubMed Central

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

    2013-01-01

    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. PMID:23922129

  6. Cell Cycle Regulators and Cell Death in Immunity

    PubMed Central

    Zebell, Sophia G.; Dong, Xinnian

    2015-01-01

    Summary Various cell death mechanisms are integral to host defense in both plants and mammals. Plant defense against biotrophic pathogens is associated with programmed cell death (PCD) of the infected cell. This effector-triggered PCD is partly analogous to pyroptosis, an inflammatory host cell death process that plays a crucial role in defense against microbial infections in mammals. Plant effector-triggered PCD also shares with mammalian apoptosis the involvement of cell cycle regulators as signaling components. Here we explore the similarities between these different cell death programs as they relate to host defense and their relationship to the cell-cycle. PMID:26468745

  7. AMPK Causes Cell Cycle Arrest in LKB1-deficient Cells via Activation of CAMKK2

    PubMed Central

    Fogarty, Sarah; Ross, Fiona A.; Ciruelos, Diana Vara; Gray, Alexander; Gowans, Graeme J.; Hardie, D. Grahame

    2017-01-01

    The AMP-activated protein kinase (AMPK) is activated by phosphorylation at Thr172, either by the tumor suppressor kinase LKB1 or by an alternate pathway involving the Ca2+/calmodulin-dependent kinase, CAMKK2. Increases in AMP:ATP and ADP:ATP ratios, signifying energy deficit, promote allosteric activation and net Thr172 phosphorylation mediated by LKB1, so that the LKB1-AMPK pathway acts as an energy sensor. Many tumor cells carry loss-of-function mutations in the STK11 gene encoding LKB1, but LKB1 re-expression in these cells causes cell cycle arrest. Therefore, it was investigated as to whether arrest by LKB1 is caused by activation of AMPK or of one of the AMPK-related kinases, which are also dependent on LKB1 but are not activated by CAMKK2. In three LKB1-null tumor cell lines, treatment with the Ca2+ ionophore A23187 caused a G1-arrest that correlated with AMPK activation and Thr172 phosphorylation. In G361 cells, expression of a truncated, CAMKK2 mutant also caused G1-arrest similar to that caused by expression of LKB1, while expression of a dominant negative AMPK mutant, or a double knockout of both AMPK-α subunits, also prevented the cell cycle arrest caused by A23187. These mechanistic findings confirm that AMPK activation triggers cell cycle arrest, and also suggest that the rapid proliferation of LKB1-null tumor cells is due to lack of the restraining influence of AMPK. However, cell cycle arrest can be restored by re-expressing LKB1 or a constitutively active CAMKK2, or by pharmacological agents that increase intracellular Ca2+ and thus activate endogenous CAMKK2. Implications Evidence here reveals that the rapid growth and proliferation of cancer cells lacking the tumor suppressor LKB1 is due to reduced activity of AMPK, and suggests a therapeutic approach by which this block might be circumvented. PMID:27141100

  8. Cardiac arrest triggers hippocampal neuronal death through autophagic and apoptotic pathways

    PubMed Central

    Cui, Derong; Shang, Hanbing; Zhang, Xiaoli; Jiang, Wei; Jia, Xiaofeng

    2016-01-01

    The mechanism of neuronal death induced by ischemic injury remains unknown. We investigated whether autophagy and p53 signaling played a role in the apoptosis of hippocampal neurons following global cerebral ischemia-reperfusion (I/R) injury, in a rat model of 8-min asphyxial cardiac arrest (CA) and resuscitation. Increased autophagosome numbers, expression of lysosomal cathepsin B, cathepsin D, Beclin-1, and microtubule-associated protein light chain 3 (LC3) suggested autophagy in hippocampal cells. The expression of tumor suppressor protein 53 (p53) and its target genes: Bax, p53-upregulated modulator of apoptosis (PUMA), and damage-regulated autophagy modulator (DRAM) were upregulated following CA. The p53-specific inhibitor pifithrin-α (PFT-α) significantly reduced the expression of pro-apoptotic proteins (Bax and PUMA) and autophagic proteins (LC3-II and DRAM) that generally increase following CA. PFT-α also reduced hippocampal neuronal damage following CA. Similarly, 3-methyladenine (3-MA), which inhibits autophagy and bafilomycin A1 (BFA), which inhibits lysosomes, significantly inhibited hippocampal neuronal damage after CA. These results indicate that CA affects both autophagy and apoptosis, partially mediated by p53. Autophagy plays a significant role in hippocampal neuronal death induced by cerebral I/R following asphyxial-CA. PMID:27273382

  9. Unexpected Arrest-Related Deaths in America: 12 Months of Open Source Surveillance

    PubMed Central

    Ho, Jeffrey D.; Heegaard, William G.; Dawes, Donald M.; Natarajan, Sridhar; Reardon, Robert F.; Miner, James R.

    2009-01-01

    Introduction: Sudden, unexpected arrest-related death (ARD) has been associated with drug abuse, extreme delirium or certain police practices. There is insufficient surveillance and causation data available. We report 12 months of surveillance data using a novel data collection methodology. Methods: We used an open-source, prospective method to collect 12 consecutive months of data, including demographics, behavior, illicit substance use, control methods used, and time of collapse after law enforcement contact. Descriptive analysis and chi-square testing were applied. Results: There were 162 ARD events reported that met inclusion criteria. The majority were male with mean age 36 years, and involved bizarre, agitated behavior and reports of drug abuse just prior to death. Law enforcement control techniques included none (14%); empty-hand techniques (69%); intermediate weapons such as TASER® device, impact weapon or chemical irritant spray (52%); and deadly force (12%). Time from contact to subject collapse included instantaneous (13%), within the first hour (53%) and 1–48 hours (35%). Significant collapse time associations occurred with the use of certain intermediate weapons. Conclusion: This surveillance report can be a foundation for discussing ARD. These data support the premise that ARDs primarily occur in persons with a certain demographic and behavior profile that includes middle-aged males exhibiting agitated, bizarre behavior generally following illicit drug abuse. Collapse time associations were demonstrated with the use of TASER devices and impact weapons. We recommend further study in this area to validate our data collection method and findings. PMID:19561821

  10. 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.

  11. 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.

  12. 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

  13. 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

  14. Jatamanvaltrate P induces cell cycle arrest, apoptosis and autophagy in human breast cancer cells in vitro and in vivo.

    PubMed

    Yang, Bo; Zhu, Rui; Tian, Shasha; Wang, Yiqi; Lou, Siyue; Zhao, Huajun

    2017-03-10

    Jatamanvaltrate P is a novel iridoid ester isolated from Valeriana jatamansi Jones, a traditional medicine used to treat nervous disorders. In this study, we found that Jatamanvaltrate P possessed notable antitumor properties and therefore evaluated its anticancer effects against human breast cancer cells in vitro and in vivo. Jatamanvaltrate P inhibited the growth and proliferation of MCF-7 and triple-negative breast cancer (TNBC) cell lines (MDA-MB-231, MDA-MB-453 and MDA-MB-468) in a concentration-dependent manner, while displayed relatively low cytotoxicity to human breast epithelial cells (MCF-10A). Treatment with Jatamanvaltrate P induced G2/M-phase arrest in TNBC and G0/G1-phase arrest in MCF-7 cells. Further study of the molecular mechanisms of this cytotoxic compound demonstrated that Jatamanvaltrate P enhanced cleavage of PARP and caspases, while decreased the expression levels of cell cycle-related Cyclin B1, Cyclin D1 and Cdc-2. It also activated autophagy, as indicated by the triggered autophagosome formation and increased LC3-II levels. Autophagy inhibition by 3-MA co-treatment undermined Jatamanvaltrate P-induced cell death. Finally, Jatamanvaltrate P exhibited a potential antitumor effect in MDA-MB-231 xenografts without apparent toxicity. These results suggest that Jatamanvaltrate P is a potential therapeutic agent for breast cancer, providing a basis for development of the compound as a novel chemotherapeutic agent.

  15. Hispolon from Phellinus linteus induces G0/G1 cell cycle arrest and apoptosis in NB4 human leukaemia cells.

    PubMed

    Chen, Yi-Chuan; Chang, Heng-Yuan; Deng, Jeng-Shyan; Chen, Jian-Jung; Huang, Shyh-Shyun; Lin, I-Hsin; Kuo, Wan-Lin; Chao, Wei; Huang, Guan-Jhong

    2013-01-01

    Hispolon (a phenolic compound isolated from Phellinus linteus) has been shown to possess strong antioxidant, anti-inflammatory, anticancer, and antidiabetic properties. In this study, we investigated the antiproliferative effect of hispolon on human hepatocellular carcinoma NB4 cells using the MTT assay, DNA fragmentation, DAPI (4, 6-diamidino-2-phenylindole dihydrochloride) staining, and flow cytometric analysis. Hispolon inhibited the cellular growth of NB4 cells in a dose-dependent manner through the induction of cell cycle arrest at G0/G1 phase measured using flow cytometric analysis and apoptotic cell death, as demonstrated by DNA laddering. Exposure of NB4 cells to hispolon-induced apoptosis-related protein expressions, such as the cleavage form of caspase 3, caspase 8, caspase 9, poly (ADP ribose) polymerase, and the proapoptotic Bax protein. Western blot analysis showed that the protein levels of extrinsic apoptotic proteins (Fas and FasL), intrinsic related proteins (cytochrome c), and the ratio of Bax/Bcl-2 were increased in NB4 cells after hispolon treatment. Hispolon-induced G0/G1-phase arrest was associated with a marked decrease in the protein expression of p53, cyclins D1, and cyclins E, and cyclin-dependent kinases (CDKs) 2, and 4, with concomitant induction of p21waf1/Cip1 and p27Kip1. We conclude that hispolon induces both of extrinsic and intrinsic apoptotic pathways in NB4 human leukemia cells in vitro.

  16. A non-death role of the yeast metacaspase: Yca1p alters cell cycle dynamics.

    PubMed

    Lee, Robin E C; Puente, Lawrence G; Kaern, Mads; Megeney, Lynn A

    2008-08-13

    Caspase proteases are a conserved protein family predominantly known for engaging and executing apoptotic cell death. Nevertheless, in higher eukaryotes, caspases also influence a variety of cell behaviors including differentiation, proliferation and growth control. S. cerevisiae expresses a primordial caspase, yca1, and exhibits apoptosis-like death under certain stresses; however, the benefit of a dedicated death program to single cell organisms is controversial. In the absence of a clear rationale to justify the evolutionary retention of a death only pathway, we hypothesize that yca1 also influences non-apoptotic events. We report that genetic ablation and/or catalytic inactivation of Yca1p leads to a longer G1/S transition accompanied by slower growth in fermentation conditions. Downregulation of Yca1p proteolytic activity also results in failure to arrest during nocodazole treatment, indicating that Yca1p participates in the G2/M mitotic checkpoint. 20s proteasome activity and ROS staining of the Delta yca1 strain is indistinguishable from its isogenic control suggesting that putative regulation of the oxidative stress response by Yca1p does not instigate the cell cycle phenotype. Our results demonstrate multiple non-death roles for yca1 in the cell cycle.

  17. Myricetin inhibits proliferation and induces apoptosis and cell cycle arrest in gastric cancer cells.

    PubMed

    Feng, Jianfang; Chen, Xiaonan; Wang, Yuanyuan; Du, Yuwen; Sun, Qianqian; Zang, Wenqiao; Zhao, Guoqiang

    2015-10-01

    Myricetin is a flavonoid that is abundant in fruits and vegetables and has protective effects against cancer and diabetes. However, the mechanism of action of myricetin against gastric cancer (GC) is not fully understood. We researched myricetin on the proliferation, apoptosis, and cell cycle in GC HGC-27 and SGC7901 cells, to explore the underlying mechanism of action. Cell Counting Kit (CCK)-8 assay, Western blotting, cell cycle analysis, and apoptosis assay were used to evaluate the effects of myricetin on cell proliferation, apoptosis, and the cell cycle. To analyze the binding properties of ribosomal S6 kinase 2 (RSK2) with myricetin, surface plasmon resonance (SPR) analysis was performed. CCK8 assay showed that myricetin inhibited GC cell proliferation. Flow cytometry analysis showed that myricetin induces apoptosis and cell cycle arrest in GC cells. Western blotting indicated that myricetin influenced apoptosis and cell cycle arrest of GC cells by regulating related proteins. SPR analysis showed strong binding affinity of RSK2 and myricetin. Myricetin bound to RSK2, leading to increased expression of Mad1, and contributed to inhibition of HGC-27 and SGC7901 cell proliferation. Our results suggest the therapeutic potential of myricetin in GC.

  18. Mefloquine inhibits chondrocytic proliferation by arresting cell cycle in G2/M phase.

    PubMed

    Li, Qiong; Chen, Zeng-Gan; Xia, Qing; Lin, Jian-Ping; Yan, Zuo-Qin; Yao, Zheng-Jun; Dong, Jian

    2015-01-01

    Mefloquine (MQ), an analog of chloroquine, exhibits a promising cytotoxic activity against carcinoma cell lines and for the treatment of glioblastoma patients. The present study demonstrates the effect of mefloquine on proliferation and cell cycle in chondrocytes. MTT assay and propidium iodide staining were used for the analysis of proliferation and cell cycle distribution, respectively. Western blot analysis was used to examine the expression levels of cyclin B1/cdc2, cdc25c, p21WAF1/CIP1 and p53. The results revealed that mefloquine inhibited the proliferation of chondrocytes and caused cell cycle arrests in the G2/M phase. The proliferation of chondrocytes was reduced to 27% at 40 μM concentration of mefloquine after 48 h. The population of chondrocytes in G2/M phase was found to be 15.7 and 48.4%, respectively at 10 and 40 μM concentration of mefloquine at 48 h following treatment. The expression of the cell cycle regulatory proteins including, cyclin B1/cdc2 and cdc25c was inhibited. On the other hand, mefloquine treatment promoted the expression of p21WAF1/CIP1 and p53 at 40 μM concentration after 48 h. Therefore, mefloquine inhibits proliferation and induces cell cycle arrest in chondrocytes.

  19. 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

  20. 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.

  1. Natural Compounds as Modulators of Cell Cycle Arrest: Application for Anticancer Chemotherapies.

    PubMed

    Bailon-Moscoso, Natalia; Cevallos-Solorzano, Gabriela; Romero-Benavides, Juan Carlos; Orellana, Maria Isabel Ramirez

    2017-04-01

    Natural compounds from various plants, microorganisms and marine species play an important role in the discovery novel components that can be successfully used in numerous biomedical applications, including anticancer therapeutics. Since uncontrolled and rapid cell division is a hallmark of cancer, unraveling the molecular mechanisms underlying mitosis is key to understanding how various natural compounds might function as inhibitors of cell cycle progression. A number of natural compounds that inhibit the cell cycle arrest have proven effective for killing cancer cells in vitro, in vivo and in clinical settings. Significant advances that have been recently made in the understanding of molecular mechanisms underlying the cell cycle regulation using the chemotherapeutic agents is of great importance for improving the efficacy of targeted therapeutics and overcoming resistance to anticancer drugs, especially of natural origin, which inhibit the activities of cyclins and cyclin-dependent kinases, as well as other proteins and enzymes involved in proper regulation of cell cycle leading to controlled cell proliferation.

  2. 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.

  3. 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.

  4. 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

  5. Variant surface glycoprotein RNA interference triggers a precytokinesis cell cycle arrest in African trypanosomes.

    PubMed

    Sheader, Karen; Vaughan, Sue; Minchin, James; Hughes, Katie; Gull, Keith; Rudenko, Gloria

    2005-06-14

    Trypanosoma brucei is a protozoan parasite that causes African sleeping sickness. T. brucei multiplies extracellularly in the bloodstream, relying on antigenic variation of a dense variant surface glycoprotein (VSG) coat to escape antibody-mediated lysis. We investigated the role of VSG in proliferation and pathogenicity by using inducible RNA interference to ablate VSG transcript down to 1-2% normal levels. Inhibiting VSG synthesis in vitro triggers a rapid and specific cell cycle checkpoint blocking cell division. Parasites arrest at a discrete precytokinesis stage with two full-length flagella and opposing flagellar pockets, without undergoing additional rounds of S phase and mitosis. A subset (<10%) of the stalled cells have internal flagella, indicating that the progenitors of these cells were already committed to cytokinesis when VSG restriction was sensed. Although there was no obvious VSG depletion in vitro after 24-h induction of VSG RNA interference, there was rapid clearance of these cells in vivo. We propose that a stringent block in VSG synthesis produces stalled trypanosomes with a minimally compromised VSG coat, which can be targeted by the immune system. Our data indicate that VSG protein or transcript is monitored during cell cycle progression in bloodstream-form T. brucei and describes precise precytokinesis cell cycle arrest. This checkpoint before cell division provides a link between the protective VSG coat and cell cycle progression and could function as a novel parasite safety mechanism, preventing extensive dilution of the protective VSG coat in the absence of VSG synthesis.

  6. Ibuprofen and apigenin induce apoptosis and cell cycle arrest in activated microglia.

    PubMed

    Elsisi, Nahed S; Darling-Reed, Selina; Lee, Eunsook Y; Oriaku, Ebenezer T; Soliman, Karam F

    2005-02-28

    In case of injury or disease, microglia are recruited to the site of the pathology and become activated as evidenced by morphological changes and expression of pro-inflammatory cytokines. Evidence suggests that microglia proliferate by cell division to create gliosis at the site of pathological conditions such as the amyloid plaques in Alzheimer's disease and the substantia nigra of Parkinson's disease patients. The hyperactivation of microglia contributes to neurotoxicity. In the present study we tested the hypothesis that anti-inflammatory compounds modulate the progression of cell cycle and induce apoptosis of the activated cells. We investigated the effects of ibuprofen (non-steroidal anti-inflammatory drug) and apigenin (a flavonoid with anti-inflammatory and anti-proliferative properties) on the cell cycle of the murine microglial cell line BV-2. The findings indicate that apigenin-induced cell cycle arrest preferentially in the G2/M phase and ibuprofen caused S phase arrest. The binding of annexin V-FITC to the membranes of cells which indicates the apoptotic process were examined, whereas the DNA was stained with propidium iodide. Both apigenin and ibuprofen induced apoptosis significantly in early and late stages. The induction of apoptosis by ibuprofen and apigenin was confirmed using TUNEL assay, revealing that 25 microM apigenin and 250 microM ibuprofen significantly increased apoptosis in BV-2 cells. The results from the present study suggest that anti-inflammatory compounds might inhibit microglial proliferation by modulating the cell cycle progression and apoptosis.

  7. 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

  8. Role of NF-κB-p53 crosstalk in ultraviolet A-induced cell death and G1 arrest in human dermal fibroblasts.

    PubMed

    Lee, Yun Kyung; Cha, Hwa Jun; Hong, Misun; Yoon, Yeongmin; Lee, Hyunjin; An, Sungkwan

    2012-01-01

    Photoaging is the premature aging of the skin caused by repeated exposure to sunlight and is characterized by a depletion of the dermal extracellular matrix. This depletion is due to the loss of fibroblast cells and their multiple functions. UVA was revealed as a major inducer of photoaging in various clinical studies. As UVA photons have long wavelength spectra, UVA penetrates deeper into the dermis than UVB and UVC, leading to the induction of cell death, the destruction of the dermal extracellular matrix through the induction of matrix metalloproteinase expression, and the repression of collagen expression. However, the exact effects of UVA on the skin remain a matter of debate. Here, we assess cell cycle stage to demonstrate that NF-κB-p53 crosstalk induces apoptosis and growth arrest in UVA-irradiated human dermal fibroblasts. In addition, UVA irradiation led to an increase of NF-κB-HDAC1 complexes, which in turn repressed cyclin D1 expression in UVA-irradiated human dermal fibroblasts. We provide direct evidence that UVA irradiation induces changes in the p53-dependent NF-κB complex that lead to growth arrest and apoptosis through the repression of cyclin D1. These studies uncovered that NF-κB-p53 crosstalk is a key regulator of UVA-dependent growth arrest and apoptosis.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. Lipid-soluble ginseng extract induces apoptosis and G0/G1 cell cycle arrest in NCI-H460 human lung cancer cells.

    PubMed

    Kang, Moo Rim; Kim, Hwan Mook; Kang, Jong Soon; Lee, Kiho; Lee, Sung Dong; Hyun, Dong-Hoon; In, Man-Jin; Park, Song-Kyu; Kim, Dong Chung

    2011-06-01

    This study was performed to elucidate the anticancer mechanism of a lipid-soluble ginseng extract (LSGE) by analyzing induction of apoptosis and arrest of cell cycle progression using the NCI-H460 human lung cancer cell line. Proliferation of NCI-H460 cells was potently inhibited by LSGE in a dose-dependent manner. The cell cycle arrest at the G0/G1 phase in NCI-H460 cells was induced by LSGE. The percentage of G0/G1 phase cells significantly increased, while that of S phase cells decreased after treatment with LSGE. The expression levels of cyclin-dependent kinase2 (CDK2), CDK4, CDK6, cyclin D3 and cyclin E related to G0/G1 cells progression were also altered by LSGE. In addition, LSGE-induced cell death occurred through apoptosis, which was accompanied by increasing the activity of caspases including caspase-8, caspase-9 and caspase-3. Consistent with enhancement of caspase activity, LSGE increased protein levels of cleaved caspase-3, caspase-8, caspase-9, and poly-ADP-ribose polymerase (PARP). These apoptotic effects of LSGE were inhibited by the pan-caspase inhibitor Z-VAD-fmk. These findings indicate that LSGE inhibits NCI-H460 human lung cancer cell growth by cell cycle arrest at the G0/G1 phase and induction of caspase-mediated apoptosis.

  14. 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

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

    PubMed

    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 Ser(473) and Thr(308); through the suppression of mTOR and pPDK1 respectively. As a consequence of this, diminished phosphorylation of Bad occurred along with the decreased Bcl-xL expression. This subsequently enhanced Bax levels permitting the release of mitochondrial cytochrome c into the cytosol which concomitantly activated caspase 9 and caspase 3 resulting apoptotic cell death. Impairment of Akt activation by VCO also deactivated Mdm2 that effected overexpression of p53 which in turn upregulated p21 expression. This causes enhanced p21 binding to cyclin D1 that halted G1 to S phase progression. Taken together, VCO produces two prong effects on lung cancer cells, it induces apoptosis and blocked cancer cell proliferation, both occurred due to the deactivation of Akt. In addition, it has another crucial advantage: VCO could be directly delivered to lung cancer tissue through inhalation.

  16. 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

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

    PubMed Central

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

    2006-01-01

    AIM: To investigate the relationship between the inhibited growth (cytotoxic activity) of berberine and apoptotic pathway with its molecular mechanism of action. METHODS: The in vitro cytotoxic techniques were complemented by cell cycle analysis and determination of sub-G1 for apoptosis in human gastric carcinoma SNU-5 cells. Percentage of viable cells, cell cycle, and sub-G1 group (apoptosis) were examined and determined by the flow cytometric methods. The associated proteins for cell cycle arrest and apoptosis were examined by Western blotting. RESULTS: For SNU-5 cell line, the IC (50) was found to be 48 μmol/L of berberine. In SNU-5 cells treated with 25-200 μmol/L berberine, G2/M cell cycle arrest was observed which was associated with a marked increment of the expression of p53, Wee1 and CDk1 proteins and decreased cyclin B. A concentration-dependent decrease of cells in G0/G1 phase and an increase in G2/M phase were detected. In addition, apoptosis detected as sub-G0 cell population in cell cycle measurement was proved in 25-200 μmol/L berberine-treated cells by monitoring the apoptotic pathway. Apoptosis was identified by sub-G0 cell population, and upregulation of Bax, downregulation of Bcl-2, release of Ca2+, decreased the mitochondrial membrane potential and then led to the release of mitochondrial cytochrome C into the cytoplasm and caused the activation of caspase-3, and finally led to the occurrence of apoptosis. CONCLUSION: Berberine induces p53 expression and leads to the decrease of the mitochondrial membrane potential, Cytochrome C release and activation of caspase-3 for the induction of apoptosis. PMID:16440412

  18. Schisandrin B inhibits the proliferation of human lung adenocarcinoma A549 cells by inducing cycle arrest and apoptosis

    PubMed Central

    Lv, Xue-Jiao; Zhao, Li-Jing; Hao, Yu-Qiu; Su, Zhen-Zhong; Li, Jun-Yao; Du, Yan-Wei; Zhang, Jie

    2015-01-01

    Lung cancer is the leading cause of cancer death in the world. Schizandrin B (Sch B) is one of the main dibenzocyclooctadiene lignans present in the fruit of Schisandra chinensis (Schisandraceae). Sch B has multiple functions against cancer. The aim of this study was to determine the effect of Sch B on the proliferation, cell cycling, apoptosis and invasion of lung adenocarcinoma A549 cells by MTT, flow cytometry, wound healing and transwell invasion assays. Treatment with Sch B inhibited the proliferation of A549 cells in a dose-dependent manner. Sch B induced cell cycle arrest at G0/G1 phase by down-regulating the expression of cyclin D1, cyclin-dependent kinase (CDK)4, and CDK6, but up-regulating p53 and p21 expression in A549 cells. Furthermore, Sch B triggered A549 cell apoptosis by increasing Bax, cleaved caspase-3, 9, Cyto C, but decreasing Bcl-2 and PCNA expression. In addition, Sch B inhibited the invasion and migration of A549 cells by down-regulating the expressions of HIF-1, VEGF, MMP-9 and MMP-2. Therefore, Sch B has potent anti-tumor activity and may be a promising traditional Chinese medicine for human lung carcinoma. PMID:26221229

  19. 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

  20. Caudatin Inhibits Human Glioma Cells Growth Through Triggering DNA Damage-Mediated Cell Cycle Arrest.

    PubMed

    Fu, Xiao-yan; Zhang, Shuai; Wang, Kun; Yang, Ming-feng; Fan, Cun-dong; Sun, Bao-liang

    2015-10-01

    Caudatin, one of the species of C-21 steroidal glycosides mainly isolated from the root of Cynanchum bungei Decne, exhibits potent anticancer activities. However, the mechanism remains poorly defined. In the present study, the growth inhibitory effect and mechanism of caudatin on human glioma cells were evaluated in vitro. The results revealed that caudatin time- and dose-dependently inhibited U251 and U87 cells growth. Flow cytometry analysis indicated that caudatin-induced growth inhibition against U251 and U87 cells was mainly achieved by the induction of G0/G1 and S-phase cell cycle arrest through triggering DNA damage, as convinced by the up-regulation of p53, p21, and histone phosphorylation, as well as the down-regulation of cyclin D1. Moreover, caudatin treatment also triggered the activation of ERK and inactivation of AKT pathway. LY294002 (an AKT inhibitor) addition enhanced caudation-induced AKT inhibition, indicating that caudatin inhibited U251 cells growth in an AKT-dependent manner. Taken together, these results indicate that caudatin may act as a novel cytostatic reagent against human glioma cells through the induction of DNA damage-mediated cell cycle arrest with the involvement of modulating MAPK and AKT pathways.

  1. Isoalantolactone inhibits UM-SCC-10A cell growth via cell cycle arrest and apoptosis induction.

    PubMed

    Wu, Minjun; Zhang, Hua; Hu, Jiehua; Weng, Zhiyong; Li, Chenyuan; Li, Hong; Zhao, Yan; Mei, Xifan; Ren, Fu; Li, Lihua

    2013-01-01

    Isoalantolactone is a sesquiterpene lactone compound isolated from the roots of Inula helenium L. Previous studies have demonstrated that isoalantolactone possesses antifungal, anti-bacterial, anti-helminthic and anti-proliferative properties in a variety of cells, but there are no studies concerning its effects on head and neck squamous cell carcinoma (HNSCC). In the present study, an MTT assay demonstrated that isoalantolactone has anti-proliferative activity against the HNSCC cell line (UM-SCC-10A). Immunostaining identified that this compound induced UM-SCC-10A cell apoptosis but not necrosis. To explain the molecular mechanisms underlying its effects, flow cytometry and western blot analysis showed that the apoptosis was associated with cell cycle arrest during the G1 phase, up-regulation of p53 and p21, and down-regulation of cyclin D. Furthermore, our results revealed that induction of apoptosis through a mitochondrial pathway led to up-regulation of pro-apoptotic protein expression (Bax), down-regulation of anti-apoptotic protein expression (Bcl-2), mitochondrial release of cytochrome c (Cyto c), reduction of mitochondrial membrane potential (MMP) and activation of caspase-3 (Casp-3). Involvement of the caspase apoptosis pathway was confirmed using caspase inhibitor Z-VAD-FMK pretreatment. Together, our findings suggest that isoalantolactone induced caspase-dependent apoptosis via a mitochondrial pathway and was associated with cell cycle arrest in the G1 phase in UM-SCC-10A cells. Therefore, isoalantolactone may become a potential drug for treating HNSCC.

  2. Cimicifuga foetida extract inhibits proliferation of hepatocellular cells via induction of cell cycle arrest and apoptosis.

    PubMed

    Tian, Ze; Pan, Ruile; Chang, Qi; Si, Jianyong; Xiao, Peigen; Wu, Erxi

    2007-11-01

    The purpose of this study is to determine whether the ethyl acetate fraction (EAF) from the aerial part of Cimicifuga foetida Linnaeus possesses the anti-tumor action on hepatoma, and therefore, provide evidence for the traditional use of the plant as a detoxification agent. EAF was extracted and its cytotoxicity was evaluated on a panel of Hepatocytes by MTT assay. The IC(50) values of EAF on HepG2, R-HepG2 and primary cultured normal mouse hepatocytes were 21, 43 and 80 microg/mL, respectively. Morphology observation, Annexin V-FITC/PI staining, cell cycle analysis and western blot were used to further elucidate the cytotoxic mechanism of EAF. EAF induced G(0)/G(1)cell cycle arrest at lower concentration (25 microg/mL), and triggered G(2)/M arrest and apoptosis at higher concentrations (50 and 100 microg/mL, respectively). An increase in the ratio of Bax/Bcl-2, activation of downstream effector Caspase 3, and cleavage of poly-ADP-ribose polymerase (PARP) were implicated in EAF-induced apoptosis. In addition, EAF inhibited the growth of the implanted mouse H(22) tumor in a dose-dependent manner with the growth inhibitory rate of 63.32% at 200 mg/kg. In conclusion, EAF may potentially find use as a new therapy for the treatment of hepatoma.

  3. Enhanced radiation-induced cytotoxic effect by 2-ME in glioma cells is mediated by induction of cell cycle arrest and DNA damage via activation of ATM pathways.

    PubMed

    Zou, Huichao; Zhao, Shiguang; Zhang, Jianhua; Lv, Gongwei; Zhang, Xu; Yu, Hongwei; Wang, Huibo; Wang, Ligang

    2007-12-14

    Glioblastoma multiform is the most common malignant primary brain tumor in adults, but there remains no effective therapeutic approach. 2-methoxyestradiol (2-ME), which is a naturally occurring metabolite of 17beta-estradiol, was shown to enhance radiotherapeutic effect in certain tumors; however, whether 2-ME can also enhance the sensitivity of glioma cells to radiotherapy remains unknown. The present study, therefore, was to address this issue using two human glioma cell lines (T98G and U251MG). These cells were irradiated with and without 2-ME and then clonogenic assay, apoptosis assay, DNA damage, and cell cycle change were examined. Results showed that 2-ME significantly enhances radiation-induced cell death in both glioma cells, shown by decreasing cell viability and increasing apoptotic cell death. No such radiosensitizing effect was observed if cells pre-treated with Estrodiol, suggesting the specifically radiosensitizing effect of 2-ME rather than a general effect of estrodials. The enhanced radio-cytotoxic effect in glioma cells by 2-ME was found to be associated with its enhancement of G(2)/M arrest and DNA damage, and phosphorylated ATM protein kinases as well as cell cycle checkpoint protein Chk2. Furthermore, inhibition of ATM by ATM inhibitor abolished 2-ME-activated Chk2 and enhanced radio-cytotoxic effects. These results suggest that 2-ME enhancement of the sensitivity of glioma cell lines to radiotherapy is mediated by induction of G2/M cell cycle arrest and increased DNA damage via activation of ATM kinases.

  4. DC-SCRIPT is a novel regulator of the tumor suppressor gene CDKN2B and induces cell cycle arrest in ERα-positive breast cancer cells.

    PubMed

    Ansems, Marleen; Søndergaard, Jonas Nørskov; Sieuwerts, Anieta M; Looman, Maaike W G; Smid, Marcel; de Graaf, Annemarie M A; de Weerd, Vanja; Zuidscherwoude, Malou; Foekens, John A; Martens, John W M; Adema, Gosse J

    2015-02-01

    Breast cancer is one of the most common causes of cancer-related deaths in women. The estrogen receptor (ERα) is well known for having growth promoting effects in breast cancer. Recently, we have identified DC-SCRIPT (ZNF366) as a co-suppressor of ERα and as a strong and independent prognostic marker in ESR1 (ERα gene)-positive breast cancer patients. In this study, we further investigated the molecular mechanism on how DC-SCRIPT inhibits breast cancer cell growth. DC-SCRIPT mRNA levels from 190 primary ESR1-positive breast tumors were related to global gene expression, followed by gene ontology and pathway analysis. The effect of DC-SCRIPT on breast cancer cell growth and cell cycle arrest was investigated using novel DC-SCRIPT-inducible MCF7 breast cancer cell lines. Genome-wide expression profiling of DC-SCRIPT-expressing MCF7 cells was performed to investigate the effect of DC-SCRIPT on cell cycle-related gene expression. Findings were validated by real-time PCR in a cohort of 1,132 ESR1-positive breast cancer patients. In the primary ESR1-positive breast tumors, DC-SCRIPT expression negatively correlated with several cell cycle gene ontologies and pathways. DC-SCRIPT expression strongly reduced breast cancer cell growth in vitro, breast tumor growth in vivo, and induced cell cycle arrest. In addition, in the presence of DC-SCRIPT, multiple cell cycles related genes were differentially expressed including the tumor suppressor gene CDKN2B. Moreover, in 1,132 primary ESR1-positive breast tumors, DC-SCRIPT expression also correlated with CDKN2B expression. Collectively, these data show that DC-SCRIPT acts as a novel regulator of CDKN2B and induces cell cycle arrest in ESR1-positive breast cancer cells.

  5. Lipopolysaccharide treatment arrests the cell cycle of BV-2 microglial cells in G₁ phase and protects them from UV light-induced apoptosis.

    PubMed

    Kaneko, Yoko S; Ota, Akira; Nakashima, Akira; Nagasaki, Hiroshi; Kodani, Yu; Mori, Keiji; Nagatsu, Toshiharu

    2015-02-01

    We previously reported that an optimal dose of lipopolysaccharide (LPS) markedly extends the lifespan of murine primary-cultured microglia by suppressing cell death pathways. In this study, we investigated the effects of LPS pretreatment on UV light-induced apoptosis of cells from the microglial cell line BV-2. More than half of BV-2 cells were apoptotic, and procaspase-3 was cleaved into its active form at 3 h of UV irradiation. In contrast, in BV-2 cells treated with LPS for 24 h, UV irradiation caused neither apoptosis nor procaspase-3 cleavage. LPS treatment arrested the cell cycle in G1 phase and upregulated cyclin-dependent kinase inhibitor p21(Waf1/Cip1) and growth arrest and DNA damage-inducible (GADD) 45α in BV-2 cells. When p21(Waf1/Cip1) and GADD45α were knocked down by small interfering RNA, procaspase-3 was cleaved into its active form to induce apoptosis. Our findings suggest that LPS inhibits UV-induced apoptosis in BV-2 cells through arrest of the cell cycle in G1 phase by upregulation of p21(Waf1/Cip1) and GADD45α. Excessive activation of microglia may play a critical role in the exacerbation of neurodegeneration, therefore, normalizing the precise regulation of apoptosis may be a new strategy to prevent the deterioration caused by neurodegenerative disorders.

  6. 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.

  7. Cordyceps cicadae induces G2/M cell cycle arrest in MHCC97H human hepatocellular carcinoma cells: a proteomic study

    PubMed Central

    2014-01-01

    Background Cordyceps cicadae is a medicinal fungus that is often used for treating cancer. However, the anticancer mechanisms of C. cicadae are largely unknown. This study aims to investigate the anticancer mechanisms of C. cicadae against hepatocellular carcinoma cells in vitro using a proteomic approach. Methods Human hepatocellular carcinoma MHCC97H cells were treated with a water extract of C. cicadae (0, 100, 250, 500, and 1000 μg/mL) for 48 h and harvested for cell viability assays. The significant differences in protein expression between control and C. cicadae-treated cells were analyzed by two-dimensional gel-based proteomics coupled with matrix-assisted laser desorption ionization-time of flight mass spectrometry. Flow cytometry analysis was employed to investigate the cell cycle and cell death. The anticancer molecular mechanism was analyzed by whole proteome mapping. Results The water extract of C. cicadae (0, 100, 250, 500, and 1000 μg/mL) inhibited the growth of MHCC97H cells in a dose-dependent manner via G2/M phase cell cycle arrest with no evidence of apoptosis. Among the identified proteins with upregulated expression were dynactin subunit 2, N-myc downstream-regulated gene 1, heat shock protein beta-1, alpha-enolase isoform 1, phosphatidylinositol transfer protein, and WD repeat-containing protein 1. Meanwhile, the proteins with downregulated expression were 14-3-3 gamma, BUB3, microtubule-associated protein RP/EB family member 1, thioredoxin-like protein, chloride intracellular channel protein 1, ectonucleoside triphosphate diphosphohydrolase 5, xaa-Pro dipeptidase, enoyl-CoA delta isomerase 1, protein-disulfide isomerase-related chaperone Erp29, hnRNP 2H9B, peroxiredoxin 1, WD-40 repeat protein, and serine/threonine kinase receptor-associated protein. Conclusion The water extract of C. cicadae reduced the growth of human hepatocellular carcinoma MHCC97H cells via G2/M cell cycle arrest. PMID:24872842

  8. 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.

  9. 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

  10. ECPR for Refractory Out-Of-Hospital Cardiac Arrest

    ClinicalTrials.gov

    2017-02-22

    Cardiac Arrest; Heart Arrest; Sudden Cardiac Arrest; Cardiopulmonary Arrest; Death, Sudden, Cardiac; Cardiopulmonary Resuscitation; CPR; Extracorporeal Cardiopulmonary Resuscitation; Extracorporeal Membrane Oxygenation

  11. 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.

  12. Evaluation of cell cycle arrest in estrogen responsive MCF-7 breast cancer cells: pitfalls of the MTS assay.

    PubMed

    McGowan, Eileen M; Alling, Nikki; Jackson, Elise A; Yagoub, Daniel; Haass, Nikolas K; Allen, John D; Martinello-Wilks, Rosetta

    2011-01-01

    Endocrine resistance is a major problem with anti-estrogen treatments and how to overcome resistance is a major concern in the clinic. Reliable measurement of cell viability, proliferation, growth inhibition and death is important in screening for drug treatment efficacy in vitro. This report describes and compares commonly used proliferation assays for induced estrogen-responsive MCF-7 breast cancer cell cycle arrest including: determination of cell number by direct counting of viable cells; or fluorescence SYBR®Green (SYBR) DNA labeling; determination of mitochondrial metabolic activity by 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay; assessment of newly synthesized DNA using 5-ethynyl-2'-deoxyuridine (EdU) nucleoside analog binding and Alexa Fluor® azide visualization by fluorescence microscopy; cell-cycle phase measurement by flow cytometry. Treatment of MCF-7 cells with ICI 182780 (Faslodex), FTY720, serum deprivation or induction of the tumor suppressor p14ARF showed inhibition of cell proliferation determined by the Trypan Blue exclusion assay and SYBR DNA labeling assay. In contrast, the effects of treatment with ICI 182780 or p14ARF-induction were not confirmed using the MTS assay. Cell cycle inhibition by ICI 182780 and p14ARF-induction was further confirmed by flow cytometric analysis and EdU-DNA incorporation. To explore this discrepancy further, we showed that ICI 182780 and p14ARF-induction increased MCF-7 cell mitochondrial activity by MTS assay in individual cells compared to control cells thereby providing a misleading proliferation readout. Interrogation of p14ARF-induction on MCF-7 metabolic activity using TMRE assays and high content image analysis showed that increased mitochondrial activity was concomitant with increased mitochondrial biomass with no loss of mitochondrial membrane potential, or cell death. We conclude that, whilst p14ARF and ICI 182780 stop cell cycle progression, the

  13. Molecular mechanisms underlying mangiferin-induced apoptosis and cell cycle arrest in A549 human lung carcinoma cells

    PubMed Central

    SHI, WEI; DENG, JIAGANG; TONG, RONGSHENG; YANG, YONG; HE, XIA; LV, JIANZHEN; WANG, HAILIAN; DENG, SHAOPING; QI, PING; ZHANG, DINGDING; WANG, YI

    2016-01-01

    Mangiferin, which is a C-glucosylxanthone (1,3,6,7-tetrahydroxyxanthone-C2-β-D-glucoside) purified from plant sources, has recently gained attention due to its various biological activities. The present study aimed to determine the apoptotic effects of mangiferin on A549 human lung adenocarcinoma cells. In vitro studies demonstrated that mangiferin exerted growth-inhibitory and apoptosis-inducing effects against A549 cells. In addition, mangiferin exhibited anti-tumor properties in A549 xenograft mice in vivo. Mangiferin triggered G2/M phase cell cycle arrest via down-regulating the cyclin-dependent kinase 1-cyclin B1 signaling pathway, and induced apoptotic cell death by inhibiting the protein kinase C-nuclear factor-κB pathway. In addition, mangiferin was able to enhance the antiproliferative effects of cisplatin on A549 cells, thus indicating the potential for a combined therapy. Notably, mangiferin exerted anticancer effects in vivo, where it was able to markedly decrease the volume and weight of subcutaneous tumor mass, and expand the lifespan of xenograft mice. The present study clarified the molecular mechanisms underlying mangiferin-induced antitumor activities, and suggested that mangiferin may be considered a potential antineoplastic drug for the future treatment of cancer. PMID:26935347

  14. Ailanthone Inhibits Huh7 Cancer Cell Growth via Cell Cycle Arrest and Apoptosis In Vitro and In Vivo

    PubMed Central

    Zhuo, Zhenjian; Hu, Jianyang; Yang, Xiaolin; Chen, Minfen; Lei, Xueping; Deng, Lijuan; Yao, Nan; Peng, Qunlong; Chen, Zhesheng; Ye, Wencai; Zhang, Dongmei

    2015-01-01

    While searching for natural anti-hepatocellular carcinoma (HCC) components in Ailanthus altissima, we discovered that ailanthone had potent antineoplastic activity against HCC. However, the molecular mechanisms underlying the antitumor effect of ailanthone on HCC have not been examined. In this study, the antitumor activity and the underlying mechanisms of ailanthone were evaluated in vitro and in vivo. Mechanistic studies showed that ailanthone induced G0/G1-phase cell cycle arrest, as indicated by decreased expression of cyclins and CDKs and increased expression of p21 and p27. Our results demonstrated that ailanthone triggered DNA damage characterized by activation of the ATM/ATR pathway. Moreover, ailanthone-induced cell death was associated with apoptosis, as evidenced by an increased ratio of cells in the subG1 phase and by PARP cleavage and caspase activation. Ailanthone-induced apoptosis was mitochondrion-mediated and involved the PI3K/AKT signaling pathway in Huh7 cells. In vivo studies demonstrated that ailanthone inhibited the growth and angiogenesis of tumor xenografts without significant secondary adverse effects, indicating its safety for treating HCC. In conclusion, our study is the first to report the efficacy of ailanthone against Huh7 cells and to elucidate its underlying molecular mechanisms. These findings suggest that ailanthone is a potential agent for the treatment of liver cancer. PMID:26525771

  15. DNA-damage, cell-cycle arrest and apoptosis induced in BEAS-2B cells by 2-hydroxyethyl methacrylate (HEMA).

    PubMed

    Ansteinsson, V; Solhaug, A; Samuelsen, J T; Holme, J A; Dahl, J E

    2011-08-16

    The methacrylate monomer 2-hydroxyethyl methacrylate (HEMA) is commonly used in resin-based dental restorative materials. These materials are cured in situ and HEMA and other monomers have been identified in ambient air during dental surgery. In vitro studies have demonstrated a toxic potential of methacrylates, and concerns have been raised regarding possible health effects due to inhalation. In this study we have investigated the mechanisms of HEMA-induced toxicity in the human lung epithelial cell line BEAS-2B. Depletion of cellular glutathione (GSH) and an increased level of reactive oxygen species (ROS) were seen after 2h of exposure, but the levels were restored to control levels after 12h. After 24h, inhibited cell proliferation and apoptotic cell death were found. The results of the Comet assay and the observed phosphorylation of DNA-damage-associated signalling proteins including Chk2, H2AX, and p53 suggest that the toxicity of HEMA is mediated by DNA damage. Further, the antioxidant trolox did not counteract the HEMA-induced cell-cycle arrest, which indicates that the DNA damage is of non-oxidative origin.

  16. Benfluron Induces Cell Cycle Arrest, Apoptosis and Activation of p53 Pathway in MOLT-4 Leukemic Cells.

    PubMed

    Seifrtová, M; Cochlarová, T; Havelek, R; Řezáčová, M

    2015-01-01

    The aim of our study was to determine the effect of potential anti-tumour agent benfluron on human leukemic cells MOLT-4 and elucidate the molecular mechanisms of response of tumour cells to this chemotherapeutic agent. It has been shown that the mechanisms of action of benfluron are complex, but the molecular pathways of the cytostatic effect have remained unknown and the present study contributes to their elucidation. In this work, benfluron reduced viability of the treated cells and induced caspase-mediated apoptosis. The programmed cell death was associated with activation of caspases 8, 9 and 3/7. Moreover, exposure of cells to benfluron resulted in accumulation of the cells primarily in late S and G2/M phases. The changes in the levels of key proteins show that benfluron provoked activation of p53 and induced phosphorylation of p53 on serine 15 and serine 392. The application of benfluron led to phosphorylation of Chk1 on serine 345 and phosphorylation of Chk2 on threonine 68 in the treated cells. Higher doses of benfluron caused phosphorylation of ERK1/2 on threonine 202 and tyrosine 204, whereas JNK and p38 kinases were not activated. In conclusion, benfluron induces apoptosis, cell cycle arrest in late S and G2/M phases, and activates various signalling pathways of the DNA damage response.

  17. Ayurvedic medicine constituent withaferin a causes G2 and M phase cell cycle arrest in human breast cancer cells.

    PubMed

    Stan, Silvia D; Zeng, Yan; Singh, Shivendra V

    2008-01-01

    Withaferin A (WA) is derived from the medicinal plant Withania somnifera that has been safely used for centuries in the Indian Ayurvedic medicine for treatment of various ailments. We now demonstrate that WA treatment causes G2 and mitotic arrest in human breast cancer cells. Treatment of MDA-MB-231 (estrogen-independent) and MCF-7 (estrogen-responsive) cell lines with WA resulted in a concentration- and time-dependent increase in G2-M fraction, which correlated with a decrease in levels of cyclin-dependent kinase 1 (Cdk1), cell division cycle 25C (Cdc25C) and/or Cdc25B proteins, leading to accumulation of Tyrosine15 phosphorylated (inactive) Cdk1. Ectopic expression of Cdc25C conferred partial yet significant protection against WA-mediated G2-M phase cell cycle arrest in MDA-MB-231 cells. The WA-treated MDA-MB-231 and MCF-7 cells were also arrested in mitosis as judged by fluorescence microscopy and analysis of Ser10 phosphorylated histone H3. Mitotic arrest resulting from exposure to WA was accompanied by an increase in the protein level of anaphase promoting complex/cyclosome substrate securin. In conclusion, the results of this study suggest that G2-M phase cell cycle arrest may be an important mechanism in antiproliferative effect of WA against human breast cancer cells.

  18. p53 controls CDC7 levels to reinforce G1 cell cycle arrest upon genotoxic stress

    PubMed Central

    Tudzarova, Slavica; Dey, Ayona; Stoeber, Kai; Okorokov, Andrei L.; Williams, Gareth H.

    2016-01-01

    ABSTRACT DNA replication initiation is a key event in the cell cycle, which is dependent on 2 kinases - CDK2 and CDC7. Here we report a novel mechanism in which p53 induces G1 checkpoint and cell cycle arrest by downregulating CDC7 kinase in response to genotoxic stress. We demonstrate that p53 controls CDC7 stability post-transcriptionally via miR-192/215 and post-translationally via Fbxw7β E3 ubiquitin ligase. The p53-dependent pathway of CDC7 downregulation is interlinked with the p53-p21-CDK2 pathway, as p21-mediated inhibition of CDK2-dependent phosphorylation of CDC7 on Thr376 is required for GSK3ß-phosphorylation and Fbxw7ß-dependent degradation of CDC7. Notably, sustained oncogenic high levels of active CDC7 exert a negative feedback onto p53, leading to unrestrained S-phase progression and accumulation of DNA damage. Thus, p53-dependent control of CDC7 levels is essential for blocking G1/S cell-cycle transition upon genotoxic stress, thereby safeguarding the genome from instability and thus representing a novel general stress response. PMID:27611229

  19. Effect of sesamin on apoptosis and cell cycle arrest in human breast cancer mcf-7 cells.

    PubMed

    Siao, An-Ci; Hou, Chien-Wei; Kao, Yung-Hsi; Jeng, Kee-Ching

    2015-01-01

    Dietary prevention has been known to reduce breast cancer risk. Sesamin is one of the major components in sesame seeds and has been widely studied and proven to have anti-proliferation and anti-angiogenic effects on cancer cells. In this study, the influence of sesamin was tested in the human breast cancer MCF-7 cell line for cell viability (MTT assay) and cell cycling (flow cytometry). Results showed that sesamin dose-dependently (1, 10 and 50 μM) reduced the cell viability and increased LDH release and apoptosis (TUNEL assay). In addition, there was a significant increase of sub-G1 phase arrest in the cell cycle after sesamin treatment. Furthermore, sesamin increased the expression of apoptotic markers of Bax, caspase-3, and cell cycle control proteins, p53 and checkpoint kinase 2. Taken together, these results suggested that sesamin might be used as a dietary supplement for prevention of breast cancer by modulating apoptotic signal pathways and inhibiting tumor cell growth.

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

    SciTech Connect

    Yang, Zhengmin; Cao, Yonghao; Zhu, Xiaoyan; Huang, Ying; Ding, Yuqiang; Liu, Xiaolong

    2009-08-14

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

  1. Brahma is required for cell cycle arrest and late muscle gene expression during skeletal myogenesis

    PubMed Central

    Albini, Sonia; Coutinho Toto, Paula; Dall’Agnese, Alessandra; Malecova, Barbora; Cenciarelli, Carlo; Felsani, Armando; Caruso, Maurizia; Bultman, Scott J; Puri, Pier Lorenzo

    2015-01-01

    Although the two catalytic subunits of the SWI/SNF chromatin-remodeling complex—Brahma (Brm) and Brg1—are almost invariably co-expressed, their mutually exclusive incorporation into distinct SWI/SNF complexes predicts that Brg1- and Brm-based SWI/SNF complexes execute specific functions. Here, we show that Brg1 and Brm have distinct functions at discrete stages of muscle differentiation. While Brg1 is required for the activation of muscle gene transcription at early stages of differentiation, Brm is required for Ccnd1 repression and cell cycle arrest prior to the activation of muscle genes. Ccnd1 knockdown rescues the ability to exit the cell cycle in Brm-deficient myoblasts, but does not recover terminal differentiation, revealing a previously unrecognized role of Brm in the activation of late muscle gene expression independent from the control of cell cycle. Consistently, Brm null mice displayed impaired muscle regeneration after injury, with aberrant proliferation of satellite cells and delayed formation of new myofibers. These data reveal stage-specific roles of Brm during skeletal myogenesis, via formation of repressive and activatory SWI/SNF complexes. PMID:26136374

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

    PubMed

    Gualtieri, Maurizio; Ovrevik, Johan; Mollerup, Steen; Asare, Nana; Longhin, Eleonora; Dahlman, Hans-Jørgen; Camatini, Marina; Holme, Jørn A

    2011-08-01

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

  3. 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.

