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Sample records for lines cell cycle

  1. Change of cell cycle arrest of tumor cell lines after 60Co γ-irradiation

    International Nuclear Information System (INIS)

    Tang Yi; Liu Wenli; Zhou Jianfeng; Gao Qinglei; Wu Jianhong

    2003-01-01

    Objective: To observe the cell cycle arrest changes in peripheral blood mononuclear cells (PBMNCs) of normal persons and several kinds of tumor cell lines after 60 Co γ-irradiation. Methods: PBMNCs of normal persons, HL-60, K562, SiHA and 113 tumor cell lines were irradiated with 60 Co γ-rays at the absorbed doses of 6, 10,15 Gy. Cell cycles changes were checked 6, 12, 24, 48 and 60 h after the irradiation. Results: A stasis state was observed in normal person PBMNCs, 95 percents of which were in G 1 phase, and they still remained stasis after the irradiation. Except the 113 cell line manifesting G 1 phase arrest, all other tumor cell lines showed G 2 /M phase arrest after irradiation. The radiation sensitivity of HL-60 was higher than that of SiHA cell line. Conclusion: Different cell lines have different cell cycle arrest reaction to radiation and their radiation sensitivity are also different

  2. Radiation-induced apoptosis and cell cycle checkpoints in human colorectal tumour cell lines

    International Nuclear Information System (INIS)

    Playle, L.C.

    2001-03-01

    The p53 tumour suppressor gene is mutated in 75% of colorectal carcinomas and is critical for DNA damage-induced G1 cell cycle arrest. Data presented in this thesis demonstrate that after treatment with Ionizing Radiation (IR), colorectal tumour cell lines with mutant p53 are unable to arrest at G1 and undergo cell cycle arrest at G2. The staurosporine derivative, UCN-01, was shown to abrogate the IR-induced G2 checkpoint in colorectal tumour cell lines. Furthermore, in some cell lines, abrogation of the G2 checkpoint was associated with radiosensitisation. Data presented in this study demonstrate that 2 out of 5 cell lines with mutant p53 were sensitised to IR by UCN-01. In order to determine whether radiosensitisation correlated with lack of functional p53, transfected derivatives of an adenoma-derived cell line were studied, in which endogenous wild type p53 was disrupted by expression of a dominant negative p53 mutant protein (and with a vector control). In both these cell lines UCN-01 abrogated the G2 arrest however this was not associated with radiosensitisation, indicating that radiosensitisation is a cell type-specific phenomenon. Although 2 colorectal carcinoma cell lines, with mutant p53, were sensitised to IR by UCN-01, the mechanisms of p53-independent IR-induced apoptosis in the colon are essentially unknown. The mitogen-activated protein kinase (MAPK) pathways (that is the JNK, p38 and ERK pathways) have been implicated in apoptosis in a range of cell systems and in IR-induced apoptosis in some cell types. Data presented in this study show that, although the MAPKs can be activated by the known activator anisomycin, there is no evidence of a role for MAPKs in IR-induced apoptosis in colorectal tumour cell lines, regardless of p53 status. In summary, some colorectal tumour cell lines with mutant p53 can be sensitised to IR-induced cell death by G2 checkpoint abrogation and this may be an important treatment strategy, however mechanisms of IR-induced p53

  3. Study of the cell cycle control for human malignant mesothelioma lines. Interferon and radiations effect

    International Nuclear Information System (INIS)

    Vivo, C.

    1999-01-01

    In order to better understand the inhibition mechanisms of the IFN-R-HU on tumoral development, the IFN-R-U effect on MM lines has been studied. Three groups of lines has been distinguished: eight sensitive lines, two intermediate and three resistant. The sensitive lines showed a triple locking of the cell cycle: in phases S, G1 and G2. The study of the cell cycle control points function, realized by the MM lines radiation exposure showed the points function on G1/S and-or on G2/M and the dependence or non dependence of the cycle stop of the protein P53 and P21 W at F1/CIP1. (A.L.B.)

  4. Effects of arsenite on cell cycle progression in a human bladder cancer cell line

    International Nuclear Information System (INIS)

    Hernandez-Zavala, A.; Cordova, E.; Razo, L.M. del; Cebrian, M.E.; Garrido, E.

    2005-01-01

    Bladder cancer is one of the most important diseases associated with arsenic (As) exposure in view of its high prevalence and mortality rate. Experimental studies have shown that As exposure induces cell proliferation in the bladder of sodium arsenite (iAsIII) subchronically treated mice. However, there is little available information on its effects on the cell cycle of bladder cells. Thus, our purpose was to evaluate the effects of iAsIII on cell cycle progression and the response of p53 and p21 on the human-derived epithelial bladder cell line HT1197. iAsIII treatment (1-10 μM) for 24 h induced a dose-dependent increase in the proportion of cells in S-phase, which reached 65% at the highest dose. A progressive reduction in cell proliferation was also observed. BrdU was incorporated to cellular DNA in an interrupted form, suggesting an incomplete DNA synthesis. The time-course of iAsIII effects (10 μM) showed an increase in p53 protein content and a transient increase in p21 protein levels accompanying the changes in S-phase. These effects were correlated with iAs concentrations inside the cells, which were not able to metabolize inorganic arsenic. Our findings suggest that p21 was not able to block CDK2-cyclin E complex activity and was therefore unable to arrest cells in G1 allowing their progression into the S-phase. Further studies are needed to ascertain the mechanisms underlying the effects of iAsIII on the G1 to S phase transition in bladder cells

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

    Science.gov (United States)

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

    2016-10-18

    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 AND 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.

  6. Effects of γ-radiation on cell growth, cell cycle and promoter methylation of 22 cell cycle genes in the 1321NI astrocytoma cell line.

    Science.gov (United States)

    Alghamian, Yaman; Abou Alchamat, Ghalia; Murad, Hossam; Madania, Ammar

    2017-09-01

    DNA damage caused by radiation initiates biological responses affecting cell fate. DNA methylation regulates gene expression and modulates DNA damage pathways. Alterations in the methylation profiles of cell cycle regulating genes may control cell response to radiation. In this study we investigated the effect of ionizing radiation on the methylation levels of 22 cell cycle regulating genes in correlation with gene expression in 1321NI astrocytoma cell line. 1321NI cells were irradiated with 2, 5 or 10Gy doses then analyzed after 24, 48 and 72h for cell viability using MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliu bromide) assay. Flow cytometry were used to study the effect of 10Gy irradiation on cell cycle. EpiTect Methyl II PCR Array was used to identify differentially methylated genes in irradiated cells. Changes in gene expression was determined by qPCR. Azacytidine treatment was used to determine whether DNA methylation affectes gene expression. Our results showed that irradiation decreased cell viability and caused cell cycle arrest at G2/M. Out of 22 genes tested, only CCNF and RAD9A showed some increase in DNA methylation (3.59% and 3.62%, respectively) after 10Gy irradiation, and this increase coincided with downregulation of both genes (by 4 and 2 fold, respectively). with azacytidine confirmed that expression of CCNF and RAD9A genes was regulated by methylation. 1321NI cell line is highly radioresistant and that irradiation of these cells with a 10Gy dose increases DNA methylation of CCNF and RAD9A genes. This dose down-regulates these genes, favoring G2/M arrest. Copyright © 2017 Medical University of Bialystok. Published by Elsevier B.V. All rights reserved.

  7. Redistribution of cell cycle by arsenic trioxide is associated with demethylation and expression changes of cell cycle related genes in acute promyelocytic leukemia cell line (NB4).

    Science.gov (United States)

    Hassani, Saeed; Khaleghian, Ali; Ahmadian, Shahin; Alizadeh, Shaban; Alimoghaddam, Kamran; Ghavamzadeh, Ardeshir; Ghaffari, Seyed H

    2018-01-01

    PML-RARα perturbs the normal epigenetic setting, which is essential to oncogenic transformation in acute promyelocytic leukemia (APL). Transcription induction and recruitment of DNA methyltransferases (DNMTs) by PML-RARα and subsequent hypermethylation are components of this perturbation. Arsenic trioxide (ATO), an important drug in APL therapy, concurrent with degradation of PML-RARα induces cell cycle change and apoptosis. How ATO causes cell cycle alteration has remained largely unexplained. Here, we investigated DNA methylation patterns of cell cycle regulatory genes promoters, the effects of ATO on the methylated genes and cell cycle distribution in an APL cell line, NB4. Analysis of promoter methylation status of 22 cell cycle related genes in NB4 revealed that CCND1, CCNE1, CCNF, CDKN1A, GADD45α, and RBL1 genes were methylated 60.7, 84.6, 58.6, 8.7, 33.4, and 73.7%, respectively, that after treatment with 2 μM ATO for 48 h, turn into 0.6, 13.8, 0.1, 6.6, 10.7, and 54.5% methylated. ATO significantly reduced the expression of DNMT1, 3A, and 3B. ATO induced the expression of CCND1, CCNE1, and GADD45α genes, suppressed the expression of CCNF and CDKN1A genes, which were consistent with decreased number of cells in G1 and S phases and increased number of cells in G2/M phase. In conclusion, demethylation and alteration in the expression level of the cell cycle related genes may be possible mechanisms in ATO-induced cell cycle arrest in APL cells. It may suggest that ATO by demethylation of CCND1 and CCNE1 and their transcriptional activation accelerates G1 and S transition into the G2/M cell cycle arrest.

  8. Achillea millefolium L. hydroethanolic extract inhibits growth of human tumor cell lines by interfering with cell cycle and inducing apoptosis.

    Science.gov (United States)

    Pereira, Joana M; Peixoto, Vanessa; Teixeira, Alexandra; Sousa, Diana; Barros, Lillian; Ferreira, Isabel C F R; Vasconcelos, M Helena

    2018-06-05

    The cell growth inhibitory activity of the hydroethanolic extract of Achillea millefolium was studied in human tumor cell lines (NCI-H460 and HCT-15) and its mechanism of action was investigated. The GI 50 concentration was determined with the sulforhodamine B assay and cell cycle and apoptosis were analyzed by flow cytometry following incubation with PI or Annexin V FITC/PI, respectively. The expression levels of proteins involved in cell cycle and apoptosis were analyzed by Western blot. The extracts were characterized regarding their phenolic composition by LC-DAD-ESI/MS. 3,5-O-Dicaffeoylquinic acid, followed by 5-O-caffeoylquinic acid, were the main phenolic acids, while, luteolin-O-acetylhexoside and apigenin-O-acetylhexoside were the main flavonoids. This extract decreased the growth of the tested cell lines, being more potent in HCT-15 and then in NCI-H460 cells. Two different concentrations of the extract (75 and 100 μg/mL) caused alterations in cell cycle profile and increased apoptosis levels in HCT-15 and NCI-H460 cells. Moreover, the extract caused an increase in p53 and p21 expression in NCI-H460 cells (which have wt p53), and reduced XIAP levels in HCT-15 cells (with mutant p53). This work enhances the importance of A. millefolium as source of bioactive phenolic compounds, particularly of XIAP inhibitors. Copyright © 2018 Elsevier Ltd. All rights reserved.

  9. Polyamine metabolism during the cell cycle of synchronized tobacco BY-2 cell line

    Czech Academy of Sciences Publication Activity Database

    Gemperlová, Lenka; Cvikrová, Milena; Fischerová, Lucie; Binarová, Pavla; Fischer, L.; Eder, Josef

    2009-01-01

    Roč. 47, č. 7 (2009), s. 584-591 ISSN 0981-9428 R&D Projects: GA AV ČR IAA500200719 Institutional research plan: CEZ:AV0Z50380511; CEZ:AV0Z50200510 Keywords : ADC * Cell cycle * DAO Subject RIV: EF - Botanics Impact factor: 2.485, year: 2009

  10. Establishment and cell cycle distribution pattern of a radioresistant subline from human lung cancer D6 cell line

    International Nuclear Information System (INIS)

    Wei Qichun; Zheng Shu

    2003-01-01

    Objective: To establish a radioresistant cell subline from a human D6 lung cancer cell line and investigate the mechanism of radioresistance. Methods: D6 human NSCLC cells were exposed to X-rays generated by a linear accelerator(650 cGy per fraction). After a total exposure dose of 5200 cGy, a monoclone was obtained. The radiosensitivity and cell cycle distribution of this clone, together with its parent D6 cells, were measured by clonogenic assay and flow cytometry. Results: The new clone, namely D 6 -R subline, had a higher D 0 (D 0 =2.08 Gy) and a broader initial shoulder(Dq=1.64 Gy, N=2.20) than those of the parent D6 cell line (D 0 =1.84 Gy, Dq=0.34 Gy, N=1.20), being 1.65-fold increase in radioresistance as regards to the SF 2 . The D6-R subline also showed higher percentage of cells in S phase(53.4% vs 37.8%), but lower percentages in G 1 (44.1% vs 57.2%) and G 2 /M(2.5% vs 5%) phases. Conclusion: The new subline D6-R is more radioresistant as compare to its parent D6 cell line, and has a different cell cycle distribution

  11. Characterization of a mutant rat kangaroo cell line with alterations in the cell cycle and DNA repair

    Directory of Open Access Journals (Sweden)

    Miyaji E.N.

    2000-01-01

    Full Text Available Using a positive selection system for isolating DNA replication and repair related mutants, we isolated a clone from a rat kangaroo cell line (PtK2 that has increased sensitivity to UV light. Characterization of this clone indicated normal post-replication repair after UV irradiation, and normal removal rates of cyclobutane pyrimidine dimers and pyrimidine(6-4pyrimidone photoproducts by excision repair. However, this cell line has decreased ability to make early incisions on damaged DNA, possibly indicating a defect in preferential repair of actively transcribed genes, and a slower cell proliferation rate, including a longer S-phase. This phenotype reinforces the present notion that control of key mechanisms in cell metabolism, such as cell cycle control, repair, transcription and cell death, can be linked.

  12. Cryptotanshinone has diverse effects on cell cycle events in melanoma cell lines with different metastatic capacity

    OpenAIRE

    Punchard, Neville

    2011-01-01

    Background and Purpose: Cryptotanshinone (CTs) is a major active component of Salvia miltiorrhiza, which is often used as Chinese herbal medicine in cancer therapy. Here, we systematically assessed the anti-tumor effect of CTs on two melanoma cell lines with low/high metastatic capacity (B16/B16BL6). Experimental Approach: MTT and LDH assays were used to evaluate cell growth and cytotoxicity. We assessed the effect of CTs on cell apoptosis or proliferation by Annexin V, TUNEL or BrdU assay. C...

  13. Evolution of cell resistance, threshold voltage and crystallization temperature during cycling of line-cell phase-change random access memory

    NARCIS (Netherlands)

    Oosthoek, J. L. M.; Attenborough, K.; Hurkx, G. A. M.; Jedema, F. J.; Gravesteijn, D. J.; Kooi, B. J.

    2011-01-01

    Doped SbTe phase change (PRAM) line cells produced by e-beam lithography were cycled 100 million times. During cell cycling the evolution of many cell properties were monitored, in particular the crystalline and amorphous resistance, amorphous resistance drift exponent, time-dependent threshold

  14. Intermittent Stem Cell Cycling Balances Self-Renewal and Senescence of the C. elegans Germ Line.

    Directory of Open Access Journals (Sweden)

    Amanda Cinquin

    2016-04-01

    Full Text Available Self-renewing organs often experience a decline in function in the course of aging. It is unclear whether chronological age or external factors control this decline, or whether it is driven by stem cell self-renewal-for example, because cycling cells exhaust their replicative capacity and become senescent. Here we assay the relationship between stem cell cycling and senescence in the Caenorhabditis elegans reproductive system, defining this senescence as the progressive decline in "reproductive capacity," i.e. in the number of progeny that can be produced until cessation of reproduction. We show that stem cell cycling diminishes remaining reproductive capacity, at least in part through the DNA damage response. Paradoxically, gonads kept under conditions that preclude reproduction keep cycling and producing cells that undergo apoptosis or are laid as unfertilized gametes, thus squandering reproductive capacity. We show that continued activity is in fact beneficial inasmuch as gonads that are active when reproduction is initiated have more sustained early progeny production. Intriguingly, continued cycling is intermittent-gonads switch between active and dormant states-and in all likelihood stochastic. Other organs face tradeoffs whereby stem cell cycling has the beneficial effect of providing freshly-differentiated cells and the detrimental effect of increasing the likelihood of cancer or senescence; stochastic stem cell cycling may allow for a subset of cells to preserve proliferative potential in old age, which may implement a strategy to deal with uncertainty as to the total amount of proliferation to be undergone over an organism's lifespan.

  15. Phytol isolated from watermelon (Citrullus lanatus) sprouts induces cell death in human T-lymphoid cell line Jurkat cells via S-phase cell cycle arrest.

    Science.gov (United States)

    Itoh, Tomohiro; Ono, Akito; Kawaguchi, Kaori; Teraoka, Sayaka; Harada, Mayo; Sumi, Keitaro; Ando, Masashi; Tsukamasa, Yasuyuki; Ninomiya, Masayuki; Koketsu, Mamoru; Hashizume, Toshiharu

    2018-05-01

    The phytol isolated from watermelon (Citrullus lanatus) sprouts inhibited the growth of a human T-cell leukemia line Jurkat cell and suppressed tumor progression in a xenograft model of human lung adenocarcinoma epithelial cell line A549 in nude mice. To elucidate the mechanisms underlying the phytol-induced cell death in the present study, we examined the changes in cell morphology, DNA fragmentation, and intracellular reactive oxygen species (ROS) levels and performed flow cytometric analysis to evaluate cell cycle stage. There were no significant changes in apoptosis, autophagy, and necrosis marker in cells treated with the phytol. But, we found, for the first time, that phytol remarkably induced S-phase cell cycle arrest accompanied with intracellular ROS production. Western blot analyses showed that phytolinduced S-phase cell cycle arrest was mediated through the decreased expression of cyclins A and D and the downregulations of MAPK and PI3K/Akt. The tumor volume levels in mice treated with phytol were lower than those of non-treatment groups, and it showed very similar suppression compared with those of mice treated with cyclophosphamide. Based on the data of in vitro and in vivo studies and previous studies, we suggest phytol as a potential therapeutic compound for cancer. Copyright © 2018 Elsevier Ltd. All rights reserved.

  16. Effect of ionizing radiation in combination with 5-flurouracil on cell cycle uncoupling of EL-4 cell line

    International Nuclear Information System (INIS)

    Liu Yang; Sun Yanhong; Zhang Xuan; Gong Shouliang; Zhang Wei; Li Song

    2009-01-01

    Objective: To observe the dose-and time-effect of ionizing radiation in combination with 5-flurouracil(5-FU) on the cell cycle uncoupling of EL-4 cell line. Methods: EL-4 cells were collected after irradiation with 0,1.0,2.0 and 4.0 Gy X-irradiation and treatment with 5-FU(0.001,0.010,0.100 and 1.000 mg·L -1 ) for 0,4,8,16,24 and 48 h.The regularity in the polyloid cells was analyzed by flow cytometry(FCM) following staining cells with propidium iodide(PI). Results: As compared with sham-irradiation group,the percentage of diploid EL-4 cells increased significantly at 8-24 h and returned to normal level at 48 h after irradiation with 2.0 Gy X-rays(P -1 group, the percentage of diploid cells decreased obviously at 16-48 h after treatment with 0.100 mg·L -1 5-FU(P -1 group, the percentage of diploid cells decreased significantly 16 h after treatment with different doses 5-FU(P -1 ; the percentage of octoploid cells increased significantly after treatment with 0.010 and 0.100 mg·L -1 5-Fu(P -1 5-FU. (authors)

  17. Six versus fewer planned cycles of first-line platinum-based chemotherapy for non-small-cell lung cancer

    DEFF Research Database (Denmark)

    Rossi, Antonio; Chiodini, Paolo; Sun, Jong-Mu

    2014-01-01

    BACKGROUND: Platinum-based chemotherapy is the standard first-line treatment for patients with advanced non-small-cell lung cancer. However, the optimum number of treatment cycles remains controversial. Therefore, we did a systematic review and meta-analysis of individual patient data to compare ...

  18. Solutions for the Cell Cycle in Cell Lines Derived from Human Tumors

    Directory of Open Access Journals (Sweden)

    B. Zubik-Kowal

    2006-01-01

    Full Text Available The goal of the paper is to compute efficiently solutions for model equations that have the potential to describe the growth of human tumor cells and their responses to radiotherapy or chemotherapy. The mathematical model involves four unknown functions of two independent variables: the time variable t and dimensionless relative DNA content x. The unknown functions can be thought of as the number density of cells and are solutions of a system of four partial differential equations. We construct solutions of the system, which allow us to observe the number density of cells for different t and x values. We present results of our experiments which simulate population kinetics of human cancer cells in vitro. Our results show a correspondence between predicted and experimental data.

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

    Directory of Open Access Journals (Sweden)

    Yukari Takahashi

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

  20. Effects of ultraviolet irradiation on the cell cycle in normal and UV-sensitive cell lines with reference to the nature of the defect in xeroderma pigmentosum variant

    International Nuclear Information System (INIS)

    Imray, P.; Mangan, T.; Saul, A.; Kidson, C.

    1983-01-01

    Analysis of the distribution of cells through the phases of the cell cycle by DNA flow cytofluorimetry has been utilized to investigate the effects of ultraviolet (UV) irradiation on cell-cycle progression in normal and UV-sensitive lymphoblastoid cell lines. In time-course studies only slight perturbation of DNA distribution was seen in normal cells, or UV-sensitive familial melanoma (FM) lines in the 48 h following irradiation. Xeroderma pigmentosum (XPA) excision-deficient cells showed a large increase in the proportion of cells in S phase 16-40 h post-irradiation. XP variant (XPV) cells were blocked in G 1 and S phases with the complete absence of cells with G 2 DNA content 16-28 h after irradiation. By 48 h post-irradiation the DNA distribution of XPA and XPV cells had returned to that of an unirradiated control. When colcemid was added to the cultures immediately after irradiation to prevent mitotic cells dividing and re-entering the cell cycle, progression through the first cycle after irradiation was followed. UV irradiation did not affect the rate of movement of cells out of G 1 into S phase in normal, FM or XPA cells. The proportion of cells in S phase was increased in UV-irradiated cultures in these cell types and the number of cells entering the G 2 +M compartment was reduced. (orig./AJ)

  1. Effect of dihydroartemisinin on the cell cycle progress of irradiated human cervical cancer cell line and its mechanism

    International Nuclear Information System (INIS)

    Chen Xialin; Ji Rong; Cao Jianping; Zhu Wei; Fan Sanjun; Wang Jianfang; Cao Jianping

    2010-01-01

    Objective: To observe the changes of cell cycle on cancer cells after dihydroartemisinin and X-ray irradiation. Methods: Human HeLa cells of cervical cancer with p53 mutation was used and human SiHa cells of cervical cancer with wild p53 was used as control. Flow cytometry was used to detect the effect of dihydroartemisinin (20 and 100 μmol/L) and irradiation (6 Gy)on cell cycle. Western blot was used to measure the levels of cell cycle protein. Results: G 2 arrest was observed in irradiated HeLa cells, which the proportion of cells in G 2 phase was increased from 14.45% to 73.58% after 6 Gy X-ray irradiation, but it was abrogated by dihydroartemisinin from 73. 58% to 48.31% in HeLa cells, and it had no change on the SiHa cells. The elevated Wee1 protein and the lowered Cyclin B1 protein were observed with the G 2 arrest severity. The expression of radiation-induced Wee1 protein was suppressed and the Cyclin B1 protein was increased after dihydroartemisinin treatment, which was in accordance with the abrogation of radiation-induced G 2 delay. Conclusions: The main effect of irradiation on cell cycle of p53 mutated HeLa cells is G 2 arrest. Dihydroartemisinin could abrogate it, which is associated with the changes of Wee1 protein and Cyclin B1 protein. In Siha cells, the main effect of irradiation on cell cycle is G 1 arrest, and dihydroartemisinin has no effect on it. (authors)

  2. [Effects of HSP90 inhibitor 17-AAG on cell cycle and apoptosis of human gastric cancer cell lines SGC-7901].

    Science.gov (United States)

    Chen, Meini; Xu, Jinghong; Zhao, Jumei

    2013-02-01

    To study the effect of the HSP90 inhibitor, 17-allylamino-17-demethoxygeldanamycin (17-AAG), on cell proliferation and apoptosis of human cancer SGC-7901 cells and explore the mechanisms. The inhibitory effect of 17-AAG on the proliferation and morphology of SGC-7901 cells was assessed with MTT assay and DNA-PI staining, respectively. Flow cytometry was employed to analyze the changes in cell cycle and apoptosis of the cells following 17-AAG exposure. The cellular expression of Fas protein was detected by immunohistochemistry. 17-AAG significantly suppressed the proliferation of SGC-7901 cells in a time- and dose-dependent manner. After treatment with 17-AAG for 48 h, SGC-7901 cells showed cell cycle arrested at G(2)/M stage, and the cell apoptosis rate increased with the 17-AAG concentration. The expression of Fas protein in the cytoplasm of SGC-7901 cells increased gradually with the increase of 17-AAG concentration. 17-AAG can induce apoptosis, alters the cell cycle distribution and up-regulates the expression of Fas protein in SGC-7901 cells to suppress the cell proliferation.

  3. Characterization of a mutant rat kangaroo cell line with alterations in the cell cycle and DNA repair

    OpenAIRE

    Miyaji, E.N.; Johnson, R.T.; Downes, C.S.; Eveno, E.; Mezzina, M.; Sarasin, A.; Menck, C.F.M.

    2000-01-01

    Using a positive selection system for isolating DNA replication and repair related mutants, we isolated a clone from a rat kangaroo cell line (PtK2) that has increased sensitivity to UV light. Characterization of this clone indicated normal post-replication repair after UV irradiation, and normal removal rates of cyclobutane pyrimidine dimers and pyrimidine(6-4)pyrimidone photoproducts by excision repair. However, this cell line has decreased ability to make early incisions on damaged DNA, po...

  4. Temperature oscillations drive cycles in the activity of MMP-2,9 secreted by a human trabecular meshwork cell line.

    Science.gov (United States)

    Li, Stanley Ka-Lok; Banerjee, Juni; Jang, Christopher; Sehgal, Amita; Stone, Richard A; Civan, Mortimer M

    2015-02-05

    Aqueous humor inflow falls 50% during sleeping hours without proportional fall in IOP, partly reflecting reduced outflow facility. The mechanisms underlying outflow facility cycling are unknown. One outflow facility regulator is matrix metalloproteinase (MMP) release from trabecular meshwork (TM) cells. Because anterior segment temperature must oscillate due to core temperature cycling and eyelid closure during sleep, we tested whether physiologically relevant temperature oscillations drive cycles in the activity of secreted MMP. Temperature of transformed normal human TM cells (hTM5 line) was fixed or alternated 12 hours/12 hours between 33°C and 37°C. Activity of secreted MMP-2 and MMP-9 was measured by zymography, and gene expression by RT-PCR and quantitative PCR. Raising temperature to 37°C increased, and lowering to 33°C reduced, activity of secreted MMP. Switching between 37°C and 33°C altered MMP-9 by 40% ± 3% and MMP-2 by 22% ± 2%. Peripheral circadian clocks did not mediate temperature-driven cycling of MMP secretion because MMP-release oscillations did not persist at constant temperature after 3 to 6 days of alternating temperatures, and temperature cycles did not entrain clock-gene expression in these cells. Furthermore, inhibiting heat shock transcription factor 1, which links temperature and peripheral clock-gene oscillations, inhibited MMP-9 but not MMP-2 temperature-driven MMP cycling. Inhibition of heat-sensitive TRPV1 channels altered total MMP secretion but not temperature-induced modulations. Inhibiting cold-sensitive TRPM-8 channels had no effect. Physiologically relevant temperature oscillations drive fluctuations of secreted MMP-2 and MMP-9 activity in hTM5 cells independent of peripheral clock genes and temperature-sensitive TRP channels. Copyright 2015 The Association for Research in Vision and Ophthalmology, Inc.

  5. Increased radiosensitivity of HPV-positive head and neck cancer cell lines due to cell cycle dysregulation and induction of apoptosis

    International Nuclear Information System (INIS)

    Arenz, Andrea; Ziemann, Frank; Wittig, Andrea; Preising, Stefanie; Engenhart-Cabillic, Rita; Mayer, Christina; Wagner, Steffen; Klussmann, Jens-Peter; Wittekindt, Claus; Dreffke, Kirstin

    2014-01-01

    Human Papillomavirus (HPV)-related head and neck squamous cell carcinoma (HNSCC) respond favourably to radiotherapy as compared to HPV-unrelated HNSCC. We investigated DNA damage response in HPV-positive and HPV-negative HNSCC cell lines aiming to identify mechanisms, which illustrate reasons for the increased sensitivity of HPV-positive cancers of the oropharynx. Radiation response including clonogenic survival, apoptosis, DNA double-strand break (DSB) repair, and cell cycle redistribution in four HPV-positive (UM-SCC-47, UM-SCC-104, 93-VU-147T, UPCI:SCC152) and four HPV-negative (UD-SCC-1, UM-SCC-6, UM-SCC-11b, UT-SCC-33) cell lines was evaluated. HPV-positive cells were more radiosensitive (mean SF2: 0.198 range: 0.22-0.18) than HPV-negative cells (mean SF2: 0.34, range: 0.45-0.27; p = 0.010). Irradiated HPV-positive cell lines progressed faster through S-phase showing a more distinct accumulation in G2/M. The abnormal cell cycle checkpoint activation was accompanied by a more pronounced increase of cell death after x-irradiation and a higher number of residual and unreleased DSBs. The enhanced responsiveness of HPV-related HNSCC to radiotherapy might be caused by a higher cellular radiosensitivity due to cell cycle dysregulation and impaired DNA DSB repair. (orig.) [de

  6. Genome Wide Expression Profiling of Cancer Cell Lines Cultured in Microgravity Reveals Significant Dysregulation of Cell Cycle and MicroRNA Gene Networks.

    Directory of Open Access Journals (Sweden)

    Prasanna Vidyasekar

    Full Text Available Zero gravity causes several changes in metabolic and functional aspects of the human body and experiments in space flight have demonstrated alterations in cancer growth and progression. This study reports the genome wide expression profiling of a colorectal cancer cell line-DLD-1, and a lymphoblast leukemic cell line-MOLT-4, under simulated microgravity in an effort to understand central processes and cellular functions that are dysregulated among both cell lines. Altered cell morphology, reduced cell viability and an aberrant cell cycle profile in comparison to their static controls were observed in both cell lines under microgravity. The process of cell cycle in DLD-1 cells was markedly affected with reduced viability, reduced colony forming ability, an apoptotic population and dysregulation of cell cycle genes, oncogenes, and cancer progression and prognostic markers. DNA microarray analysis revealed 1801 (upregulated and 2542 (downregulated genes (>2 fold in DLD-1 cultures under microgravity while MOLT-4 cultures differentially expressed 349 (upregulated and 444 (downregulated genes (>2 fold under microgravity. The loss in cell proliferative capacity was corroborated with the downregulation of the cell cycle process as demonstrated by functional clustering of DNA microarray data using gene ontology terms. The genome wide expression profile also showed significant dysregulation of post transcriptional gene silencing machinery and multiple microRNA host genes that are potential tumor suppressors and proto-oncogenes including MIR22HG, MIR17HG and MIR21HG. The MIR22HG, a tumor-suppressor gene was one of the highest upregulated genes in the microarray data showing a 4.4 log fold upregulation under microgravity. Real time PCR validated the dysregulation in the host gene by demonstrating a 4.18 log fold upregulation of the miR-22 microRNA. Microarray data also showed dysregulation of direct targets of miR-22, SP1, CDK6 and CCNA2.

  7. Indole-3-carbinol induces G1 cell cycle arrest and apoptosis through aryl hydrocarbon receptor in THP-1 monocytic cell line.

    Science.gov (United States)

    Mohammadi, Saeed; Seyedhosseini, Fakhri Sadat; Behnampour, Nasser; Yazdani, Yaghoub

    2017-10-01

    The role of aryl hydrocarbon receptor (AhR) in carcinogenesis has been studied recently. Indole-3-carbinol (I3C) is an AhR agonist and a potential anticancer agent. Here, we investigated the effects of I3C on cell cycle progression and apoptosis through activation of AhR on THP-1 acute myeloid leukemia (AML) cell line. MTT viability assay was used to measure the cytotoxic effects of I3C on THP-1 cells. Apoptosis and cell cycle assays were investigated using flow cytometry. Real time RT-PCR was conducted to measure the alterations in the expression of AhR gene, key genes associated with AhR activation (IL1β and CYP1A1) and major genes involved in cell cycle regulation and apoptosis including P27, P21, CDK2, P53, BCL2 and FasR. Our findings revealed that I3C inhibits the proliferation of THP-1 cells in a dose- and time-dependent manner with minimal toxicity over normal monocytes. The AhR target genes (CYP1A1, IL1β) were overexpressed upon I3C treatment (p cycle arrest was also observed using flow cytometry. G1-acting cell cycle genes (P21, P27 and P53) were overexpressed (p cycle arrest in a dose- and time-dependent manner. Therefore, AhR could be targeted as a novel treatment possibility in AML.

  8. DNA Amplification by Breakage/Fusion/Bridge Cycles Initiated by Spontaneous Telomere Loss in a Human Cancer Cell Line

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    Anthony W.l. Lo

    2002-01-01

    Full Text Available The development of genomic instability is an important step in generatingthe multiple genetic changes required for cancer. One consequence of genomic instability is the overexpression of oncogenes due to gene amplification. One mechanism for gene amplification is the breakagelfusionlbridge (B/F/Bcyclethatinvolvesthe repeated fusion and breakage of chromosomes following the loss of a telomere. B/F/B cycles have been associated with low-copy gene amplification in human cancer cells, and have been proposed to be an initiating event in high-copy gene amplification. We have found that spontaneous telomere loss on a marker chromosome 16 in a human tumor cell line results in sister chromatid fusion and prolonged periods of chromosome instability. The high rate of anaphase bridges involving chromosome 16 demonstrates that this instability results from B/F/B cycles. The amplification of subtelomeric DNA on the marker chromosome provides conclusive evidence that B/F/B cycles initiated by spontaneous telomere loss are a mechanism for gene amplification in human cancer cells.

  9. Glucocorticoid effect on melphalan cytotoxicity, cell-cycle position, cell size, and [3H]uridine incorporation in one of three human melanoma cell lines

    International Nuclear Information System (INIS)

    Benckhuijsen, C.; Osman, A.M.; Hillebrand, M.J.; Smets, L.A.