  4. 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.

  5. 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

  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. p21WAF1 modulates drug-induced apoptosis and cell cycle arrest in B-cell precursor acute lymphoblastic leukemia

    PubMed Central

    Davies, Carwyn; Hogarth, Linda A; Mackenzie, Karen L; Hall, Andrew G; Lock, Richard B

    2015-01-01

    p21WAF1 is a well-characterized mediator of cell cycle arrest and may also modulate chemotherapy-induced cell death. The role of p21WAF1 in drug-induced cell cycle arrest and apoptosis of acute lymphoblastic leukemia (ALL) cells was investigated using p53-functional patient-derived xenografts (PDXs), in which p21WAF1 was epigenetically silenced in T-cell ALL (T-ALL), but not in B-cell precursor (BCP)-ALL PDXs. Upon exposure to diverse cytotoxic drugs, T-ALL PDX cells exhibited markedly increased caspase-3/7 activity and phosphatidylserine (PS) externalization on the plasma membrane compared with BCP-ALL cells. Despite dramatic differences in apoptotic characteristics between T-ALL and BCP-ALL PDXs, both ALL subtypes exhibited similar cell death kinetics and were equally sensitive to p53-inducing drugs in vitro, although T-ALL PDXs were significantly more sensitive to the histone deacetylase inhibitor vorinostat. Transient siRNA suppression of p21WAF1 in the BCP-ALL 697 cell line resulted in a moderate depletion of the cell fraction in G1 phase and marked increase in PS externalization following exposure to etoposide. Furthermore, stable lentiviral p21WAF1 silencing in the BCP-ALL Nalm-6 cell line accelerated PS externalization and cell death following exposure to etoposide and vorinostat, supporting previous findings. Finally, the Sp1 inhibitor, terameprocol, inhibited p21WAF1 expression in Nalm-6 cells exposed to vorinostat and also partially augmented vorinostat-induced cell death. Taken together, these findings demonstrate that p21WAF1 regulates the early stages of drug-induced apoptosis in ALL cells and significantly modulates their sensitivity to vorinostat. PMID:26506264

  8. Combination of PTEN and {gamma}-Ionizing Radiation Enhances Cell Death and G{sub 2}/M Arrest Through Regulation of AKT Activity and p21 Induction in Non-Small-Cell Lung Cancer Cells

    SciTech Connect

    Park, Jong Kuk; Jung, Hae-Yun; Park, Seon Ho; Kang, Seung Yi; Yi, Mi-Rang; Um, Hong Duck; Hong, Sung Hee

    2008-04-01

    Purpose: To identify the role of phosphatase and tensin homolog deleted on chromosome 10 (PTEN) during {gamma}-ionizing radiation ({gamma}-IR) treatment for non-small-cell lung cancer cells. Methods and Materials: Wild-type PTEN or mutant forms of PTEN plasmids were transfected to construct stable transfectants of the NCI-H1299 non-small-cell lung cancer cell line. Combined effects of PTEN expression and IR treatment were tested using immunoblot, clonogenic, and cell-counting assays. Related signaling pathways were studied with immunoblot and kinase assays. Results: At steady state, stable transfectants showed almost the same proliferation rate but had different AKT phosphorylation patterns. When treated with {gamma}-IR, wild-type PTEN transfectants showed higher levels of cell death compared with mock vector or mutant transfectants, and showed increased G{sub 2}/M cell-cycle arrest accompanied by p21 induction and CDK1 inactivation. NCI-H1299 cells were treated with phosphosinositide-3 kinase (PI3K)/AKT pathway inhibitor (LY29002), resulting in reduced AKT phosphorylation levels. Treatment of NCI-H1299 cells with LY29002 and {gamma}-IR resulted in increased cell-cycle arrest and p21 induction. Endogenous wild-type PTEN-containing NCI-H460 cells were treated with PTEN-specific siRNA and then irradiated with {gamma}-IR: however reduced PTEN levels did not induce cell-cycle arrest or p21 expression. Conclusions: Taken together, these findings indicate that PTEN may modulate cell death or the cell cycle via AKT inactivation by PTEN and {gamma}-IR treatment. We also propose that a PTEN-PI3K/AKT-p21-CDK1 pathway could regulate cell death and the cell cycle by {gamma}-IR treatment.

  9. Suppression of the allogeneic response by the anti-allergy drug N-(3,4-dimethoxycinnamonyl) anthranilic acid results from T-cell cycle arrest.

    PubMed

    Zaher, Sarah S; Coe, David; Chai, Jian-Guo; Larkin, Daniel F P; George, Andrew J T

    2013-02-01

    Previously we have shown that indoleamine 2,3-dioxygenase (IDO) and the tryptophan metabolite, 3-hydroxykynurenine (3HK) can prolong corneal allograft survival. IDO modulates the immune response by depletion of the essential amino acid tryptophan by breakdown to kynurenines, which themselves act directly on T lymphocytes. The tryptophan metabolite analogue N-(3,4-dimethoxycinnamonyl) anthranilic acid (DAA, 'Tranilast') shares the anthranilic acid core with 3HK. Systemic administration of DAA to mice receiving a fully MHC-mismatched allograft of cornea or skin resulted in significant delay in rejection (median survival of controls 12 days, 13 days for cornea and skin grafts, respectively, and of treated mice 24 days (P < 0.0001) and 17 days (P < 0.03), respectively). We provide evidence that DAA-induced suppression of the allogeneic response, in contrast to that induced by tryptophan metabolites, was a result of cell cycle arrest rather than T-cell death. Cell cycle arrest was mediated by up-regulation of the cell cycle-specific inhibitors p21 and p15, and associated with a significant reduction in interleukin-2 production, allowing us to characterize a novel mechanism for DAA-induced T-cell anergy. Currently licensed as an anti-allergy drug, the oral bioavailability and safe therapeutic profile of DAA make it a candidate for the prevention of rejection of transplanted cornea and other tissues.

  10. The neem limonoids azadirachtin and nimbolide induce cell cycle arrest and mitochondria-mediated apoptosis in human cervical cancer (HeLa) cells.

    PubMed

    Priyadarsini, R Vidya; Murugan, R Senthil; Sripriya, P; Karunagaran, D; Nagini, S

    2010-06-01

    Limonoids from the neem tree (Azadirachta indica) have attracted considerable research attention in recent years owing to their potent antioxidant and anti-proliferative effects. The present study was designed to investigate the cellular and molecular mechanisms by which azadirachtin and nimbolide exert cytotoxic effects in the human cervical cancer (HeLa) cell line. Both azadirachtin and nimbolide significantly suppressed the viability of HeLa cells in a dose-dependent manner by inducing cell cycle arrest at G0/G1 phase accompanied by p53-dependent p21 accumulation and down-regulation of the cell cycle regulatory proteins cyclin B, cyclin D1 and PCNA. Characteristic changes in nuclear morphology, presence of a subdiploid peak and annexin-V staining pointed to apoptosis as the mode of cell death. Increased generation of reactive oxygen species with decline in the mitochondrial transmembrane potential and release of cytochrome c confirmed that the neem limonoids transduced the apoptotic signal via the mitochondrial pathway. Altered expression of the Bcl-2 family of proteins, inhibition of NF-kappaB activation and over-expression of caspases and survivin provide compelling evidence that azadirachtin and nimbolide induce a shift of balance toward a pro-apoptotic phenotype. Antioxidants such as azadirachtin and nimbolide that can simultaneously arrest the cell cycle and target multiple molecules involved in mitochondrial apoptosis offer immense potential as anti-cancer therapeutic drugs.

  11. Mechanism of T-oligo-induced cell cycle arrest in Mia-PaCa pancreatic cancer cells.

    PubMed

    Rankin, Andrew M; Sarkar, Sibaji; Faller, Douglas V

    2012-06-01

    DNA oligonucleotides with sequence homology to human telomeric DNA (T-oligo) induce cell cycle arrest, followed by apoptosis, senescence, or autophagy in a human cancer cell type-specific manner. T-oligo has potential as a new therapeutic strategy in oncology because of its ability to target certain types of tumor cells while sparing normal ones. In the present study, we demonstrate the T-oligo-induced S-phase cell cycle arrest in four pancreatic cancer cell lines. To further contribute to the mechanistic understanding of T-oligo, we also identify cyclin dependent kinase 2 (cdk2) as a functional mediator in the T-oligo-induced cell cycle arrest of pancreatic cancer cells. Ectopic expression of a constitutively active cdk2 mutant abrogates T-oligo-induced cell cycle arrest in these tumor cells while knockdown of cdk2 expression alone recapitulates the T-oligo effect. Finally, we demonstrate the dispensability of T-oligo-induced ATM/ATR-mediated DNA damage response-signaling pathways, which have long been considered functional in the T-oligo signaling mechanism.

  12. 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.

  13. Glucose capped silver nanoparticles induce cell cycle arrest in HeLa cells.

    PubMed

    Panzarini, Elisa; Mariano, Stefania; Vergallo, Cristian; Carata, Elisabetta; Fimia, Gian Maria; Mura, Francesco; Rossi, Marco; Vergaro, Viviana; Ciccarella, Giuseppe; Corazzari, Marco; Dini, Luciana

    2017-02-20

    This study aims to determine the interaction (uptake and biological effects on cell viability and cell cycle progression) of glucose capped silver nanoparticles (AgNPs-G) on human epithelioid cervix carcinoma (HeLa) cells, in relation to amount, 2×10(3) or 2×10(4) NPs/cell, and exposure time, up to 48h. The spherical and well dispersed AgNPs (30±5nm) were obtained by using glucose as reducing agent in a green synthesis method that ensures to stabilize AgNPs avoiding cytotoxic soluble silver ions Ag(+) release. HeLa cells take up abundantly and rapidly AgNPs-G resulting toxic to cells in amount and incubation time dependent manner. HeLa cells were arrested at S and G2/M phases of the cell cycle and subG1 population increased when incubated with 2×10(4) AgNPs-G/cell. Mitotic index decreased accordingly. The dissolution experiments demonstrated that the observed effects were due only to AgNPs-G since glucose capping prevents Ag(+) release. The AgNPs-G influence on HeLa cells viability and cell cycle progression suggest that AgNPs-G, alone or in combination with chemotherapeutics, may be exploited for the development of novel antiproliferative treatment in cancer therapy. However, the possible influence of the cell cycle on cellular uptake of AgNPs-G and the mechanism of AgNPs entry in cells need further investigation.

  14. The molecular mechanism of G2/M cell cycle arrest induced by AFB1 in the jejunum

    PubMed Central

    Yin, Heng; Jiang, Min; Peng, Xi; Cui, Hengmin; Zhou, Yi; He, Min; Zuo, Zhicai; Ouyang, Ping; Fan, Junde; Fang, Jing

    2016-01-01

    Aflatoxin B1 (AFB1) has potent hepatotoxic, carcinogenic, genotoxic, immunotoxic and other adverse effects in human and animals. The aim of this study was to investigate the molecular mechanism of G2/M cell cycle arrest induced by AFB1 in the jejunum of broilers. Broilers, as experimental animals, were fed 0.6 mg/kg AFB1 diet for 3 weeks. Our results showed that AFB1 reduced the jejunal villus height, villus height/crypt ratio and caused G2/M cell cycle arrest. The G2/M cell cycle was accompanied by the increase of ataxia telangiectasia mutated (ATM), p53, Chk2, p21 protein and mRNA expression, and the decrease of Mdm2, cdc25C, cdc2, cyclin B and proliferating cell nuclear antigen protein and mRNA expression. In conclusion, AFB1 blocked G2/M cell cycle by ATM pathway in the jejunum of broilers. PMID:27232757

  15. Invasive Cell Fate Requires G1 Cell-Cycle Arrest and Histone Deacetylase-Mediated Changes in Gene Expression.

    PubMed

    Matus, David Q; Lohmer, Lauren L; Kelley, Laura C; Schindler, Adam J; Kohrman, Abraham Q; Barkoulas, Michalis; Zhang, Wan; Chi, Qiuyi; Sherwood, David R

    2015-10-26

    Despite critical roles in development and cancer, the mechanisms that specify invasive cellular behavior are poorly understood. Through a screen of transcription factors in Caenorhabditis elegans, we identified G1 cell-cycle arrest as a precisely regulated requirement of the anchor cell (AC) invasion program. We show that the nuclear receptor nhr-67/tlx directs the AC into G1 arrest in part through regulation of the cyclin-dependent kinase inhibitor cki-1. Loss of nhr-67 resulted in non-invasive, mitotic ACs that failed to express matrix metalloproteinases or actin regulators and lack invadopodia, F-actin-rich membrane protrusions that facilitate invasion. We further show that G1 arrest is necessary for the histone deacetylase HDA-1, a key regulator of differentiation, to promote pro-invasive gene expression and invadopodia formation. Together, these results suggest that invasive cell fate requires G1 arrest and that strategies targeting both G1-arrested and actively cycling cells may be needed to halt metastatic cancer.

  16. Ellagic acid suppresses lipid accumulation by suppressing early adipogenic events and cell cycle arrest.

    PubMed

    Woo, Mi-Seon; Choi, Hyeon-Son; Seo, Min-Jung; Jeon, Hui-Jeon; Lee, Boo-Yong

    2015-03-01

    Ellagic acid (EA) is a natural polyphenol found in various fruits and vegetables. In this study, we examined the inhibitory effect of EA on fat accumulation in 3T3-L1 cells during adipogenesis. Our data showed that EA reduced fat accumulation by down-regulating adipogenic markers such as peroxisome proliferator activated receptor γ (PPARγ) and the CCAAT/enhancer binding protein α (C/EBPα) at the mRNA and protein levels in a dose-dependent manner. We found that the decrease in adipogenic markers resulted from reduced expression of some early adipogenic transcription factors such as KLF4, KLF5, Krox20, and C/EBPβ within 24 h. Also, these inhibitions were correlated with down-regulation of TG synthetic enzymes, causing inhibition of triglyceride (TG) levels in 3T3-L1 cells investigated by ORO staining and in zebrafish investigated by TG assay. Additionally, the cell cycle analysis showed that EA inhibited cell cycle progression by arresting cells at the G0/G1 phase.

  17. Paris Saponin I Sensitizes Gastric Cancer Cell Lines to Cisplatin via Cell Cycle Arrest and Apoptosis

    PubMed Central

    Song, Shuichuan; Du, Leiwen; Jiang, Hao; Zhu, Xinhai; Li, Jinhui; Xu, Ji

    2016-01-01

    Background Dose-related toxicity is the major restriction of cisplatin and cisplatin-combination chemotherapy, and is a challenge for advanced gastric cancer treatment. We explored the possibility of using Paris saponin I as an agent to sensitize gastric cancer cells to cisplatin, and examined the underlying mechanism. Material/Methods Growth inhibition was detected by MTT assay. The cell cycle and apoptosis were detected using flow cytometry and Annexin V/PI staining. The P21waf1/cip1, Bcl-2, Bax, and caspase-3 protein expression were detected using Western blot analysis. Results The results revealed that PSI sensitized gastric cancer cells to cisplatin, with low toxicity. The IC50 value of cisplatin in SGC-7901 cell lines was decreased when combined with PSI. PSI promoted cisplatin-induced G2/M phase arrest and apoptosis in a cisplatin concentration-dependent manner. Bcl-2 protein expression decreased, but Bax, caspase-3, and P21waf1/cip1 protein expression increased with PSI treatment. Conclusions The underlying mechanism of Paris saponin I may be related to targeting the apoptosis pathway and cell cycle blocking, which suggests that PSI is a potential therapeutic sensitizer for cisplatin in treating gastric cancer. PMID:27755523

  18. Human rabies deaths in Africa: breaking the cycle of indifference.

    PubMed

    Dodet, Betty; Tejiokem, Mathurin C; Aguemon, Abdou-Rahman; Bourhy, Hervé

    2015-01-01

    The current outbreak of Ebola virus disease has mobilized the international community against this deadly disease. However, rabies, another deadly disease, is greatly affecting the African continent, with an estimated 25 000 deaths every year. And yet, the disease can be prevented by a vaccine, if necessary with immunoglobulin, even when administered after exposure to the rabies virus. Rabies victims die because of neglect and ignorance, because they are not aware of these life-saving biologicals, or because they cannot access them or do not have the money to pay for them. Breaking the cycle of indifference of rabies deaths in humans in Africa should be a priority of governments, international organizations and all stakeholders involved.

  19. Sorbus rufopilosa Extract Exhibits Antioxidant and Anticancer Activities by Inducing Cell Cycle Arrest and Apoptosis in Human Colon Adenocarcinoma HT29 Cells

    PubMed Central

    Oh, You Na; Jin, Soojung; Park, Hyun-Jin; Kwon, Hyun Ju; Kim, Byung Woo

    2016-01-01

    Background Sorbus rufopilosa, a tsema rowan, is a species of the small ornamental trees in the genus Sorbus and the family Rosaceae found in East Asia. The bioactivities of S. rufopilosa have not yet been fully determined. The objective of this study is to evaluate the antioxidant and anticancer effects of ethanol extract of S. rufopilosa (EESR) and to determine the molecular mechanism of its anticancer activity in human colon carcinoma HT29 cells. Methods To examine the antioxidant activity of EESR, 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity assay was performed. Inhibitory effect of EESR on cancer cell growth and proliferation was determined by water-soluble tetrazolium salt assay. To investigate the mechanism of EESR-mediated cytotoxicity, HT29 cells were treated with various concentrations of EESR and the induction of cell cycle arrest and apoptosis was analyzed by flow cytometry, 4,6-diamidino-2-phenylindole staining, and Western blot analysis. Results EESR showed significant antioxidant activity and inhibitory effect on HT29 cell growth in a dose-dependent manner. EESR induced cell cycle arrest at G2/M phase in a dose-dependent manner by modulating cyclin B, cyclin-dependent kinase 1 (CDK1), and CDK inhibitor p21 expression. EESR-induced apoptosis was associated with the upregulation of p53, a death receptor Fas, and a pro-apoptotic protein Bax and the activation of caspase 3, 8, and 9, resulting in the degradation of PARP. Conclusions EESR possessing antioxidant activity efficiently inhibits proliferation of HT29 cells by inducing both cell cycle arrest and apoptosis. EESR may be a possible candidate for the anticancer drug development. PMID:28053959

  20. Critical Role of AMPK/FoxO3A Axis in Globular Adiponectin-Induced Cell Cycle Arrest and Apoptosis in Cancer Cells.

    PubMed

    Shrestha, Anup; Nepal, Saroj; Kim, Mi Jin; Chang, Jae Hoon; Kim, Sang-Hyun; Jeong, Gil-Saeng; Jeong, Chul-Ho; Park, Gyu Hwan; Jung, Sunghee; Lim, Jaecheong; Cho, Eunha; Lee, Soyoung; Park, Pil-Hoon

    2016-02-01

    Adiponectin predominantly secreted from adipose tissue has exhibited potent anti-proliferative properties in cancer cells via modulating cell cycle and apoptosis. FoxO3A, a Forkhead box O member of the transcription factor, plays a critical role in modulating expression of genes involved in cell death and/or survival. In this study, we investigated the role of FoxO3A signaling in anti-cancer activities of adiponectin. Herein, we have shown that treatment with globular adiponectin (gAcrp) increases p27 but decreases cyclinD1 expression in human hepatoma (HepG2) and breast (MCF-7) cancer cells. Gene ablation of FoxO3A prevented gAcrp-induced increase in p27 and decreased in cyclin D1 expression, and further ameliorated cell cycle arrest by gAcrp, indicating a critical role of FoxO3A in gAcrp-induced cell cycle arrest of cancer cells. Moreover, treatment with gAcrp also induced caspase-3/7 activation and increased Fas ligand (FasL) expression in both HepG2 and MCF-7 cells. Transfection with FoxO3A siRNA inhibited gAcrp-induced caspase-3/7 activation and FasL expression, suggesting that FoxO3A signaling also plays an important role in gAcrp-induced apoptosis of cancer cells. We also found that gene silencing of AMPK prevented gAcrp-induced nuclear translocation of FoxO3A in HepG2 and MCF-7 cells. In addition, suppression of AMPK also blocked gAcrp-induced cell cycle arrest and further attenuated gAcrp-induced caspase-3/7 activation, indicating that AMPK signaling plays a pivotal role in both gAcrp-induced cell cycle arrest and apoptosis via acting as an upstream signaling of FoxO3A. Taken together, our findings demonstrated that AMPK/FoxO3A axis plays a cardinal role in anti-proliferative effect of adiponectin in cancer cells.

  1. Clove Extract Inhibits Tumor Growth and Promotes Cell Cycle Arrest and Apoptosis

    PubMed Central

    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 p21WAF1/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. PMID:24854101

  2. 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.

  3. 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.

  4. PD98059 Protects Brain against Cells Death Resulting from ROS/ERK Activation in a Cardiac Arrest Rat Model.

    PubMed

    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.

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

    PubMed

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

    2013-09-01

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

  6. Physalin A induces G2/M phase cell cycle arrest in human non-small cell lung cancer cells: involvement of the p38 MAPK/ROS pathway.

    PubMed

    Kang, Ning; Jian, Jun-Feng; Cao, Shi-Jie; Zhang, Qiang; Mao, Yi-Wei; Huang, Yi-Yuan; Peng, Yan-Fei; Qiu, Feng; Gao, Xiu-Mei

    2016-04-01

    Physalin A (PA) is an active withanolide isolated from Physalis alkekengi var. franchetii, a traditional Chinese herbal medicine named Jindenglong, which has long been used for the treatment of sore throat, hepatitis, and tumors in China. In the present study, we firstly investigated the effects of PA on proliferation and cell cycle distribution of the human non-small cell lung cancer (NSCLC) A549 cell line, and the potential mechanisms involved. Here, PA inhibited cell growth in dose- and time-dependent manners. Treatment of A549 cells with 28.4 μM PA for 24 h resulted in approximately 50 % cell death. PA increased the amount of intracellular ROS and the proportion of cells in G2/M. G2/M arrest was attenuated by the addition of ROS scavenger NAC. ERK and P38 were triggered by PA through phosphorylation in a time-dependent manner. The phosphorylation of ERK and P38 were not attenuated by the addition of NAC, but the use of the p38 inhibitor could reduce, at least in part, PA-induced ROS and the proportion of cells in G2/M. PA induces G2/M cell cycle arrest in A549 cells involving in the p38 MAPK/ROS pathway. This study suggests that PA might be a promising therapeutic agent against NSCLC.

  7. 53BP1 and USP28 mediate p53-dependent cell cycle arrest in response to centrosome loss and prolonged mitosis

    PubMed Central

    Fong, Chii Shyang; Mazo, Gregory; Das, Tuhin; Goodman, Joshua; Kim, Minhee; O'Rourke, Brian P; Izquierdo, Denisse; Tsou, Meng-Fu Bryan

    2016-01-01

    Mitosis occurs efficiently, but when it is disturbed or delayed, p53-dependent cell death or senescence is often triggered after mitotic exit. To characterize this process, we conducted CRISPR-mediated loss-of-function screens using a cell-based assay in which mitosis is consistently disturbed by centrosome loss. We identified 53BP1 and USP28 as essential components acting upstream of p53, evoking p21-dependent cell cycle arrest in response not only to centrosome loss, but also to other distinct defects causing prolonged mitosis. Intriguingly, 53BP1 mediates p53 activation independently of its DNA repair activity, but requiring its interacting protein USP28 that can directly deubiquitinate p53 in vitro and ectopically stabilize p53 in vivo. Moreover, 53BP1 can transduce prolonged mitosis to cell cycle arrest independently of the spindle assembly checkpoint (SAC), suggesting that while SAC protects mitotic accuracy by slowing down mitosis, 53BP1 and USP28 function in parallel to select against disturbed or delayed mitosis, promoting mitotic efficiency. DOI: http://dx.doi.org/10.7554/eLife.16270.001 PMID:27371829

  8. 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

  9. 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

  10. Knockdown of USP39 induces cell cycle arrest and apoptosis in melanoma.

    PubMed

    Zhao, Yuan; Zhang, Bo; Lei, Yu; Sun, Jingying; Zhang, Yaohua; Yang, Sen; Zhang, Xuejun

    2016-10-01

    The spliceosome machinery composed of multimeric protein complexes guides precursor messenger RNAs (mRNAs) (pre-mRNAs) splicing in eukaryotic cells. Spliceosome components have been shown to be downregulated in cancer and could be a promising molecular target for anticancer therapy. The ubiquitin-specific protease 39 (USP39) is essential for pre-mRNA splicing, and upregulated USP39 expression is noted in a variety of cancers. However, the role of USP39 in the development and progression of melanoma remains unclear. In the present study, USP39 expression was found to be increased in melanoma tissues compared with that in nevus tissues. USP39 silencing via lentivirus-mediated short hairpin RNA (shRNA) significantly suppressed melanoma cell proliferation, induced G0/G1 cell cycle phase arrest, and increased apoptosis in vitro. Moreover, USP39 knockdown suppressed melanoma tumor growth in a xenograft model. In addition, USP39 silencing was associated with the increased expressions of p21, p27, and Bax. Furthermore, the inhibition of USP39 expression decreased the phosphorylation of extracellular signal-regulated kinase (ERK)1/2, indicating that ERK signaling pathways might be involved in the regulation of melanoma cell proliferation by USP39. Our findings suggest that USP39 may play crucial roles in the development and pathogenesis of melanoma, and it may serve as a potential therapeutic target for melanoma.

  11. Telomere loss in somatic cells of Drosophila causes cell cycle arrest and apoptosis.

    PubMed Central

    Ahmad, K; Golic, K G

    1999-01-01

    Checkpoint mechanisms that respond to DNA damage in the mitotic cell cycle are necessary to maintain the fidelity of chromosome transmission. These mechanisms must be able to distinguish the normal telomeres of linear chromosomes from double-strand break damage. However, on several occasions, Drosophila chromosomes that lack their normal telomeric DNA have been recovered, raising the issue of whether Drosophila is able to distinguish telomeric termini from nontelomeric breaks. We used site-specific recombination on a dispensable chromosome to induce the formation of a dicentric chromosome and an acentric, telomere-bearing, chromosome fragment in somatic cells of Drosophila melanogaster. The acentric fragment is lost when cells divide and the dicentric breaks, transmitting a chromosome that has lost a telomere to each daughter cell. In the eye imaginal disc, cells with a newly broken chromosome initially experience mitotic arrest and then undergo apoptosis when cells are induced to divide as the eye differentiates. Therefore, Drosophila cells can detect and respond to a single broken chromosome. It follows that transmissible chromosomes lacking normal telomeric DNA nonetheless must possess functional telomeres. We conclude that Drosophila telomeres can be established and maintained by a mechanism that does not rely on the terminal DNA sequence. PMID:10049921

  12. Bracken-fern extracts induce cell cycle arrest and apoptosis in certain cancer cell lines.

    PubMed

    Roudsari, Motahhareh Tourchi; Bahrami, Ahmad Reza; Dehghani, Hesam

    2012-01-01

    Bracken fern [Pteridium aquilinem (L.) kuhn (Dennstaedtiaceae)] is one of the most common species on the planet. It has been consumed by humans and animals for centuries. Use by some human groups is because they believe bracken fern is good for health as plant medicine. However, it is also one of the few known plants that can cause tumors in farm animals. Many interested groups have focused their attention on bracken fern because of these interesting features. In order to evaluate the biological effects of exposure to this plant in cellular level, human cancer cell lines were treated with the fern dichloromethane extracts and the genotoxic and cytotoxic effects were studied. Anti-proliferative/cytotoxic effects were evaluated by cell count, MTT assay and flow cytometry methods with three different cancer cell lines, TCC, NTERA2, and MCF-7, and two normal cells, HDF1 and HFF3. Pro-apoptotic effects of the extracts were determined by DAPI staining and comet assay, on TCC cancer cells compared to the normal control cell lines. Cellular morphology was examined by light microscopy. Our present study showed that the extract caused DNA damage and apoptosis at high concentrations (200 μg/mL) and also it may induce cell cycle arrest (G2/M phase) at mild concentrations (50 and 30 μg/mL) depending on the cell type and tumor origin. These results indicate that bracken fern extract is a potent source of anticancer compounds that could be utilized pharmaceutically.

  13. Imaging Bone Morphogenetic Protein 7 Induced Cell Cycle Arrest in Experimental Gliomas12

    PubMed Central

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

    2011-01-01

    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 G1 phase but not by induction of apoptosis. This effect was mediated by the modulation of the expression and phosphorylation of cyclin-dependent kinase 2, cyclin-dependent kinase inhibitor p21, and downstream retinoblastoma protein. Furthermore, in vivo optical imaging of luciferase activity of Gli36ΔEGFR-LITG cells implanted intracranially into nude mice in the presence or absence of BMP-7 treatment corroborated the antiproliferative effects of this cytokine. This report clearly underlines the tumor-suppressive role of BMP-7 in glioma-derived cells. Taken together, our results indicate that manipulating the BMP/transforming growth factor β signaling cascade may serve as a new strategy for imaging-guided molecular-targeted therapy of malignant gliomas. PMID:21390190

  14. Pterostilbene induces apoptosis and cell cycle arrest in diffuse large B-cell lymphoma cells

    PubMed Central

    Kong, Yuanyuan; Chen, Gege; Xu, Zhijian; Yang, Guang; Li, Bo; Wu, Xiaosong; Xiao, Wenqin; Xie, Bingqian; Hu, Liangning; Sun, Xi; Chang, Gaomei; Gao, Minjie; Gao, Lu; Dai, Bojie; Tao, Yi; Zhu, Weiliang; Shi, Jumei

    2016-01-01

    Diffuse large B-cell lymphoma (DLBCL) is the most common type of non-Hodgkin lymphoma (NHL). Pterostilbene, a natural dimethylated analog of resveratrol, has been shown to possess diverse pharmacological activities, including anti-inflammatory, antioxidant and anticancer properties. However, to the best of our knowledge, there has been no study of the effects of pterostilbene upon hematological malignancies. Herein, we report the antitumor activity and mechanism of pterostilbene against DLBCL cells both in vitro and in vivo. We found that pterostilbene treatment resulted in a dose-dependent inhibition of cell viability. In addition, pterostilbene exhibited a strong cytotoxic effect, as evidenced not only by reductions of mitochondrial membrane potential (MMP) but also by increases in cellular apoptotic index and reactive oxygen species (ROS) levels, leading to arrest in the S-phase of the cell cycle. Furthermore, pterostilbene treatment directly up-regulated p-p38MAPK and down-regulated p-ERK1/2. In vivo, intravenous administration of pterostilbene inhibited tumor development in xenograft mouse models. Overall, the results suggested that pterostilbene is a potential anti-cancer pharmaceutical against human DLBCL by a mechanism involving the suppression of ERK1/2 and activation of p38MAPK signaling pathways. PMID:27869173

  15. 2'-Nitroflavone induces cell cycle arrest and apoptosis in HeLa human cervical carcinoma cells.

    PubMed

    Cárdenas, Mariano G; Blank, Viviana C; Marder, Mariel; Roguin, Leonor P

    2008-09-08

    The mechanism of antitumor action of a synthetic nitroflavone derivative, 2'-nitroflavone, was evaluated in vitro in HeLa human cervix adenocarcinoma cells. We showed that the nitroflavone derivative slowed down the cell cycle at the S phase and increase the population of cells at the G2/M phase after 24h of incubation. The treatment with 2'-nitroflavone also induced an apoptotic response, characterized by an increase of the sub-G1 fraction of cells, by cells with chromatin condensation and membrane blebbing, by a typical ladder of DNA fragmentation and by detection of apoptotic cells stained with Annexin V. The observed apoptosis was regulated by caspase-8 and -9, both contributing to the activation of the effector caspase-3. In addition, inhibitors of caspase-8 or -9 partially protected HeLa cells from 2'-nitroflavone-induced cell death. We also found that 2'-nitroflavone did not affect the total amount of Bax and Bcl-2 proteins, although a translocation of Bax from cytosol to mitochondria was evident after 6h of exposure. Furthermore, 2'-nitroflavone decreased the expression of the anti-apoptotic Bcl-XL protein, induced the release of cytochrome C to cytosol and increased the levels of Fas and Fas-L. Our results indicated that both death receptor and mitochondria-dependent pathways are involved in the apoptotic cell death triggered by 2'-nitroflavone and suggest that this derivative could be a potentially useful agent for the treatment of certain malignancies.

  16. Silymarin induces cell cycle arrest and apoptosis in ovarian cancer cells.

    PubMed

    Fan, Li; Ma, Yalin; Liu, Ying; Zheng, Dongping; Huang, Guangrong

    2014-11-15

    The polyphenolic flavonoid silymarin that is the milk thistle extract has been found to possess an anti-cancer effect against various human epithelial cancers. In this study, to explore the regulative effect of silymarin on human ovarian cancer line A2780s and PA-1 cells, 3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyltetrazolium bromide assay and flow cytometry were respectively used to determine the inhibitory effect of silymarin on the both cell lines, and to measure their cell cycle progression. Apoptosis induction and mitochondrial membrane potential damage were separately detected by terminal deoxynucleotidyl transferase-mediated 2'-deoxyuridine 5'-triphosphate nick end labeling assay and 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimidazolylcarbocyanine iodide staining. Additionally, western blotting was applied to determine cytochrome C release and expression levels of p53, p21, p27, p16, CDK2, Bax, Bcl-2, procaspase-9, procaspase-3, cleaved caspase-9 and caspase-3 proteins. The activity of caspase-9 and caspase-3 was measured using Caspase-Glo-9 and Caspase-Glo-3 assay. The results indicated that silymarin effectively suppressed cell growth in a dose- and time-dependent manner, and arrested cell cycle progression at G1/S phase in A2780s and PA-1 cells via up-regulation of p53, p21, and p27 protein expression, and down-regulation of CDK2 protein expression. Additionally, silymarin treatment for 24h at 50 and 100µg/ml resulted in a reduction of mitochondrial membrane potential and cytochrome C release, and significantly induced apoptosis in A2780s and PA-1 cells by increasing Bax and decreasing Bcl-2 protein expression, and activation of caspase-9 and caspase-3. Therefore, silymarin is a possible potential candidate for the prevention and treatment of ovarian cancer.

  17. 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.

  18. 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.

  19. 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.

  20. Human cytochrome c enters murine J774 cells and causes G{sub 1} and G{sub 2}/M cell cycle arrest and induction of apoptosis

    SciTech Connect

    Hiraoka, Yoshinori; Granja, Ana Teresa; Fialho, Arsenio M.; Schlarb-Ridley, Beatrix G.; Das Gupta, Tapas K.; Chakrabarty, Ananda M.; Yamada, Tohru . E-mail: tohru@uic.edu

    2005-12-16

    Cytochrome c is well known as a carrier of electrons during respiration. Current evidence indicates that cytochrome c also functions as a major component of apoptosomes to induce apoptosis in eukaryotic cells as well as an antioxidant. More recently, a prokaryotic cytochrome c, cytochrome c {sub 551} from Pseudomonas aeruginosa, has been shown to enter in mammalian cells such as the murine macrophage-like J774 cells and causes inhibition of cell cycle progression. Much less is known about such functions by mammalian cytochromes c, particularly the human cytochrome c. We now report that similar to P. aeruginosa cytochrome c {sub 551}, the purified human cytochrome c protein can enter J774 cells and induce cell cycle arrest at the G{sub 1} to S phase, as well as at the G{sub 2}/M phase at higher concentrations. Unlike P. aeruginosa cytochrome c {sub 551} which had no effect on the induction of apoptosis, human cytochrome c induces significant apoptosis and cell death in J774 cells, presumably through inhibition of the cell cycle at the G{sub 2}/M phase. When incubated with human breast cancer MCF-7 and normal mammary epithelial cell line MCF-10A1 cells, human cytochrome c entered in both types of cells but induced cell death only in the normal MCF-10A1 cells. The ability of human cytochrome c to enter J774 cells was greatly reduced at 4 deg. C, suggesting energy requirement in the entry process.

  1. 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

  2. Oxidative stress, apoptosis, and cell cycle arrest are induced in primary fetal alveolar type II epithelial cells exposed to fine particulate matter from cooking oil fumes.

    PubMed

    Liu, Ying; Chen, Yan-Yan; Cao, Ji-Yu; Tao, Fang-Biao; Zhu, Xiao-Xia; Yao, Ci-Jiang; Chen, Dao-Jun; Che, Zhen; Zhao, Qi-Hong; Wen, Long-Ping

    2015-07-01

    Epidemiological studies demonstrate a linkage between morbidity and mortality and particulate matter (PM), particularly fine particulate matter (PM2.5) that can readily penetrate into the lungs and are therefore more likely to increase the incidence of respiratory and cardiovascular diseases. The present study investigated the compositions of cooking oil fume (COF)-derived PM2.5, which is the major source of indoor pollution in China. Furthermore, oxidative stress, cytotoxicity, apoptosis, and cell cycle arrest induced by COF-derived PM2.5 in primary fetal alveolar type II epithelial cells (AEC II cells) were also detected. N-acetyl-L-cysteine (NAC), a radical scavenger, was used to identify the role of oxidative stress in the abovementioned processes. Our results suggested that compositions of COF-derived PM2.5 are obviously different to PM2.5 derived from other sources, and COF-derived PM2.5 led to cell death, oxidative stress, apoptosis, and G0/G1 cell arrest in primary fetal AEC II cells. Furthermore, the results also showed that COF-derived PM2.5 induced apoptosis through the endoplasmic reticulum (ER) stress pathway, which is indicated by the increased expression of ER stress-related apoptotic markers, namely GRP78 and caspase-12. Besides, the induction of oxidative stress, cytotoxicity, apoptosis, and cell cycle arrest was reversed by pretreatment with NAC. These findings strongly suggested that COF-derived PM2.5-induced toxicity in primary fetal AEC II cells is mediated by increased oxidative stress, accompanied by ER stress which results in apoptosis.

  3. 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.

  4. 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.

  5. SKLB70326, a novel small-molecule inhibitor of cell-cycle progression, induces G{sub 0}/G{sub 1} phase arrest and apoptosis in human hepatic carcinoma cells

    SciTech Connect

    Han, Yuanyuan; He, Haiyun; Peng, Feng; Liu, Jiyan; Dai, Xiaoyun; Lin, Hongjun; Xu, Youzhi; Zhou, Tian; Mao, Yongqiu; Xie, Gang; Yang, Shengyong; Yu, Luoting; Yang, Li; Zhao, Yinglan

    2012-05-18

    Highlights: Black-Right-Pointing-Pointer SKLB70326 is a novel compound and has activity of anti-HCC. Black-Right-Pointing-Pointer SKLB70326 induces cell cycle arrest and apoptosis in HepG2 cells. Black-Right-Pointing-Pointer SKLB70326 induces G{sub 0}/G{sub 1} phase arrest via inhibiting the activity of CDK2, CDK4 and CDK6. Black-Right-Pointing-Pointer SKLB70326 induces apoptosis through the intrinsic pathway. -- Abstract: We previously reported the potential of a novel small molecule 3-amino-6-(3-methoxyphenyl)thieno[2.3-b]pyridine-2-carboxamide (SKLB70326) as an anticancer agent. In the present study, we investigated the anticancer effects and possible mechanisms of SKLB70326 in vitro. We found that SKLB70326 treatment significantly inhibited human hepatic carcinoma cell proliferation in vitro, and the HepG2 cell line was the most sensitive to its treatment. The inhibition of cell proliferation correlated with G{sub 0}/G{sub 1} phase arrest, which was followed by apoptotic cell death. The SKLB70326-mediated cell-cycle arrest was associated with the downregulation of cyclin-dependent kinase (CDK) 2, CDK4 and CDK6 but not cyclin D1 or cyclin E. The phosphorylation of the retinoblastoma protein (Rb) was also observed. SKLB70326 treatment induced apoptotic cell death via the activation of PARP, caspase-3, caspase-9 and Bax as well as the downregulation of Bcl-2. The expression levels of p53 and p21 were also induced by SKLB70326 treatment. Moreover, SKLB70326 treatment was well tolerated. In conclusion, SKLB70326, a novel cell-cycle inhibitor, notably inhibits HepG2 cell proliferation through the induction of G{sub 0}/G{sub 1} phase arrest and subsequent apoptosis. Its potential as a candidate anticancer agent warrants further investigation.

  6. A novel nucleolar protein, PAPA-1, induces growth arrest as a result of cell cycle arrest at the G1 phase.

    PubMed

    Kuroda, Taruho S; Maita, Hiroshi; Tabata, Takanori; Taira, Takahiro; Kitaura, Hirotake; Ariga, Hiroyoshi; Iguchi-Ariga, Sanae M M

    2004-09-29

    We have identified a novel nucleolar protein, PAP-1-associated protein-1 (PAPA-1), after screening the interacting proteins with Pim-1-associated protein-1 (PAP-1), a protein that is a phosphorylation target of Pim-1 kinase. PAPA-1 comprises 345 amino acids with a basic amino-acid cluster. PAPA-1 was found to be localized in the nucleolus in transfected HeLa cells, and the lysine/histidine cluster was essential for nucleolar localization of PAPA-1. PAPA-1 protein and mRNA expression decreased upon serum restimulation of starvation-synchronized cells, which displayed maximum level of PAPA-1 expression at G0 and early G1 phase of the cell cycle. Ectopic expression of PAPA-1 induced growth suppression of cells, and the effect was dependent on its nucleolar localization in established HeLa cell lines that inducibly express PAPA-1 or its deletion mutant under the control of a tetracycline-inducible promoter. Furthermore, when PAPA-1-inducible HeLa cells were synchronized by thymidine, colcemid or mimosine, and then PAPA-1 was expressed, the proportion of cells at the G1 phase was obviously increased. These results suggest that PAPA-1 induces growth and cell cycle arrests at the G1 phase of the cell cycle.

  7. 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.

  8. Benzylidenetetralones, cyclic chalcone analogues, induce cell cycle arrest and apoptosis in HCT116 colorectal cancer cells.

    PubMed

    Drutovic, David; Chripkova, Martina; Pilatova, Martina; Kruzliak, Peter; Perjesi, Pal; Sarissky, Marek; Lupi, Monica; Damia, Giovanna; Broggini, Massimo; Mojzis, Jan

    2014-10-01

    Colorectal cancer is the third most common cancer in the world, with 1.2 million new cancer cases annually. Chalcones are secondary metabolite precursors of flavonoids that exhibit diverse biological activities, including antioxidant and antitumor activities. The aim of this study was to investigate the antiproliferative effect of new synthetic chalcone derivatives on HCT116 cells. (E)-2-(2',4'-dimethoxybenzylidene)-1-tetralone (Q705) was found to be the most active (IC50 = 3.44 ± 0.25 μM). Based on these results, this compound was chosen for further analysis of its biochemical and molecular mechanisms. Our results showed that Q705 inhibited the growth and clonogenicity of HCT116 cells. The results of a flow cytometric analyses suggested that this compound caused a significant cell cycle arrest in G2/M phase and increased the proportion of cells in the subG0/G1 phase, marker of apoptosis. Q705-induced apoptosis was confirmed by TdT-mediated dUTP nick end labelling (TUNEL) assay. Treatment of HCT116 cells with this chalcone significantly increased the caspase-3,-7 activity and resulted in cleavage of poly-ADP-ribose polymerase (PARP). Changes in the nuclear morphology such as chromatin condensation were also observed. These effects were associated with a decreased expression of bcl-xL and increased overall ratio of bax/bcl-xL mRNA levels. Immunofluorescence and qRT-PCR analysis revealed that Q705 induced H2AX histone modifications characteristic of DNA damage, disruption of microtubule organization and downregulation of tubulins. In summary, these results suggest that the cyclic chalcone analogue Q705 has potential as a new compound for colorectal cancer therapy.

  9. Preclinical Activity of Simvastatin Induces Cell Cycle Arrest in G1 via Blockade of Cyclin D-Cdk4 Expression in Non-Small Cell Lung Cancer (NSCLC)

    PubMed Central

    Liang, Yu-Wei; Chang, Chi-Chang; Hung, Chao-Ming; Chen, Tzu-Yu; Huang, Tzuu-Yuan; Hsu, Yi-Chiang

    2013-01-01

    Lung cancer is the most common cause of cancer-related death. Nonetheless, a decrease in overall incidence and mortality has been observed in the last 30 years due to prevention strategies and improvements in the use of chemotherapeutic agents. In recent studies, Simvastatin (SIM) has demonstrated anti-tumor activity, as well as potent chemopreventive action. As an inhibitor of 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMG-CoA), SIM has been shown to stimulate apoptotic cell death. In this study, an MTT assay revealed the cytotoxic activity of SIM against human large cell lung cancer (Non-small cell lung cancer; NSCLC) cells (NCI-H460); however, induced apoptosis was not observed in NCI-H460 cells. Protein expression levels of cell cycle regulating proteins Cdk4, Cyclin D1, p16 and p27 were markedly altered by SIM. Collectively, our results indicate that SIM inhibits cell proliferation and arrests NCI-H460 cell cycle progression via inhibition of cyclin-dependent kinases and cyclins and the enhancement of CDK inhibitors p16 and p27. Our findings suggest that, in addition to the known effects on hypercholesterolemia therapy, SIM may also provide antitumor activity in established NSCLC. PMID:23481641

  10. 7-Epiclusianone, a Benzophenone Extracted from Garcinia brasiliensis (Clusiaceae), Induces Cell Cycle Arrest in G1/S Transition in A549 Cells.

    PubMed

    Ionta, Marisa; Ferreira-Silva, Guilherme A; Niero, Evandro L; Costa, Éderson D'Martin; Martens, Adam A; Rosa, Welton; Soares, Marisi G; Machado-Santelli, Gláucia M; Lago, João Henrique G; Santos, Marcelo H

    2015-07-15

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

  11. 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

  12. Aloe-emodin induced in vitro G2/M arrest of cell cycle in human promyelocytic leukemia HL-60 cells.

    PubMed

    Chen, H C; Hsieh, W T; Chang, W C; Chung, J G

    2004-08-01

    In this study, we have evaluated the chemopreventive role of aloe-emodin in human promyelocytic leukemia HL-60 cells in vitro by studying the regulation of proliferation, cell cycle and apoptosis. Aloe-emodin inhibited cell proliferation and induced G2/M arrest and apoptosis in HL-60 cells. Investigation of the levels of cyclins B1, E and A by immunoblot analysis showed that cyclin E level was unaffected, whereas cyclin B1 and A levels increased with aloe-emodin in HL-60 cells. Investigation of the levels of cyclin-dependent kinases, Cdk1 and 2, showed increased levels of Cdk1 but the levels of Cdk2 were not effected with aloe-emodin in HL-60 cells. The levels of p27 were increased after HL-60 cells were cotreated with various concentrations of aloe-emodin. The increase of the levels of p27 may be the major factor for aloe-emodin to cause G2/M arrest in these examined cells. Flow cytometric assays and DNA fragmentation gel electrophoresis also confirmed aloe-emodin induced apoptosis in HL-60 cells. The levels of caspase-3 were increased after HL-60 cells were cotreated with 10 microM aloe-emodin for 12, 24, 48, and 72 hours. Taken together, aloe-emodin therefore appears to exert its anticarcinogenesis properties by inhibiting proliferation and inducing cell cycle arrest and apoptosis underwent activation of caspase-3 in human leukemia HL-60 cells.

  13. Thoc1 inhibits cell growth via induction of cell cycle arrest and apoptosis in lung cancer cells.

    PubMed

    Wan, Jianmei; Zou, Shitao; Hu, Mengshang; Zhu, Ran; Xu, Jiaying; Jiao, Yang; Fan, Saijun

    2014-06-01

    THO complex 1 (Thoc1) is a human nuclear matrix protein that binds to the retinoblastoma tumor suppressor retinoblastoma protein (pRb). While some studies suggest that Thoc1 has characteristics of a tumor suppressor protein, whether Thoc1 can inhibit lung cancer cell growth is not clear. In the present study, we observed that Thoc1 is lowly expressed in the lung cancer cell lines SPC-A1 and NCI-H1975. Then, we investigated the potential effects of Thoc1 on lung cancer cell proliferation, cell cycle and apoptosis after stable transfection of these lines with a Thoc1 expression vector. We found that overexpression of Thoc1 can inhibit cell proliferation, induce G2/M cell cycle arrest and promote apoptosis. Further investigation indicated that overexpression of Thoc1 is involved in the inhibition of cell cycle-related proteins cyclin A1 and B1 and of pro-apoptotic factors Bax and caspase-3. In vivo experiments showed that tumors overexpressing Thoc1 display a slower growth rate than the control xenografts and show reduced expression of the protein Ki-67, which localized on the nuclear membrane. Taken together, our data show that in lung cancer cells, Thoc1 inhibits cell growth through induction of cell cycle arrest and apoptosis. These results indicate that Thoc1 may be used as a novel therapeutic target for human lung cancer treatment.

  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. Rhizoma Paridis Saponins Induces Cell Cycle Arrest and Apoptosis in Non-Small Cell Lung Carcinoma A549 Cells

    PubMed Central

    Zhang, Jue; Yang, Yixi; Lei, Lei; Tian, Mengliang

    2015-01-01

    Background As a traditional Chinese medicine herb, Chonglou (Paris polyphylla var. chinensis) has been used as anticancer medicine in China in recent decades, as it can induce cell cycle arrest and apoptosis in numerous cancer cells. The saponins extract from the rhizoma of Chonglou [Rhizoma Paridis saponins (RPS)] is known as the main active component for anticancer treatment. However, the molecular mechanism of the anticancer effect of RPS is unknown. Material/Methods The present study evaluated the effect of RPS in non-small-cell lung cancer (NSCLC) A549 cells using the 3-(4,5-dimethylthiazol-2-yl) -2,5-diphenyl tetrazolium bromide (MTT) assay and flow cytometry. Subsequently, the expression of several genes associated with cell cycle and apoptosis were detected by reverse transcription-quantitative polymerase chain reaction (qRT-PCR) and Western blotting. Results RPS was revealed to inhibit cell growth, causing a number of cells to accumulate in the G 1 phase of the cell cycle, leading to apoptosis. In addition, the effect was dose-dependent. Moreover, the results of qRT-PCR and Western blotting showed that p53 and cyclin-dependent kinase 2 (CDK2) were significantly downregulated, and that BCL2, BAX, and p21 were upregulated, by RPS treatment. Conclusions We speculated that the RPS could act on a pathway, including p53, p21, BCL2, BAX, and CDK2, and results in G1 cell cycle arrest and apoptosis in NSCLC cells. PMID:26311066

  16. Resveratrol inhibits oral squamous cell carcinoma through induction of apoptosis and G2/M phase cell cycle arrest.

    PubMed

    Yu, Xiao-Dong; Yang, Jing-Lei; Zhang, Wan-Lin; Liu, Dong-Xu

    2016-03-01

    The present study was performed to investigate the effect of resveratrol (trans-3,4',5-trihydroxystilbene) present as a natural phytoalexin in grapes, peanuts, and red wine on oral squamous cancer cell lines, SCC-VII, SCC-25, and YD-38. MTS assay and flow cytometry, respectively, were used for the analysis of inhibition of cell proliferation and apoptosis. Western blot analysis was performed to examine the effect of resveratrol on the expression of proteins associated with cell cycle regulation. The results revealed a concentration- and time-dependent inhibition of proliferation in all the three tested cell lines on treatment with resveratrol. The IC50 of resveratrol for SCC-VII, SCC-25, and YD-38 cell lines was found to be 0.5, 0.7, and 1.0 μg/ml, respectively, after 48-h treatment. Examination of the cell cycle analysis showed that resveratrol treatment induced cell cycle arrest in the G2/M phase and enhanced the expression of phospho-cdc2 (Tyr 15), cyclin A2, and cyclin B1 in the oral squamous cell carcinoma (OSCC) cells. It also caused a marked increase in the percentage of apoptotic cells as revealed by the fluorescence-activated cell sorting analysis. Thus, resveratrol exhibits inhibitory effect on the proliferation of OSCC oral cancer cells through the induction of apoptosis and G2/M phase cell cycle arrest.