    1987-01-01

    Three human melanoma cell lines of known content of specific glucocorticoid-binding sites were studied for colony formation after a microM dose of glucocorticoid combined with melphalan. In one of the three cell lines, M-5A, subcloned from M-5 (formerly designated RPMI 8322), the effect of combined treatment was markedly increased compared to that of melphalan even if the glucocorticoid was applied for 1 h only, 10 h before the melphalan. Semilogarithmic dose-effect plots for a reduction of final plating efficiency by glucocorticoid were curvilinear, according to a receptor-mediated process. The effects of glucocorticoid, melphalan, and their combination were linearized by bilogarithmic median-effect plotting which allowed the quantitation of a synergism which was more marked in case of glucocorticoid pretreatment, for 1 or 24 h, than on simultaneous exposure. According to sequential DNA per cell cytophotometry, melphalan abolished in M-5A a glucocorticoid-induced arrest in the G1 phase of the cell cycle. The cytotoxic synergism correlated with an apparent stimulation by glucocorticoid of the rate of acid-insoluble incorporation of [ 3 H]uridine and [ 14 C]leucine and an increase in cell size and protein content in M-5A cells but not in the other two cell lines. The way in which glucocorticoids induce an enhanced susceptibility to melphalan is not clear. Our results appear compatible with a hypothesis that chromatin in a transcriptionally activated state is more vulnerable to cytotoxic attack by an alkylating agent than under average conditions

  10. Platinum(IV) complex LA-12 induces cell cycle phase specific apoptosis in colon carcinoma cell line HCT-116

    Czech Academy of Sciences Publication Activity Database

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

    2009-01-01

    Roč. 276, č. 1 (2009), s. 256-257 ISSN 1742-464X. [34th FEBS Congress. 04.07.2009-09.07.2009, Prague] R&D Projects: GA AV ČR(CZ) 1QS500040507; GA ČR(CZ) GA301/07/1557 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : platinum drugs * cell cycle apoptosis Subject RIV: BO - Biophysics

  11. DNA fragmentation and cell cycle arrest: a hallmark of apoptosis induced by crocin from kashmiri saffron in a human pancreatic cancer cell line.

    Science.gov (United States)

    Bakshi, Hamid; Sam, Smitha; Rozati, Roya; Sultan, Phalisteen; Islam, Tajamul; Rathore, Babita; Lone, Zahoor; Sharma, Manik; Triphati, Jagrati; Saxena, Ramesh Chand

    2010-01-01

    Apoptosis, a widely important mechanism that contributes to cell growth reduction, is reported to be induced by Crocus sativus in different cancer types. The present study was designed to elucidate apoptosis induction by crocin, a main component of Crocus sativus in a human pancreatic cancer cell line (BxPC-3). Cell viability was measured by MTT assay, Hoechest33258 staining was used to detect the chromatin condensation characteristic of apoptosis, and DNA fragmentation was assessed by gel electrophoresis and cell cycle analysis by flow cytometry. Crocin induced apoptosis and G1-phase cell cycle arrest of BxPC-3 cells, while decreasing cell viability in a dose dependent and time dependent manner. Cells treated with 10μg/L crocin exhibited apoptotic morphology (brightly blue-fluorescent condensed nuclei on Hoechst 33258 staining) and reduction of volume. DNA analysis revealed typical ladders as early as 12 hours after treatment indicative of apoptosis. Our preclinical study demonstrated a pancreatic cancer cell line to be highly sensitive to crocin-mediated growth inhibition and apoptotic cell death. Although the molecular mechanisms of crocin action are not yet clearly understood, it appears to have potential as a therapeutic agent.

  12. P276-00, a cyclin-dependent kinase inhibitor, modulates cell cycle and induces apoptosis in vitro and in vivo in mantle cell lymphoma cell lines

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    Shirsath Nitesh P

    2012-10-01

    Full Text Available Abstract Background Mantle cell lymphoma (MCL is a well-defined aggressive lymphoid neoplasm characterized by proliferation of mature B-lymphocytes that have a remarkable tendency to disseminate. This tumor is considered as one of the most aggressive lymphoid neoplasms with poor responses to conventional chemotherapy and relatively short survival. Since cyclin D1 and cell cycle control appears as a natural target, small-molecule inhibitors of cyclin-dependent kinases (Cdks and cyclins may play important role in the therapy of this disorder. We explored P276-00, a novel selective potent Cdk4-D1, Cdk1-B and Cdk9-T1 inhibitor discovered by us against MCL and elucidated its potential mechanism of action. Methods The cytotoxic effect of P276-00 in three human MCL cell lines was evaluated in vitro. The effect of P276-00 on the regulation of cell cycle, apoptosis and transcription was assessed, which are implied in the pathogenesis of MCL. Flow cytometry, western blot, immunoflourescence and siRNA studies were performed. The in vivo efficacy and effect on survival of P276-00 was evaluated in a Jeko-1 xenograft model developed in SCID mice. PK/PD analysis of tumors were performed using LC-MS and western blot analysis. Results P276-00 showed a potent cytotoxic effect against MCL cell lines. Mechanistic studies confirmed down regulation of cell cycle regulatory proteins with apoptosis. P276-00 causes time and dose dependent increase in the sub G1 population as early as from 24 h. Reverse transcription PCR studies provide evidence that P276-00 treatment down regulated transcription of antiapoptotic protein Mcl-1 which is a potential pathogenic protein for MCL. Most importantly, in vivo studies have revealed significant efficacy as a single agent with increased survival period compared to vehicle treated. Further, preliminary combination studies of P276-00 with doxorubicin and bortezomib showed in vitro synergism. Conclusion Our studies thus provide

  13. Investigation of the Effects of Perfluorooctanoic Acid (PFOA and Perfluorooctane Sulfonate (PFOS on Apoptosis and Cell Cycle in a Zebrafish (Danio rerio Liver Cell Line

    Directory of Open Access Journals (Sweden)

    Yuan Cui

    2015-12-01

    Full Text Available This study aimed to explore the effects of perfluorooctanoic acid (PFOA and perfluorooctane sulfonate (PFOS on apoptosis and cell cycle in a zebrafish (Danio rerio liver cell line (ZFL. Treatment groups included a control group, PFOA-IC50, PFOA-IC80, PFOS-IC50 and PFOS-IC80 groups. IC50 and IC80 concentrations were identified by cellular modeling and MTT assays. mRNA levels of p53, Bcl-2, Bax, Caspase-3 and NF-κB p65 were detected by qPCR. Cell apoptosis and cell cycle were detected by flow cytometry and the protein levels of p53, Bcl-2, Bax, Caspase-3 and NF-κB p65 were determined by western blotting. Both PFOA and PFOS inhibited the growth of zebrafish liver cells, and the inhibition rate of PFOS was higher than that of PFOA. Bcl-2 expression levels in the four groups were significantly higher than the control group and Bcl-2 increased significantly in the PFOA-IC80 group. However, the expression levels of Bax in the four treatment groups were higher than the control group. The percentage of cell apoptosis increased significantly with the treatment of PFOA and PFOS (p < 0.05. Cell cycle and cell proliferation were blocked in both the PFOA-IC80 and PFOS-IC80 groups, indicating that PFOA-IC80 and PFOS-IC50 enhanced apoptosis in ZFL cells.

  14. Inhibitory effect of turmeric curcuminoids on FLT3 expression and cell cycle arrest in the FLT3-overexpressing EoL-1 leukemic cell line.

    Science.gov (United States)

    Tima, Singkome; Ichikawa, Hideki; Ampasavate, Chadarat; Okonogi, Siriporn; Anuchapreeda, Songyot

    2014-04-25

    Leukemia is a hematologic malignancy with a frequent incidence and high mortality rate. Previous studies have shown that the FLT3 gene is overexpressed in leukemic blast cells, especially in acute myeloid leukemia. In this study, a commercially available curcuminoid mixture (1), pure curcumin (2), pure demethoxycurcumin (3), and pure bisdemethoxycurcumin (4) were investigated for their inhibitory effects on cell growth, FLT3 expression, and cell cycle progression in an FLT3-overexpressing EoL-1 leukemic cell line using an MTT assay, Western blotting, and flow cytometry, respectively. The mixture (1) and compounds 2-4 demonstrated cytotoxic effects with IC50 values ranging from 6.5 to 22.5 μM. A significant decrease in FLT3 protein levels was found after curcuminoid treatment with IC20 doses, especially with mixture 1 and compound 2. In addition, mixture 1 and curcumin (2) showed activity on cell cycle arrest at the G0/G1 phase and decreased the FLT3 and STAT5A protein levels in a dose-dependent manner. Compound 2 demonstrated the greatest potential for inhibiting cell growth, cell cycle progression, and FLT3 expression in EoL-1 cells. This investigation has provided new findings regarding the effect of turmeric curcuminoids on FLT3 expression in leukemic cells.

  15. Citric acid induces cell-cycle arrest and apoptosis of human immortalized keratinocyte cell line (HaCaT) via caspase- and mitochondrial-dependent signaling pathways.

    Science.gov (United States)

    Ying, Tsung-Ho; Chen, Chia-Wei; Hsiao, Yu-Ping; Hung, Sung-Jen; Chung, Jing-Gung; Yang, Jen-Hung

    2013-10-01

    Citric acid is an alpha-hydroxyacid (AHA) widely used in cosmetic dermatology and skincare products. However, there is concern regarding its safety for the skin. In this study, we investigated the cytotoxic effects of citric acid on the human keratinocyte cell line HaCaT. HaCaT cells were treated with citric acid at 2.5-12.5 mM for different time periods. Cell-cycle arrest and apoptosis were investigated by 4,6-diamidino-2-phenylindole dihydrochloride (DAPI) staining, flow cytometry, western blot and confocal microscopy. Citric acid not only inhibited proliferation of HaCaT cells in a dose-dependent manner, but also induced apoptosis and cell cycle-arrest at the G2/M phase (before 24 h) and S phase (after 24 h). Citric acid increased the level of Bcl-2-associated X protein (BAX) and reduced the levels of B-cell lymphoma-2 (BCL-2), B-cell lymphoma-extra large (BCL-XL) and activated caspase-9 and caspase-3, which subsequently induced apoptosis via caspase-dependent and caspase-independent pathways. Citric acid also activated death receptors and increased the levels of caspase-8, activated BH3 interacting-domain death agonist (BID) protein, Apoptosis-inducing factor (AIF), and Endonuclease G (EndoG). Therefore, citric acid induces apoptosis through the mitochondrial pathway in the human keratinocyte cell line HaCaT. The study results suggest that citric acid is cytotoxic to HaCaT cells via induction of apoptosis and cell-cycle arrest in vitro.

  16. The immunomodulator PSK induces in vitro cytotoxic activity in tumour cell lines via arrest of cell cycle and induction of apoptosis

    International Nuclear Information System (INIS)

    Jiménez-Medina, Eva; Berruguilla, Enrique; Romero, Irene; Algarra, Ignacio; Collado, Antonia; Garrido, Federico; Garcia-Lora, Angel

    2008-01-01

    Protein-bound polysaccharide (PSK) is derived from the CM-101 strain of the fungus Coriolus versicolor and has shown anticancer activity in vitro and in in vivo experimental models and human cancers. Several randomized clinical trials have demonstrated that PSK has great potential in adjuvant cancer therapy, with positive results in the adjuvant treatment of gastric, esophageal, colorectal, breast and lung cancers. These studies have suggested the efficacy of PSK as an immunomodulator of biological responses. The precise molecular mechanisms responsible for its biological activity have yet to be fully elucidated. The in vitro cytotoxic anti-tumour activity of PSK has been evaluated in various tumour cell lines derived from leukaemias, melanomas, fibrosarcomas and cervix, lung, pancreas and gastric cancers. Tumour cell proliferation in vitro was measured by BrdU incorporation and viable cell count. Effect of PSK on human peripheral blood lymphocyte (PBL) proliferation in vitro was also analyzed. Studies of cell cycle and apoptosis were performed in PSK-treated cells. PSK showed in vitro inhibition of tumour cell proliferation as measured by BrdU incorporation and viable cell count. The inhibition ranged from 22 to 84%. Inhibition mechanisms were identified as cell cycle arrest, with cell accumulation in G 0 /G 1 phase and increase in apoptosis and caspase-3 expression. These results indicate that PSK has a direct cytotoxic activity in vitro, inhibiting tumour cell proliferation. In contrast, PSK shows a synergistic effect with IL-2 that increases PBL proliferation. These results indicate that PSK has cytotoxic activity in vitro on tumour cell lines. This new cytotoxic activity of PSK on tumour cells is independent of its previously described immunomodulatory activity on NK cells

  17. The immunomodulator PSK induces in vitro cytotoxic activity in tumour cell lines via arrest of cell cycle and induction of apoptosis

    Directory of Open Access Journals (Sweden)

    Garrido Federico

    2008-03-01

    Full Text Available Abstract Background Protein-bound polysaccharide (PSK is derived from the CM-101 strain of the fungus Coriolus versicolor and has shown anticancer activity in vitro and in in vivo experimental models and human cancers. Several randomized clinical trials have demonstrated that PSK has great potential in adjuvant cancer therapy, with positive results in the adjuvant treatment of gastric, esophageal, colorectal, breast and lung cancers. These studies have suggested the efficacy of PSK as an immunomodulator of biological responses. The precise molecular mechanisms responsible for its biological activity have yet to be fully elucidated. Methods The in vitro cytotoxic anti-tumour activity of PSK has been evaluated in various tumour cell lines derived from leukaemias, melanomas, fibrosarcomas and cervix, lung, pancreas and gastric cancers. Tumour cell proliferation in vitro was measured by BrdU incorporation and viable cell count. Effect of PSK on human peripheral blood lymphocyte (PBL proliferation in vitro was also analyzed. Studies of cell cycle and apoptosis were performed in PSK-treated cells. Results PSK showed in vitro inhibition of tumour cell proliferation as measured by BrdU incorporation and viable cell count. The inhibition ranged from 22 to 84%. Inhibition mechanisms were identified as cell cycle arrest, with cell accumulation in G0/G1 phase and increase in apoptosis and caspase-3 expression. These results indicate that PSK has a direct cytotoxic activity in vitro, inhibiting tumour cell proliferation. In contrast, PSK shows a synergistic effect with IL-2 that increases PBL proliferation. Conclusion These results indicate that PSK has cytotoxic activity in vitro on tumour cell lines. This new cytotoxic activity of PSK on tumour cells is independent of its previously described immunomodulatory activity on NK cells.

  18. Algerian Propolis Potentiates Doxorubicin Mediated Anticancer Effect against Human Pancreatic PANC-1 Cancer Cell Line through Cell Cycle Arrest, Apoptosis Induction and P-Glycoprotein Inhibition.

    Science.gov (United States)

    Rouibah, Hassiba; Mesbah, Lahouel; Kebsa, Wided; Zihlif, Malek; Ahram, Mamoun; Aburmeleih, Bachaer; Mostafa, Ibtihal; El Amir, Hemzeh

    2018-01-10

    Pancreatic cancer is one of the most aggressive and lethal cancer, with poor prognosis and high resistant to current chemotherapeutic agents. Therefore, new therapeutic strategies and targets are underscored. Propolis has been reported to exhibit a broad spectrum of biological activities including anticancer activity. This study was carried out to assess the possible efficacy of Algerian propolis on the antitumor effect of doxorubicin on human pancreatic cancer cell line (PANC-1). Modifications in cell viability, apoptosis and cell cycle progression, Pgp activity and intracellular accumulation of DOX were monitored to study the synergistic effect of Algerian propolis on the antitumor effects of DOX in PANC-1 cell line. Both propolis and its combination with doxorubicin inhibited cell growth in a dose-dependent manner by inducing cell cycle arrest and apoptosis. In the presence of 100 µg/ml of propolis, the IC50 of DOX against PANC-1 cells decreased by 10.9-fold. Propolis combined with DOX increased after 48h, the number of cells in the G0G1 phase with dramatical increase in sub-G1 phase to reach 47% of total cells, corresponding to an increase of senescence or apoptotic state of the cells. Dead cell assay with annexinV/PI staining demonstrated that propolis and propolis-DOX treatment resulted in a remarkable induction of apoptosis as detected by flow cytometry. It was interesting to note that propolis at its 5IC50 was found as the most potent inducer of apoptosis. Our finding revealed that induced apoptosis in our conditions was caspase-3 and caspase-9 dependent. Flow cytometry showed that propolis increased the accumulation of doxorubicin within PANC-1 cells. Moreover, fluorescent intensity detection revealed that propolis remarkably increased the retention of rhodamine-123, 7-fold compared to 3-fold of verapamil, the most effective P-gp inhibitor. In conclusion, propolis sensitize pancreatic cancer cells to DOX via enhancing the intracellular retention of DOX

  19. Cell cycle regulation by the Wee1 Inhibitor PD0166285, Pyrido [2,3-d] pyimidine, in the B16 mouse melanoma cell line

    International Nuclear Information System (INIS)

    Hashimoto, Osamu; Shinkawa, Masako; Torimura, Takuji; Nakamura, Toru; Selvendiran, Karuppaiyah; Sakamoto, Masaharu; Koga, Hironori; Ueno, Takato; Sata, Michio

    2006-01-01

    Wee1 kinase plays a critical role in maintaining G2 arrest through its inhibitory phosphorylation of cdc2. In previous reports, a pyridopyrimidine molecule PD0166285 was identified to inhibit Wee1 activity at nanomolar concentrations. This G2 checkpoint abrogation by PD0166285 was demonstrated to kill cancer cells, there at a toxic highest dose of 0.5 μM in some cell lines for exposure periods of no longer than 6 hours. The deregulated cell cycle progression may have ultimately damaged the cancer cells. We herein report one of the mechanism by which PD0166285 leads to cell death in the B16 mouse melanoma cell line. Tumor cell proliferation was determined by counting cell numbers. Cell cycle distribution was determined by flow cytometry. Morphogenesis analysis such as microtubule stabilization, Wee1 distribution, and cyclin B location were observed by immunofluorescence confocal microscopy. An immunoblot analysis of cdc2-Tyr15, cyclin D, E, p16, 21, 27, and Rb. A real-time PCR of the mRNA of cyclin D were completed. In our experiment, B16 cells also dramatically abrogated the G2 checkpoint and were found to arrest in the early G1 phase by treatment with 0.5 μM for 4 hours observed by flow cytometry. Cyclin D mRNA decreased within 4 hours observed by Real-time PCR. Rb was dephosphrylated for 24 hours. However, B16 cells did not undergo cell death after 0.5 μM treatment for 24 hours. Immnofluoscence microscopy showed that the cells become round and small in the morphogenesis. More interesting phenomena were that microtubule stabilization was blocked, and Wee1 distribution was restricted after treatment for 4 hours. We analyzed the effect of Wee1 inhibitor PD0166285 described first by Wang in the G2 transition in the B16 melanoma cell line. The inhibitor PD0166285 abrogated G2/M checkpoint inducing early cell division. Moreover, we found that the treatment of cells with the inhibitor is related to microtubule stabilization and decrease in cyclin D transcription

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

    Directory of Open Access Journals (Sweden)

    Qi XL

    2012-04-01

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

  1. Study of the cell cycle control for human malignant mesothelioma lines. Interferon and radiations effect; Etude de la regulation du cycle cellulaire de lignees de mesotheliome malin humain. Effet de l'interferon et des radiations

    Energy Technology Data Exchange (ETDEWEB)

    Vivo, C

    1999-07-01

    In order to better understand the inhibition mechanisms of the IFN-R-HU on tumoral development, the IFN-R-U effect on MM lines has been studied. Three groups of lines has been distinguished: eight sensitive lines, two intermediate and three resistant. The sensitive lines showed a triple locking of the cell cycle: in phases S, G1 and G2. The study of the cell cycle control points function, realized by the MM lines radiation exposure showed the points function on G1/S and-or on G2/M and the dependence or non dependence of the cycle stop of the protein P53 and P21 W at F1/CIP1. (A.L.B.)

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

    DEFF Research Database (Denmark)

    Neave, Antje S.; Sarup, Sussi; Seidelin, Michel

    2005-01-01

    Recent results have shown that indole-3-carbinol (I3C) inhibits the cellular growth of human cancer cell lines. In some cruciferous vegetables, another indole, N-methoxyindole-3-carbinol (NI3C), is found beside I3C. Knowledge about the biological effects of NI3C is limited. The aim of the present...... study was to show the effect of NI3C on cell growth of two human colon cancer cell lines, DLD-1 and HCT-116. For the first time it is shown that NI3C inhibits cellular growth of DLD-1 and HCT-116 and that NI3C is a more potent inhibitor of cell proliferation than I3C. In addition to the inhibition...... of cellular proliferation, NI3C caused an accumulation of HCT-116 cells in the G2/M phase, in contrast to I3C, which led to an accumulation of the colon cells in G0/G1 phase. Furthermore, NI3C delays the G1-S phase transition of synchronized HCT-116 cells. The indole-mediated cell-cycle arrest may be related...

  3. Radiosensitivity of mesothelioma cell lines

    International Nuclear Information System (INIS)

    Haekkinen, A.M.; Laasonen, A.; Linnainmaa, K.; Mattson, K.; Pyrhoenen, S.

    1996-01-01

    The present study was carried out in order to examine the radiosensitivity of malignant pleural mesothelioma cell lines. Cell kinetics, radiation-induced delay of the cell cycle and DNA ploidy of the cell lines were also determined. For comparison an HeLa and a human foetal fibroblast cell line were simultaneously explored. Six previously cytogenetically and histologically characterized mesothelioma tumor cell lines were applied. A rapid tiazolyl blue microtiter (MTT) assay was used to analyze radiosensitivity and cell kinetics and DNA ploidy of the cultured cells were determined by flow cytometry. The survival fraction after a dose of 2 Gy (SF2), parameters α and β of the linear quadratic model (LQ-model) and mean inactivation dose (D MID ) were also estimated. The DNA index of four cell lines equaled 1.0 and two cell lines equaled 1.5 and 1.6. Different mesothelioma cell lines showed a great variation in radiosensitivity. Mean survival fraction after a radiation dose of 2 Gy (SF2) was 0.60 and ranged from 0.36 to 0.81 and mean α value was 0.26 (range 0.48-0.083). The SF2 of the most sensitive diploid mesothelioma cell line was 0.36: Less than that of the foetal fibroblast cell line (0.49). The survival fractions (0.81 and 0.74) of the two most resistant cell lines, which also were aneuploid, were equal to that of the HeLa cell line (0.78). The α/β ratios of the most sensitive cell lines were almost an order of magnitude greater than those of the two most resistant cell lines. Radiation-induced delay of the most resistant aneuploid cell line was similar to that of HeLa cells but in the most sensitive (diploid cells) there was practically no entry into the G1 phase following the 2 Gy radiation dose during 36 h. (orig.)

  4. The cucurbitacins D, E, and I from Ecballium elaterium (L. upregulate the LC3 gene and induce cell-cycle arrest in human gastric cancer cell line AGS

    Directory of Open Access Journals (Sweden)

    Naser Jafargholizadeh

    2018-03-01

    Full Text Available Objective(s: Cucurbitacins exhibit a range of anti-cancer functions. We investigated the effects of cucurbitacins D, E, and I purified from Ecballium elaterium (L. A. Rich fruits on some apoptotic and autophagy genes in human gastric cancer cell line AGS. Materials and Methods: Using quantitative reverse transcription PCR (qRT-PCR, the expression of LC3, VEGF, BAX, caspase-3, and c-MYC genes were quantified in AGS cells 24 hr after treatment with cucurbitacins D, E, and I at concentrations 0.3, 0.1 and 0.5 μg/ml, respectively. Cell cycle and death were analyzed by flowcytometry. Results: Purified cucurbitacins induced sub-G1 cell-cycle arrest and cell death in AGS cells and upregulated LC3mRNA effectively, but showed a very low effect on BAX, caspase-3, and c-MYC mRNA levels. Also after treatment with cucurbitacin I at concentration 0.5 μg/ml, VEGF mRNA levels were increased about 4.4 times. Pairwise comparison of the effect of cucurbitacins D, E, and I on LC3 mRNA expression showed that the cucurbitacin I effect is 1.3 and 1.1 times that of cucurbitacins E and D, respectively; cucurbitacin D effect is 1.2 times that of cucurbitacin E (P-value

  5. Molecular conservation of estrogen-response associated with cell cycle regulation, hormonal carcinogenesis and cancer in zebrafish and human cancer cell lines

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    Govindarajan Kunde R

    2011-05-01

    Full Text Available Abstract Background The zebrafish is recognized as a versatile cancer and drug screening model. However, it is not known whether the estrogen-responsive genes and signaling pathways that are involved in estrogen-dependent carcinogenesis and human cancer are operating in zebrafish. In order to determine the potential of zebrafish model for estrogen-related cancer research, we investigated the molecular conservation of estrogen responses operating in both zebrafish and human cancer cell lines. Methods Microarray experiment was performed on zebrafish exposed to estrogen (17β-estradiol; a classified carcinogen and an anti-estrogen (ICI 182,780. Zebrafish estrogen-responsive genes sensitive to both estrogen and anti-estrogen were identified and validated using real-time PCR. Human homolog mapping and knowledge-based data mining were performed on zebrafish estrogen responsive genes followed by estrogen receptor binding site analysis and comparative transcriptome analysis with estrogen-responsive human cancer cell lines (MCF7, T47D and Ishikawa. Results Our transcriptome analysis captured multiple estrogen-responsive genes and signaling pathways that increased cell proliferation, promoted DNA damage and genome instability, and decreased tumor suppressing effects, suggesting a common mechanism for estrogen-induced carcinogenesis. Comparative analysis revealed a core set of conserved estrogen-responsive genes that demonstrate enrichment of estrogen receptor binding sites and cell cycle signaling pathways. Knowledge-based and network analysis led us to propose that the mechanism involving estrogen-activated estrogen receptor mediated down-regulation of human homolog HES1 followed by up-regulation cell cycle-related genes (human homologs E2F4, CDK2, CCNA, CCNB, CCNE, is highly conserved, and this mechanism may involve novel crosstalk with basal AHR. We also identified mitotic roles of polo-like kinase as a conserved signaling pathway with multiple entry

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

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    Rahman HS

    2014-01-01

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

  7. Increased radiosensitivity of HPV-positive head and neck cancer cell lines due to cell cycle dysregulation and induction of apoptosis

    Energy Technology Data Exchange (ETDEWEB)

    Arenz, Andrea; Ziemann, Frank; Wittig, Andrea; Preising, Stefanie; Engenhart-Cabillic, Rita [Philipps-University, Department of Radiotherapy and Radiooncology, BMFZ - Biomedical Research Center, Marburg (Germany); Mayer, Christina; Wagner, Steffen; Klussmann, Jens-Peter; Wittekindt, Claus [Justus Liebig University, Department of Otorhinolaryngology and Head and Neck Surgery, Giessen (Germany); Dreffke, Kirstin [Philipps-University, Institute for Radiobiology and Molecular Radiooncology, Marburg (Germany)

    2014-09-15

    Human Papillomavirus (HPV)-related head and neck squamous cell carcinoma (HNSCC) respond favourably to radiotherapy as compared to HPV-unrelated HNSCC. We investigated DNA damage response in HPV-positive and HPV-negative HNSCC cell lines aiming to identify mechanisms, which illustrate reasons for the increased sensitivity of HPV-positive cancers of the oropharynx. Radiation response including clonogenic survival, apoptosis, DNA double-strand break (DSB) repair, and cell cycle redistribution in four HPV-positive (UM-SCC-47, UM-SCC-104, 93-VU-147T, UPCI:SCC152) and four HPV-negative (UD-SCC-1, UM-SCC-6, UM-SCC-11b, UT-SCC-33) cell lines was evaluated. HPV-positive cells were more radiosensitive (mean SF2: 0.198 range: 0.22-0.18) than HPV-negative cells (mean SF2: 0.34, range: 0.45-0.27; p = 0.010). Irradiated HPV-positive cell lines progressed faster through S-phase showing a more distinct accumulation in G2/M. The abnormal cell cycle checkpoint activation was accompanied by a more pronounced increase of cell death after x-irradiation and a higher number of residual and unreleased DSBs. The enhanced responsiveness of HPV-related HNSCC to radiotherapy might be caused by a higher cellular radiosensitivity due to cell cycle dysregulation and impaired DNA DSB repair. (orig.) [German] Fuer Patienten mit HPV-assoziierten Kopf-Hals-Tumoren (HNSCC) ist im Vergleich zu Patienten mit nicht-HPV-assoziierten Tumoren ein besseres Ueberleben nach Radiotherapie gesichert. Ziel der Untersuchung war die Identifizierung von Unterschieden in der zellulaeren DNA-Schadensantwort von HPV-positiven und HPV-negativen Zelllinien, wodurch die bereits in Erprobung stehende Deeskalation einer Radiotherapie bei Patienten mit HPV-assoziierten HNSCC durch experimentelle Daten abgesichert werden koennte. Klonogenes Ueberleben, Induktion von Apoptose, DNA-Doppelstrang-Reparatur und Zellzyklusverhalten wurden in vier HPV-positiven (UM-SCC-47, UM-SCC-104, 93-VU-147T, UPCI:SCC152) und vier HPV

  8. Peroxisome proliferator-activated receptors (PPAR) agonists affect cell viability, apoptosis and expression of cell cycle related proteins in cell lines of glial brain tumors

    Czech Academy of Sciences Publication Activity Database

    Straková, N.; Ehrmann, J.; Bartoš, Jan; Malíková, J.; Doležel, Jaroslav; Kolář, Z.

    2005-01-01

    Roč. 52, - (2005), s. 126-136 ISSN 0028-2685 Institutional research plan: CEZ:AV0Z50380511; CEZ:AV0Z5038910 Keywords : PPAR * glioplasma * cell cycle Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 0.731, year: 2005

  9. Radiosensitivity of mesothelioma cell lines

    Energy Technology Data Exchange (ETDEWEB)

    Haekkinen, A.M. [Dept. of Oncology, Univ. Central Hospital, Helsinki (Finland); Laasonen, A. [Dept. of Pathology, Central Hospital of Etelae-Pohjanmaa, Seinaejoki (Finland); Linnainmaa, K. [Dept. of Industrial Hygiene and Toxicology, Inst. of Occupational Health, Helsinki (Finland); Mattson, K. [Dept. Pulmonary Medicine, Univ. Central Hospital, Helsinki (Finland); Pyrhoenen, S. [Dept. of Oncology, Univ. Central Hospital, Helsinki (Finland)

    1996-10-01

    The present study was carried out in order to examine the radiosensitivity of malignant pleural mesothelioma cell lines. Cell kinetics, radiation-induced delay of the cell cycle and DNA ploidy of the cell lines were also determined. For comparison an HeLa and a human foetal fibroblast cell line were simultaneously explored. Six previously cytogenetically and histologically characterized mesothelioma tumor cell lines were applied. A rapid tiazolyl blue microtiter (MTT) assay was used to analyze radiosensitivity and cell kinetics and DNA ploidy of the cultured cells were determined by flow cytometry. The survival fraction after a dose of 2 Gy (SF2), parameters {alpha} and {beta} of the linear quadratic model (LQ-model) and mean inactivation dose (D{sub MID}) were also estimated. The DNA index of four cell lines equaled 1.0 and two cell lines equaled 1.5 and 1.6. Different mesothelioma cell lines showed a great variation in radiosensitivity. Mean survival fraction after a radiation dose of 2 Gy (SF2) was 0.60 and ranged from 0.36 to 0.81 and mean {alpha} value was 0.26 (range 0.48-0.083). The SF2 of the most sensitive diploid mesothelioma cell line was 0.36: Less than that of the foetal fibroblast cell line (0.49). The survival fractions (0.81 and 0.74) of the two most resistant cell lines, which also were aneuploid, were equal to that of the HeLa cell line (0.78). The {alpha}/{beta} ratios of the most sensitive cell lines were almost an order of magnitude greater than those of the two most resistant cell lines. Radiation-induced delay of the most resistant aneuploid cell line was similar to that of HeLa cells but in the most sensitive (diploid cells) there was practically no entry into the G1 phase following the 2 Gy radiation dose during 36 h. (orig.).

  10. Completion of hepatitis C virus replication cycle in heterokaryons excludes dominant restrictions in human non-liver and mouse liver cell lines.

    Directory of Open Access Journals (Sweden)

    Anne Frentzen

    2011-04-01

    Full Text Available Hepatitis C virus (HCV is hepatotropic and only infects humans and chimpanzees. Consequently, an immunocompetent small animal model is lacking. The restricted tropism of HCV likely reflects specific host factor requirements. We investigated if dominant restriction factors expressed in non-liver or non-human cell lines inhibit HCV propagation thus rendering these cells non-permissive. To this end we explored if HCV completes its replication cycle in heterokaryons between human liver cell lines and non-permissive cell lines from human non-liver or mouse liver origin. Despite functional viral pattern recognition pathways and responsiveness to interferon, virus production was observed in all fused cells and was only ablated when cells were treated with exogenous interferon. These results exclude that constitutive or virus-induced expression of dominant restriction factors prevents propagation of HCV in these cell types, which has important implications for HCV tissue and species tropism. In turn, these data strongly advocate transgenic approaches of crucial human HCV cofactors to establish an immunocompetent small animal model.

  11. Multiparameter Cell Cycle Analysis.

    Science.gov (United States)

    Jacobberger, James W; Sramkoski, R Michael; Stefan, Tammy; Woost, Philip G

    2018-01-01

    Cell cycle cytometry and analysis are essential tools for studying cells of model organisms and natural populations (e.g., bone marrow). Methods have not changed much for many years. The simplest and most common protocol is DNA content analysis, which is extensively published and reviewed. The next most common protocol, 5-bromo-2-deoxyuridine S phase labeling detected by specific antibodies, is also well published and reviewed. More recently, S phase labeling using 5'-ethynyl-2'-deoxyuridine incorporation and a chemical reaction to label substituted DNA has been established as a basic, reliable protocol. Multiple antibody labeling to detect epitopes on cell cycle regulated proteins, which is what this chapter is about, is the most complex of these cytometric cell cycle assays, requiring knowledge of the chemistry of fixation, the biochemistry of antibody-antigen reactions, and spectral compensation. However, because this knowledge is relatively well presented methodologically in many papers and reviews, this chapter will present a minimal Methods section for one mammalian cell type and an extended Notes section, focusing on aspects that are problematic or not well described in the literature. Most of the presented work involves how to segment the data to produce a complete, progressive, and compartmentalized cell cycle analysis from early G1 to late mitosis (telophase). A more recent development, using fluorescent proteins fused with proteins or peptides that are degraded by ubiquitination during specific periods of the cell cycle, termed "Fucci" (fluorescent, ubiquitination-based cell cycle indicators) provide an analysis similar in concept to multiple antibody labeling, except in this case cells can be analyzed while living and transgenic organisms can be created to perform cell cycle analysis ex or in vivo (Sakaue-Sawano et al., Cell 132:487-498, 2007). This technology will not be discussed.

  12. Ethanol extract of Kilkyung-baeksan, a traditional herbal formula, induces G0/G1 cell cycle arrest in human lung cancer cell lines

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    Jinhee Kim

    2015-09-01

    Conclusion: EE-KKBS exerted its cytostatic activity through regulating G1 cell cycle checkpoint in lung cancer cells, and this activity is mainly mediated by one of its component herbs, seeds of Croton tiglium. Collectively, our data suggest that EE-KKBS could be a novel candidate for adjuvant therapy for lung cancer.

  13. Capilliposide Isolated from Lysimachia capillipes Hemsl. Induces ROS Generation, Cell Cycle Arrest, and Apoptosis in Human Nonsmall Cell Lung Cancer Cell Lines

    Directory of Open Access Journals (Sweden)

    Zheng-hua Fei

    2014-01-01

    Full Text Available Several data has reported that capilliposide, extracted from a traditional Chinese medicine, Lysimachia capillipes Hemsl. (LC could exhibit inhibitory effect on cell proliferation in various cancers. The current study investigated the antitumor efficacy of Capilliposide and elucidated its potential molecular mechanism involved in vivo and vitro. Our results indicated that LC capilliposide inhibited proliferation of lung cancer cells in a dose-dependent manner. LC capilliposide induced cell cycle arrest at the S stage and enhanced apoptosis in NSCLC cells. Treatment with LC capilliposide increased the intracellular level of ROS, which activated the mitochondrial apoptotic pathway. Blockage of ROS by NAC highly reversed the effect of LC capilliposide on apoptosis. Xenograft tumor growth was significantly lower in the LC-treated group compared with the untreated control group (P<0.05. The results also show that LC treatment does not produce any overt signs of acute toxicity in vivo. These findings demonstrate that LC capilliposide could exert an anti-tumor effect on NSCLC through mitochondrial-mediated apoptotic pathway and the activation of ROS is involved.