  17. Kelussia odoratissima Mozaff. activates intrinsic pathway of apoptosis in breast cancer cells associated with S phase cell cycle arrest via involvement of p21/p27 in vitro and in vivo

    PubMed Central

    Karimian, Hamed; Arya, Aditya; Fadaeinasab, Mehran; Razavi, Mahboubeh; Hajrezaei, Maryam; Karim Khan, Ataul; Mohd Ali, Hapipah; Abdulla, Mahmood Ameen; Noordin, Mohamad Ibrahim

    2017-01-01

    Background The aim of this study was to evaluate the anticancer potential of Kelussia odoratissima. Several in vitro and in vivo biological assays were applied to explore the direct effect of an extract and bioactive compound of this plant against breast cancer cells and its possible mechanism of action. Materials and methods K. odoratissima methanol extract (KME) was prepared, and MTT assay was used to evaluate the cytotoxicity. To identify the cytotoxic compound, a bioassay-guided investigation was performed on methanol extract. 8-Hydroxy-ar-turmerone was isolated as a bioactive compound. In vivo study was performed in the breast cancer rat model. LA7 cell line was used to induce the breast tumor. Histopathological and expression changes of PCNA, Bcl-2, Bax, p27 and p21 and caspase-3 were examined. The induction of apoptosis was tested using Annexin V-fluorescein isothiocyanate (FITC) assay. To confirm the intrinsic pathway of apoptosis, caspase-7 and caspase-9 assays were utilized. In addition, cell cycle arrest was evaluated. Results Our results demonstrated that K. odoratissima has an obvious effect on the arrest of proliferation of cancer cells. It induced apoptosis, transduced the cell death signals, decreased the threshold of mitochondrial membrane potential (MMP), upregulated Bax and downregulated Bcl-2. Conclusion This study demonstrated that K. odoratissima exhibits antitumor activity against breast cancer cells via cell death and cell cycle arrest. PMID:28203057

  18. Serotonin and sudden death: differential effects of serotonergic drugs on seizure-induced respiratory arrest in DBA/1 mice.

    PubMed

    Faingold, Carl L; Kommajosyula, Srinivasa P; Long, X; Plath, Kristin; Randall, Marcus

    2014-08-01

    In the DBA/1 mouse model of sudden unexpected death in epilepsy (SUDEP), administration of a selective serotonin (5-HT) reuptake inhibitor (SSRI), fluvoxamine, completely suppressed seizure-induced respiratory arrest (S-IRA) at 30 min after administration (i.p.) in a dose-related manner without blocking audiogenic seizures (AGSz), but another SSRI, paroxetine, reduced S-IRA but with a delayed (24 h) onset and significant toxicity. A serotonin-norepinephrine reuptake inhibitor, venlafaxine, reduced S-IRA incidence, but higher doses were ineffective. A selective 5-HT7 agonist, AS-19, was totally ineffective in reducing S-IRA. In developing DBA/1 mice that had not previously experienced AGSz, administration of a nonselective 5-HT antagonist, cyproheptadine, induced a significantly greater incidence of S-IRA than that of saline. This study confirms that certain drugs that enhance the activation of 5-HT receptors are able to prevent S-IRA, but not all serotonergic drugs are equally effective, which may be relevant to the potential use of these drugs for SUDEP prevention. Serotonergic antagonists may be problematic in patients with epilepsy.

  19. Telomerase Cajal body protein 1 depletion inhibits telomerase trafficking to telomeres and induces G1 cell cycle arrest in A549 cells.

    PubMed

    Yuan, Ping; Wang, Zhitian; Lv, Wang; Pan, Hui; Yang, Yunhai; Yuan, Xiaoshuai; Hu, Jian

    2014-09-01

    Telomerase Cajal body protein 1 (TCAB1) is a telomerase holoenzyme, which is markedly enriched in Cajal bodies (CBs) and facilitates the recruitment of telomerase to CBs in the S phase of the cell cycle. This recruitment is dependent on TCAB1 binding to a telomerase RNA component. The majority of cancer cells are able to grow indefinitely due to telomerase and its mechanism of trafficking to telomeres. In the present study, a certain level of TCAB1 expression in A549 human lung cells was identified and TCAB1 knockdown exhibited a potent antiproliferative effect on these cells, which was coupled with a decrease in the cell density and activity of the cellular enzymes. In addition, TCAB1-depletion was demonstrated to inhibit telomerase trafficking to telomeres in the A549 cells, leading to subsequent G1 cell cycle arrest without inducing apoptotic cell death. Overall, these observations indicated that TCAB1 may be essential for A549 cell proliferation and cell cycle regulation, and may be a potential candidate for the development of a therapeutic target for lung adenocarcinomas.

  20. Tumor cell "dead or alive": caspase and survivin regulate cell death, cell cycle and cell survival.

    PubMed

    Suzuki, A; Shiraki, K

    2001-04-01

    Cell death and cell cycle progression are two sides of the same coin, and these two different phenomenons are regulated moderately to maintain the cellular homeostasis. Tumor is one of the disease states produced as a result of the disintegrated regulation and is characterized as cells showing an irreversible progression of cell cycle and a resistance to cell death signaling. Several investigations have been performed for the understanding of cell death or cell cycle, and cell death research has remarkably progressed in these 10 years. Caspase is a nomenclature referring to ICE/CED-3 cysteine proteinase family and plays a central role during cell death. Recently, several investigations raised some possible hypotheses that caspase is also involved in cell cycle regulation. In this issue, therefore, we review the molecular basis of cell death and cell cycle regulated by caspase in tumor, especially hepatocellular carcinoma cells.

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

    PubMed

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

    2015-06-19

    Two new xanthones, cowaxanthones G (1) and H (2), and 23 known analogues were isolated from an acetone extract of the leaves of Garcinia cowa. The isolated compounds were evaluated for cytotoxicity against three cancer cell lines and immortalized HL7702 normal liver cells, whereby compounds 1, 5, 8, and 15-17 exhibited significant cytotoxicity. Cell cycle analysis using flow cytometry showed that 5 induced cell cycle arrest at the S phase in a dose-dependent manner, 1 and 16 at the G2/M phase, and 17 at the G1 phase, while 16 and 17 induced apoptosis. Moreover, autophagy analysis by GFP-LC3 puncta formation and western blotting suggested that 17 induced autophagy. Taken together, our results suggest that these xanthones possess anticancer activities targeting cell cycle, apoptosis, and autophagy signaling pathways.

  2. Ammodytoxin, a secretory phospholipase A2, inhibits G2 cell-cycle arrest in the yeast Saccharomyces cerevisiae.

    PubMed

    Petrovic, Uros; Sribar, Jernej; Matis, Maja; Anderluh, Gregor; Peter-Katalinić, Jasna; Krizaj, Igor; Gubensek, Franc

    2005-10-15

    Ammodytoxin (Atx), an sPLA2 (secretory phospholipase A2), binds to g and e isoforms of porcine 14-3-3 proteins in vitro. 14-3-3 proteins are evolutionarily conserved eukaryotic regulatory proteins involved in a variety of biological processes, including cell-cycle regulation. We have now shown that Atx binds to yeast 14-3-3 proteins with an affinity similar to that for the mammalian isoforms. Thus yeast Saccharomyces cerevisiae can be used as a model eukaryotic cell, which lacks endogenous phospholipases A2, to assess the in vivo relevance of this interaction. Atx was expressed in yeast cells and shown to be biologically active inside the cells. It inhibited G2 cell-cycle arrest in yeast, which is regulated by 14-3-3 proteins. Interference with the cell cycle indicates a possible mechanism by which sPLA2s are able to cause the opposing effects, proliferation and apoptosis, in mammalian cells.

  3. Ellagic acid induces cell cycle arrest and apoptosis through TGF-β/Smad3 signaling pathway in human breast cancer MCF-7 cells.

    PubMed

    Chen, Hong-Sheng; Bai, Ming-Han; Zhang, Tao; Li, Guo-Dong; Liu, Ming

    2015-04-01

    Breast cancer represents the second leading cause of cancer-related deaths among women worldwide and preventive therapy could reverse or delay the devastating impact of this disease. Ellagic acid (EA), a dietary flavonoid polyphenol which is present in abundance in pomegranate, muscadine grapes, walnuts and strawberries, has been shown to inhibit cancer cells proliferation and induce apoptosis. Here, we investigated the growth inhibitory effects of EA on MCF-7 breast cancer cells. In the present study, we first found that EA inhibits the proliferation of MCF-7 breast cancer cells mainly mediated by arresting cell cycle in the G0/G1 phase. Moreover, gene expression profiling of MCF-7 breast cancer cell line treated with EA for 6, 12 and 24 h was performed using cDNA microarray. A total of 4,738 genes were found with a >2.0-fold change after 24 h of EA treatment. Among these genes, 2,547 were downregulated and 2,191 were upregulated. Furthermore, the changes of 16 genes, which belong to TGF-β/Smads signaling pathway, were confirmed by real-time RT-PCR and/or western blot analysis. TGF-β/Smads signaling pathway was found as the potential molecular mechanism of EA to regulate breast cancer cell cycle arrest in vitro. Therefore, the regulation of TGF-β/Smads pathway in breast cancer cells could be a novel therapeutic approach for the treatment of patients with breast cancer. Further studies with in vitro models, as well as an analysis of additional human samples, are still needed to confirm the molecular mechanisms of EA in inhibition or prevention of breast cancer growth.

  4. Cloning and sequence analysis of the Saccharomyces cerevisiae RAD9 gene and further evidence that its product is required for cell cycle arrest induced by DNA damage.

    PubMed Central

    Schiestl, R H; Reynolds, P; Prakash, S; Prakash, L

    1989-01-01

    Procaryotic and eucaryotic cells possess mechanisms for arresting cell division in response to DNA damage. Eucaryotic cells arrest division in the G2 stage of the cell cycle, and various observations suggest that this arrest is necessary to ensure the completion of repair of damaged DNA before the entry of cells into mitosis. Here, we provide evidence that the Saccharomyces cerevisiae RAD9 gene, mutations of which confer sensitivity to DNA-damaging agents, is necessary for the cell cycle arrest phenomenon. Our studies with the rad9 delta mutation show that RAD9 plays a role in the cell cycle arrest of methyl methanesulfonate-treated cells and is absolutely required for the cell cycle arrest in the temperature-sensitive cdc9 mutant, which is defective in DNA ligase. At the restrictive temperature, cell cycle progression of cdc9 cells is blocked sometime after the DNA chain elongation step, whereas cdc9 rad9 delta cells do not arrest at this point and undergo one or two additional divisions. Upon transfer from the restrictive to the permissive temperature, a larger proportion of the cdc9 cells than of the cdc9 rad9 delta cells forms viable colonies, indicating that RAD9-mediated cell cycle arrest allows for proper ligation of DNA breaks before the entry of cells into mitosis. The rad9 delta mutation does not affect the frequency of spontaneous or UV-induced mutation and recombination, suggesting that RAD9 is not directly involved in mutagenic or recombinational repair processes. The RAD9 gene encodes a transcript of approximately 4.2 kilobases and a protein of 1,309 amino acids of Mr 148,412. We suggest that RAD9 may be involved in regulating the expression of genes required for the transition from G2 to mitosis. Images PMID:2664461

  5. Nickel chloride (NiCl2) in hepatic toxicity: apoptosis, G2/M cell cycle arrest and inflammatory response

    PubMed Central

    Guo, Hongrui; Cui, Hengmin; Fang, Jing; Zuo, Zhicai; Deng, Junliang; Wang, Xun; Zhao, Ling; Chen, Kejie; Deng, Jie

    2016-01-01

    Up to now, the precise mechanism of Ni toxicology is still indistinct. Our aim was to test the apoptosis, cell cycle arrest and inflammatory response mechanism induced by NiCl2 in the liver of broiler chickens. NiCl2 significantly increased hepatic apoptosis. NiCl2 activated mitochondria-mediated apoptotic pathway by decreasing Bcl-2, Bcl-xL, Mcl-1, and increasing Bax, Bak, caspase-3, caspase-9 and PARP mRNA expression. In the Fas-mediated apoptotic pathway, mRNA expression levels of Fas, FasL, caspase-8 were increased. Also, NiCl2 induced ER stress apoptotic pathway by increasing GRP78 and GRP94 mRNA expressions. The ER stress was activated through PERK, IRE1 and ATF6 pathways, which were characterized by increasing eIF2α, ATF4, IRE1, XBP1 and ATF6 mRNA expressions. And, NiCl2 arrested G2/M phase cell cycle by increasing p53, p21 and decreasing cdc2, cyclin B mRNA expressions. Simultaneously, NiCl2 increased TNF-α, IL-1β, IL-6, IL-8 mRNA expressions through NF-κB activation. In conclusion, NiCl2 induces apoptosis through mitochondria, Fas and ER stress-mediated apoptotic pathways and causes cell cycle G2/M phase arrest via p53-dependent pathway and generates inflammatory response by activating NF-κB pathway. PMID:27824316

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

    PubMed

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

    2013-12-15

    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.

  7. Photodynamic therapy results in induction of WAF1/CIP1/P21 leading to cell cycle arrest and apoptosis.

    PubMed

    Ahmad, N; Feyes, D K; Agarwal, R; Mukhtar, H

    1998-06-09

    Photodynamic therapy (PDT) is a promising new modality that utilizes a combination of a photosensitizing chemical and visible light for the management of a variety of solid malignancies. The mechanism of PDT-mediated cell killing is not well defined. We investigated the involvement of cell cycle regulatory events during silicon phthalocyanine (Pc4)-PDT-mediated apoptosis in human epidermoid carcinoma cells A431. PDT resulted in apoptosis, inhibition of cell growth, and G0-G1 phase arrest of the cell cycle, in a time-dependent fashion. Western blot analysis revealed that PDT results in an induction of the cyclin kinase inhibitor WAF1/CIP1/p21, and a down-regulation of cyclin D1 and cyclin E, and their catalytic subunits cyclin-dependent kinase (cdk) 2 and cdk6. The treatment also resulted in a decrease in kinase activities associated with all the cdks and cyclins examined. PDT also resulted in (i) an increase in the binding of cyclin D1 and cdk6 toward WAF1/CIP1/p21, and (ii) a decrease in the binding of cyclin D1 toward cdk2 and cdk6. The binding of cyclin E and cdk2 toward WAF1/CIP1/p21, and of cyclin E toward cdk2 did not change by the treatment. These data suggest that PDT-mediated induction of WAF1/CIP1/p21 results in an imposition of artificial checkpoint at G1 --> S transition thereby resulting in an arrest of cells in G0-G1 phase of the cell cycle through inhibition in the cdk2, cdk6, cyclin D1, and cyclin E. We suggest that this arrest is an irreversible process and the cells, unable to repair the damages, ultimately undergo apoptosis.

  8. Induction of cell cycle arrest and apoptosis in HT-29 human colon cancer cells by the dietary compound luteolin.

    PubMed

    Lim, Do Y; Jeong, Yoonhwa; Tyner, Angela L; Park, Jung H Y

    2007-01-01

    Luteolin is 3',4',5,7-tetrahydroxyflavone found in celery, green pepper, and perilla leaf that inhibits tumorigenesis in animal models. We examined luteolin-mediated regulation of cell cycle progression and apoptosis in the HT-29 human colon cancer cell line. Luteolin decreased DNA synthesis and viable HT-29 cell numbers in a concentration-dependent manner. It inhibited cyclin-dependent kinase (CDK)4 and CDK2 activity, resulting in G1 arrest with a concomitant decrease of phosphorylation of retinoblastoma protein. Activities of CDK4 and CDK2 decreased within 2 h after luteolin treatment, with a 38% decrease in CDK2 activity (P < 0.05) observed in cells treated with 40 micromol/l luteolin. Luteolin inhibited CDK2 activity in a cell-free system, suggesting that it directly inhibits CDK2. Cyclin D1 levels decreased after luteolin treatment, although no changes in expression of cyclin A, cyclin E, CDK4, or CDK2 were detected. Luteolin also promoted G2/M arrest at 24 h posttreatment by downregulating cyclin B1 expression and inhibiting cell division cycle (CDC)2 activity. Luteolin promoted apoptosis with increased activation of caspases 3, 7, and 9 and enhanced poly(ADP-ribose) polymerase cleavage and decreased expression of p21(CIP1/WAF1), survivin, Mcl-1, Bcl-x(L), and Mdm-2. Decreased expression of these key antiapoptotic proteins could contribute to the increase in p53-independent apoptosis that was observed in HT-29 cells. We demonstrate that luteolin promotes both cell cycle arrest and apoptosis in the HT-29 colon cancer cell line, providing insight about the mechanisms underlying its antitumorigenic activities.

  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. Disease and Carrier Isolates of Neisseria meningitidis Cause G1 Cell Cycle Arrest in Human Epithelial Cells

    PubMed Central

    von Papen, Michael; Oosthuysen, Wilhelm F.; Becam, Jérôme; Claus, Heike

    2016-01-01

    Microbial pathogens have developed several mechanisms to modulate and interfere with host cell cycle progression. In this study, we analyzed the effect of the human pathogen Neisseria meningitidis on the cell cycle of epithelial cells. Two pathogenic isolates, as well as two carrier isolates, were tested for their ability to adhere to and invade into the epithelial cell lines Detroit 562 and NP69 and to modulate the cell cycle. We found that all isolates adhered equally well to both Detroit 562 and NP69 cells, whereas the carrier isolates were significantly less invasive. Using propidium iodide staining and 5-ethynyl-2′-deoxyuridine pulse-labeling, we provide evidence that meningococcal infection arrested cells in the G1 phase of the cell cycle at 24 h postinfection. In parallel, a significant decrease of cells in the S phase was observed. Interestingly, G1-phase arrest was only induced after infection with live bacteria but not with heat-killed bacteria. By Western blotting we demonstrate that bacterial infection resulted in a decreased protein level of the cell cycle regulator cyclin D1, whereas cyclin E expression levels were increased. Furthermore, N. meningitidis infection induced an accumulation of the cyclin-dependent kinase inhibitor (CKI) p21WAF1/CIP1 that was accompanied by a redistribution of this CKI to the cell nucleus, as shown by immunofluorescence analysis. Moreover, the p27CIP1 CKI was redistributed and showed punctate foci in infected cells. In summary, we present data that N. meningitidis can interfere with the processes of host cell cycle regulation. PMID:27430269

  11. Toona Sinensis and Moschus Decoction Induced Cell Cycle Arrest in Human Cervical Carcinoma HeLa Cells

    PubMed Central

    Zhen, Hong; Zhang, Yifei; Fang, Zhijia; Huang, Zhiwei; Shi, Ping

    2014-01-01

    Toona sinensis and Moschus are two herb materials used in traditional Chinese medicine, most commonly for their various biological activities. In this study, we investigated the inhibitory effect of three decoctions from Toona sinensis, Moschus, and Toona sinensis and Moschus in combination on cell growth in several normal and cancer cell lines by cell viability assay. The results showed that the combined decoction exhibited the strongest anticancer effects, compared to two single decoctions. The observations indicated that the combined decoction did not induce cell apoptosis and autophagy in HeLa cells by fluorescence microscopy. Flow cytometry analysis revealed that the combined decoction arrested HeLa cell cycle progression in S-phase. After the decoction incubation, among 41 cell cycle related genes, eight were reduced, while five were increased in mRNA levels by real-time PCR assay. Western blotting showed that there were no apparent changes of protein levels of Cyclin E1, while P27 expression significantly declined and the levels of CDC7 and CDK7 obviously increased. The data suggest that the RB pathway is partially responsible for the decoction-induced S-phase cell cycle arrest in HeLa cells. Therefore, the combined decoction may have therapeutic potential as an anticancer formula for certain cancers. PMID:24511319

  12. 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.

  13. 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.

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

    PubMed Central

    da Silva, Tereza Cristina; Cogliati, Bruno; Latorre, Andréia Oliveira; Akisue, Gokithi; Nagamine, Márcia Kazumi; Haraguchi, Mitsue; Hansen, Daiane; Sanches, Daniel Soares; Dagli, Maria Lúcia Zaidan

    2015-01-01

    Hebanthe paniculata roots (formerly Pfaffia paniculata and popularly known as Brazilian ginseng) show antineoplastic, chemopreventive, and antiproliferative properties. Functional properties of these roots and their extracts are usually attributed to the pfaffosidic fraction, which is composed mainly by pfaffosides A–F. However, the therapeutic potential of this fraction in cancer cells is not yet entirely understood. This study aimed to analyze the antitumoral effects of the purified pfaffosidic fraction or saponinic fraction on the human hepatocellular carcinoma HepG2 cell line. Cellular viability, proliferation, and apoptosis were evaluated, respectively, by MTT assay, BrdU incorporation, activated caspase-3 immunocytochemistry, and DNA fragmentation assay. Cell cycle was analyzed by flow cytometry and the cell cycle-related proteins were analyzed by quantitative PCR and Western blot. The cells exposed to pfaffosidic fraction had reduced viability and cellular growth, induced G2/M at 48 h or S at 72 h arrest, and increased sub-G1 cell population via cyclin E downregulation, p27KIP1 overexpression, and caspase-3-induced apoptosis, without affecting the DNA integrity. Antitumoral effects of pfaffosidic fraction from H. paniculata in HepG2 cells originated by multimechanisms of action might be associated with cell cycle arrest in the S phase, by CDK2 and cyclin E downregulation and p27KIP1 overexpression, besides induction of apoptosis through caspase-3 activation. PMID:26075002

  15. 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

  16. 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

  17. Combined paclitaxel, cisplatin and fluorouracil therapy enhances ionizing radiation effects, inhibits migration and induces G0/G1 cell cycle arrest and apoptosis in oral carcinoma cell lines.

    PubMed

    Elias, Silvia Taveira; Borges, Gabriel Alvares; Rêgo, Daniela Fortunato; E Silva, Luis Felipe Oliveira; Avelino, Samuel; DE Matos Neto, João Nunes; Simeoni, Luiz Alberto; Guerra, Eliete Neves Silva

    2015-09-01

    Although taxels (in particular paclitaxel), cisplatin and fluorouracil (TPF) chemotherapy has been approved for use in the treatment of head and neck squamous cell carcinoma (HNSCC), little is known with regard to the cellular mechanisms of this novel drug association. In order to investigate the reaction of cells to this novel treatment, the present study aimed to examine the cytotoxic effect of TPF in HNSCC cell lines in combination with irradiation, to analyze its effect on cell cycle progression and cell death, and to evaluate its ability to alter cell migration. An MTT assay was used to determine cell viability following TPF and cisplatin treatments in two human HNSCC cell lines (FaDu and SCC-9) and one keratinocyte cell line (HaCaT). The concurrent use of TPF or cisplatin and irradiation was also analyzed. Flow cytometric analysis was utilized to determine the cell cycle distribution and to verify the induction of apoptosis. The capacity of the drugs to alter oral cancer cell migration was also evaluated using a Transwell migration assay. The results indicated that TPF and cisplatin were cytotoxic to all cell lines, and enhanced the effects of ionizing radiation. FaDu cells were significantly more sensitive to the two treatments, and TPF was more cytotoxic than cisplatin for all cells. Flow cytometric analysis revealed that TPF increased the number of cells in G0/G1 phase in the SCC-9 cell line, and indicated apoptotic cell death. The results of the Transwell assay demonstrated that TPF inhibited migration in oral carcinoma cell lines. The results of the present study indicated that TPF functions in oral carcinoma cell lines through the enhancement of ionizing radiation effects, inducing cell cycle arrest at G0/G1 and apoptosis, in addition to inhibiting migration.

  18. Extract of Saccharina japonica induces apoptosis companied by cell cycle arrest and endoplasmic reticulum stress in SK-Hep1 human hepatocellular carcinoma cells.

    PubMed

    Il Jung, Hyun; Jo, Mi Jeong; Kim, Hyung-Rak; Choi, Yung Hyun; Kim, Gun-Do

    2014-01-01

    Saccharina japonica is a family member of Phaeophyceae (brown macro-alga) and extensively cultivated in China, Japan and Korea. Here, the potential anti-cancer effect of n-hexane fraction of S. japonica was evaluated in SK-Hep1 human hepatocellular carcinoma cells. The N-hexane fraction reduced cell viability and increased the numbers of apoptotic cells in a both dose- and time-dependent manner. Apoptosis was activated by both caspase-dependent and independent pathways. The caspase-dependent cell death pathway is mediated by cell surface death receptors and activated caspase-8 amplified the apoptotic signal either through direct activation of downstream caspase-3 or pro-apoptotic proteins (Bad, Bax and Bak) subsequently leading to the release of cytochrome c. On the other hand, caspase-independent apoptosis appeared mediated by disruption of mitochondrial membrane potential and translocation of AIF to the nucleus where they induced chromatin condensation and/or large-scale DNA fragmentation. In addition, the n-hexane fraction induced endoplasmic reticulum (ER)-stress and cell cycle arrest. The results suggested that potential anti-cancer effects of n-hexane extract from S. japonica on SK-Hep1 cells.

  19. 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.

  20. 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

  1. Novel ent-Kaurane Diterpenoid from Rubus corchorifolius L. f. Inhibits Human Colon Cancer Cell Growth via Inducing Cell Cycle Arrest and Apoptosis.

    PubMed

    Chen, Xuexiang; Wu, Xian; Ouyang, Wen; Gu, Min; Gao, Zili; Song, Mingyue; Chen, Yunjiao; Lin, Yanyin; Cao, Yong; Xiao, Hang

    2017-02-13

    The tender leaves of Rubus corchorifolius L. f. have been consumed as tea for drinking in China since ancient times. In this study, a novel ent-kaurane diterpenoid was isolated and identified from R. corchorifolius L. f. leaves as ent-kaur-2-one-16β,17-dihydroxy-acetone-ketal (DEK). DEK suppressed the growth of HCT116 human colon cancer cells with an IC50 value of 40 ± 0.21 μM, while it did not cause significant growth inhibition on CCD-18Co human colonic myofibroblasts at up to100 μM. Moreover, DEK induced extensive apoptosis and S phase cell cycle arrest in the colon cancer cells. Accordingly, DEK caused profound effects on multiple signaling proteins associated with cell proliferation, cell death, and inflammation. DEK significantly upregulated the expression levels of pro-apoptotic proteins such as cleaved caspase-3, cleaved caspase-9, cleaved PARP, p53, Bax, and tumor suppressor p21(Cip1/Waf1), downregulated the levels of cell cycle regulating proteins such as cyclinD1, CDK2, and CDK4 and carcinogenic proteins such as EGFR and COX-2, and suppressed the activation of Akt. Overall, our results provide a basis for using DEK as a potential chemopreventive agent against colon carcinogenesis.

  2. Early Activation of the Kynurenine Pathway Predicts Early Death and Long‐term Outcome in Patients Resuscitated From Out‐of‐Hospital Cardiac Arrest

    PubMed Central

    Ristagno, Giuseppe; Latini, Roberto; Vaahersalo, Jukka; Masson, Serge; Kurola, Jouni; Varpula, Tero; Lucchetti, Jacopo; Fracasso, Claudia; Guiso, Giovanna; Montanelli, Alessandro; Barlera, Simona; Gobbi, Marco; Tiainen, Marjaana; Pettilä, Ville; Skrifvars, Markus B.

    2014-01-01

    Background The kynurenine pathway (KP) is the major route of tryptophan (TRP) catabolism and is activated by inflammation and after cardiac arrest in animals. We hypothesized that the KP activation level correlates with severity of post–cardiac arrest shock, early death, and long‐term outcome. Methods and Results Plasma was obtained from 245 patients enrolled in a prospective multicenter observational study in 21 intensive care units in Finland. Time to return of spontaneous circulation, lowest systolic arterial pressure, and bicarbonate during the first 24 hours were collected. A cerebral performance category of 3 to 5 defined 12‐month poor outcome. Plasma TRP and KP metabolites, kynurenine (KYN), kynurenic acid, 3‐hydroxyanthranilic acid, and the ratio of KYN to TRP were measured by liquid chromatography and mass spectrometry. All KP metabolites at intensive care unit admission were significantly higher in cardiac arrest patients with a nonshockable rhythm compared to those with a shockable rhythm, and kynurenic acid and 3‐hydroxyanthranilic acid correlated with time to return of spontaneous circulation. Patients with higher levels of KYN, KYN to TRP, kynurenic acid, and 3‐hydroxyanthranilic acid had lower 24‐hour systolic arterial pressure and bicarbonate. All KP metabolites and the ratio of KYN to TRP, but not TRP, were significantly higher in patients who died in the intensive care unit in comparison to those who survived. Multivariable logistic regression showed that high kynurenic acid (odds ratio: 1.004; 95% confidence interval: 1.001 to 1.008; P=0.014), and 3‐hydroxyanthranilic acid (odds ratio: 1.011; 95% confidence interval: 1.001 to 1.022; P=0.03) were independently associated with 12‐month poor outcome and significantly improved risk reclassification. Conclusions KP is activated early after cardiac arrest and is associated with severity of post–cardiac arrest shock, early death, and poor long‐term outcome. PMID:25092787

  3. Calotropin from Asclepias curasavica induces cell cycle arrest and apoptosis in cisplatin-resistant lung cancer cells.

    PubMed

    Mo, En-Pan; Zhang, Rong-Rong; Xu, Jun; Zhang, Huan; Wang, Xiao-Xiong; Tan, Qiu-Tong; Liu, Fang-Lan; Jiang, Ren-Wang; Cai, Shao-Hui

    2016-09-16

    Calotropin (M11), an active compound isolated from Asclepias curasavica L., was found to exert strong inhibitory and pro-apoptotic activity specifically against cisplatin-induced resistant non-small cell lung cancer (NSCLC) cells (A549/CDDP). Molecular mechanism study revealed that M11 induced cell cycle arrest at the G2/M phase through down-regulating cyclins, CDK1, CDK2 and up-regulating p53 and p21. Furthermore, M11 accelerated apoptosis through the mitochondrial apoptotic pathway which was accompanied by increase Bax/Bcl-2 ratio, decrease in mitochondrial membrane potential, increase in reactive oxygen species production, activations of caspases 3 and 9 as well as cleavage of poly ADP-ribose polymerase (PARP). The activation and phosphorylation of JNK was also found to be involved in M11-induced apoptosis, and SP610025 (specific JNK inhibitor) partially prevented apoptosis induced by M11. In contrast, all of the effects that M11 induce cell cycle arrest and apoptosis in A549/CDDP cells were not significant in A549 cells. Drugs with higher sensitivity against resistant tumor cells than the parent cells are rather rare. Results of this study supported the potential application of M11 on the non-small lung cancer (NSCLC) with cisplatin resistance.

  4. 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

  5. TEAD4-YAP interaction regulates tumoral growth by controlling cell-cycle arrest at the G1 phase.

    PubMed

    Takeuchi, Shin; Kasamatsu, Atsushi; Yamatoji, Masanobu; Nakashima, Dai; Endo-Sakamoto, Yosuke; Koide, Nao; Takahara, Toshikazu; Shimizu, Toshihiro; Iyoda, Manabu; Ogawara, Katsunori; Shiiba, Masashi; Tanzawa, Hideki; Uzawa, Katsuhiro

    2017-04-29

    TEA domain transcription factor 4 (TEAD4), which has critical functions in the process of embryonic development, is expressed in various cancers. However, the important role of TEAD4 in human oral squamous cell carcinomas (OSCCs) remain unclear. Here we investigated the TEAD4 expression level and the functional mechanism in OSCC using quantitative reverse transcriptase-polymerase chain reaction, Western blot analysis, and immunohistochemistry. Furthermore, TEAD4 knockdown model was used to evaluate cellular proliferation, cell-cycle analysis, and the interaction between TEAD4 and Yes-associated protein (YAP) which was reported to be a transcription coactivator of cellular proliferation. In the current study, we found that TEAD4 expression increased significantly in vitro and in vivo and correlated with tumoral size in OSCC patients. TEAD4 knockdown OSCC cells showed decreased cellular proliferation resulting from cell-cycle arrest in the G1 phase by down-regulation of cyclins, cyclin-dependent kinases (CDKs), and up-regulation of CDK inhibitors. We also found that the TEAD4-YAP complex in the nuclei may be related closely to transcriptions of G1 arrest-related genes. Taken together, we concluded that TEAD4 might play an important role in tumoral growth and have potential to be a therapeutic target in OSCCs.

  6. A Flavone Constituent from Myoporum bontioides Induces M-Phase Cell Cycle Arrest of MCF-7 Breast Cancer Cells.

    PubMed

    Weng, Jing-Ru; Bai, Li-Yuan; Lin, Wei-Yu; Chiu, Chang-Fang; Chen, Yu-Chang; Chao, Shi-Wei; Feng, Chia-Hsien

    2017-03-15

    Myoporum bontioides is a traditional medicinal plant in Asia with various biological activities, including anti-inflammatory and anti-bacterial characteristics. To identify the bioactive constituents from M. bontioides, a newly-identified flavone, 3,4'-dimethoxy-3',5,7-trihydroxyflavone (compound 1), along with eight known compounds, were investigated in human MCF-7 breast cancer, SCC4 oral cancer, and THP-1 monocytic leukemia cells. Among these compounds, compound 1 exhibited the strongest antiproliferative activity with half-maximal inhibitory concentration (IC50) values ranging from 3.3 μM (MCF-7) to 8.6 μM (SCC4). Flow cytometric analysis indicated that compound 1 induced G2/M cell cycle arrest in MCF-7 cells. Mechanistic evidence suggests that the G2/M arrest could be attributable to compound 1's modulatory effects on the phosphorylation and expression of numerous key signaling effectors, including cell division cycle 2 (CDC2), CDC25C, and p53. Notably, compound 1 downregulated the expression of histone deacetylase 2 (HDAC2) and HDAC4, leading to increased histone H3 acetylation and p21 upregulation. Together, these findings suggest the translational potential of compound 1 as a breast cancer treatment.

  7. 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.

  8. Induction of apoptosis and cell cycle arrest by polyvinylpyrrolidone K-30 and protective effect of alpha-tocopherol.

    PubMed

    Wang, Yu-Bao; Lou, Yang; Luo, Zhao-Feng; Zhang, Dong-Fang; Wang, Yu-Zhen

    2003-09-05

    Polyvinylpyrrolidone is a macromolecular polymer with widespread use in industry as well as in medicine for various purposes. Its effect on cells cultured in vitro, however, has not been fully investigated. To elucidate this issue, we studied the influence of PVP K-30 on cultured HeLa cells. PVP K-30 treatment produced a dose- and time-dependent toxicity to HeLa cells. Cells exposed to PVP K-30 exhibited several morphological features of apoptosis. Gel electrophoresis of DNA from PVP K-30-treated cells showed typical apoptotic ladder. And flow cytometric analysis demonstrated that PVP K-30 induced cell cycle arrest at G2/M phase and the subsequent appearance of sub-G1 population. In addition, it was shown that procaspase-3 was activated in response to PVP K-30 treatment. We also found that alpha-tocopherol efficiently protected HeLa cells from PVP K-30 cytotoxicity. This is the first demonstration that PVP K-30 could induce apoptosis in HeLa cells and cell cycle arrest at G2/M phase, and that PVP K-30 toxicity could be attenuated by alpha-tocopherol.

  9. Flavonoids from Gynostemma pentaphyllum exhibit differential induction of cell cycle arrest in H460 and A549 cancer cells.

    PubMed

    Tsui, Ko-Chung; Chiang, Tzu-Hsuan; Wang, Jinn-Shyan; Lin, Li-Ju; Chao, Wei-Chih; Chen, Bing-Huei; Lu, Jyh-Feng

    2014-10-31

    Flavonoids, containing mainly kaempferol rhamnohexoside derivatives, were extracted from Gynostemma pentaphyllum (G. pentaphyllum) and their potential growth inhibition effects against H460 non-small cell lung cancer cells was explored and compared to that on A549 cells. The extracted flavonoids were found to exhibit antiproliferation effects against H460 cells (IC50 = 50.2 μg/mL), although the IC50 of H460 is 2.5-fold that of A549 cells (IC50 = 19.8 μg/mL). Further investigation revealed that H460 cells are more susceptible to kaempferol than A549, whereas A549 cell growth is better inhibited by kaempferol rhamnohexoside derivatives as compared with H460. In addition, flavonoids from G. pentaphyllum induced cell cycle arrest at both S and G2/M phases with concurrent modulated expression of the cellular proteins cyclin A, B, p53 and p21 in A549 cells, but not H460. On the contrary, apoptosis and concomitant alteration in balance of BCL-2 and BAX expression as well as activation of caspase-3 were equally affected between both cells by flavonoid treatment. These observations strongly suggest the growth inhibition discrepancy between H460 and A549 following flavonoid treatment can be attributed to the lack of cell cycle arrest in H460 cells and the differences between H460 and A549 cells may serve as contrasting models for further mechanistic investigations.

  10. AP-2γ Induces p21 Expression, Arrests Cell Cycle, and Inhibits the Tumor Growth of Human Carcinoma Cells1

    PubMed Central

    Li, Hualei; Goswami, Prabhat C; Domann, Frederick E

    2006-01-01

    Abstract Activating enhancer-binding protein 2γ (AP-2γ) is a member of the developmentally regulated AP-2 transcription factor family that regulates the expression of many downstream genes. Whereas the effects of AP-2α overexpression on cell growth are fairly well established, the cellular effects of AP-2γ overexpression are less well studied. Our new findings show that AP-2γ significantly upregulates p21 mRNA and proteins, inhibits cell growth, and decreases clonogenic survival. Cell cycle analysis revealed that forced AP-2γ expression induced G1-phase arrest, decreased DNA synthesis, and decreased the fraction of cells in S phase. AP-2γ expression also led to cyclin D1 repression, decreased Rb phosphorylation, and decreased E2F activity in breast carcinoma cells. AP-2γ binding to the p21 promoter was observed in vivo, and the absence of growth inhibition in response to AP-2γ expression in p21 (-/-) cells demonstrated that p21 caused, at least in part, AP-2-induced cell cycle arrest. Finally, the tumor growth of human breast carcinoma cells in vivo was inhibited by the expression of AP-2γ relative to empty vector-infected cells, suggesting that AP-2γ acts as a tumor suppressor. In summary, expression of either AP-2γ or AP-2α inhibited breast carcinoma cell growth; thus, these genes may be therapeutic targets for breast cancer. PMID:16867219

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

    PubMed Central

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

    2016-01-01

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

  12. 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

  13. 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

  14. The Hog1 MAP Kinase Promotes the Recovery from Cell Cycle Arrest Induced by Hydrogen Peroxide in Candida albicans

    PubMed Central

    Correia, Inês; Alonso-Monge, Rebeca; Pla, Jesús

    2017-01-01

    Eukaryotic cell cycle progression in response to environmental conditions is controlled via specific checkpoints. Signal transduction pathways mediated by MAPKs play a crucial role in sensing stress. For example, the canonical MAPKs Mkc1 (of the cell wall integrity pathway), and Hog1 (of the HOG pathway), are activated upon oxidative stress. In this work, we have analyzed the effect of oxidative stress induced by hydrogen peroxide on cell cycle progression in Candida albicans. Hydrogen peroxide was shown to induce a transient arrest at the G1 phase of the cell cycle. Specifically, a G1 arrest was observed, although phosphorylation of Mkc1 and Hog1 MAPKs can take place at all stages of the cell cycle. Interestingly, hog1 (but not mkc1) mutants required a longer time compared to wild type cells to resume growth after hydrogen peroxide challenge. Using GFP-labeled cells and mixed cultures of wild type and hog1 cells we were able to show that hog1 mutants progress faster through the cell cycle under standard growth conditions in the absence of stress (YPD at 37°C). Consequently, hog1 mutants exhibited a smaller cell size. The altered cell cycle progression correlates with altered expression of the G1 cyclins Cln3 and Pcl2 in hog1 cells compared to the wild type strain. In addition, Hgc1 (a hypha-specific G1 cyclin) as well as Cln3 displayed a different kinetics of expression in the presence of hydrogen peroxide in hog1 mutants. Collectively, these results indicate that Hog1 regulates the expression of G1 cyclins not only in response to oxidative stress, but also under standard growth conditions. Hydrogen peroxide treated cells did not show fluctuations in the mRNA levels for SOL1, which are observed in untreated cells during cell cycle progression. In addition, treatment with hydrogen peroxide prevented degradation of Sol1, an effect which was enhanced in hog1 mutants. Therefore, in C. albicans, the MAPK Hog1 mediates cell cycle progression in response to oxidative

  15. The Hog1 MAP Kinase Promotes the Recovery from Cell Cycle Arrest Induced by Hydrogen Peroxide in Candida albicans.

    PubMed

    Correia, Inês; Alonso-Monge, Rebeca; Pla, Jesús

    2016-01-01

    Eukaryotic cell cycle progression in response to environmental conditions is controlled via specific checkpoints. Signal transduction pathways mediated by MAPKs play a crucial role in sensing stress. For example, the canonical MAPKs Mkc1 (of the cell wall integrity pathway), and Hog1 (of the HOG pathway), are activated upon oxidative stress. In this work, we have analyzed the effect of oxidative stress induced by hydrogen peroxide on cell cycle progression in Candida albicans. Hydrogen peroxide was shown to induce a transient arrest at the G1 phase of the cell cycle. Specifically, a G1 arrest was observed, although phosphorylation of Mkc1 and Hog1 MAPKs can take place at all stages of the cell cycle. Interestingly, hog1 (but not mkc1) mutants required a longer time compared to wild type cells to resume growth after hydrogen peroxide challenge. Using GFP-labeled cells and mixed cultures of wild type and hog1 cells we were able to show that hog1 mutants progress faster through the cell cycle under standard growth conditions in the absence of stress (YPD at 37°C). Consequently, hog1 mutants exhibited a smaller cell size. The altered cell cycle progression correlates with altered expression of the G1 cyclins Cln3 and Pcl2 in hog1 cells compared to the wild type strain. In addition, Hgc1 (a hypha-specific G1 cyclin) as well as Cln3 displayed a different kinetics of expression in the presence of hydrogen peroxide in hog1 mutants. Collectively, these results indicate that Hog1 regulates the expression of G1 cyclins not only in response to oxidative stress, but also under standard growth conditions. Hydrogen peroxide treated cells did not show fluctuations in the mRNA levels for SOL1, which are observed in untreated cells during cell cycle progression. In addition, treatment with hydrogen peroxide prevented degradation of Sol1, an effect which was enhanced in hog1 mutants. Therefore, in C. albicans, the MAPK Hog1 mediates cell cycle progression in response to oxidative

  16. G2 cell cycle arrest, down-regulation of cyclin B, and induction of mitotic catastrophe by the flavoprotein inhibitor diphenyleneiodonium.

    PubMed

    Scaife, Robin M

    2004-10-01

    Because proliferation of eukaryotic cells requires cell cycle-regulated chromatid separation by the mitotic spindle, it is subject to regulation by mitotic checkpoints. To determine the mechanism of the antiproliferative activity of the flavoprotein-specific inhibitor diphenyleneiodonium (DPI), I have examined its effect on the cell cycle and mitosis. Similar to paclitaxel, exposure to DPI causes an accumulation of cells with a 4N DNA content. However, unlike the paclitaxel-mediated mitotic block, DPI-treated cells are arrested in the cell cycle prior to mitosis. Although DPI-treated cells can arrest with fully separated centrosomes at opposite sides of the nucleus, these centrosomes fail to assemble mitotic spindle microtubules and they do not accumulate the Thr(288) phosphorylated Aurora-A kinase marker of centrosome maturation. In contrast with paclitaxel-arrested cells, DPI impairs cyclin B1 accumulation. Release from DPI permits an accumulation of cyclin B1 and progression of the cells into mitosis. Conversely, exposure of paclitaxel-arrested mitotic cells to DPI causes a precipitous drop in cyclin B and Thr(288) phosphorylated Aurora-A levels and leads to mitotic catastrophe in a range of cancerous and noncancerous cells. Hence, the antiproliferative activity of DPI reflects a novel inhibitory mechanism of cell cycle progression that can reverse spindle checkpoint-mediated cell cycle arrest.

  17. 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

    2016-09-12

    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.

  18. 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

  19. Ferulago angulata activates intrinsic pathway of apoptosis in MCF-7 cells associated with G1 cell cycle arrest via involvement of p21/p27.

    PubMed

    Karimian, Hamed; Moghadamtousi, Soheil Zorofchian; Fadaeinasab, Mehran; Golbabapour, Shahram; Razavi, Mahboubeh; Hajrezaie, Maryam; Arya, Aditya; Abdulla, Mahmood Ameen; Mohan, Syam; Ali, Hapipah Mohd; Noordin, Mohamad Ibrahim

    2014-01-01

    Ferulago angulata is a medicinal plant that is traditionally known for its anti-inflammatory and antiulcer properties. The present study was aimed to evaluate its anticancer activity and the possible mechanism of action using MCF-7 as an in vitro model. F. angulata leaf extracts were prepared using solvents in the order of increasing polarity. As determined by MTT assay, F. angulata leaves hexane extract (FALHE) revealed the strongest cytotoxicity against MCF-7 cells with the half maximal inhibitory concentration (IC50) value of 5.3 ± 0.82 μg/mL. The acute toxicity study of FALHE provided evidence of the safety of the plant extract. Microscopic and flow cytometric analysis using annexin-V probe showed an induction of apoptosis in MCF-7 by FALHE. Treatment of MCF-7 cells with FALHE encouraged the intrinsic pathway of apoptosis, with cell death transducing signals that reduced the mitochondrial membrane potential with cytochrome c release from mitochondria to cytosol. The released cytochrome c triggered the activation of caspase-9. Meanwhile, the overexpression of caspase-8 suggested the involvement of an extrinsic pathway in the induced apoptosis at the late stage of treatment. Moreover, flow cytometric analysis showed that FALHE treatment significantly arrested MCF-7 cells in the G1 phase, which was associated with upregulation of p21 and p27 assessed by quantitative polymerase chain reaction. Immunofluorescence and the quantitative polymerase chain reaction analysis of MCF-7 cells after treatment with FALHE revealed an upregulation of Bax and a downregulation of Bcl-2 proteins. These findings proposed that FALHE suppressed the proliferation of MCF-7 cells via cell cycle arrest and the induction of apoptosis through intrinsic pathway.

  20. 2-Methoxy-5((3,4,5-trimethosyphenyl)seleninyl) phenol (SQ0814061), a novel microtubule inhibitor, evokes G2/M cell cycle arrest and apoptosis in human breast cancer cells.

    PubMed

    Xu, Jingwen; Zuo, Daiying; Qi, Huan; Shen, Qirong; Bai, Zhaoshi; Han, Mengting; Li, Zengqiang; Zhang, Weige; Wu, Yingliang

    2016-03-01

    Breast cancer is the leading cause of cancer death in women worldwide, and novel chemotherapeutic drugs with high activity and no drug resistance for treating breast cancer are needed urgently. In this study, we investigated the antitumor effect of 2-methoxy-5((3,4,5-trimethosyphenyl)seleninyl) phenol (SQ0814061), which has a strong inhibition of cell growth in MCF-7 and MDA-MB-231 cells. We demonstrated that SQ0814061 (SQ) time-dependently induced cell cycle arrest at G2/M phase and subsequently progressed into apoptosis, which is associated with microtubule depolymerization. Western blot analysis revealed that up-regulation of cyclin B1 and Aurora A was related with G2/M phase arrest in MCF-7 and MDA-MB-231 cells treatment with SQ. However, the formation of multinucleated cells after a long time exposed to SQ of MCF-7 cells delayed the cell death. In addition, apoptosis induced by SQ is correlated with the down-regulation of the PI3K-Akt-MDM2 pathway in MCF-7 and MDA-MB-231 cells. Treatment with the PI3K specific inhibitor, LY294002, increased SQ-induced cell growth inhibitory rate and apoptosis rate of MCF-7 and MDA-MB-231 cells. Moreover, SQ induced MCF-7 and MDA-MB-231 cells to generate reactive oxygen species (ROS), and the SQ-induced cell death was ROS dependent. In conclusion, all the data demonstrated that SQ exhibited its antitumor activity through disrupting the microtubule assembly, inducing cell cycle arrest and eventually apoptosis which is associated with PI3K-Akt-MDM2 pathway in MCF-7 and MDA-MB-231 cells. Therefore, the novel compound SQ is a promising microtubule inhibitor that has tremendous potentials for therapeutic treatment of human mastocarcinoma.

  1. 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.

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

    PubMed Central

    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

    ABSTRACT 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 p27Kip 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 p27Kip 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 p27Kip 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. PMID:26694515

  3. SCYL1-BP1 affects cell cycle arrest in human hepatocellular carcinoma cells via Cyclin F and RRM2.

    PubMed

    Wang, Yang; Zhi, Qiaoming; Ye, Qin; Zhou, Chengyuan; Zhang, Lei; Yan, Wei; Wu, Qun; Zhang, Di; Li, Pu; Huo, Keke

    2016-01-01

    The cell cycle is regulated via important biological mechanisms. Controlled expression of cell cycle regulatory proteins is crucial to maintain cell cycle progression. However, unbalanced protein expression leads to many diseases, such as cancer. Previous research suggests that SCYL1-BP1 function might be related to cell cycle progression and SCYL1-BP1 dysfunction to diseases through undefined mechanisms. In this research, an unbiased yeast two-hybrid screen was used to find protein(s) with potential biological relevance to SCYL1-BP1 function, and a novel interaction was recognized between SCYL1-BP1 and Cyclin F. This interaction was chosen as a paradigm to study SCYL1-BP1 function in cell cycle progression and its possible role in tumorigenesis. We found that SCYL1-BP1 binds to Cyclin F both in vivo and in vitro. SCYL1-BP1 overexpression promoted expression of the CCNF gene and simultaneously delayed Cyclin F protein degradation. SCYL1-BP1 knockdown reduced the expression of endogenous Cyclin F. It was also demonstrated in functional assays that SCYL1-BP1 overexpression induces G2/M arrest in cultured liver cells. Furthermore, SCYL1-BP1 sustained RRM2 protein expression by reducing its ubiquitination. Thus, we propose that SCYL1- BP1 affects the cell cycle through increasing steady state levels of Cyclin F and RRM2 proteins, thus constituting a dual regulatory circuit. This study provides a possible mechanism for SCYL1-BP1-mediated cell cycle regulation and related diseases.

  4. 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.

  5. Plumbagin induces cell cycle arrest and autophagy and suppresses epithelial to mesenchymal transition involving PI3K/Akt/mTOR-mediated pathway in human pancreatic cancer cells.

    PubMed

    Wang, Feng; Wang, Qi; Zhou, Zhi-Wei; Yu, Song-Ning; Pan, Shu-Ting; He, Zhi-Xu; Zhang, Xueji; Wang, Dong; Yang, Yin-Xue; Yang, Tianxing; Sun, Tao; Li, Min; Qiu, Jia-Xuan; Zhou, Shu-Feng

    2015-01-01

    Plumbagin (PLB), an active naphthoquinone compound, has shown potent anticancer effects in preclinical studies; however, the effect and underlying mechanism of PLB for the treatment of pancreatic cancer is unclear. This study aimed to examine the pancreatic cancer cell killing effect of PLB and investigate the underlying mechanism in human pancreatic cancer PANC-1 and BxPC-3 cells. The results showed that PLB exhibited potent inducing effects on cell cycle arrest in PANC-1 and BxPC-3 cells via the modulation of cell cycle regulators including CDK1/CDC2, cyclin B1, cyclin D1, p21 Waf1/Cip1, p27 Kip1, and p53. PLB treatment concentration- and time-dependently increased the percentage of autophagic cells and significantly increased the expression level of phosphatase and tensin homolog, beclin 1, and the ratio of LC3-II over LC3-I in both PANC-1 and BxPC-3 cells. PLB induced inhibition of phosphatidylinositol 3-kinase (PI3K)/protein kinase B/mammalian target of rapamycin and p38 mitogen-activated protein kinase (p38 MAPK) pathways and activation of 5'-AMP-dependent kinase as indicated by their altered phosphorylation, contributing to the proautophagic activities of PLB in both cell lines. Furthermore, SB202190, a selective inhibitor of p38 MAPK, and wortmannin, a potent, irreversible, and selective PI3K inhibitor, remarkably enhanced PLB-induced autophagy in PANC-1 and BxPC-3 cells, indicating the roles of PI3K and p38 MAPK mediated signaling pathways in PLB-induced autophagic cell death in both cell lines. In addition, PLB significantly inhibited epithelial to mesenchymal transition phenotype in both cell lines with an increase in the expression level of E-cadherin and a decrease in N-cadherin. Moreover, PLB treatment significantly suppressed the expression of Sirt1 in both cell lines. These findings show that PLB promotes cell cycle arrest and autophagy but inhibits epithelial to mesenchymal transition phenotype in pancreatic cancer cells with the involvement of PI3

  6. Effects of Hormone Agonists on Sf9 Cells, Proliferation and Cell Cycle Arrest

    PubMed Central

    Giraudo, Maeva; Califano, Jérôme; Hilliou, Frédérique; Tran, Trang; Taquet, Nathalie; Feyereisen, René; Le Goff, Gaëlle

    2011-01-01

    Methoxyfenozide and methoprene are two insecticides that mimic the action of the main hormones involved in the control of insect growth and development, 20-hydroxyecdysone and juvenile hormone. We investigated their effect on the Spodoptera frugiperda Sf9 cell line. Methoxyfenozide was more toxic than methoprene in cell viability tests and more potent in the inhibition of cellular proliferation. Cell growth arrest occurred in the G2/M phase after a methoprene treatment and more modestly in G1 after methoxyfenozide treatment. Microarray experiments and real-time quantitative PCR to follow the expression of nuclear receptors ultraspiracle and ecdysone receptor were performed to understand the molecular action of these hormone agonists. Twenty-six genes were differentially expressed after methoxyfenozide treatment and 55 genes after methoprene treatment with no gene in common between the two treatments. Our results suggest two different signalling pathways in Sf9 cells. PMID:21991338

  7. Effects of hormone agonists on Sf9 cells, proliferation and cell cycle arrest.

    PubMed

    Giraudo, Maeva; Califano, Jérôme; Hilliou, Frédérique; Tran, Trang; Taquet, Nathalie; Feyereisen, René; Le Goff, Gaëlle

    2011-01-01

    Methoxyfenozide and methoprene are two insecticides that mimic the action of the main hormones involved in the control of insect growth and development, 20-hydroxyecdysone and juvenile hormone. We investigated their effect on the Spodoptera frugiperda Sf9 cell line. Methoxyfenozide was more toxic than methoprene in cell viability tests and more potent in the inhibition of cellular proliferation. Cell growth arrest occurred in the G2/M phase after a methoprene treatment and more modestly in G1 after methoxyfenozide treatment. Microarray experiments and real-time quantitative PCR to follow the expression of nuclear receptors ultraspiracle and ecdysone receptor were performed to understand the molecular action of these hormone agonists. Twenty-six genes were differentially expressed after methoxyfenozide treatment and 55 genes after methoprene treatment with no gene in common between the two treatments. Our results suggest two different signalling pathways in Sf9 cells.

  8. Low concentrations of the toxin ophiobolin A lead to an arrest of the cell cycle and alter the intracellular partitioning of glutathione between the nuclei and cytoplasm.

    PubMed

    Locato, Vittoria; Uzal, Esther Novo; Cimini, Sara; Zonno, Maria Chiara; Evidente, Antonio; Micera, Alessandra; Foyer, Christine H; De Gara, Laura

    2015-05-01

    Ophiobolin A, a tetracyclic sesterpenoid produced by phytopathogenic fungi, is responsible for catastrophic losses in crop yield but its mechanism of action is not understood. The effects of ophiobolin A were therefore investigated on the growth and redox metabolism of Tobacco Bright Yellow-2 (TBY-2) cell cultures by applying concentrations of the toxin that did not promote cell death. At concentrations between 2 and 5 μM, ophiobolin A inhibited growth and proliferation of the TBY-2 cells, which remained viable. Microscopic and cytofluorimetric analyses showed that ophiobolin A treatment caused a rapid decrease in mitotic index, with a lower percentage of the cells at G1 and increased numbers of cells at the S/G2 phases. Cell size was not changed following treatment suggesting that the arrest of cell cycle progression was not the result of a block on cell growth. The characteristic glutathione redox state and the localization of glutathione in the nucleus during cell proliferation were not changed by ophiobolin A. However, subsequent decreases in glutathione and the re-distribution of glutathione between the cytoplasm and nuclei after mitosis occurring in control cells, as well as the profile of glutathionylated proteins, were changed in the presence of the toxin. The profile of poly ADP-ribosylated proteins were also modified by ophiobolin A. Taken together, these data provide evidence of the mechanism of ophiobolin A action as a cell cycle inhibitor and further demonstrate the link between nuclear glutathione and the cell cycle regulation, suggesting that glutathione-dependent redox controls in the nuclei prior to cell division are of pivotal importance.

  9. Gene expression profiling analysis reveals arsenic-induced cell cycle arrest and apoptosis in p53-proficient and p53-deficient cells through differential gene pathways

    SciTech Connect

    Yu Xiaozhong Robinson, Joshua F.; Gribble, Elizabeth; Hong, Sung Woo; Sidhu, Jaspreet S.; Faustman, Elaine M.

    2008-12-15

    Arsenic (As) is a well-known environmental toxicant and carcinogen as well as an effective chemotherapeutic agent. The underlying mechanism of this dual capability, however, is not fully understood. Tumor suppressor gene p53, a pivotal cell cycle checkpoint signaling protein, has been hypothesized to play a possible role in mediating As-induced toxicity and therapeutic efficiency. In this study, we found that arsenite (As{sup 3+}) induced apoptosis and cell cycle arrest in a dose-dependent manner in both p53{sup +/+} and p53{sup -/-} mouse embryonic fibroblasts (MEFs). There was, however, a distinction between genotypes in the apoptotic response, with a more prominent induction of caspase-3 in the p53{sup -/-} cells than in the p53{sup +/+} cells. To examine this difference further, a systems-based genomic analysis was conducted comparing the critical molecular mechanisms between the p53 genotypes in response to As{sup 3+}. A significant alteration in the Nrf2-mediated oxidative stress response pathway was found in both genotypes. In p53{sup +/+} MEFs, As{sup 3+} induced p53-dependent gene expression alterations in DNA damage and cell cycle regulation genes. However, in the p53{sup -/-} MEFs, As{sup 3+} induced a significant up-regulation of pro-apoptotic genes (Noxa) and down-regulation of genes in immune modulation. Our findings demonstrate that As-induced cell death occurs through a p53-independent pathway in p53 deficient cells while apoptosis induction occurs through p53-dependent pathway in normal tissue. This difference in the mechanism of apoptotic responses between the genotypes provides important information regarding the apparent dichotomy of arsenic's dual mechanisms, and potentially leads to further advancement of its utility as a chemotherapeutic agent.

  10. Targeting HGF/c-MET induces cell cycle arrest, DNA damage, and apoptosis for primary effusion lymphoma.

    PubMed

    Dai, Lu; Trillo-Tinoco, Jimena; Cao, Yueyu; Bonstaff, Karlie; Doyle, Lisa; Del Valle, Luis; Whitby, Denise; Parsons, Chris; Reiss, Krzysztof; Zabaleta, Jovanny; Qin, Zhiqiang

    2015-12-24

    Kaposi sarcoma-associated herpesvirus (KSHV) is a principal causative agent of primary effusion lymphoma (PEL) with a poor prognosis in immunocompromised patients. However, it still lacks effective treatment which urgently requires the identification of novel therapeutic targets for PEL. Here, we report that the hepatocyte growth factor (HGF)/c-MET pathway is highly activated by KSHV in vitro and in vivo. The selective c-MET inhibitor, PF-2341066, can induce PEL apoptosis through cell cycle arrest and DNA damage, and suppress tumor progression in a xenograft murine model. By using microarray analysis, we identify many novel genes that are potentially controlled by HGF/c-MET within PEL cells. One of the downstream candidates, ribonucleoside-diphosphate reductase subunit M2 (RRM2), also displays the promising therapeutic value for PEL treatment. Our findings provide the framework for development of HGF/c-MET-focused therapy and implementation of clinical trials for PEL patients.

  11. Targeting HGF/c-MET induces cell cycle arrest, DNA damage, and apoptosis for primary effusion lymphoma

    PubMed Central

    Dai, Lu; Trillo-Tinoco, Jimena; Cao, Yueyu; Bonstaff, Karlie; Doyle, Lisa; Del Valle, Luis; Whitby, Denise; Parsons, Chris; Reiss, Krzysztof; Zabaleta, Jovanny

    2015-01-01

    Kaposi sarcoma–associated herpesvirus (KSHV) is a principal causative agent of primary effusion lymphoma (PEL) with a poor prognosis in immunocompromised patients. However, it still lacks effective treatment which urgently requires the identification of novel therapeutic targets for PEL. Here, we report that the hepatocyte growth factor (HGF)/c-MET pathway is highly activated by KSHV in vitro and in vivo. The selective c-MET inhibitor, PF-2341066, can induce PEL apoptosis through cell cycle arrest and DNA damage, and suppress tumor progression in a xenograft murine model. By using microarray analysis, we identify many novel genes that are potentially controlled by HGF/c-MET within PEL cells. One of the downstream candidates, ribonucleoside-diphosphate reductase subunit M2 (RRM2), also displays the promising therapeutic value for PEL treatment. Our findings provide the framework for development of HGF/c-MET–focused therapy and implementation of clinical trials for PEL patients. PMID:26531163

  12. Decursin inhibits growth of human bladder and colon cancer cells via apoptosis, G1-phase cell cycle arrest and extracellular signal-regulated kinase activation.

    PubMed

    Kim, Wun-Jae; Lee, Se-Jung; Choi, Young Deuk; Moon, Sung-Kwon

    2010-04-01

    Decursin, a pyranocoumarin isolated from the Korean Angelica gigas root, has demonstrated anti-cancer properties. In the present study, we found that decursin inhibited cell viability in cultured human urinary bladder cancer 235J cells and colon cancer HCT116 cells. The inhibited proliferation was due to apoptotic induction, because both cells treated with decursin dose-dependently showed a sub-G1 phase accumulation and an increased cytoplasmic DNA-histone complex. Cell death caused by decursin was also associated with the down-regulation of anti-apoptotic factor Bcl-2 and the up-regulation of pro-apoptotic molecules cytochrome c, caspase 3 and Bax. Treatment of both types of cancer cells with decursin resulted in G1-phase cell cycle arrest, as revealed by FACS analyses. In addition, decursin increased protein levels of p21WAF1 with a decrease in cyclins and cyclin dependent kinases (CDKs). Furthermore, decursin induced the activation of extracellular signal-regulated kinases (ERK) in both cancer cell lines, with the notable exceptions of c-Jun N-terminal kinase (JNK) and p38 mitogen activated protein (MAP) kinase. Finally, pretreatment with ERK-specific inhibitor PD98059 reversed decursin-induced p21WAF1 expression and decursin-inhibited cell growth. Thus, these findings suggest that decursin has potential therapeutic efficacy for the treatment of bladder and colon cancer.

  13. Phenylhydroquinone induces loss of thymocytes through cell cycle arrest and apoptosis elevation in p53-dependent pathway.

    PubMed

    Nakata, Yuichiro; Nishi, Kosuke; Nishimoto, Sogo; Sugahara, Takuya

    2013-01-01

    ortho-Phenylphenol has been employed in post-harvest treatment of citrus fruits. Although o-phenylphenol has been reported to cause carcinomas in the urinary tract in rats, toxicity to the immune organs is still unknown. Herein, we report that administration of o-phenylphenol induces thymic atrophy and loss of thymocytes in female BALB/c mice. The influence seems to result from inhibition of the thymocyte development, because increased and decreased populations of the CD4⁻ CD8⁻ double-negative and CD4⁺ CD8⁺ double-positive thymocytes were observed in the o-phenylphenol-administered mice, respectively. ortho-Phenylphenol is metabolized to phenylhydroquinone by cytochrome P450 monooxygenases. Phenylhydroquinone made cell cycle of thymocytes to be arrested through reduced expression of the genes associated with G₂/M phase and through phosphorylation of p53 at Ser15. Phosphorylation of p53 at Ser15 was upregulated by activation of not only ATR but also Erk1/2 and p38, leading to increase of apoptosis. Gene expression of cytochrome P450 1A1 (CYP1A1) was promoted in thymocytes from the o-phenylphenol-administered mice. Overall, our results suggest that o-phenylphenol induces CYP1A1 expression and is metabolized into phenylhydroquinone by the expressed CYP1A1 in thymocytes. The produced phenylhydroquinone in turn induces inhibition of thymocyte development through cell cycle arrest and apoptosis in the p53-dependent pathway.

  14. 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.

  15. 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.

  16. 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.

  17. Lobaplatin arrests cell cycle progression, induces apoptosis and alters the proteome in human cervical cancer cell Line CaSki.

    PubMed

    Li, Xiaoqin; Ran, Li; Fang, Wen; Wang, Donghong

    2014-04-01

    Cervical cancer is one of the most common gynecologic tumors. There is an upward trend in the incidence. The objective of this research was to explore the effect of lobaplatin on cervical cancer CaSki cells proliferation, cell cycle and apoptosis and analysis of the differential expressed proteins of CaSki cells after exposed to lobaplatin. Our findings have shown that lobaplatin inhibits cell proliferations in human cervical cancer CaSki cells in dose- and time-dependent manner. Flow cytometry assay confirmed that lobaplatin affected cervical cancer cell survival by blocking cell cycle progression in S phase and G0/G1 phase and inducing apoptosis in dose- and time-dependent manner. Lobaplatin treatment reduced polypyrimidine tract-binding protein 2, ribose-phosphate pyrophosphokinase, hypothetical protein, terminal uridylyltransferase 7, ubiquitin specific protease 16 and heterogeneous nuclear ribonucleoprotein A2/B1 expression and increase zinc finger protein 91, zinc finger protein, C-X-C motif chemokine 10 precursor, stromal cell protein and laminin subunit alpha-4 expression. Some of the differentially expressed proteins may be associated with antitumor effect of lobaplatin. Lobaplatin showed a good antitumour activity in in vitro models of human cervical cancer cells. These results indicate that lobaplatin could be an effective chemotherapeutic agent in human cervical cancer treatment by inducing apoptosis, cell cycle arrest and changing many kinds of protein molecule expression level.

  18. Protein PSMD8 may mediate microgravity-induced cell cycle arrest

    NASA Astrophysics Data System (ADS)

    Hang, Xiaoming; Sun, Yeqing; Xu, Dan; Wu, Di; Chen, Xiaoning

    Microgravity environment of space can induce a serial of changes in cells, such as morphology alterations, cytoskeleton disorder and cell cycle disturbance. Our previous study of simulated-microgravity on zebrafish (Danio rerio) embryos demonstrated 26s proteasome non-ATPase regulatory subunit 8 (PSMD8) might be a microgravity sensitive gene. However, functional study on PSMD8 is very limited and it has not been cloned in zebrafish till now. In this study, we tried to clone PSMD8 gene in zebrafish, quantify its protein expression level in zebrafish embryos after simulated microgravity and identify its possible function in cell cycle regulation. A rotary cell culture system (RCCS) designed by national aeronautics and apace administration (NASA) of America was used to simulate microgravity. The full-length of psmd8 gene in zebrafish was cloned. Preliminary analysis on its sequence and phylogenetic tree construction were carried out subsequently. Quantitative analysis by western blot showed that PSMD8 protein expression levels were significantly increased 1.18 and 1.22 times after 24-48hpf and 24-72hpf simulated microgravity, respectively. Moreover, a significant delay on zebrafish embryo development was found in simulated-microgravity exposed group. Inhibition of PSMD8 protein in zebrafish embryonic cell lines ZF4 could block cell cycle in G1 phase, which indicated that PSMD8 may play a role in cell cycle regulation. Interestingly, simulated-microgravity could also block ZF4 cell in G1 phase. Whether it is PSMD8 mediated cell cycle regulation result in the zebrafish embryo development delay after simulated microgravity exposure still needs further study. Key Words: PSMD8; Simulated-microgravity; Cell cycle; ZF4 cell line

  19. Dissociation of centrosome replication events from cycles of DNA synthesis and mitotic division in hydroxyurea-arrested Chinese hamster ovary cells

    PubMed Central

    1995-01-01

    Relatively little is known about the mechanisms used by somatic cells to regulate the replication of the centrosome complex. Centrosome doubling was studied in CHO cells by electron microscopy and immunofluorescence microscopy using human autoimmune anticentrosome antiserum, and by Northern blotting using the cDNA encoding portion of the centrosome autoantigen pericentriolar material (PCM)-1. Centrosome doubling could be dissociated from cycles of DNA synthesis and mitotic division by arresting cells at the G1/S boundary of the cell cycle using either hydroxyurea or aphidicolin. Immunofluorescence micros-copy using SPJ human autoimmune anticentrosome antiserum demonstrated that arrested cells were able to undergo numerous rounds of centrosome replication in the absence of cycles of DNA synthesis and mitosis. Northern blot analysis demonstrated that the synthesis and degradation of the mRNA encoding PCM-1 occurred in a cell cycle-dependent fashion in CHO cells with peak levels of PCM-1 mRNA being present in G1 and S phase cells before mRNA amounts dropped to undetectable levels in G2 and M phases. Conversely, cells arrested at the G1/S boundary of the cell cycle maintained PCM-1 mRNA at artificially elevated levels, providing a possible molecular mechanism for explaining the multiple rounds of centrosome replication that occurred in CHO cells during prolonged hydroxyurea-induced arrest. The capacity to replicate centrosomes could be abolished in hydroxyurea-arrested CHO cells by culturing the cells in dialyzed serum. However, the ability to replicate centrosomes and to synthesize PCM-1 mRNA could be re- initiated by adding EGF to the dialyzed serum. This experimental system should be useful for investigating the positive and negative molecular mechanisms used by somatic cells to regulate the replication of centrosomes and for studying and the methods used by somatic cells for coordinating centrosome duplication with other cell cycle progression events. PMID:7790366

  20. Characterization of RAD9 of Saccharomyces cerevisiae and evidence that its function acts posttranslationally in cell cycle arrest after DNA damage.

    PubMed Central

    Weinert, T A; Hartwell, L H

    1990-01-01

    In eucaryotic cells, incompletely replicated or damaged chromosomes induce cell cycle arrest in G2 before mitosis, and in the yeast Saccharomyces cerevisiae the RAD9 gene is essential for the cell cycle arrest (T.A. Weinert and L. H. Hartwell, Science 241:317-322, 1988). In this report, we extend the analysis of RAD9-dependent cell cycle control. We found that both induction of RAD9-dependent arrest in G2 and recovery from arrest could occur in the presence of the protein synthesis inhibitor cycloheximide, showing that the mechanism of RAD9-dependent control involves a posttranslational mechanism(s). We have isolated and determined the DNA sequence of the RAD9 gene, confirming the DNA sequence reported previously (R. H. Schiestl, P. Reynolds, S. Prakash, and L. Prakash, Mol. Cell. Biol. 9:1882-1886, 1989). The predicted protein sequence for the Rad9 protein bears no similarity to sequences of known proteins. We also found that synthesis of the RAD9 transcript in the cell cycle was constitutive and not induced by X-irradiation. We constructed yeast cells containing a complete deletion of the RAD9 gene; the rad9 null mutants were viable, sensitive to X- and UV irradiation, and defective for cell cycle arrest after DNA damage. Although Rad+ and rad9 delta cells had similar growth rates and cell cycle kinetics in unirradiated cells, the spontaneous rate of chromosome loss (in unirradiated cells) was elevated 7- to 21-fold in rad9 delta cells. These studies show that in the presence of induced or endogenous DNA damage, RAD9 is a negative regulator that inhibits progression from G2 in order to preserve cell viability and to maintain the fidelity of chromosome transmission. Images PMID:2247073

  1. Involvement of apoptotic cell death and cell cycle perturbation in retinoic acid-induced cleft palate in mice

    SciTech Connect

    Okano, Junko . E-mail: okajun@anat1.med.kyoto-u.ac.jp; Suzuki, Shigehiko; Shiota, Kohei

    2007-05-15

    Retinoic acid (RA), a metabolite of vitamin A, plays a key role in a variety of biological processes and is essential for normal embryonic development. On the other hand, exogenous RA could cause cleft palate in offspring when it is given to pregnant animals at either the early or late phases of palatogenesis, but the pathogenetic mechanism of cleft palate caused by excess RA remains not fully elucidated. The aim of the present study was to investigate the effects of excess of RA on early palatogenesis in mouse fetuses and analyze the teratogenic mechanism, especially at the stage prior to palatal shelf elevation. We gave all-trans RA (100 mg/kg) orally to E11.5 ICR pregnant mice and observed the changes occurring in the palatal shelves of their fetuses. It was found that apoptotic cell death increased not only in the epithelium of the palatal shelves but also in the tongue primordium, which might affect tongue withdrawal movement during palatogenesis and impair the horizontal elevation of palatal shelves. In addition, RA was found to prevent the G{sub 1}/S progression of palatal mesenchymal cells through upregulation of p21 {sup Cip1}, leading to Rb hypophospholylation. Thus, RA appears to cause G{sub 1} arrest in palatal mesenchymal cells in a similar manner as in various cancer and embryonic cells. It is likely that apoptotic cell death and cell cycle disruption are involved in cleft palate formation induced by RA.

  2. Lebein, a snake venom disintegrin, suppresses human colon cancer cells proliferation and tumor-induced angiogenesis through cell cycle arrest, apoptosis induction and inhibition of VEGF expression.

    PubMed

    Zakraoui, Ons; Marcinkiewicz, Cezary; Aloui, Zohra; Othman, Houcemeddine; Grépin, Renaud; Haoues, Meriam; Essafi, Makram; Srairi-Abid, Najet; Gasmi, Ammar; Karoui, Habib; Pagès, Gilles; Essafi-Benkhadir, Khadija

    2017-01-01

    Lebein, is an heterodimeric disintegrin isolated from Macrovipera lebetina snake venom that was previously characterized as an inhibitor of ADP-induced platelet aggregation. In this study, we investigated the effect of Lebein on the p53-dependent growth of human colon adenocarcinoma cell lines. We found that Lebein significantly inhibited LS174 (p53wt), HCT116 (p53wt), and HT29 (p53mut) colon cancer cell viability by inducing cell cycle arrest through the modulation of expression levels of the tumor suppression factor p53, cell cycle regulating proteins cyclin D1, CDK2, CDK4, retinoblastoma (Rb), CDK1, and cyclin-dependent kinase inhibitors p21 and p27. Interestingly, Lebein-induced apoptosis of colon cancer cells was dependent on their p53 status. Thus, in LS174 cells, cell death was associated with PARP cleavage and the activation of caspases 3 and 8 while in HCT116 cells, Lebein induced caspase-independent apoptosis through increased expression of apoptosis inducing factor (AIF). In LS174 cells, Lebein triggers the activation of the MAPK ERK1/2 pathway through induction of reactive oxygen species (ROS). It also decreased cell adhesion and migration to fibronectin through down regulation of α5β1 integrin. Moreover, Lebein significantly reduced the expression of two angiogenesis stimulators, Vascular Endothelial Growth Factor (VEGF) and Neuropilin 1 (NRP1). It inhibited the VEGF-induced neovascularization process in the quail embryonic CAM system and blocked the development of human colon adenocarcinoma in nude mice. Overall, our work indicates that Lebein may be useful to design a new therapy against colon cancer. © 2016 Wiley Periodicals, Inc.

  3. Combined treatment of gamma-tocotrienol with statins induce mammary tumor cell cycle arrest in G1.

    PubMed

    Wali, Vikram B; Bachawal, Sunitha V; Sylvester, Paul W

    2009-06-01

    Statins and gamma-tocotrienol (a rare isoform of vitamin E) both inhibit 3-hydroxy-3-methylglutaryl-coenzyme A (HMGCoA) reductase activity and display anticancer activity. However, clinical application of statins has been limited by high dose toxicity. Previous studies showed that combined statin and gamma-tocotrienol treatment synergistically inhibits growth of highly malignant +SA mammary epithelial cells in culture. To investigate the mechanism mediating this growth inhibition, studies were conducted to determine the effect of combination low dose gamma-tocotrienol and statin treatment on +SA mammary tumor cell cycle progression. Treatment with 0.25 microM simvastatin, lovastatin, mevastatin, 10 microM pravastatin or 2.0 microM gamma-tocotrienol alone had no effect, while combined treatment of individual statins with gamma-tocotrienol significantly inhibited +SA cell proliferation during the 4-day culture period. Flow cytometric analysis demonstrated that combined treatment induced cell cycle arrest in G1. Additional studies showed that treatment with 0.25 microM simvastatin or 2 microM gamma-tocotrienol alone had no effect on the relative intracellular levels of cyclin D1, CDK2, CDK4 and CDK6, but combined treatment caused a large reduction in cyclin D1 and CDK2 levels. Combined treatments also caused a relatively large increase in p27, but had no effect on p21 and p15 levels, and resulted in a large reduction in retinoblastoma (Rb) protein phosphorylation at ser780 and ser807/811. Similar effects were observed following combined treatment of gamma-tocotrienol with low doses of lovastatin, mevastatin and pravastatin. These findings demonstrate that combination low dose statin and gamma-tocotrienol treatment induced mammary tumor cell cycle arrest at G1, resulting from an increase in p27 expression, and a corresponding decrease in cyclin D1, CDK2, and hypophosphorylation of Rb protein. These findings suggest that combined treatment of statins with gamma

  4. Pectenotoxin-2 induces G2/M phase cell cycle arrest in human breast cancer cells via ATM and Chk1/2-mediated phosphorylation of cdc25C.

    PubMed

    Moon, Dong-Oh; Kim, Mun-Ock; Nam, Taek-Jeong; Kim, Se-Kwon; Choi, Yung Hyun; Kim, Gi-Young

    2010-07-01

    Although pectenotoxin-2 (PTX-2) is known to regulate the actin depolymerization and to induce apoptosis through downregulation of telomerase activity, little is known on its effect on the cell cycle regulation. Therefore, we investigated the effects of PTX-2 on G2/M arrest in human breast cancer cells (MDA-MB-231 and MCF-7). Treatment with PTX-2 significantly suppressed cell proliferation and induced G2/M phase arrest through down-regulation of cyclin B1 and cdc2 expression, but also through phosphorylation of cdc25C. We found increased phosphorylation of ATM and Chk1/2 in a PTX-2 dose-dependent manner. Furthermore, treatment with PTX-2 increased H2O2 generation with correlated G2/M arrest. Our results showed that ATM- and Chk1/2-mediated phosphorylation of cdc25C plays a major role in G2/M arrest, but not in H2O2 generation induced by PTX-2 treatment. We also observed that PTX-2-induced cell cycle arrest was not restricted to p53 status in human breast cancer cells.

  5. 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.

  6. Rosiglitazone inhibits cell proliferation by inducing G1 cell cycle arrest and apoptosis in ADPKD cyst-lining epithelia cells.

    PubMed

    Liu, Yawei; Dai, Bing; Fu, Lili; Jia, Jieshuang; Mei, Changlin

    2010-06-01

    Abnormal proliferation is an important pathological feature of autosomal dominant polycystic kidney disease (ADPKD). Many drugs inhibiting cell proliferation have been proved to be effective in slowing the disease progression in ADPKD. Recent evidence has suggested that peroxisome proliferator-activated receptor gamma (PPARgamma) ligands have anti-neoplasm effects through inhibiting cell growth and inducing cell apoptosis in various cancer cells. In the present study, we examined the expression of PPARgamma in human ADPKD kidney tissues and cyst-lining epithelial cell line, and found that the expression of PPARgamma was greater in ADPKD kidney tissues and cyst-lining epithelial cell line than in normal kidney tissues and human kidney cortex (HKC) cell line. Rosiglitazone inhibited significantly proliferation of cyst-lining epithelial cells in a concentration- and time-dependent manner. These effects were diminished by GW9662, a specific PPARgamma antagonist. Cell cycle analysis showed a G0/G1 arrest in human ADPKD cyst-lining epithelial cells with rosiglitazone treatment. Analysis of cell cycle regulatory proteins revealed that rosiglitazone decreased the protein levels of proliferating cell nuclear antigen, pRb, cyclin D1, cyclin D2 and Cdk4 but increased the levels of p21 and p27 in a dose-dependent manner. Rosiglitazone also induced apoptosis in cyst-lining epithelial cells, which was correlated with increased bax expression and decreased bcl-2 expression. These results suggest PPARgamma agonist might serve as a promising drug for the treatment of ADPKD.

  7. Chaetocin-A histone methyltransferase inhibitor-Impairs proliferation, arrests cell cycle and induces nucleolar disassembly in Trypanosoma cruzi.

    PubMed

    Zuma, Aline Araujo; Santos, Jean de Oliveira; Mendes, Isabela; de Souza, Wanderley; Machado, Carlos Renato; Motta, Maria Cristina M

    2017-02-06

    The Trypanosomatidae family includes pathogenic species of medical and veterinary interest. Chagas disease is endemic in Latin America, and about 8 million people are infected worldwide. There is a need for more effective drugs for the acute, undetermined and chronic phases of the disease that, in addition, do not cause side effects, stimulating the search for identification of new drug targets, as well as new chemotherapeutic targets. Trypanosomatids contain characteristic structures, such as the nucleus that undergoes a closed mitosis without chromosome formation and variations of chromatin packing in the different protozoa developmental stages. The nuclear DNA is condensed by histones that suffer post-translational modifications, such as addition of methyl groups by histone methyltransferases (MHT) and addition of acetyl groups by acetyltransferases. These processes modulate gene expression and chromatin organization, which are crucial to transcription, replication, repair and recombination. In the present study, the effects of chaetocin, a HMT inhibitor, on T. cruzi epimastigote proliferation, viability, ultrastructure and cell cycle were investigated. Results indicate that chaetocin promoted irreversible inhibition of protozoa growth, evident unpacking of nuclear heterochromatin and intense nucleolus fragmentation, which is associated with parasite cell cycle arrest and RNA transcription blockage. Taken together, data obtained with chaetocin treatment stimulate the use of histone methyltransferase inhibitors against pathogenic trypanosomatids.

  8. Histological Lesions, Cell Cycle Arrest, Apoptosis and T Cell Subsets Changes of Spleen in Chicken Fed Aflatoxin-contaminated Corn

    PubMed Central

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

    2014-01-01

    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. PMID:25141002

  9. 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.

  10. Inhibition of PPARα induces cell cycle arrest and apoptosis, and synergizes with glycolysis inhibition in kidney cancer cells.

    PubMed

    Abu Aboud, Omran; Wettersten, Hiromi I; Weiss, Robert H

    2013-01-01

    Renal cell carcinoma (RCC) is the sixth most common cancer in the US. While RCC is highly metastatic, there are few therapeutics options available for patients with metastatic RCC, and progression-free survival of patients even with the newest targeted therapeutics is only up to two years. Thus, novel therapeutic targets for this disease are desperately needed. Based on our previous metabolomics studies showing alteration of peroxisome proliferator-activated receptor α (PPARα) related events in both RCC patient and xenograft mice materials, this pathway was further examined in the current study in the setting of RCC. PPARα is a nuclear receptor protein that functions as a transcription factor for genes including those encoding enzymes involved in energy metabolism; while PPARα has been reported to regulate tumor growth in several cancers, it has not been evaluated in RCC. A specific PPARα antagonist, GW6471, induced both apoptosis and cell cycle arrest at G0/G1 in VHL(+) and VHL(-) RCC cell lines (786-O and Caki-1) associated with attenuation of the cell cycle regulatory proteins c-Myc, Cyclin D1, and CDK4; this data was confirmed as specific to PPARα antagonism by siRNA methods. Interestingly, when glycolysis was blocked by several methods, the cytotoxicity of GW6471 was synergistically increased, suggesting a switch to fatty acid oxidation from glycolysis and providing an entirely novel therapeutic approach for RCC.

  11. Induction of cell cycle arrest, DNA damage, and apoptosis by nimbolide in human renal cell carcinoma cells.

    PubMed

    Hsieh, Yi-Hsien; Lee, Chien-Hsing; Chen, Hsiao-Yun; Hsieh, Shu-Ching; Lin, Chia-Liang; Tsai, Jen-Pi

    2015-09-01

    Nimbolide is a tetranortriterpenoid isolated from the leaves and flowers of Azadirachta indica which has been shown to exhibit anticancer, antioxidant, anti-inflammatory, and anti-invasive properties in a variety of cancer cells. However, the anti-tumor effect on human renal cell carcinoma (RCC) cells is unknown. In this study, we found that nimbolide treatment had a cytotoxic effect on 786-O and A-498 RCC cells in a dose-dependent manner. According to flow cytometric analysis, nimbolide treatment resulted in G2/M arrest in 786-O and A-498 cells accompanied with an increase in the phosphorylation status of p53, cdc2, cdc25c, and decreased expressions of cyclin A, cyclin B, cdc2, and cdc25c. Nimbolide also caused DNA damage in a dose-dependent manner as determined by comet assay and measurement of γ-H2AX. In addition, apoptotic cells were observed in an Annexin V-FITC/propidium iodide double-stained assay. The activities of caspase-3, -9, and poly ADP-ribose polymerase (PARP) were increased, and the expression of pro-caspase-8 was decreased in nimbolide-treated 786-O and A-498 cells. Western blot analysis revealed that the levels of intrinsic-related apoptotic proteins Bax and extrinsic-related proteins (DR5, CHOP) were significantly increased in nimbolide-treated 786-O and A-498 cells. In addition, the expressions of Bcl-2 and Mcl-1 were decreased in 786-O and A-498 cells after nimbolide treatment. We conclude that nimbolide can inhibit the growth of human RCC cells by inducing G2/M phase arrest by modulating cell cycle-related proteins and cell apoptosis by regulating intrinsic and extrinsic caspase signaling pathways. Nimbolide may be a promising therapeutic strategy for the treatment of RCC.

  12. Strategic Cell-Cycle Regulatory Features That Provide Mammalian Cells with Tunable G1 Length and Reversible G1 Arrest

    PubMed Central

    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. PMID:22558136

  13. Radiofrequency radiation (900 MHz)-induced DNA damage and cell cycle arrest in testicular germ cells in swiss albino mice.

    PubMed

    Pandey, Neelam; Giri, Sarbani; Das, Samrat; Upadhaya, Puja

    2016-10-13

    Even though there are contradictory reports regarding the cellular and molecular changes induced by mobile phone emitted radiofrequency radiation (RFR), the possibility of any biological effect cannot be ruled out. In view of a widespread and extensive use of mobile phones, this study evaluates alterations in male germ cell transformation kinetics following RFR exposure and after recovery. Swiss albino mice were exposed to RFR (900 MHz) for 4 h and 8 h duration per day for 35 days. One group of animals was terminated after the exposure period, while others were kept for an additional 35 days post-exposure. RFR exposure caused depolarization of mitochondrial membranes resulting in destabilized cellular redox homeostasis. Statistically significant increases in the damage index in germ cells and sperm head defects were noted in RFR-exposed animals. Flow cytometric estimation of germ cell subtypes in mice testis revealed 2.5-fold increases in spermatogonial populations with significant decreases in spermatids. Almost fourfold reduction in spermatogonia to spermatid turnover (1C:2C) and three times reduction in primary spermatocyte to spermatid turnover (1C:4C) was found indicating arrest in the premeiotic stage of spermatogenesis, which resulted in loss of post-meiotic germ cells apparent from testis histology and low sperm count in RFR-exposed animals. Histological alterations such as sloughing of immature germ cells into the seminiferous tubule lumen, epithelium depletion and maturation arrest were also observed. However, all these changes showed recovery to varied degrees following the post-exposure period indicating that the adverse effects of RFR on mice germ cells are detrimental but reversible. To conclude, RFR exposure-induced oxidative stress causes DNA damage in germ cells, which alters cell cycle progression leading to low sperm count in mice.

  14. Alkylphospholipids deregulate cholesterol metabolism and induce cell-cycle arrest and autophagy in U-87 MG glioblastoma cells.

    PubMed

    Ríos-Marco, Pablo; Martín-Fernández, Mario; Soria-Bretones, Isabel; Ríos, Antonio; Carrasco, María P; Marco, Carmen

    2013-08-01

    Glioblastoma is the most common malignant primary brain tumour in adults and one of the most lethal of all cancers. Growing evidence suggests that human tumours undergo abnormal lipid metabolism, characterised by an alteration in the mechanisms that regulate cholesterol homeostasis. We have investigated the effect that different antitumoural alkylphospholipids (APLs) exert upon cholesterol metabolism in the U-87 MG glioblastoma cell line. APLs altered cholesterol homeostasis by interfering with its transport from the plasma membrane to the endoplasmic reticulum (ER), thus hindering its esterification. At the same time they stimulated the synthesis of cholesterol from radiolabelled acetate and its internalisation from low-density lipoproteins (LDLs), inducing both 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR) and LDL receptor (LDLR) genes. Fluorescent microscopy revealed that these effects promoted the accumulation of intracellular cholesterol. Filipin staining demonstrated that this accumulation was not confined to the late endosome/lysosome (LE/LY) compartment since it did not colocalise with LAMP2 lysosomal marker. Furthermore, APLs inhibited cell growth, producing arrest at the G2/M phase. We also used transmission electron microscopy (TEM) to investigate ultrastructural alterations induced by APLs and found an abundant presence of autophagic vesicles and autolysosomes in treated cells, indicating the induction of autophagy. Thus our findings clearly demonstrate that antitumoural APLs interfere with the proliferation of the glioblastoma cell line via a complex mechanism involving cholesterol metabolism, cell-cycle arrest or autophagy. Knowledge of the interrelationship between these processes is fundamental to our understanding of tumoural response and may facilitate the development of novel therapeutics to improve treatment of glioblastoma and other types of cancer.

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

    PubMed

    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.

  16. Cycles Tipping the Scale between Death and Survival (=``Life")

    NASA Astrophysics Data System (ADS)

    Halberg, F.; Cornélissen, G.; Sothern, R. B.; Katinas, G. S.; Schwartzkopff, O.; Otsuka, K.

    Systematic chronobiologically interpreted ambulatory bloodpressure (BP) and heart rate (HR) monitoring (C-ABPM 7D/24H is now automatically possible; if continued around the clock over a week, this approach detects vascular variability disorders (VVDs) that include, among others, high BP itself and CHAT, short for circadian hyper-amplitude-tension. BP is never a constant ``true" (resting) value and can be more reliably diagnosed by CABPM 7d/24h as MESOR-hypertension, MH. CHAT carries a risk of hard events greater than MH and can be treated, among other VVDs, which if they coexist constitute vascular variability syndromes (VVSs). A project on The BIOsphere and the COSmos, BIOCOS (corne001@umn.edu), provides, in exchange for the data, cost-free analyses and the opportunity of obtaining monitors at a cost reduction of 80% complements the records from purely physical tools for surveilling the variable sun, by validating in the biosphere the reality of intermittent, aeolian envi ronmental spectral components that can be more consistent than their physical counterparts once they are coded in genes. C-ABPM 7D/24H indicates relevant associations of space weather with human health and ecology. Monitoring reveals, around and in living matter, a system of transdisciplinary cycles with common average periods, quantified with point-and-interval estimates of parameters. The cycles in space climate are critical in discussing global warming. The cycles' periods are described as congruent when their CIs (95\\ intervals) overlie or overlap and the amplitudes' CIs' lower limits are positive. Some congruent cycles in organisms, counterparts of the environmental day and the seasons, relate to electromagnetic radiation in the visible domain; these are the usually environmentally synchronized socio-photo-thermoperiodisms (photics). The biosphere also resonates with or is pulled or driven by nonstationary, environmental nonphotic cycles (nonphotics) -- particle emissi ons from the sun and

  17. Glucose deprivation induces G2/M transition-arrest and cell death in N-GlcNAc2-modified protein-producing renal carcinoma cells.

    PubMed

    Isono, Takahiro; Chano, Tokuhiro; Kitamura, Asuka; Yuasa, Takeshi

    2014-01-01

    Some cancer cells can survive under glucose deprivation within the microenvironment of a tumor. Recently, we reported that N-linked (β-N-acetylglucosamine)2 [N-GlcNAc2]-modified proteins induce G2/M arrest and cell death under glucose deprivation. Here, we investigated whether such a response to glucose deprivation contributes to the survival of renal cell carcinomas, which are sensitive to nutritional stress. Specifically, we analyzed seven renal carcinoma cell lines. Four of these cell lines produced N-GlcNAc2-modified proteins and led G2/M-phase arrest under glucose deprivation, leading to cell death. The remaining three cell lines did not produce N-GlcNAc2-modified proteins and undergo G1/S-phase arrest under glucose deprivation, leading to survival. The four dead cell lines displayed significant up-regulation in the UDP-GlcNAc biosynthesis pathway as well as increased phosphorylation of p53, which was not observed in the surviving three cell lines. In addition, the four dead cell lines showed prolonged up-regulated expression of ATF3, which is related to unfolded protein response (UPR), while the surviving three cell lines showed only transient up-regulation of ATF3. In this study, we demonstrated that the renal carcinoma cells which accumulate N-GlcNAc2-modified proteins under glucose deprivation do not survive with abnormaly prolonged UPR pathway. By contrast, renal carcinoma cells that do not accumulate N-GlcNAc2-modified proteins under these conditions survive. Morover, we demonstrated that buformin, a UPR inhibitor, efficiently reduced cell survival under conditions of glucose deprivation for both sensitive and resistant phenotypes. Further studies to clarify these findings will lead to the development of novel chemotherapeutic treatments for renal cancer.

  18. Glucose Deprivation Induces G2/M Transition-Arrest and Cell Death in N-GlcNAc2-Modified Protein-Producing Renal Carcinoma Cells

    PubMed Central

    Isono, Takahiro; Chano, Tokuhiro; Kitamura, Asuka; Yuasa, Takeshi

    2014-01-01

    Some cancer cells can survive under glucose deprivation within the microenvironment of a tumor. Recently, we reported that N-linked (β-N-acetylglucosamine)2 [N-GlcNAc2]-modified proteins induce G2/M arrest and cell death under glucose deprivation. Here, we investigated whether such a response to glucose deprivation contributes to the survival of renal cell carcinomas, which are sensitive to nutritional stress. Specifically, we analyzed seven renal carcinoma cell lines. Four of these cell lines produced N-GlcNAc2-modified proteins and led G2/M-phase arrest under glucose deprivation, leading to cell death. The remaining three cell lines did not produce N-GlcNAc2-modified proteins and undergo G1/S-phase arrest under glucose deprivation, leading to survival. The four dead cell lines displayed significant up-regulation in the UDP-GlcNAc biosynthesis pathway as well as increased phosphorylation of p53, which was not observed in the surviving three cell lines. In addition, the four dead cell lines showed prolonged up-regulated expression of ATF3, which is related to unfolded protein response (UPR), while the surviving three cell lines showed only transient up-regulation of ATF3. In this study, we demonstrated that the renal carcinoma cells which accumulate N-GlcNAc2-modified proteins under glucose deprivation do not survive with abnormaly prolonged UPR pathway. By contrast, renal carcinoma cells that do not accumulate N-GlcNAc2-modified proteins under these conditions survive. Morover, we demonstrated that buformin, a UPR inhibitor, efficiently reduced cell survival under conditions of glucose deprivation for both sensitive and resistant phenotypes. Further studies to clarify these findings will lead to the development of novel chemotherapeutic treatments for renal cancer. PMID:24796485

  19. Aloe-emodin induces cell death through S-phase arrest and caspase-dependent pathways in human tongue squamous cancer SCC-4 cells.

    PubMed

    Chiu, Tsan-Hung; Lai, Wan-Wen; Hsia, Te-Chun; Yang, Jai-Sing; Lai, Tung-Yuan; Wu, Ping-Ping; Ma, Chia-Yu; Yeh, Chin-Chung; Ho, Chin-Chin; Lu, Hsu-Feng; Wood, W Gibson; Chung, Jing-Gung

    2009-11-01

    Aloe-emodin, one of the anthraquinones, has been shown to have anticancer activity in different kinds of human cancer cell lines. Therefore, the purpose of this study was to investigate the anti-cancer effect of aloe-emodin on human tongue squamous carcinoma SCC-4 cells. The results indicated that aloe-emodin induced cell death through S-phase arrest and apoptosis in a dose- and time-dependent manner. Treatment with 30 microM of aloe-emodin led to S-phase arrest through promoted p53, p21 and p27, but inhibited cyclin A, E, thymidylate synthase and Cdc25A levels. Aloe-emodin promoted the release of apoptosis-inducing factor (AIF), endonuclease G (Endo G), pro-caspase-9 and cytochrome c from the mitochondria via a loss of the mitochondrial membrane potential (DeltaPsi(m)) which was associated with a increase in the ratio of B-cell lymphoma 2-associated X protein (Bax)/B cell lymphoma/leukemia-2 (Bcl-2) and activation of caspase-9 and -3. The free radical scavenger N-acetylcysteine (NAC) and caspase inhibitors markedly blocked aloe-emodin-induced apoptosis. Aloe-emodin thus induced apoptosis in the SCC-4 cells through the Fas/death-receptor, mitochondria and caspase cascade. Aloe-emodin could be a novel chemotherapeutic drug candidate for the treatment of human tongue squamous cancer in the future.

  20. Methamphetamine Alters the Normal Progression by Inducing Cell Cycle Arrest in Astrocytes

    PubMed Central

    Jackson, Austin R.; Shah, Ankit; Kumar, Anil

    2014-01-01

    Methamphetamine (MA) is a potent psychostimulant with a high addictive capacity, which induces many deleterious effects on the brain. Chronic MA abuse leads to cognitive dysfunction and motor impairment. MA affects many cells in the brain, but the effects on astrocytes of repeated MA exposure is not well understood. In this report, we used Gene chip array to analyze the changes in the gene expression profile of primary human astrocytes treated with MA for 3 days. Range of genes were found to be differentially regulated, with a large number of genes significantly downregulated, including NEK2, TTK, TOP2A, and CCNE2. Gene ontology and pathway analysis showed a highly significant clustering of genes involved in cell cycle progression and DNA replication. Further pathway analysis showed that the genes downregulated by multiple MA treatment were critical for G2/M phase progression and G1/S transition. Cell cycle analysis of SVG astrocytes showed a significant reduction in the percentage of cell in the G2/M phase with a concomitant increase in G1 percentage. This was consistent with the gene array and validation data, which showed that repeated MA treatment downregulated the genes associated with cell cycle regulation. This is a novel finding, which explains the effect of MA treatment on astrocytes and has clear implication in neuroinflammation among the drug abusers. PMID:25290377

  1. 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

  2. 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.

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

    PubMed

    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 100μg/ml, then IL-6 production and expression of apoptosis- and cell cycle progress-related factors were examined. After 24h 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.

  4. 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.

  5. Cell cycle arrest of a Caulobacter crescentus secA mutant.

    PubMed Central

    Kang, P J; Shapiro, L

    1994-01-01

    Cell differentiation is an inherent component of the Caulobacter crescentus cell cycle. The transition of a swarmer cell, with a single polar flagellum, into a sessile stalked cell includes several morphogenetic events. These include the release of the flagellum and pili, the proteolysis of chemotaxis proteins, the biogenesis of the polar stalk, and the initiation of DNA replication. We have isolated a group of temperature-sensitive mutants that are unable to complete this process at the restrictive temperature. We show here that one of these strains has a mutation in a homolog of the Escherichia coli secA gene, whose product is involved in protein translocation at the cell membrane. This C. crescentus secA mutant has allowed the identification of morphogenetic events in the swarmer-to-stalked cell transition that require SecA-dependent protein translocation. Upon shift to the nonpermissive temperature, the mutant secA swarmer cell is able to release the polar flagellum, degrade chemoreceptors, and initiate DNA replication, but it is unable to form a stalk, complete DNA replication, or carry out cell division. At the nonpermissive temperature, the cell cycle blocks prior to the de novo synthesis of flagella and chemotaxis proteins that normally occurs in the predivisional cell. Although interactions between the chromosome and the cytoplasmic membrane are believed to be a functional component of the temporal regulation of DNA replication, the ability of this secA mutant to initiate replication at the nonpermissive temperature suggests that SecA-dependent events are not involved in this process. However, both cell division and stalk formation, which is analogous to a polar division event, require SecA function. Images PMID:8051008

  6. Benzyl isothiocyanate alters the gene expression with cell cycle regulation and cell death in human brain glioblastoma GBM 8401 cells.

    PubMed

    Tang, Nou-Ying; Chueh, Fu-Shin; Yu, Chien-Chih; Liao, Ching-Lung; Lin, Jen-Jyh; Hsia, Te-Chun; Wu, King-Chuen; Liu, Hsin-Chung; Lu, Kung-Wen; Chung, Jing-Gung

    2016-04-01

    Glioblastoma multiforme (GBM) is a highly malignant devastating brain tumor in adults. Benzyl isothiocyanate (BITC) is one of the isothiocyanates that have been shown to induce human cancer cell apoptosis and cell cycle arrest. Herein, the effect of BITC on cell viability and apoptotic cell death and the genetic levels of human brain glioblastoma GBM 8401 cells in vitro were investigated. We found that BITC induced cell morphological changes, decreased cell viability and the induction of cell apoptosis in GBM 8401 cells was time-dependent. cDNA microarray was used to examine the effects of BITC on GBM 8401 cells and we found that numerous genes associated with cell death and cell cycle regulation in GBM 8401 cells were altered after BITC treatment. The results show that expression of 317 genes was upregulated, and two genes were associated with DNA damage, the DNA-damage-inducible transcript 3 (DDIT3) was increased 3.66-fold and the growth arrest and DNA-damage-inducible α (GADD45A) was increased 2.34-fold. We also found that expression of 182 genes was downregulated and two genes were associated with receptor for cell responses to stimuli, the EGF containing fibulin-like extracellular matrix protein 1 (EFEMP1) was inhibited 2.01-fold and the TNF receptor-associated protein 1 (TRAP1) was inhibited 2.08-fold. BITC inhibited seven mitochondria ribosomal genes, the mitochondrial ribosomal protein; tumor protein D52 (MRPS28) was inhibited 2.06-fold, the mitochondria ribosomal protein S2 (MRPS2) decreased 2.07-fold, the mitochondria ribosomal protein L23 (MRPL23) decreased 2.08-fold, the mitochondria ribosomal protein S2 (MRPS2) decreased 2.07-fold, the mitochondria ribosomal protein S12 (MRPS12) decreased 2.08-fold, the mitochondria ribosomal protein L12 (MRPL12) decreased 2.25-fold and the mitochondria ribosomal protein S34 (MRPS34) was decreased 2.30-fold in GBM 8401 cells. These changes of gene expression can provide the effects of BITC on the genetic level and are

  7. Parvovirus B19 NS1 protein induces cell cycle arrest at G2-phase by activating the ATR-CDC25C-CDK1 pathway

    PubMed Central

    Xu, Peng; Zhou, Zhe; Xiong, Min; Zou, Wei; Deng, Xuefeng; Ganaie, Safder S.; Peng, Jianxin; Liu, Kaiyu; Wang, Shengqi; Ye, Shui Qing

    2017-01-01

    Human parvovirus B19 (B19V) infection of primary human erythroid progenitor cells (EPCs) arrests infected cells at both late S-phase and G2-phase, which contain 4N DNA. B19V infection induces a DNA damage response (DDR) that facilitates viral DNA replication but is dispensable for cell cycle arrest at G2-phase; however, a putative C-terminal transactivation domain (TAD2) within NS1 is responsible for G2-phase arrest. To fully understand the mechanism underlying B19V NS1-induced G2-phase arrest, we established two doxycycline-inducible B19V-permissive UT7/Epo-S1 cell lines that express NS1 or NS1mTAD2, and examined the function of the TAD2 domain during G2-phase arrest. The results confirm that the NS1 TAD2 domain plays a pivotal role in NS1-induced G2-phase arrest. Mechanistically, NS1 transactivated cellular gene expression through the TAD2 domain, which was itself responsible for ATR (ataxia-telangiectasia mutated and Rad3-related) activation. Activated ATR phosphorylated CDC25C at serine 216, which in turn inactivated the cyclin B/CDK1 complex without affecting nuclear import of the complex. Importantly, we found that the ATR-CHK1-CDC25C-CDK1 pathway was activated during B19V infection of EPCs, and that ATR activation played an important role in B19V infection-induced G2-phase arrest. PMID:28264028

  8. Shallot and licorice constituent isoliquiritigenin arrests cell cycle progression and induces apoptosis through the induction of ATM/p53 and initiation of the mitochondrial system in human cervical carcinoma HeLa cells.