  14. Molecular mechanisms of celery seed extract induced apoptosis via s phase cell cycle arrest in the BGC-823 human stomach cancer cell line.

    Science.gov (United States)

    Gao, Lin-Lin; Feng, Lei; Yao, Shu-Tong; Jiao, Peng; Qin, Shu-Cun; Zhang, Wei; Zhang, Ya-Bin; Li, Fu-Rong

    2011-01-01

    Mechanisms of apoptosis in tumor cells is an important field of tumor therapy and cancer molecular biology. Loss of cell cycle control, leading to uncontrolled proliferation, is common in cancer. Therefore, the identification of potent and selective cyclin dependent kinase inhibitors is a priority for anti-cancer drug discovery. There are at least two major apoptotic pathways, initiated by caspase-8 and caspase-9, respectively, which can activate caspase cascades. Apoptosis triggered by activation of the mitochondrial-dependent caspase pathway represents the main programmed cell death mechanism. This is activated by various intracellular stresses that induce permeabilization of the mitochondrial membrane. Anti-tumor effects of celery seed extract (CSE) and related mechanisms regarding apoptosis were here investigated in human gastric cancer BGC-823 cells. CSE was produced by supercritical fluid extraction. Cell viability was analyzed by 3-(4,5-dimethylthiazol-2-yl)- 2,5-diphenyl-tetrazolium bromide (MTT) assay and apoptosis by flow cytometry using Annexin/PI staining and DAPI staining and a laser scanning confocal microscope (LSCM). Cell cycling was evaluated using PI staining with flow cytometry and expression of cell cycle and apoptosis-related proteins cyclin A, CDK2, bcl-2 and bax was assessed by immunohistochemical staining. CSE had an anti-proliferation effect on human gastric cancer BGC-823 cells in a dose- and time-dependent manner. After treatment, the apoptotic rate significantly increased, with morphological changes typical of apoptosis observed with LSCM by DAPI staining. Cell cycle and apoptosis related proteins, such as cyclin A, CDK2 and bcl-2 were all down-regulated, whereas bax was up-regulated. The molecular determinants of inhibition of cell proliferation as well as apoptosis of CSE may be associated with cycle arrest in the S phase.

  15. Eco-Friendly Formulated Zinc Oxide Nanoparticles: Induction of Cell Cycle Arrest and Apoptosis in the MCF-7 Cancer Cell Line.

    Science.gov (United States)

    Boroumand Moghaddam, Amin; Moniri, Mona; Azizi, Susan; Abdul Rahim, Raha; Bin Ariff, Arbakariya; Navaderi, Mohammad; Mohamad, Rosfarizan

    2017-10-20

    Green products have strong potential in the discovery and development of unique drugs. Zinc oxide nanoparticles (ZnO NPs) have been observed to have powerful cytotoxicity against cells that cause breast cancer. The present study aims to examine the cell cycle profile, status of cell death, and pathways of apoptosis in breast cancer cells (MCF-7) treated with biosynthesized ZnO NPs. The anti-proliferative activity of ZnO NPs was determined using MTT assay. Cell cycle analysis and the mode of cell death were evaluated using a flow cytometry instrument. Quantitative real-time-PCR (qRT-PCR) was employed to investigate the expression of apoptosis in MCF-7 cells. ZnO NPs were cytotoxic to the MCF-7 cells in a dose-dependent manner. The 50% growth inhibition concentration (IC 50 ) of ZnO NPs at 24 h was 121 µg/mL. Cell cycle analysis revealed that ZnO NPs induced sub-G₁ phase (apoptosis), with values of 1.87% at 0 μg/mL (control), 71.49% at IC 25 , 98.91% at IC 50 , and 99.44% at IC 75 . Annexin V/propidium iodide (PI) flow cytometry analysis confirmed that ZnO NPs induce apoptosis in MCF-7 cells. The pro-apoptotic genes p53 , p21 , Bax , and JNK were upregulated, whereas anti-apoptotic genes Bcl-2 , AKT1 , and ERK1/2 were downregulated in a dose-dependent manner. The arrest and apoptosis of MCF-7 cells were induced by ZnO NPs through several signalling pathways.

  16. A change in the oxygen effect throughout the cell-cycle of human cells of the line NHIK 3025 cultivated in vitro

    International Nuclear Information System (INIS)

    Pettersen, E.O.; Christensen, T.; Bakke, O.; Oftebro, R.

    1977-01-01

    NHIK 3025 cells were synchronized by repeated mitotic selection. The S-phase was determined by 3 H-thymidine incorporation and scintillation counting. By comparing the age-response curves of aerobic cells irradiated with 500 rad with those of extremely hypoxic ( 2 ) cells irradiated with 1500 rad, it was found that the sensitizing effect of oxygen was not constant throughout the cycle. It was significantly higher in S, G2 and mitosis than in G1. No significant sensitizing effect of 120 p.p.m. O 2 (compared with 2 ) was found on cells in G1 when the cells were irradiated with 1500 rad. In S, G2 and mitosis, however, the sensitizing effect of oxygen at 120 p.p.m was considered to be significant. Experiment performed with cells irradiated with 2000 rad in contact with either 2 or 80 p.p.m. O 2 showed the same trend, little sensitizing effect in G1 and higher in S, G2 and mitosis. Dose-response curves for cells in mid-G1 and mid-S under aerobic and extremely hypoxic conditions were well fitted by the formula S = exp (-αD-βD 2 ). From the dose-response curves it was concluded that the change in the sensitizing effect of oxygen throughout the cell-cycle only appeared for low doses (in the dose region where α dominates). The sensitizing effect of oxygen on cells in mid-G1 was found to be increasing with increasing dose. (author)

  17. 125I brachytherapy of locally advanced non-small-cell lung cancer after one cycle of first-line chemotherapy:a comparison with best supportive care

    Directory of Open Access Journals (Sweden)

    Song J

    2017-03-01

    Full Text Available Jingjing Song* Xiaoxi Fan* Zhongwei Zhao* Minjiang Chen* Weiqian Chen, Fazong Wu, Dengke Zhang, Li Chen, Jianfei Tu, Jiansong Ji Department of Interventional Radiology, Zhejiang University Lishui Hospital, The Fifth Affiliated Hospital of Wenzhou Medical University, Lishui Central Hospital, Lishui, Zhejiang, People’s Republic of China *These authors have contributed equally to this work Objectives: The objective of this study was to assess the efficacy of computed tomography (CT-guided 125I brachytherapy alone in improving the survival and quality of life of patients with unresectable locally advanced non-small-cell lung cancer (NSCLC after one cycle of first-line chemotherapy.Patients and methods: Sixteen patients with locally advanced NSCLC were treated with CT-guided 125I brachytherapy after one cycle of first-line chemotherapy (group A. Sixteen patients who received only best supportive care (group B were matched up with the patients in group A. Primary end point included survival, and secondary end point included assessment of safety, effectiveness of CT-guided 125I brachytherapy, and improvement in the quality of life.Results: The two groups were well balanced in terms of age, disease histology, tumor stage, tumor location, and performance status (P>0.05. The median follow-up time was 16 months (range, 3–30. The total tumor response rate was 75.0% in group A, which was significantly higher than that in group B (0.0% (P<0.01. The median progression-free survival time was 4.80 months for patients in group A and 1.35 months for patients in group B (P<0.001. Kaplan–Meier survival analysis showed that the median survival time of group A was 9.4±0.3 months versus 8.4±0.1 months in group B (P=0.013. Tumor-related symptoms of patients were significantly relieved, and the quality of life was markedly improved in group A than in group B.Conclusion: CT-guided 125I brachytherapy improved the survival of patients with locally advanced

  18. Arctigenin anti-tumor activity in bladder cancer T24 cell line through induction of cell-cycle arrest and apoptosis.

    Science.gov (United States)

    Yang, Shucai; Ma, Jing; Xiao, Jianbing; Lv, Xiaohong; Li, Xinlei; Yang, Huike; Liu, Ying; Feng, Sijia; Zhang, Yafang

    2012-08-01

    Bladder cancer is the most common neoplasm in the urinary system. This study assesses arctigenin anti-tumor activity in human bladder cancer T24 cells in vitro and the underlying molecular events. The flow cytometry analysis was used to detect cell-cycle distribution and apoptosis. Western blotting was used to detect changes in protein expression. The data showed that arctigenin treatment reduced viability of bladder cancer T24 cells in a dose- and time-dependent manner after treatment with arctigenin (10, 20, 40, 80, and 100 μmol/L) for 24 hr and 48 hr. Arctigenin treatment clearly arrested tumor cells in the G1 phase of the cell cycle. Apoptosis was detected by hoechst stain and flow cytometry after Annexin-V-FITC/PI double staining. Early and late apoptotic cells were accounted for 2.32-7.01% and 3.07-7.35%, respectively. At the molecular level, arctigenin treatment decreased cyclin D1 expression, whereas CDK4 and CDK6 expression levels were unaffected. Moreover, arctigenin selectively altered the phosphorylation of members of the MAPK superfamily, decreasing phosphorylation of ERK1/2 and activated phosphorylation of p38 significantly in a dose-dependent manner. These results suggest that arctigenin may inhibit cell viability and induce apoptosis by direct activation of the mitochondrial pathway, and the mitogen-activated protein kinase pathway may play an important role in the anti-tumor effect of arctigenin. The data from the current study demonstrate the usefulness of arctigenin in bladder cancer T24 cells, which should further be evaluated in vivo before translation into clinical trials for the chemoprevention of bladder cancer. Copyright © 2012 Wiley Periodicals, Inc.

  19. Over-expression and siRNA of a novel environmental lipopolysaccharide-responding gene on the cell cycle of the human hepatoma-derived cell line HepG2

    International Nuclear Information System (INIS)

    Du Kejun; Chai Yubo; Hou Lichao; Chang Wenhui; Chen Suming; Luo Wenjing; Cai Tongjian; Zhang Xiaonan; Chen Nanchun; Chen Yaoming; Chen Jingyuan

    2008-01-01

    Lipopolysaccharide (LPS) is the toxic determinant for Gram-negative bacterium infection. The individual response to LPS was related to its gene background. It is necessary to identify new molecules and signaling transduction pathways about LPS. The present study was undertaken to evaluate the effects of a novel environmental lipopolysaccharide-responding (Elrg) gene on the regulation of proliferation and cell cycle of the hepatoma-derived cell line, HepG2. By means of RT-PCR, the new molecule of Elrg was generated from a human dental pulp cell cDNA library. Expression level of Elrg in HepG2 cells was remarkably upgraded by the irritation of LPS. Localization of Elrg in HepG2 cells was positioned mainly in cytoplasm. HepG2 cells were markedly arrested in the G1 phase by over-expressing Elrg. The percentage of HepG2 cells in G1 phase partly decreased after Elrg-siRNA. In conclusion, Elrg is probably correlative with LPS responding. Elrg is probably a new protein in cytoplasm which plays an important role in regulating cell cycle. The results will deepen our understanding about the potential effects of Elrg on the human hepatoma-derived cell line HepG2

  20. An antioxidant extract of tropical lichen, Parmotrema reticulatum, induces cell cycle arrest and apoptosis in breast carcinoma cell line MCF-7.

    Directory of Open Access Journals (Sweden)

    Nikhil Baban Ghate

    Full Text Available This report highlights the phytochemical analysis, antioxidant potential and anticancer activity against breast carcinoma of 70% methanolic extract of lichen, Parmotrema reticulatum (PRME. Phytochemical analysis of PRME confirms the presence of various phytoconstituents like alkaloids, carbohydrates, flavonoids, glycosides, phenols, saponins, tannins, anthraquinones, and ascorbic acid; among which alkaloids, phenols and flavonoids are found in abundant amount. High performance liquid chromatography (HPLC analysis of PRME revealed the presence of catechin, purpurin, tannic acid and reserpine. Antioxidant activity was evaluated by nine separate methods. PRME showed excellent hydroxyl and hypochlorous radical scavenging as well as moderate DPPH, superoxide, singlet oxygen, nitric oxide and peroxynitrite scavenging activity. Cytotoxicity of PRME was tested against breast carcinoma (MCF-7, lung carcinoma (A549 and normal lung fibroblast (WI-38 using WST-1 method. PRME was found cytotoxic against MCF-7 cells with an IC50 value 130.03 ± 3.11 µg/ml while negligible cytotoxicity was observed on A549 and WI-38 cells. Further flow cytometric study showed that PRME halted the MCF-7 cells in S and G2/M phases and induces apoptosis in dose as well as time dependent manner. Cell cycle arrest was associated with downregulation of cyclin B1, Cdk-2 and Cdc25C as well as slight decrease in the expression of Cdk-1 and cyclin A1 with subsequent upregulation of p53 and p21. Moreover PRME induced Bax and inhibited Bcl-2 expression, which results in increasing Bax/Bcl-2 ratio and activation of caspase cascade. This ultimately leads to PARP degradation and induces apoptosis in MCF-7 cells. It can be hypothesised from the current study that the antioxidant and anticancer potential of the PRME may reside in the phytoconstitutents present in it and therefore, PRME may be used as a possible source of natural antioxidant that may be developed to an anticancer agent.

  1. Cytotoxicity and cell cycle arrest induced by andrographolide lead to programmed cell death of MDA-MB-231 breast cancer cell line.

    Science.gov (United States)

    Banerjee, Malabika; Chattopadhyay, Subrata; Choudhuri, Tathagata; Bera, Rammohan; Kumar, Sanjay; Chakraborty, Biswajit; Mukherjee, Samir Kumar

    2016-04-16

    Breast cancer is considered as an increasing major life-threatening concern among the malignancies encountered globally in females. Traditional therapy is far from satisfactory due to drug resistance and various side effects, thus a search for complementary/alternative medicines from natural sources with lesser side effects is being emphasized. Andrographis paniculata, an oriental, traditional medicinal herb commonly available in Asian countries, has a long history of treating a variety of diseases, such as respiratory infection, fever, bacterial dysentery, diarrhea, inflammation etc. Extracts of this plant showed a wide spectrum of therapeutic effects, such as anti-bacterial, anti-malarial, anti-viral and anti-carcinogenic properties. Andrographolide, a diterpenoid lactone, is the major active component of this plant. This study reports on andrographolide induced apoptosis and its possible mechanism in highly proliferative, invasive breast cancer cells, MDA-MB-231 lacking a functional p53 and estrogen receptor (ER). Furthermore, the pharmacokinetic properties of andrographolide have also been studied in mice following intravenous and oral administration. Andrographolide showed a time- and concentration- dependent inhibitory effect on MDA-MB-231 breast cancer cell proliferation, but the treatment did not affect normal breast epithelial cells, MCF-10A (>80 %). The number of cells in S as well as G2/M phase was increased after 36 h of treatment. Elevated reactive oxygen species (ROS) production with concomitant decrease in Mitochondrial Membrane Potential (MMP) and externalization of phosphatidyl serine were observed. Flow cytometry with Annexin V revealed that the population of apoptotic cells increased with prolonged exposure to andrographolide. Activation of caspase-3 and caspase-9 were also noted. Bax and Apaf-1 expression were notably increased with decreased Bcl-2 and Bcl-xL expression in andrographolide-treated cells. Pharmacokinetic study with andrographolide

  2. Fluoroquinolone-mediated inhibition of cell growth, S-G2/M cell cycle arrest, and apoptosis in canine osteosarcoma cell lines.

    Science.gov (United States)

    Seo, Kyoung won; Holt, Roseline; Jung, Yong-Sam; Rodriguez, Carlos O; Chen, Xinbin; Rebhun, Robert B

    2012-01-01

    Despite significant advancements in osteosarcoma research, the overall survival of canine and human osteosarcoma patients has remained essentially static over the past 2 decades. Post-operative limb-spare infection has been associated with improved survival in both species, yet a mechanism for improved survival has not been clearly established. Given that the majority of canine osteosarcoma patients experiencing post-operative infections were treated with fluoroquinolone antibiotics, we hypothesized that fluoroquinolone antibiotics might directly inhibit the survival and proliferation of canine osteosarcoma cells. Ciprofloxacin or enrofloxacin were found to inhibit p21(WAF1) expression resulting in decreased proliferation and increased S-G(2)/M accumulation. Furthermore, fluoroquinolone exposure induced apoptosis of canine osteosarcoma cells as demonstrated by cleavage of caspase-3 and PARP, and activation of caspase-3/7. These results support further studies examining the potential impact of quinolones on survival and proliferation of osteosarcoma.

  3. Fluoroquinolone-mediated inhibition of cell growth, S-G2/M cell cycle arrest, and apoptosis in canine osteosarcoma cell lines.

    Directory of Open Access Journals (Sweden)

    Kyoung won Seo

    Full Text Available Despite significant advancements in osteosarcoma research, the overall survival of canine and human osteosarcoma patients has remained essentially static over the past 2 decades. Post-operative limb-spare infection has been associated with improved survival in both species, yet a mechanism for improved survival has not been clearly established. Given that the majority of canine osteosarcoma patients experiencing post-operative infections were treated with fluoroquinolone antibiotics, we hypothesized that fluoroquinolone antibiotics might directly inhibit the survival and proliferation of canine osteosarcoma cells. Ciprofloxacin or enrofloxacin were found to inhibit p21(WAF1 expression resulting in decreased proliferation and increased S-G(2/M accumulation. Furthermore, fluoroquinolone exposure induced apoptosis of canine osteosarcoma cells as demonstrated by cleavage of caspase-3 and PARP, and activation of caspase-3/7. These results support further studies examining the potential impact of quinolones on survival and proliferation of osteosarcoma.

  4. Cytotoxicity and Proapoptotic Effects of Allium atroviolaceum Flower Extract by Modulating Cell Cycle Arrest and Caspase-Dependent and p53-Independent Pathway in Breast Cancer Cell Lines

    Directory of Open Access Journals (Sweden)

    Somayeh Khazaei

    2017-01-01

    Full Text Available Breast cancer is the second leading cause of cancer death among women and despite significant advances in therapy, it remains a critical health problem worldwide. Allium atroviolaceum is an herbaceous plant, with limited information about the therapeutic capability. We aimed to study the anticancer effect of flower extract and the mechanisms of action in MCF-7 and MDA-MB-231. The extract inhibits the proliferation of the cells in a time- and dose-dependent manner. The underlying mechanism involved the stimulation of S and G2/M phase arrest in MCF-7 and S phase arrest in MDA-MB-231 associated with decreased level of Cdk1, in a p53-independent pathway. Furthermore, the extract induces apoptosis in both cell lines, as indicated by the percentage of sub-G0 population, the morphological changes observed by phase contrast and fluorescent microscopy, and increase in Annexin-V-positive cells. The apoptosis induction was related to downregulation of Bcl-2 and also likely to be caspase-dependent. Moreover, the combination of the extract and tamoxifen exhibits synergistic effect, suggesting that it can complement current chemotherapy. LC-MS analysis displayed 17 major compounds in the extract which might be responsible for the observed effects. Overall, this study demonstrates the potential applications of Allium atroviolaceum extract as an anticancer drug for breast cancer treatment.

  5. CLO : The cell line ontology

    NARCIS (Netherlands)

    Sarntivijai, Sirarat; Lin, Yu; Xiang, Zuoshuang; Meehan, Terrence F.; Diehl, Alexander D.; Vempati, Uma D.; Schuerer, Stephan C.; Pang, Chao; Malone, James; Parkinson, Helen; Liu, Yue; Takatsuki, Terue; Saijo, Kaoru; Masuya, Hiroshi; Nakamura, Yukio; Brush, Matthew H.; Haendel, Melissa A.; Zheng, Jie; Stoeckert, Christian J.; Peters, Bjoern; Mungall, Christopher J.; Carey, Thomas E.; States, David J.; Athey, Brian D.; He, Yongqun

    2014-01-01

    Background: Cell lines have been widely used in biomedical research. The community-based Cell Line Ontology (CLO) is a member of the OBO Foundry library that covers the domain of cell lines. Since its publication two years ago, significant updates have been made, including new groups joining the CLO

  6. Efecto de extractos de la esponja calcarea Leucetta aff. floridana sobre el ciclo de líneas celulares leucemoides Effect of extracts from the calcareous sponge Leucetta aff. floridana on the cell cycle of leukemoid cell lines

    Directory of Open Access Journals (Sweden)

    Diana Margarita Márquez Fernández

    2012-12-01

    .Introduction: Leucetta aff. floridana sponge produces compounds with differential antiproliferative activity on lung and breast cancer. Nevertheless, this activity in other tumour cell lines has not yet been tested and it remains unknown whether its antiproliferative potential is correlated with the cell progression through cell cycle or not. Objective: To evaluate the antiproliferative and anticlonogenic potential and the effect of methanolic and hexanic extracts of sponge L. aff. floridana from the Colombian Caribbean region on the cell cycle of Jurkat and K562 leukemoid cell lines. Methods: The viability and antiproliferative effect were determined using trypan blue assay at 0, 24, 48, 72 and 96 hours. Clongenicity and effect on cell cycle were assayed at 10 and 100 µg/mL Data obtained were analyzed using multifactorial ANOVA and Tukey's test. Results: The hexanic extract presented antiproliferative activity in both Jurkat and K652 cell lines; Jurkat being more sensitive than K652. These results were confirmed by clongenicity assays. The hexanic extract also showed its effect on the dose-dependent accumulation of Sub-G1 cells, although it was different in the two cell lines. The duration of the treatment with the hexanic extract was not significant for K562 cell line, but it was for Jurkat cells. Additionally, the percentage of cell accumulation in Sub-G1 was higher in K562 than in Jurkat cells. The methanolic extract showed antiproliferative effect similar to that of the hexanic extract, but more potent at the lowest concentration (10 µg/mL in K652 cell line clonegenicity. The effect on cell cycle was also similar to that of the hexanic extract, but in this case the duration of treatment was not significant in the cell accumulation in Sub-G1. Conclusions: Altogether these results show the differential potential of the extracts on the cell cycle of the evaluated leukemoid cell lines.

  7. Cell Cycle Control by PTEN.

    Science.gov (United States)

    Brandmaier, Andrew; Hou, Sheng-Qi; Shen, Wen H

    2017-07-21

    Continuous and error-free chromosome inheritance through the cell cycle is essential for genomic stability and tumor suppression. However, accumulation of aberrant genetic materials often causes the cell cycle to go awry, leading to malignant transformation. In response to genotoxic stress, cells employ diverse adaptive mechanisms to halt or exit the cell cycle temporarily or permanently. The intrinsic machinery of cycling, resting, and exiting shapes the cellular response to extrinsic stimuli, whereas prevalent disruption of the cell cycle machinery in tumor cells often confers resistance to anticancer therapy. Phosphatase and tensin homolog (PTEN) is a tumor suppressor and a guardian of the genome that is frequently mutated or deleted in human cancer. Moreover, it is increasingly evident that PTEN deficiency disrupts the fundamental processes of genetic transmission. Cells lacking PTEN exhibit cell cycle deregulation and cell fate reprogramming. Here, we review the role of PTEN in regulating the key processes in and out of cell cycle to optimize genomic integrity. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Cell growth and division cycle

    International Nuclear Information System (INIS)

    Darzynkiewicz, Z.

    1986-01-01

    The concept of the cell cycle in its present form was introduced more than three decades ago. Studying incorporation of DNA precursors by autoradiography, these authors observed that DNA synthesis in individual cells was discontinuous and occupied a discrete portion of the cell life (S phase). Mitotic division was seen to occur after a certain period of time following DNA replication. A distinct time interval between mitosis and DNA replication was also apparent. Thus, the cell cycle was subdivided into four consecutive phases, G/sub 1/, S, G/sub 2/, and M. The G/sub 1/ and G/sub 2/ phases represented the ''gaps'' between mitosis and the start of DNA replication, and between the end of DNA replication and the onset of mitosis, respectively. The cell cycle was defined as the interval between the midpoint of mitosis and the midpoint of the subsequent mitosis of the daughter cell(s). The authors' present knowledge on the cell cycle benefited mostly from the development of four different techniques: autoradiography, time-lapse cinematography, cell synchronization and flow cytometry. Of these, autoradiography has been the most extensively used, especially during the past two decades. By providing a means to analyse incorporation of precursors of DNA, RNA or proteins by individual cells and, in combination with various techniques of cell synchronization, autoradiography yielded most of the data fundamental to the current understanding of the cell cycle-related phenomena. Kinetics of cell progression through the cell cycle could be analysed in great detail after development of such sophisticated autoradiographic approaches as measurements of the fraction of labeled mitoses (''FLM curves'') or multiple sequential cell labelling with /sup 3/H- and /sup 14/C-TdR

  9. Alteration of cell cycle progression by Sindbis virus infection

    Energy Technology Data Exchange (ETDEWEB)

    Yi, Ruirong; Saito, Kengo [Department of Molecular Virology, Graduate School of Medicine, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chiba 260-8670 (Japan); Isegawa, Naohisa [Laboratory Animal Center, Graduate School of Medicine, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chiba 260-8670 (Japan); Shirasawa, Hiroshi, E-mail: sirasawa@faculty.chiba-u.jp [Department of Molecular Virology, Graduate School of Medicine, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chiba 260-8670 (Japan)

    2015-07-10

    We examined the impact of Sindbis virus (SINV) infection on cell cycle progression in a cancer cell line, HeLa, and a non-cancerous cell line, Vero. Cell cycle analyses showed that SINV infection is able to alter the cell cycle progression in both HeLa and Vero cells, but differently, especially during the early stage of infection. SINV infection affected the expression of several cell cycle regulators (CDK4, CDK6, cyclin E, p21, cyclin A and cyclin B) in HeLa cells and caused HeLa cells to accumulate in S phase during the early stage of infection. Monitoring SINV replication in HeLa and Vero cells expressing cell cycle indicators revealed that SINV which infected HeLa cells during G{sub 1} phase preferred to proliferate during S/G{sub 2} phase, and the average time interval for viral replication was significantly shorter in both HeLa and Vero cells infected during G{sub 1} phase than in cells infected during S/G{sub 2} phase. - Highlights: • SINV infection was able to alter the cell cycle progression of infected cancer cells. • SINV infection can affect the expression of cell cycle regulators. • SINV infection exhibited a preference for the timing of viral replication among the cell cycle phases.

  10. Alteration of cell cycle progression by Sindbis virus infection

    International Nuclear Information System (INIS)

    Yi, Ruirong; Saito, Kengo; Isegawa, Naohisa; Shirasawa, Hiroshi

    2015-01-01

    We examined the impact of Sindbis virus (SINV) infection on cell cycle progression in a cancer cell line, HeLa, and a non-cancerous cell line, Vero. Cell cycle analyses showed that SINV infection is able to alter the cell cycle progression in both HeLa and Vero cells, but differently, especially during the early stage of infection. SINV infection affected the expression of several cell cycle regulators (CDK4, CDK6, cyclin E, p21, cyclin A and cyclin B) in HeLa cells and caused HeLa cells to accumulate in S phase during the early stage of infection. Monitoring SINV replication in HeLa and Vero cells expressing cell cycle indicators revealed that SINV which infected HeLa cells during G 1 phase preferred to proliferate during S/G 2 phase, and the average time interval for viral replication was significantly shorter in both HeLa and Vero cells infected during G 1 phase than in cells infected during S/G 2 phase. - Highlights: • SINV infection was able to alter the cell cycle progression of infected cancer cells. • SINV infection can affect the expression of cell cycle regulators. • SINV infection exhibited a preference for the timing of viral replication among the cell cycle phases

  11. The In Vivo DNA Binding Properties of Wild-Type and Mutant p53 Proteins in Mammary Cell Lines During the Course of Cell Cycle.

    Science.gov (United States)

    1996-08-01

    that my statement of work (SOW) for the current project omitted many of the tasks that had to be carried out in order to get the lab up and running...that we knew that we could stabilize wild-type p53 in ML-1 cells along with the possibility of being able to get an excellent elutriation profile with...nuclear protein extract was immunoprecipitated with PAb421 cross-linked to ProteinA -Sepharose beads and analysed by SDS-PAGE Western blot analysis with

  12. Lobaplatin arrests cell cycle progression in human hepatocellular carcinoma cells

    Directory of Open Access Journals (Sweden)

    Chen Chang-Jie

    2010-10-01

    Full Text Available Abstract Background Hepatocellular carcinoma (HCC still is a big burden for China. In recent years, the third-generation platinum compounds have been proposed as potential active agents for HCC. However, more experimental and clinical data are warranted to support the proposal. In the present study, the effect of lobaplatin was assessed in five HCC cell lines and the underlying molecular mechanisms in terms of cell cycle kinetics were explored. Methods Cytotoxicity of lobaplatin to human HCC cell lines was examined using MTT cell proliferation assay. Cell cycle distribution was determined by flow cytometry. Expression of cell cycle-regulated genes was examined at both the mRNA (RT-PCR and protein (Western blot levels. The phosphorylation status of cyclin-dependent kinases (CDKs and retinoblastoma (Rb protein was also examined using Western blot analysis. Results Lobaplatin inhibited proliferation of human HCC cells in a dose-dependent manner. For the most sensitive SMMC-7721 cells, lobaplatin arrested cell cycle progression in G1 and G2/M phases time-dependently which might be associated with the down-regulation of cyclin B, CDK1, CDC25C, phosphorylated CDK1 (pCDK1, pCDK4, Rb, E2F, and pRb, and the up-regulation of p53, p21, and p27. Conclusion Cytotoxicity of lobaplatin in human HCC cells might be due to its ability to arrest cell cycle progression which would contribute to the potential use of lobaplatin for the management of HCC.

  13. Difference in membrane repair capacity between cancer cell lines and a normal cell line

    DEFF Research Database (Denmark)

    Frandsen, Stine Krog; McNeil, Anna K.; Novak, Ivana

    2016-01-01

    repair was investigated by disrupting the plasma membrane using laser followed by monitoring fluorescent dye entry over time in seven cancer cell lines, an immortalized cell line, and a normal primary cell line. The kinetics of repair in living cells can be directly recorded using this technique...... cancer cell lines (p immortalized cell line (p

  14. Cell-cycle inhibition by Helicobacter pylori L-asparaginase.

    Directory of Open Access Journals (Sweden)

    Claudia Scotti

    Full Text Available Helicobacter pylori (H. pylori is a major human pathogen causing chronic gastritis, peptic ulcer, gastric cancer, and mucosa-associated lymphoid tissue lymphoma. One of the mechanisms whereby it induces damage depends on its interference with proliferation of host tissues. We here describe the discovery of a novel bacterial factor able to inhibit the cell-cycle of exposed cells, both of gastric and non-gastric origin. An integrated approach was adopted to isolate and characterise the molecule from the bacterial culture filtrate produced in a protein-free medium: size-exclusion chromatography, non-reducing gel electrophoresis, mass spectrometry, mutant analysis, recombinant protein expression and enzymatic assays. L-asparaginase was identified as the factor responsible for cell-cycle inhibition of fibroblasts and gastric cell lines. Its effect on cell-cycle was confirmed by inhibitors, a knockout strain and the action of recombinant L-asparaginase on cell lines. Interference with cell-cycle in vitro depended on cell genotype and was related to the expression levels of the concurrent enzyme asparagine synthetase. Bacterial subcellular distribution of L-asparaginase was also analysed along with its immunogenicity. H. pylori L-asparaginase is a novel antigen that functions as a cell-cycle inhibitor of fibroblasts and gastric cell lines. We give evidence supporting a role in the pathogenesis of H. pylori-related diseases and discuss its potential diagnostic application.

  15. Segmentation and classification of cell cycle phases in fluorescence imaging.

    Science.gov (United States)

    Ersoy, Ilker; Bunyak, Filiz; Chagin, Vadim; Cardoso, M Christina; Palaniappan, Kannappan

    2009-01-01

    Current chemical biology methods for studying spatiotemporal correlation between biochemical networks and cell cycle phase progression in live-cells typically use fluorescence-based imaging of fusion proteins. Stable cell lines expressing fluorescently tagged protein GFP-PCNA produce rich, dynamically varying sub-cellular foci patterns characterizing the cell cycle phases, including the progress during the S-phase. Variable fluorescence patterns, drastic changes in SNR, shape and position changes and abundance of touching cells require sophisticated algorithms for reliable automatic segmentation and cell cycle classification. We extend the recently proposed graph partitioning active contours (GPAC) for fluorescence-based nucleus segmentation using regional density functions and dramatically improve its efficiency, making it scalable for high content microscopy imaging. We utilize surface shape properties of GFP-PCNA intensity field to obtain descriptors of foci patterns and perform automated cell cycle phase classification, and give quantitative performance by comparing our results to manually labeled data.

  16. Epigenetic dynamics across the cell cycle

    DEFF Research Database (Denmark)

    Kheir, Tony Bou; Lund, Anders H.

    2010-01-01

    Progression of the mammalian cell cycle depends on correct timing and co-ordination of a series of events, which are managed by the cellular transcriptional machinery and epigenetic mechanisms governing genome accessibility. Epigenetic chromatin modifications are dynamic across the cell cycle...... a correct inheritance of epigenetic chromatin modifications to daughter cells. In this chapter, we summarize the current knowledge on the dynamics of epigenetic chromatin modifications during progression of the cell cycle....

  17. Apoptosis Induction by Polygonum minus is related to antioxidant capacity, alterations in expression of apoptotic-related genes, and S-phase cell cycle arrest in HepG2 cell line.

    Science.gov (United States)

    Mohd Ghazali, Mohd Alfazari; Al-Naqeb, Ghanya; Krishnan Selvarajan, Kesavanarayanan; Hazizul Hasan, Mizaton; Adam, Aishah

    2014-01-01

    Polygonum minus (Polygonaceae) is a medicinal herb distributed throughout eastern Asia. The present study investigated antiproliferative effect of P. minus and its possible mechanisms. Four extracts (petroleum ether, methanol, ethyl acetate, and water) were prepared by cold maceration. Extracts were subjected to phytochemical screening, antioxidant, and antiproliferative assays; the most bioactive was fractionated using vacuum liquid chromatography into seven fractions (F1-F7). Antioxidant activity was measured via total phenolic content (TPC), 2,2-diphenyl-1-picrylhydrazyl (DPPH), and ferric reducing antioxidant power (FRAP) assays. Antiproliferative activity was evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Most active fraction was tested for apoptosis induction and cell cycle arrest in HepG2 cells using flow cytometry and confocal microscopy. Apoptotic-related gene expression was studied by RT-PCR. Ethyl acetate extract was bioactive in initial assays. Its fraction, F7, exhibited highest antioxidant capacity (TPC; 113.16 ± 6.2 mg GAE/g extract, DPPH; EC50: 30.5 ± 3.2 μg/mL, FRAP; 1169 ± 20.3 μmol Fe (II)/mg extract) and selective antiproliferative effect (IC50: 25.75 ± 1.5 μg/mL). F7 induced apoptosis in concentration- and time-dependent manner and caused cell cycle arrest at S-phase. Upregulation of proapoptotic genes (Bax, p53, and caspase-3) and downregulation of antiapoptotic gene, Bcl-2, were observed. In conclusion, F7 was antiproliferative to HepG2 cells by inducing apoptosis, cell cycle arrest, and via antioxidative effects.

  18. UV-induced changes in cell cycle and gene expression within rabbit lens epithelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Sidjanin, D. [Northern Illinois Univ., De Kalb, IL (United States). Dept. of Biological Sciences; Grdina, D. [Argonne National Lab., IL (United States); Woloschak, G.E. [Northern Illinois Univ., De Kalb, IL (United States). Dept. of Biological Sciences

    1994-11-01

    Damage to lens epithelial cells is a probable initiation process in cataract formation induced by ultraviolet radiation. These experiments investigated the ability of 254 nm radiation on cell cycle progression and gene expression in rabbit lens epithelial cell line N/N1003A. No changes in expression of c-fos, c-jun, alpha- tubulin, or vimentin was observed following UV exposure. Using flow cytometry, an accumulation of cells in G1/S phase of the cell cycle 1 hr following exposure. The observed changes in gene expression, especially the decreased histone transcripts reported here may play a role in UV induced inhibition of cell cycle progression.

  19. NSA2, a novel nucleolus protein regulates cell proliferation and cell cycle

    International Nuclear Information System (INIS)

    Zhang, Heyu; Ma, Xi; Shi, Taiping; Song, Quansheng; Zhao, Hongshan; Ma, Dalong

    2010-01-01

    NSA2 (Nop seven-associated 2) was previously identified in a high throughput screen of novel human genes associated with cell proliferation, and the NSA2 protein is evolutionarily conserved across different species. In this study, we revealed that NSA2 is broadly expressed in human tissues and cultured cell lines, and located in the nucleolus of the cell. Both of the putative nuclear localization signals (NLSs) of NSA2, also overlapped with nucleolar localization signals (NoLSs), are capable of directing nucleolar accumulation. Moreover, over-expression of the NSA2 protein promoted cell growth in different cell lines and regulated the G1/S transition in the cell cycle. SiRNA silencing of the NSA2 transcript attenuated the cell growth and dramatically blocked the cell cycle in G1/S transition. Our results demonstrated that NSA2 is a nucleolar protein involved in cell proliferation and cell cycle regulation.

  20. Tuft (caveolated) cells in two human colon carcinoma cell lines.

    OpenAIRE

    Barkla, D. H.; Whitehead, R. H.; Foster, H.; Tutton, P. J.

    1988-01-01

    The presence of an unusual cell type in two human colon carcinoma cell lines is reported. The cells show the same morphology as "tuft" (caveolated) cells present in normal gastrointestinal epithelium. Tuft cells were seen in cell line LIM 1863 growing in vitro and in human colon carcinoma cell line LIM 2210 growing as subcutaneous solid tumour xenografts in nude mice. Characteristic morphologic features of tuft cells included a wide base, narrow apex and a tuft of long microvilli projecting f...

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

    Science.gov (United States)

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

    1984-11-01

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

  2. Cell cycle control by components of cell anchorage

    OpenAIRE

    Gad, Annica

    2005-01-01

    Extracellular factors, such as growth factors and cell anchorage to the extracellular matrix, control when and where cells may proliferate. This control is abolished when a normal cell transforms into a tumour cell. The control of cell proliferation by cell anchorage was elusive and less well studied than the control by growth factors. Therefore, we aimed to clarify at what points in the cell cycle and through which molecular mechanisms cell anchorage controls cell cycle pro...

  3. Pathway-specific differences between tumor cell lines and normal and tumor tissue cells

    Directory of Open Access Journals (Sweden)

    Tozeren Aydin

    2006-11-01

    Full Text Available Abstract Background Cell lines are used in experimental investigation of cancer but their capacity to represent tumor cells has yet to be quantified. The aim of the study was to identify significant alterations in pathway usage in cell lines in comparison with normal and tumor tissue. Methods This study utilized a pathway-specific enrichment analysis of publicly accessible microarray data and quantified the gene expression differences between cell lines, tumor, and normal tissue cells for six different tissue types. KEGG pathways that are significantly different between cell lines and tumors, cell lines and normal tissues and tumor and normal tissue were identified through enrichment tests on gene lists obtained using Significance Analysis of Microarrays (SAM. Results Cellular pathways that were significantly upregulated in cell lines compared to tumor cells and normal cells of the same tissue type included ATP synthesis, cell communication, cell cycle, oxidative phosphorylation, purine, pyrimidine and pyruvate metabolism, and proteasome. Results on metabolic pathways suggested an increase in the velocity nucleotide metabolism and RNA production. Pathways that were downregulated in cell lines compared to tumor and normal tissue included cell communication, cell adhesion molecules (CAMs, and ECM-receptor interaction. Only a fraction of the significantly altered genes in tumor-to-normal comparison had similar expressions in cancer cell lines and tumor cells. These genes were tissue-specific and were distributed sparsely among multiple pathways. Conclusion Significantly altered genes in tumors compared to normal tissue were largely tissue specific. Among these genes downregulation was a major trend. In contrast, cell lines contained large sets of significantly upregulated genes that were common to multiple tissue types. Pathway upregulation in cell lines was most pronounced over metabolic pathways including cell nucleotide metabolism and oxidative

  4. Effect of failures and repairs on multiple cell production lines

    Energy Technology Data Exchange (ETDEWEB)

    Legato, P.; Bobbio, A.; Roberti, L.

    1989-01-01

    This paper examines a production line composed of multiple stages, or cells, which are passed in sequential order to arrive to the final product. Two possible coordination disciplines are considered, namely: the classical tandem arrangement of sequential working centers with input buffer and the kanban scheme, considered the Japanese shop floor realization of the Just-In-Time (JIT) manifacturing approach. The production line is modelled and analysed by means of Stochastic Petri Nets (SPN). Finally an analysis is made of the possibility that the working cells can incur failure/repair cycles perturbing the production flow of the line and thus reduce performance indices.

  5. Cell cycle gene expression under clinorotation

    Science.gov (United States)

    Artemenko, Olga

    2016-07-01

    Cyclins and cyclin-dependent kinase (CDK) are main regulators of the cell cycle of eukaryotes. It's assumes a significant change of their level in cells under microgravity conditions and by other physical factors actions. The clinorotation use enables to determine the influence of gravity on simulated events in the cell during the cell cycle - exit from the state of quiet stage and promotion presynthetic phase (G1) and DNA synthesis phase (S) of the cell cycle. For the clinorotation effect study on cell proliferation activity is the necessary studies of molecular mechanisms of cell cycle regulation and development of plants under altered gravity condition. The activity of cyclin D, which is responsible for the events of the cell cycle in presynthetic phase can be controlled by the action of endogenous as well as exogenous factors, but clinorotation is one of the factors that influence on genes expression that regulate the cell cycle.These data can be used as a model for further research of cyclin - CDK complex for study of molecular mechanisms regulation of growth and proliferation. In this investigation we tried to summarize and analyze known literature and own data we obtained relatively the main regulators of the cell cycle in altered gravity condition.

  6. Lactobacillus Decelerates Cervical Epithelial Cell Cycle Progression

    Science.gov (United States)

    Vielfort, Katarina; Weyler, Linda; Söderholm, Niklas; Engelbrecht, Mattias; Löfmark, Sonja; Aro, Helena

    2013-01-01

    We investigated cell cycle progression in epithelial cervical ME-180 cells during colonization of three different Lactobacillus species utilizing live cell microscopy, bromodeoxyuridine incorporation assays, and flow cytometry. The colonization of these ME-180 cells by L. rhamnosus and L. reuteri, originating from human gastric epithelia and saliva, respectively, was shown to reduce cell cycle progression and to cause host cells to accumulate in the G1 phase of the cell cycle. The G1 phase accumulation in L. rhamnosus-colonized cells was accompanied by the up-regulation and nuclear accumulation of p21. By contrast, the vaginal isolate L. crispatus did not affect cell cycle progression. Furthermore, both the supernatants from the lactic acid-producing L. rhamnosus colonies and lactic acid added to cell culture media were able to reduce the proliferation of ME-180 cells. In this study, we reveal the diversity of the Lactobacillus species to affect host cell cycle progression and demonstrate that L. rhamnosus and L. reuteri exert anti-proliferative effects on human cervical carcinoma cells. PMID:23675492

  7. Lactobacillus decelerates cervical epithelial cell cycle progression.

    Directory of Open Access Journals (Sweden)

    Katarina Vielfort

    Full Text Available We investigated cell cycle progression in epithelial cervical ME-180 cells during colonization of three different Lactobacillus species utilizing live cell microscopy, bromodeoxyuridine incorporation assays, and flow cytometry. The colonization of these ME-180 cells by L. rhamnosus and L. reuteri, originating from human gastric epithelia and saliva, respectively, was shown to reduce cell cycle progression and to cause host cells to accumulate in the G1 phase of the cell cycle. The G1 phase accumulation in L. rhamnosus-colonized cells was accompanied by the up-regulation and nuclear accumulation of p21. By contrast, the vaginal isolate L. crispatus did not affect cell cycle progression. Furthermore, both the supernatants from the lactic acid-producing L. rhamnosus colonies and lactic acid added to cell culture media were able to reduce the proliferation of ME-180 cells. In this study, we reveal the diversity of the Lactobacillus species to affect host cell cycle progression and demonstrate that L. rhamnosus and L. reuteri exert anti-proliferative effects on human cervical carcinoma cells.

  8. Protein tyrosine nitration in the cell cycle

    International Nuclear Information System (INIS)

    Jia, Min; Mateoiu, Claudia; Souchelnytskyi, Serhiy

    2011-01-01

    Highlights: → Enrichment of 3-nitrotyrosine containing proteins from cells synchronized in different phases of the cell cycle. → Identification of 76 tyrosine nitrated proteins that change expression during the cell cycle. → Nineteen identified proteins were previously described as regulators of cell proliferation. -- Abstract: Nitration of tyrosine residues in proteins is associated with cell response to oxidative/nitrosative stress. Tyrosine nitration is relatively low abundant post-translational modification that may affect protein functions. Little is known about the extent of protein tyrosine nitration in cells during progression through the cell cycle. Here we report identification of proteins enriched for tyrosine nitration in cells synchronized in G0/G1, S or G2/M phases of the cell cycle. We identified 27 proteins in cells synchronized in G0/G1 phase, 37 proteins in S phase synchronized cells, and 12 proteins related to G2/M phase. Nineteen of the identified proteins were previously described as regulators of cell proliferation. Thus, our data indicate which tyrosine nitrated proteins may affect regulation of the cell cycle.

  9. Transcriptional Waves in the Yeast Cell Cycle

    OpenAIRE

    Oliva, Anna; Rosebrock, Adam; Ferrezuelo, Francisco; Pyne, Saumyadipta; Chen, Haiying; Skiena, Steve; Futcher, Bruce; Leatherwood, Janet

    2005-01-01

    Many genes are regulated as an innate part of the eukaryotic cell cycle, and a complex transcriptional network helps enable the cyclic behavior of dividing cells. This transcriptional network has been studied in Saccharomyces cerevisiae (budding yeast) and elsewhere. To provide more perspective on these regulatory mechanisms, we have used microarrays to measure gene expression through the cell cycle of Schizosaccharomyces pombe (fission yeast). The 750 genes with the most significant oscillat...

  10. Regulation of cell cycle progression by cell-cell and cell-matrix forces

    NARCIS (Netherlands)

    Uroz, Marina; Wistorf, Sabrina; Serra-Picamal, Xavier; Conte, Vito; Sales-Pardo, Marta; Roca-Cusachs, Pere; Guimerà, Roger; Trepat, Xavier

    2018-01-01

    It has long been proposed that the cell cycle is regulated by physical forces at the cell-cell and cell-extracellular matrix (ECM) interfaces 1-12 . However, the evolution of these forces during the cycle has never been measured in a tissue, and whether this evolution affects cell cycle progression

  11. Global Conservation of Protein Status between Cell Lines and Xenografts

    Directory of Open Access Journals (Sweden)

    Julian Biau

    2016-08-01

    Full Text Available Common preclinical models for testing anticancer treatment include cultured human tumor cell lines in monolayer, and xenografts derived from these cell lines in immunodeficient mice. Our goal was to determine how similar the xenografts are compared with their original cell line and to determine whether it is possible to predict the stability of a xenograft model beforehand. We studied a selection of 89 protein markers of interest in 14 human cell cultures and respective subcutaneous xenografts using the reverse-phase protein array technology. We specifically focused on proteins and posttranslational modifications involved in DNA repair, PI3K pathway, apoptosis, tyrosine kinase signaling, stress, cell cycle, MAPK/ERK signaling, SAPK/JNK signaling, NFκB signaling, and adhesion/cytoskeleton. Using hierarchical clustering, most cell culture-xenograft pairs cluster together, suggesting a global conservation of protein signature. Particularly, Akt, NFkB, EGFR, and Vimentin showed very stable protein expression and phosphorylation levels highlighting that 4 of 10 pathways were highly correlated whatever the model. Other proteins were heterogeneously conserved depending on the cell line. Finally, cell line models with low Akt pathway activation and low levels of Vimentin gave rise to more reliable xenograft models. These results may be useful for the extrapolation of cell culture experiments to in vivo models in novel targeted drug discovery.

  12. Identification of a novel EGF-sensitive cell cycle checkpoint

    International Nuclear Information System (INIS)

    Walker, Francesca; Zhang Huihua; Burgess, Antony W.

    2007-01-01

    The site of action of growth factors on mammalian cell cycle has been assigned to the boundary between the G1 and S phases. We show here that Epidermal Growth Factor (EGF) is also required for mitosis. BaF/3 cells expressing the EGFR (BaF/wtEGFR) synthesize DNA in response to EGF, but arrest in S-phase. We have generated a cell line (BaF/ERX) with defective downregulation of the EGFR and sustained activation of EGFR signalling pathways: these cells undergo mitosis in an EGF-dependent manner. The transit of BaF/ERX cells through G2/M strictly requires activation of EGFR and is abolished by AG1478. This phenotype is mimicked by co-expression of ErbB2 in BaF/wtEGFR cells, and abolished by inhibition of the EGFR kinase, suggesting that sustained signalling of the EGFR, through impaired downregulation of the EGFR or heterodimerization, is required for completion of the cycle. We have confirmed the role of EGFR signalling in the G2/M phase of the cell cycle using a human tumor cell line which overexpresses the EGFR and is dependent on EGFR signalling for growth. These findings unmask an EGF-sensitive checkpoint, helping to understand the link between sustained EGFR signalling, proliferation and the acquisition of a radioresistant phenotype in cancer cells

  13. Cell Cycle Deregulation in Ewing's Sarcoma Pathogenesis

    Science.gov (United States)

    Kowalewski, Ashley A.; Randall, R. Lor; Lessnick, Stephen L.

    2011-01-01

    Ewing's sarcoma is a highly aggressive pediatric tumor of bone that usually contains the characteristic chromosomal translocation t(11;22)(q24;q12). This translocation encodes the oncogenic fusion protein EWS/FLI, which acts as an aberrant transcription factor to deregulate target genes necessary for oncogenesis. One key feature of oncogenic transformation is dysregulation of cell cycle control. It is therefore likely that EWS/FLI and other cooperating mutations in Ewing's sarcoma modulate the cell cycle to facilitate tumorigenesis. This paper will summarize current published data associated with deregulation of the cell cycle in Ewing's sarcoma and highlight important questions that remain to be answered. PMID:21052502

  14. Cell Cycle Deregulation in Ewing's Sarcoma Pathogenesis

    Directory of Open Access Journals (Sweden)

    Ashley A. Kowalewski

    2011-01-01

    Full Text Available Ewing's sarcoma is a highly aggressive pediatric tumor of bone that usually contains the characteristic chromosomal translocation t(11;22(q24;q12. This translocation encodes the oncogenic fusion protein EWS/FLI, which acts as an aberrant transcription factor to deregulate target genes necessary for oncogenesis. One key feature of oncogenic transformation is dysregulation of cell cycle control. It is therefore likely that EWS/FLI and other cooperating mutations in Ewing's sarcoma modulate the cell cycle to facilitate tumorigenesis. This paper will summarize current published data associated with deregulation of the cell cycle in Ewing's sarcoma and highlight important questions that remain to be answered.

  15. Regulation of the cell cycle by irradiation

    International Nuclear Information System (INIS)

    Akashi, Makoto

    1995-01-01

    The molecular mechanism of cell proliferation is extremely complex; deregulation results in neoplastic transformation. In eukaryotes, proliferation of cells is finely regulated through the cell cycle. Studies have shown that the cell cycle is regulated by s series of enzymes known as cyclin-dependent kinases (CDKs). The activities of CDKs are controlled by their association with regulatory subunits, cyclins; the expression of cyclins and the activation of the different cyclin-CDK complexes are required for the cell to cycle. Thus, the cell cycle is regulated by activating and inhibiting phosphorylation of the CDK subunits and this program has internal check points at different stages of the cell cycle. When cells are exposed to external insults such as DNA damaging agents, negative regulation of the cell cycle occurs; arrest in either G1 or G2 stage is induced to prevent the cells from prematurely entering into the next stage before DNA is repaired. Recently, a potent inhibitor of CDKs, which inhibits the phosphorylation of retinoblastoma susceptibility (Rb) gene product by cyclin A-CDK2, cyclin E-CDK2, cyclin D1-CDK4, and cyclin D2-CDK4 complexes has been identified. This protein named WAF1, Sdi1, Cip1, or p21 (a protein of Mr 21,000) contains a p53-binding site in its promoter and studies have reported that the expression of WAF1 was directly regulated by p53; cells with loss of p53 activity due to mutational alteration were unable to induce WAF1. This chapter will be focused on the mechanisms of the cell cycle including inhibitors of CDKs, and the induction of WAF1 by irradiation through a pathway independent of p53 will be also described. (author)

  16. Modelling cell population growth with applications to cancer therapy in human tumour cell lines.

    Science.gov (United States)

    Basse, Britta; Baguley, Bruce C; Marshall, Elaine S; Wake, Graeme C; Wall, David J N

    2004-01-01

    In this paper we present an overview of the work undertaken to model a population of cells and the effects of cancer therapy. We began with a theoretical one compartment size structured cell population model and investigated its asymptotic steady size distributions (SSDs) (On a cell growth model for plankton, MMB JIMA 21 (2004) 49). However these size distributions are not similar to the DNA (size) distributions obtained experimentally via the flow cytometric analysis of human tumour cell lines (data obtained from the Auckland Cancer Society Research Centre, New Zealand). In our one compartment model, size was a generic term, but in order to obtain realistic steady size distributions we chose size to be DNA content and devised a multi-compartment mathematical model for the cell division cycle where each compartment corresponds to a distinct phase of the cell cycle (J. Math. Biol. 47 (2003) 295). We then incorporated another compartment describing the possible induction of apoptosis (cell death) from mitosis phase (Modelling cell death in human tumour cell lines exposed to anticancer drug paclitaxel, J. Math. Biol. 2004, in press). This enabled us to compare our model to flow cytometric data of a melanoma cell line where the anticancer drug, paclitaxel, had been added. The model gives a dynamic picture of the effects of paclitaxel on the cell cycle. We hope to use the model to describe the effects of other cancer therapies on a number of different cell lines. Copyright 2004 Elsevier Ltd.

  17. Establishment of cell lines with rat spermatogonial stem cell characteristics

    NARCIS (Netherlands)

    van Pelt, Ans M. M.; Roepers-Gajadien, Hermien L.; Gademan, Iris S.; Creemers, Laura B.; de Rooij, Dirk G.; van Dissel-Emiliani, Federica M. F.

    2002-01-01

    Spermatogonial cell lines were established by transfecting a mixed population of purified rat A(s) (stem cells), A(pr) and A(al) spermatogonia with SV40 large T antigen. Two cell lines were characterized and found to express Hsp90alpha and oct-4, specific markers for germ cells and A spermatogonia,

  18. NONO couples the circadian clock to the cell cycle.

    Science.gov (United States)

    Kowalska, Elzbieta; Ripperger, Juergen A; Hoegger, Dominik C; Bruegger, Pascal; Buch, Thorsten; Birchler, Thomas; Mueller, Anke; Albrecht, Urs; Contaldo, Claudio; Brown, Steven A

    2013-01-29

    Mammalian circadian clocks restrict cell proliferation to defined time windows, but the mechanism and consequences of this interrelationship are not fully understood. Previously we identified the multifunctional nuclear protein NONO as a partner of circadian PERIOD (PER) proteins. Here we show that it also conveys circadian gating to the cell cycle, a connection surprisingly important for wound healing in mice. Specifically, although fibroblasts from NONO-deficient mice showed approximately normal circadian cycles, they displayed elevated cell doubling and lower cellular senescence. At a molecular level, NONO bound to the p16-Ink4A cell cycle checkpoint gene and potentiated its circadian activation in a PER protein-dependent fashion. Loss of either NONO or PER abolished this activation and circadian expression of p16-Ink4A and eliminated circadian cell cycle gating. In vivo, lack of NONO resulted in defective wound repair. Because wound healing defects were also seen in multiple circadian clock-deficient mouse lines, our results therefore suggest that coupling of the cell cycle to the circadian clock via NONO may be useful to segregate in temporal fashion cell proliferation from tissue organization.

  19. Radiosensitization of colorectal carcinoma cell lines by histone deacetylase inhibition

    International Nuclear Information System (INIS)

    Flatmark, Kjersti; Nome, Ragnhild V; Folkvord, Sigurd; Bratland, Åse; Rasmussen, Heidi; Ellefsen, Mali Strand; Fodstad, Øystein; Ree, Anne Hansen

    2006-01-01

    The tumor response to preoperative radiotherapy of locally advanced rectal cancer varies greatly, warranting the use of experimental models to assay the efficacy of molecular targeting agents in rectal cancer radiosensitization. Histone deacetylase (HDAC) inhibitors, agents that cause hyperacetylation of histone proteins and thereby remodeling of chromatin structure, may override cell cycle checkpoint responses to DNA damage and amplify radiation-induced tumor cell death. Human colorectal carcinoma cell lines were exposed to ionizing radiation and HDAC inhibitors, and cell cycle profiles and regulatory factors, as well as clonogenicity, were analyzed. In addition to G 2 /M phase arrest following irradiation, the cell lines displayed cell cycle responses typical for either intact or defective p53 function (the presence or absence, respectively, of radiation-induced expression of the cell cycle inhibitor p21 and subsequent accumulation of G 1 phase cells). In contrast, histone acetylation was associated with complete depletion of the G 1 population of cells with functional p53 but accumulation of both G 1 and G 2 /M populations of cells with defective p53. The cellular phenotypes upon HDAC inhibition were consistent with the observed repression of Polo-like kinase-1, a regulatory G 2 /M phase kinase. Following pre-treatment with HDAC inhibitors currently undergoing clinical investigation, the inhibitory effect of ionizing radiation on clonogenicity was significantly amplified. In these experimental models, HDAC inhibition sensitized the tumor cells to ionizing radiation, which is in accordance with the concept of increased probability of tumor cell death when chromatin structure is modified

  20. The antiproliferative effect of coumarins on several cancer cell lines.

    Science.gov (United States)

    Kawaii, S; Tomono, Y; Ogawa, K; Sugiura, M; Yano, M; Yoshizawa, Y

    2001-01-01

    Twenty-one coumarins were examined for their antiproliferative activity towards several cancer cell lines, namely lung carcinoma (A549), melanin pigment producing mouse melanoma (B16 melanoma 4A5), human T-cell leukemia (CCRF-HSB-2), and human gastric cancer, lymph node metastasized (TGBC11TKB). The structure-activity relationship established from the results revealed that the 6,7-dihydroxy moiety had an important role for their antiproliferative activity. Analysis of cell cycle distribution indicated that esculetin-treated cells accumulated in the G1 (at 400 microM) or in S phase (at 100 microM).

  1. Cell cycle arrest induced by radiation

    International Nuclear Information System (INIS)

    Okaichi, Yasuo; Matsumoto, Hideki; Ohnishi, Takeo

    1994-01-01

    It is known that various chemical reactions, such as cell cycle arrest, DNA repair and cell killing, can occur within the cells when exposed to ionizing radiation and ultraviolet radiation. Thus protein dynamics involved in such chemical reactions has received considerable attention. In this article, cell cycle regulation is first discussed in terms of the G2/M-phase and the G1/S-phase. Then, radiation-induced cell cycle arrest is reviewed. Cell cycle regulation mechanism involved in the G2 arrest, which is well known to occur when exposed to radiation, has recently been investigated using yeasts. In addition, recent study has yielded a noticeable finding that the G1 arrest can occur with intracellular accumulation of p53 product following ionization radiation. p53 is also shown to play an extremely important role in both DNA repair and cell killing due to DNA damage. Studies on the role of genes in protein groups induced by radiation will hold promise for the elucidation of cell cycle mechanism. (N.K.) 57 refs

  2. 2-Aminopurine overrides multiple cell cycle checkpoints in BHK cells.

    OpenAIRE

    Andreassen, P R; Margolis, R L

    1992-01-01

    BHK cells blocked at any of several points in the cell cycle override their drug-induced arrest and proceed in the cycle when exposed concurrently to the protein kinase inhibitor 2-aminopurine (2-AP). For cells arrested at various points in interphase, 2-AP-induced cell cycle progression is made evident by arrival of the drug-treated cell population in mitosis. Cells that have escaped from mimosine G1 arrest, from hydroxyurea or aphidicolin S-phase arrest, or from VM-26-induced G2 arrest subs...

  3. A hybrid mammalian cell cycle model

    Directory of Open Access Journals (Sweden)

    Vincent Noël

    2013-08-01

    Full Text Available Hybrid modeling provides an effective solution to cope with multiple time scales dynamics in systems biology. Among the applications of this method, one of the most important is the cell cycle regulation. The machinery of the cell cycle, leading to cell division and proliferation, combines slow growth, spatio-temporal re-organisation of the cell, and rapid changes of regulatory proteins concentrations induced by post-translational modifications. The advancement through the cell cycle comprises a well defined sequence of stages, separated by checkpoint transitions. The combination of continuous and discrete changes justifies hybrid modelling approaches to cell cycle dynamics. We present a piecewise-smooth version of a mammalian cell cycle model, obtained by hybridization from a smooth biochemical model. The approximate hybridization scheme, leading to simplified reaction rates and binary event location functions, is based on learning from a training set of trajectories of the smooth model. We discuss several learning strategies for the parameters of the hybrid model.

  4. Cell Cycle Regulation of Stem Cells by MicroRNAs.

    Science.gov (United States)

    Mens, Michelle M J; Ghanbari, Mohsen

    2018-06-01

    MicroRNAs (miRNAs) are a class of small non-coding RNA molecules involved in the regulation of gene expression. They are involved in the fine-tuning of fundamental biological processes such as proliferation, differentiation, survival and apoptosis in many cell types. Emerging evidence suggests that miRNAs regulate critical pathways involved in stem cell function. Several miRNAs have been suggested to target transcripts that directly or indirectly coordinate the cell cycle progression of stem cells. Moreover, previous studies have shown that altered expression levels of miRNAs can contribute to pathological conditions, such as cancer, due to the loss of cell cycle regulation. However, the precise mechanism underlying miRNA-mediated regulation of cell cycle in stem cells is still incompletely understood. In this review, we discuss current knowledge of miRNAs regulatory role in cell cycle progression of stem cells. We describe how specific miRNAs may control cell cycle associated molecules and checkpoints in embryonic, somatic and cancer stem cells. We further outline how these miRNAs could be regulated to influence cell cycle progression in stem cells as a potential clinical application.

  5. Fuel cell hybrid taxi life cycle analysis

    Energy Technology Data Exchange (ETDEWEB)

    Baptista, Patricia, E-mail: patricia.baptista@ist.utl.pt [IDMEC-Instituto Superior Tecnico, Universidade Tecnica de Lisboa, Av. Rovisco Pais, 1, 1049-001 Lisboa (Portugal); Ribau, Joao; Bravo, Joao; Silva, Carla [IDMEC-Instituto Superior Tecnico, Universidade Tecnica de Lisboa, Av. Rovisco Pais, 1, 1049-001 Lisboa (Portugal); Adcock, Paul; Kells, Ashley [Intelligent Energy, Charnwood Building, HolywellPark, Ashby Road, Loughborough, LE11 3GR (United Kingdom)

    2011-09-15

    A small fleet of classic London Taxis (Black cabs) equipped with hydrogen fuel cell power systems is being prepared for demonstration during the 2012 London Olympics. This paper presents a Life Cycle Analysis for these vehicles in terms of energy consumption and CO{sub 2} emissions, focusing on the impacts of alternative vehicle technologies for the Taxi, combining the fuel life cycle (Tank-to-Wheel and Well-to-Tank) and vehicle materials Cradle-to-Grave. An internal combustion engine diesel taxi was used as the reference vehicle for the currently available technology. This is compared to battery and fuel cell vehicle configurations. Accordingly, the following energy pathways are compared: diesel, electricity and hydrogen (derived from natural gas steam reforming). Full Life Cycle Analysis, using the PCO-CENEX drive cycle, (derived from actual London Taxi drive cycles) shows that the fuel cell powered vehicle configurations have lower energy consumption (4.34 MJ/km) and CO{sub 2} emissions (235 g/km) than both the ICE Diesel (9.54 MJ/km and 738 g/km) and the battery electric vehicle (5.81 MJ/km and 269 g/km). - Highlights: > A Life Cycle Analysis of alternative vehicle technologies for the London Taxi was performed. > The hydrogen powered vehicles have the lowest energy consumption and CO{sub 2} emissions results. > A hydrogen powered solution can be a sustainable alternative in a full life cycle framework.

  6. Fuel cell hybrid taxi life cycle analysis

    International Nuclear Information System (INIS)

    Baptista, Patricia; Ribau, Joao; Bravo, Joao; Silva, Carla; Adcock, Paul; Kells, Ashley

    2011-01-01

    A small fleet of classic London Taxis (Black cabs) equipped with hydrogen fuel cell power systems is being prepared for demonstration during the 2012 London Olympics. This paper presents a Life Cycle Analysis for these vehicles in terms of energy consumption and CO 2 emissions, focusing on the impacts of alternative vehicle technologies for the Taxi, combining the fuel life cycle (Tank-to-Wheel and Well-to-Tank) and vehicle materials Cradle-to-Grave. An internal combustion engine diesel taxi was used as the reference vehicle for the currently available technology. This is compared to battery and fuel cell vehicle configurations. Accordingly, the following energy pathways are compared: diesel, electricity and hydrogen (derived from natural gas steam reforming). Full Life Cycle Analysis, using the PCO-CENEX drive cycle, (derived from actual London Taxi drive cycles) shows that the fuel cell powered vehicle configurations have lower energy consumption (4.34 MJ/km) and CO 2 emissions (235 g/km) than both the ICE Diesel (9.54 MJ/km and 738 g/km) and the battery electric vehicle (5.81 MJ/km and 269 g/km). - Highlights: → A Life Cycle Analysis of alternative vehicle technologies for the London Taxi was performed. → The hydrogen powered vehicles have the lowest energy consumption and CO 2 emissions results. → A hydrogen powered solution can be a sustainable alternative in a full life cycle framework.

  7. Toona Sinensis Extracts Induced Cell Cycle Arrest and Apoptosis in the Human Lung Large Cell Carcinoma

    Directory of Open Access Journals (Sweden)

    Cheng-Yuan Wang

    2010-02-01

    Full Text Available Toona sinensis extracts have been shown to exhibit anti-cancer effects in human ovarian cancer cell lines, human promyelocytic leukemia cells and human lung adenocarcinoma. Its safety has also been confirmed in animal studies. However, its anti-cancer properties in human lung large cell carcinoma have not been studied. Here, we used a powder obtained by freeze-drying the super-natant of centrifuged crude extract from Toona sinensis leaves (TSL-1 to treat the human lung carcinoma cell line H661. Cell viability was evaluated by the 3-(4-,5-dimethylthiazol-2-yl-2,5-diphenyl tetrazolium bromide assay. Flow cytometry analysis revealed that TSL-1 blocked H661 cell cycle progression. Western blot analysis showed decreased expression of cell cycle proteins that promote cell cycle progression, including cyclin-dependent kinase 4 and cyclin D1, and increased the expression of proteins that inhibit cell cycle progression, including p27. Furthermore, flow cytometry analysis showed that TSL-1 induced H661 cell apoptosis. Western blot analysis showed that TSL-1 reduced the expression of the anti-apoptotic protein B-cell lymphoma 2, and degraded the DNA repair protein, poly(ADP-ribose polymerase. TSL-1 shows potential as a novel therapeutic agent or for use as an adjuvant for treating human lung large cell carcinoma.

  8. A nuclear glutathione cycle within the cell cycle.

    Science.gov (United States)

    Diaz Vivancos, Pedro; Wolff, Tonja; Markovic, Jelena; Pallardó, Federico V; Foyer, Christine H

    2010-10-15

    The complex antioxidant network of plant and animal cells has the thiol tripeptide GSH at its centre to buffer ROS (reactive oxygen species) and facilitate cellular redox signalling which controls growth, development and defence. GSH is found in nearly every compartment of the cell, including the nucleus. Transport between the different intracellular compartments is pivotal to the regulation of cell proliferation. GSH co-localizes with nuclear DNA at the early stages of proliferation in plant and animal cells. Moreover, GSH recruitment and sequestration in the nucleus during the G1- and S-phases of the cell cycle has a profound impact on cellular redox homoeostasis and on gene expression. For example, the abundance of transcripts encoding stress and defence proteins is decreased when GSH is sequestered in the nucleus. The functions of GSHn (nuclear GSH) are considered in the present review in the context of whole-cell redox homoeostasis and signalling, as well as potential mechanisms for GSH transport into the nucleus. We also discuss the possible role of GSHn as a regulator of nuclear proteins such as histones and PARP [poly(ADP-ribose) polymerase] that control genetic and epigenetic events. In this way, a high level of GSH in the nucleus may not only have an immediate effect on gene expression patterns, but also contribute to how cells retain a memory of the cellular redox environment that is transferred through generations.

  9. Labeling of lectin receptors during the cell cycle.

    Science.gov (United States)

    Garrido, J

    1976-12-01

    Labeling of lectin receptors during the cell cycle. (Localizabión de receptores para lectinas durante el ciclo celular). Arch. Biol. Med. Exper. 10: 100-104, 1976. The topographic distribution of specific cell surface receptors for concanavalin A and wheat germ agglutinin was studied by ultrastructural labeling in the course of the cell cycle. C12TSV5 cells were synchronized by double thymidine block or mechanical selection (shakeoff). They were labeled by means of lectin-peroxidase techniques while in G1 S, G2 and M phases of the cycle. The results obtained were similar for both lectins employed. Interphase cells (G1 S, G2) present a stlihtly discontinous labeling pattern that is similar to the one observed on unsynchronized cells of the same line. Cells in mitosis, on the contrary, present a highly discontinous distribution of reaction product. This pattern disappears after the cells enters G1 and is not present on mitotic cells fixed in aldehyde prior to labeling.