    PubMed

    Hsu, Ya-Ling; Chia, Chun-Chieh; Chen, Ping-Jye; Huang, Su-Er; Huang, Soon-Cen; Kuo, Po-Lin

    2009-07-01

    This study is the first to investigate the anticancer effect of isoliquiritigenin (ISL) in human cervical carcinoma HeLa cells. The results reveal that ISL inhibits HeLa cells by blocking cell cycle progression in the G2/M phase and inducing apoptosis. Blockade of cell cycle is associated with increased activation of ataxia telangiectasia-mutated (ATM). Activation of ATM by ISL phosphorylated p53 at Serine15, resulting in increased stability of p53 by decreasing p53 and murine double minute-2 (MDM2) interaction. In addition, ISL-mediated G2/M phase arrest was also associated with decreases in the amounts of cyclin B, cyclin A, cdc2, and cdc25C, and increases in the phosphorylation of Chk2, cdc25C, and cdc2. The specific ATM inhibitor caffeine significantly decreased ISL-mediated G2/M arrest by inhibiting the phosphorylation of p53 (Serine15) and Chk2. ISL induced apoptotic cell death is associated with changes in the expression of Bax and Bak, decreasing levels of Bcl-2 and Bcl-X(L), and subsequently triggering mitochondrial apoptotic pathway. In addition, pretreatment of cells with caspase-9 inhibitor blocked ISL-induced apoptosis, indicating that caspase-9 activation is involved in ISL-mediated HeLa cell apoptosis. These findings suggest that ISL may be a promising chemopreventive agent against human uterine cervical cancer.

  9. Antibacterial Activity, in Vitro Cytotoxicity, and Cell Cycle Arrest of Gemini Quaternary Ammonium Surfactants.

    PubMed

    Zhang, Shanshan; Ding, Shiping; Yu, Jing; Chen, Xuerui; Lei, Qunfang; Fang, Wenjun

    2015-11-10

    Twelve gemini quaternary ammonium surfactants have been employed to evaluate the antibacterial activity and in vitro cytotoxicity. The antibacterial effects of the gemini surfactants are performed on Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) with minimum inhibitory concentrations (MIC) ranging from 2.8 to 167.7 μM. Scanning electron microscopy (SEM) analysis results show that these surfactants interact with the bacterial cell membrane, disrupt the integrity of the membrane, and consequently kill the bacteria. The data recorded on C6 glioma and HEK293 human kidney cell lines using an MTT assay exhibit low half inhibitory concentrations (IC50). The influences of the gemini surfactants on the cell morphology, the cell migration ability, and the cell cycle are observed through hematoxylin-eosin (HE) staining, cell wound healing assay, and flow cytometric analyses, respectively. Both the values of MIC and IC50 decrease against the growth of the alkyl chain length of the gemini surfactants with the same spacer group. In the case of surfactants 12-s-12, the MICs and IC50s are found to decrease slightly with the spacer chain length changing from 2 to 8 and again to increase at higher spacer length (s = 10-12). All of the gemini surfactants show great antibacterial activity and cytotoxicity, and they might exhibit potential applications in medical fields.

  10. Cytokinin-mediated cell cycling arrest of pericycle founder cells in lateral root initiation of Arabidopsis.

    PubMed

    Li, Xiang; Mo, Xiaorong; Shou, Huixia; Wu, Ping

    2006-08-01

    In Arabidopsis, lateral root formation is a post-embryonic developmental event, which is regulated by hormones and environmental signals. In this study, via analyzing the expression of cyclin genes during lateral root (LR) formation, we report that cytokinins (CTKs) inhibit the initiation of LR through blocking the pericycle founder cells cycling at the G(2) to M transition phase, while the promotion by CTK of LR elongation is due to the stimulation of the G(1) to S transition. No significant difference was detected in the inhibitory effect of CTK on LR formation between wild-type plants and mutants defective in auxin response or transport. In addition, exogenously applied auxin at different concentrations could not rescue the CTK-mediated inhibition of LR initiation. Our data suggest that CTK and auxin might control LR initiation through two separate signaling pathways in Arabidopsis. The CTK-mediated repression of LR initiation is transmitted through the two-component signal system and mediated by the receptor CRE1.

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

    PubMed

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

    2016-03-01

    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.

  12. 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.

  13. p27kip1 stabilization is essential for the maintenance of cell cycle arrest in response to DNA damage

    PubMed Central

    Cuadrado, Myriam; Gutierrez-Martinez, Paula; Swat, Aneta; Nebreda, Angel R.; Fernandez-Capetillo, Oscar

    2013-01-01

    One of the current models of cancer proposes that oncogenes activate a DNA damage response (DDR), which would limit the growth of the tumor in its earliest stages. In this context, and in contrast to studies focused on the acute responses to a one-time genotoxic insult, understanding how cells respond to a persistent source of DNA damage might become critical for future studies in the field. We here report the discovery of a novel damage-responsive pathway, which involves p27kip1 and retinoblastoma tumour suppressors (TS), and which is only implemented after a persistent exposure to clastogens. In agreement with its late activation, we show that this pathway is critical for the maintenance –but not the initiation- of the cell cycle arrest triggered by DNA damage. Interestingly, this late response is independent of the canonical ATM- and ATR-dependent DDR, but downstream of p38 MAPK. Our results might help to reconcile the oncogene-induced DNA damage model with the clinical evidence that points to non-DDR members as the most important TSs in human cancer. PMID:19843869

  14. Asteraceae Artemisia campestris and Artemisia herba-alba Essential Oils Trigger Apoptosis and Cell Cycle Arrest in Leishmania infantum Promastigotes

    PubMed Central

    Messaoud, Chokri; Haoues, Meriam; Neffati, Noura; Bassoumi Jamoussi, Imen; Essafi-Benkhadir, Khadija; Boussaid, Mohamed; Karoui, Habib

    2016-01-01

    We report the chemical composition and anti-Leishmania and antioxidant activity of Artemisia campestris L. and Artemisia herba-alba Asso. essential oils (EOs). Our results showed that these extracts exhibit different antioxidant activities according to the used assay. The radical scavenging effects determined by DPPH assay were of IC50 = 3.3 mg/mL and IC50 = 9.1 mg/mL for Artemisia campestris and Artemisia herba-alba essential oils, respectively. However, antioxidant effects of both essential oils, determined by ferric-reducing antioxidant power (FRAP) assay, were in the same range (2.3 and 2.97 mg eq EDTA/g EO, resp.), while the Artemisia herba-alba essential oil showed highest chelating activity of Fe2+ ions (27.48 mM Fe2+). Interestingly, we showed that both EOs possess dose-dependent activity against Leishmania infantum promastigotes with IC50 values of 68 μg/mL and 44 μg/mL for A. herba-alba and A. campestris, respectively. We reported, for the first time, that antileishmanial activity of both EOs was mediated by cell apoptosis induction and cell cycle arrest at the sub-G0/G1 phase. All our results showed that EOs from A. herba-alba and A. campestris plants are promising candidates as anti-Leishmania medicinal products. PMID:27807464

  15. 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

  16. Abrogation of MUC5AC Expression Contributes to the Apoptosis and Cell Cycle Arrest of Colon Cancer Cells.

    PubMed

    Zhu, Xijia; Long, Xiangkai; Luo, Xishun; Song, Zhike; Li, Shengguo; Wang, Haipeng

    2016-09-01

    Deregulated expressions of mucins have been found in various malignancies and play a pivotal role in carcinogenesis. MUC5AC, as a secreted mucin, is reported to be aberrantly expressed during epithelial cancer progression, including colon cancer. However, the mechanisms of the oncoprotein MUC5AC in the initiation of colon cancer requires further investigation. Here, we collected colon cancer tissues (n = 20) and corresponding paracancerous tissues (n = 20) and found that the expression of MUC5AC was significantly elevated in colon cancer tissues when compared with the corresponding paracancerous tissues. Immunofluorescence indicated that all colon cancer cell lines, including HT29, SW620, and the normal human intestinal epithelial cells FHC, showed the positive expression of MUC5AC, and SW620 exhibited the highest expression. Moreover, knockdown of MUC5AC in SW620 cells remarkably suppressed cell vitality and promoted apoptosis and G1 cell cycle arrest, resulting in the impaired ability of colony formation. Furthermore, the inhibition of MUC5AC in SW620 cells dramatically repressed the cell migration and invasion. These results demonstrated that MUC5AC as an oncogene could be a promising target in the treatment of colon cancer.

  17. UBE2T silencing suppresses proliferation and induces cell cycle arrest and apoptosis in bladder cancer cells

    PubMed Central

    Gong, Yan Qing; Peng, Ding; Ning, Xiang Hui; Yang, Xin Yu; Li, Xue Song; Zhou, Li Qun; Guo, Ying Lu

    2016-01-01

    Ubiquitin-conjugating enzyme E2T (UBE2T), a member of the ubiquitin-conjugating E2 family in the ubiquitin-proteasome pathway, has been reported to be overexpressed in certain tumor types and to have an important role in the Fanconi anemia pathway. In the present study, the expression of UBE2T and its association with bladder cancer were investigated; to the best of our knowledge, this has not been reported previously. Immunohistochemistry and western blot analysis demonstrated that UBE2T was significantly upregulated in bladder cancer tissues and cell lines compared with adjacent normal bladder tissues and a normal human urinary tract epithelial cell line, respectively. UBE2T was detectable in the nuclei and cytoplasm of cancer cells, exhibiting stronger expression in the nuclei. A UBE2T-siRNA-expressing lentivirus was constructed and used to infect human bladder cancer 5637 cells, in order to examine the role of UBE2T in bladder cancer cell growth in vitro. The knockdown of UBE2T significantly decreased bladder cancer cell proliferation and colony formation. Furthermore, UBE2T silencing induced cell cycle arrest at G2/M phase and increased cell apoptosis. Therefore, UBE2T serves an important role in the growth of bladder cancer cells, and may be considered as a potential biomarker and therapeutic target for bladder cancer. PMID:28101210

  18. 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

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

    PubMed

    Hu, Xuanyu; Guo, Wei; Chen, Shanshan; Xu, Yizhuo; Li, Ping; Wang, Huaqi; Chu, Heying; Li, Juan; DU, Yuwen; Chen, Xiaonan; Zhang, Guojun; Zhao, Guoqiang

    2016-06-01

    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.

  20. 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.

  1. Stromal interaction molecule 1 (STIM1) silencing inhibits tumor growth and promotes cell cycle arrest and apoptosis in hypopharyngeal carcinoma.

    PubMed

    Sun, Yuanhao; Cui, Xiaobo; Wang, Jun; Wu, Shuai; Bai, Yunfei; Wang, Yaping; Wang, Boqian; Fang, Jugao

    2015-05-01

    As an important pathway maintaining the balance of intracellular calcium (Ca(2+)), store-operated Ca(2+) entry (SOCE) is critical for cellular functions. Stromal interaction molecule 1 (STIM1), a key component of SOCE, plays a dual role as an endoplasmic reticulum Ca(2+) receptor and an SOCE exciter. Aberrant expression of STIM1 could be discovered in several human cancer cells. However, the role of STIM1 in regulating human hypopharyngeal carcinoma still remains unclear. Real-time polymerase chain reaction (PCR) was used to detect expression of STIM1 in human hypopharyngeal carcinoma cell line FaDu. STIM1 on FaDu cells was knocked down by lentiviral transduction method. The biological impacts after knocking down of STIM1 on FaDu cells were investigated in vitro and in vivo. The result of real-time PCR showed that STIM1 was expressed in FaDu cells. Lentiviral transduction efficiently downregulated the expression of STIM1 in FaDu cells at both mRNA and protein levels. Significant downregulation of STIM1 on FaDu cells inhibited cell proliferation, induced cell cycle arrest in G0/G1 phase, promoted cell apoptosis, and restrained cell growth rate. The antigrowth effect of STIM1 silencing was also discovered in FaDu hypopharyngeal tumor model. Our findings indicate that STIM1 is likely to become a new therapeutic target for hypopharyngeal carcinoma treatment.

  2. 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

  3. Antioxidant extracts of African medicinal plants induce cell cycle arrest and differentiation in B16F10 melanoma cells.

    PubMed

    Gismondi, Angelo; Canuti, Lorena; Impei, Stefania; Di Marco, Gabriele; Kenzo, Maurice; Colizzi, Vittorio; Canini, Antonella

    2013-09-01

    African ethnomedicine is essentially based on the traditional use of vegetal extracts. Since these natural drugs have shown health giving properties, in the present study we increased further the scientific basis supporting these data. We investigated the effects, on murine B16F10 melanoma cells, of plant extracts that were directly obtained by a Cameroon 'traditional healer'. After a preliminary study on the antioxidant functions of these compounds, already abundant in literature, Moringa oleifera Lam., Eremomastax speciosa (Hochst.) Cufod and Aframomum melegueta K. Schum extracts were individually analyzed. We performed laboratory assessments on these medicinal preparations in order to clearly demonstrate their antineoplastic features. All the treatments caused in tumor cells a great reduction in growth and proliferation rate, cell cycle arrest, increase of p53, p21WAF1/Cip1 and p27Kip1 protein levels and induction of differentiation. These results, on the bioactivity and the biochemical characteristics of African plant extracts, may increase the comprehension of indigenous therapeutic practices and represent the first step for the individuation of new inexpensive and natural drugs able to prevent and contrast cancer onset.

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

    PubMed

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

    2015-10-20

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

  5. Common chronic conditions do not affect performance of cell cycle arrest biomarkers for risk stratification of acute kidney injury

    PubMed Central

    Heung, Michael; Ortega, Luis M.; Chawla, Lakhmir S.; Wunderink, Richard G.; Self, Wesley H.; Koyner, Jay L.; Shi, Jing; Kellum, John A.

    2016-01-01

    Background Identification of acute kidney injury (AKI) can be challenging in patients with underlying chronic disease, and biomarkers often perform poorly in this population. In this study we examined the performance characteristics of the novel biomarker panel of urinary tissue inhibitor of metalloproteinases-2 (TIMP2) and insulin-like growth factor-binding protein 7 ([IGFBP7]) in patients with a variety of comorbid conditions. Methods We analyzed data from two multicenter studies of critically ill patients in which [TIMP2]•[IGFBP7] was validated for prediction of Kidney Disease: Improving Global Outcomes (KDIGO) Stage 2 or 3 AKI within 12 h. We constructed receiver operating characteristic (ROC) curves for AKI prediction both overall and by comorbid conditions common among patients with AKI, including diabetes mellitus, congestive heart failure (CHF) and chronic kidney disease (CKD). Results In the overall cohort of 1131 patients, 139 (12.3%) developed KDIGO Stage 2 or 3 AKI. [TIMP2]•[IGFBP7] was significantly higher in AKI versus non-AKI patients, both overall and within each comorbidity subgroup. The AUC for [TIMP2]•[IGFBP7] in predicting AKI was 0.81 overall. Higher AUC was noted in patients with versus without CHF (0.89 versus 0.79; P = 0.026) and CKD (0.91 versus 0.80; P = 0.024). Conclusions We observed no significant impairment in the performance of cell cycle arrest biomarkers due to the presence of chronic comorbid conditions. PMID:27342582

  6. G1 cell cycle arrest and apoptosis induction by nuclear Smad4/Dpc4: Phenotypes reversed by a tumorigenic mutation

    PubMed Central

    Dai, Jia Le; Bansal, Ravi K.; Kern, Scott E.

    1999-01-01

    The tumor suppressor Smad4/Dpc4 is a transcription activator that binds specific DNA sequences and whose nuclear localization is induced after exposure to type β transforming growth factor-like cytokines. We explored an inducible system in which Smad4 protein is activated by translocation to the nucleus when cell lines that stably express wild-type or mutant Smad4 proteins fused to a murine estrogen receptor domain are treated with 4-hydroxytamoxifen. This induced Smad4-mediated transcriptional activation and a decrease in growth rate, attributable to a cell cycle arrest at the G1 phase and an induction of apoptosis. A tumor-derived mutation (Arg-100 → Thr) affecting a residue critical for DNA-binding demonstrated an “oncogenic” phenotype, having decreases in both the G1 fraction and apoptosis and, consequently, an augmentation of population growth. This model should be useful in the exploration and control of components that lie further downstream in the Smad4 tumor-suppressor pathway. PMID:9990040

  7. Semi-purified extracts of Commelina benghalensis (Commelinaceae) induce apoptosis and cell cycle arrest in Jurkat-T cells

    PubMed Central

    2014-01-01

    Background Commelina benghalensis (CB) is a small plant whose fleshy stems are used in South Africa to treat skin conditions (e.g., cancerous skin outgrowths). This study was aimed at evaluating the effect of sub-fractions of acetone extracts of CB stems on growth-associated molecular events of apoptosis and cell division cycle of Jurkat-T (JT) cells. Methods Acetone extract of CB stems were subfractioned into n-hexane (F1) and dichloromethane (F2) fractions. After treatment of JT cells with these subfractions, cell proliferation, viability and apoptosis were determined using a haemocytometer, the trypan blue dye exclusion assay, and Hoechst 33258 staining, respectively. Cell division cycle distribution profiles were analysed using an Epics Alba Flow Cytometer and the expression of cell division cycle regulatory genes was analysed using RT-PCR, while immunoreactive proteins were detected on western blots. Results The F1 and F2 fractions inhibited the proliferation and viability of JT cells in a concentration- and time-dependent manner, with IC50 values of 32.5 μg/mℓ and 56 μg/mℓ, respectively. The observed cytotoxicity was established to be a consequence of apoptosis. as verified using Hoechst staining method. Both fractions induced a G1/S interphase arrest of the cell division cycle of JT cells. RT-PCR analyses showed an up-regulatory effect by the F1 fraction in the expression of cyclin B1, cdc2 and bax, with a down-regulatory effect in the expression levels of bcl-2. Fraction F1 also increased the protein expression levels of p53 and its downstream regulators, p21 and Cdc2. However, protein Bax and p21 and p53 transcripts were undetectable under the same experimental conditions. On the other hand, fraction F2 increased the mRNA expression levels of bax, bcl-2, cyclin B1 and cdc2. Concomitantly, fraction F2 showed an up-regulation in the protein expression levels of Cdc2, Bcl-2, Cyclin B1 and p21. Despite the up-regulation in protein expression levels by

  8. Cell cycle arrest in cdc20 mutants of Saccharomyces cerevisiae is independent of Ndc10p and kinetochore function but requires a subset of spindle checkpoint genes.

    PubMed Central

    Tavormina, P A; Burke, D J

    1998-01-01

    The spindle checkpoint ensures accurate chromosome segregation by inhibiting anaphase onset in response to altered microtubule function and impaired kinetochore function. In this study, we report that the ability of the anti-microtubule drug nocodazole to inhibit cell cycle progression in Saccharomyces cerevisiae depends on the function of the kinetochore protein encoded by NDC10. We examined the role of the spindle checkpoint in the arrest in cdc20 mutants that arrest prior to anaphase with an aberrant spindle. The arrest in cdc20 defective cells is dependent on the BUB2 checkpoint and independent of the BUB1, BUB3, and MAD spindle checkpoint genes. We show that the lesion recognized by Bub2p is not excess microtubules, and the cdc20 arrest is independent of kinetochore function. We show that Cdc20p is not required for cyclin proteolysis at two points in the cell cycle, suggesting that CDC20 is distinct from genes encoding integral proteins of the anaphase promoting complex. PMID:9560388

  9. 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

  10. The ROS/JNK/ATF2 pathway mediates selenite-induced leukemia NB4 cell cycle arrest and apoptosis in vitro and in vivo.

    PubMed

    An, J J; Shi, K J; Wei, W; Hua, F Y; Ci, Y L; Jiang, Q; Li, F; Wu, P; Hui, K Y; Yang, Y; Xu, C M

    2013-12-19

    It has previously been shown that selenite can act as an antitumor agent and inhibit cancer cell growth, although the mechanism responsible for this effect is not well understood. In this study, we have shown that selenite can induce cell cycle arrest and apoptosis in NB4 cells. Selenite treatment of these cells also inhibited the JNK/ATF2 axis. Further experiments demonstrated that selenite-induced production of reactive oxygen species (ROS) worked as an upstream of the JNK/ATF2 axis, cell cycle arrest and apoptosis. Inactivation of ATF2 resulted in decreased affinity of this transcription factor for the promoters of cyclin A, cyclin D3 and CDK4, which led to the arrest of the NB4 cells in the G0/G1 phase. Finally, in vivo experiments confirmed the antitumor activity of selenite and the mechanisms that were described in vitro. Taken together, our results indicate that selenite-induced ROS arrest NB4 cells at G0/G1 phase through inhibiting the JNK/ATF2 axis in vitro and in vivo.

  11. Cyclin B2 undergoes cell cycle-dependent nuclear translocation and, when expressed as a non-destructible mutant, causes mitotic arrest in HeLa cells

    PubMed Central

    1992-01-01

    Cyclin proteins form complexes with members of the p34cdc2 kinase family and they are essential components of the cell cycle regulatory machinery. They are thought to determine the timing of activation, the subcellular distribution, and/or the substrate specificity of cdc2- related kinases, but their precise mode of action remains to be elucidated. Here we report the cloning and sequencing of avian cyclin B2. Based on the use of monospecific antibodies raised against bacterially expressed protein, we also describe the subcellular distribution of cyclin B2 in chick embryo fibroblasts and in DU249 hepatoma cells. By indirect immunofluorescence microscopy we show that cyclin B2 is cytoplasmic during interphase of the cell cycle, but undergoes an abrupt translocation to the cell nucleus at the onset of mitotic prophase. Finally, we have examined the phenotypic consequences of expressing wild-type and mutated versions of avian cyclin B2 in HeLa cells. We found that expression of cyclin B2 carrying a mutation at arginine 32 (to serine) caused HeLa cells to arrest in a pseudomitotic state. Many of the arrested cells displayed multiple mitotic spindles, suggesting that the centrosome cycle had continued in spite of the cell cycle arrest. PMID:1532584

  12. LW-213 induces G2/M cell cycle arrest through AKT/GSK3β/β-catenin signaling pathway in human breast cancer cells.

    PubMed

    Zhao, Li; Miao, Han-Chi; Li, Wen-Jun; Sun, Yang; Huang, Shao-Liang; Li, Zhi-Yu; Guo, Qing-Long

    2016-05-01

    LW-213 is a derivative of Wogonin and the anticancer activities of Wogonin have been reported. To study whether LW-213 inhibits cancer cells and explore a possible mechanism, we investigate the compound in several cancer cell lines. We found LW-213 arrests G2/M cycle in breast cancer cells by suppression of Akt/Gsk3β/β-catenin signaling pathway. In compound treated cells, cell cycle-related proteins cyclin A, cyclin B1, p-CDK1, p-Cdc25C, and p-Chk2 (Thr68) were upregulated, and β-catenin nuclear translocation was inhibited. Electrophoretic mobility shift assay revealed LW-213 inhibits binding of β-catenin/LEF complex to DNA. GSK3β inhibitor LiCl and siRNA against GSK3β partially reversed G2/M arrest in breast cancer MCF-7 cells. These results suggest LW-213 triggered G2/M cell cycle arrest through suppression of β-catenin signaling. In BALB/c mice, growth of xenotransplanted MCF-7 tumor was also inhibited after treatment of LW-213. Regulation of cyclin A, cyclin B1, and β-catenin by LW-213 in vivo was the same as in vitro study. In conclusion, we found LW-213 exerts its anticancer effect on cell proliferation and cell cycle through repression of Akt/Gsk3β/β-catenin signaling pathway. LW-213 could be a potential candidate for anticancer drug development.

  13. Superoxide dismutase induces G1-phase cell cycle arrest by down-regulated expression of Cdk-2 and cyclin-E in murine sarcoma S180 tumor cells.

    PubMed

    Liu, Dongyue; Liu, Anjun

    2013-06-01

    As an efficient reactive oxygen species-scavenging enzyme, superoxide dismutase (SOD) has been shown to inhibit tumor growth and interfere with motility and invasiveness of cancer cells. In this study, the molecular mechanisms of cell cycle arrest when S180 tumor cells were exposed to high levels of SOD were investigated. Here, both murine sarcoma S180 tumor cells and NIH-3T3 mouse fibroblasts were respectively treated with varying concentrations of Cu/Zn-SOD for 24, 48 and 72 h to determine optimal dose of SOD, which was a concentration of 800 U/ml SOD for 48 h. It is found that SOD induced S180 cell cycle arrest at G1-phase with decreasing level of superoxide production, whereas SOD had less effect on proliferation of NIH-3T3 cells. Moreover, the expression rate of Proliferating Cell Nuclear Antigen (PCNA) in S180 tumor cells was suppressed after SOD treatment, which indicated the inhibition of DNA synthesis in S180 cells. Besides, there were significant down-regulations of cyclin-E and Cdk-2 in S180 cells after SOD treatment, which contributed to the blockage of G1/S transition in S180 cell cycle. Together, our data confirmed that SOD could notably inhibit proliferation of S180 tumor cell and induce cell cycle arrest at G1-phase by down-regulating expressions of cyclin-E and Cdk-2.

  14. Cannabinoid WIN55, 212-2 induces cell cycle arrest and inhibits the proliferation and migration of human BEL7402 hepatocellular carcinoma cells.

    PubMed

    Xu, Dacai; Wang, Jianglin; Zhou, Zhenkang; He, Zhiwei; Zhao, Qing

    2015-12-01

    Hepatocellular carcinoma (HCC) is the leading cause of cancer-associated mortality worldwide; however, only limited therapeutic treatments are currently available. The present study aimed to investigate the effects of cannabinoids as novel therapeutic targets in HCC. In addition, the mechanism underlying the effects of a synthetic cannabinoid, WIN55, 212‑2, on the BEL7402 HCC cell line was investigated. The results demonstrated that WIN55, 212‑2 induced cell cycle arrest of the BEL7402 cells at the G0/G1 phase via cannabinoid receptor 2 (CB2)‑mediated downregulation of phosphorylated-extracellular signal-regulated kinases (ERK)1/2, upregulation of p27, and downregulation of cyclin D1 and cyclin‑dependent kinase 4. Furthermore, inhibition of CB2 with the CB2 antagonist AM630 abrogated WIN55, 212‑2‑induced cell cycle arrest. Inhibition of ERK1/2 also resulted in cell cycle dysregulation and cell cycle arrest at the G0/G1 phase, which subsequently resulted in cell growth inhibition. In addition, the present study detected a significant reduction in matrix metalloproteinase‑9, retinoblastoma protein and E2F1 expression, and migration inhibition by WIN treatment. These results suggested that cannabinoid receptor agonists, including WIN, may be considered as novel therapeutics for the treatment of HCC.

  15. Genistein induces G2/M cell cycle arrest and apoptosis via ATM/p53-dependent pathway in human colon cancer cells.

    PubMed

    Zhang, Zhiyu; Wang, Chong-Zhi; Du, Guang-Jian; Qi, Lian-Wen; Calway, Tyler; He, Tong-Chuan; Du, Wei; Yuan, Chun-Su

    2013-07-01

    Soybean isoflavones have been used as a potential preventive agent in anticancer research for many years. Genistein is one of the most active flavonoids in soybeans. Accumulating evidence suggests that genistein alters a variety of biological processes in estrogen-related malignancies, such as breast and prostate cancers. However, the molecular mechanism of genistein in the prevention of human colon cancer remains unclear. Here we attempted to elucidate the anticarcinogenic mechanism of genistein in human colon cancer cells. First we evaluated the growth inhibitory effect of genistein and two other isoflavones, daidzein and biochanin A, on HCT-116 and SW-480 human colon cancer cells. In addition, flow cyto-metry was performed to observe the morphological changes in HCT-116/SW-480 cells undergoing apoptosis or cell cycle arrest, which had been visualized using Annexin V-FITC and/or propidium iodide staining. Real-time PCR and western blot analyses were also employed to study the changes in expression of several important genes associated with cell cycle regulation. Our data showed that genistein, daidzein and biochanin A exhibited growth inhibitory effects on HCT-116/SW-480 colon cancer cells and promoted apoptosis. Genistein showed a significantly greater effect than the other two compounds, in a time- and dose-dependent manner. In addition, genistein caused cell cycle arrest in the G2/M phase, which was accompanied by activation of ATM/p53, p21waf1/cip1 and GADD45α as well as downregulation of cdc2 and cdc25A demonstrated by q-PCR and immunoblotting assay. Interestingly, genistein induced G2/M cell cycle arrest in a p53-dependent manner. These findings exemplify that isoflavones, especially genistein, could promote colon cancer cell growth inhibition and facilitate apoptosis and cell cycle arrest in the G2/M phase. The ATM/p53-p21 cross-regulatory network may play a crucial role in mediating the anticarcinogenic activities of genistein in colon cancer.

  16. Involvement of the p38 MAPK signaling pathway in S-phase cell-cycle arrest induced by Furazolidone in human hepatoma G2 cells.

    PubMed

    Sun, Yu; Tang, Shusheng; Jin, Xi; Zhang, Chaoming; Zhao, Wenxia; Xiao, Xilong

    2013-12-01

    Given the previously described essential role for the p38 mitogen-activation protein kinase (p38 MAPK) signaling pathway in human hepatoma G2 cells (HepG2), we undertook the present study to investigate the role of the p38 MAPK signaling pathway in cell-cycle arrest induced by Furazolidone (FZD). The aim of this study was to determine the effects of FZD on HepG2 cells by activating and inhibiting the p38 MAPK signaling pathway. The cell cycle and proliferation of HepG2 cells treated with FZD were detected by flow cytometry and MTT assay in the presence or absence of p38 MAPK inhibitors (SB203580), respectively. Cyclin D1, cyclin D3 and CDK6 were detected by quantitative real-time PCR and western blot analysis. Our data showed that p38 MAPK became phosphorylated after stimulation with FZD. Activation of p38 MAPK could arise S-phase cell-cycle arrest and suppress cell proliferation. Simultaneously, inhibition of the p38 MAPK signaling pathway significantly prevented S-phase cell-cycle arrest, increased the percentage of cell viability and decreased the expression of cyclin D1, cyclin D3 and CDK6. These results demonstrated that FZD arose S-phase cell-cycle arrest via activating the p38 MAPK signaling pathway in HepG2 cells. Cyclin D1, cyclin D3 and CDK6 are target genes functioning at the downstream of p38 MAPK in HepG2 cells induced by FZD.

  17. 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).

  18. Effect of radiation on cytotoxicity, apoptosis and cell cycle arrest of human osteosarcoma MG-63 induced by a ruthenium(II) complex.

    PubMed

    Liu, Si-Hong; Zhao, Jian-Hua; Deng, Kun-Kang; Wu, Yong; Zhu, Jian-Wei; Liu, Qing-Hua; Xu, Hui-Hua; Wu, Hai-Feng; Li, Xin-Yan; Wang, Jian-Wei; Guo, Qi-Feng

    2015-04-05

    Radiation has large influence on the cytotoxicity, apoptosis and cell cycle arrest. The bioactivity of ruthenium(II) complex [Ru(dmb)2(DBHIP)](ClO4)2 (Ru1) (DBHIP=2-(3,5-dibromo-4-hydroxylphenyl)imidazo[4,5-f][1,10]phenanthroline) was investigated in the absence and presence of radiation. The cytotoxicity of Ru1 against MG-63 cells was evaluated by CCK-8 method. Ru1 shows high cytotoxicity upon radiation. Radiation can enhance the cytotoxicity of Ru1 on MG-63 cells. The apoptosis was studied by Hoechst 33258 staining method and flow cytometry. The reactive oxygen species, mitochondrial membrane potential, cell cycle arrest and western blot analysis were investigated in detail. The complex induces the apoptosis in MG-63 cells through ROS-mediated mitochondrial dysfunction pathway.

  19. Ectopic cell cycle proteins predict the sites of neuronal cell death in Alzheimer's disease brain.

    PubMed

    Busser, J; Geldmacher, D S; Herrup, K

    1998-04-15

    Alzheimer's disease (AD) is a major dementing illness characterized by regional concentrations of senile plaques, neurofibrillary tangles, and extensive neuronal cell death. Although cell and synaptic loss is most directly linked to the severity of symptoms, the mechanisms leading to the neuronal death remain unclear. Based on evidence linking neuronal death during development to unexpected reappearance of cell cycle events, we investigated the brains of 12 neuropathologically verified cases of Alzheimer's disease and eight age-matched, disease-free controls for the presence of cell cycle proteins. Aberrant expression of cyclin D, cdk4, proliferating cell nuclear antigen, and cyclin B1 were identified in the hippocampus, subiculum, locus coeruleus, and dorsal raphe nuclei, but not inferotemporal cortex or cerebellum of AD cases. With only one exception, control subjects showed no significant expression of cell cycle markers in any of the six regions. We propose that disregulation of various components of the cell cycle is a significant contributor to regionally specific neuronal death in AD.

  20. 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

  1. MicroRNA-101 targets von Hippel-Lindau tumor suppressor (VHL) to induce HIF1α mediated apoptosis and cell cycle arrest in normoxia condition

    PubMed Central

    Liu, Ning; Xia, Wu-Yan; Liu, Shan-Shan; Chen, Hai-Yan; Sun, Lei; Liu, Meng-Yao; Li, Lin-Feng; Lu, Hong-Min; Fu, Yu-Jie; Wang, Pei; Wu, Hailong; Gao, Jian-Xin

    2016-01-01

    The activation/inactivation of HIF1α is precisely regulated in an oxygen-dependent manner. HIF1α is essential for hypoxia induced apoptosis and cell cycle arrest. Several recent studies indicated that the expression of miRNAs can be modulated by hypoxia. However, the involvement of miRNAs in the regulation of HIF1α induction remains elusive. In present study, we demonstrated that miR-101 was rapidly and transiently induced after hypoxia in breast cancer cells. Over-expression of miR-101 significantly inhibited cell proliferation in breast cancer cells through increased apoptosis and cell cycle arrest in normoxia condition. This inhibitory phenomenon seems due to miR-101-mediated induction of HIF1α, because we identified that VHL, a negative regulator of HIF1α, is a novel target of miR-101 and over-expression of miR-101 decreased VHL levels and subsequently stabilized HIF1α and induced its downstream target VEGFA. Furthermore, we demonstrated that siRNA-mediated knockdown of VHL or HIF1α overexpression could also induce apoptosis and cell cycle arrest whereas enforced expression of VHL, administration of anti-miR-101 oligos or treatment of 2-MeOE2, an inhibitor of HIF1α, could rescue cells from such inhibition. These results reveal a novel regulatory mechanism of HIF1α induction in normoxia and suggest that miR-101 mediated proliferation inhibition may through HIF1α mediated apoptosis and cell cycle arrest. PMID:26841847

  2. MicroRNA-101 targets von Hippel-Lindau tumor suppressor (VHL) to induce HIF1α mediated apoptosis and cell cycle arrest in normoxia condition.

    PubMed

    Liu, Ning; Xia, Wu-Yan; Liu, Shan-Shan; Chen, Hai-Yan; Sun, Lei; Liu, Meng-Yao; Li, Lin-Feng; Lu, Hong-Min; Fu, Yu-Jie; Wang, Pei; Wu, Hailong; Gao, Jian-Xin

    2016-02-04

    The activation/inactivation of HIF1α is precisely regulated in an oxygen-dependent manner. HIF1α is essential for hypoxia induced apoptosis and cell cycle arrest. Several recent studies indicated that the expression of miRNAs can be modulated by hypoxia. However, the involvement of miRNAs in the regulation of HIF1α induction remains elusive. In present study, we demonstrated that miR-101 was rapidly and transiently induced after hypoxia in breast cancer cells. Over-expression of miR-101 significantly inhibited cell proliferation in breast cancer cells through increased apoptosis and cell cycle arrest in normoxia condition. This inhibitory phenomenon seems due to miR-101-mediated induction of HIF1α, because we identified that VHL, a negative regulator of HIF1α, is a novel target of miR-101 and over-expression of miR-101 decreased VHL levels and subsequently stabilized HIF1α and induced its downstream target VEGFA. Furthermore, we demonstrated that siRNA-mediated knockdown of VHL or HIF1α overexpression could also induce apoptosis and cell cycle arrest whereas enforced expression of VHL, administration of anti-miR-101 oligos or treatment of 2-MeOE2, an inhibitor of HIF1α, could rescue cells from such inhibition. These results reveal a novel regulatory mechanism of HIF1α induction in normoxia and suggest that miR-101 mediated proliferation inhibition may through HIF1α mediated apoptosis and cell cycle arrest.

  3. c-Jun NH(2)-terminal kinase signaling axis regulates diallyl trisulfide-induced generation of reactive oxygen species and cell cycle arrest in human prostate cancer cells.

    PubMed

    Antosiewicz, Jedrzej; Herman-Antosiewicz, Anna; Marynowski, Stanley W; Singh, Shivendra V

    2006-05-15

    We have shown previously that generation of reactive oxygen species (ROS) is a critical event in G(2)-M phase cell cycle arrest caused by diallyl trisulfide (DATS), which is a highly promising anticancer constituent of processed garlic. Using DU145 and PC-3 human prostate cancer cells as a model, we now report a novel mechanism involving c-Jun NH(2)-terminal kinase (JNK) signaling axis, which is known for its role in regulation of cell survival and apoptosis, in DATS-induced ROS production. The DATS-induced ROS generation, G(2)-M phase cell cycle arrest and degradation, and hyperphosphorylation of Cdc25C were significantly attenuated in the presence of EUK134, a combined mimetic of superoxide dismutase and catalase. Interestingly, the DATS-induced ROS generation and G(2)-M phase cell cycle arrest were also inhibited significantly in the presence of desferrioxamine, an iron chelator, but this protection was not observed with iron-saturated desferrioxamine. DATS treatment caused a marked increase in the level of labile iron that was accompanied by degradation of light chain of iron storage protein ferritin. Interestingly, DATS-mediated degradation of ferritin, increase in labile iron pool, ROS generation, and/or cell cycle arrest were significantly attenuated by ectopic expression of a catalytically inactive mutant of JNK kinase 2 and RNA interference of stress-activated protein kinase/extracellular signal-regulated kinase 1 (SEK1), upstream kinases in JNK signal transduction pathway. In conclusion, the present study provides experimental evidence to indicate existence of a novel pathway involving JNK signaling axis in regulation of DATS-induced ROS generation.

  4. Cytotoxicity, cell cycle arrest, and apoptosis in breast cancer cell lines exposed to an extract of the seed kernel of Mangifera pajang (bambangan).

    PubMed

    Abu Bakar, Mohd Fadzelly; Mohamad, Maryati; Rahmat, Asmah; Burr, Steven A; Fry, Jeffrey R

    2010-06-01

    An extract of Mangifera pajang kernel has been previously found to contain a high content of antioxidant phytochemicals. The present research was conducted to investigate the anticancer potential of this kernel extract. The results showed that the kernel crude extract induced cytotoxicity in MCF-7 (hormone-dependent breast cancer) cells and MDA-MB-231 (non-hormone dependent breast cancer) cells with IC50 values of 23 and 30.5 microg/ml, respectively. The kernel extract induced cell cycle arrest in MCF-7 cells at the sub-G1 (apoptosis) phase of the cell cycle in a time-dependent manner. For MDA-MB-231 cells, the kernel extract induced strong G2-M arrest in cell cycle progression at 24h, resulting in substantial sub-G1 (apoptosis) arrest after 48 and 72 h of incubation. Staining with Annexin V-FITC and propidium iodide revealed that this apoptosis occurred early in both cell types, 36 h for MCF-7 cells and 24 h for MDA-MB-231 cells, with 14.0% and 16.5% of the cells respectively undergoing apoptosis at these times. This apoptosis appeared to be dependent on caspase-2 and -3 in MCF-7 cells, and on caspase-2, -3 and -9 in MDA-MB-231 cells. These findings suggest that M. pajang kernel extract has potential as a potent cytotoxic agent against breast cancer cell lines.

  5. Cell cycle arrest induced by inhibitors of epigenetic modifications in maize (Zea mays) seedling leaves: characterization of the process and possible mechanisms involved.

    PubMed

    Wang, Pu; Zhang, Hao; Hou, Haoli; Wang, Qing; Li, Yingnan; Huang, Yan; Xie, Liangfu; Gao, Fei; He, Shibin; Li, Lijia

    2016-07-01

    Epigenetic modifications play crucial roles in the regulation of chromatin architecture and are involved in cell cycle progression, including mitosis and meiosis. To explore the relationship between epigenetic modifications and the cell cycle, we treated maize (Zea mays) seedlings with six different epigenetic modification-related inhibitors and identified the postsynthetic phase (G2 ) arrest via flow cytometry analysis. Total H4K5ac levels were significantly increased and the distribution of H3S10ph signalling was obviously changed in mitosis under various treatments. Further statistics of the cells in different periods of mitosis confirmed that the cell cycle was arrested at preprophase. Concentrations of hydrogen peroxide were relatively higher in the treated plants and the antioxidant thiourea could negate the influence of the inhibitors. Moreover, all of the treated plants displayed negative results in the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labelling (TUNEL) and γ-H2AX immunostaining assays after exposure for 3 d. Additionally, the expression level of topoisomerase genes in the treated plants was relatively lower than that in the untreated plants. These results suggest that these inhibitors of epigenetic modifications could cause preprophase arrest via reactive oxygen species formation inhibiting the expression of DNA topoisomerase genes, accompanied by changes in the H4K5ac and H3S10ph histone modifications.

  6. Notch1 signaling inhibits growth of human hepatocellular carcinoma through induction of cell cycle arrest and apoptosis.

    PubMed

    Qi, Runzi; An, Huazhang; Yu, Yizhi; Zhang, Minghui; Liu, Shuxun; Xu, Hongmei; Guo, Zhenghong; Cheng, Tao; Cao, Xuetao

    2003-12-01

    Notch signaling plays a critical role in maintaining the balance between cell proliferation, differentiation, and apoptosis; hence, perturbed Notch signaling may contribute to tumorigenesis. Hepatocellular carcinoma (HCC) is one of the most common malignant tumors in Africa and Asia. The mechanisms that orchestrate the multiple oncogenic insults required for initiation and progression of HCC are not clear. We constitutively overexpressed active Notch1 in human HCC to explore the effects of Notch1 signaling on HCC cell growth and to investigate the underlying molecular mechanisms. We show here that overexpression of Notch1 was able to inhibit the growth of HCC cells in vitro and in vivo. Biochemical analysis revealed the involvement of cell cycle regulated proteins in Notch1-mediated G(0)/G(1) arrest of HCC cells. Compared with green fluorescent protein (GFP) control, transient transfection of Notch1 ICN decreased expression of cyclin A (3.5-fold), cyclin D1 (2-fold), cyclin E (4.5-fold), CDK2 (2.8-fold), and the phosphorylated form of retinoblastoma protein (3-fold). Up-regulation of p21(waf/cip1) protein expression was observed in SMMC7721-ICN cells stably expressing active Notch1 but not in SMMC7721-GFP cells, which only express GFP. Furthermore, a 12-fold increase in p53 expression and an increase (4.8-fold) in Jun-NH(2)-terminal kinase activation were induced in SMMC7721-ICN cells compared with SMMC7721-GFP cells. In contrast, expression of the antiapoptotic Bcl-2 protein could not be detected in SMMC7721-ICN cells. These findings suggest that Notch1 signaling may participate in the development of HCC cells, affecting multiple pathways that control both cell proliferation and apoptosis.

  7. A novel curcumin derivative which inhibits P-glycoprotein, arrests cell cycle and induces apoptosis in multidrug resistance cells.

    PubMed

    Lopes-Rodrigues, Vanessa; Oliveira, Ana; Correia-da-Silva, Marta; Pinto, Madalena; Lima, Raquel T; Sousa, Emília; Vasconcelos, M Helena

    2017-01-15

    Cancer multidrug resistance (MDR) is a major limitation to the success of cancer treatment and is highly associated with the overexpression of drug efflux pumps such as P-glycoprotein (P-gp). In order to achieve more effective chemotherapeutic treatments, it is important to develop P-gp inhibitors to block/decrease its activity. Curcumin (1) is a secondary metabolite isolated from the turmeric of Curcuma longa L.. Diverse biological activities have been identified for this compound, particularly, MDR modulation in various cancer cell models. However, curcumin (1) has low chemical stability, which severely limits its application. In order to improve stability and P-gp inhibitory effect, two potential more stable curcumin derivatives were synthesized as building blocks, followed by several curcumin derivatives. These compounds were then analyzed in terms of antitumor and anti-P-gp activity, in two MDR and sensitive tumor lines (from chronic myeloid leukemia and non-small cell lung cancer). We identified from a series of curcumin derivatives a novel curcumin derivative (1,7-bis(3-methoxy-4-(prop-2-yn-1-yloxy)phenyl)hepta-1,6-diene-3,5-dione, 10) with more potent antitumor and anti-P-gp activity than curcumin (1). This compound (10) was shown to promote cell cycle arrest (at the G2/M phase) and induce apoptosis in the MDR chronic myeloid leukemia cell line. Therefore it is a really interesting P-gp inhibitor due to its ability to inhibit both P-gp function and expression.

  8. Arctigenin, a natural lignan compound, induces G0/G1 cell cycle arrest and apoptosis in human glioma cells

    PubMed Central

    Maimaitili, Aisha; Shu, Zunhua; Cheng, Xiaojiang; Kaheerman, Kadeer; Sikandeer, Alifu; Li, Weimin

    2017-01-01

    The aim of the current study was to investigate the anticancer potential of arctigenin, a natural lignan compound, in malignant gliomas. The U87MG and T98G human glioma cell lines were treated with various concentrations of arctigenin for 48 h and the effects of arctigenin on the aggressive phenotypes of glioma cells were assessed. The results demonstrated that arctigenin dose-dependently inhibited the growth of U87MG and T98G cells, as determined using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and bromodeoxyuridine incorporation assays. Arctigenin exposure also induced a 60–75% reduction in colony formation compared with vehicle-treated control cells. However, arctigenin was not observed to affect the invasiveness of glioma cells. Arctigenin significantly increased the proportion of cells in the G0/G1 phase and reduced the number of cells in the S phase, as compared with the control group (P<0.05). Western blot analysis demonstrated that arctigenin increased the expression levels of p21, retinoblastoma and p53 proteins, and significantly decreased the expression levels of cyclin D1 and cyclin-dependent kinase 4 proteins. Additionally, arctigenin was able to induce apoptosis in glioma cells, coupled with increased expression levels of cleaved caspase-3 and the pro-apoptotic BCL2-associated X protein. Furthermore, arctigenin-induced apoptosis was significantly suppressed by the pretreatment of cells with Z-DEVD-FMK, a caspase-3 inhibitor. In conclusion, the results suggest that arctigenin is able to inhibit cell proliferation and may induce apoptosis and cell cycle arrest at the G0/G1 phase in glioma cells. These results warrant further investigation of the anticancer effects of arctigenin in animal models of gliomas. PMID:28356992

  9. 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.

  10. Arctigenin, a natural lignan compound, induces G0/G1 cell cycle arrest and apoptosis in human glioma cells.

    PubMed

    Maimaitili, Aisha; Shu, Zunhua; Cheng, Xiaojiang; Kaheerman, Kadeer; Sikandeer, Alifu; Li, Weimin

    2017-02-01

    The aim of the current study was to investigate the anticancer potential of arctigenin, a natural lignan compound, in malignant gliomas. The U87MG and T98G human glioma cell lines were treated with various concentrations of arctigenin for 48 h and the effects of arctigenin on the aggressive phenotypes of glioma cells were assessed. The results demonstrated that arctigenin dose-dependently inhibited the growth of U87MG and T98G cells, as determined using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and bromodeoxyuridine incorporation assays. Arctigenin exposure also induced a 60-75% reduction in colony formation compared with vehicle-treated control cells. However, arctigenin was not observed to affect the invasiveness of glioma cells. Arctigenin significantly increased the proportion of cells in the G0/G1 phase and reduced the number of cells in the S phase, as compared with the control group (P<0.05). Western blot analysis demonstrated that arctigenin increased the expression levels of p21, retinoblastoma and p53 proteins, and significantly decreased the expression levels of cyclin D1 and cyclin-dependent kinase 4 proteins. Additionally, arctigenin was able to induce apoptosis in glioma cells, coupled with increased expression levels of cleaved caspase-3 and the pro-apoptotic BCL2-associated X protein. Furthermore, arctigenin-induced apoptosis was significantly suppressed by the pretreatment of cells with Z-DEVD-FMK, a caspase-3 inhibitor. In conclusion, the results suggest that arctigenin is able to inhibit cell proliferation and may induce apoptosis and cell cycle arrest at the G0/G1 phase in glioma cells. These results warrant further investigation of the anticancer effects of arctigenin in animal models of gliomas.