  10. Do lipids shape the eukaryotic cell cycle?

    Science.gov (United States)

    Furse, Samuel; Shearman, Gemma C

    2018-01-01

    Successful passage through the cell cycle presents a number of structural challenges to the cell. Inceptive studies carried out in the last five years have produced clear evidence of modulations in the lipid profile (sometimes referred to as the lipidome) of eukaryotes as a function of the cell cycle. This mounting body of evidence indicates that lipids play key roles in the structural transformations seen across the cycle. The accumulation of this evidence coincides with a revolution in our understanding of how lipid composition regulates a plethora of biological processes ranging from protein activity through to cellular signalling and membrane compartmentalisation. In this review, we discuss evidence from biological, chemical and physical studies of the lipid fraction across the cell cycle that demonstrate that lipids are well-developed cellular components at the heart of the biological machinery responsible for managing progress through the cell cycle. Furthermore, we discuss the mechanisms by which this careful control is exercised. Crown Copyright © 2017. Published by Elsevier B.V. All rights reserved.

  11. [Effects of ezrin silencing on pancreatic cancer cell line Panc-1].

    Science.gov (United States)

    Meng, Yun-xiao; Yu, Shuang-ni; Lu, Zhao-hui; Chen, Jie

    2012-12-01

    To explore the effects of ezrin silencing on pancreatic cancer cell line Panc-1. Pancreatic cancer cell line Panc-1 was transfected with ezrin silencing plasmid. The proliferation and the cell cycle status were determined by CCK-8 assay and flow cytometry analysis, respectively. Cellular membrane protrusions/microvilli formation were visualized by scanning election microscopy. Colony formation assay was used to determine the cell anchor-independent growth ability in vitro. Trans-filter migration and invasion assays were performed with 8 µm pore inserts in a 24-well BioCoat chamber with/without Matrigel. Ezrin silencing decreased cellular protrusions/microvilli formation, anchorage-independent growth, cell migration and invasion, but had no effects on cell proliferation in vitro and cell cycle, in pancreatic cancer cell line Panc-1. Ezrin expression affects the cellular protrusions/microvilli formation, anchorage-independent growth, cell migration and invasion in pancreatic cancer cell line Panc-1.

  12. Cell lines authentication and mycoplasma detection as minimun quality control of cell lines in biobanking.

    Science.gov (United States)

    Corral-Vázquez, C; Aguilar-Quesada, R; Catalina, P; Lucena-Aguilar, G; Ligero, G; Miranda, B; Carrillo-Ávila, J A

    2017-06-01

    Establishment of continuous cell lines from human normal and tumor tissues is an extended and useful methodology for molecular characterization of cancer pathophysiology and drug development in research laboratories. The exchange of these cell lines between different labs is a common practice that can compromise assays reliability due to contamination with microorganism such as mycoplasma or cells from different flasks that compromise experiment reproducibility and reliability. Great proportions of cell lines are contaminated with mycoplasma and/or are replaced by cells derived for a different origin during processing or distribution process. The scientific community has underestimated this problem and thousand of research experiment has been done with cell lines that are incorrectly identified and wrong scientific conclusions have been published. Regular contamination and authentication tests are necessary in order to avoid negative consequences of widespread misidentified and contaminated cell lines. Cell banks generate, store and distribute cell lines for research, being mandatory a consistent and continuous quality program. Methods implementation for guaranteeing both, the absence of mycoplasma and authentication in the supplied cell lines, has been performed in the Andalusian Health System Biobank. Specifically, precise results were obtained using real time PCR detection for mycoplasma and 10 STRs identification by capillary electrophoresis for cell line authentication. Advantages and disadvantages of these protocols are discussed.

  13. Fraction against Human Cancer Cell Lines

    African Journals Online (AJOL)

    fraction of A. sieberi against seven cancer cell lines (Colo20, HCT116, DLD, MCF7, Jurkat, HepG2 and ... The morphology of the HepG2 cell nucleus was investigated by Hoechst 33342, ..... Gong F, Liang Y, Xie P, Chau F. Information theory.

  14. Cell reprogramming modelled as transitions in a hierarchy of cell cycles

    International Nuclear Information System (INIS)

    Hannam, Ryan; Annibale, Alessia; Kühn, Reimer

    2017-01-01

    We construct a model of cell reprogramming (the conversion of fully differentiated cells to a state of pluripotency, known as induced pluripotent stem cells, or iPSCs) which builds on key elements of cell biology viz. cell cycles and cell lineages. Although reprogramming has been demonstrated experimentally, much of the underlying processes governing cell fate decisions remain unknown. This work aims to bridge this gap by modelling cell types as a set of hierarchically related dynamical attractors representing cell cycles. Stages of the cell cycle are characterised by the configuration of gene expression levels, and reprogramming corresponds to triggering transitions between such configurations. Two mechanisms were found for reprogramming in a two level hierarchy: cycle specific perturbations and a noise induced switching. The former corresponds to a directed perturbation that induces a transition into a cycle-state of a different cell type in the potency hierarchy (mainly a stem cell) whilst the latter is a priori undirected and could be induced, e.g. by a (stochastic) change in the cellular environment. These reprogramming protocols were found to be effective in large regimes of the parameter space and make specific predictions concerning reprogramming dynamics which are broadly in line with experimental findings. (paper)

  15. Cell cycle kinetics and radiation therapy

    International Nuclear Information System (INIS)

    Mendelsohn, M.L.

    1975-01-01

    Radiation therapy as currently practiced involves the subtle largely empirical art of balancing the recurrence of cancer due to undertreatment against severe damage to local tissues due to overtreatment. Therapeutic results too often fall short of desired success rates; yet, the therapist is continually tantalized to the likelihood that a slight shift of therapeutic ratio favoring normal tissue over cancer would have a profoundly beneficial effect. The application of cell cycle kinetics to radiation therapy is one hope for improving the therapeutic ratio; but, as I will try to show, kinetic approaches are complex, poorly understood, and presently too elusive to elicit confidence or to be used clinically. Their promise lies in their diversity and in the magnitude of our ignorance about how they work and how they should be used. Potentially useful kinetic approaches to therapy can be grouped into three classes. The first class takes advantage of intracyclic differential sensitivity, an effect involving the metabolism and biology of the cell cycle; its strategies are based on synchronization of cells over intervals of hours to days. The second class involves the distinction between cycling and noncycling cells; its strategies are based on the resistance of noncycling cells to cycle-linked radiation sensitizers and chemotherapeutic agents. The third class uses cell repopulation between fractions; its strategies are based on the relative growth rates of tumor and relevant normal tissue before and after perturbation

  16. Cell Cycle Inhibition To Treat Sleeping Sickness

    Directory of Open Access Journals (Sweden)

    Conrad L. Epting

    2017-09-01

    Full Text Available African trypanosomiasis is caused by infection with the protozoan parasite Trypanosoma brucei. During infection, this pathogen divides rapidly to high density in the bloodstream of its mammalian host in a manner similar to that of leukemia. Like all eukaryotes, T. brucei has a cell cycle involving the de novo synthesis of DNA regulated by ribonucleotide reductase (RNR, which catalyzes the conversion of ribonucleotides into their deoxy form. As an essential enzyme for the cell cycle, RNR is a common target for cancer chemotherapy. We hypothesized that inhibition of RNR by genetic or pharmacological means would impair parasite growth in vitro and prolong the survival of infected animals. Our results demonstrate that RNR inhibition is highly effective in suppressing parasite growth both in vitro and in vivo. These results support drug discovery efforts targeting the cell cycle, not only for African trypanosomiasis but possibly also for other infections by eukaryotic pathogens.

  17. Cell-cycle phase specificity of chloroethylnitrosoureas

    International Nuclear Information System (INIS)

    Linfoot, P.A.

    1986-01-01

    Although the cancer chemotherapeutic agent 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) is considered a non-cell cycle phase specific drug, it has been shown to produce differential cell killing in G 1 , S, and G 2 /M phase cells, with S phase cells appearing relatively resistant. Studies of cell cycle phase specific cell killing produced by nitrosoureas with different chemical reactivities, clearly indicated that the ability of compounds to cross-link DNA was important in determining their phase specificity. Cells that lacked guanine O 6 -alkytransferase activity showed similar patterns of BCNU phase specificity regardless of their intrinsic sensitivity to BCNU. DNA inter-strand cross-linking, as measured by alkaline elution, was similar in cells exposed to BCNU in G 1 or S phase. 3 H [1-chloroethyl-1nitrosourea] binding to DNA was the same in G 1 , S and G 2 /M phase cells indicating that phase-specific differences in drug uptake and intracellular drug dose were not responsible for phase specific cell kill. These studies suggest that cross-link lesions, other than DNA inter-strand cross-links, and/or effects on DNA repair, other than guanine O 6 -alkyltransferase, are additional important determinants of BCNU phase specific cell killing

  18. Enhancement of Radiation Response in Osteosarcoma and Rhabomyosarcoma Cell Lines by Histone Deacetylase Inhibition

    International Nuclear Information System (INIS)

    Blattmann, Claudia; Oertel, Susanne; Ehemann, Volker

    2010-01-01

    Purpose: Histone deacetylase inhibitors (HDACIs) can enhance the sensitivity of cells to photon radiation treatment (XRT) by altering numerous molecular pathways. We investigated the effect of pan-HDACIs such as suberoylanilide hydroxamic acid (SAHA) on radiation response in two osteosarcoma (OS) and two rhabdomyosarcoma (RMS) cell lines. Methods and Materials: Clonogenic survival, cell cycle analysis, and apoptosis were examined in OS (KHOS-24OS, SAOS2) and RMS (A-204, RD) cell lines treated with HDACI and HDACI plus XRT, respectively. Protein expression was investigated via immunoblot analysis, and cell cycle analysis and measurement of apoptosis were performed using flow cytometry. Results: SAHA induced an inhibition of cell proliferation and clonogenic survival in OS and RMS cell lines and led to a significant radiosensitization of all tumor cell lines. Other HDACI such as M344 and valproate showed similar effects as investigated in one OS cell line. Furthermore, SAHA significantly increased radiation-induced apoptosis in the OS cell lines, whereas in the RMS cell lines radiation-induced apoptosis was insignificant with and without SAHA. In all investigated sarcoma cell lines, SAHA attenuated radiation-induced DNA repair protein expression (Rad51, Ku80). Conclusion: Our results show that HDACIs enhance radiation action in OS and RMS cell lines. Inhibition of DNA repair, as well as increased apoptosis induction after exposure to HDACIs, can be mechanisms of radiosensitization by HDACIs.

  19. Dipeptidyl peptidase IV in two human glioma cell lines

    Directory of Open Access Journals (Sweden)

    A Sedo

    2009-12-01

    Full Text Available There is growing evidence that dipeptidyl peptidase IV [DPP-IV, EC 3.4.14.5] takes part in the metabolism of biologically active peptides participating in the regulation of growth and transformation of glial cells. However, the knowledge on the DPP-IV expression in human glial and glioma cells is still very limited. In this study, using histochemical and biochemical techniques, the DPP-IV activity was demonstrated in two commercially available human glioma cell lines of different transformation degree, as represented by U373 astrocytoma (Grade III and U87 glioblastoma multiforme (Grade IV lines. Higher total activity of the enzyme, as well as its preferential localisation in the plasma membrane, was observed in U87 cells. Compared to U373 population, U87 cells were morphologically more pleiomorphic, they were cycling at lower rate and expressing less Glial Fibrillary Acidic Protein. The data revealed positive correlation between the degree of transformation of cells and activity of DPP-IV. Great difference in expression of this enzyme, together with the phenotypic differences of cells, makes these lines a suitable standard model for further 57 studies of function of this enzyme in human glioma cells.

  20. Control points within the cell cycle

    International Nuclear Information System (INIS)

    Van't Hof, J.

    1984-01-01

    Evidence of the temporal order of chromosomal DNA replication argues favorably for the view that the cell cycle is controlled by genes acting in sequence whose time of expression is determined by mitosis and the amount of nuclear DNA (2C vs 4C) in the cell. Gl and G2 appear to be carbohydrate dependent in that cells starved of either carbohydrate of phosphate fail to make these transitions. Cells deprived of nitrate, however, fail only at Gl to S transition indicating that the controls that operate in G1 differ from those that operate in G2. 46 references, 5 figures

  1. Cell fusion induced by ionizing radiation in various cell lines

    International Nuclear Information System (INIS)

    Khair, M.B.

    1994-07-01

    Cell fusion induced by ionizing radiation has been studied in rat's hepatocytes in vivo and in different cell lines in vitro. These cell lines were: Hela cells, V-79 fibroblasts, human and rat lymphocytes. For irradiation, 0.85 MeV fission neutrons and 14 MeV fast neutrons were used. Cell analyses were performed by fluorescent dyes using immunofluorescent microscope and flow cytometre. Our results in vivo showed that, regardless the dose-rate, a dose of 1 Gy approximately was enough to induce a significant level of cell fusion depending on neutron energy and the age of rats. The level of cell fusion was also significant in Hela cells at a dose of 0.5 Gy. Similar effect, but to a lesser extent, was observed in V-79 cells. Whereas, in lymphocytes insignificant cell fusion was noticed. The varying levels of cell-fusion in different cell lines could be attributed to the type of cells and mutual contact between cells. Furthermore irradiation did not show any influence on cell division ability in both hepatocytes and Hela cells and that fused cells were also able to divide forming a new generation of cells. (author). 36 refs., 8 figs., 10 tabs

  2. Cell Line Data Base: structure and recent improvements towards molecular authentication of human cell lines.

    Science.gov (United States)

    Romano, Paolo; Manniello, Assunta; Aresu, Ottavia; Armento, Massimiliano; Cesaro, Michela; Parodi, Barbara

    2009-01-01

    The Cell Line Data Base (CLDB) is a well-known reference information source on human and animal cell lines including information on more than 6000 cell lines. Main biological features are coded according to controlled vocabularies derived from international lists and taxonomies. HyperCLDB (http://bioinformatics.istge.it/hypercldb/) is a hypertext version of CLDB that improves data accessibility by also allowing information retrieval through web spiders. Access to HyperCLDB is provided through indexes of biological characteristics and navigation in the hypertext is granted by many internal links. HyperCLDB also includes links to external resources. Recently, an interest was raised for a reference nomenclature for cell lines and CLDB was seen as an authoritative system. Furthermore, to overcome the cell line misidentification problem, molecular authentication methods, such as fingerprinting, single-locus short tandem repeat (STR) profile and single nucleotide polymorphisms validation, were proposed. Since this data is distributed, a reference portal on authentication of human cell lines is needed. We present here the architecture and contents of CLDB, its recent enhancements and perspectives. We also present a new related database, the Cell Line Integrated Molecular Authentication (CLIMA) database (http://bioinformatics.istge.it/clima/), that allows to link authentication data to actual cell lines.

  3. Cell cycle and apoptosis genes in atherosclerosis

    NARCIS (Netherlands)

    Boesten, Lianne Simone Mirjam

    2006-01-01

    The work described in this thesis was aimed at identifying the role of cell cycle and apoptosis genes in atherosclerosis. Atherosclerosis is the primary cause of cardiovascular disease, a disorder occurring in the large and medium-sized arteries of the body. Although in the beginning 90s promising

  4. Dynamic ubiquitin signaling in cell cycle regulation.

    Science.gov (United States)

    Gilberto, Samuel; Peter, Matthias

    2017-08-07

    The cell division cycle is driven by a collection of enzymes that coordinate DNA duplication and separation, ensuring that genomic information is faithfully and perpetually maintained. The activity of the effector proteins that perform and coordinate these biological processes oscillates by regulated expression and/or posttranslational modifications. Ubiquitylation is a cardinal cellular modification and is long known for driving cell cycle transitions. In this review, we emphasize emerging concepts of how ubiquitylation brings the necessary dynamicity and plasticity that underlie the processes of DNA replication and mitosis. New studies, often focusing on the regulation of chromosomal proteins like DNA polymerases or kinetochore kinases, are demonstrating that ubiquitylation is a versatile modification that can be used to fine-tune these cell cycle events, frequently through processes that do not involve proteasomal degradation. Understanding how the increasing variety of identified ubiquitin signals are transduced will allow us to develop a deeper mechanistic perception of how the multiple factors come together to faithfully propagate genomic information. Here, we discuss these and additional conceptual challenges that are currently under study toward understanding how ubiquitin governs cell cycle regulation. © 2017 Gilberto and Peter.

  5. Susceptibility of Hep3B cells in different phases of cell cycle to tBid.

    Science.gov (United States)

    Ma, Shi-Hong; Chen, George G; Ye, Caiguo; Leung, Billy C S; Ho, Rocky L K; Lai, Paul B S

    2011-01-01

    tBid is a pro-apoptotic molecule. Apoptosis inducers usually act in a cell cycle-specific fashion. The aim of this study was to elucidate whether effect of tBid on hepatocellular carcinoma (HCC) Hep3B cells was cell cycle phase specific. We synchronized Hep3B cells at G0/G1, S or G2/M phases by chemicals or flow sorting and tested the susceptibility of the cells to recombinant tBid. Cell viability was measured by MTT assay and apoptosis by TUNEL. The results revealed that tBid primarily targeted the cells at G0/G1 phase of cell cycle, and it also increased the cells at the G2/M phase. 5-Fluorouracil (5-FU), on the other hand, arrested Hep3B cells at the G0/G1 phase, but significantly reduced cells at G2/M phase. The levels of cell cycle-related proteins and caspases were altered in line with the change in the cell cycle. The combination of tBid with 5-FU caused more cells to be apoptotic than either agent alone. Therefore, the complementary effect of tBid and 5-FU on different phases of the cell cycle may explain their synergistric effect on Hep3B cells. The elucidation of the phase-specific effect of tBid points to a possible therapeutic option that combines different phase specific agents to overcome resistance of HCC. Copyright © 2010 Elsevier B.V. All rights reserved.

  6. Capsaicin induces cell cycle arrest and apoptosis in human KB cancer cells.

    Science.gov (United States)

    Lin, Chia-Han; Lu, Wei-Cheng; Wang, Che-Wei; Chan, Ya-Chi; Chen, Mu-Kuan

    2013-02-25

    Capsaicin, a pungent phytochemical in a variety of red peppers of the genus Capsicum, has shown an anti-proliferative effect on various human cancer cell lines. In contrast, capsaicin has also been considered to promote the growth of cancer cells. Thus, the effects of capsaicin on various cell types need to be explored. The anti-proliferative effects of capsaicin on human KB cancer cells are still unknown. Therefore, we examined the viability, cell cycle progression, and factors associated with apoptosis in KB cells treated with capsaicin. The cell proliferation/viability and cytotoxicity of KB cells exposed to capsaicin were determined by a sulforhodamine B colorimetric assay and trypan blue exclusion. Apoptosis was detected by Hoechst staining and confirmed by western blot analysis of poly-(ADP-ribose) polymerase cleavage. Cell cycle distribution and changes of the mitochondrial membrane potential were analyzed by flow cytometry. Furthermore, the expression of caspase 3, 8 and 9 was evaluated by immunoblotting. We found that treatment of KB cells with capsaicin significantly reduced cell proliferation/viability and induced cell death in a dose-dependent manner compared with that in the untreated control. Cell cycle analysis indicated that exposure of KB cells to capsaicin resulted in cell cycle arrest at G2/M phase. Capsaicin-induced growth inhibition of KB cells appeared to be associated with induction of apoptosis. Moreover, capsaicin induced disruption of the mitochondrial membrane potential as well as activation of caspase 9, 3 and poly-(ADP-ribose) polymerase in KB cells. Our data demonstrate that capsaicin modulates cell cycle progression and induces apoptosis in human KB cancer cells through mitochondrial membrane permeabilization and caspase activation. These observations suggest an anti-cancer activity of capsaicin.

  7. Tuft (caveolated) cells in two human colon carcinoma cell lines.

    Science.gov (United States)

    Barkla, D H; Whitehead, R H; Foster, H; Tutton, P J

    1988-09-01

    The presence of an unusual cell type in two human colon carcinoma cell lines is reported. The cells show the same morphology as "tuft" (caveolated) cells present in normal gastrointestinal epithelium. Tuft cells were seen in cell line LIM 1863 growing in vitro and in human colon carcinoma cell line LIM 2210 growing as subcutaneous solid tumour xenografts in nude mice. Characteristic morphologic features of tuft cells included a wide base, narrow apex and a tuft of long microvilli projecting from the apical surface. The microvilli are attached by a core of long microfilaments passing deep into the apical cytoplasm. Between the microvilli are parallel arrays of vesicles (caveoli) containing flocculent material. Two different but not mutually exclusive explanations for the presence of tuft cells are proposed. The first explanation is that tuft cells came from the resected tumour and have survived by mitotic division during subsequent passages. The second explanation suggests that tuft cells are the progeny of undifferentiated tumour cells. Descriptions of tuft cells in colon carcinomas are uncommon and possible reasons for this are presented. The morphology of tuft cells is consistent with that of a highly differentiated cell specialised for absorption, and these new models provide an opportunity to further investigate the structure and function of tuft cells.

  8. Cell cycle regulation in human embryonic stem cells: links to adaptation to cell culture.

    Science.gov (United States)

    Barta, Tomas; Dolezalova, Dasa; Holubcova, Zuzana; Hampl, Ales

    2013-03-01

    Cell cycle represents not only a tightly orchestrated mechanism of cell replication and cell division but it also plays an important role in regulation of cell fate decision. Particularly in the context of pluripotent stem cells or multipotent progenitor cells, regulation of cell fate decision is of paramount importance. It has been shown that human embryonic stem cells (hESCs) show unique cell cycle characteristics, such as short doubling time due to abbreviated G1 phase; these properties change with the onset of differentiation. This review summarizes the current understanding of cell cycle regulation in hESCs. We discuss cell cycle properties as well as regulatory machinery governing cell cycle progression of undifferentiated hESCs. Additionally, we provide evidence that long-term culture of hESCs is accompanied by changes in cell cycle properties as well as configuration of several cell cycle regulatory molecules.

  9. The cell cycle as a brake for β-cell regeneration from embryonic stem cells.

    Science.gov (United States)

    El-Badawy, Ahmed; El-Badri, Nagwa

    2016-01-13

    The generation of insulin-producing β cells from stem cells in vitro provides a promising source of cells for cell transplantation therapy in diabetes. However, insulin-producing cells generated from human stem cells show deficiency in many functional characteristics compared with pancreatic β cells. Recent reports have shown molecular ties between the cell cycle and the differentiation mechanism of embryonic stem (ES) cells, assuming that cell fate decisions are controlled by the cell cycle machinery. Both β cells and ES cells possess unique cell cycle machinery yet with significant contrasts. In this review, we compare the cell cycle control mechanisms in both ES cells and β cells, and highlight the fundamental differences between pluripotent cells of embryonic origin and differentiated β cells. Through critical analysis of the differences of the cell cycle between these two cell types, we propose that the cell cycle of ES cells may act as a brake for β-cell regeneration. Based on these differences, we discuss the potential of modulating the cell cycle of ES cells for the large-scale generation of functionally mature β cells in vitro. Further understanding of the factors that modulate the ES cell cycle will lead to new approaches to enhance the production of functional mature insulin-producing cells, and yield a reliable system to generate bona fide β cells in vitro.

  10. Peptidomic analysis of human cell lines

    Science.gov (United States)

    Gelman, Julia S.; Sironi, Juan; Castro, Leandro M.; Ferro, Emer S.; Fricker, Lloyd D.

    2011-01-01

    Peptides have been proposed to function in intracellular signaling within the cytosol. Although cytosolic peptides are considered to be highly unstable, a large number of peptides have been detected in mouse brain and other biological samples. In the present study, we evaluated the peptidome of three diverse cell lines: SH-SY5Y, MCF7, and HEK293 cells. A comparison of the peptidomes revealed considerable overlap in the identity of the peptides found in each cell line. The majority of the observed peptides are not derived from the most abundant or least stable proteins in the cell, and approximately half of the cellular peptides correspond to the N- or C- termini of the precursor proteins. Cleavage site analysis revealed a preference for hydrophobic residues in the P1 position. Quantitative peptidomic analysis indicated that the levels of most cellular peptides are not altered in response to elevated intracellular calcium, suggesting that calpain is not responsible for their production. The similarity of the peptidomes of the three cell lines and the lack of correlation with the predicted cellular degradome implies the selective formation or retention of these peptides, consistent with the hypothesis that they are functional in the cells. PMID:21204522

  11. Cell cycle regulation of hematopoietic stem or progenitor cells.

    Science.gov (United States)

    Hao, Sha; Chen, Chen; Cheng, Tao

    2016-05-01

    The highly regulated process of blood production is achieved through the hierarchical organization of hematopoietic stem cell (HSC) subsets and their progenies, which differ in self-renewal and differentiation potential. Genetic studies in mice have demonstrated that cell cycle is tightly controlled by the complex interplay between extrinsic cues and intrinsic regulatory pathways involved in HSC self-renewal and differentiation. Deregulation of these cellular programs may transform HSCs or hematopoietic progenitor cells (HPCs) into disease-initiating stem cells, and can result in hematopoietic malignancies such as leukemia. While previous studies have shown roles for some cell cycle regulators and related signaling pathways in HSCs and HPCs, a more complete picture regarding the molecular mechanisms underlying cell cycle regulation in HSCs or HPCs is lacking. Based on accumulated studies in this field, the present review introduces the basic components of the cell cycle machinery and discusses their major cellular networks that regulate the dormancy and cell cycle progression of HSCs. Knowledge on this topic would help researchers and clinicians to better understand the pathogenesis of relevant blood disorders and to develop new strategies for therapeutic manipulation of HSCs.

  12. Breast cancer cell lines: friend or foe?

    International Nuclear Information System (INIS)

    Burdall, Sarah E; Hanby, Andrew M; Lansdown, Mark RJ; Speirs, Valerie

    2003-01-01

    The majority of breast cancer research is conducted using established breast cancer cell lines as in vitro models. An alternative is to use cultures established from primary breast tumours. Here, we discuss the pros and cons of using both of these models in translational breast cancer research

  13. (Asteraceae) Fraction against Human Cancer Cell Lines

    African Journals Online (AJOL)

    Purpose: To investigate the anti-proliferative and apoptotic activity of crude and dichloromethane fraction of A. sieberi against seven cancer cell lines (Colo20, HCT116, DLD, MCF7, Jurkat, HepG2 and L929). Methods: A. sieberi was extracted with methanol and further purification was carried out using liquidliquid extraction ...

  14. Modeling of SONOS Memory Cell Erase Cycle

    Science.gov (United States)

    Phillips, Thomas A.; MacLeod, Todd C.; Ho, Fat H.

    2011-01-01

    Utilization of Silicon-Oxide-Nitride-Oxide-Silicon (SONOS) nonvolatile semiconductor memories as a flash memory has many advantages. These electrically erasable programmable read-only memories (EEPROMs) utilize low programming voltages, have a high erase/write cycle lifetime, are radiation hardened, and are compatible with high-density scaled CMOS for low power, portable electronics. In this paper, the SONOS memory cell erase cycle was investigated using a nonquasi-static (NQS) MOSFET model. Comparisons were made between the model predictions and experimental data.

  15. SHP1-mediated cell cycle redistribution inhibits radiosensitivity of non-small cell lung cancer

    International Nuclear Information System (INIS)

    Cao, Rubo; Ding, Qian; Li, Pindong; Xue, Jun; Zou, Zhenwei; Huang, Jing; Peng, Gang

    2013-01-01

    Radioresistance is the common cause for radiotherapy failure in non-small cell lung cancer (NSCLC), and the degree of radiosensitivity of tumor cells is different during different cell cycle phases. The objective of the present study was to investigate the effects of cell cycle redistribution in the establishment of radioresistance in NSCLC, as well as the signaling pathway of SH2 containing Tyrosine Phosphatase (SHP1). A NSCLC subtype cell line, radioresistant A549 (A549S1), was induced by high-dose hypofractionated ionizing radiations. Radiosensitivity-related parameters, cell cycle distribution and expression of cell cycle-related proteins and SHP1 were investigated. siRNA was designed to down-regulate SHP1expression. Compared with native A549 cells, the proportion of cells in the S phase was increased, and cells in the G0/G1 phase were consequently decreased, however, the proportion of cells in the G2/M phase did not change in A549S1 cells. Moreover, the expression of SHP1, CDK4 and CylinD1 were significantly increased, while p16 was significantly down-regulated in A549S1 cells compared with native A549 cells. Furthermore, inhibition of SHP1 by siRNA increased the radiosensitivity of A549S1 cells, induced a G0/G1 phase arrest, down-regulated CDK4 and CylinD1expressions, and up-regulated p16 expression. SHP1 decreases the radiosensitivity of NSCLC cells through affecting cell cycle distribution. This finding could unravel the molecular mechanism involved in NSCLC radioresistance

  16. Radiation sensitivity of Merkel cell carcinoma cell lines

    Energy Technology Data Exchange (ETDEWEB)

    Leonard, J.H.; Ramsay, J.R.; Birrell, G.W. [Queensland Institute of Medical Research (Australia)] [and others

    1995-07-30

    Merkel cell carcinoma (MCC), being a small cell carcinoma, would be expected to be sensitive to radiation. Clinical analysis of patients at our center, especially those with macroscopic disease, would suggest the response is quite variable. We have recently established a number of MCC cell lines from patients prior to radiotherapy, and for the first time are in a position to determine their sensitivity under controlled conditions. Some of the MCC lines grew as suspension cultures and could not be single cell cloned; therefore, it was not possible to use clonogenic survival for all cell lines. A tetrazolium based (MTT) assay was used for these lines, to estimate cell growth after {gamma} irradiation. Control experiments were conducted on lymphoblastoid cell lines (LCL) and the adherent MCC line, MCC13, to demonstrate that the two assays were comparable under the conditions used. We have examined cell lines from MCC, small cell lung cancer (SCLC), malignant melanomas, Epstein Barr virus (EBV) transformed lymphocytes (LCL), and skin fibroblasts for their sensitivity to {gamma} irradiation using both clonogenic cell survival and MTT assays. The results show that the tumor cell lines have a range of sensitivities, with melanoma being more resistant (surviving fraction at 2 Gy (SF2) 0.57 and 0.56) than the small cell carcinoma lines, MCC (SF2 range 0.21-0.45, mean SF2 0.30, n = 8) and SCLC (SF2 0.31). Fibroblasts were the most sensitive (SF2 0.13-0.20, mean 0.16, n = 5). The MTT assay, when compared to clonogenic assay for the MCC13 adherent line and the LCL, gave comparable results under the conditions used. Both assays gave a range of SF2 values for the MCC cell lines, suggesting that these cancers would give a heterogeneous response in vivo. The results with the two derivative clones of MCC14 (SF2 for MCC14/1 0.38, MCC14/2 0.45) would further suggest that some of them may develop resistance during clonogenic evolution. 25 refs., 3 figs., 1 tab.

  17. Radiation sensitivity of Merkell cell carcinoma cell lines

    International Nuclear Information System (INIS)

    Leonard, J. Helen; Ramsay, Jonathan R.; Kearsley, John H.; Birrell, Geoff W.

    1995-01-01

    Purpose: Merkel cell carcinoma (MCC), being a small cell carcinoma, would be expected to be sensitive to radiation. Clinical analysis of patients at our center, especially those with macroscopic disease, would suggest the response is quite variable. We have recently established a number of MCC cell lines from patients prior to radiotherapy, and for the first time are in a position to determine their sensitivity under controlled conditions. Methods and Materials: Some of the MCC lines grew as suspension cultures and could not be single cell cloned; therefore, it was not possible to use clonogenic survival for all cell lines. A tetrazolium based (MTT) assay was used for these lines, to estimate cell growth after γ irradiation. Control experiments were conducted on lymphoblastoid cell lines (LCL) and the adherent MCC line, MCC13, to demonstrate that the two assays were comparable under the conditions used. Results: We have examined cell lines from MCC, small cell lung cancer (SCLC), malignant melanomas, Epstein Barr virus (EBV) transformed lymphocytes (LCL), and skin fibroblasts for their sensitivity to γ irradiation using both clonogenic cell survival and MTT assays. The results show that the tumor cell lines have a range of sensitivities, with melanoma being more resistant (surviving fraction at 2 Gy (SF2) 0.57 and 0.56) than the small cell carcinoma lines, MCC (SF2 range 0.21-0.45, mean SF2 0.30, n = 8) and SCLC (SF2 0.31). Fibroblasts were the most sensitive (SF2 0.13-0.20, mean 0.16, n = 5). The MTT assay, when compared to clonogenic assay for the MCC13 adherent line and the LCL, gave comparable results under the conditions used. Conclusion: Both assays gave a range of SF2 values for the MCC cell lines, suggesting that these cancers would give a heterogeneous response in vivo. The results with the two derivative clones of MCC14 (SF2 for MCC14/1 0.38, MCC14/2 0.45) would further suggest that some of them may develop resistance during clonogenic evolution

  18. Snail regulates cell survival and inhibits cellular senescence in human metastatic prostate cancer cell lines.

    Science.gov (United States)

    Emadi Baygi, Modjtaba; Soheili, Zahra Soheila; Schmitz, Ingo; Sameie, Shahram; Schulz, Wolfgang A

    2010-12-01

    The epithelial-mesenchymal transition (EMT) is regarded as an important step in cancer metastasis. Snail, a master regulator of EMT, has been recently proposed to act additionally as a cell survival factor and inducer of motility. We have investigated the function of Snail (SNAI1) in prostate cancer cells by downregulating its expression via short (21-mer) interfering RNA (siRNA) and measuring the consequences on EMT markers, cell viability, death, cell cycle, senescence, attachment, and invasivity. Of eight carcinoma cell lines, the prostate carcinoma cell lines LNCaP and PC-3 showed the highest and moderate expression of SNAI1 mRNA, respectively, as measured by quantitative RT-PCR. Long-term knockdown of Snail induced a severe decline in cell numbers in LNCaP and PC-3 and caspase activity was accordingly enhanced in both cell lines. In addition, suppression of Snail expression induced senescence in LNCaP cells. SNAI1-siRNA-treated cells did not tolerate detachment from the extracellular matrix, probably due to downregulation of integrin α6. Expression of E-cadherin, vimentin, and fibronectin was also affected. Invasiveness of PC-3 cells was not significantly diminished by Snail knockdown. Our data suggest that Snail acts primarily as a survival factor and inhibitor of cellular senescence in prostate cancer cell lines. We therefore propose that Snail can act as early driver of prostate cancer progression.

  19. Mast cells dysregulate apoptotic and cell cycle genes in mucosal squamous cell carcinoma

    Directory of Open Access Journals (Sweden)

    Davis Paul

    2006-12-01

    Full Text Available Abstract Background Mucosal squamous cell carcinoma of the head and neck is a disease of high mortality and morbidity. Interactions between the squamous cell carcinoma and the host's local immunity, and how the latter contributes to the biological behavior of the tumor are unclear. In vivo studies have demonstrated sequential mast cell infiltration and degranulation during squamous cell carcinogenesis. The degree of mast cell activation correlates closely with distinct phases of hyperkeratosis, dysplasia, carcinoma in-situ and invasive carcinoma. However, the role of mast cells in carcinogenesis is unclear. Aim This study explores the effects of mast cells on the proliferation and gene expression profile of mucosal squamous cell carcinoma using human mast cell line (HMC-1 and human glossal squamous cell carcinoma cell line (SCC25. Methods HMC-1 and SCC25 were co-cultured in a two-compartment chamber, separated by a polycarbonate membrane. HMC-1 was stimulated to degranulate with calcium ionophore A23187. The experiments were done in quadruplicate. Negative controls were established where SCC25 were cultured alone without HMC-1. At 12, 24, 48 and 72 hours, proliferation and viability of SCC25 were assessed with MTT colorimetric assay. cDNA microarray was employed to study differential gene expression between co-cultured and control SCC25. Results HMC-1/SCC25 co-culture resulted in suppression of growth rate for SCC-25 (34% compared with 110% for the control by 72 hours, p Conclusion We show that mast cells have a direct inhibitory effect on the proliferation of mucosal squamous cell carcinoma in vitro by dysregulating key genes in apoptosis and cell cycle control.