  11. Green Synthesis of Silver and Titanium Dioxide Nanoparticles Using Euphorbia prostrata Extract Shows Shift from Apoptosis to G0/G1 Arrest followed by Necrotic Cell Death in Leishmania donovani

    PubMed Central

    Zahir, Abdul Abduz; Chauhan, Indira Singh; Bagavan, Asokan; Kamaraj, Chinnaperumal; Elango, Gandhi; Shankar, Jai; Arjaria, Nidhi; Roopan, Selvaraj Mohana

    2015-01-01

    The aim of the present study was to synthesize silver (Ag) and titanium dioxide (TiO2) nanoparticles (NPs) using green synthesis from aqueous leaf extract of Euphorbia prostrata as antileishmanial agents and to explore the underlying molecular mechanism of induced cell death. In vitro antileishmanial activity of synthesized NPs was tested against promastigotes of Leishmania donovani by alamarBlue and propidium iodide uptake assays. Antileishmanial activity of synthesized NPs on intracellular amastigotes was assessed by Giemsa staining. The leishmanicidal effect of synthesized Ag NPs was further confirmed by DNA fragmentation assay and by cell cycle progression and transmission electron microscopy (TEM) of the treated parasites. TEM analysis of the synthesized Ag NPs showed a spherical shape with an average size of 12.82 ± 2.50 nm, and in comparison to synthesized TiO2 NPs, synthesized Ag NPs were found to be most active against Leishmania parasites after 24 h exposure, with 50% inhibitory concentrations (IC50) of 14.94 μg/ml and 3.89 μg/ml in promastigotes and intracellular amastigotes, respectively. A significant increase in G0/G1 phase of the cell cycle with a subsequent decrease in S (synthesis) and G2/M phases compared to controls was observed. The growth-inhibitory effect of synthesized Ag NPs was attributed to increased length of S phase. A decreased reactive oxygen species level was also observed, which could be responsible for the caspase-independent shift from apoptosis (G0/G1 arrest) to massive necrosis. High-molecular-weight DNA fragmentation as a positive consequence of necrotic cell death was also visualized. We also report that the unique trypanothione/trypanothione reductase (TR) system of Leishmania cells was significantly inhibited by synthesized Ag NPs. The green-synthesized Ag NPs may provide promising leads for the development of cost-effective and safer alternative treatment against visceral leishmaniasis. PMID:26033724

  12. Green Synthesis of Silver and Titanium Dioxide Nanoparticles Using Euphorbia prostrata Extract Shows Shift from Apoptosis to G0/G1 Arrest followed by Necrotic Cell Death in Leishmania donovani.

    PubMed

    Zahir, Abdul Abduz; Chauhan, Indira Singh; Bagavan, Asokan; Kamaraj, Chinnaperumal; Elango, Gandhi; Shankar, Jai; Arjaria, Nidhi; Roopan, Selvaraj Mohana; Rahuman, Abdul Abdul; Singh, Neeloo

    2015-08-01

    The aim of the present study was to synthesize silver (Ag) and titanium dioxide (TiO2) nanoparticles (NPs) using green synthesis from aqueous leaf extract of Euphorbia prostrata as antileishmanial agents and to explore the underlying molecular mechanism of induced cell death. In vitro antileishmanial activity of synthesized NPs was tested against promastigotes of Leishmania donovani by alamarBlue and propidium iodide uptake assays. Antileishmanial activity of synthesized NPs on intracellular amastigotes was assessed by Giemsa staining. The leishmanicidal effect of synthesized Ag NPs was further confirmed by DNA fragmentation assay and by cell cycle progression and transmission electron microscopy (TEM) of the treated parasites. TEM analysis of the synthesized Ag NPs showed a spherical shape with an average size of 12.82 ± 2.50 nm, and in comparison to synthesized TiO2 NPs, synthesized Ag NPs were found to be most active against Leishmania parasites after 24 h exposure, with 50% inhibitory concentrations (IC50) of 14.94 μg/ml and 3.89 μg/ml in promastigotes and intracellular amastigotes, respectively. A significant increase in G0/G1 phase of the cell cycle with a subsequent decrease in S (synthesis) and G2/M phases compared to controls was observed. The growth-inhibitory effect of synthesized Ag NPs was attributed to increased length of S phase. A decreased reactive oxygen species level was also observed, which could be responsible for the caspase-independent shift from apoptosis (G0/G1 arrest) to massive necrosis. High-molecular-weight DNA fragmentation as a positive consequence of necrotic cell death was also visualized. We also report that the unique trypanothione/trypanothione reductase (TR) system of Leishmania cells was significantly inhibited by synthesized Ag NPs. The green-synthesized Ag NPs may provide promising leads for the development of cost-effective and safer alternative treatment against visceral leishmaniasis.

  13. Polydatin, a natural precursor of resveratrol, induces cell cycle arrest and differentiation of human colorectal Caco-2 cell

    PubMed Central

    2013-01-01

    Background Human colon adenocarcinoma cells are resistant to chemotherapeutic agents, such as anthracyclines, that induce death by increasing the reactive oxygen species. A number of studies have been focused on chemo-preventive use of resveratrol as antioxidant against cardiovascular diseases, aging and cancer. While resveratrol cytotoxic action was due to its pro-oxidant properties. In this study, we investigate whether the Resveratrol (trans-3,5,49-trihydroxystilbene) and its natural precursor Polydatin (resveratrol-3-O-b-mono- D-glucoside, the glycoside form of resveratrol) combination, might have a cooperative antitumor effect on either growing or differentiated human adenocarcinoma colon cancer cells. Methods The polydatin and resveratrol pharmacological interaction was evaluated in vitro on growing and differentiated Caco-2 cell lines by median drug effect analysis calculating a combination index with CalcuSyn software. We have selected a synergistic combination and we have evaluated its effect on the biological and molecular mechanisms of cell death. Results Simultaneous exposure to polydatin and resveratrol produced synergistic antiproliferative effects compared with single compound treatment. We demonstrated that polydatin alone or in combination with resveratrol at 3:1 molar ratio synergistically modulated oxidative stress, cell cycle, differentiation and apoptosis. Worthy of note treatment with polydatin induced a nuclear localization and decreased expression of heat shock protein 27, and vimentin redistributed within the cell. Conclusions From morphological, and biochemical outcome we obtained evidences that polydatin induced a transition from a proliferative morphology to cell-specific differentiated structures and caused human CaCo-2 cell death by induction of apoptosis. Our data suggest the potential use of polydatin in combination chemotherapy for human colon cancer. PMID:24138806

  14. Inducing the cell cycle arrest and apoptosis of oral KB carcinoma cells by hydroxychavicol: roles of glutathione and reactive oxygen species

    PubMed Central

    Chang, M C; Uang, B J; Wu, H L; Lee, J J; Hahn, L J; Jeng, J H

    2002-01-01

    Hydroxychavicol (HC; 10 – 50 μM), a betel leaf component, was found to suppress the 2% H2O2-induced lucigenin chemiluminescence for 53 – 75%. HC (0.02 – 2 μM) was also able to trap superoxide radicals generated by a xanthine/xanthine oxidase system with 38 – 94% of inhibition. Hydroxyl radicals-induced PUC18 plasmid DNA breaks was prevented by HC (1.6 – 16 μM).A 24-h exposure of KB cells to HC (0.5, 1 mM) resulted in 54 – 74% cell death as analysed by a 3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) assay. HC (10, 50 μM) further suppressed the growth of KB cells (15 and 76%, respectively). Long-term colony formation of KB cells was inhibited by 51% with 10 μM HC.Pretreatment of KB cells with 100 μM HC inhibited the attachment of KB cells to type I collagen and fibronectin by 59 and 29%, respectively.Exposure of KB cells to 0.1 mM HC for 24 h resulted in cell cycle arrest at late S and G2/M phase. Increasing the HC concentration to 0.25 and 0.5 mM led to apoptosis as revealed by detection of sub-G0/G1 peaks with a concomitant decrease in the number of cells residing in late S and G2/M phase.Inducing the apoptosis of KB cells by HC was accompanied by marked depletion in reduced form of GSH (>0.2 mM) and the increasing of reactive oxygen species production (>0.1 mM) as analysed by CMF- and DCF-single cell fluorescence flow cytometry.These results indicate that HC exerts antioxidant property at low concentration. HC also inhibits the growth, adhesion and cell cycle progression of KB cells, whereas its induction of KB cell apoptosis (HC>0.1 mM) was accompanied by cellular redox changes. PMID:11834609

  15. Adenovirus E4orf4 protein-induced death of p53-/- H1299 human cancer cells follows a G1 arrest of both tetraploid and diploid cells due to a failure to initiate DNA synthesis.

    PubMed

    Cabon, Lauriane; Sriskandarajah, Neera; Mui, Melissa Z; Teodoro, Jose G; Blanchette, Paola; Branton, Philip E

    2013-12-01

    The adenovirus E4orf4 protein selectively kills human cancer cells independently of p53 and thus represents a potentially promising tool for the development of novel antitumor therapies. Previous studies suggested that E4orf4 induces an arrest or a delay in mitosis and that both this effect and subsequent cell death rely largely on an interaction with the B55 regulatory subunit of protein phosphatase 2A. In the present report, we show that the death of human H1299 lung carcinoma cells induced by expression of E4orf4 is typified not by an accumulation of cells arrested in mitosis but rather by the presence of both tetraploid and diploid cells that are arrested in G1 because they are unable to initiate DNA synthesis. We believe that these E4orf4-expressing cells eventually die by various processes, including those resulting from mitotic catastrophe.

  16. Genetic inactivation of Cdk7 leads to cell cycle arrest and induces premature aging due to adult stem cell exhaustion

    PubMed Central

    Ganuza, Miguel; Sáiz-Ladera, Cristina; Cañamero, Marta; Gómez, Gonzalo; Schneider, Ralph; Blasco, María A; Pisano, David; Paramio, Jesús M; Santamaría, David; Barbacid, Mariano

    2012-01-01

    Cyclin-dependent kinase (Cdk)7, the catalytic subunit of the Cdk-activating kinase (CAK) complex has been implicated in the control of cell cycle progression and of RNA polymerase II (RNA pol II)-mediated transcription. Genetic inactivation of the Cdk7 locus revealed that whereas Cdk7 is completely dispensable for global transcription, is essential for the cell cycle via phosphorylation of Cdk1 and Cdk2. In vivo, Cdk7 is also indispensable for cell proliferation except during the initial stages of embryonic development. Interestingly, widespread elimination of Cdk7 in adult tissues with low proliferative indexes had no phenotypic consequences. However, ablation of conditional Cdk7 alleles in tissues with elevated cellular turnover led to the efficient repopulation of these tissues with Cdk7-expressing cells most likely derived from adult stem cells that may have escaped the inactivation of their targeted Cdk7 alleles. This process, a physiological attempt to maintain tissue homeostasis, led to the attrition of adult stem cell pools and to the appearance of age-related phenotypes, including telomere shortening and early death. PMID:22505032

  17. G2/M cell cycle arrest on HT-29 cancer cells and toxicity assessment of triphenylphosphanegold(I) carbonimidothioates, Ph3PAu[SC(OR)=NPh], R=Me, Et, and iPr, during zebrafish development.

    PubMed

    Ooi, Kah Kooi; Yeo, Chien Ing; Mahandaran, Theventhiran; Ang, Kok Pian; Akim, Abdah Md; Cheah, Yoke-Kqueen; Seng, Hoi-Ling; Tiekink, Edward R T

    2017-01-01

    Phosphanegold(I) thiolates, Ph3PAu[SC(OR)=NPh], R=Me (1), Et (2) and iPr (3), were previously shown to be significantly cytotoxic toward HT-29 cancer cells and to induce cell death by both intrinsic and extrinsic apoptotic pathways whereby 1 activated the p73 gene, and each of 2 and 3 activated p53; 2 also caused apoptotic cell death via the c-Jun N-terminal kinase/mitogen-activated protein kinase pathway. Apoptosis pathways have been further evaluated by mitochondrial cytochrome c measurements and annexin V screening, confirming apoptotic pathways of cell death. Cell cycle analysis showed the majority of treated HT-29 cells were arrested at the G2/M checkpoint after 24h; results of both assays were confirmed by changes in populations of relevant genes (PCR array analysis). Cell invasion studies showed inhibition of metastasis through Matrigel™ matrix to 17-22% cf. untreated cells. LC50 values were determined in zebrafish (8.36, 8.17, and 7.64μM for 1-3). Finally, the zebrafish tolerated doses of 1 and 2 up to 0.625μM, and 3 was tolerated at even higher doses of up to 1.25μM.

  18. Resistance for Genotoxic Damage in Mesenchymal Stromal Cells Is Increased by Hypoxia but Not Generally Dependent on p53-Regulated Cell Cycle Arrest

    PubMed Central

    Wieduwild, Elisabeth; Nerger, Katrin; Lambrecht, Nina; Schmoll, Hans-Joachim; Müller-Tidow, Carsten; Müller, Lutz Peter

    2017-01-01

    Adult stem cells including multipotent mesenchymal stromal cells (MSC) acquire a high amount of DNA-damage due to their prolonged lifespan. MSC may exert specific mechanisms of resistance to avoid loss of functional activity. We have previously shown that resistance of MSC is associated with an induction of p53 and proliferation arrest upon genotoxic damage. Hypoxia may also contribute to resistance in MSC due to the low oxygen tension in the niche. In this study we characterized the role of p53 and contribution of hypoxia in resistance of MSC to genotoxic damage. MSC exhibited increased resistance to cisplatin induced DNA-damage. This resistance was associated with a temporary G2/M cell cycle arrest, induction of p53- and p21-expression and reduced cyclin B / cdk1-levels upon subapoptotic damage. Resistance of MSC to cisplatin was increased at hypoxic conditions i. e. oxygen <0.5%. However, upon hypoxia the cisplatin-induced cell cycle arrest and expression of p53 and p21 were abrogated. MSC with shRNA-mediated p53 knock-down showed a reduced cell cycle arrest and increased cyclin B / cdk1 expression. However, this functional p53 knock down did not alter the resistance to cisplatin. In contrast to cisplatin, functional p53-knock-down increased the resistance of MSC to etoposide. We conclude that resistance of MSC to genotoxic damage is influenced by oxygen tension but is not generally dependent on p53. Thus, p53-dependent and p53-independent mechanisms of resistance are likely to contribute to the life-long functional activity of MSC in vivo. These findings indicate that hypoxia and different resistance pathways contribute to the phenotype that enables the prolonged lifespan of MSC. PMID:28081228

  19. Human immunodeficiency virus type 1 viral protein R (Vpr) arrests cells in the G2 phase of the cell cycle by inhibiting p34cdc2 activity.

    PubMed Central

    He, J; Choe, S; Walker, R; Di Marzio, P; Morgan, D O; Landau, N R

    1995-01-01

    The Vpr accessory gene product of human immunodeficiency virus types 1 and 2 and simian immunodeficiency virus is believed to play a role in permitting entry of the viral core into the nucleus of nondividing cells. A second role for Vpr was recently suggested by Rogel et al. (M. E. Rogel, L. I. Wu, and M. Emerman, J. Virol. 69:882-888, 1995), who showed that Vpr prevents the establishment in vitro of chronically infected HIV producer cell lines, apparently by causing infected cells to arrest in the G2/M phase of the cell cycle. In cycling cells, progression from G2 to M phase is driven by activation of the p34cdc2/cyclin B complex, an event caused, in part, by dephosphorylation of two regulatory amino acids of p34cdc2 (Thr-14 and Tyr-15). We show here that Vpr arrests the cell cycle in G2 by preventing the activation of the p34cdc2/cyclin B complex. Vpr expression in cells caused p34cdc2 to remain in the phosphorylated, inactive state, p34cdc2/cyclin B complexes immunoprecipitated from cells expressing Vpr were almost completely inactive in a histone H1 kinase assay. Coexpression of a constitutively active mutant p34cdc2 molecule with Vpr relieved the G2 arrest. These findings strongly suggest that Vpr arrests cells in G2 by preventing the activation of the p34cdc2/cyclin B complex that is required for entry into M phase. In vivo, Vpr might, by preventing p34cdc2 activation, delay or prevent apoptosis of infected cells. This would increase the amount of virus each infected cell produced. PMID:7474080

  20. 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.

  1. 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.

  2. Co-existence of periodic bursts and death of cycles in a population dynamics system

    NASA Astrophysics Data System (ADS)

    Iyengar, Sudharsana V.; Balakrishnan, Janaki; Kurths, Jürgen

    2016-09-01

    We study the dynamics of a discrete-time tritrophic model which mimics the observed periodicity in the population cycles of the larch budmoth insect which causes widespread defoliation of larch forests at high altitudes periodically. Our model employs q-deformation of numbers to model the system comprising the budmoth, one or more parasitoid species, and larch trees. Incorporating climate parameters, we introduce additional parasitoid species and show that their introduction increases the periodicity of the budmoth cycles as observed experimentally. The presence of these additional species also produces other interesting dynamical effects such as periodic bursting and oscillation quenching via oscillation death, amplitude death, and partial oscillation death which are also seen in nature. We suggest that introducing additional parasitoid species provides an alternative explanation for the collapse of the nine year budmoth outbreak cycles observed in the Swiss Alps after 1981. A detailed exploration of the parameter space of the system is performed with movies of bifurcation diagrams which enable variation of two parameters at a time. Limit cycles emerge through a Neimark-Sacker bifurcation with respect to all parameters in all the five and higher dimensional models we have studied.

  3. Demethylation and alterations in the expression level of the cell cycle-related genes as possible mechanisms in arsenic trioxide-induced cell cycle arrest in human breast cancer cells.

    PubMed

    Moghaddaskho, Farima; Eyvani, Haniyeh; Ghadami, Mohsen; Tavakkoly-Bazzaz, Javad; Alimoghaddam, Kamran; Ghavamzadeh, Ardeshir; Ghaffari, Seyed H

    2017-02-01

    Arsenic trioxide (As2O3) has been used clinically as an anti-tumor agent. Its mechanisms are mostly considered to be the induction of apoptosis and cell cycle arrest. However, the detailed molecular mechanisms of its anti-cancer action through cell cycle arrest are poorly known. Furthermore, As2O3 has been shown to be a potential DNA methylation inhibitor, inducing DNA hypomethylation. We hypothesize that As2O3 may affect the expression of cell cycle regulatory genes by interfering with DNA methylation patterns. To explore this, we examined promoter methylation status of 24 cell cycle genes in breast cancer cell lines and in a normal breast tissue sample by methylation-specific polymerase chain reaction and/or restriction enzyme-based methods. Gene expression level and cell cycle distribution were quantified by real-time polymerase chain reaction and flow cytometric analyses, respectively. Our methylation analysis indicates that only promoters of RBL1 (p107), RASSF1A, and cyclin D2 were aberrantly methylated in studied breast cancer cell lines. As2O3 induced CpG island demethylation in promoter regions of these genes and restores their expression correlated with DNA methyltransferase inhibition. As2O3 also induced alterations in messenger RNA expression of several cell cycle-related genes independent of demethylation. Flow cytometric analysis revealed that the cell cycle arrest induced by As2O3 varied depending on cell lines, MCF-7 at G1 phase and both MDA-MB-231 and MDA-MB-468 cells at G2/M phase. These changes at transcriptional level of the cell cycle genes by the molecular mechanisms dependent and independent of demethylation are likely to represent the mechanisms of cell cycle redistribution in breast cancer cells, in response to As2O3 treatment.

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

    NASA Astrophysics Data System (ADS)

    Kim, Joomi

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

  5. Induction of G1 Cell Cycle Arrest in Human Glioma Cells by Salinomycin Through Triggering ROS-Mediated DNA Damage In Vitro and In Vivo.

    PubMed

    Zhao, Shi-Jun; Wang, Xian-Jun; Wu, Qing-Jian; Liu, Chao; Li, Da-Wei; Fu, Xiao-Ting; Zhang, Hui-Fang; Shao, Lu-Rong; Sun, Jing-Yi; Sun, Bao-Liang; Zhai, Jing; Fan, Cun-Dong

    2016-12-19

    Chemotherapy has always been one of the most effective ways in combating human glioma. However, the high metastatic potential and resistance toward standard chemotherapy severely hindered the chemotherapy outcomes. Hence, searching effective chemotherapy drugs and clarifying its mechanism are of great significance. Salinomycin an antibiotic shows novel anticancer potential against several human tumors, including human glioma, but its mechanism against human glioma cells has not been fully elucidated. In the present study, we demonstrated that salinomycin treatment time- and dose-dependently inhibited U251 and U87 cells growth. Mechanically, salinomycin-induced cell growth inhibition against human glioma was mainly achieved by induction of G1-phase arrest via triggering reactive oxide species (ROS)-mediated DNA damage, as convinced by the activation of histone, p53, p21 and p27. Furthermore, inhibition of ROS accumulation effectively attenuated salinomycin-induced DNA damage and G1 cell cycle arrest, and eventually reversed salinomycin-induced cytotoxicity. Importantly, salinomycin treatment also significantly inhibited the U251 tumor xenograft growth in vivo through triggering DNA damage-mediated cell cycle arrest with involvement of inhibiting cell proliferation and angiogenesis. The results above validated the potential of salinomycin-based chemotherapy against human glioma.

  6. Physangulidine A, a withanolide from Physalis angulata, perturbs the cell cycle and induces cell death by apoptosis in prostate cancer cells.

    PubMed

    Reyes-Reyes, E Merit; Jin, Zhuang; Vaisberg, Abraham J; Hammond, Gerald B; Bates, Paula J

    2013-01-25

    Recently, our group reported the discovery of three new withanolides, physangulidines A-C, from Physalis angulata. In this study, the biological effects of physangulidine A (1), which was the most active and abundant of the three new constituents, are described. It was found that 1 significantly reduces survival in clonogenic assays for two hormone-independent prostate cancer cell lines. Flow cytometry and confocal microscopy studies in DU145 human prostate cancer cells indicated that 1 induces cell cycle arrest in the G(2)/M phase and causes defective mitosis. It was determined also that 1 produces programed cell death by apoptosis, as evidenced by biochemical markers and distinct changes in cell morphology. These results imply that the antimitotic and proapoptotic effects of 1 may contribute significantly to the biological activities and potential medicinal properties of its plant of origin.

  7. Andrographis paniculata extracts and major constituent diterpenoids inhibit growth of intrahepatic cholangiocarcinoma cells by inducing cell cycle arrest and apoptosis.

    PubMed

    Suriyo, Tawit; Pholphana, Nanthanit; Rangkadilok, Nuchanart; Thiantanawat, Apinya; Watcharasit, Piyajit; Satayavivad, Jutamaad

    2014-05-01

    Andrographis paniculata is an important herbal medicine widely used in several Asian countries for the treatment of various diseases due to its broad range of pharmacological activities. The present study reports that A. paniculata extracts potently inhibit the growth of liver (HepG2 and SK-Hep1) and bile duct (HuCCA-1 and RMCCA-1) cancer cells. A. paniculata extracts with different contents of major diterpenoids, including andrographolide, 14-deoxy-11,12-didehydroandrographolide, neoandrographolide, and 14-deoxyandrographolide, exhibited a different potency of growth inhibition. The ethanolic extract of A. paniculata at the first true leaf stage, which contained a high amount of 14-deoxyandrographolide but a low amount of andrographolide, showed a cytotoxic effect to cancer cells about 4 times higher than the water extract of A. paniculata at the mature leaf stage, which contained a high amount of andrographolide but a low amount of 14-deoxyandrographolide. Andrographolide, not 14-deoxy-11,12-didehydroandrographolide, neoandrographolide, or 14-deoxyandrographolide, possessed potent cytotoxic activity against the growth of liver and bile duct cancer cells. The cytotoxic effect of the water extract of A. paniculata at the mature leaf stage could be explained by the present amount of andrographolide, while the cytotoxic effect of the ethanolic extract of A. paniculata at the first true leaf stage could not. HuCCA-1 cells showed more sensitivity to A. paniculata extracts and andrographolide than RMCCA-1 cells. Furthermore, the ethanolic extract of A. paniculata at the first true leaf stage increased cell cycle arrest at the G0/G1 and G2/M phases, and induced apoptosis in both HuCCA-1 and RMCCA-1 cells. The expressions of cyclin-D1, Bcl-2, and the inactive proenzyme form of caspase-3 were reduced by the ethanolic extract of A. paniculata in the first true leaf stage treatment, while a proapoptotic protein Bax was increased. The cleavage of poly (ADP

  8. Crude extract and solvent fractions of Calystegia soldanella induce G1 and S phase arrest of the cell cycle in HepG2 cells

    PubMed Central

    Lee, Jung Im; Kim, In-Hye; Nam, Taek-Jeong

    2017-01-01

    The representative halophyte Calystegia soldanella (L) Roem. et Schult is a perennial vine herb that grows in coastal dunes throughout South Korea as well as in other regions around the world. This plant has long been used as an edible and medicinal herb to cure rheumatic arthritis, sore throat, dropsy, and scurvy. Some studies have also shown that this plant species exhibits various biological activities. However, there are few studies on cytotoxicity induced by C. soldanella treatment in HepG2 human hepatocellular carcinoma cells. In this study, we investigated the viability of HepG2 cells following treatment with crude extracts and four solvent-partitioned fractions of C. soldanella. Of the crude extract and four solvent fractions tested, treatment with the 85% aqueous methanol (aq. MeOH) fraction resulted in the greatest inhibition of HepG2 cell proliferation. Flow cytometry showed that the 85% aq. MeOH fraction induced a G0/G1 and S phase arrest of the cell cycle progression. The 85% aq. MeOH fraction arrested HepG2 cells at the G0/G1 phase in a concentration-dependent manner, and resulted in decreased expression of cyclin D1, cyclin E, cyclin-dependent kinase (CDK)2, CDK4, CDK6, p21, and p27. Additionally, the 85% aq. MeOH fraction treatment also arrested HepG2 cells in the S phase, with decreased expression of cyclin A, CDK2, and CDC25A. Also, treatment with this fraction reduced the expression of retinoblastoma (RB) protein and the transcription factor E2F. These results suggest that the 85% aq. MeOH fraction exhibits potential anticancer activity in HepG2 cells by inducing G0/G1 and S phase arrest of the cell cycle. PMID:28101580

  9. 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

  10. Disrupted cell cycle arrest and reduced proliferation in corneal fibroblasts from GCD2 patients: A potential role for altered autophagy flux

    SciTech Connect

    Choi, Seung-il; Dadakhujaev, Shorafidinkhuja; Maeng, Yong-Sun; Ahn, So-yeon; Kim, Tae-im; Kim, Eung Kweon

    2015-01-02

    Highlights: • Reduced cell proliferation in granular corneal dystrophy type 2. • Abnormal cell cycle arrest by defective autophagy. • Decreased Cyclin A1, B1, and D1 in Atg7 gene knockout cells. • Increase in p16 and p27 expressions were observed in Atg7 gene knockout cells. - Abstract: This study investigates the role of impaired proliferation, altered cell cycle arrest, and defective autophagy flux of corneal fibroblasts in granular corneal dystrophy type 2 (GCD2) pathogenesis. The proliferation rates of homozygous (HO) GCD2 corneal fibroblasts at 72 h, 96 h, and 120 h were significantly lower (1.102 ± 0.027, 1.397 ± 0.039, and 1.527 ± 0.056, respectively) than those observed for the wild-type (WT) controls (1.441 ± 0.029, 1.758 ± 0.043, and 2.003 ± 0.046, respectively). Flow cytometry indicated a decreased G{sub 1} cell cycle progression and the accumulation of cells in the S and G{sub 2}/M phases in GCD2 cells. These accumulations were associated with decreased levels of Cyclin A1, B1, and E1, and increased expression of p16 and p27. p21 and p53 expression was also significantly lower in GCD2 cells compared to the WT. Interestingly, treatment with the autophagy flux inhibitor, bafilomycin A{sub 1}, resulted in similarly decreased Cyclin A1, B1, D1, and p53 expression in WT fibroblasts. Furthermore, similar findings, including a decrease in Cyclin A1, B1, and D1 and an increase in p16 and p27 expression were observed in autophagy-related 7 (Atg7; known to be essential for autophagy) gene knockout cells. These data provide new insight concerning the role of autophagy in cell cycle arrest and cellular proliferation, uncovering a number of novel therapeutic possibilities for GCD2 treatment.

  11. Sodium ascorbate inhibits growth via the induction of cell cycle arrest and apoptosis in human malignant melanoma A375.S2 cells.

    PubMed

    Lin, Shuw-Yuan; Lai, Wan-Wen; Chou, Chi-Chung; Kuo, Hsiu-Maan; Li, Te-Mao; Chung, Jing-Gung; Yang, Jen-Hung

    2006-12-01

    Vitamin C has been reported to be useful in the treatment and prevention of cancer. Inconsistent effects from growth stimulation to induction of apoptosis of malignant tumor cells, however, have been reported. Melanoma is an increasingly common and potentially lethal malignancy. It was reported that melanoma cells were more susceptible to ascorbate toxicity than any other tumor cells. The mechanisms accounting for ascorbate-induced apoptosis in human melanoma cells, however, have remained unclear. This study was undertaken to investigate the effect of sodium ascorbate on cytotoxicity and apoptosis in human malignant melanoma A375.S2 cells. A375.S2 cells were incubated with a certain range of concentrations of sodium ascorbate for various time periods. In order to examine the effects of sodium ascorbate on cell proliferation, cell cycle, apoptosis and necrosis, we performed 4,6-diamidino-2-phenylindole dihydrochloride assays and flow cytometry analysis. Polymerase chain reaction was used to examine the mRNA levels of p53, p21, p27, cyclin A, cyclin E, CDK2 and CDK4, which are associated with cell cycle S-phase arrest and apoptosis. Flow cytometric analysis showed that sodium ascorbate significantly induced cell cycle arrest and apoptosis in the A375.S2 cell line in a dose-dependent manner. The increased expressions of p53 and p21, and the decreased expressions of cyclin A, cyclin E, CDK2 and CDK4, indicated the cell cycle arrest at G1/S phase after the cells had been treated with sodium ascorbate. Induction of apoptosis involved an increase in the levels of p53, p21 and cellular Ca, and a decrease in mitochondrial membrane potential and activation of caspase 3 before culminating in apoptosis in sodium ascorbate-treated A375.S2 cells.

  12. Evidence of an Epigenetic Modification in Cell-cycle Arrest Caused by the Use of Ultra-highly-diluted Gonolobus Condurango Extract

    PubMed Central

    Bishayee, Kausik; Sikdar, Sourav; Khuda-Bukhsh, Anisur Rahman

    2013-01-01

    Objectives: Whether the ultra-highly-diluted remedies used in homeopathy can effectively bring about modulations of gene expressions through acetylation/deacetylation of histones has not been explored. Therefore, in this study, we pointedly checked if the homeopathically-diluted anti-cancer remedy Condurango 30C (ethanolic extract of Gonolobus condurango diluted 10-60 times) was capable of arresting the cell cycles in cervical cancer cells HeLa by triggering an epigenetic modification through modulation of the activity of the key enzyme histone deacetylase 2 vis-a-vis the succussed alcohol (placebo) control. Methods: We checked the activity of different signal proteins (like p21WAF, p53, Akt, STAT3) related to deacetylation, cell growth and differentiation by western blotting and analyzed cell-cycle arrest, if any, by fluorescence activated cell sorting. After viability assays had been performed with Condurango 30C and with a placebo, the activities of histone de-acetylase (HDAC) enzymes 1 and 2 were measured colorimetrically. Results: While Condurango 30C induced cytotoxicity in HeLa cells in vitro and reduced HDAC2 activity quite strikingly, it apparently did not alter the HDAC1 enzyme; the placebo had no or negligible cytotoxicity against HeLa cells and could not alter either the HDAC 1 or 2 activity. Data on p21WAF, p53, Akt, and STAT3 activities and a cell-cycle analysis revealed a reduction in DNA synthesis and G1-phase cell-cycle arrest when Condurango 30C was used at a 2% dose. Conclusion: Condurango 30C appeared to trigger key epigenetic events of gene modulation in effectively combating cancer cells, which the placebo was unable to do. PMID:25780677

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

    PubMed

    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.

  14. Cucurbitacin D induces cell cycle arrest and apoptosis by inhibiting STAT3 and NF-κB signaling in doxorubicin-resistant human breast carcinoma (MCF7/ADR) cells.

    PubMed

    Ku, Jin Mo; Kim, Soon Re; Hong, Se Hyang; Choi, Han-Seok; Seo, Hye Sook; Shin, Yong Cheol; Ko, Seong-Gyu

    2015-11-01

    Breast cancer is the most common cancer for women and is a major cause of mortality in women. Doxorubicin is a generally used chemotherapy drug for breast cancer. However, multidrug resistance of breast cancer interferes with the chemotherapy. We examined whether cucurbitacin D affects doxorubicin resistance of MCF7/ADR breast cancer cells. Cell viability was measured by MTT assay. Levels of p-STAT3, p-NF-κB, IκB, and caspases were measured by Western blot analysis. Nuclear staining of Stat3 and NF-κB was measured by immunocytochemistry. STAT3 and NF-κB transcriptional activity was detected by STAT3 and NF-κB luciferase reporter gene assays. Analysis of cell cycle arrest was performed by flow cytometry. Induction of apoptosis by cucurbitacin D was measured by Annexin V-FITC/propidium iodide assay. More than 90% of MCF7/ADR cells lived upon treatment with doxorubicin for 24 h. However, upon treatment with cucurbitacin D, cell death was more than 60%. Co-administration of cucurbitacin D and doxorubicin induced apoptosis, and G2/M cell cycle arrest, and inhibited upregulated Stat3 by doxorubicin on MCF7/ADR cells. Additionally, cucurbitacin D led to an increase in the IκBα level in the cytosol and a decrease in the p-NF-κB level in the nucleus. Finally, cucurbitacin D inhibited translocation of Stat3 and NF-κB and decreased transcriptional activity in the nucleus. Cucurbitacin D decreases cell proliferation and induces apoptosis by inhibiting Stat3 and NF-κB signaling in doxorubicin-resistant breast cancer cells. Cucurbitacin D could be used as a useful compound to treat adriamycin-resistant patients.

  15. Gatifloxacin induces S and G2-phase cell cycle arrest in pancreatic cancer cells via p21/p27/p53.

    PubMed

    Yadav, Vikas; Sultana, Sarwat; Yadav, Jyoti; Saini, Neeru

    2012-01-01

    Pancreatic cancer, despite being the most dreadful among gastrointestinal cancers, is poorly diagnosed, and further, the situation has been aggravated owing to acquired drug resistance against the single known drug therapy. While previous studies have highlighted the growth inhibitory effects of older generation fluoroquinolones, the current study aims to evaluate the growth inhibitory effects of newer generation fluoroquinolone, Gatifloxacin, on pancreatic cancer cell lines MIA PaCa-2 and Panc-1 as well as to elucidate the underlying molecular mechanisms. Herein, we report that Gatifloxacin suppresses the proliferation of MIA PaCa-2 and Panc-1 cells by causing S and G(2)-phase cell cycle arrest without induction of apoptosis. Blockade in S-phase of the cell cycle was associated with increased TGF-β1 expression and translocation of Smad3-4 complex to the nucleus with subsequent activation of p21 in MIA PaCa-2 cells, whereas TGF-β signalling attenuated Panc-1 cells showed S-phase arrest by direct activation of p27. However, Gatifloxacin mediated G(2)-phase cell cycle arrest was found to be p53 dependent in both the cell lines. Our study is of interest because fluoroquinolones have the ability to penetrate pancreatic tissue which can be very effective in combating pancreatic cancers that are usually associated with loss or downregulation of CDK inhibitors p21/p27 as well as mutational inactivation of p53. Additionally, Gatifloxacin was also found to synergize the effect of Gemcitabine, the only known drug against pancreatic cancer, as well as the broad spectrum anticancer drug cisplatin. Taken together our results suggest that Gatifloxacin possesses anticancer activities against pancreatic cancer and is a promising candidate to be repositioned from broad spectrum antibiotics to anticancer agent.

  16. Docosahexaenoic acid-induced unfolded protein response, cell cycle arrest, and apoptosis in vascular smooth muscle cells are triggered by Ca2+-dependent induction of oxidative stress

    PubMed Central

    Crnkovic, Slaven; Riederer, Monika; Lechleitner, Margarete; Hallström, Seth; Malli, Roland; Graier, Wolfgang F.; Lindenmann, Jörg; Popper, Helmut; Olschewski, Horst; Olschewski, Andrea; Frank, Saša

    2012-01-01

    Proliferation of vascular smooth muscle cells is a characteristic of pathological vascular remodeling and represents a significant therapeutic challenge in several cardiovascular diseases. Docosahexaenoic acid (DHA), a member of the n-3 polyunsaturated fatty acids, was shown to inhibit proliferation of numerous cell types, implicating several different mechanisms. In this study we examined the molecular events underlying the inhibitory effects of DHA on proliferation of primary human smooth muscle cells isolated from small pulmonary artery (hPASMCs). DHA concentration-dependently inhibited hPASMC proliferation, induced G1 cell cycle arrest, and decreased cyclin D1 protein expression. DHA activated the unfolded protein response (UPR), evidenced by increased mRNA expression of HSPA5, increased phosphorylation of eukaryotic initiation factor 2α, and splicing of X-box binding protein 1. DHA altered cellular lipid composition and led to increased reactive oxygen species (ROS) production. DHA-induced ROS were dependent on both intracellular Ca2+ release and entry of extracellular Ca2+. Overall cellular ROS and mitochondrial ROS were decreased by RU360, a specific inhibitor of mitochondrial Ca2+ uptake. DHA-induced mitochondrial dysfunction was evidenced by decreased mitochondrial membrane potential and decreased cellular ATP content. DHA triggered apoptosis as found by increased numbers of cleaved caspase-3- and TUNEL-positive cells. The free radical scavenger Tempol counteracted DHA-induced ROS, cell cycle arrest, induction of UPR, and apoptosis. We conclude that Ca2+-dependent oxidative stress is the central and initial event responsible for induction of UPR, cell cycle arrest, and apoptosis in DHA-treated hPASMCs. PMID:22391221

  17. 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.

  18. DNA hypomethylation induces a DNA replication-associated cell cycle arrest to block hepatic outgrowth in uhrf1 mutant zebrafish embryos.

    PubMed

    Jacob, Vinitha; Chernyavskaya, Yelena; Chen, Xintong; Tan, Poh Seng; Kent, Brandon; Hoshida, Yujin; Sadler, Kirsten C

    2015-02-01

    UHRF1 (ubiquitin-like, containing PHD and RING finger domains, 1) recruits DNMT1 to hemimethylated DNA during replication and is essential for maintaining DNA methylation. uhrf1 mutant zebrafish have global DNA hypomethylation and display embryonic defects, including a small liver, and they die as larvae. We make the surprising finding that, despite their reduced organ size, uhrf1 mutants express high levels of genes controlling S-phase and have many more cells undergoing DNA replication, as measured by BrdU incorporation. In contrast to wild-type hepatocytes, which are continually dividing during hepatic outgrowth and thus dilute the BrdU label, uhrf1 mutant hepatocytes retain BrdU throughout outgrowth, reflecting cell cycle arrest. Pulse-chase-pulse experiments with BrdU and EdU, and DNA content analysis indicate that uhrf1 mutant cells undergo DNA re-replication and that apoptosis is the fate of many of the re-replicating and arrested hepatocytes. Importantly, the DNA re-replication phenotype and hepatic outgrowth failure are preceded by global loss of DNA methylation. Moreover, uhrf1 mutants are phenocopied by mutation of dnmt1, and Dnmt1 knockdown in uhrf1 mutants enhances their small liver phenotype. Together, these data indicate that unscheduled DNA replication and failed cell cycle progression leading to apoptosis are the mechanisms by which DNA hypomethylation prevents organ expansion in uhrf1 mutants. We propose that cell cycle arrest leading to apoptosis is a strategy that restricts propagation of epigenetically damaged cells during embryogenesis.

  19. Cell cycle modulation by Marek's disease virus: the tegument protein VP22 triggers S-phase arrest and DNA damage in proliferating cells.

    PubMed

    Trapp-Fragnet, Laëtitia; Bencherit, Djihad; Chabanne-Vautherot, Danièle; Le Vern, Yves; Remy, Sylvie; Boutet-Robinet, Elisa; Mirey, Gladys; Vautherot, Jean-François; Denesvre, Caroline

    2014-01-01

    Marek's disease is one of the most common viral diseases of poultry affecting chicken flocks worldwide. The disease is caused by an alphaherpesvirus, the Marek's disease virus (MDV), and is characterized by the rapid onset of multifocal aggressive T-cell lymphoma in the chicken host. Although several viral oncogenes have been identified, the detailed mechanisms underlying MDV-induced lymphomagenesis are still poorly understood. Many viruses modulate cell cycle progression to enhance their replication and persistence in the host cell, in the case of some oncogenic viruses ultimately leading to cellular transformation and oncogenesis. In the present study, we found that MDV, like other viruses, is able to subvert the cell cycle progression by triggering the proliferation of low proliferating chicken cells and a subsequent delay of the cell cycle progression into S-phase. We further identified the tegument protein VP22 (pUL49) as a major MDV-encoded cell cycle regulator, as its vector-driven overexpression in cells lead to a dramatic cell cycle arrest in S-phase. This striking functional feature of VP22 appears to depend on its ability to associate with histones in the nucleus. Finally, we established that VP22 expression triggers the induction of massive and severe DNA damages in cells, which might cause the observed intra S-phase arrest. Taken together, our results provide the first evidence for a hitherto unknown function of the VP22 tegument protein in herpesviral reprogramming of the cell cycle of the host cell and its potential implication in the generation of DNA damages.

  20. Cell Cycle Modulation by Marek’s Disease Virus: The Tegument Protein VP22 Triggers S-Phase Arrest and DNA Damage in Proliferating Cells

    PubMed Central

    Trapp-Fragnet, Laëtitia; Bencherit, Djihad; Chabanne-Vautherot, Danièle; Le Vern, Yves; Remy, Sylvie; Boutet-Robinet, Elisa; Mirey, Gladys; Vautherot, Jean-François; Denesvre, Caroline

    2014-01-01

    Marek’s disease is one of the most common viral diseases of poultry affecting chicken flocks worldwide. The disease is caused by an alphaherpesvirus, the Marek’s disease virus (MDV), and is characterized by the rapid onset of multifocal aggressive T-cell lymphoma in the chicken host. Although several viral oncogenes have been identified, the detailed mechanisms underlying MDV-induced lymphomagenesis are still poorly understood. Many viruses modulate cell cycle progression to enhance their replication and persistence in the host cell, in the case of some oncogenic viruses ultimately leading to cellular transformation and oncogenesis. In the present study, we found that MDV, like other viruses, is able to subvert the cell cycle progression by triggering the proliferation of low proliferating chicken cells and a subsequent delay of the cell cycle progression into S-phase. We further identified the tegument protein VP22 (pUL49) as a major MDV-encoded cell cycle regulator, as its vector-driven overexpression in cells lead to a dramatic cell cycle arrest in S-phase. This striking functional feature of VP22 appears to depend on its ability to associate with histones in the nucleus. Finally, we established that VP22 expression triggers the induction of massive and severe DNA damages in cells, which might cause the observed intra S-phase arrest. Taken together, our results provide the first evidence for a hitherto unknown function of the VP22 tegument protein in herpesviral reprogramming of the cell cycle of the host cell and its potential implication in the generation of DNA damages. PMID:24945933

  1. Umbilical Cord Tissue-Derived Mesenchymal Stem Cells Induce T Lymphocyte Apoptosis and Cell Cycle Arrest by Expression of Indoleamine 2, 3-Dioxygenase

    PubMed Central

    Li, Xiuying; Xu, Zhuo; Bai, Jinping; Yang, Shuyuan; Zhao, Shuli; Zhang, Yingjie; Chen, Xiaodong

    2016-01-01

    It has been reported that human mesenchymal stem cells are able to inhibit T lymphocyte activation; however, the discrepancy among different sources of MSCs is not well documented. In this study, we have compared the MSCs from bone marrow (BM), adipose tissue (AT), placenta (PL), and umbilical cord (UC) to determine which one displayed the most efficient immunosuppressive effects on phytohemagglutinin-induced T cell proliferation. Among them we found that hUC-MSC has the strongest effects on inhibiting T cell proliferation and is chosen to do the further study. We observed that T lymphocyte spontaneously released abundant IFN-γ. And IFN-γ secreted by T lymphocyte could induce the expression of indoleamine 2, 3-dioxygenase (IDO) in hUC-MSCs. IDO was previously reported to induce T lymphocyte apoptosis and cell cycle arrest in S phase. When cocultured with hUC-MSCs, T lymphocyte expression of caspase 3 was significantly increased, while Bcl2 and CDK4 mRNA expression decreased dramatically. Addition of 1-methyl tryptophan (1-MT), an IDO inhibitor, restored T lymphocyte proliferation, reduced apoptosis, and induced resumption of the cell cycle. In addition, the changes in caspase 3, CDK4, and Bcl2 expression were reversed by 1-MT. These findings demonstrate that hUC-MSCs induce T lymphocyte apoptosis and cell cycle arrest by expressing abundant IDO and provide an explanation for some of the immunomodulatory effects of MSCs. PMID:27418932

  2. Costunolide and dehydrocostuslactone combination treatment inhibit breast cancer by inducing cell cycle arrest and apoptosis through c-Myc/p53 and AKT/14-3-3 pathway.

    PubMed

    Peng, Zhangxiao; Wang, Yan; Fan, Jianhui; Lin, Xuejing; Liu, Chunying; Xu, Yang; Ji, Weidan; Yan, Chao; Su, Changqing

    2017-01-24

    Our previous studies demonstrated that volatile oil from saussurea lappa root (VOSL), rich in two natural sesquiterpene lactones, costunolide (Cos) and dehydrocostuslactone (Dehy), exerts better anti-breast cancer efficacy and lower side effects than Cos or Dehy alone in vivo, however, their anti-cancer molecular mechanisms were still unknown. In this study, we investigated the underlying mechanisms of Cos and Dehy combination treatment (CD) on breast cancer cells through proteomics technology coupled with Western blot validation. Ingenuity Pathways Analysis (IPA) results based on the differentially expressed proteins revealed that both VOSL and CD affect the 14-3-3-mediated signaling, c-Myc mediated apoptosis signaling and protein kinase A (PKA) signaling. Western blot coupled with cell cycle and apoptosis analysis validated the results of proteomics analysis. Cell cycle arrest and apoptosis were induced in a dose-dependent manner, and the expressions of p53 and p-14-3-3 were significantly up-regulated, whereas the expressions of c-Myc, p-AKT, p-BID were significantly down-regulated, furthermore, the ratio of BAX/BCL-2 were significantly increased in breast cancer cells after CD and VOSL treatment. The findings indicated that VOSL and CD could induce breast cancer cell cycle arrest and apoptosis through c-Myc/p53 and AKT/14-3-3 signaling pathways and may be novel effective candidates for breast cancer treatment.

  3. The MicroRNA 424/503 Cluster Reduces CDC25A Expression during Cell Cycle Arrest Imposed by Transforming Growth Factor β in Mammary Epithelial Cells

    PubMed Central

    Rodriguez-Barrueco, Ruth; de la Iglesia-Vicente, Janis; Olivan, Mireia; Castro, Veronica; Saucedo-Cuevas, Laura; Marshall, Netonia; Putcha, Preeti; Castillo-Martin, Mireia; Bardot, Evan; Ezhkova, Elena; Iavarone, Antonio; Cordon-Cardo, Carlos

    2014-01-01

    Recently, we demonstrated that the microRNA 424(322)/503 [miR-424(322)/503] cluster is transcriptionally controlled by transforming growth factor β (TGF-β) in the mammary epithelium. Induction of this microRNA cluster impacts mammary epithelium fate by regulating apoptosis and insulin-like growth factor 1 (IGF1) signaling. Here, we expanded our finding to demonstrate that miR-424(322)/503 is an integral component of the cell cycle arrest mediated by TGF-β. Mechanistically, we showed that after TGF-β exposure, increased levels of miR-424(322)/503 reduce the expression of the cell cycle regulator CDC25A. miR-424(322)/503-dependent posttranscriptional downregulation of CDC25A cooperates with previously described transcriptional repression of the CDC25A promoter and proteasome-mediated degradation to reduce the levels of CDC25A expression and to induce cell cycle arrest. We also provide evidence that the TGF-β/miR-424(322)/503 axis is part of the mechanism that regulates the proliferation of hormone receptor-positive (HR+) mammary epithelial cells in vivo. PMID:25266660

  4. Antitumor Activity of Tenacissoside H on Esophageal Cancer through Arresting Cell Cycle and Regulating PI3K/Akt-NF-κB Transduction Cascade.

    PubMed

    Jia, Yong-Sen; Hu, Xue-Qin; Gabriella, Hegyi; Qin, Li-Juan; Meggyeshazi, Nora

    2015-01-01

    Objective. The purpose of the study was to elucidate the molecular mechanism of tenacissoside H (TDH) inhibiting esophageal carcinoma infiltration and proliferation. Methods. In vitro, EC9706 cells were treated with TDH. Cells proliferation and cell cycle were assayed. PI3K and NF-κB mRNAs expression were determined by real time PCR. In vivo, model of nude mice with tumor was established. Mice were treated with TDH. Inhibition ratio of tumor volume was calculated. PCNA expression was examined. Protein expression in PI3K/Akt-NF-κB signaling pathway was determined. Results. In vitro, TDH significantly inhibited cells proliferation in a time-and-dose-dependent manner. TDH arrested the cell cycle in S phase and significantly inhibited PI3K and NF-κB mRNA expression, compared with blank controlled group (P < 0.05). In vivo, TDH strongly inhibits tumor growth and volume. PCNA expression was significantly decreased after treatment of TDH. TDH downregulated proteins expression in PI3K/Akt-NF-κB transduction cascade (P < 0.05). Conclusion. TDH inhibited esophageal carcinoma infiltration and proliferation both in vitro and in vivo. The anticancer activity has relation to arresting the cell cycle at the S phase, inhibited the PCNA expression of transplanted tumors in nude mice, and regulated the protein expression in the PI3K/Akt-NF-κB transduction cascade.

  5. Costunolide and dehydrocostuslactone combination treatment inhibit breast cancer by inducing cell cycle arrest and apoptosis through c-Myc/p53 and AKT/14-3-3 pathway

    PubMed Central

    Peng, Zhangxiao; Wang, Yan; Fan, Jianhui; Lin, Xuejing; Liu, Chunying; Xu, Yang; Ji, Weidan; Yan, Chao; Su, Changqing

    2017-01-01

    Our previous studies demonstrated that volatile oil from saussurea lappa root (VOSL), rich in two natural sesquiterpene lactones, costunolide (Cos) and dehydrocostuslactone (Dehy), exerts better anti-breast cancer efficacy and lower side effects than Cos or Dehy alone in vivo, however, their anti-cancer molecular mechanisms were still unknown. In this study, we investigated the underlying mechanisms of Cos and Dehy combination treatment (CD) on breast cancer cells through proteomics technology coupled with Western blot validation. Ingenuity Pathways Analysis (IPA) results based on the differentially expressed proteins revealed that both VOSL and CD affect the 14-3-3-mediated signaling, c-Myc mediated apoptosis signaling and protein kinase A (PKA) signaling. Western blot coupled with cell cycle and apoptosis analysis validated the results of proteomics analysis. Cell cycle arrest and apoptosis were induced in a dose-dependent manner, and the expressions of p53 and p-14-3-3 were significantly up-regulated, whereas the expressions of c-Myc, p-AKT, p-BID were significantly down-regulated, furthermore, the ratio of BAX/BCL-2 were significantly increased in breast cancer cells after CD and VOSL treatment. The findings indicated that VOSL and CD could induce breast cancer cell cycle arrest and apoptosis through c-Myc/p53 and AKT/14-3-3 signaling pathways and may be novel effective candidates for breast cancer treatment. PMID:28117370

  6. 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

    2015-12-08

    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.

  7. 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

  8. Quercetin induces apoptosis and cell cycle arrest in triple-negative breast cancer cells through modulation of Foxo3a activity.