  20. Identification of genes associated with cisplatin resistance in human oral squamous cell carcinoma cell line

    International Nuclear Information System (INIS)

    Zhang, Ping; Zhang, Zhiyuan; Zhou, Xiaojian; Qiu, Weiliu; Chen, Fangan; Chen, Wantao

    2006-01-01

    Cisplatin is widely used for chemotherapy of head and neck squamous cell carcinoma. However, details of the molecular mechanism responsible for cisplatin resistance are still unclear. The aim of this study was to identify the expression of genes related to cisplatin resistance in oral squamous cell carcinoma cells. A cisplatin-resistant cell line, Tca/cisplatin, was established from a cisplatin-sensitive cell line, Tca8113, which was derived from moderately-differentiated tongue squamous cell carcinoma. Global gene expression in this resistant cell line and its sensitive parent cell line was analyzed using Affymetrix HG-U95Av2 microarrays. Candidate genes involved in DNA repair, the MAP pathway and cell cycle regulation were chosen to validate the microarray analysis results. Cell cycle distribution and apoptosis following cisplatin exposure were also investigated. Cisplatin resistance in Tca/cisplatin cells was stable for two years in cisplatin-free culture medium. The IC50 for cisplatin in Tca/cisplatin was 6.5-fold higher than that in Tca8113. Microarray analysis identified 38 genes that were up-regulated and 25 that were down-regulated in this cell line. Some were novel candidates, while others are involved in well-characterized mechanisms that could be relevant to cisplatin resistance, such as RECQL for DNA repair and MAP2K6 in the MAP pathway; all the genes were further validated by Real-time PCR. The cell cycle-regulated genes CCND1 and CCND3 were involved in cisplatin resistance; 24-hour exposure to 10 μM cisplatin induced a marked S phase block in Tca/cisplatin cells but not in Tca8113 cells. The Tca8113 cell line and its stable drug-resistant variant Tca/cisplatin provided a useful model for identifying candidate genes responsible for the mechanism of cisplatin resistance in oral squamous cell carcinoma. Our data provide a useful basis for screening candidate targets for early diagnosis and further intervention in cisplatin resistance

  1. Identification of genes associated with cisplatin resistance in human oral squamous cell carcinoma cell line

    Directory of Open Access Journals (Sweden)

    Zhang Ping

    2006-09-01

    Full Text Available Abstract Background Cisplatin is widely used for chemotherapy of head and neck squamous cell carcinoma. However, details of the molecular mechanism responsible for cisplatin resistance are still unclear. The aim of this study was to identify the expression of genes related to cisplatin resistance in oral squamous cell carcinoma cells. Methods A cisplatin-resistant cell line, Tca/cisplatin, was established from a cisplatin-sensitive cell line, Tca8113, which was derived from moderately-differentiated tongue squamous cell carcinoma. Global gene expression in this resistant cell line and its sensitive parent cell line was analyzed using Affymetrix HG-U95Av2 microarrays. Candidate genes involved in DNA repair, the MAP pathway and cell cycle regulation were chosen to validate the microarray analysis results. Cell cycle distribution and apoptosis following cisplatin exposure were also investigated. Results Cisplatin resistance in Tca/cisplatin cells was stable for two years in cisplatin-free culture medium. The IC50 for cisplatin in Tca/cisplatin was 6.5-fold higher than that in Tca8113. Microarray analysis identified 38 genes that were up-regulated and 25 that were down-regulated in this cell line. Some were novel candidates, while others are involved in well-characterized mechanisms that could be relevant to cisplatin resistance, such as RECQL for DNA repair and MAP2K6 in the MAP pathway; all the genes were further validated by Real-time PCR. The cell cycle-regulated genes CCND1 and CCND3 were involved in cisplatin resistance; 24-hour exposure to 10 μM cisplatin induced a marked S phase block in Tca/cisplatin cells but not in Tca8113 cells. Conclusion The Tca8113 cell line and its stable drug-resistant variant Tca/cisplatin provided a useful model for identifying candidate genes responsible for the mechanism of cisplatin resistance in oral squamous cell carcinoma. Our data provide a useful basis for screening candidate targets for early diagnosis

  2. Dihydromyricetin induces cell cycle arrest and apoptosis in melanoma SK-MEL-28 cells.

    Science.gov (United States)

    Zeng, Guofang; Liu, Jie; Chen, Hege; Liu, Bin; Zhang, Qingyu; Li, Mingyi; Zhu, Runzhi

    2014-06-01

    Dihydromyricetin (DHM) exhibits multiple pharmacological activities; however, the role of DHM in anti-melanoma activities and the underlying molecular mechanisms are unclear. The aim of the present study was to evaluate the effects of DHM on cell proliferation, cell cycle distribution and apoptosis in the human melanoma SK-MEL-28 cell line, and to explore the related mechanisms. The effect of DHM on cell proliferation was investigated by MTT assay, and cell cycle distribution was determined by flow cytometry. TUNEL assay was used to evaluate DHM-mediated apoptosis, and western blotting was applied to examine expression levels of p53, p21, Cdc25A, Cdc2, P-Cdc2, Bax, IKK-α, NF-κB p65, p38 and P-p38 proteins. The results revealed that DHM suppressed cell proliferation of SK-MEL-28 cells in a concentration- and time-dependent manner, and caused cell cycle arrest at the G1/S phase. DHM increased the production of p53 and p21 proteins and downregulated the production of Cdc25A, Cdc2 and P-Cdc2 proteins, which induced cell cycle arrest. Additionally, DHM significantly induced the apoptosis of SK-MEL-28 cells, and enhanced the expression levels of Bax proteins and decreased the protein levels of IKK-α, NF-κB (p65) and P-p38. The results suggest that DHM may be a novel and effective candidate agent to inhibit the growth of melanoma.

  3. A universal mammalian vaccine cell line substrate.

    Directory of Open Access Journals (Sweden)

    Jackelyn Murray

    Full Text Available Using genome-wide small interfering RNA (siRNA screens for poliovirus, influenza A virus and rotavirus, we validated the top 6 gene hits PV, RV or IAV to search for host genes that when knocked-down (KD enhanced virus permissiveness and replication over wild type Vero cells or HEp-2 cells. The enhanced virus replication was tested for 12 viruses and ranged from 2-fold to >1000-fold. There were variations in virus-specific replication (strain differences across the cell lines examined. Some host genes (CNTD2, COQ9, GCGR, NDUFA9, NEU2, PYCR1, SEC16G, SVOPL, ZFYVE9, and ZNF205 showed that KD resulted in enhanced virus replication. These findings advance platform-enabling vaccine technology, the creation of diagnostic cells substrates, and are informative about the host mechanisms that affect virus replication in mammalian cells.

  4. The effects of antiepileptic drugs on the growth of glioblastoma cell lines

    OpenAIRE

    Lee, Ching-Yi; Lai, Hung-Yi; Chiu, Angela; Chan, She-Hung; Hsiao, Ling-Ping; Lee, Shih-Tseng

    2016-01-01

    To determine the effects of antiepileptic drug compounds on glioblastoma cellular growth, we exposed glioblastoma cell lines to select antiepileptic drugs. The effects of selected antiepileptic drugs on glioblastoma cells were measured by MTT assay. For compounds showing significant inhibition, cell cycle analysis was performed. Statistical analysis was performed using SPSS. The antiepileptic compounds selected for screening included carbamazepine, ethosuximide, gabapentin, lamotrigine, levet...

  5. Akt1 intramitochondrial cycling is a crucial step in the redox modulation of cell cycle progression.

    Directory of Open Access Journals (Sweden)

    Valeria Gabriela Antico Arciuch

    2009-10-01

    Full Text Available Akt is a serine/threonine kinase involved in cell proliferation, apoptosis, and glucose metabolism. Akt is differentially activated by growth factors and oxidative stress by sequential phosphorylation of Ser(473 by mTORC2 and Thr(308 by PDK1. On these bases, we investigated the mechanistic connection of H(2O(2 yield, mitochondrial activation of Akt1 and cell cycle progression in NIH/3T3 cell line with confocal microscopy, in vivo imaging, and directed mutagenesis. We demonstrate that modulation by H(2O(2 entails the entrance of cytosolic P-Akt1 Ser(473 to mitochondria, where it is further phosphorylated at Thr(308 by constitutive PDK1. Phosphorylation of Thr(308 in mitochondria determines Akt1 passage to nuclei and triggers genomic post-translational mechanisms for cell proliferation. At high H(2O(2, Akt1-PDK1 association is disrupted and P-Akt1 Ser(473 accumulates in mitochondria in detriment to nuclear translocation; accordingly, Akt1 T308A is retained in mitochondria. Low Akt1 activity increases cytochrome c release to cytosol leading to apoptosis. As assessed by mass spectra, differential H(2O(2 effects on Akt1-PDK interaction depend on the selective oxidation of Cys(310 to sulfenic or cysteic acids. These results indicate that Akt1 intramitochondrial-cycling is central for redox modulation of cell fate.

  6. Low dose perfluorooctanoate exposure promotes cell proliferation in a human non-tumor liver cell line

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Hongxia; Cui, Ruina [Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101 (China); Guo, Xuejiang [State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing 210029 (China); Hu, Jiayue [Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101 (China); Dai, Jiayin, E-mail: daijy@ioz.ac.cn [Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101 (China)

    2016-08-05

    Highlights: • Differential expression of proteins induced by PFOA in HL-7702 was identified. • Most of the differentially expressed proteins are related to cell proliferation. • A low dose of PFOA stimulates HL-7702 cell proliferation. • A high dose of PFOA inhibits HL-7702 cell proliferation. - Abstract: Perfluorooctanoate (PFOA) is a well-known persistent organic pollutant widely found in the environment, wildlife and humans. Medical surveillance and experimental studies have investigated the potential effects of PFOA on human livers, but the hepatotoxicity of PFOA on humans and its underlying mechanism remain to be clarified. We exposed a human liver cell line (HL-7702) to 50 μM PFOA for 48 h and 96 h, and identified 111 significantly differentially expressed proteins by iTRAQ analysis. A total of 46 proteins were related to cell proliferation and apoptosis. Through further analysis of the cell cycle, apoptosis and their related proteins, we found that low doses of PFOA (50–100 μM) promoted cell proliferation and numbers by promoting cells from the G1 to S phases, whereas high doses of PFOA (200–400 μM) led to reduced HL-7702 cell numbers compared with that of the control mainly due to cell cycle arrest in the G0/G1 phase. To our knowledge, this is the first report on the promotion of cell cycle progression in human cells following PFOA exposure.

  7. Low dose perfluorooctanoate exposure promotes cell proliferation in a human non-tumor liver cell line

    International Nuclear Information System (INIS)

    Zhang, Hongxia; Cui, Ruina; Guo, Xuejiang; Hu, Jiayue; Dai, Jiayin

    2016-01-01

    Highlights: • Differential expression of proteins induced by PFOA in HL-7702 was identified. • Most of the differentially expressed proteins are related to cell proliferation. • A low dose of PFOA stimulates HL-7702 cell proliferation. • A high dose of PFOA inhibits HL-7702 cell proliferation. - Abstract: Perfluorooctanoate (PFOA) is a well-known persistent organic pollutant widely found in the environment, wildlife and humans. Medical surveillance and experimental studies have investigated the potential effects of PFOA on human livers, but the hepatotoxicity of PFOA on humans and its underlying mechanism remain to be clarified. We exposed a human liver cell line (HL-7702) to 50 μM PFOA for 48 h and 96 h, and identified 111 significantly differentially expressed proteins by iTRAQ analysis. A total of 46 proteins were related to cell proliferation and apoptosis. Through further analysis of the cell cycle, apoptosis and their related proteins, we found that low doses of PFOA (50–100 μM) promoted cell proliferation and numbers by promoting cells from the G1 to S phases, whereas high doses of PFOA (200–400 μM) led to reduced HL-7702 cell numbers compared with that of the control mainly due to cell cycle arrest in the G0/G1 phase. To our knowledge, this is the first report on the promotion of cell cycle progression in human cells following PFOA exposure.

  8. Curcumin Induces Autophagy, Apoptosis, and Cell Cycle Arrest in Human Pancreatic Cancer Cells

    Directory of Open Access Journals (Sweden)

    Yaping Zhu

    2017-01-01

    Full Text Available Objective. Curcumin is an active extract from turmeric. The aim of this study was to identify the underlying mechanism of curcumin on PCa cells and the role of autophagy in this process. Methods. The inhibitory effect of curcumin on the growth of PANC1 and BxPC3 cell lines was detected by CCK-8 assay. Cell cycle distribution and apoptosis were tested by flow cytometry. Autophagosomes were tested by cell immunofluorescence assay. The protein expression was detected by Western blot. The correlation between LC3II/Bax and cell viability was analyzed. Results. Curcumin inhibited the cell proliferation in a dose- and time-dependent manner. Curcumin could induce cell cycle arrest at G2/M phase and apoptosis of PCa cells. The autophagosomes were detected in the dosing groups. Protein expression of Bax and LC3II was upregulated, while Bcl2 was downregulated in the high dosing groups of curcumin. There was a significant negative correlation between LC3II/Bax and cell viability. Conclusions. Autophagy could be triggered by curcumin in the treatment of PCa. Apoptosis and cell cycle arrest also participated in this process. These findings imply that curcumin is a multitargeted agent for PCa cells. In addition, autophagic cell death may predominate in the high concentration groups of curcumin.

  9. Tcf3 and cell cycle factors contribute to butyrate resistance in colorectal cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Chiaro, Christopher, E-mail: cchiaro@tcmedc.org [Department of Basic Sciences, The Commonwealth Medical College, 525 Pine Street, Scranton, PA 18509 (United States); Lazarova, Darina L., E-mail: dlazarova@tcmedc.org [Department of Basic Sciences, The Commonwealth Medical College, 525 Pine Street, Scranton, PA 18509 (United States); Bordonaro, Michael, E-mail: mbordonaro@tcmedc.org [Department of Basic Sciences, The Commonwealth Medical College, 525 Pine Street, Scranton, PA 18509 (United States)

    2012-11-09

    Highlights: Black-Right-Pointing-Pointer We investigate mechanisms responsible for butyrate resistance in colon cancer cells. Black-Right-Pointing-Pointer Tcf3 modulates butyrate's effects on Wnt activity and cell growth in resistant cells. Black-Right-Pointing-Pointer Tcf3 modulation of butyrate's effects differ by cell context. Black-Right-Pointing-Pointer Cell cycle factors are overexpressed in the resistant cells. Black-Right-Pointing-Pointer Reversal of altered gene expression can enhance the anti-cancer effects of butyrate. -- Abstract: Butyrate, a fermentation product of dietary fiber, inhibits clonal growth in colorectal cancer (CRC) cells dependent upon the fold induction of Wnt activity. We have developed a CRC cell line (HCT-R) that, unlike its parental cell line, HCT-116, does not respond to butyrate exposure with hyperactivation of Wnt signaling and suppressed clonal growth. PCR array analyses revealed Wnt pathway-related genes, the expression of which differs between butyrate-sensitive HCT-116 CRC cells and their butyrate-resistant HCT-R cell counterparts. We identified overexpression of Tcf3 as being partially responsible for the butyrate-resistant phenotype, as this DNA-binding protein suppresses the hyperinduction of Wnt activity by butyrate. Consequently, Tcf3 knockdown in HCT-R cells restores their sensitivity to the effects of butyrate on Wnt activity and clonal cell growth. Interestingly, the effects of overexpressed Tcf3 differ between HCT-116 and HCT-R cells; thus, in HCT-116 cells Tcf3 suppresses proliferation without rendering the cells resistant to butyrate. In HCT-R cells, however, the overexpression of Tcf3 inhibits Wnt activity, and the cells are still able to proliferate due to the higher expression levels of cell cycle factors, particularly those driving the G{sub 1} to S transition. Knowledge of the molecular mechanisms determining the variable sensitivity of CRC cells to butyrate may assist in developing approaches that

  10. Tcf3 and cell cycle factors contribute to butyrate resistance in colorectal cancer cells

    International Nuclear Information System (INIS)

    Chiaro, Christopher; Lazarova, Darina L.; Bordonaro, Michael

    2012-01-01

    Highlights: ► We investigate mechanisms responsible for butyrate resistance in colon cancer cells. ► Tcf3 modulates butyrate’s effects on Wnt activity and cell growth in resistant cells. ► Tcf3 modulation of butyrate’s effects differ by cell context. ► Cell cycle factors are overexpressed in the resistant cells. ► Reversal of altered gene expression can enhance the anti-cancer effects of butyrate. -- Abstract: Butyrate, a fermentation product of dietary fiber, inhibits clonal growth in colorectal cancer (CRC) cells dependent upon the fold induction of Wnt activity. We have developed a CRC cell line (HCT-R) that, unlike its parental cell line, HCT-116, does not respond to butyrate exposure with hyperactivation of Wnt signaling and suppressed clonal growth. PCR array analyses revealed Wnt pathway-related genes, the expression of which differs between butyrate-sensitive HCT-116 CRC cells and their butyrate-resistant HCT-R cell counterparts. We identified overexpression of Tcf3 as being partially responsible for the butyrate-resistant phenotype, as this DNA-binding protein suppresses the hyperinduction of Wnt activity by butyrate. Consequently, Tcf3 knockdown in HCT-R cells restores their sensitivity to the effects of butyrate on Wnt activity and clonal cell growth. Interestingly, the effects of overexpressed Tcf3 differ between HCT-116 and HCT-R cells; thus, in HCT-116 cells Tcf3 suppresses proliferation without rendering the cells resistant to butyrate. In HCT-R cells, however, the overexpression of Tcf3 inhibits Wnt activity, and the cells are still able to proliferate due to the higher expression levels of cell cycle factors, particularly those driving the G 1 to S transition. Knowledge of the molecular mechanisms determining the variable sensitivity of CRC cells to butyrate may assist in developing approaches that prevent or reverse butyrate resistance.

  11. Analysis of cell-cycle regulation following exposure of lung-derived cells to γ-rays

    Science.gov (United States)

    Trani, D.; Lucchetti, C.; Cassone, M.; D'Agostino, L.; Caputi, M.; Giordano, A.

    Acute exposure of mammalian cells to ionizing radiation results in a delay of cell-cycle progression and/or augmentation of apoptosis. Following ionizing radiation-induced DNA damage, cell-cycle arrest in the G1- or G2-phase of the cell-cycle prevents or delays DNA replication or mitosis, providing time for the DNA repair machinery to exert its function. Deregulation or failing of cell-cycle checkpoints and/or DNA repair mechanisms may lead normal cells bearing chromosome mutations to acquire neoplastic autonomy, which in turn can trigger the onset of cancer. Existing studies have focused on the impact of p53 status on the radiation response of lung cancer (LC) cell lines in terms of both cell-cycle regulation and apoptosis, while no comparative studies have been performed on the radiation response of lung derived normal and cancerous epithelial cells. To investigate the radiation response in normal and cancerous phenotypes, along with the role and impact of p53 status, and possible correlations with pRb/p105 or other proteins involved in carcinogenesis and cell-cycle regulation, we selected two lung-derived epithelial cell lines, one normal (NL20, p53 wild-type) and one non-small cell lung cancer (NSCLC), H358 (known to be p53-deficient). We compared the levels of γ-induced cell proliferation ability, cell-cycle arrest, apoptotic index, and expression levels of cell-cycle regulating and regulated proteins. The different cell sensitivity, apoptotic response and protein expression profiles resulting from our study for NL20 and H358 cells suggest that still unknown mechanisms involving p53, pRb/p105 and their target molecules might play a pivotal role in determining cell sensitivity and resistance upon exposure to ionizing radiation.

  12. Cellular radiosensitivity of small-cell lung cancer cell lines

    DEFF Research Database (Denmark)

    Krarup, M; Poulsen, H S; Spang-Thomsen, M

    1997-01-01

    PURPOSE: The objective of this study was to determine the radiobiological characteristics of a panel of small-cell lung cancer (SCLC) cell lines by use of a clonogenic assay. In addition, we tested whether comparable results could be obtained by employing a growth extrapolation method based...

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

    Directory of Open Access Journals (Sweden)

    Mei-Yin Chang

    2015-11-01

    Full Text Available 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.

  14. Antiproliferative Effects of Selected Chemotherapeutics in Human Ovarian Cancer Cell Line A2780

    Directory of Open Access Journals (Sweden)

    Kateřina Caltová

    2012-01-01

    Full Text Available The aim of our study was to determine the effect of selected cytostatics on a human ovarian cancer cell line A2780 as a model system for ovarian cancer treatment. This cell line is considered cisplatin-sensitive. Panel of tested cytostatics included cisplatin, paclitaxel, carboplatin, gemcitabine, topotecan and etoposide. These cytostatics have a different mechanism of action. To evaluate cytotoxic potential of the tested compounds, the methods measuring various toxicological endpoints were employed including morphological studies, MTT assay, dynamic monitoring of cell proliferation with xCELLigence, cell cycle analysis, caspase 3 activity and expression of proteins involved in cell cycle regulation and cell death. The A270 cell line showed different sensitivity towards the selected cytostatics, the highest cytotoxic effect was associated with paclitaxel and topotecan.

  15. Cell lines radiosensitization of thyroid cancer by histone deacetylase inhibitors

    International Nuclear Information System (INIS)

    Perona, M; Dagrosa, M A; Rossich, L; Casal, M; Pisarev, M A; Thomasz, L; Juvenal G J

    2012-01-01

    Introduction: Thyroid cancer is the most common endocrine neoplasia. Surgical resection and radioactive iodine is an effective treatment for well-differentiated tumors. Histone deacetylase inhibitors (HDAC-I) are agents that cause hyperacetylation of histone proteins and as a consequence remodeling of chromatin structure. They can induce growth arrest, differentiation and apoptotic cell death in different tumor cells. The use of HDAC-I agents could be of utility to enhance the response to external radiation therapy of those thyroid cancers that are refractory to most conventional therapeutic treatments. Objective: To study the effect of HDAC-I as radiosensitizers for the treatment of thyroid cancer and their ability to induce differentiation of thyroid cancer cells. Materials and methods: The human thyroid follicular (WRO) and papillary (TPC-1) carcinoma cell lines were seeded and incubated with increasing doses (0, 0.3, 0.5, 1 and 1.5 mM) of the HDAC-I sodium butirate (NaB) and valproic acid (VA) to evaluate cell proliferation and iodide uptake. Cells were irradiated with a 60 Co γ-ray source (1 ± 5% Gy/min) and postirradiation survival was quantified with the colony formation assay. Survival fraction at 2 Gy (SF2) was calculated for each cell line. Cell cycle and cell death were evaluated at a dose of 3 Gy. Iodide uptake, PCR analysis and transient transfection studies were performed. Results: Cell proliferation was not significantly suppressed after 24 hours of incubation with both drugs at all assayed doses. Iodide uptake was not modified after incubation with HDAC-I of both cell lines. SF2 was reduced from 68 ± 1.6 % in the control WRO cells to 42 ± 3.8 % (P<0.001) in NaB-treated cells. In TPC-1 SF2 was reduced from 32 ± 1.1 % in the control cells to 24 ± 0.8 % (P<0.01). In VA-treated cells SF2 was reduced from 69 ± 0.02 % in control WRO cells to 56 ± 0.01 % (P<0.01) and from 31 ± 2 % in control TPC-1 cells to 11 ± 1 % (P<0.01). There was an arrest

  16. Measuring cell cycle progression kinetics with metabolic labeling and flow cytometry.

    Science.gov (United States)

    Fleisig, Helen; Wong, Judy

    2012-05-22

    Precise control of the initiation and subsequent progression through the various phases of the cell cycle are of paramount importance in proliferating cells. Cell cycle division is an integral part of growth and reproduction and deregulation of key cell cycle components have been implicated in the precipitating events of carcinogenesis. Molecular agents in anti-cancer therapies frequently target biological pathways responsible for the regulation and coordination of cell cycle division. Although cell cycle kinetics tend to vary according to cell type, the distribution of cells amongst the four stages of the cell cycle is rather consistent within a particular cell line due to the consistent pattern of mitogen and growth factor expression. Genotoxic events and other cellular stressors can result in a temporary block of cell cycle progression, resulting in arrest or a temporary pause in a particular cell cycle phase to allow for instigation of the appropriate response mechanism. The ability to experimentally observe the behavior of a cell population with reference to their cell cycle progression stage is an important advance in cell biology. Common procedures such as mitotic shake off, differential centrifugation or flow cytometry-based sorting are used to isolate cells at specific stages of the cell cycle. These fractionated, cell cycle phase-enriched populations are then subjected to experimental treatments. Yield, purity and viability of the separated fractions can often be compromised using these physical separation methods. As well, the time lapse between separation of the cell populations and the start of experimental treatment, whereby the fractionated cells can progress from the selected cell cycle stage, can pose significant challenges in the successful implementation and interpretation of these experiments. Other approaches to study cell cycle stages include the use of chemicals to synchronize cells. Treatment of cells with chemical inhibitors of key

  17. Establishment and characterization of 7 novel hepatocellular carcinoma cell lines from patient-derived tumor xenografts.

    Directory of Open Access Journals (Sweden)

    Hong Xin

    Full Text Available Hepatocellular carcinoma (HCC is a common cancer with poor prognosis worldwide and the molecular mechanism is not well understood. This study aimed to establish a collection of human HCC cell lines from patient-derived xenograft (PDX models. From the 20 surgical HCC sample collections, 7 tumors were successfully developed in immunodeficient mice and further established 7 novel HCC cell lines (LIXC002, LIXC003, LIXC004, LIXC006, LIXC011, LIXC012 and CPL0903 by primary culture. The characterization of cell lines was defined by morphology, growth kinetics, cell cycle, chromosome analysis, short tandem repeat (STR analysis, molecular profile, and tumorigenicity. Additionally, response to clinical chemotherapeutics was validated both in vitro and in vivo. STR analysis indicated that all cell lines were unique cells different from known cell lines and free of contamination by bacteria or mycoplasma. The other findings were quite heterogeneous between individual lines. Chromosome aberration could be found in all cell lines. Alpha-fetoprotein was overexpressed only in 3 out of 7 cell lines. 4 cell lines expressed high level of vimentin. Ki67 was strongly stained in all cell lines. mRNA level of retinoic acid induced protein 3 (RAI3 was decreased in all cell lines. The 7 novel cell lines showed variable sensitivity to 8 tested compounds. LIXC011 and CPL0903 possessed multiple drug resistance property. Sorafenib inhibited xenograft tumor growth of LIXC006, but not of LIXC012. Our results indicated that the 7 novel cell lines with low passage maintaining their clinical and pathological characters could be good tools for further exploring the molecular mechanism of HCC and anti-cancer drug screening.

  18. Cell cycle disturbances in slowly growing sublines isolated from X-irradiated L5178Y-S cell populations

    International Nuclear Information System (INIS)

    Beer, J.Z.; Bocian, E.; Budzicka, E.; Szumiel, I.; Ziemba-Zak, B.; Kopec, M.

    1974-01-01

    Cell cycle was analyzed autoradiographically in a test line of murine leukaemic lymphoblasts L5178Y-S and in two slowly growing sublines isolated from cell cultures irradiated with 300 rad of X-rays. It was found that prolongation of the cell cycle in the slowly growing sublines is connected primarily with delayed progression through G2 phase. This conclusion was further supported by results of determination of DNA content per cell in 13 slowly growing cell sublines and karyotype analysis of 18 sublines. No correlation was found between a sublines' mean doubling time and its chromosome number whereas DNA content per cell was clearly dependent on the growth rate. (author)

  19. Impact of cycling cells and cell cycle regulation on Hydra regeneration.

    Science.gov (United States)

    Buzgariu, Wanda; Wenger, Yvan; Tcaciuc, Nina; Catunda-Lemos, Ana-Paula; Galliot, Brigitte

    2018-01-15

    Hydra tissues are made from three distinct populations of stem cells that continuously cycle and pause in G2 instead of G1. To characterize the role of cell proliferation after mid-gastric bisection, we have (i) used flow cytometry and classical markers to monitor cell cycle modulations, (ii) quantified the transcriptomic regulations of 202 genes associated with cell proliferation during head and foot regeneration, and (iii) compared the impact of anti-proliferative treatments on regeneration efficiency. We confirm two previously reported events: an early mitotic wave in head-regenerating tips, when few cell cycle genes are up-regulated, and an early-late wave of proliferation on the second day, preceded by the up-regulation of 17 cell cycle genes. These regulations appear more intense after mid-gastric bisection than after decapitation, suggesting a position-dependent regulation of cell proliferation during head regeneration. Hydroxyurea, which blocks S-phase progression, delays head regeneration when applied before but not after bisection. This result is consistent with the fact that the Hydra central region is enriched in G2-paused adult stem cells, poised to divide upon injury, thus forming a necessary constitutive pro-blastema. However a prolonged exposure to hydroxyurea does not block regeneration as cells can differentiate apical structures without traversing S-phase, and also escape in few days the hydroxyurea-induced S-phase blockade. Thus Hydra head regeneration, which is a fast event, is highly plastic, relying on large stocks of adult stem cells paused in G2 at amputation time, which immediately divide to proliferate and/or differentiate apical structures even when S-phase is blocked. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  20. Study of the G2/M cell cycle checkpoint in irradiated mammary epithelial cells overexpressing Cul-4A gene

    International Nuclear Information System (INIS)

    Gupta, Anu; Yang, L.-X.; Chen, L.-C.

    2002-01-01

    Purpose: Members of the cullin gene family are known to be involved in cell cycle control. One of the cullin genes, Cul-4A, is amplified and overexpressed in breast cancer cells. This study investigates the effect of Cul-4A overexpression upon G2/M cell cycle checkpoint after DNA damage induced by either ionizing or nonionizing radiation. Methods and Materials: The normal mammary epithelial cell line MCF10A was stably transfected with full-length Cul-4A cDNA. Independent clones of MCF10A cells that overexpress Cul-4A proteins were selected and treated with either 8 Gy of ionizing radiation or 7 J/M 2 of UV radiation. The profile of cell cycle progression and the accumulation of several cell cycle proteins were analyzed. Results: We found that overexpression of Cul-4A in MCF10A cells abrogated the G2/M cell cycle checkpoint in response to DNA damage induced by ionizing irradiation, but not to DNA damage induced by nonionizing radiation. Analysis of cell cycle proteins showed that after ionizing irradiation, p53 accumulated in the mock-transfected MCF10A cells, but not in the Cul-4A transfectants. Conclusion: Our results suggest a role for Cul-4A in tumorigenesis and/or tumor progression, possibly through disruption of cell cycle control

  1. Cell cycle pathway dysregulation in human keratinocytes during chronic exposure to low arsenite.

    Science.gov (United States)

    Al-Eryani, Laila; Waigel, Sabine; Jala, Venkatakrishna; Jenkins, Samantha F; States, J Christopher

    2017-09-15

    Arsenic is naturally prevalent in the earth's crust and widely distributed in air and water. Chronic low arsenic exposure is associated with several cancers in vivo, including skin cancer, and with transformation in vitro of cell lines including immortalized human keratinocytes (HaCaT). Arsenic also is associated with cell cycle dysregulation at different exposure levels in multiple cell lines. In this work, we analyzed gene expression in HaCaT cells to gain an understanding of gene expression changes contributing to transformation at an early time point. HaCaT cells were exposed to 0 or 100nM NaAsO 2 for 7weeks. Total RNA was purified and analyzed by microarray hybridization. Differential expression with fold change≥|1.5| and p-value≤0.05 was determined using Partek Genomic Suite™ and pathway and network analyses using MetaCore™ software (FDR≤0.05). Cell cycle analysis was performed using flow cytometry. 644 mRNAs were differentially expressed. Cell cycle/cell cycle regulation pathways predominated in the list of dysregulated pathways. Genes involved in replication origin licensing were enriched in the network. Cell cycle assay analysis showed an increase in G2/M compartment in arsenite-exposed cells. Arsenite exposure induced differential gene expression indicating dysregulation of cell cycle control, which was confirmed by cell cycle analysis. The results suggest that cell cycle dysregulation is an early event in transformation manifested in cells unable to transit G2/M efficiently. Further study at later time points will reveal additional changes in gene expression related to transformation processes. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Induction of cell cycle arrest and apoptosis by Ormenis eriolepis a ...

    African Journals Online (AJOL)

    Induction of cell cycle arrest and apoptosis by Ormenis eriolepis a Morrocan endemic plant in various human cancer cell lines. Lamiae Belayachi, Clara Aceves-Luquero, Nawel Merghoub, Silvia Fernández de Mattos, Saaïd Amzazi, Priam Villalonga, Youssef Bakri ...

  3. Menadione inhibits MIBG uptake in two neuroendocrine cell lines

    NARCIS (Netherlands)

    Cornelissen, J.; Tytgat, G. A.; van den Brug, M.; van Kuilenburg, A. B.; Voûte, P. A.; van Gennip, A. H.

    1997-01-01

    In this paper we report on our studies of the effect of menadione on the uptake of MIBG in the neuroendocrine cell lines PC12 and SK-N-SH. Menadione inhibits the uptake of MIBG in both cell lines in a dose-dependent manner. Inhibition of MIBG uptake is most pronounced in the PC12 cell line.

  4. P27 in cell cycle control and cancer

    DEFF Research Database (Denmark)

    Møller, Michael Boe

    2000-01-01

    In order to survive, cells need tight control of cell cycle progression. The control mechanisms are often lost in human cancer cells. The cell cycle is driven forward by cyclin-dependent kinases (CDKs). The CDK inhibitors (CKIs) are important regulators of the CDKs. As the name implies, CKIs were...

  5. Interlink between cholesterol & cell cycle in prostate carcinoma

    Directory of Open Access Journals (Sweden)

    Govind Singh

    2017-01-01

    Interpretation & conclusions: The present findings along with increased expression of cell cycle protein cyclin E in the cell nucleus of the tumour tissue suggested the possibility of an intriguing role of cholesterol in the mechanism of cell cycle process of prostate cell proliferation.

  6. Expression of myc family oncoproteins in small-cell lung-cancer cell lines and xenografts

    DEFF Research Database (Denmark)

    Rygaard, K; Vindeløv, L L; Spang-Thomsen, M

    1993-01-01

    A number of genes have altered activity in small-cell lung cancer (SCLC), but especially genes of the myc family (c-myc, L-myc and N-myc) are expressed at high levels in SCLC. Most studies have explored expression at the mRNA level, whereas studies of myc family oncoprotein expression are sparse....... WE examined the expression of myc proto-oncogenes at the mRNA and protein level in 23 cell lines or xenografts. In the cell lines, the doubling time and the cell-cycle distribution, as determined by flow-cytometric DNA analysis, were examined to establish whether the level of myc......-myc. In general, the level of expression of c-myc and N-myc was similar at the mRNA and the protein level. Expression of c-myc was positively correlated with the proliferative index (sum of S and G2+M phases) of cell lines, but not with the population doubling time. In general, L-myc-expressing cell lines had...

  7. The Cellosaurus, a Cell-Line Knowledge Resource

    Science.gov (United States)

    Bairoch, Amos

    2018-01-01

    The Cellosaurus is a knowledge resource on cell lines. It aims to describe all cell lines used in biomedical research. Its scope encompasses both vertebrates and invertebrates. Currently, information for >100,000 cell lines is provided. For each cell line, it provides a wealth of information, cross-references, and literature citations. The Cellosaurus is available on the ExPASy server (https://web.expasy.org/cellosaurus/) and can be downloaded in a variety of formats. Among its many uses, the Cellosaurus is a key resource to help researchers identify potentially contaminated/misidentified cell lines, thus contributing to improving the quality of research in the life sciences. PMID:29805321

  8. UV-induced changes in cell cycle and gene expression within rabbit lens epithelial cells

    International Nuclear Information System (INIS)

    Sidjanin, D.; Grdina, D.; Woloschak, G.E.

    1996-01-01

    Damage to lens epithelial cells is a probable initiation process in cataract formation mediated by UV radiation. In these experiments, we investigated the effects of exposure to 254 nm radiation on cell cycle progression in the rabbit lens epithelial cell line N/N1003A. The RNA was harvested at various times following exposure to UV (254 nm) radiation and analyzed by dot-blot and northern blot hybridizations. These results revealed that during the first 6 h following exposure of the cells to UV, there was, associated with decreasing dose, a decrease in accumulation of transcripts specific for histones H3 and H4 and an increase in the mRNA encoding protein kinase C and β- and γ-actin. Using flow cytometry, we detected an accumulation of cells in G1/S phase of the cell cycle 1 h following exposure to 254 nm radiation. The observed changes in gene expression, especially the decreased accumulation of histone transcripts reported here, may play a role in UV-induced inhibition of cell cycle progression. (Author)

  9. KOH concentration effect on cycle life of nickel-hydrogen cells. III - Cycle life test

    Science.gov (United States)

    Lim, H. S.; Verzwyvelt, S. A.

    1988-01-01

    A cycle life test of Ni/H2 cells containing electrolytes of various KOH concentrations and a sintered type nickel electrode was carried out at 23 C using a 45 min accelerated low earth orbit (LEO) cycle regime at 80 percent depth of discharge. One of three cells containing 26 percent KOH has achieved over 28,000 cycles, and the other two 19,000 cycles, without a sign of failure. Two other cells containing 31 percent KOH electrolyte, which is the concentration presently used in aerospace cells, failed after 2,979 and 3,620 cycles. This result indicates that the cycle life of the present type of Ni/H2 cells may be extended by a factor of 5 to 10 simply by lowering the KOH concentration. Long cycle life of a Ni/H2 battery at high depth-of-discharge operation is desired, particularly for an LEO spacecraft application. Typically, battery life of about 30,000 cycles is required for a five year mission in an LEO. Such a cycle life with presently available cells can be assured only at a very low depth-of-discharge operation. Results of testing already show that the cycle life of an Ni/H2 cell is tremendously improved by simply using an electrolyte of low KOH concentration.

  10. Radiosensitization of C225 on human non-small cell lung cancer cell line H-520

    International Nuclear Information System (INIS)

    Zhang Yingdong; Wang Junjie; Liu Feng; Zhao Yong

    2008-01-01

    Objective: To investigate the efficacy of C225 (cetuximab), a chimeric human-mouse anti-epithelial growth factor receptor monoclonal antibody, combined with 60 Co gamma irradiation against human non-small cell lung cancer cell line H-520. Methods: H-520 cells were treated either with different dose of 60 Co irradiation (1,2,4,6,8 and 10 Gy)alone or together with C225 (100 nmol/L). Colony forming capacity was determined to create the survival curve 10 days after the treatment. Cells in different groups were harvested 72 hours after irradiation for apoptosis analysis or 48 hours after irradiation for cell cycle analysis by flow cytometry assay. Results: The clone number in combinational treatment group was less than that in irradiation only group, which suggested that the cell survival rate in the combinational treatment group was significantly decreased comparing with irradiation only group (F=6.36, P O + G 1 phases for C225 treatment, in G 2 + M phases for 60 Co irradiation, and in both G 0 + G 1 and G 2 + M phases for C225 in combination with 60 Co irradiation. Conclusions: C225 has radiosensitizing effects on H-520 cells, which may through the enhancement of 60 Co irradiation-induced cell death and cell cycle arrest. This study provides a supportive evidence for clinical treatment in non-small cell lung cancer. (authors)

  11. Molecular biological mechanism II. Molecular mechanisms of cell cycle regulation

    International Nuclear Information System (INIS)

    Jung, T.

    2000-01-01

    The cell cycle in eukaryotes is regulated by central cell cycle controlling protein kinase complexes. These protein kinase complexes consist of a catalytic subunit from the cyclin-dependent protein kinase family (CDK), and a regulatory subunit from the cyclin family. Cyclins are characterised by their periodic cell cycle related synthesis and destruction. Each cell cycle phase is characterised by a specific set of CDKs and cyclins. The activity of CDK/cyclin complexes is mainly regulated on four levels. It is controlled by specific phosphorylation steps, the synthesis and destruction of cyclins, the binding of specific inhibitor proteins, and by active control of their intracellular localisation. At several critical points within the cell cycle, named checkpoints, the integrity of the cellular genome is monitored. If damage to the genome or an unfinished prior cell cycle phase is detected, the cell cycle progression is stopped. These cell cycle blocks are of great importance to secure survival of cells. Their primary importance is to prevent the manifestation and heritable passage of a mutated genome to daughter cells. Damage sensing, DNA repair, cell cycle control and apoptosis are closely linked cellular defence mechanisms to secure genome integrity. Disregulation in one of these defence mechanisms are potentially correlated with an increased cancer risk and therefore in at least some cases with an increased radiation sensitivity. (orig.) [de

  12. Cellular radiosensitivity of small-cell lung cancer cell lines

    International Nuclear Information System (INIS)

    Krarup, Marianne; Poulsen, Hans Skovgaard; Spang-Thomsen, Mogens

    1997-01-01

    Purpose: The objective of this study was to determine the radiobiological characteristics of a panel of small-cell lung cancer (SCLC) cell lines by use of a clonogenic assay. In addition, we tested whether comparable results could be obtained by employing a growth extrapolation method based on the construction of continuous exponential growth curves. Methods and Materials: Fifteen SCLC cell lines were studied, applying a slightly modified clonogenic assay and a growth extrapolation method. A dose-survival curve was obtained for each experiment and used for calculating several survival parameters. The multitarget single hit model was applied to calculate the cellular radiosensitivity (D 0 ), the capacity for sublethal damage repair (D q ), and the extrapolation number (n). Values for α and β were determined from best-fit curves according to the linear-quadratic model and these values were applied to calculate the surviving fraction after 2-Gy irradiation (SF 2 ). Results: In our investigation, the extrapolation method proved to be inappropriate for the study of in vitro cellular radiosensitivity due to lack of reproducibility. The results obtained by the clonogenic assay showed that the cell lines studied were radiobiologically heterogeneous with no discrete features of the examined parameters including the repair capacity. Conclusion: The results indicate that SCLC tumors per se are not generally candidates for hyperfractionated radiotherapy

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

    Directory of Open Access Journals (Sweden)

    Gerhard Hamilton

    2014-03-01

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

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

    Science.gov (United States)

    Hamilton, Gerhard

    2014-01-01

    Fascaplysin, the natural product of a marine sponge, exhibits anticancer activity against a broad range of tumor cells, presumably through interaction with DNA, and/or as a highly selective cyclin-dependent kinase 4 (CDK4) inhibitor. In this study, cytotoxic activity of fascaplysin against a panel of small cell lung cancer (SCLC) cell lines and putative synergism with chemotherapeutics was investigated. SCLC responds to first-line chemotherapy with platinum-based drugs/etoposide, but relapses early with topotecan remaining as the single approved therapeutic agent. Fascaplysin was found to show high cytotoxicity against SCLC cells and to induce cell cycle arrest in G1/0 at lower and S-phase at higher concentrations, respectively. The compound generated reactive oxygen species (ROS) and induced apoptotic cell death in the chemoresistant NCI-H417 SCLC cell line. Furthermore, fascaplysin revealed marked synergism with the topoisomerase I-directed camptothecin and 10-hydroxy-camptothecin. The Poly(ADP-ribose)-Polymerase 1 (PARP1) inhibitor BYK 204165 antagonized the cytotoxic activity of fascaplysin, pointing to the involvement of DNA repair in response to the anticancer activity of the drug. In conclusion, fascaplysin seems to be suitable for treatment of SCLC, based on high cytotoxic activity through multiple routes of action, affecting topoisomerase I, integrity of DNA and generation of ROS. PMID:24608973

  15. Culture of human cell lines by a pathogen-inactivated human platelet lysate.

    Science.gov (United States)

    Fazzina, R; Iudicone, P; Mariotti, A; Fioravanti, D; Procoli, A; Cicchetti, E; Scambia, G; Bonanno, G; Pierelli, L

    2016-08-01

    Alternatives to the use of fetal bovine serum (FBS) have been investigated to ensure xeno-free growth condition. In this study we evaluated the efficacy of human platelet lysate (PL) as a substitute of FBS for the in vitro culture of some human cell lines. PL was obtained by pools of pathogen inactivated human donor platelet (PLT) concentrates. Human leukemia cell lines (KG-1, K562, JURKAT, HL-60) and epithelial tumor cell lines (HeLa and MCF-7) were cultured with either FBS or PL. Changes in cell proliferation, viability, morphology, surface markers and cell cycle were evaluated for each cell line. Functional characteristics were analysed by drug sensitivity test and cytotoxicity assay. Our results demonstrated that PL can support growth and expansion of all cell lines, although the cells cultured in presence of PL experienced a less massive proliferation compared to those grown with FBS. We found a comparable percentage of viable specific marker-expressing cells in both conditions, confirming lineage fidelity in all cultures. Functionality assays showed that cells in both FBS- and PL-supported cultures maintained their normal responsiveness to adriamycin and NK cell-mediated lysis. Our findings indicate that PL is a feasible serum substitute for supporting growth and propagation of haematopoietic and epithelial cell lines with many advantages from a perspective of process standardization, ethicality and product safety.

  16. Susceptibility testing of fish cell lines for virus isolation

    DEFF Research Database (Denmark)

    Ariel, Ellen; Skall, Helle Frank; Olesen, Niels Jørgen

    2009-01-01

    and laboratories, but also between lineages of the same cell line. To minimise the occurrence of false negatives in a cell culture based surveillance system, we have investigated methods, to select cell lineages that are relatively superior in their susceptibility to a panel of virus isolates. The procedures...... cell lineages, we increased the number of isolates of each virus, propagated stocks in a given cell line and tested all lineages of that line in use in the laboratory. Testing of relative cell line susceptibility between laboratories is carried out annually via the Inter-laboratory Proficiency Test...... sensitivity for surveillance purposes within a cell line and between laboratories.In terms of economic and practical considerations as well as attempting to approach a realistic test system, we suggest the optimal procedure for susceptibility testing of fish cell lines for virus isolation to be a combination...

  17. Cell cycle control by the thyroid hormone in neuroblastoma cells

    International Nuclear Information System (INIS)

    Garcia-Silva, Susana; Perez-Juste, German; Aranda, Ana

    2002-01-01

    The thyroid hormone (T3) blocks proliferation and induces differentiation of neuroblastoma N2a-β cells that overexpress the β1 isoform of the T3 receptor. An element in the region responsible for premature termination of transcription mediates a rapid repression of c-myc gene expression by T3. The hormone also causes a decrease of cyclin D1 gene transcription, and is able to antagonize the activation of the cyclin D1 promoter by Ras. In addition, a strong and sustained increase of the levels of the cyclin kinase inhibitor (CKI) p27 Kip1 are found in T3-treated cells. The increased levels of p27 Kip1 lead to a marked inhibition of the kinase activity of the cyclin-CDK2 complexes. As a consequence of these changes, retinoblastoma proteins are hypophosphorylated in T3-treated N2a-β cells, and progression through the restriction point in the cell cycle is blocked

  18. Cell cycle checkpoints: reversible when possible, irreversible when needed

    NARCIS (Netherlands)

    Krenning, L.

    2015-01-01

    Cell cycle checkpoints are reversible in nature, and can prevent progression into the next cell cycle phase if needed. In the case of DNA damage, cells can prevent progression from G1 into S phase, and from G2 into mitosis in the presence of DNA double strand breaks. Following DNA repair, these

  19. Arctigenin induces cell cycle arrest by blocking the phosphorylation of Rb via the modulation of cell cycle regulatory proteins in human gastric cancer cells.

    Science.gov (United States)

    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. Crown Copyright © 2011. Published by Elsevier B.V. All rights reserved.

  20. Cell cycle controls: potential targets for chemical carcinogens?

    OpenAIRE

    Afshari, C A; Barrett, J C

    1993-01-01

    The progression of the cell cycle is controlled by the action of both positive and negative growth regulators. The key players in this activity include a family of cyclins and cyclin-dependent kinases, which are themselves regulated by other kinases and phosphatases. Maintenance of balanced cell cycle controls may be directly linked to genomic stability. Loss of the check-points involved in cell cycle control may result in unrepaired DNA damage during DNA synthesis or mitosis leading to genet...

  1. The role of autophagy inhibition in the enhanced cytotoxicity of temozolomide on melanoma cell lines

    Directory of Open Access Journals (Sweden)

    O. O. Ryabaya

    2017-01-01

    Full Text Available Background. Despite advantages in treatment of metastatic melanoma it remains resistant to current therapy. Recent evidence indicates that tumor cells could overcome death through autophagy, a process that degrades cellular proteins and organelles to maintain cellular biosynthesis during nutrient deprivation or lack of energy. Objective: to investigate the involvement of autophagy inhibitors chloroquine (CQ and LY-294.002 (LY in temozolomide (TMZ cytotoxicity in human melanoma cell lines.Materials and methods. The study was performed on patient-derived melanoma cell lines Mel Z, Mel IL and Mel MTP. The antiproliferative activity of combined TMZ and autophagy inhibitors treatment was determined by MTT assay and colony-forming assay. Cell cycle analysis, apoptosis activation and expression analysis of key autophagy markers under combined treatment was evaluated.Results. CQ and LY enhanced the cytotoxicity of TMZ and reduced colony formation in 3 melanoma cell lines, moreover both inhibitors increased cell population in G0 / G1 phase of cell cycle in Mel Z, Mel IL cell lines, but not in Mel MTP. CQ and LY synergistically activated apoptosis in all cell lines. The matrix RNA expression analysis of key autophagy genes showed autophagy involvement in enhanced cytotoxicity.Conclusions. Thus, autophagy inhibition on different stages of this process could overcome resistance to TMZ and be applicable as potent target in metastatic melanoma treatment.

  2. Protein kinase C signaling and cell cycle regulation

    OpenAIRE

    Black, Adrian R.; Black, Jennifer D.

    2013-01-01

    A link between T cell proliferation and the protein kinase C (PKC) family of serine/threonine kinases has been recognized for about thirty years. However, despite the wealth of information on PKC-mediated control of T cell activation, understanding of the effects of PKCs on the cell cycle machinery in this cell type remains limited. Studies in other systems have revealed important cell cycle-specific effects of PKC signaling that can either positively or negatively impact proliferation. Th...

  3. Characterization of a Merkel Cell Polyomavirus-Positive Merkel Cell Carcinoma Cell Line CVG-1.

    Science.gov (United States)

    Velásquez, Celestino; Amako, Yutaka; Harold, Alexis; Toptan, Tuna; Chang, Yuan; Shuda, Masahiro

    2018-01-01

    Merkel cell polyomavirus (MCV) plays a causal role in ∼80% of Merkel cell carcinomas (MCC). MCV is clonally integrated into the MCC tumor genome, which results in persistent expression of large T (LT) and small T (sT) antigen oncoproteins encoded by the early locus. In MCV-positive MCC tumors, LT is truncated by premature stop codons or deletions that lead to loss of the C-terminal origin binding (OBD) and helicase domains important for replication. The N-terminal Rb binding domain remains intact. MCV-positive cell lines derived from MCC explants have been valuable tools to study the molecular mechanism of MCV-induced Merkel cell carcinogenesis. Although all cell lines have integrated MCV and express truncated LT antigens, the molecular sizes of the LT proteins differ between cell lines. The copy number of integrated viral genome also varies across cell lines, leading to significantly different levels of viral protein expression. Nevertheless, these cell lines share phenotypic similarities in cell morphology, growth characteristics, and neuroendocrine marker expression. Several low-passage MCV-positive MCC cell lines have been established since the identification of MCV. We describe a new MCV-positive MCV cell line, CVG-1, with features distinct from previously reported cell lines. CVG-1 tumor cells grow in more discohesive clusters in loose round cell suspension, and individual cells show dramatic size heterogeneity. It is the first cell line to encode an MCV sT polymorphism resulting in a unique leucine (L) to proline (P) substitution mutation at amino acid 144. CVG-1 possesses a LT truncation pattern near identical to that of MKL-1 cells differing by the last two C-terminal amino acids and also shows an LT protein expression level similar to MKL-1. Viral T antigen knockdown reveals that, like other MCV-positive MCC cell lines, CVG-1 requires T antigen expression for cell proliferation.

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

    Science.gov (United States)

    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

  5. Cyclin D1 overexpression, cell cycle progression and radiosensitivity in MBP cells

    International Nuclear Information System (INIS)

    Wu Lijun; Yu Zengliang

    2000-11-01

    Clones that exhibited a minimum of 7-8 fold cyclin D1 level above the parent cell lines or the vector control were obtained after transfected with the entire coding sequence of human 1.1 kb cyclin D1 cDNA. Studies showed that there was no significant difference in Radiosensitivity between over-expressing cyclin D1 and control cultures from either mouse or human origin. Using flow cytometry to access cell cycle distribution in the exponentially growth cultures of MCF10F-D1-21 and MCF10F-V-3, it was found that there was a 50 percent increase in the proportion of G2/M phase cells and 5.3 percent decrease in the proportion of G0/G1 phase cells in MCF10F-D1-21 comparing with MCF10F-V-3, though they were with the same proportion of cells in S phase

  6. Preparing nuclei from cells in monolayer cultures suitable for counting and for following synchronized cells through the cell cycle.

    Science.gov (United States)

    Butler, W B

    1984-08-15

    A procedure is described for preparing nuclei from cells in monolayer culture so that they may be counted using an electronic particle counter. It takes only 10 to 15 min, and consists of swelling the cells in hypotonic buffer and then lysing them with the quaternary ammonium salt, ethylhexadecyldimethylammonium bromide. The cells are completely lysed, yielding a suspension of clean single nuclei which is stable, free of debris, and easily counted. The method was developed for a cell line of epithelial origin (MCF-7), which is often difficult to trypsinize to single cells. It works equally well at all cell densities up to and beyond confluence, and has been used with a variety of cells in culture, including 3T3 cells, bovine macrophages, rat mammary epithelial cells, mouse mammary tumor cell lines, and human fibroblasts. The size of the nuclei produced by this procedure is related to their DNA content, and the method is thus suitable for following cultures of synchronized cells through the cell cycle, and for performing differential counts of cells with substantial differences in DNA content.

  7. Radiation response of mouse lymphoid and myeloid cell lines. Pt. 3

    International Nuclear Information System (INIS)

    Radford, I.R.; Murphy, T.K.

    1994-01-01

    The authors have examined the timing of γ-irradiation-induced death in relation to cell cycle progression using a panel of mouse lymphoid or myeloid cell lines. Death was found to occur immediately after irradiation ('rapid interphase' death), or after arrest in G 2 phase ('delayed interphase' death), or following one or more mitoses ('mitotic/delayed mitotic' death). In part II of this series of papers the authors demonstrated the occurrence of radiation-induced apoptosis in all these cell lines. Several of the cell lines showed different timing of death dependent upon the radiation dose used. These differences in the timing of radiation-induced death are shown to be useful indicators of the relative radiosensitivity of haematopoietic cell lines. (author)

  8. Temporal fluxomics reveals oscillations in TCA cycle flux throughout the mammalian cell cycle.

    Science.gov (United States)

    Ahn, Eunyong; Kumar, Praveen; Mukha, Dzmitry; Tzur, Amit; Shlomi, Tomer

    2017-11-06

    Cellular metabolic demands change throughout the cell cycle. Nevertheless, a characterization of how metabolic fluxes adapt to the changing demands throughout the cell cycle is lacking. Here, we developed a temporal-fluxomics approach to derive a comprehensive and quantitative view of alterations in metabolic fluxes throughout the mammalian cell cycle. This is achieved by combining pulse-chase LC-MS-based isotope tracing in synchronized cell populations with computational deconvolution and metabolic flux modeling. We find that TCA cycle fluxes are rewired as cells progress through the cell cycle with complementary oscillations of glucose versus glutamine-derived fluxes: Oxidation of glucose-derived flux peaks in late G1 phase, while oxidative and reductive glutamine metabolism dominates S phase. These complementary flux oscillations maintain a constant production rate of reducing equivalents and oxidative phosphorylation flux throughout the cell cycle. The shift from glucose to glutamine oxidation in S phase plays an important role in cell cycle progression and cell proliferation. © 2017 The Authors. Published under the terms of the CC BY 4.0 license.

  9. Tofacitinib induces G1 cell-cycle arrest and inhibits tumor growth in Epstein-Barr virus-associated T and natural killer cell lymphoma cells.

    Science.gov (United States)

    Ando, Shotaro; Kawada, Jun-Ichi; Watanabe, Takahiro; Suzuki, Michio; Sato, Yoshitaka; Torii, Yuka; Asai, Masato; Goshima, Fumi; Murata, Takayuki; Shimizu, Norio; Ito, Yoshinori; Kimura, Hiroshi

    2016-11-22

    Epstein-Barr virus (EBV) infects not only B cells, but also T cells and natural killer (NK) cells, and is associated with T or NK cell lymphoma. These lymphoid malignancies are refractory to conventional chemotherapy. We examined the activation of the JAK3/STAT5 pathway in EBV-positive and -negative B, T and NK cell lines and in cell samples from patients with EBV-associated T cell lymphoma. We then evaluated the antitumor effects of the selective JAK3 inhibitor, tofacitinib, against these cell lines in vitro and in a murine xenograft model. We found that all EBV-positive T and NK cell lines and patient samples tested displayed activation of the JAK3/STAT5 pathway. Treatment of these cell lines with tofacitinib reduced the levels of phospho-STAT5, suppressed proliferation, induced G1 cell-cycle arrest and decreased EBV LMP1 and EBNA1 expression. An EBV-negative NK cell line was also sensitive to tofacitinib, whereas an EBV-infected NK cell line was more sensitive to tofacitinib than its parental line. Tofacitinib significantly inhibited the growth of established tumors in NOG mice. These findings suggest that tofacitinib may represent a useful therapeutic agent for patients with EBV-associated T and NK cell lymphoma.

  10. MODERATE CYTOTOXICITY OF PROANTHOCYANIDINS TO HUMAN TUMOR-CELL LINES

    NARCIS (Netherlands)

    KOLODZIEJ, H; HABERLAND, C; WOERDENBAG, HJ; KONINGS, AWT

    In the present study the cytotoxicity of 16 proanthocyanidins was evaluated in GLC(4), a human small cell lung carcinoma cell line, and in COLO 320, a human colorectal cancer cell line, using the microculture tetrazolium (MTT) assay. With IC50 values ranging from 18 to >200 mu m following continuous

  11. A Method to Design Synthetic Cell-Cycle Networks

    International Nuclear Information System (INIS)

    Ke-Ke, Miao

    2009-01-01

    The interactions among proteins, DNA and RNA in an organism form elaborate cell-cycle networks which govern cell growth and proliferation. Understanding the common structure of cell-cycle networks will be of great benefit to science research. Here, inspired by the importance of the cell-cycle regulatory network of yeast which has been studied intensively, we focus on small networks with 11 nodes, equivalent to that of the cell-cycle regulatory network used by Li et al. [Proc. Natl. Acad. Sci. USA 101(2004)4781] Using a Boolean model, we study the correlation between structure and function, and a possible common structure. It is found that cascade-like networks with a great number of interactions between nodes are stable. Based on these findings, we are able to construct synthetic networks that have the same functions as the cell-cycle regulatory network. (condensed matter: structure, mechanical and thermal properties)

  12. Playing with the cell cycle to build the spinal cord.

    Science.gov (United States)

    Molina, Angie; Pituello, Fabienne

    2017-12-01

    A fundamental issue in nervous system development and homeostasis is to understand the mechanisms governing the balance between the maintenance of proliferating progenitors versus their differentiation into post-mitotic neurons. Accumulating data suggest that the cell cycle and core regulators of the cell cycle machinery play a major role in regulating this fine balance. Here, we focus on the interplay between the cell cycle and cellular and molecular events governing spinal cord development. We describe the existing links between the cell cycle and interkinetic nuclear migration (INM). We show how the different morphogens patterning the neural tube also regulate the cell cycle machinery to coordinate proliferation and patterning. We give examples of how cell cycle core regulators regulate transcriptionally, or post-transcriptionally, genes involved in controlling the maintenance versus the differentiation of neural progenitors. Finally, we describe the changes in cell cycle kinetics occurring during neural tube patterning and at the time of neuronal differentiation, and we discuss future research directions to better understand the role of the cell cycle in cell fate decisions. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Metabolic characterization of invaded cells of the pancreatic cancer cell line, PANC-1.

    Science.gov (United States)

    Fujita, Mayumi; Imadome, Kaori; Imai, Takashi

    2017-05-01

    We previously reported that about 0.4% of cells in the cultured human pancreatic cancer cell line, PANC-1, can invade matrigel during the transwell invasion assay, suggesting that these invaded PANC-1 cells may have specific characteristics to keep their invasive potential. To identify the metabolic characterization specific in the invaded PANC-1 cells, metabolome analysis of the invaded PANC-1 compared with the whole cultured PANC-1 was performed using CE-TOFMS, and concentrations of 110 metabolites were measured. In contrast to the whole cultured cells, the invaded PANC-1 was characterized as a population with reduced levels of amino acids and TCA cycle intermediates, and decreased and increased intermediates in glycolysis and nucleic acid metabolism. In particular, the ratio of both adenosine and guanosine energy charge was reduced in the invaded cells, revealing that the consumption of ATP and GTP was high in the invaded cells, and thus suggesting that ATP- or GTP-generating pathways are stimulated. In addition, the GSH/GSSG ratio was low in the invaded cells, but these cells had a higher surviving fraction after exposure to hydrogen peroxide. Thus, the invaded cells were the population resistant to oxidative stress. Furthermore, reduction in intracellular GSH content inhibited PANC-1 invasiveness, indicated that GSH has an important role in PANC-1 invasiveness. Overall, we propose the invaded cells have several unique metabolic profiles. © 2017 The Authors. Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association.

  14. Investigation of the selenium metabolism in cancer cell lines

    DEFF Research Database (Denmark)

    Lunøe, Kristoffer; Gabel-Jensen, Charlotte; Stürup, Stefan

    2011-01-01

    The aim of this work was to compare different selenium species for their ability to induce cell death in different cancer cell lines, while investigating the underlying chemistry by speciation analysis. A prostate cancer cell line (PC-3), a colon cancer cell line (HT-29) and a leukaemia cell line...... (Jurkat E6-1) were incubated with five selenium compounds representing inorganic as well as organic Se compounds in different oxidation states. Selenomethionine (SeMet), Se-methylselenocysteine (MeSeCys), methylseleninic acid (MeSeA), selenite and selenate in the concentration range 5-100 mu M were...... incubated with cells for 24 h and the induction of cell death was measured using flow cytometry. The amounts of total selenium in cell medium, cell lysate and the insoluble fractions was determined by ICP-MS. Speciation analysis of cellular fractions was performed by reversed phase, anion exchange and size...

  15. Cell-cycle-dependent regulation of cell motility and determination of the role of Rac1

    DEFF Research Database (Denmark)

    Walmod, Peter S.; Hartmann-Petersen, Rasmus; Prag, S.

    2004-01-01

    comparable to those of control cells in G1. In contrast, transfection with dominant-negative Rac1 reduced cell speed and resulted in cellular displacements, which were identical in G1 and G2. These observations indicate that migration of cultured cells is regulated in a cell-cycle-dependent manner...... for calculation of three key parameters describing cell motility: speed, persistence time and rate of diffusion. All investigated cell lines demonstrated a lower cell displacement in the G2 phase than in the G1/S phases. This was caused by a decrease in speed and/or persistence time. The decrease in motility...... was accompanied by changes in morphology reflecting the larger volume of cells in G2 than in G1. Furthermore, L-cells and HeLa-cells appeared to be less adherent in the G2 phase. Transfection of L-cells with constitutively active Rac1 led to a general increase in the speed and rate of diffusion in G2 to levels...

  16. Derivation and characterization of a pig embryonic stem cell-derived exocrine pancreatic cell line

    Science.gov (United States)

    The establishment and initial characterization of a pig embryonic stem cell-derived pancreatic cell line, PICM-31, and a colony-cloned derivative cell line, PICM-31A, is described. The cell lines were propagated for several months at split ratios of 1:3 or 1:5 at each passage on STO feeder cells af...

  17. Variety in intracellular diffusion during the cell cycle

    DEFF Research Database (Denmark)

    Selhuber-Unkel, C.; Yde, P.; Berg-Sørensen, Kirstine

    2009-01-01

    During the cell cycle, the organization of the cytoskeletal network undergoes dramatic changes. In order to reveal possible changes of the viscoelastic properties in the intracellular space during the cell cycle we investigated the diffusion of endogenous lipid granules within the fission yeast...... Schizosaccharomyces Pombe using optical tweezers. The cell cycle was divided into interphase and mitotic cell division, and the mitotic cell division was further subdivided in its stages. During all stages of the cell cycle, the granules predominantly underwent subdiffusive motion, characterized by an exponent...... a that is also linked to the viscoelastic moduli of the cytoplasm. The exponent a was significantly smaller during interphase than during any stage of the mitotic cell division, signifying that the cytoplasm was more elastic during interphase than during division. We found no significant differences...

  18. Rethinking cell-cycle-dependent gene expression in Schizosaccharomyces pombe.

    Science.gov (United States)

    Cooper, Stephen

    2017-11-01

    Three studies of gene expression during the division cycle of Schizosaccharomyces pombe led to the proposal that a large number of genes are expressed at particular times during the S. pombe cell cycle. Yet only a small fraction of genes proposed to be expressed in a cell-cycle-dependent manner are reproducible in all three published studies. In addition to reproducibility problems, questions about expression amplitudes, cell-cycle timing of expression, synchronization artifacts, and the problem with methods for synchronizing cells must be considered. These problems and complications prompt the idea that caution should be used before accepting the conclusion that there are a large number of genes expressed in a cell-cycle-dependent manner in S. pombe.

  19. Targeting ceramide metabolic pathway induces apoptosis in human breast cancer cell lines

    Energy Technology Data Exchange (ETDEWEB)

    Vethakanraj, Helen Shiphrah; Babu, Thabraz Ahmed; Sudarsanan, Ganesh Babu; Duraisamy, Prabhu Kumar; Ashok Kumar, Sekar, E-mail: sekarashok@gmail.com

    2015-08-28

    The sphingolipid ceramide is a pro apoptotic molecule of ceramide metabolic pathway and is hydrolyzed to proliferative metabolite, sphingosine 1 phosphate by the action of acid ceramidase. Being upregulated in the tumors of breast, acid ceramidase acts as a potential target for breast cancer therapy. We aimed at targeting this enzyme with a small molecule acid ceramidase inhibitor, Ceranib 2 in human breast cancer cell lines MCF 7 and MDA MB 231. Ceranib 2 effectively inhibited the growth of both the cell lines in dose and time dependant manner. Morphological apoptotic hallmarks such as chromatin condensation, fragmented chromatin were observed in AO/EtBr staining. Moreover, ladder pattern of fragmented DNA observed in DNA gel electrophoresis proved the apoptotic activity of Ceranib 2 in breast cancer cell lines. The apoptotic events were associated with significant increase in the expression of pro-apoptotic genes (Bad, Bax and Bid) and down regulation of anti-apoptotic gene (Bcl 2). Interestingly, increase in sub G1 population of cell cycle phase analysis and elevated Annexin V positive cells after Ceranib 2 treatment substantiated its apoptotic activity in MCF 7 and MDA MB 231 cell lines. Thus, we report Ceranib 2 as a potent therapeutic agent against both ER{sup +} and ER{sup −} breast cancer cell lines. - Highlights: • Acid Ceramidase inhibitor, Ceranib 2 induced apoptosis in Breast cancer cell lines (MCF 7 and MDA MB 231 cell lines). • Apoptosis is mediated by DNA fragmentation and cell cycle arrest. • Ceranib 2 upregulated the expression of pro-apoptotic genes and down regulated anti-apoptotic gene expression. • More potent compared to the standard drug Tamoxifen.

  20. Targeting ceramide metabolic pathway induces apoptosis in human breast cancer cell lines

    International Nuclear Information System (INIS)

    Vethakanraj, Helen Shiphrah; Babu, Thabraz Ahmed; Sudarsanan, Ganesh Babu; Duraisamy, Prabhu Kumar; Ashok Kumar, Sekar

    2015-01-01

    The sphingolipid ceramide is a pro apoptotic molecule of ceramide metabolic pathway and is hydrolyzed to proliferative metabolite, sphingosine 1 phosphate by the action of acid ceramidase. Being upregulated in the tumors of breast, acid ceramidase acts as a potential target for breast cancer therapy. We aimed at targeting this enzyme with a small molecule acid ceramidase inhibitor, Ceranib 2 in human breast cancer cell lines MCF 7 and MDA MB 231. Ceranib 2 effectively inhibited the growth of both the cell lines in dose and time dependant manner. Morphological apoptotic hallmarks such as chromatin condensation, fragmented chromatin were observed in AO/EtBr staining. Moreover, ladder pattern of fragmented DNA observed in DNA gel electrophoresis proved the apoptotic activity of Ceranib 2 in breast cancer cell lines. The apoptotic events were associated with significant increase in the expression of pro-apoptotic genes (Bad, Bax and Bid) and down regulation of anti-apoptotic gene (Bcl 2). Interestingly, increase in sub G1 population of cell cycle phase analysis and elevated Annexin V positive cells after Ceranib 2 treatment substantiated its apoptotic activity in MCF 7 and MDA MB 231 cell lines. Thus, we report Ceranib 2 as a potent therapeutic agent against both ER + and ER − breast cancer cell lines. - Highlights: • Acid Ceramidase inhibitor, Ceranib 2 induced apoptosis in Breast cancer cell lines (MCF 7 and MDA MB 231 cell lines). • Apoptosis is mediated by DNA fragmentation and cell cycle arrest. • Ceranib 2 upregulated the expression of pro-apoptotic genes and down regulated anti-apoptotic gene expression. • More potent compared to the standard drug Tamoxifen

  1. A Vitex agnus-castus extract inhibits cell growth and induces apoptosis in prostate epithelial cell lines.

    Science.gov (United States)

    Weisskopf, M; Schaffner, W; Jundt, G; Sulser, T; Wyler, S; Tullberg-Reinert, H

    2005-10-01

    Extracts of Vitex agnus-castus fruits (VACF) are described to have beneficial effects on disorders related to hyperprolactinemia (cycle disorders, premenstrual syndrome). A VACF extract has recently been shown to exhibit antitumor activities in different human cancer cell lines. In the present study, we explored the antiproliferative effects of a VACF extract with a particular focus on apoptosis-inducing and potential cytotoxic effects. Three different human prostate epithelial cell lines (BPH-1, LNCaP, PC-3) representing different disease stages and androgen responsiveness were chosen. The action of VACF on cell viability was assessed using the WST-8-tetrazolium assay. Cell proliferation in cells receiving VACF alone or in combination with a pan-caspase inhibitor (Z-VAD-fmk) was quantified using a Crystal Violet assay. Flow cytometric cell cycle analysis and measurement of DNA fragmentation using an ELISA method were used for studying the induction of apoptosis. Lactate dehydrogenase (LDH) activity was determined as a marker of cytotoxicity. The extract inhibited proliferation of all three cell lines in a concentration-dependent manner with IC (50) values below 10 microg/mL after treatment for 48 h. Cell cycle analysis and DNA fragmentation assays suggest that part of the cells were undergoing apoptosis. The VACF-induced decrease in cell number was partially inhibited by Z-VAD-fmk, indicating a caspase-dependent apoptotic cell death. However, the concentration-dependent LDH activity of VACF treated cells indicated cytotoxic effects as well. These data suggest that VACF contains components that inhibit proliferation and induce apoptosis in human prostate epithelial cell lines. The extract may be useful for the prevention and/or treatment not only of benign prostatic hyperplasia but also of human prostate cancer.