    PubMed

    Nguyen, Lich Thi; Lee, Yeon-Hee; Sharma, Ashish Ranjan; Park, Jong-Bong; Jagga, Supriya; Sharma, Garima; Lee, Sang-Soo; Nam, Ju-Suk

    2017-03-01

    Quercetin, a plant-derived flavonoid found in fruits, vegetables and tea, has been known to possess bioactive properties such as anti-oxidant, anti-inflammatory and anti-cancer. In this study, anti-cancer effect of quercetin and its underlying mechanisms in triple-negative breast cancer cells was investigated. MTT assay showed that quercetin reduced breast cancer cell viability in a time and dose dependent manner. For this, quercetin not only increased cell apoptosis but also inhibited cell cycle progression. Moreover, quercetin increased FasL mRNA expression and p51, p21 and GADD45 signaling activities. We also observed that quercetin induced protein level, transcriptional activity and nuclear translocation of Foxo3a. Knockdown of Foxo3a caused significant reduction in the effect of quercetin on cell apoptosis and cell cycle arrest. In addition, treatment of JNK inhibitor (SP 600125) abolished quercetin-stimulated Foxo3a activity, suggesting JNK as a possible upstream signaling in regulation of Foxo3a activity. Knockdown of Foxo3a and inhibition of JNK activity reduced the signaling activities of p53, p21 and GADD45, triggered by quercetin. Taken together, our study suggests that quercetin induces apoptosis and cell cycle arrest via modification of Foxo3a signaling in triple-negative breast cancer cells.

  9. Cell cycle arrest and apoptosis induced by aspidin PB through the p53/p21 and mitochondria-dependent pathways in human osteosarcoma cells.

    PubMed

    Wan, Daqian; Jiang, Chaoyin; Hua, Xin; Wang, Ting; Chai, Yimin

    2015-10-01

    Aspidin PB is a natural product extracted from Dryopteris fragrans (L.) Schott, which has been characterized for its various biological activities. We reported that aspidin PB induced cell cycle arrest and apoptosis through the p53/p21 and mitochondria-dependent pathways in human osteosarcoma cells. Aspidin PB inhibited the proliferation of Saos-2, U2OS, and HOS cells in a dose-dependent and time-dependent manner. Aspidin PB induced changes in the cell cycle regulators (cyclin A, pRb, CDK2, p53, and p21), which caused cell cycle arrest in the S phase. We also explored the role of siRNA targeted to p53; it led to a dose-dependent attenuation of aspidin PB-induced apoptosis signaling. Moreover, after treatment with aspidin PB, the p21-silenced cells decreased significantly at the S phase. Aspidin PB increased the percentage of cells with mitochondrial membrane potential disruption. Western blot analysis showed that aspidin PB inhibited Bcl-2 expression and induced Bax expression to disintegrate the outer mitochondrial membrane and caused cytochrome C release. Mitochondrial cytochrome C release was associated with the activation of caspase-9 and caspase-3 cascades. Furthermore, the double-stranded DNA breaks and reactive oxygen species signaling were both involved in aspidin PB-induced DNA damage. In addition, aspidin PB inhibited tumor growth significantly in U2OS xenografts. Above all, we conclude that aspidin PB represents a valuable natural source and may potentially be applicable in osteosarcoma therapy.

  10. Quercetin induces apoptosis and cell cycle arrest in triple-negative breast cancer cells through modulation of Foxo3a activity

    PubMed Central

    Nguyen, Lich Thi; Lee, Yeon-Hee; Sharma, Ashish Ranjan; Park, Jong-Bong; Jagga, Supriya; Sharma, Garima

    2017-01-01

    Quercetin, a plant-derived flavonoid found in fruits, vegetables and tea, has been known to possess bioactive properties such as anti-oxidant, anti-inflammatory and anti-cancer. In this study, anti-cancer effect of quercetin and its underlying mechanisms in triple-negative breast cancer cells was investigated. MTT assay showed that quercetin reduced breast cancer cell viability in a time and dose dependent manner. For this, quercetin not only increased cell apoptosis but also inhibited cell cycle progression. Moreover, quercetin increased FasL mRNA expression and p51, p21 and GADD45 signaling activities. We also observed that quercetin induced protein level, transcriptional activity and nuclear translocation of Foxo3a. Knockdown of Foxo3a caused significant reduction in the effect of quercetin on cell apoptosis and cell cycle arrest. In addition, treatment of JNK inhibitor (SP 600125) abolished quercetin-stimulated Foxo3a activity, suggesting JNK as a possible upstream signaling in regulation of Foxo3a activity. Knockdown of Foxo3a and inhibition of JNK activity reduced the signaling activities of p53, p21 and GADD45, triggered by quercetin. Taken together, our study suggests that quercetin induces apoptosis and cell cycle arrest via modification of Foxo3a signaling in triple-negative breast cancer cells. PMID:28280414

  11. Far3p domains involved in the interactions of Far proteins and pheromone-induced cell cycle arrest in budding yeast.

    PubMed

    Lai, Fenju; Wu, Rentian; Wang, Jiafeng; Li, Chunming; Zou, Lan; Lu, Yongjun; Liang, Chun

    2011-02-01

    Far3p (factor arrest), a protein that interacts with Far7-11p, is required for the pheromone-mediated cell cycle arrest in G1 phase. We used a combination of computational and experimental strategies to identify the Far3p self-association, to map the Far3p domains that interact with Far3p itself and with other Far proteins, and to reveal the importance of the two coiled-coil motifs of Far3p in the integrity and function of the Far complex. We show that Far3p self-associates through its central region and its C-terminal coiled-coil domain, that the amino acid 61-100 region of Far3p interacts with Far7p, and that the Far3p N-terminal coiled-coil domain interacts with Far9p and Far10p. Mutation of the N-terminal coiled coil disrupts the interactions of Far3p with Far9p and Far10p, and mutation of the C-terminal domain weakens the Far3p self-interaction. Although the N- and C-terminal coiled-coil mutants reserve some of the interactions with itself and some other Far proteins, both mutants are defective in the pheromone-mediated G1 arrest, indicating that both coiled-coil motifs of Far3p are essential for the integrity and the function of the Far complex.

  12. Generation recruitment and death of brain cells throughout the life cycle of Sorex shrews (Lipotyphla).

    PubMed

    Bartkowska, Katarzyna; Djavadian, Rouzanna L; Taylor, Jan R E; Turlejski, Kris

    2008-04-01

    Young shrews of the genus Sorex that are born in early summer reduce their body size before wintering, including a reduction of brain weight of 10-30%. In the spring they mature sexually, double their body weight and regain about half of the loss in brain weight. To investigate the mechanisms of brain weight oscillations we studied the rate of cell death and generation in the brain during the whole life cycle of the common shrew (Sorex araneus) and pygmy shrew (S. minutus). After weaning, shrews generate new brain cells in only two mammalian neurogenic zones and approximately 80% of these develop into neurones. The increase of the shrew brain weight in the spring did not depend on recruitment of new cells. Moreover, adult Sorex shrews did not generate new cells in the dentate gyri. Injections of 5-HT1A receptor agonists in the adult shrews induced neurogenesis in their dentate gyri, showing the presence of dormant progenitor cells. Generation of new neurones in the subventricular zone of the lateral ventricles and their recruitment to olfactory bulbs continued throughout life. TUNEL labelling showed that the rate of cell death in all brain structures, including the proliferation zones and olfactory bulb, was very low throughout life. We conclude that neither cell death nor recruitment significantly contributes to seasonal oscillations and the net loss of brain weight in the Sorex shrews. With the exception of dentate gyrus and olfactory bulb, cellular populations of brain structures are stable throughout the life cycle of these shrews.

  13. MeHg Developing Exposure Causes DNA Double-Strand Breaks and Elicits Cell Cycle Arrest in Spinal Cord Cells

    PubMed Central

    Ferreira, Fabiana F.; Ammar, Dib; Bourckhardt, Gilian F.; Kobus-Bianchini, Karoline; Müller, Yara M. R.; Nazari, Evelise M.

    2015-01-01

    The neurotoxicity caused by methylmercury (MeHg) is well documented; however, the developmental neurotoxicity in spinal cord is still not fully understood. Here we investigated whether MeHg affects the spinal cord layers development. Chicken embryos at E3 were treated in ovo with 0.1 μg MeHg/50 μL saline solution and analyzed at E10. Thus, we performed immunostaining using anti-γ-H2A.X to recognize DNA double-strand breaks and antiphosphohistone H3, anti-p21, and anti-cyclin E to identify cells in proliferation and cell cycle proteins. Also, to identify neuronal cells, we used anti-NeuN and anti-βIII-tubulin antibodies. After the MeHg treatment, we observed the increase on γ-H2A.X in response to DNA damage. MeHg caused a decrease in the proliferating cells and in the thickness of spinal cord layers. Moreover, we verified that MeHg induced an increase in the number of p21-positive cells but did not change the cyclin E-positive cells. A significantly high number of TUNEL-positive cells indicating DNA fragmentation were observed in MeHg-treated embryos. Regarding the neuronal differentiation, MeHg induced a decrease in NeuN expression and did not change the expression of βIII-tubulin. These results showed that in ovo MeHg exposure alters spinal cord development by disturbing the cell proliferation and death, also interfering in early neuronal differentiation. PMID:26793240

  14. The retinoblastoma protein-associated cell cycle arrest in S-phase under moderate hypoxia is disrupted in cells expressing HPV18 E7 oncoprotein.

    PubMed Central

    Amellem, O.; Sandvik, J. A.; Stokke, T.; Pettersen, E. O.

    1998-01-01

    We have studied the role of the oxygen-dependent pyrimidine metabolism in the regulation of cell cycle progression under moderate hypoxia in human cell lines containing functional (T-47D) or non-functional (NHIK 3025, SAOS-2) retinoblastoma gene product (pRB). Under aerobic conditions, pRB exerts its growth-regulatory effects during early G1 phase of the cell cycle, when all pRB present has been assumed to be in the underphosphorylated form and bound in the nucleus. We demonstrate that pRB is dephosphorylated and re-bound in the nucleus in approximately 90% of T-47D cells located in S and G2 phases under moderately hypoxic conditions. Under these conditions, no T-47D cells entered S-phase, and no progression through S-phase was observed. Progression of cells through G2 and mitosis seems independent of their functional pRB status. The p21WAF1/CIP1 protein level was significantly reduced by moderate hypoxia in p53-deficient T-47D cells, whereas p16(INK4a) was not expressed in these cells, suggesting that the hypoxia-induced cell cycle arrest is independent of these cyclin-dependent kinase inhibitors. The addition of pyrimidine deoxynucleosides did not release T-47D cells, containing mainly underphosphorylated pRB, from the cell cycle arrest induced by moderate hypoxia. However, NHIK 3025 cells, in which pRB is abrogated by expression of the HPV18 E7 oncoprotein, and SAOS-2 cells, which lack pRB expression, continued cell cycle progression under moderate hypoxia provided that excess pyrimidine deoxynucleosides were present. NHIK 3025 cells express high levels of p16INK4a under both aerobic and moderately hypoxic conditions, suggesting that the inhibitory function of p16(INK4a) would not be manifested in such pRB-deficient cells. Thus, pRB, a key member of the cell cycle checkpoint network, seems to play a major role by inducing growth arrest under moderate hypoxia, and it gradually overrides hypoxia-induced suppression of pyrimidine metabolism in the regulation of

  15. MiR-371-373 cluster acts as a tumor-suppressor-miR and promotes cell cycle arrest in unrestricted somatic stem cells.

    PubMed

    Langroudi, Lida; Jamshidi-Adegani, Fatemeh; Shafiee, Abbas; Rad, Seyed Mohammad Ali Hosseini; Keramati, Farid; Azadmanesh, Kayhan; Arefian, Ehsan; Soleimani, Masoud

    2015-09-01

    Recent advances in small RNA research have implicated microRNAs (miRNAs) as important regulators of proliferation and development. The miR-371-373 cluster is prominently expressed in human embryonic stem cells (ESCs) and rapidly decreases after cell differentiation. MiR-371-373 cluster was investigated as one of the key factors of stem cell maintenance and pluripotency in unrestricted somatic stem cells (USSCs) using a lentivirus system. Gene expression showed a dual effect on proliferation, which revealed a transient cell cycle progression and consequent repression in pluripotency factors and cell cycle genes. Cell proliferation analysis with CFU, MTT, and DNA content assays further confirmed the dual effect of cluster after prolonged exposure. Analyzing the course of action, it seems that miR-371-373 cluster acts as an onco/tumor suppressor-miR. MiR371-373 cluster acts by modulating the function of these factors and limiting the excessive cell cycle propagation upon oncogenic stimuli to protect cells from replicative stress, but also activate CDK inhibitors and transcriptional repressors of the retinoblastoma family to cause cell cycle arrest. In contrast to the previous studies, we believe that miR-371-373 cluster functions as a self-renewal miRNA to induce and maintain the pluripotent state but also to potentially inhibit dysregulated proliferation through cell cycle arrest. It seems that miR-371-373 cluster presents with a dual effect in this cellular context which may possess different actions in various cells. This not only expands the basic knowledge of the cluster but may offer a great chance for therapeutic interventions.

  16. Condurango glycoside-rich components stimulate DNA damage-induced cell cycle arrest and ROS-mediated caspase-3 dependent apoptosis through inhibition of cell-proliferation in lung cancer, in vitro and in vivo.

    PubMed

    Sikdar, Sourav; Mukherjee, Avinaba; Ghosh, Samrat; Khuda-Bukhsh, Anisur Rahman

    2014-01-01

    Chemotherapeutic potential of Condurango glycoside-rich components (CGS) was evaluated in NSCLC, in vitro and in BaP-intoxicated rats, in vivo. NSCLC cells were treated with different concentrations of CGS to test their effect on cell viability. Cellular morphology, DNA-damage, AnnexinV-FITC/PI, cell cycle regulation, ROS-accumulation, MMP, and expressions of related signalling genes were critically analysed. 0.22 μg/μl CGS (IC₅₀ dose at 24 h) was selected for the study. CGS-induced apoptosis via DNA damage was evidenced by DNA-ladder formation, increase of AnnexinV-positive cells, cell cycle arrest at subG0/G1 and differential expressions of apoptotic genes. ROS-elevation and MMP-depolarization with significant caspase-3 activation might lead to apoptotic cell death. Anti-proliferative activity was confirmed by EGFR-expression modulation. ROS accumulation and DNA-nick formation with tissue damage-repair activity after post-cancerous CGS treatment, in vivo, supported the in vitro findings. Overall results advocate considerable apoptosis-inducing potential of CGS against NSCLC, validating its use against lung cancer by CAM practitioners.

  17. G1 cell cycle arrest due to the inhibition of erbB family receptor tyrosine kinases does not require the retinoblastoma protein

    SciTech Connect

    Gonzales, Andrea J. . E-mail: Andrea.Gonzales@pfizer.com; Fry, David W.

    2005-02-01

    The erbB receptor family (EGFr, erbB-2, erbB-3, and erbB-4) consists of transmembrane glycoproteins that transduce extracellular signals to the nucleus when activated. erbB family members are widely expressed in epithelial, mesenchymal, and neuronal cells and contribute to the proliferation, differentiation, migration, and survival of these cell types. The present study evaluates the effects of erbB family signaling on cell cycle progression and the role that pRB plays in regulating this process. ErbB family RTK activity was inhibited by PD 158780 in the breast epithelial cell line MCF10A. PD 158780 (0.5 {mu}M) inhibited EGF-stimulated and heregulin-stimulated autophosphorylation and caused a G1 cell cycle arrest within 24 h, which correlated with hypophosporylation of pRB. MCF10A cells lacking functional pRB retained the ability to arrest in G1 when treated with PD 158780. Both cell lines showed induction of p27{sup KIP1} protein when treated with PD 158780 and increased association of p27{sup KIP1} with cyclin E-CDK2. Furthermore, CDK2 kinase activity was dramatically inhibited with drug treatment. Changes in other pRB family members were noted with drug treatment, namely a decrease in p107 and an increase in p130. These findings show that the G1 arrest induced through inhibition of erbB family RTK activity does not require functional pRB.

  18. Kaposi's Sarcoma-Associated Herpesvirus MicroRNAs Target GADD45B To Protect Infected Cells from Cell Cycle Arrest and Apoptosis.

    PubMed

    Liu, Xiaoyan; Happel, Christine; Ziegelbauer, Joseph M

    2017-02-01

    Kaposi's sarcoma is one of the most common malignancies in HIV-infected individuals. The responsible agent, Kaposi's sarcoma-associated herpesvirus (KSHV; HHV8), expresses multiple microRNAs (miRNAs), but the targets and functions of these miRNAs are not completely understood. After infection in primary endothelial cells with KSHV, growth arrest DNA damage-inducible gene 45 beta (GADD45B) is one of the most repressed genes using genomic expression profiling. GADD45B was also repressed in mRNA expression profiling experiments when KSHV miRNAs were introduced to uninfected cells. We hypothesized that KSHV miRNAs target human GADD45B to protect cells from consequences of DNA damage, which can be triggered by viral infection. Expression of GADD45B protein is induced by the p53 activator, Nutlin-3, and KSHV miRNA-K9 inhibits this induction. In addition, Nutlin-3 increased apoptosis and cell cycle arrest based on flow cytometry assays. KSHV miR-K9 protected primary endothelial cells from apoptosis and cell cycle arrest following Nutlin-3 treatment. Similar protective phenotypes were seen for targeting GADD45B with short interfering RNAs (siRNAs), as with miR-K9. KSHV miR-K9 also decreased the protein levels of cleaved caspase-3, cleaved caspase-7, and cleaved poly(ADP-ribose) polymerase (PARP). In B lymphocytes latently infected with KSHV, specific inhibitors of KSHV miR-K9 led to increased GADD45B expression and apoptosis, indicating that miR-K9 is important for reducing apoptosis in infected cells. Furthermore, ectopic expression of GADD45B in KSHV-infected cells promoted apoptosis. Together, these results identify a new miRNA target and demonstrate that KSHV miRNAs are important for protecting infected cells from DNA damage responses.

  19. 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

  20. Combined Effect of Silica Nanoparticles and Benzo[a]pyrene on Cell Cycle Arrest Induction and Apoptosis in Human Umbilical Vein Endothelial Cells

    PubMed Central

    Asweto, Collins Otieno; Wu, Jing; Hu, Hejing; Feng, Lin; Yang, Xiaozhe; Duan, Junchao; Sun, Zhiwei

    2017-01-01

    Particulate matter (PM) such as ultrafine particulate matter (UFP) and the organic compound pollutants such as polycyclic aromatic hydrocarbon (PAH) are widespread in the environment. UFP and PAH are present in the air, and their presence may enhance their individual adverse effects on human health. However, the mechanism and effect of their combined interactions on human cells are not well understood. We investigated the combined toxicity of silica nanoparticles (SiNPs) (UFP) and Benzo[a]pyrene (B[a]P) (PAH) on human endothelial cells. Human umbilical vascular endothelial cells (HUVECs) were exposed to SiNPs or B[a]P, or a combination of SiNPs and B[a]P. The toxicity was investigated by assessing cellular oxidative stress, DNA damage, cell cycle arrest, and apoptosis. Our results show that SiNPs were able to induce reactive oxygen species generation (ROS). B[a]P, when acting alone, had no toxicity effect. However, a co-exposure of SiNPs and B[a]P synergistically induced DNA damage, oxidative stress, cell cycle arrest at the G2/M check point, and apoptosis. The co-exposure induced G2/M arrest through the upregulation of Chk1 and downregulation of Cdc25C, cyclin B1. The co-exposure also upregulated bax, caspase-3, and caspase-9, the proapoptic proteins, while down-regulating bcl-2, which is an antiapoptotic protein. These results show that interactions between SiNPs and B[a]P synergistically potentiated toxicological effects on HUVECs. This information should help further our understanding of the combined toxicity of PAH and UFP. PMID:28282959

  1. Genetically engineered pre-microRNA-34a prodrug suppresses orthotopic osteosarcoma xenograft tumor growth via the induction of apoptosis and cell cycle arrest

    PubMed Central

    Zhao, Yong; Tu, Mei-Juan; Wang, Wei-Peng; Qiu, Jing-Xin; Yu, Ai-Xi; Yu, Ai-Ming

    2016-01-01

    Osteosarcoma (OS) is the most common primary malignant bone tumor in children, and microRNA-34a (miR-34a) replacement therapy represents a new treatment strategy. This study was to define the effectiveness and safety profiles of a novel bioengineered miR-34a prodrug in orthotopic OS xenograft tumor mouse model. Highly purified pre-miR-34a prodrug significantly inhibited the proliferation of human 143B and MG-63 cells in a dose dependent manner and to much greater degrees than controls, which was attributed to induction of apoptosis and G2 cell cycle arrest. Inhibition of OS cell growth and invasion were associated with release of high levels of mature miR-34a from pre-miR-34a prodrug and consequently reduction of protein levels of many miR-34a target genes including SIRT1, BCL2, c-MET, and CDK6. Furthermore, intravenous administration of in vivo-jetPEI formulated miR-34a prodrug significantly reduced OS tumor growth in orthotopic xenograft mouse models. In addition, mouse blood chemistry profiles indicated that therapeutic doses of bioengineered miR-34a prodrug were well tolerated in these animals. The results demonstrated that bioengineered miR-34a prodrug was effective to control OS tumor growth which involved the induction of apoptosis and cell cycle arrest, supporting the development of bioengineered RNAs as a novel class of large molecule therapeutic agents. PMID:27216562

  2. W346 inhibits cell growth, invasion, induces cycle arrest and potentiates apoptosis in human gastric cancer cells in vitro through the NF-κB signaling pathway.

    PubMed

    Xia, Yiqun; Weng, Bixia; Wang, Zhankun; Kang, Yanting; Shi, Lingyi; Huang, Guanqun; Ying, Shilong; Du, Xiaojing; Chen, Qiuxiang; Jin, Rong; Wu, Jianzhang; Liang, Guang

    2016-04-01

    The therapeutic agent selectively killing cancer cells is urgently needed for gastric cancer treatment. Curcumin has been investigated for its effect on the cancer treatment because of its significant therapeutic potential and safety profile. A synthetic unsymmetry mono-carbonyl compound termed W346 was developed from curcumin. In this study, we investigated the potential antineoplastic effect and mechanism of W346 against human gastric cancer cells. W346 suppressed the proliferation and invasion, blocked cell cycle arrest at G2/M phase, and increased apoptosis in gastric cancer cells, and it presented obviously improved anticancer activity than curcumin. Moreover, W346 effectively inhibited tumor necrosis factor (TNF-α)-induced NF-κB activation by suppressing IKK phosphorylation, inhibiting IκB-α degradation, and restraining the accumulation of NF-κB subunit p65 nuclear translocation. W346 also affected NF-κB-regulated downstream products involved in cycle arrest and apoptosis. In a word, W346 exhibited significantly improved anti-gastric cancer activity over curcumin by targeting NF-κB signaling pathway, and it is likely to be a promising starting point for the development of curcumin-based therapeutic agent.

  3. Chaetoglobosin K induces apoptosis and G2 cell cycle arrest through p53-dependent pathway in cisplatin-resistant ovarian cancer cells.

    PubMed

    Li, Bo; Gao, Ying; Rankin, Gary O; Rojanasakul, Yon; Cutler, Stephen J; Tu, Youying; Chen, Yi Charlie

    2015-01-28

    Adverse side effects and acquired resistance to conventional platinum based chemotherapy have become major impediments in ovarian cancer treatment, and drive the development of more selective anticancer drugs. Chaetoglobosin K (ChK) was shown to have a more potent growth inhibitory effect than cisplatin on two cisplatin-resistant ovarian cancer cell lines, OVCAR-3 and A2780/CP70, and was less cytotoxic to a normal ovarian cell line, IOSE-364, than to the cancer cell lines. Hoechst 33342 staining and Flow cytometry analysis indicated that ChK induced preferential apoptosis and G2 cell cycle arrest in both ovarian cancer cells with respect to the normal ovarian cells. ChK induced apoptosis through a p53-dependent caspase-8 activation extrinsic pathway, and caused G2 cell cycle arrest via cyclin B1 by increasing p53 expression and p38 phosphorylation in OVCAR-3 and A2780/CP70 cells. DR5 and p21 might play an important role in determining the sensitivity of normal and malignant ovarian cells to ChK. Based on these results, ChK would be a potential compound for treating platinum-resistant ovarian cancer.

  4. Gleditsia sinensis thorn extract inhibits human colon cancer cells: the role of ERK1/2, G2/M-phase cell cycle arrest and p53 expression.

    PubMed

    Lee, Se-Jung; Park, Keerang; Ha, Sang-Do; Kim, Wun-Jae; Moon, Sung-Kwon

    2010-12-01

    The thorns of Gleditsia sinensis are used as a medicinal herb in China and Korea. However, the mechanisms responsible for the antitumor effects of the water extract of Gleditsia sinensis thorns (WEGS) remain unknown. HCT116 cells treated with the WEGS at a dose of 800 μg/mL (IC₅₀) showed a significant decrease in cell growth and an increase in cell cycle arrest during the G2/M-phase. G2/M-phase arrest was correlated with increased p53 levels and down-regulation of the check-point proteins, cyclinB1, Cdc2 and Cdc25c. In addition, treatment with WEGS induced phosphorylation of extracellular signal-regulated kinase (ERK), p38 MAP kinase and JNK (c-Jun N-terminal kinases). Moreover, inhibition of ERK by treatment of cells with the ERK-specific inhibitor PD98059 blocked WEGS-mediated p53 expression. Similarly, blockage of ERK function in the WEGS-treated cells reversed cell-growth inhibition and decreased cell cycle proteins. Finally, in vivo WEGS treatment significantly inhibited the growth of HCT116 tumor cell xenografts in nude mice with no negative side effects, including loss of body weight. These results describe the molecular mechanisms whereby the WEGS might inhibit proliferation of colon cancer both in vitro and in vivo, suggesting that WEGS has potential as an anticancer agent for the treatment of malignancies.

  5. Development of cell-based quantitative evaluation method for cell cycle-arrest type cancer drugs for apoptosis by high precision surface plasmon resonance sensor

    NASA Astrophysics Data System (ADS)

    Ona, Toshihiro; Nishijima, Hiroshi; Kosaihira, Atsushi; Shibata, Junko

    2008-04-01

    In vitro rapid and quantitative cell-based assay is demanded to verify the efficacy prediction of cancer drugs since a cancer patient may have unconventional aspects of tumor development. Here, we show the rapid and non-label quantitative verifying method and instrumentation of apoptosis for cell cycle-arrest type cancer drugs (Roscovitine and D-allose) by reaction analysis of living liver cancer cells cultured on a sensor chip with a newly developed high precision (50 ndeg s -1 average fluctuation) surface plasmon resonance (SPR) sensor. The time-course cell reaction as the SPR angle change rate for 10 min from 30 min cell culture with a drug was significantly related to cell viability. By the simultaneous detection of differential SPR angle change and fluorescence by specific probes using the new instrument, the SPR angle was related to the nano-order potential decrease in inner mitochondrial membrane potential. The results obtained are universally valid for the cell cycle-arrest type cancer drugs, which mediate apoptosis through different cell-signaling pathways, by a liver cancer cell line of Hep G2 (P<0.001). This system towards the application to evaluate personal therapeutic potentials of drugs using cancer cells from patients in clinical use.

  6. 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

  7. Antrodia camphorata induces G(1) cell-cycle arrest in human premyelocytic leukemia (HL-60) cells and suppresses tumor growth in athymic nude mice.

    PubMed

    Yang, Hsin-Ling; Kumar, K J Senthil; Kuo, Ya-Ting; Chang, Hebron C; Liao, Jiunn-Wang; Hsu, Li-Sung; Hseu, You-Cheng

    2014-09-01

    Antrodia camphorata is a well-known medicinal mushroom in Taiwan. The broth from a fermented culture of Antrodia camphorata (AC) has been shown to induce apoptosis in cultured human premyelocytic leukemia (HL-60) cells. In the present study, we examined the effects of AC on cell cycle arrest in vitro in HL-60 cells and on tumor regression in vivo using an athymic nude mouse model. We found that AC (20-80 μg mL(-1)) treatment significantly induced G1 cell-cycle arrest in HL-60 cells by reducing the levels of cyclin D1, CDK4, cyclin E, CDK2, cyclin A, and phosphorylation of retinoblastoma protein (p-Rb). Moreover, AC treatment led to significantly increased protein expression levels of CDK inhibitors, including p21(WAF1) and p15(NIK4B). Additionally, AC treatment markedly induced intracellular ROS generation and mitochondrial dysfunction in HL-60 cells. Furthermore, the in vivo study results revealed that AC treatment was effective in terms of delaying the tumor incidence in nude mice that had been inoculated with HL-60 cells as well as in reducing the tumor burden. Histological analysis confirmed that AC treatment significantly modulated the xenografted tumor progression as demonstrated by a reduction in mitotic cells. Our data strongly suggest that Antrodia camphorata could be an anti-cancer agent for human leukemia.

  8. 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.

  9. Human parvovirus B19 DNA replication induces a DNA damage response that is dispensable for cell cycle arrest at phase G2/M.

    PubMed

    Lou, Sai; Luo, Yong; Cheng, Fang; Huang, Qinfeng; Shen, Weiran; Kleiboeker, Steve; Tisdale, John F; Liu, Zhengwen; Qiu, Jianming

    2012-10-01

    Human parvovirus B19 (B19V) infection is highly restricted to human erythroid progenitor cells, in which it induces a DNA damage response (DDR). The DDR signaling is mainly mediated by the ATR (ataxia telangiectasia-mutated and Rad3-related) pathway, which promotes replication of the viral genome; however, the exact mechanisms employed by B19V to take advantage of the DDR for virus replication remain unclear. In this study, we focused on the initiators of the DDR and the role of the DDR in cell cycle arrest during B19V infection. We examined the role of individual viral proteins, which were delivered by lentiviruses, in triggering a DDR in ex vivo-expanded primary human erythroid progenitor cells and the role of DNA replication of the B19V double-stranded DNA (dsDNA) genome in a human megakaryoblastoid cell line, UT7/Epo-S1 (S1). All the cells were cultured under hypoxic conditions. The results showed that none of the viral proteins induced phosphorylation of H2AX or replication protein A32 (RPA32), both hallmarks of a DDR. However, replication of the B19V dsDNA genome was capable of inducing the DDR. Moreover, the DDR per se did not arrest the cell cycle at the G(2)/M phase in cells with replicating B19V dsDNA genomes. Instead, the B19V nonstructural 1 (NS1) protein was the key factor in disrupting the cell cycle via a putative transactivation domain operating through a p53-independent pathway. Taken together, the results suggest that the replication of the B19V genome is largely responsible for triggering a DDR, which does not perturb cell cycle progression at G(2)/M significantly, during B19V infection.

  10. Inhibition of NF-kappaB by combination therapy with parthenolide and hyperthermia and kinetics of apoptosis induction and cell cycle arrest in human lung adenocarcinoma cells.

    PubMed

    Hayashi, Sachiko; Sakurai, Hiroaki; Hayashi, Akio; Tanaka, Yukie; Hatashita, Masanori; Shioura, Hiroki

    2010-01-01

    We investigated the mechanisms of thermosensitization related to combination therapy with sesquiterpene lactone parthenolide (PTL), a nuclear factor-kappaB (NF-kappaB) inhibitor, and hyperthermia using human lung adenocarcinoma cells A549. The kinetics of apoptosis induction and cell cycle of cells treated with PTL, heating, and combined treatment were examined by flow cytometric analysis. The flow cytometric distribution was calculated and expressed as a percentage. The ratios of the sub-G1 division, used to determine the induction of apoptosis, increased significantly with the combination therapy. Furthermore, the ratios of G2/M division increased and the ratios of G0/G1 division decreased, indicating cell cycle arrest in G2/M. The cell phase response to PTL by A549 cells synchronized in the G1/S border with hydroxyurea was also analyzed. PTL showed remarkable cytotoxicity at the S phase of the cell cycle in A549 cells at all concentrations as well as with hyperthermia, thus PTL reduced the number of cells in the proliferation phase. Inhibition of intracellular transcription factor NF-kappaB activation in A549 cells with various incubation periods after treatments with PTL, heating and combined treatment was examined by Western blot analysis. Unexpectedly, PTL alone did not inhibit NF-kappaB activation in cells stimulated with TNF-alpha, while heating alone inhibited NF-kappaB early after treatment and that effect faded over time. In contrast, PTL combined with heating completely inhibited NF-kappaB activation. Our results demonstrated that PTL and heating in combination cause significant thermosensitization of A549 cells via induction of apoptosis or cell cycle arrest in G2/M by inhibiting NF-kappaB activation in a synergistic manner.

  11. Induction of G2/M phase cell cycle arrest and apoptosis by ginsenoside Rf in human osteosarcoma MG‑63 cells through the mitochondrial pathway.

    PubMed

    Shangguan, Wen-Ji; Li, He; Zhang, Yue-Hui

    2014-01-01

    Ginsenosides, extracted from the traditional Chinese herb ginseng, are a series of novel natural anticancer products known for their favorable safety and efficacy profiles. The present study aimed to investigate the cytotoxicity of ginsenoside Rf to human osteosarcoma cells and to explore the anticancer molecular mechanisms of ginsenoside Rf. Five human osteosarcoma cell lines (MG-63, OS732, U-2OS, HOS and SAOS-2) were employed to investigate the cytotoxicity of ginsenoside Rf by MTT and colony forming assays. After treatment with ginsenoside Rf, MG-63 cells which were the most sensitive to ginsenoside Rf, were subjected to flow cytometry to detect cell cycle distribution and apoptosis, and nuclear morphological changes were visualized by Hoechst 33258 staining. Caspase-3, -8 and -9 activities were also evaluated. The expression of cell cycle markers including cyclin B1 and Cdk1 was detected by RT-PCR and western blotting. The expression of apoptotic genes Bcl-2 and Bax and the release of cytochrome c were also examined by western blotting. Change in the mitochondrial membrane potential was observed by JC-1 staining in situ. Our results demonstrated that the cytotoxicity of ginsenoside Rf to these human osteosarcoma cell lines was dose-dependent, and the MG-63 cells were the most sensitive to exposure to ginsenoside Rf. Additionally, ginsenoside Rf induced G2/M phase cell cycle arrest and apoptosis in MG-63 cells. Furthermore, we observed upregulation of Bax and downregulation of Bcl-2, Cdk1 and cyclin B1, the activation of caspase-3 and -9 and the release of cytochrome c in MG-63 cells following treatment with ginsenoside Rf. Our findings demonstrated that ginsenoside Rf induces G2/M phase cell cycle arrest and apoptosis in human osteosarcoma MG-63 cells through the mitochondrial pathway, suggesting that ginsenoside Rf, as an effective natural product, may have a therapeutic effect on human osteosarcoma.

  12. Nucleolar Targeting by Platinum: p53-Independent Apoptosis Follows rRNA Inhibition, Cell-Cycle Arrest, and DNA Compaction

    PubMed Central

    2015-01-01

    TriplatinNC is a highly positively charged, substitution-inert derivative of the phase II clinical anticancer drug, BBR3464. Such substitution-inert complexes form a distinct subset of polynuclear platinum complexes (PPCs) interacting with DNA and other biomolecules through noncovalent interactions. Rapid cellular entry is facilitated via interaction with cell surface glycosoaminoglycans and is a mechanism unique to PPCs. Nanoscale secondary ion mass spectrometry (nanoSIMS) showed rapid distribution within cytoplasmic and nucleolar compartments, but not the nucleus. In this article, the downstream effects of nucleolar localization are described. In human colon carcinoma cells, HCT116, the production rate of 47S rRNA precursor transcripts was dramatically reduced as an early event after drug treatment. Transcriptional inhibition of rRNA was followed by a robust G1 arrest, and activation of apoptotic proteins caspase-8, -9, and -3 and PARP-1 in a p53-independent manner. Using cell synchronization and flow cytometry, it was determined that cells treated while in G1 arrest immediately, but cells treated in S or G2 successfully complete mitosis. Twenty-four hours after treatment, the majority of cells finally arrest in G1, but nearly one-third contained highly compacted DNA; a distinct biological feature that cannot be associated with mitosis, senescence, or apoptosis. This unique effect mirrored the efficient condensation of tRNA and DNA in cell-free systems. The combination of DNA compaction and apoptosis by TriplatinNC treatment conferred striking activity in platinum-resistant and/or p53 mutant or null cell lines. Taken together, our results support that the biological activity of TriplatinNC reflects reduced metabolic deactivation (substitution-inert compound not reactive to sulfur nucleophiles), high cellular accumulation, and novel consequences of high-affinity noncovalent DNA binding, producing a new profile and a further shift in the structure

  13. The bacterial cell cycle checkpoint protein Obg and its role in programmed cell death

    PubMed Central

    Dewachter, Liselot; Verstraeten, Natalie; Fauvart, Maarten; Michiels, Jan

    2016-01-01

    The phenomenon of programmed cell death (PCD), in which cells initiate their own demise, is not restricted to multicellular organisms. Unicellular organisms, both eukaryotes and prokaryotes, also possess pathways that mediate PCD. We recently identified a PCD mechanism in Escherichia coli that is triggered by a mutant isoform of the essential GTPase ObgE (Obg of E. coli). Importantly, the PCD pathway mediated by mutant Obg (Obg*) differs fundamentally from other previously described bacterial PCD pathways and thus constitutes a new mode of PCD. ObgE was previously proposed to act as a cell cycle checkpoint protein able to halt cell division. The implication of ObgE in the regulation of PCD further increases the similarity between this protein and eukaryotic cell cycle regulators that are capable of doing both. Moreover, since Obg is conserved in eukaryotes, the elucidation of this cell death mechanism might contribute to the understanding of PCD in higher organisms. Additionally, if Obg*-mediated PCD is conserved among different bacterial species, it will be a prime target for the development of innovative antibacterials that artificially induce this pathway.

  14. 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

  15. HEAT SHOCK FACTOR 1-MEDIATED THERMOTOLERANCE PREVENTS CELL DEATH AND RESULTS IN G2/M CELL CYCLE ARREST

    EPA Science Inventory

    Mammalian cells respond to stress by activating heat shock transcription factors (e.g., HSF1) that regulate increased synthesis of heat shock proteins (HSPs). HSPs mediate protection from deleterious effects of stress by preventing permanent disruption of normal cellular mitosis...

  16. Allyl-isatin suppresses cell viability, induces cell cycle arrest, and promotes cell apoptosis in hepatocellular carcinoma HepG2 cells.

    PubMed

    Bian, Weihua; An, Yukuan; Qu, Huiqing; Yang, Yue; Yang, Junhou; Xu, Yanyan

    2016-06-01

    The anticancer effect of the newly synthesized isatin derivative, N-allyl-isatin (Allyl-I), was evaluated in vitro with human hepatocellular carcinoma HepG2 cells. Cell viability was detected by cell counting kit-8 (CCK8) assay. Acridine orange (AO)/ethidium bromide (EB) double staining was used to observe the cell morphology. Flow cytometry was used to assess the effects of Allyl-I on the cell cycle, apoptosis rate, and mitochondrial membrane potential (MMP). Western blot analysis was performed to detect the influence of Ally1-I on the expression of cytochrome c (cyt c), Bax, Bcl-2, and cleaved caspase-3. Allyl-I significantly inhibited HepG2 cell viability in a time- and dose-dependent manner. Allyl-I can induce cell cycle arrest in HepG2 cells at the G2/M phase. Apoptotic nuclear morphological changes were observed after AO/EB double staining. Fluorescein isothiocyanate-conjugated Annexin V (Annexin V-FITC) and propidium iodide (PI) double staining showed that the apoptotic rates significantly increased in the presence of Allyl-I. Rhodamine 123 staining indicated that Allyl-I can decrease the MMP. Allyl-I also altered the expression of mitochondrial apoptosis-related proteins. Protein levels of cyt c and cleaved caspase-3 were upregulated following Allyl-I treatment. By contrast, the Bcl-2/Bax ratio decreased. Results suggest that Allyl-I suppresses cell viability, induces cell cycle arrest, and promotes cell apoptosis in HepG2 cells. Furthermore, the induction of apoptosis might be correlated with the mitochondrial pathway.

  17. RNA-binding motif protein 5 inhibits the proliferation of cigarette smoke-transformed BEAS-2B cells through cell cycle arrest and apoptosis.

    PubMed

    Lv, Xue-Jiao; Du, Yan-Wei; Hao, Yu-Qiu; Su, Zhen-Zhong; Zhang, Lin; Zhao, Li-Jing; Zhang, Jie

    2016-04-01

    Cigarette smoking has been shown to be the most significant risk factor for lung cancer. Recent studies have also indicated that RNA-binding motif protein 5 (RBM5) can modulate apoptosis and suppress tumor growth. The present study focused on the role of RBM5 in the regulation of cigarette smoke extract (CSE)-induced transformation of bronchial epithelial cells into the cancerous phenotype and its mechanism of action. Herein, we exposed normal BEAS-2B cells for 8 days to varying concentrations of CSE or dimethylsulfoxide (DMSO), followed by a recovery period of 2 weeks. Next, the RBM5 protein was overexpressed in these transformed BEAS-2B cells though lentiviral infection. Later, the morphological changes, cell proliferation, cell cycle, apoptosis, invasion and migration were assessed. In addition, we analyzed the role of RBM5 in xenograft growth. The expression of RBM5 along with the genes related to cell cycle regulation, apoptosis and invasion were also examined. Finally, our results revealed that BEAS-2B cells exposed to 100 µg/ml CSE acquired phenotypic changes and formed tumors in nude mice, indicative of their cancerous transformation and had reduced RBM5 expression. Subsequent overexpression of RBM5 in these cells significantly inhibited their proliferation, induced G1/S arrest, triggered apoptosis and inhibited their invasion and migration, including xenograft growth. Thus, we established an in vitro model of CSE-induced cancerous transformation and concluded that RBM5 overexpression inhibited the growth of these transformed cells through cell cycle arrest and induction of apoptosis. Therefore, our study suggests the importance of RBM5 in the pathogenesis of smoking-related cancer.

  18. Ajwa Date (Phoenix dactylifera L.) Extract Inhibits Human Breast Adenocarcinoma (MCF7) Cells In Vitro by Inducing Apoptosis and Cell Cycle Arrest

    PubMed Central

    Khan, Fazal; Ahmed, Farid; Pushparaj, Peter Natesan; Abuzenadah, Adel; Kumosani, Taha; Barbour, Elie; AlQahtani, Mohammed; Gauthaman, Kalamegam

    2016-01-01

    Introduction Phoenix dactylifera L (Date palm) is a native plant of the Kingdom of Saudi Arabia (KSA) and other Middle Eastern countries. Ajwa date has been described in the traditional and alternative medicine to provide several health benefits including anticholesteremic, antioxidant, hepatoprotective and anticancer effects, but most remains to be scientifically validated. Herein, we evaluated the anticancer effects of the Methanolic Extract of Ajwa Date (MEAD) on human breast adenocarcinoma (MCF7) cells in vitro. Methods MCF7 cells were treated with various concentrations (5, 10, 15, 20 and 25 mg/ml) of MEAD for 24, 48 and 72 h and changes in cell morphology, cell cycle, apoptosis related protein and gene expression were studied. Results Phase contrast microscopy showed various morphological changes such as cell shrinkage, vacuolation, blebbing and fragmentation. MTT (2-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay demonstrated statistically significant dose-dependent inhibitions of MCF7 cell proliferation from 35% to 95%. Annexin V-FITC and TUNEL assays showed positive staining for apoptosis of MCF7 cells treated with MEAD (15 mg and 25 mg for 48 h). Flow cytometric analyses of MCF7 cells with MEAD (15 mg/ml and 20 mg/ml) for 24 h demonstrated cell cycle arrest at 'S' phase; increased p53, Bax protein expression; caspase 3activation and decreased the mitochondrial membrane potential (MMP). Quantitative real time PCR (qRT-PCR) analysis showed up-regulation of p53, Bax, Fas, and FasL and down-regulation of Bcl-2. Conclusions MEAD inhibited MCF7 cells in vitro by the inducing cell cycle arrest and apoptosis. Our results indicate the anticancer effects of Ajwa dates, which therefore may be used as an adjunct therapy with conventional chemotherapeutics to achieve a synergistic effect against breast cancer. PMID:27441372

  19. A molecular understanding of D-homoestrone-induced G2/M cell cycle arrest in HeLa human cervical carcinoma cells.

    PubMed

    Minorics, Renáta; Bózsity, Noémi; Molnár, Judit; Wölfling, János; Mernyák, Erzsébet; Schneider, Gyula; Ocsovszki, Imre; Zupkó, István

    2015-10-01

    2-Methoxyestradiol (ME), one of the most widely investigated A-ring-modified metabolites of estrone, exerts significant anticancer activity on numerous cancer cell lines. Its pharmacological actions, including cell cycle arrest, microtubule disruption and pro-apoptotic activity, have already been described in detail. The currently tested D-ring-modified analogue of estrone, D-homoestrone, selectively inhibits cervical cancer cell proliferation and induces a G2/M phase cell cycle blockade, resulting in the development of apoptosis. The question arose of whether the difference in the chemical structures of these analogues can influence the mechanism of anticancer action. The aim of the present study was therefore to elucidate the molecular contributors of intracellular processes induced by D-homoestrone in HeLa cells. Apoptosis triggered by D-homoestrone develops through activation of the intrinsic pathway, as demonstrated by determination of the activities of caspase-8 and -9. It was revealed that D-homoestrone-treated HeLa cells are not able to enter mitosis because the cyclin-dependent kinase 1-cyclin B complex loses its activity, resulting in the decreased inactivation of stathmin and a concomitant disturbance of microtubule formation. However, unlike 2-ME, D-homoestrone does not exert a direct effect on tubulin polymerization. These results led to the conclusion that the D-homoestrone-triggered intracellular processes resulting in a cell cycle arrest and apoptosis in HeLa cells differ from those in the case of 2-ME. This may be regarded as an alternative mechanism of action among steroidal anticancer compounds.

  20. 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.

  1. Wogonoside induces growth inhibition and cell cycle arrest via promoting the expression and binding activity of GATA-1 in chronic myelogenous leukemia cells.

    PubMed

    Li, Hui; Hui, Hui; Xu, Jingyan; Yang, Hao; Zhang, Xiaoxiao; Liu, Xiao; Zhou, Yuxin; Li, Zhiyu; Guo, Qinglong; Lu, Na

    2016-06-01

    GATA-1, a zinc finger transcription factor, has been demonstrated to play a key role in the progression of leukemia. In this study, we investigate the effects of wogonoside, a naturally bioactive flavonoid derived from Scutellaria baicalensis Georgi, on cell growth and cell cycle in chronic myeloid leukemia (CML) cells, and uncover its underlying mechanisms. The experimental design comprised CML cell lines K562, imatinib-resistant K562 (K562r) cells, and primary CML cells, treated in vitro or in vivo, respectively, with wogonoside; growth and cell cycle were then evaluated. We found that wogonoside could induce growth inhibition and G0/G1 cell cycle arrest in both normal and K562r cells. Wogonoside promotes the expression of GATA-1 and facilitates the binding to methyl ethyl ketone (MEK) and p21 promoter, thus inhibiting MEK/extracellular signal-regulated kinase signaling and cell cycle checkpoint proteins, including CDK2, CDK4, cyclin A, and cyclin D1, and increasing p21 expression. Furthermore, in vivo studies showed that administration of wogonoside decreased CML cells and prolonged survival in NOD/SCID mice with CML cell xenografts. In conclusion, these results clearly revealed the inhibitory effect of wogonoside on the growth in CML cells and suggested that wogonoside may act as a promising drug for the treatment of imatinib-resistant CML.

  2. 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.

  3. Downregulation of telomerase activity by diclofenac and curcumin is associated with cell cycle arrest and induction of apoptosis in colon cancer.

    PubMed

    Rana, Chandan; Piplani, Honit; Vaish, Vivek; Nehru, Bimla; Sanyal, S N

    2015-08-01

    Uncontrolled cell proliferation is the hallmark of cancer, and cancer cells have typically acquired damage to genes that directly regulate their cell cycles. The synthesis of DNA onto the end of chromosome during the replicative phase of cell cycle by telomerase may be necessary for unlimited proliferation of cells. Telomerase, a ribonucleoprotein enzyme is considered as a universal therapeutic target of cancer because of its preferential expression in cancer cells and its presence in 90 % of tumors. We studied the regulation of telomerase and telomerase reverse transcriptase catalytic subunit (TERT) by diclofenac and curcumin, alone and also in combination, in 1, 2-dimethylhydrazine dihydrochloride-induced colorectal cancer in rats. The relationship of telomerase activity with tumors suppressor proteins (p51, Rb, p21), cell cycle machinery, and apoptosis was also studied. Telomerase is highly expressed in DMH group and its high activity is associated with increased TERT expression. However, telomerase is absent or is present at lower levels in normal tissue. CDK4, CDK2, cyclin D1, and cyclin E are highly expressed in DMH as assessed by RT-PCR, qRT-PCR, Western blot, and immunofluorescence analysis. Diclofenac and curcumin overcome these carcinogenic effects by downregulating telomerase activity, diminishing the expression of TERT, CDK4, CDK2, cyclin D1, and cyclin E. The anticarcinogenic effects shown after the inhibition of telomerase activity by diclofenac and curcumin may be associated with upregulation of tumor suppressor proteins p51, Rb, and p21, whose activation induces the cells cycle arrest and apoptosis.

  4. Silencing of TBX20 gene expression in rat myocardial and human embryonic kidney cells leads to cell cycle arrest in G2 phase

    PubMed Central

    Liu, Peiyan; Sun, Yueling; Qiu, Guangbin; Jiang, Hongkun; Qiu, Guangrong

    2016-01-01

    Congenital heart diseases (CHDs) are the most common birth defects due to abnormal cardiac development. The T-box 20 (TBX20) gene is a member of the T-box family of transcription factors and encodes TBX20, which is essential for early heart development. In the present study, reduced TBX20 expression was observed in CHD tissue samples compared with normal tissues, and the function of TBX20 in Rattus norvegicus myocardial cells [H9c2(2-1)] and human embryonic kidney cells (HEK293) was investigated. TBX20 was silenced in H9c2 and HEK293 cells via transfection of small interfering RNA and short hairpin RNA duplexes, respectively, and TBX20 mRNA and protein levels were subsequently examined using reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and western blot analysis. Cell proliferation was assessed using a cell counting kit and proliferating cell nuclear antigen expression was determined by western blotting. Analysis of cell apoptosis was achieved by annexin V-fluorescein isothiocyanate/propidium iodide staining and a fluorometric terminal deoxynucleotidyl transferase dUTP nick-end labeling system. Cell cycle analysis was achieved using fluorescence-activated cell sorting, and, an RT-qPCR array was used to profile the expression of TBX20-related genes. Silencing of TBX20 in H9c2 and HEK293 cells significantly inhibited cell proliferation, induced cell apoptosis and led to G2/M cell cycle arrest. A reduction in cyclin B1 mRNA levels and an increase in cyclin-dependent kinase inhibitor 1B mRNA levels was observed, which indicated that cells were arrested in G2 phase. Concurrently, the mRNA levels of GATA binding protein 4 were increased in both cell lines, which may provide an explanation for the abnormal cardiac hypertrophy observed in patients with congenital heart disease. These results suggest that TBX20 is required for heart morphogenesis, and inhibition of TBX20 expression may lead to the suppression of cell proliferation and cell cycle

  5. Cordycepin induces cell cycle arrest and apoptosis by inducing DNA damage and up-regulation of p53 in Leukemia cells

    PubMed Central

    Liao, Yuanhong; Ling, Jianya; Zhang, Guoying; Liu, Fengjun; Tao, Shengce; Han, Zeguang; Chen, Saijuan; Chen, Zhu; Le, Huangying

    2015-01-01

    Cordycepin, an adenosine analog derived from Cordyceps militaris has been shown to exert anti-tumor activity in many ways. However, the mechanisms by which cordycepin contributes to the anti-tumor still obscure. Here our present work showed that cordycepin inhibits cell growth in NB-4 and U937 cells by inducing apoptosis. Further study showed that cordycepin increases the expression of p53 which promotes the release of cytochrome c from mitochondria to the cytosol. The released cytochrome c can then activate caspase-9 and trigger intrinsic apoptosis. Cordycepin also blocks MAPK pathway by inhibiting the phosphorylation of ERK1/2, and thus sensitizes the apoptosis. In addition, our results showed that cordycepin inhibits the expression of cyclin A2, cyclin E, and CDK2, which leads to the accumulation of cells in S-phase. Moreover, our study showed that cordycepin induces DNA damage and causes degradation of Cdc25A, suggesting that cordycepin-induced S-phase arrest involves activation of Chk2-Cdc25A pathway. In conclusion, cordycepin-induced DNA damage initiates cell cycle arrest and apoptosis which leads to the growth inhibition of NB-4 and U937 cells. PMID:25590866

  6. Knockdown of Regulator of Cullins-1 (ROC1) Expression Induces Bladder Cancer Cell Cycle Arrest at the G2 Phase and Senescence

    PubMed Central

    Wang, Wei; Liu, Zhihong; Qu, Ping; Zhou, Zhengdong; Zeng, Yigang; Fan, Jie; Liu, Yong; Guo, Yifeng; Qiu, Jianxin

    2013-01-01

    Regulator of Cullins-1 (ROC1) is a key subunit in the Cullin-RING ligase (CRL) protein complex. Overexpression of ROC1 protein is associated with tumor progression and poor prognosis of non-muscle invasive bladder transitional cell carcinoma (NMIBC). This study was designed to assess the effects of ROC1 knockdown in bladder cancer cells and to determine the potential mechanisms involved. A total of 112 bladder cancer tissue specimens were recruited for immunohistochemical analyses of ROC1 overexpression. Bladder cancer cell lines were used to knockdown ROC1 expression using ROC1 siRNA. Our data showed that ROC1 knockdown remarkably inhibited bladder cancer cell growth, arrested cells at the G2 phase of the cell cycle, and induced the p53-dependent cell senescence. Molecularly, G2 arrest was associated with upregulation of p21, p27, cyclin B1, and Cdc2 proteins. ROC1 knockdown induced-senescence functioned through p53/p21 pathway. Knockdown of p21 expression partially rescued ROC1 knockdown-induced growth inhibition in cancer cells. Furthermore, nude mouse xenograft analyses confirmed these in vitro data. In conclusion, data from the current study indicate that ROC1 plays an essential role in bladder cancer progression and could serve as a novel anticancer target for bladder transitional cell carcinoma (BTCC). PMID:23667514

  7. The inhibition of PI3K and NFκB promoted curcumin-induced cell cycle arrest at G2/M via altering polyamine metabolism in Bcl-2 overexpressing MCF-7 breast cancer cells.

    PubMed

    Berrak, Özge; Akkoç, Yunus; Arısan, Elif Damla; Çoker-Gürkan, Ajda; Obakan-Yerlikaya, Pınar; Palavan-Ünsal, Narçin

    2016-02-01

    Bcl-2 protein has been contributed with number of genes which are involved in oncogenesis. Among the many targets of Bcl-2, NFκB have potential role in induction of cell cycle arrest. Curcumin has potential therapeutic effects against breast cancer through multiple signaling pathways. In this study, we investigated the role of curcumin in induction of cell cycle arrest via regulating of NFκB and polyamine biosynthesis in wt and Bcl-2+ MCF-7 cells. To examine the effect of curcumin on cell cycle regulatory proteins, PI3K/Akt, NFκB pathways and polyamine catabolism, we performed immunoblotting assay. In addition, cell cycle analysis was performed by flow cytometry. The results indicated that curcumin induced cell cycle arrest at G2/M phase by downregulation of cyclin B1 and Cdc2 and inhibited colony formation in MCF-7wt cells. However, Bcl-2 overexpression prevented the inhibition of cell cycle associated proteins after curcumin treatment. The combination of LY294002, PI3K inhibitor, and curcumin induced cell cycle arrest by decreasing CDK4, CDK2 and cyclin E2 in Bcl-2+ MCF-7 cells. Moreover, LY294002 further inhibited the phosphorylation of Akt in Bcl-2+ MCF-7 cells. Curcumin could suppress the nuclear transport of NFκB through decreasing the interaction of P-IκB-NFκB. The combination of wedelolactone, NFκB inhibitor, and curcumin acted different on SSAT expression in wt MCF-7 and Bcl-2+ MCF-7 cells. NFκB inhibition increased the SSAT after curcumin treatment in Bcl-2 overexpressed MCF-7 cells. Inhibition of NFκB activity as well as suppression of ROS generation with NAC resulted in the partial relief of cells from G2/M checkpoint after curcumin treatment in wt MCF-7 cells. In conclusion, the potential role of curcumin in induction of cell cycle arrest is related with NFκB-regulated polyamine biosynthesis.

  8. Silencing of MAP4K4 by short hairpin RNA suppresses proliferation, induces G1 cell cycle arrest and induces apoptosis in gastric cancer cells

    PubMed Central

    LIU, YUAN-FEI; QU, GUO-QIANG; LU, YUN-MIN; KONG, WU-MING; LIU, YUAN; CHEN, WEI-XIONG; LIAO, XIAO-HONG

    2016-01-01

    Gastric cancer (GC) is the second most common cause of cancer-associated mortality worldwide. Previous studies suggest that mitogen-activated protein kinase kinase kinase kinase isoform 4 (MAP4K4) is involved in cancer cell growth, apoptosis and migration. In the present study, bioinformatics analysis and reverse transcription-quantitative polymerase chain reaction were performed to determine if MAP4K4 was overexpressed in GC. The knockdown of MAP4K4 by RNA interference in GC cells markedly inhibited cell proliferation, which may be mediated by cell cycle arrest in the G1 phase. The silencing of MAP4K4 also induced cell apoptosis by increasing the ratio of Bax/Bcl-2. In addition, Notch signaling was markedly reduced by MAP4K4 silencing. The results of the present study suggested that inhibition of MAP4K4 may be a therapeutic strategy for GC. PMID:26549737

  9. Hydroxytyrosol and the Colonic Metabolites Derived from Virgin Olive Oil Intake Induce Cell Cycle Arrest and Apoptosis in Colon Cancer Cells.

    PubMed

    López de Las Hazas, Maria-Carmen; Piñol, Carme; Macià, Alba; Motilva, Maria-José

    2017-01-19

    After the sustained consumption of virgin olive oil (VOO), the unabsorbed native phenols (mainly hydroxytyrosol (HT)) are transformed into its catabolites in the intestine by microbials. The role of these catabolites in preventing colon cancer has not been sufficiently investigated. This work aims to study the antiproliferative and apoptotic activities in colon (Caco-2; HT-29) cancer cell lines of the main catabolites detected in human feces (phenylacetic, phenylpropionic, hydroxyphenylpropionic, and dihydroxyphenylpropionic acids and catechol), after the sustained VOO intake. Additionally, an assessment of the ability of these colonic cells to metabolize the studied compounds was performed. The results showed that HT and phenylacetic and hydroxyphenylpropionic acids produce cell cycle arrest and promote apoptosis. HT-29 cells were more sensitive to phenol treatments than Caco-2. In synthesis, the results of the present study represent a good starting point for understanding the potential apoptotic and antiproliferative effects of VOO phenolic compounds and their colonic metabolites.

  10. Monochloramine suppresses the proliferation of colorectal cancer cell line Caco-2 by both apoptosis and G2/M cell cycle arrest.

    PubMed

    Kohda, Tetsuya; Sakuma, Satoru; Abe, Muneyuki; Fujimoto, Yohko

    2014-03-01

    The aim of this study was to assess a possible role of monochloramine (NH2 Cl), one of the reactive chlorine species, which induce oxidative stress, on the proliferation of colorectal cancer cell line Caco-2. At concentrations ranging from 10 to 200 μM, NH2 Cl (14-61% inhibition), but not hypochlorous acid, dose-dependently inhibited the cell viability of Caco-2 cells. Experiments utilizing methionine (a scavenger of NH2 Cl), taurine-chloramine and glutamine-chloramine revealed that only NH2 Cl affects the cancer cell proliferation among reactive chlorine species, with a relative specificity. Furthermore, flow-cytometry experiments showed that the anti-proliferative effect of NH2 Cl is partially attributable to both apoptosis and G2/M cell cycle arrest. These results suggest that NH2 Cl has the potential to suppress colorectal cancer cell proliferation.

  11. Chinese Herbal Mixture, Tien-Hsien Liquid, Induces G2/M Cycle Arrest and Radiosensitivity in MCF-7 Human Breast Cancer Cells through Mechanisms Involving DNMT1 and Rad51 Downregulation

    PubMed Central

    Chow, Jyh-Ming; Yang, Chia-Ming; Kuo, Hui-Ching; Chang, Chia-Lun; Lee, Hsin-Lun; Lai, I-Chun; Chuang, Shuang-En

    2016-01-01

    The Chinese herbal mixture, Tien-Hsien Liquid (THL), has been proven to suppress the growth and invasiveness of cancer cells and is currently regarded as a complementary medicine for the treatment of cancer. Our previous study using acute promyelocytic leukemia cells uncovered its effect on the downregulation of DNA methyltransferase 1 (DNMT1) which is often overexpressed in cancer cells resulting in the repression of tumor suppressors via hypermethylation. Herein, we explored the effects of THL in MCF-7 breast cancer cells that also demonstrate elevated DNMT1. The results show that THL dose-dependently downregulated DNMT1 accompanied by the induction of tumor suppressors such as p21 and p15. THL arrested cell cycle in G2/M phase and decreased the protein levels of cyclin A, cyclin B1, phospho-pRb, and AKT. DNMT1 inhibition was previously reported to exert a radiosensitizing effect in cancer cells through the repression of DNA repair. We found that THL enhanced radiation-induced clonogenic cell death in MCF-7 cells and decreased the level of DNA double-strand break repair protein, Rad51. Our observations may be the result of DNMT1 downregulation. Due to the fact that DNMT1 inhibition is now a mainstream strategy for anticancer therapy, further clinical trials of THL to confirm its clinical efficacy are warranted. PMID:27525019

  12. Inducing G2/M Cell Cycle Arrest and Apoptosis through Generation Reactive Oxygen Species (ROS)-Mediated Mitochondria Pathway in HT-29 Cells by Dentatin (DEN) and Dentatin Incorporated in Hydroxypropyl-β-Cyclodextrin (DEN-HPβCD)

    PubMed Central

    Ashwaq, Al-Abboodi Shakir; Al-Qubaisi, Mothanna Sadiq; Rasedee, Abdullah; Abdul, Ahmad Bustamam; Taufiq-Yap, Yun Hin; Yeap, Swee Keong

    2016-01-01

    Dentatin (DEN), purified from the roots of Clausena excavata Burm f., has poor aqueous solubility that reduces its therapeutic application. The aim of this study was to assess the effects of DEN-HPβCD (hydroxypropyl-β-cyclodextrin) complex as an anticancer agent in HT29 cancer cell line and compare with a crystal DEN in dimethyl sulfoxide (DMSO). The exposure of the cancer cells to DEN or DEN-HPβCD complex leads to cell growth inhibition as determined by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. To analyze the mechanism, in which DEN or DEN-HPβCD complex causes the death in human colon HT29 cancer cells, was evaluated by the enzyme-linked immunosorbent assay (ELIZA)-based assays for caspase-3, 8, 9, and reactive oxygen species (ROS). The findings showed that an anti-proliferative effect of DEN or DEN-HPβCD complex were via cell cycle arrest at the G2/M phase and eventually induced apoptosis through both mitochondrial and extrinsic pathways. The down-regulation of poly(ADP-ribose) polymerase (PARP) which leaded to apoptosis upon treatment, was investigated by Western-blotting. Hence, complexation between DEN and HPβCD did not diminish or eliminate the effective properties of DEN as anticancer agent. Therefore, it would be possible to resolve the conventional and current issues associated with the development and commercialization of antineoplastic agents in the future. PMID:27763535

  13. The novel, orally bioavailable HSP90 inhibitor NVP-HSP990 induces cell cycle arrest and apoptosis in multiple myeloma cells and acts synergistically with melphalan by increased cleavage of caspases.

    PubMed

    Lamottke, Britta; Kaiser, Martin; Mieth, Maren; Heider, Ulrike; Gao, Zhenhai; Nikolova, Zariana; Jensen, Michael R; Sterz, Jan; von Metzler, Ivana; Sezer, Orhan

    2012-05-01

    Heat shock protein 90 (HSP90) binds and stabilizes numerous proteins and kinases essential for myeloma cell survival and proliferation. We and others have recently demonstrated that inhibition of HSP90 by small molecular mass inhibitors induces cell death in multiple myeloma (MM). However, some of the HSP90 inhibitors involved in early clinical trials have shown limited antitumor activity and unfavorable toxicity profiles. Here, we analyzed the effects of the novel, orally bioavailable HSP90 inhibitor NVP-HSP990 on MM cell proliferation and survival. The inhibitor led to a significant reduction in myeloma cell viability and induced G2 cell cycle arrest, degradation of caspase-8 and caspase-3, and induction of apoptosis. Inhibition of the HSP90 ATPase activity was accompanied by the degradation of MM phospho-Akt and phospho-ERK1/2 and upregulation of Hsp70. Exposure of MM cells to a combination of NVP-HSP990 and either melphalan or histone deacetylase (HDAC) inhibitors caused synergistic inhibition of viability, increased induction of apoptosis, and was able to overcome the primary resistance of the cell line RPMI-8226 to HSP90 inhibition. Combined incubation with melphalan and NVP-HSP990 led to synergistically increased cleavage of caspase-2, caspase-9, and caspase-3. These data demonstrate promising activity for NVP-HSP990 as single agent or combination treatment in MM and provide a rationale for clinical trials.

  14. A constitutively active epidermal growth factor receptor cooperates with disruption of G1 cell-cycle arrest pathways to induce glioma-like lesions in mice

    PubMed Central

    Holland, Eric C.; Hively, Wendy P.; DePinho, Ronald A.; Varmus, Harold E.

    1998-01-01

    The epidermal growth factor receptor (EGFR) gene is amplified or mutated in 30%–50% of human gliobastoma multiforme (GBM). These mutations are associated usually with deletions of the INK4a–ARF locus, which encodes two gene products (p16INK4a and p19ARF) involved in cell-cycle arrest and apoptosis. We have investigated the role of EGFR mutation in gliomagenesis, using avian retroviral vectors to transfer a mutant EGFR gene to glial precursors and astrocytes in transgenic mice expressing tv-a, a gene encoding the retrovirus receptor. TVA, under control of brain cell type-specific promoters. We demonstrate that expression of a constitutively active, mutant form of EGFR in cells in the glial lineage can induce lesions with many similarities to human gliomas. These lesions occur more frequently with gene transfer to mice expressing tv-a from the progenitor-specific nestin promoter than to mice expressing tv-a from the astrocyte-specific glial fibrillary acidic protein (GFAP) promoter, suggesting that tumors arise more efficiently from immature cells in the glial lineage. Furthermore, EGFR-induced gliomagenesis appears to require additional mutations in genes encoding proteins involved in cell-cycle arrest pathways. We have produced these combinations by simultaneously infecting tv-a transgenic mice with vectors carrying cdk4 and EGFR or by infecting tv-a transgenic mice bearing a disrupted INK4a–ARF locus with the EGFR-carrying vector alone. Moreover, EGFR-induced gliomagenesis does not occur in conjunction with p53 deficiency, unless the mice are also infected with a vector carrying cdk4. The gliomagenic combinations of genetic lesions required in mice are similar to those found in human gliomas. PMID:9851974

  15. Combination of lentivirus-mediated silencing of PPM1D and temozolomide chemotherapy eradicates malignant glioma through cell apoptosis and cell cycle arrest

    PubMed Central

    Wang, Peng; Ye, Jing-An; Hou, Chong-Xian; Zhou, Dong; Zhan, Sheng-Quan

    2016-01-01

    Temozolomide (TMZ) is approved for use as first-line treatment for glioblastoma multiforme (GBM). However, GBM shows chemoresistance shortly after the initiation of treatment. In order to detect whether silencing of human protein phosphatase 1D magnesium dependent (PPM1D) gene could increase the effects of TMZ in glioma cells, glioma cells U87-MG were infected with lentiviral shRNA vector targeting PPM1D silencing. After PPM1D silencing was established, cells were treated with TMZ. The multiple functions of human glioma cells after PPM1D silencing and TMZ chemotherapy were detected by flow cytometry and MTT assay. Significantly differentially expressed genes were distinguished by microarray-based gene expression profiling and analyzed by gene pathway enrichment analysis and ontology assessment. Western blotting was used to establish the protein expression of the core genes. PPM1D gene silencing improves TMZ induced cell proliferation and induces cell apoptosis and cell cycle arrest. When PPM1D gene silencing combined with TMZ was performed in glioma cells, 367 genes were upregulated and 444 genes were downregulated compared with negative control. The most significant differential expression pathway was pathway in cancer and IGFR1R, PIK3R1, MAPK8 and EP300 are core genes in the network. Western blotting showed that MAPK8 and PIK3R1 protein expression levels were upregulated and RB1 protein expression was decreased. It was consistent with that detected in gene expression profiling. In conclusion, PPM1D gene silencing combined with TMZ eradicates glioma cells through cell apoptosis and cell cycle arrest. PIK3R1/AKT pathway plays a role in the multiple functions of glioma cells after PPM1D silencing and TMZ chemotherapy. PMID:27633132

  16. Involvement of Ganglioside GM3 in G2/M Cell Cycle Arrest of Human Monocytic Cells Induced by Actinobacillus actinomycetemcomitans Cytolethal Distending Toxin

    PubMed Central

    Mise, Koji; Akifusa, Sumio; Watarai, Shinobu; Ansai, Toshihiro; Nishihara, Tatsuji; Takehara, Tadamichi

    2005-01-01

    Actinobacillus actinomycetemcomitans produces a toxin called cytolethal distending toxin (CDT), which causes host cell DNA damage leading to the induction of DNA damage checkpoint pathways. CDT consists of three subunits, CdtA, CdtB, and CdtC. CdtB is the active subunit of CDT and exerts its effect as a nuclease that damages nuclear DNA, triggering cell cycle arrest. In the present study, we confirmed that the only combination of toxin proteins causing cell cycle arrest was that of all three recombinant CDT (rCDT) protein subunits. Furthermore, in order for rCDT to demonstrate toxicity, it was necessary for CdtA and CdtC to access the cell before CdtB. The coexistence of CdtA and CdtC was necessary for these subunits to bind to the cell. Cells treated with the glucosylceramide synthesis inhibitor 1-phenyl-2-palmitoylamino-3-morpholino-1-propanol showed resistance to the cytotoxicity induced by rCDT. Furthermore, LY-B cells, which are deficient in the biosynthesis of sphingolipid, also showed resistance to the cytotoxicity induced by rCDT. To evaluate the binding of each subunit for glucosylceramides, we performed thin-layer chromatography immunostaining. The results indicated that each subunit reacted with the glycosphingolipids GM1, GM2, GM3, Gb3, and Gb4. The rCDT mixture incubated with liposomes containing GM3 displayed partially reduced toxicity. These results indicate that GM3 can act as a CDT receptor. PMID:16040998

  17. 1-(2-Hydroxy-5-methylphenyl)-3-phenyl-1,3-propanedione Induces G1 Cell Cycle Arrest and Autophagy in HeLa Cervical Cancer Cells

    PubMed Central

    Tsai, Jie-Heng; Hsu, Li-Sung; Huang, Hsiu-Chen; Lin, Chih-Li; Pan, Min-Hsiung; Hong, Hui-Mei; Chen, Wei-Jen

    2016-01-01

    The natural agent, 1-(2-hydroxy-5-methylphenyl)-3-phenyl-1,3-propanedione (HMDB), has been reported to have growth inhibitory effects on several human cancer cells. However, the role of HMDB in cervical cancer remains unclear. Herein, we found that HMDB dose- and time-dependently inhibited growth of HeLa cervical cancer cells, accompanied with G1 cell cycle arrest. HMDB decreased protein expression of cyclins D1/D3/E and cyclin-dependent kinases (CDKs) 2/4/6 and reciprocally increased mRNA and protein levels of CDK inhibitors (p15, p16, p21, and p27), thereby leading to the accumulation of hypophosphorylated retinoblastoma (Rb) protein. HMDB also triggered the accumulation of acidic vesicles and formation of microtubule-associated protein-light chain 3 (LC3), followed by increased expression of LC3 and Beclin-1 and decreased expression of p62, suggesting that HMDB triggered autophagy in HeLa cells. Meanwhile, suppression of the expression of survivin and Bcl-2 implied that HMDB-induced autophagy is tightly linked to apoptosis. Exploring the action mechanism, HMDB induced autophagy via the modulation of AMP-activated protein kinase (AMPK) and mTOR signaling pathway rather than the class III phosphatidylinositol 3-kinase pathway. These results suggest that HMDB inhibits HeLa cell growth by eliciting a G1 arrest through modulation of G1 cell cycle regulators and by concomitantly inducing autophagy through the mediation of AMPK-mTOR and Akt-mTOR pathways, and may be a promising antitumor agent against cervical cancer. PMID:27527160

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

    PubMed

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

    2015-05-01

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

  19. DNA damage-induced S and G2/M cell cycle arrest requires mTORC2-dependent regulation of Chk1.

    PubMed

    Selvarajah, Jogitha; Elia, Androulla; Carroll, Veronica A; Moumen, Abdeladim

    2015-01-01

    mTOR signalling is commonly dysregulated in cancer. Concordantly, mTOR inhibitors have demonstrated efficacy in a subset of tumors and are in clinical trials as combination therapies. Although mTOR is associated with promoting cell survival after DNA damage, the exact mechanisms are not well understood. Moreover, since mTOR exists as two complexes, mTORC1 and mTORC2, the role of mTORC2 in cancer and in the DNA damage response is less well explored. Here, we report that mTOR protein levels and kinase activity are transiently increased by DNA damage in an ATM and ATR-dependent manner. We show that inactivation of mTOR with siRNA or pharmacological inhibition of mTORC1/2 kinase prevents etoposide-induced S and G2/M cell cycle arrest. Further results show that Chk1, a key regulator of the cell cycle arrest, is important for this since ablation of mTOR prevents DNA damage-induced Chk1 phosphorylation and decreases Chk1 protein production. Furthermore, mTORC2 was essential and mTORC1 dispensable, for this role. Importantly, we show that mTORC1/2 inhibition sensitizes breast cancer cells to chemotherapy. Taken together, these results suggest that breast cancer cells may rely on mTORC2-Chk1 pathway for survival and provide evidence that mTOR kinase inhibitors may overcome resistance to DNA-damage based therapies in breast cancer.

  20. Downregulation of LAPTM5 suppresses cell proliferation and viability inducing cell cycle arrest at G0/G1 phase of bladder cancer cells.

    PubMed

    Chen, Liang; Wang, Gang; Luo, Yi; Wang, Yongzhi; Xie, Conghua; Jiang, Wei; Xiao, Yu; Qian, Guofeng; Wang, Xinghuan

    2017-01-01

    Our transcriptome analysis revealed in bladder cancer (BCa) tissues a significant induction of lysosomal-associated multispanning membrane protein 5 (LAPTM5), a lysosomal membrane protein preferentially expressing in immune cells and hematopoietic cells. Transportation of LAPTM5 from Golgi to lysosome could be inhibited by deficiency of Nedd4, a key member of E3 ubiquitin ligase family overexpressing in invasive BCa and promoting its progression. Therefore, we hypothesize that LAPTM5 may be closely correlated with BCa tumorigenesis. In human BCa tissues, we observed that LAPTM5 was significantly induced at both mRNA and protein levels, which is consistent with our microarray result. Furthermore, we established a BCa cell model with downregulated LAPTM5, revealing a significantly delayed growth rate in the BCa cells with knockdown of LAPTM5. Moreover, cell cycle arrest at G0/G1 phase was triggered by decreased LAPTM5 as well, which could lead to delayed BCa cell growth. In contrast, no significant alteration of apoptosis in the BCa cells with downregulated LAPTM5 was noticed. Analysis of the changes of migration and invasion, showed significant reduced LAPTM5 suppressed cell metastasis. Furthermore, proteins involved in epithelial-mesenchymal transition (EMT) were strongly altered, which plays a central role in metastasis. In addition, phosphorylated ERK1/2 and p38, key members of mitogen-activated protein kinase (MAPK) family regulating BCa tumorigenesis, were strongly decreased. Taken together, our results suggested that decreased LAPTM5 inhibited proliferation and viability, as well as induced G0/G1 cell cycle arrest possibly via deactivation of ERK1/2 and p38 in BCa cells.

  1. The vicious cycle of apoptotic beta-cell death in type 1 diabetes.

    PubMed

    Kaminitz, Ayelet; Stein, Jerry; Yaniv, Isaac; Askenasy, Nadir

    2007-01-01

    Autoimmune insulitis, the cause of type 1 diabetes, evolves through several discrete stages that culminate in beta-cell death. In the first stage, antigenic epitopes of B-cell-specific peptides are processed by antigen presenting cells in local lymph nodes, and auto-reactive lymphocyte clones are propagated. Subsequently, cell-mediated and direct cytokine-mediated reactions are generated against the beta-cells, and the beta-cells are sensitized to apoptosis. Ironically, the beta-cells themselves contribute some of the cytokines and chemokines that provoke the immune reaction within the islets. Once this vicious cycle of autoimmunity is fully developed, the fate of the beta-cells in the islets is sealed, and clinical diabetes inevitably ensues. Differences in various aspects of these concurrent events appear to underlie the significant discrepancies in experimental data observed in experimental models that simulate autoimmune insulitis.

  2. Cross talk between cell death and cell cycle progression: BCL-2 regulates NFAT-mediated activation.

    PubMed Central

    Linette, G P; Li, Y; Roth, K; Korsmeyer, S J

    1996-01-01

    BCL-2-deficient T cells demonstrate accelerated cell cycle progression and increased apoptosis following activation. Increasing the levels of BCL-2 retarded the G0-->S transition, sustained the levels of cyclin-dependent kinase inhibitor p27Kip1, and repressed postactivation death. Proximal signal transduction events and immediate early gene transcription were unaffected. However, the transcription and synthesis of interleukin 2 and other delayed early cytokines were markedly attenuated by BCL-2. In contrast, a cysteine protease inhibitor that also blocks apoptosis had no substantial affect upon cytokine production. InterleUkin 2 expression requires several transcription factors of which nuclear translocation of NFAT (nuclear factor of activated T cells) and NFAT-mediated transactivation were impaired by BCL-2. Thus, select genetic aberrations in the apoptotic pathway reveal a cell autonomous coregulation of activation. Images Fig. 3 Fig. 4 Fig. 7 PMID:8790367

  3. Ethyl acetate fraction of Garcina epunctata induces apoptosis in human promyelocytic cells (HL-60) through the ROS generation and G0/G1 cell cycle arrest: a bioassay-guided approach.

    PubMed

    Constant Anatole, Pieme; Guru, Santoh Kumar; Bathelemy, Ngamegni; Jeanne, Ngogang; Bhushan, Shashi; Murayama, Tetsuya; Saxena, Ajit Kumar

    2013-11-01

    Number of deaths due to cancer diseases is increasing in the world. There is an urgent need to develop alternative therapeutic measures against the disease. Our study reports the cytotoxicity activity of Garcina epunctata (gutifferae) in human promyelocytic leukemia cells (HL-60) and prostate cancer cells (PC-3) was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT). Changes in mitochondrial membrane potential (MMP), reactive oxygen species (ROS) and morphological changes associated with apoptosis were examined by flow cytometry and Hoescht staining respectively. The results of in vitro antiproliferative screening of fractions and extract from G. epunctata indicated that three fractions inhibited the viability of PC-3 cells with IC₅₀ varied from 50 to 88 μ/ml while two fractions inhibited the proliferation of HL-60 cells with IC₅₀ range between 47.5 and 12 μg/ml. Among the entire fraction tested, Hex-EtOAc (75:25) showed cytotoxic effects on the two cell lines and EtOAc fraction was most active only HL-60 cells (12 μg/ml). Treatment of HL-60 cells with G. epunctata (20, 50, 100 μg/ml) for 24 h led to a significant dose-dependent increase in the percentage of cells in sub-G1 phase by analysis of the content of DNA in cells, and a number of apoptotic bodies containing nuclear fragments were observed in cells treated with 100 μg/ml. The EtOAc fraction of G. epunctata treatment significantly arrested HL-60 cells at the G0/G1 phase (p<0.05) and ROS was significantly elevated as well as the loss of membrane mitochondrial potential in a concentration dependant manner. The results demonstrated that the EtOAc fraction of G. epunctata inhibited the proliferation of HL-60 cells, leading to cell cycle arrest and programmed cell death, which was confirmed to occur through the mitochondrial pathway.

  4. Cinnamomum cassia essential oil and its major constituent cinnamaldehyde induced cell cycle arrest and apoptosis in human oral squamous cell carcinoma HSC-3 cells.

    PubMed

    Chang, Wen-Lun; Cheng, Fu-Chou; Wang, Shu-Ping; Chou, Su-Tze; Shih, Ying

    2017-02-01

    Cinnamomum cassia essential oil (CC-EO) has various functional properties, such as anti-microbial, hypouricemic, anti-tyrosinase and anti-melanogenesis activities. The present study aimed to evaluate the anti-cancer activities of CC-EO and its major constituent, cinnamaldehyde, in human oral squamous cell carcinoma HSC-3 cells. Determination of the cell viability, apoptotic characteristics, DNA damage, cell cycle analysis, reactive oxygen species (ROS) production, mitochondrial membrane potential, cytosolic Ca(2+) level and intracellular redox status were performed. Our results demonstrated that CC-EO and cinnamaldehyde significantly decreased cell viability and caused morphological changes. The cell cycle analysis revealed that CC-EO and cinnamaldehyde induced G2/M cell cycle arrest in HSC-3 cells. The apoptotic characteristics (DNA laddering and chromatin condensation) and DNA damage were observed in the CC-EO-treated and cinnamaldehyde-treated HSC-3 cells. Moreover, CC-EO and cinnamaldehyde promoted an increase in cytosolic Ca(2+) levels, induced mitochondrial dysfunction and activated cytochrome c release. The results of ROS production and intracellular redox status demonstrated that CC-EO and cinnamaldehyde significantly increased the ROS production and thiobarbituric acid reactive substance levels, and the cellular glutathione content and glutathione peroxidase activity were significantly reduced in HSC-3 cells. Our results suggest that CC-EO and cinnamaldehyde may possess anti-oral cancer activity in HSC-3 cells. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 456-468, 2017.

  5. The long non-coding RNA HOTAIR promotes the proliferation of serous ovarian cancer cells through the regulation of cell cycle arrest and apoptosis

    SciTech Connect

    Qiu, Jun-jun; Wang, Yan; Ding, Jing-xin; Jin, Hong-yan; Yang, Gong; Hua, Ke-qin

    2015-05-01

    HOX transcript antisense RNA (HOTAIR) is a well-known long non-coding RNA (lncRNA) whose dysregulation correlates with poor prognosis and malignant progression in many forms of cancer. Here, we investigate the expression pattern, clinical significance, and biological function of HOTAIR in serous ovarian cancer (SOC). Clinically, we found that HOTAIR levels were overexpressed in SOC tissues compared with normal controls and that HOTAIR overexpression was correlated with an advanced FIGO stage and a high histological grade. Multivariate analysis revealed that HOTAIR is an independent prognostic factor for predicting overall survival in SOC patients. We demonstrated that HOTAIR silencing inhibited A2780 and OVCA429 SOC cell proliferation in vitro and that the anti-proliferative effects of HOTAIR silencing also occurred in vivo. Further investigation into the mechanisms responsible for the growth inhibitory effects by HOTAIR silencing revealed that its knockdown resulted in the induction of cell cycle arrest and apoptosis through certain cell cycle-related and apoptosis-related proteins. Together, these results highlight a critical role of HOTAIR in SOC cell proliferation and contribute to a better understanding of the importance of dysregulated lncRNAs in SOC progression. - Highlights: • HOTAIR overexpression correlates with an aggressive tumour phenotype and a poor prognosis in SOC. • HOTAIR promotes SOC cell proliferation both in vitro and in vivo. • The proliferative role of HOTAIR is associated with regulation of the cell cycle and apoptosis.

  6. Mitotic Stress Is an Integral Part of the Oncogene-Induced Senescence Program that Promotes Multinucleation and Cell Cycle Arrest

    PubMed Central

    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.

    2015-01-01

    Summary 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

  7. 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.

  8. 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.

  9. Double stranded-RNA-mediated activation of P21 gene induced apoptosis and cell cycle arrest in renal cell carcinoma

    PubMed Central

    Whitson, Jared M; Noonan, Emily J; Pookot, Deepa; Place, Robert F; Dahiya, Rajvir

    2014-01-01

    Small double stranded RNAs (dsRNA) are a new class of molecules which regulate gene expression. Accumulating data suggest that some dsRNA can function as tumor suppressors. Here we report further evidence on the potential of dsRNA mediated p21 induction. Using the human renal cell carcinoma cell line A498, we found that dsRNA targeting the p21 promoter significantly induced the expression of p21 mRNA and protein levels. As a result, dsP21 transfected cells had a significant decrease in cell viability with a concomitant G1 arrest. We also observed a significant increase in apoptosis. These findings were associated with a significant decrease in survivin mRNA and protein levels. This is the first report that demonstrates dsRNA mediated gene activation in renal cell carcinoma and suggests that forced over-expression of p21 may lead to an increase in apoptosis through a survivin dependent mechanism. PMID:19384944

  10. Double stranded-RNA-mediated activation of P21 gene induced apoptosis and cell cycle arrest in renal cell carcinoma.

    PubMed

    Whitson, Jared M; Noonan, Emily J; Pookot, Deepa; Place, Robert F; Dahiya, Rajvir

    2009-07-15

    Small double stranded RNAs (dsRNA) are a new class of molecules which regulate gene expression. Accumulating data suggest that some dsRNA can function as tumor suppressors. Here, we report further evidence on the potential of dsRNA mediated p21 induction. Using the human renal cell carcinoma cell line A498, we found that dsRNA targeting the p21 promoter significantly induced the expression of p21 mRNA and protein levels. As a result, dsP21 transfected cells had a significant decrease in cell viability with a concomitant G1 arrest. We also observed a significant increase in apoptosis. These findings were associated with a significant decrease in survivin mRNA and protein levels. This is the first report that demonstrates dsRNA mediated gene activation in renal cell carcinoma and suggests that forced over-expression of p21 may lead to an increase in apoptosis through a survivin dependent mechanism.

  11. Cell cycle arrest and apoptosis induced by 1α,25(OH)2D3 and TX 527 in Kaposi sarcoma is VDR dependent.

    PubMed

    González-Pardo, Verónica; Suares, Alejandra; Verstuyf, Annemieke; De Clercq, Pierre; Boland, Ricardo; de Boland, Ana Russo

    2014-10-01

    We have previously shown that 1α,25(OH)2-Vitamin D3 [1α,25(OH)2D3] and its less calcemic analog TX 527 inhibit the proliferation of endothelial cells transformed by the viral G protein-coupled receptor associated to Kaposi sarcoma (vGPCR) and this could be partially explained by the inhibition of the NF-κB pathway. In this work, we further explored the mechanism of action of both vitamin D compounds in Kaposi sarcoma. We investigated whether the cell cycle arrest and subsequent apoptosis of endothelial cells (SVEC) and SVEC transformed by vGPCR (SVEC-vGPCR) elicited by 1α,25(OH)2D3 and TX 527 were mediated by the vitamin D receptor (VDR). Cell cycle analysis of SVEC and SVEC-vGPCR treated with 1α,25(OH)2D3 (10nM, 48h) revealed that 1α,25(OH)2D3 increased the percentage of cells in the G0/G1 phase and diminished the percentage of cells in the S phase of the cell cycle. Moreover, the number of cells in the S phase was higher in SVEC-vGPCR than in SVEC due to vGPCR expression. TX 527 exerted similar effects on growth arrest in SVEC-vGPCR cells. The cell cycle changes were suppressed when the expression of the VDR was blocked by a stable transfection of shRNA against VDR. Annexin V-PI staining demonstrated apoptosis in both SVEC and SVEC-vGPCR after 1α,25(OH)2D3 and TX 527 treatment (10nM, 24h). Cleavage of caspase-3 detected by Western blot analysis was increased to a greater extent in SVEC than in SVEC-vGPCR cells, and this effect was also blocked in VDR knockdown cells. Altogether, these results suggest that 1α,25(OH)2D3 and TX 527 inhibit the proliferation of SVEC and SVEC-vGPCR and induce apoptosis by a mechanism that involves the VDR.

  12. Regulation of cell division cycle progression by bcl-2 expression: a potential mechanism for inhibition of programmed cell death

    PubMed Central

    1996-01-01

    Expression of the bcl-2 gene has been shown to effectively confer resistance to programmed cell death under a variety of circumstances. However, despite a wealth of literature describing this phenomenon, very little is known about the mechanism of resistance. In the experiments described here, we show that bcl-2 gene expression can result in an inhibition of cell division cycle progression. These findings are based upon the analysis of cell cycle distribution, cell cycle kinetics, and relative phosphorylation of the retinoblastoma tumor suppressor protein, using primary tissues in vivo, ex vivo, and in vitro, as well as continuous cell lines. The effects of bcl-2 expression on cell cycle progression appear to be focused at the G1 to S phase transition, which is a critical control point in the decision between continued cell cycle progression or the induction programmed cell death. In all systems tested, bcl-2 expression resulted in a substantial 30-60% increase in the length of G1 phase; such an increase is very substantial in the context of other regulators of cell cycle progression. Based upon our findings, and the related findings of others, we propose a mechanism by which bcl-2 expression might exert its well known inhibition of programmed cell death by regulating the kinetics of cell cycle progression at a critical control point. PMID:8642331

  13. The DR6 protein from human herpesvirus-6B induces p53-independent cell cycle arrest in G{sub 2}/M

    SciTech Connect

    Schleimann, Mariane H.; Hoberg, Søren; Solhøj Hansen, Aida; Bundgaard, Bettina; Witt, Christoffer T.; Kofod-Olsen, Emil; Höllsberg, Per

    2014-03-15

    HHV-6B infection inhibits cell proliferation in G{sub 2}/M, but no protein has so far been recognized to exert this function. Here we identify the protein product of direct repeat 6, DR6, as an inhibitor of G{sub 2}/M cell-cycle progression. Transfection of DR6 reduced the total number of cells compared with mock-transfected cells. Lentiviral transduction of DR6 inhibited host cell DNA synthesis in a p53-independent manner, and this inhibition was DR6 dose-dependent. A deletion of 66 amino acids from the N-terminal part of DR6 prevented efficient nuclear translocation and the ability to inhibit DNA synthesis. DR6-induced accumulation of cells in G{sub 2}/M was accompanied by an enhanced expression of cyclin B1 that accumulated predominantly in the cytoplasm. Pull-down of cyclin B1 brought down pCdk1 with the inactivating phosphorylation at Tyr15. Together, DR6 delays cell cycle with an accumulation of cells in G{sub 2}/M and thus might be involved in HHV-6B-induced cell-cycle arrest. - Highlights: • HHV-6B-encoded DR6 protein inhibits cell proliferation. • DR6 inhibits host cell DNA synthesis independent of p53. • DR6 delays the cell cycle in G{sub 2}/M. • An N-terminal sequence is necessary for DR6 function. • DR6 induces cytoplasmic accumulation of cyclin B1.

  14. Effects of 5,6-Dihydroxy-2,4-Dimethoxy-9,10-Dihydrophenanthrene on G2/M Cell Cycle Arrest and Apoptosis in Human Lung Carcinoma Cells.

    PubMed

    Duangprompo, Wipada; Aree, Kalaya; Itharat, Arunporn; Hansakul, Pintusorn

    2016-01-01

    5,6-dihydroxy-2,4-dimethoxy-9,10-dihydrophenanthrene (HMP) is an active compound isolated from the rhizome extracts of Dioscorea membranacea Pierre, a Thai medicinal plant. This study aimed to investigate the growth-inhibitory and apoptosis-inducing effects of HMP in human lung cancer A549 cells. The antiproliferative and cytotoxic effects of HMP were analyzed by a Sulforhodamine B assay. Cell division, cell cycle distribution and membrane asymmetry changes were each performed with different fluorescent dyes and then analyzed by flow cytometry. Real-time PCR and immunoblotting were used to detect cell cycle- and apoptosis-related mRNA levels and proteins, respectively. The nuclear morphology of the cells stained with DAPI and DNA fragmentation were detected by fluorescence microscopy and gel electrophoresis, respectively. The results showed that HMP exerted strong antiproliferative and cytotoxic activities in A549 cells with the highest selectivity index. It halted the cell cycle in [Formula: see text]/M phase via down-regulation of the expression levels of regulatory proteins Cdc25C, Cdk1 and cyclinB1. In addition, HMP induced early apoptotic cells with externalized phosphatidylserine and subsequent apoptotic cells in sub-[Formula: see text] phase. HMP increased caspase-3 activity and levels of the cleaved (active) form of caspase-3 whose actions were supported by the cleavage of its target PARP, nuclear condensation and DNA apoptotic ladder. Moreover, HMP significantly increased the mRNA and protein levels of proapoptotic Bax as well as promoted subsequent caspase-9 activation and BID cleavage, indicating HMP-induced apoptosis via both intrinsic and extrinsic pathways. These data support, for the first time, the potential role of HMP as a cell-cycle arrest and apoptosis-inducing agent for lung cancer treatment.

  15. Novel Pactamycin Analogs Induce p53 Dependent Cell-Cycle Arrest at S-Phase in Human Head and Neck Squamous Cell Carcinoma (HNSCC) Cells

    PubMed Central

    Guha, Gunjan; Liang, Xiaobo; Kulesz-Martin, Molly F.; Mahmud, Taifo; Indra, Arup Kumar; Ganguli-Indra, Gitali

    2015-01-01

    Pactamycin, although putatively touted as a potent antitumor agent, has never been used as an anticancer drug due to its high cytotoxicity. In this study, we characterized the effects of two novel biosynthetically engineered analogs of pactamycin, de-6MSA-7-demethyl-7-deoxypactamycin (TM-025) and 7-demethyl-7-deoxypactamycin (TM-026), in head and neck squamous cell carcinoma (HNSCC) cell lines SCC25 and SCC104. Both TM-025 and TM-026 exert growth inhibitory effects on HNSCC cells by inhibiting cell proliferation. Interestingly, unlike their parent compound pactamycin, the analogs do not inhibit synthesis of nascent protein in a cell-based assay. Furthermore, they do not induce apoptosis or autophagy in a dose- or a time-dependent manner, but induce mild senescence in the tested cell lines. Cell cycle analysis demonstrated that both analogs significantly induce cell cycle arrest of the HNSCC cells at S-phase resulting in reduced accumulation of G2/M-phase cells. The pactamycin analogs induce expression of cell cycle regulatory proteins including master regulator p53, its downstream target p21Cip1/WAF1, p27kip21, p19, cyclin E, total and phospho Cdc2 (Tyr15) and Cdc25C. Besides, the analogs mildly reduce cyclin D1 expression without affecting expression of cyclin B, Cdk2 and Cdk4. Specific inhibition of p53 by pifithrin-α reduces the percentage of cells accumulated in S-phase, suggesting contribution of p53 to S-phase increase. Altogether, our results demonstrate that Pactamycin analogs TM-025 and TM-026 induce senescence and inhibit proliferation of HNSCC cells via accumulation in S-phase through possible contribution of p53. The two PCT analogs can be widely used as research tools for cell cycle inhibition studies in proliferating cancer cells with specific mechanisms of action. PMID:25938491

  16. Anticancer and apoptotic activities of oleanolic acid are mediated through cell cycle arrest and disruption of mitochondrial membrane potential in HepG2 human hepatocellular carcinoma cells

    PubMed Central

    ZHU, YUE-YONG; HUANG, HONG-YAN; WU, YIN-LIAN

    2015-01-01

    Hepatocellular carcinoma (HCC) is an aggressive form of cancer, with high rates of morbidity and mortality, a poor prognosis and limited therapeutic options. The objective of the present study was to demonstrate the anticancer activity of oleanolic acid in HepG2 human HCC cells. Cell viability was evaluated using an MTT assay, following administration of various doses of oleanolic acid. The effect of oleanolic acid on cell cycle phase distribution and mitochondrial membrane potential was evaluated using flow cytometry with propidium iodide and rhodamine-123 DNA-binding cationic fluorescent dyes. Fluorescence microscopy was employed to detect morphological changes in HepG2 cells following oleanolic acid treatment. The results revealed that oleanolic acid induced a dose-dependent, as well as time-dependent inhibition in the growth of HepG2 cancer cells. Following acridine orange and ethidium bromide staining, treatment with various doses (0, 5, 25 and 50 µM) of oleanolic acid induced typical morphological changes associated with apoptosis, including cell shrinkage, membrane blebbing, nuclear condensation and apoptotic body formation. Cell cycle analysis revealed that oleanolic acid induced cell cycle arrest in HepG2 cells at the sub-G1 (apoptotic) phase of the cell cycle, in a dose-dependent manner. Staining with Annexin V-fluorescein isothiocyanate and propidium iodide revealed that apoptosis occurred early in these cells. Oleanolic acid treatment also resulted in fragmentation of nuclear DNA in a dose-dependent manner, producing the typical features of DNA laddering on an agarose gel. The results also demonstrated that oleanolic acid treatment resulted in a potent loss of mitochondrial membrane potential, which also occurred in a dose-dependent manner. Therefore, oleanolic acid may be used as a therapeutic agent in the treatment of human HCC. PMID:26151733

  17. Short hairpin RNA targeting Notch2 inhibits U87 human glioma cell proliferation by inducing cell cycle arrest and apoptosis in vitro and in vivo

    PubMed Central

    LI, XUEZHEN; HE, XIN; TIAN, WEI; WANG, JIANZHEN

    2014-01-01

    Notch signaling has been reported to be oncogenic or tumor suppressive, depending on the tissue context. To investigate the effects of Notch2 knockdown on U87 human glioma cell proliferation in vitro and in vivo, and the associated mechanisms, U87 cells were stably transfected with p green fluorescent protein (GFP)-V-RS Notch2 short hairpin (sh) RNA plasmid and pGFP-V-RS scramble-shRNA plasmid. The former was referred to as the Notch2-shRNA group and the latter as the negative-shRNA group. mRNA and protein expression, cell proliferation, cell cycle and apoptosis were measured by reverse transcription-polymerase chain reaction, western blot analysis, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide analysis and flow cytometry using propidium iodide, respectively. Tumor volume, tumor weight and cumulative survival rate were determined in a nude mouse xenograft tumor model. Notch2 mRNA and protein expression in the Notch2-shRNA group were reduced by 87.6 and 94.5% compared with the negative-shRNA group (P<0.001). Notch2 knockdown significantly inhibited U87 cell proliferation after three days of culture (P<0.05). Notch2 silencing induced cell cycle arrest at G0/G1 phase by upregulation of p21 protein expression and downregulation of mini chromosome maintenance complex 2 and cyclin-D1 protein expression. Furthermore, knockdown of Notch2 also induced U87 cell apoptosis. On day 50 after inoculation, tumor weight in the Notch2-shRNA group was significantly lower than that in the negative-shRNA group (0.55±0.10 vs. 1.23±0.52 g; P<0.01). The cumulative survival rate was significantly longer in the Notch2-shRNA group compared with the negative-shRNA group (log rank test P=0.01). In conclusion, Notch2 silencing inhibited U87 glioma cell proliferation by inducing cell cycle arrest and apoptosis in vitro and in vivo. Thus, Notch2 may be a key therapeutic target for the treatment of glioma. PMID:25323114

  18. Carbon ions of different linear energy transfer (LET) values induce apoptosis & G2 cell cycle arrest in radio-resistant melanoma cells

    PubMed Central

    Jelena, Žakula; Lela, Korićanac; Otilija, Keta; Danijela, Todorović; Cirrone, Giuseppe A.P.; Francesco, Romano; Giacomo, Cuttone; Ivan, Petrović; Aleksandra, Ristić-Fira

    2016-01-01

    Background & objectives: The main goal when treating malignancies with radiation is to deprive tumour cells of their reproductive potential. One approach is to induce tumour cell apoptosis. This study was conducted to evaluate the ability of carbon ions (12C) to induce apoptosis and cell cycle arrest in human HTB140 melanoma cells. Methods: In this in vitro study, human melanoma HTB140 cells were irradiated with the 62 MeV/n carbon (12C) ion beam, having two different linear energy transfer (LET) values: 197 and 382 keV/μm. The dose range was 2 to 16 Gy. Cell viability was estimated by the sulforhodamine B assay seven days after irradiation. The cell cycle and apoptosis were evaluated 48 h after irradiation using flow cytometry. At the same time point, protein and gene expression of apoptotic regulators were estimated using the Western blot and q-PCR methods, respectively. Results: Cell viability experiments indicated strong anti-tumour effects of 12C ions. The analysis of cell cycle showed that 12C ions blocked HTB140 cells in G2 phase and induced the dose dependent increase of apoptosis. The maximum value of 21.8 per cent was attained after irradiation with LET of 197 keV/μm at the dose level of 16 Gy. Pro-apoptotic effects of 12C ions were confirmed by changes of key apoptotic molecules: the p53, Bax, Bcl-2, poly ADP ribose polymerase (PARP) as well as nuclear factor kappa B (NFκB). At the level of protein expression, the results indicated significant increases of p53, NFκB and Bax/Bcl-2 ratio and PARP cleavage. The Bax/Bcl-2 mRNA ratio was also increased, while no change was detected in the level of NFκB mRNA. Interpretation & conclusions: The present results indicated that anti-tumour effects of 12C ions in human melanoma HTB140 cells were accomplished through induction of the mitochondrial apoptotic pathway as well as G2 arrest. PMID:27748286

  19. Effects of maple (Acer) plant part extracts on proliferation, apoptosis and cell cycle arrest of human tumorigenic and non-tumorigenic colon cells.

    PubMed

    González-Sarrías, Antonio; Li, Liya; Seeram, Navindra P

    2012-07-01

    Phenolic-enriched extracts of maple sap and syrup, obtained from the sugar and red maple species (Acer saccharum Marsh, A. rubrum L., respectively), are reported to show anticancer effects. Despite traditional medicinal uses of various other parts of these plants by Native Americans, they have not been investigated for anticancer activity. Here leaves, stems/twigs, barks and sapwoods of both maple species were evaluated for antiproliferative effects against human colon tumorigenic (HCT-116, HT-29, Caco-2) and non-tumorigenic (CCD-18Co) cells. Extracts were standardized to total phenolic and ginnalin-A (isolated in our laboratory) levels. Overall, the extracts inhibited the growth of the colon cancer more than normal cells (over two-fold), their activities increased with their ginnalin-A levels, with red > sugar maple extracts. The red maple leaf extract, which contained the highest ginnalin-A content, was the most active extract (IC₅₀  = 35 and 16 µg/mL for extract and ginnalin-A, respectively). The extracts were not cytotoxic nor did they induce apoptosis of the colon cancer cells. However, cell cycle analyses revealed that the antiproliferative effects of the extracts were mediated through cell cycle arrest in the S-phase. The results from the current study suggest that these maple plant part extracts may have potential anticolon cancer effects.

  20. The Ethanolic Extract of Taiwanofungus camphoratus (Antrodia camphorata) Induces Cell Cycle Arrest and Enhances Cytotoxicity of Cisplatin and Doxorubicin on Human Hepatocellular Carcinoma Cells.

    PubMed

    Lin, Liang-Tzung; Tai, Chen-Jei; Su, Ching-Hua; Chang, Fang-Mo; Choong, Chen-Yen; Wang, Chien-Kai; Tai, Cheng-Jeng

    2015-01-01

    Taiwanofungus camphoratus (synonym Antrodia camphorata) is a widely used medicinal fungus in the folk medicine of Taiwan wit