  2. Chromatin association of UHRF1 during the cell cycle

    KAUST Repository

    Al-Gashgari, Bothayna

    2017-05-01

    Ubiquitin-like with PHD and RING Finger domains 1 (UHRF1) is a nuclear protein that associates with chromatin. Regardless of the various functions of UHRF1 in the cell, one of its more important functions is its role in the maintenance of DNA methylation patterns by the recruitment of DNMT1. Studies on UHRF1 based on this function have revealed the importance of UHRF1 during the cell cycle. Moreover, based on different studies various factors were described to be involved in the regulation of UHRF1 with different functionalities that can control its binding affinity to different targets on chromatin. These factors are regulated differently in a cell cycle specific manner. In light of this, we propose that UHRF1 has different binding behaviors during the cell cycle in regard to its association with chromatin. In this project, we first analyzed the binding behavior of endogenous UHRF1 from different unsynchronized cell systems in pull-down assays with peptides and oligonucleotides. Moreover, to analyze UHRF1 binding behavior during the cell cycle, we used two different approaches. First we sorted Jurkat and HT1080 cells based on their cell cycle stage using FACS analysis. Additionally, we synchronized HeLa cells to different stages of the cell cycle by chemical treatments, and used extracts from cellsorting and cell synchronization experiments for pull-down assays. We observed that UHRF1 in different cell systems has different preferences in regard to its binding to H3 unmodified and H3K9me3. Moreover, we detected that UHRF1, in general, displays different patterns between different stages of cell cycle; however, we cannot draw a final model for UHRF1 binding pattern during cell cycle.

  3. Mechanisms involved in alternariol-induced cell cycle arrest

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-10-15

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

  4. Mechanisms involved in alternariol-induced cell cycle arrest

    International Nuclear Information System (INIS)

    Solhaug, A.; Vines, L.L.; Ivanova, L.; Spilsberg, B.; Holme, J.A.; Pestka, J.; Collins, A.; Eriksen, G.S.

    2012-01-01

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

  5. Feeder-cell-independent culture of the pig-embryonic-stem-cell-derived exocrine pancreatic cell line, PICM-31

    Science.gov (United States)

    The adaptation to feeder-independent growth of a pig embryonic stem cell-derived pancreatic cell line is described. The parental PICM-31 cell line, previously characterized as an exocrine pancreas cell line, was colony-cloned two times in succession resulting in the subclonal cell line, PICM-31A1. P...

  6. RPS27a promotes proliferation, regulates cell cycle progression and inhibits apoptosis of leukemia cells

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Houcai; Yu, Jing; Zhang, Lixia; Xiong, Yuanyuan; Chen, Shuying; Xing, Haiyan; Tian, Zheng; Tang, Kejing; Wei, Hui; Rao, Qing; Wang, Min; Wang, Jianxiang, E-mail: wangjx@ihcams.ac.cn

    2014-04-18

    Highlights: • RPS27a expression was up-regulated in advanced-phase CML and AL patients. • RPS27a knockdown changed biological property of K562 and K562/G01 cells. • RPS27a knockdown affected Raf/MEK/ERK, P21 and BCL-2 signaling pathways. • RPS27a knockdown may be applicable for new combination therapy in CML patients. - Abstract: Ribosomal protein S27a (RPS27a) could perform extra-ribosomal functions besides imparting a role in ribosome biogenesis and post-translational modifications of proteins. The high expression level of RPS27a was reported in solid tumors, and we found that the expression level of RPS27a was up-regulated in advanced-phase chronic myeloid leukemia (CML) and acute leukemia (AL) patients. In this study, we explored the function of RPS27a in leukemia cells by using CML cell line K562 cells and its imatinib resistant cell line K562/G01 cells. It was observed that the expression level of RPS27a was high in K562 cells and even higher in K562/G01 cells. Further analysis revealed that RPS27a knockdown by shRNA in both K562 and K562G01 cells inhibited the cell viability, induced cell cycle arrest at S and G2/M phases and increased cell apoptosis induced by imatinib. Combination of shRNA with imatinib treatment could lead to more cleaved PARP and cleaved caspase-3 expression in RPS27a knockdown cells. Further, it was found that phospho-ERK(p-ERK) and BCL-2 were down-regulated and P21 up-regulated in RPS27a knockdown cells. In conclusion, RPS27a promotes proliferation, regulates cell cycle progression and inhibits apoptosis of leukemia cells. It appears that drugs targeting RPS27a combining with tyrosine kinase inhibitor (TKI) might represent a novel therapy strategy in TKI resistant CML patients.

  7. Cell Cycle Related Differentiation of Bone Marrow Cells into Lung Cells

    Energy Technology Data Exchange (ETDEWEB)

    Dooner, Mark; Aliotta, Jason M.; Pimental, Jeffrey; Dooner, Gerri J.; Abedi, Mehrdad; Colvin, Gerald; Liu, Qin; Weier, Heinz-Ulli; Dooner, Mark S.; Quesenberry, Peter J.

    2007-12-31

    Green-fluorescent protein (GFP) labeled marrow cells transplanted into lethally irradiated mice can be detected in the lungs of transplanted mice and have been shown to express lung specific proteins while lacking the expression of hematopoietic markers. We have studied marrow cells induced to transit cell cycle by exposure to IL-3, IL-6, IL-11 and steel factor at different times of culture corresponding to different phases of cell cycle. We have found that marrow cells at the G1/S interface have a 3-fold increase in cells which assume a lung phenotype and that this increase is no longer seen in late S/G2. These cells have been characterized as GFP{sup +} CD45{sup -} and GFP{sup +} cytokeratin{sup +}. Thus marrow cells with the capacity to convert into cells with a lung phenotype after transplantation show a reversible increase with cytokine induced cell cycle transit. Previous studies have shown the phenotype of bone marrow stem cells fluctuates reversibly as these cells traverse cell cycle, leading to a continuum model of stem cell regulation. The present studies indicate that marrow stem cell production of nonhematopoietic cells also fluctuates on a continuum.

  8. Connecting the nucleolus to the cell cycle and human disease.

    Science.gov (United States)

    Tsai, Robert Y L; Pederson, Thoru

    2014-08-01

    Long known as the center of ribosome synthesis, the nucleolus is connected to cell cycle regulation in more subtle ways. One is a surveillance system that reacts promptly when rRNA synthesis or processing is impaired, halting cell cycle progression. Conversely, the nucleolus also acts as a first-responder to growth-related stress signals. Here we review emerging concepts on how these "infraribosomal" links between the nucleolus and cell cycle progression operate in both forward and reverse gears. We offer perspectives on how new cancer therapeutic designs that target this infraribosomal mode of cell growth control may shape future clinical progress. © FASEB.

  9. Peroxisomal abnormalities in the immortalized human hepatocyte (IHH) cell line.

    Science.gov (United States)

    Klouwer, Femke C C; Koster, Janet; Ferdinandusse, Sacha; Waterham, Hans R

    2017-04-01

    The immortalized human hepatocyte (IHH) cell line is increasingly used for studies related to liver metabolism, including hepatic glucose, lipid, lipoprotein and triglyceride metabolism, and the effect of therapeutic interventions. To determine whether the IHH cell line is a good model to investigate hepatic peroxisomal metabolism, we measured several peroxisomal parameters in IHH cells and, for comparison, HepG2 cells and primary skin fibroblasts. This revealed a marked plasmalogen deficiency and a deficient fatty acid α-oxidation in the IHH cells, due to a defect of PEX7, a cytosolic receptor protein required for peroxisomal import of a subset of peroxisomal proteins. These abnormalities have consequences for the lipid homeostasis of these cells and thus should be taken into account for the interpretation of data previously generated by using this cell line and when considering using this cell line for future research.

  10. Radiation response of haematopoietic cell lines of human origin

    International Nuclear Information System (INIS)

    Lehnert, S.; Rybka, W.B.; Suissa, S.; Giambattisto, D.

    1986-01-01

    Six human haematopoietic cell lines, five of leukaemic origin, including cells with myeloid, lymphoid and undifferentiated phenotype have been studied with respect to radiation response. The intrinsic radio-sensitivity of the cells varied widely, the D 0 s ranging from 0.53 to 1.39 Gy. Five of the cell lines showed some capacity to accumulate sublethal damage; in three of these, enhanced survival was demonstrated in split-dose experiments. One cell line (HL-60) was anomalous in that although little accumulation of sublethal damage was demonstrable, survival was enhanced by fractionation of the dose. Five of the six cell lines studied were of leukaemic origin. The results support the belief that, in contrast to the almost constant radiosensitivity of normal haematopoietic cell progenitors, leukaemic cell progenitors may show a wide range of radiosensitivities. (author)

  11. Repressive histone methylation regulates cardiac myocyte cell cycle exit.

    Science.gov (United States)

    El-Nachef, Danny; Oyama, Kyohei; Wu, Yun-Yu; Freeman, Miles; Zhang, Yiqiang; Robb MacLellan, W

    2018-05-22

    Mammalian cardiac myocytes (CMs) stop proliferating soon after birth and subsequent heart growth comes from hypertrophy, limiting the adult heart's regenerative potential after injury. The molecular events that mediate CM cell cycle exit are poorly understood. To determine the epigenetic mechanisms limiting CM cycling in adult CMs (ACMs) and whether trimethylation of lysine 9 of histone H3 (H3K9me3), a histone modification associated with repressed chromatin, is required for the silencing of cell cycle genes, we developed a transgenic mouse model where H3K9me3 is specifically removed in CMs by overexpression of histone demethylase, KDM4D. Although H3K9me3 is found across the genome, its loss in CMs preferentially disrupts cell cycle gene silencing. KDM4D binds directly to cell cycle genes and reduces H3K9me3 levels at these promotors. Loss of H3K9me3 preferentially leads to increased cell cycle gene expression resulting in enhanced CM cycling. Heart mass was increased in KDM4D overexpressing mice by postnatal day 14 (P14) and continued to increase until 9-weeks of age. ACM number, but not size, was significantly increased in KDM4D expressing hearts, suggesting CM hyperplasia accounts for the increased heart mass. Inducing KDM4D after normal development specifically in ACMs resulted in increased cell cycle gene expression and cycling. We demonstrated that H3K9me3 is required for CM cell cycle exit and terminal differentiation in ACMs. Depletion of H3K9me3 in adult hearts prevents and reverses permanent cell cycle exit and allows hyperplastic growth in adult hearts in vivo. Copyright © 2017. Published by Elsevier Ltd.

  12. Estrogen receptor alpha is cell cycle-regulated and regulates the cell cycle in a ligand-dependent fashion.

    Science.gov (United States)

    JavanMoghadam, Sonia; Weihua, Zhang; Hunt, Kelly K; Keyomarsi, Khandan

    2016-06-17

    Estrogen receptor alpha (ERα) has been implicated in several cell cycle regulatory events and is an important predictive marker of disease outcome in breast cancer patients. Here, we aimed to elucidate the mechanism through which ERα influences proliferation in breast cancer cells. Our results show that ERα protein is cell cycle-regulated in human breast cancer cells and that the presence of 17-β-estradiol (E2) in the culture medium shortened the cell cycle significantly (by 4.5 hours, P cycle duration were observed in the S and G2/M phases, whereas the G1 phase was indistinguishable under liganded and unliganded conditions. In addition, ERα knockdown in MCF-7 cells accelerated mitotic exit, whereas transfection of ERα-negative MDA-MB-231 cells with exogenous ERα significantly shortened the S and G2/M phases (by 9.1 hours, P cycle progression through the S and G2/M phases than fulvestrant does, presumably because of the destabilizing effect of fulvestrant on ERα protein. Together, these results show that ERα modulates breast cancer cell proliferation by regulating events during the S and G2/M phases of the cell cycle in a ligand-dependent fashion. These results provide the rationale for an effective treatment strategy that includes a cell cycle inhibitor in combination with a drug that lowers estrogen levels, such as an aromatase inhibitor, and an antiestrogen that does not result in the degradation of ERα, such as tamoxifen.

  13. Imiquimod activates p53-dependent apoptosis in a human basal cell carcinoma cell line.

    Science.gov (United States)

    Huang, Shi-Wei; Chang, Shu-Hao; Mu, Szu-Wei; Jiang, Hsin-Yi; Wang, Sin-Ting; Kao, Jun-Kai; Huang, Jau-Ling; Wu, Chun-Ying; Chen, Yi-Ju; Shieh, Jeng-Jer

    2016-03-01

    The tumor suppressor p53 controls DNA repair, cell cycle, apoptosis, autophagy and numerous other cellular processes. Imiquimod (IMQ), a synthetic toll-like receptor (TLR) 7 ligand for the treatment of superficial basal cell carcinoma (BCC), eliminates cancer cells by activating cell-mediated immunity and directly inducing apoptosis and autophagy in cancer cells. To evaluate the role of p53 in IMQ-induced cell death in skin cancer cells. The expression, phosphorylation and subcellular localization of p53 were detected by real-time PCR, luciferase reporter assay, cycloheximide chase analysis, immunoblotting and immunocytochemistry. Using BCC/KMC1 cell line as a model, the upstream signaling of p53 activation was dissected by over-expression of TLR7/8, the addition of ROS scavenger, ATM/ATR inhibitors and pan-caspase inhibitor. The role of p53 in IMQ-induced apoptosis and autophagy was assessed by genetically silencing p53 and evaluated by a DNA content assay, immunoblotting, LC3 puncta detection and acridine orange staining. IMQ induced p53 mRNA expression and protein accumulation, increased Ser15 phosphorylation, promoted nuclear translocation and up-regulated its target genes in skin cancer cells in a TLR7/8-independent manner. In BCC/KMC1 cells, the induction of p53 by IMQ was achieved through increased ROS production to stimulate the ATM/ATR-Chk1/Chk2 axis but was not mediated by inducing DNA damage. The pharmacological inhibition of ATM/ATR significantly suppressed IMQ-induced p53 activation and apoptosis. Silencing of p53 significantly decreased the IMQ-induced caspase cascade activation and apoptosis but enhanced autophagy. Mutant p53 skin cancer cell lines were more resistant to IMQ-induced apoptosis than wildtype p53 skin cancer cell lines. IMQ induced ROS production to stimulate ATM/ATR pathways and contributed to p53-dependent apoptosis in a skin basal cell carcinoma cell line BCC/KMC1. Copyright © 2015 Japanese Society for Investigative Dermatology

  14. Human rhabdomyosarcoma cell lines for rhabdomyosarcoma research: Utility and pitfalls

    Directory of Open Access Journals (Sweden)

    Ashley R.P. Hinson

    2013-07-01

    Full Text Available Rhabdomyosarcoma (RMS is the most common soft tissue sarcoma of childhood and adolescence. Despite intergroup clinical trials conducted in Europe and North America, outcomes for high risk patients with this disease have not significantly improved in the last several decades, and survival of metastatic or relapsed disease remains extremely poor. Accrual into new clinical trials is slow and difficult, so in vitro cell line research and in vivo xenograft models present an attractive alternative for preclinical research for this cancer type. Currently, 30 commonly used human RMS cell lines exist, with differing origins, karyotypes, histologies, and methods of validation. Selecting an appropriate cell line for RMS research has important implications for outcomes. There are also potential pitfalls in using certain cell lines including contamination with murine stromal cells, cross-contamination between cell lines, discordance between the cell line and its associated original tumor, imposter cell lines, and nomenclature errors that result in the circulation of two or more presumed unique cell lines that are actually from the same origin. These pitfalls can be avoided by testing for species-specific isoenzymes, microarray analysis, assays for subtype-specific fusion products, and short tandem repeat analysis.

  15. Human Rhabdomyosarcoma Cell Lines for Rhabdomyosarcoma Research: Utility and Pitfalls

    Science.gov (United States)

    Hinson, Ashley R. P.; Jones, Rosanne; Crose, Lisa E. S.; Belyea, Brian C.; Barr, Frederic G.; Linardic, Corinne M.

    2013-01-01

    Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma of childhood and adolescence. Despite intergroup clinical trials conducted in Europe and North America, outcomes for high risk patients with this disease have not significantly improved in the last several decades, and survival of metastatic or relapsed disease remains extremely poor. Accrual into new clinical trials is slow and difficult, so in vitro cell-line research and in vivo xenograft models present an attractive alternative for preclinical research for this cancer type. Currently, 30 commonly used human RMS cell lines exist, with differing origins, karyotypes, histologies, and methods of validation. Selecting an appropriate cell line for RMS research has important implications for outcomes. There are also potential pitfalls in using certain cell lines including contamination with murine stromal cells, cross-contamination between cell lines, discordance between the cell line and its associated original tumor, imposter cell lines, and nomenclature errors that result in the circulation of two or more presumed unique cell lines that are actually from the same origin. These pitfalls can be avoided by testing for species-specific isoenzymes, microarray analysis, assays for subtype-specific fusion products, and short tandem repeat analysis. PMID:23882450

  16. The Cell Cycle: An Activity Using Paper Plates to Represent Time Spent in Phases of the Cell Cycle

    Science.gov (United States)

    Scherer, Yvette D.

    2014-01-01

    In this activity, students are given the opportunity to combine skills in math and geometry for a biology lesson in the cell cycle. Students utilize the data they collect and analyze from an online onion-root-tip activity to create a paper-plate time clock representing a 24-hour cell cycle. By dividing the paper plate into appropriate phases of…

  17. Sorting of cells of the same size, shape, and cell cycle stage for a single cell level assay without staining

    Directory of Open Access Journals (Sweden)

    Yomo Tetsuya

    2006-06-01

    Full Text Available Abstract Background Single-cell level studies are being used increasingly to measure cell properties not directly observable in a cell population. High-performance data acquisition systems for such studies have, by necessity, developed in synchrony. However, improvements in sample purification techniques are also required to reveal new phenomena. Here we assessed a cell sorter as a sample-pretreatment tool for a single-cell level assay. A cell sorter is routinely used for selecting one type of cells from a heterogeneous mixture of cells using specific fluorescence labels. In this case, we wanted to select cells of exactly the same size, shape, and cell-cycle stage from a population, without using a specific fluorescence label. Results We used four light scatter parameters: the peak height and area of the forward scatter (FSheight and FSarea and side scatter (SSheight and SSarea. The rat pheochromocytoma PC12 cell line, a neuronal cell line, was used for all experiments. The living cells concentrated in the high FSarea and middle SSheight/SSarea fractions. Single cells without cell clumps were concentrated in the low SS and middle FS fractions, and in the higher FSheight/FSarea and SSheight/SSarea fractions. The cell populations from these viable, single-cell-rich fractions were divided into twelve subfractions based on their FSarea-SSarea profiles, for more detailed analysis. We found that SSarea was proportional to the cell volume and the FSarea correlated with cell roundness and elongation, as well as with the level of DNA in the cell. To test the method and to characterize the basic properties of the isolated single cells, sorted cells were cultured in separate wells. The cells in all subfractions survived, proliferated and differentiated normally, suggesting that there was no serious damage. The smallest, roundest, and smoothest cells had the highest viability. There was no correlation between proliferation and differentiation. NGF increases

  18. Characteristics of replication and radiation response of Aedes Albopictus cell line in vitro

    International Nuclear Information System (INIS)

    Lee, C.K.

    1974-01-01

    The radiosensitivity of the line of Aedes albopictus cells was investigated by scoring x-ray-induced chromosome aberrations as a function of dose and of time after irradiation as well as the modification by dose fractionation. In order to obtain these data, a series of studies, e.g., karyotype, cell life cycle, radiation- induced mitotic delay, and frequency and type of spontaneous aberrations, were carried out. Cells from this line had three pairs of chromosomes as a stem line chromosome number. The morphology of the chromosomes is metacentric. Somatic pairing between homologous chromosomes was observed as a common event and there was a high frequency of achromatic gaps on the chromosomes. These observations are in good agreement with those made in other laboratories. The generation time of A. albopictus cell line was approximately 32 hours, in which G 1 , S, and G 2 phases were 2 1 / 2 , 24 and 5 1 / 2 hours respectively. This generation time is in agreement with the population doubling time observed in our cell growth studies. By contrast, in most mammalian cells, G 1 usually is the longest phase and S is comparatively short. Dose fractionation studies indicated that A. albopictus cells in culture may have a faster chromosome repair system than mammalian and other cell systems. This may, at least in part; explain the difference in radiosensitivity between A. albopictus cell line and other cell systems. (Diss. Abstr.)

  19. Distinct mechanisms act in concert to mediate cell cycle arrest.

    Science.gov (United States)

    Toettcher, Jared E; Loewer, Alexander; Ostheimer, Gerard J; Yaffe, Michael B; Tidor, Bruce; Lahav, Galit

    2009-01-20

    In response to DNA damage, cells arrest at specific stages in the cell cycle. This arrest must fulfill at least 3 requirements: it must be activated promptly; it must be sustained as long as damage is present to prevent loss of genomic information; and after the arrest, cells must re-enter into the appropriate cell cycle phase to ensure proper ploidy. Multiple molecular mechanisms capable of arresting the cell cycle have been identified in mammalian cells; however, it is unknown whether each mechanism meets all 3 requirements or whether they act together to confer specific functions to the arrest. To address this question, we integrated mathematical models describing the cell cycle and the DNA damage signaling networks and tested the contributions of each mechanism to cell cycle arrest and re-entry. Predictions from this model were then tested with quantitative experiments to identify the combined action of arrest mechanisms in irradiated cells. We find that different arrest mechanisms serve indispensable roles in the proper cellular response to DNA damage over time: p53-independent cyclin inactivation confers immediate arrest, whereas p53-dependent cyclin downregulation allows this arrest to be sustained. Additionally, p21-mediated inhibition of cyclin-dependent kinase activity is indispensable for preventing improper cell cycle re-entry and endoreduplication. This work shows that in a complex signaling network, seemingly redundant mechanisms, acting in a concerted fashion, can achieve a specific cellular outcome.

  20. Regulation of cell cycle checkpoint kinase WEE1 by miR-195 in malignant melanoma.

    Science.gov (United States)

    Bhattacharya, A; Schmitz, U; Wolkenhauer, O; Schönherr, M; Raatz, Y; Kunz, M

    2013-06-27

    WEE1 kinase has been described as a major gate keeper at the G2 cell cycle checkpoint and to be involved in tumour progression in different malignant tumours. Here we analysed the expression levels of WEE1 in a series of melanoma patient samples and melanoma cell lines using immunoblotting, quantitative real-time PCR and immunohistochemistry. WEE1 expression was significantly downregulated in patient samples of metastatic origin as compared with primary melanomas and in melanoma cell lines of high aggressiveness as compared with cell lines of low aggressiveness. Moreover, there was an inverse correlation between the expression of WEE1 and WEE1-targeting microRNA miR-195. Further analyses showed that transfection of melanoma cell lines with miR-195 indeed reduced WEE1 mRNA and protein expression in these cells. Reporter gene analysis confirmed direct targeting of the WEE1 3' untranslated region (3'UTR) by miR-195. Overexpression of miR-195 in SK-Mel-28 melanoma cells was accompanied by WEE1 reduction and significantly reduced stress-induced G2-M cell cycle arrest, which could be restored by stable overexpression of WEE1. Moreover, miR-195 overexpression and WEE1 knockdown, respectively, increased melanoma cell proliferation. miR-195 overexpression also enhanced migration and invasiveness of melanoma cells. Taken together, the present study shows that WEE1 expression in malignant melanoma is directly regulated by miR-195. miR-195-mediated downregulation of WEE1 in metastatic lesions may help to overcome cell cycle arrest under stress conditions in the local tissue microenvironment to allow unrestricted growth of tumour cells.

  1. Radiation could induce p53-independent and cell cycle - unrelated apoptosis in 5-fluorouracil radiosensitized head and neck carcinoma cells

    International Nuclear Information System (INIS)

    Didelot, C.; Mirjolet, J.F.; Barberi-Heyob, M.; Ramacci, C.; Merlin, J.L.

    2002-01-01

    The effect of chemoresistance induction in radio sensitivity and cellular behavior after irradiation remains misunderstood. This study was designed to understand the relationship between radiation-induced cell cycle arrest, apoptosis, and radiosensitivity in KB cell line and KB3 subline selected after 5-fluorouracil (5FU) exposure. Exposure of KB cells to 5FU led to an increase in radiosensitivity. G 2 /M cell cycle arrest was observed in the two cell lines after irradiation. The radioresistant KB cell line reached the maximum arrest two hours before KB3. The cellular exit from this arrest was found to be related to the wild type p53 protein expression induction. After irradiation, only KB3 cell line underwent apoptosis. This apoptosis induction seemed to be independent of G 2 /M arrest exit, which was carried out later. The difference in radiosensitivity between KB and KB3 subline may result therefore from both a difference in apoptosis induction and a difference in G 2 /M arrest maximum duration. Moreover, 5FU exposure has led to an increase in constitutive p53 protein expression, which may be associated with an increase in basal apoptosis cell fraction. Given the existing correlation between radiosensitivity and the percentage of basal apoptosis. the constitutive p53 protein expression may be related to intrinsic radiosensitivity in our cellular model. (author)

  2. Cell cycle-dependent induction of autophagy, mitophagy and reticulophagy.

    Science.gov (United States)

    Tasdemir, Ezgi; Maiuri, M Chiara; Tajeddine, Nicolas; Vitale, Ilio; Criollo, Alfredo; Vicencio, José Miguel; Hickman, John A; Geneste, Olivier; Kroemer, Guido

    2007-09-15

    When added to cells, a variety of autophagy inducers that operate through distinct mechanisms and target different organelles for autophagic destruction (mitochondria in mitophagy, endoplasmic reticulum in reticulophagy) rarely induce autophagic vacuolization in more than 50% or the cells. Here we show that this heterogeneity may be explained by cell cycle-specific effects. The BH3 mimetic ABT737, lithium, rapamycin, tunicamycin or nutrient depletion stereotypically induce autophagy preferentially in the G(1) and S phases of the cell cycle, as determined by simultaneous monitoring of cell cycle markers and the cytoplasmic aggregation of GFP-LC3 in autophagic vacuoles. These results point to a hitherto neglected crosstalk between autophagic vacuolization and cell cycle regulation.

  3. Brucella abortus Cell Cycle and Infection Are Coordinated.

    Science.gov (United States)

    De Bolle, Xavier; Crosson, Sean; Matroule, Jean-Yves; Letesson, Jean-Jacques

    2015-12-01

    Brucellae are facultative intracellular pathogens. The recent development of methods and genetically engineered strains allowed the description of cell-cycle progression of Brucella abortus, including unipolar growth and the ordered initiation of chromosomal replication. B. abortus cell-cycle progression is coordinated with intracellular trafficking in the endosomal compartments. Bacteria are first blocked at the G1 stage, growth and chromosome replication being resumed shortly before reaching the intracellular proliferation compartment. The control mechanisms of cell cycle are similar to those reported for the bacterium Caulobacter crescentus, and they are crucial for survival in the host cell. The development of single-cell analyses could also be applied to other bacterial pathogens to investigate their cell-cycle progression during infection. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Authentication of M14 melanoma cell line proves misidentification of MDA‐MB‐435 breast cancer cell line

    Science.gov (United States)

    Korch, Christopher; Hall, Erin M.; Dirks, Wilhelm G.; Ewing, Margaret; Faries, Mark; Varella‐Garcia, Marileila; Robinson, Steven; Storts, Douglas; Turner, Jacqueline A.; Wang, Ying; Burnett, Edward C.; Healy, Lyn; Kniss, Douglas; Neve, Richard M.; Nims, Raymond W.; Reid, Yvonne A.; Robinson, William A.

    2017-01-01

    A variety of analytical approaches have indicated that melanoma cell line UCLA‐SO‐M14 (M14) and breast carcinoma cell line MDA‐MB‐435 originate from a common donor. This indicates that at some point in the past, one of these cell lines became misidentified, meaning that it ceased to correspond to the reported donor and instead became falsely identified (through cross‐contamination or other means) as a cell line from a different donor. Initial studies concluded that MDA‐MB‐435 was the misidentified cell line and M14 was the authentic cell line, although contradictory evidence has been published, resulting in further confusion. To address this question, we obtained early samples of the melanoma cell line (M14), a lymphoblastoid cell line from the same donor (ML14), and donor serum preserved at the originator's institution. M14 samples were cryopreserved in December 1975, before MDA‐MB‐435 cells were established in culture. Through a series of molecular characterizations, including short tandem repeat (STR) profiling and cytogenetic analysis, we demonstrated that later samples of M14 and MDA‐MB‐435 correspond to samples of M14 frozen in 1975, to the lymphoblastoid cell line ML14, and to the melanoma donor's STR profile, sex and blood type. This work demonstrates conclusively that M14 is the authentic cell line and MDA‐MB‐435 is misidentified. With clear provenance information and authentication testing of early samples, it is possible to resolve debates regarding the origins of problematic cell lines that are widely used in cancer research. PMID:28940260

  5. Potentially lethal damage repair in cell lines of radioresistant human tumours and normal skin fibroblasts

    International Nuclear Information System (INIS)

    Marchese, M.J.; Minarik, L.; Hall, E.J.; Zaider, M.

    1985-01-01

    Radiation cell survival data were obtained in vitro for three cell lines isolated from human tumours traditionally considered to be radioresistant-two melanomas and one osteosarcoma-as well as from a diploid skin fibroblast cell line. One melanoma cell line was much more radioresistant than the other, while the osteosarcoma and fibroblast cell lines were more radiosensitive than either. For cells growing exponentially, little potentially lethal damage repair (PLDR) could be demonstrated by comparing survival data for cells in which subculture was delayed by 6 h with those sub-cultured immediately after treatment. For the malignant cells in plateau phase, which in these cells might be better termed 'slowed growth phase', since an appreciable fraction of the cells are still cycling, a small amount of PLDR was observed, but not as much as reported by other investigators in the literature. The normal fibroblasts, which achieved a truer plateau phase in terms of noncycling cells, showed a significantly larger amount of PLDR than the tumour cells. (author)

  6. Tributyltin induces G2/M cell cycle arrest via NAD(+)-dependent isocitrate dehydrogenase in human embryonic carcinoma cells.

    Science.gov (United States)

    Asanagi, Miki; Yamada, Shigeru; Hirata, Naoya; Itagaki, Hiroshi; Kotake, Yaichiro; Sekino, Yuko; Kanda, Yasunari

    2016-04-01

    Organotin compounds, such as tributyltin (TBT), are well-known endocrine-disrupting chemicals (EDCs). We have recently reported that TBT induces growth arrest in the human embryonic carcinoma cell line NT2/D1 at nanomolar levels by inhibiting NAD(+)-dependent isocitrate dehydrogenase (NAD-IDH), which catalyzes the irreversible conversion of isocitrate to α-ketoglutarate. However, the molecular mechanisms by which NAD-IDH mediates TBT toxicity remain unclear. In the present study, we examined whether TBT at nanomolar levels affects cell cycle progression in NT2/D1 cells. Propidium iodide staining revealed that TBT reduced the ratio of cells in the G1 phase and increased the ratio of cells in the G2/M phase. TBT also reduced cell division cycle 25C (cdc25C) and cyclin B1, which are key regulators of G2/M progression. Furthermore, apigenin, an inhibitor of NAD-IDH, mimicked the effects of TBT. The G2/M arrest induced by TBT was abolished by NAD-IDHα knockdown. Treatment with a cell-permeable α-ketoglutarate analogue recovered the effect of TBT, suggesting the involvement of NAD-IDH. Taken together, our data suggest that TBT at nanomolar levels induced G2/M cell cycle arrest via NAD-IDH in NT2/D1 cells. Thus, cell cycle analysis in embryonic cells could be used to assess cytotoxicity associated with nanomolar level exposure of EDCs.

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

    Science.gov (United States)

    Arora, Shagun; Tandon, Simran

    2015-01-01

    In the present study, we investigated the anti-cancer effect of various potencies of Ruta graveolens (Ruta) on COLO-205 cell line, as evidenced by cytotoxicity, migration, clonogenecity, morphological and biochemical changes and modification in the levels of genes associated with apoptosis and cell cycle. On treatment of COLO-205 cells maximal effects were seen with mother tincture (MT) and 30C potencies, wherein decrease in cell viability along with reduced clonogenecity and migration capabilities were noted. In addition morphological and biochemical alterations such as nuclear changes (fragmented nuclei with condensed chromatin) and DNA ladder-like pattern (increased amount of fragmented DNA) in COLO-205 cells indicating apoptotic related cell death were seen. The expression of apoptosis and cell-cycle related regulatory genes assessed by reverse transcriptase-PCR revealed an up-regulation of caspase 9, caspase-3, Bax, p21 and p27 expression and down-regulation of Bcl-2 expression in treated cells. The mode of cell death was suggestive of intrinsic apoptotic pathway along with cell cycle arrest at the G2/M of the cell cycle. Our findings indicate that phytochemicals present in Ruta showed potential for natural therapeutic product development for colon carcinoma. Copyright © 2014 The Faculty of Homeopathy. Published by Elsevier Ltd. All rights reserved.

  8. Cytotoxic effect and radiation enhancement of artemisinin in uterine cervical carcinoma cell line HeLa

    International Nuclear Information System (INIS)

    Gong Xiaomei; Zhou Daoan; Cao Jianping; Fan Saijun; Zhu Wei

    2010-01-01

    Objective: To investigate cytotoxic and radiosensitizing effect of Artemisinin on cervical carcinoma cell line HeLa. Methods: In order to measure the optimized effective time, cytotoxic effect of Artemisinin on HeLa cell line was investigated with MTT assay. The radiosensitization effect of different doses and different treatment duration of Artemisinin on HeLa cell line were evaluated by MTT test, the SER is 1.17 and radiosensitizing effect was measured with multi-target single hit model through SER of HeLa cell. Cell cycles in different groups were calculated by flow cytometry. Results: The 50% inhibition concentration of Artemisinin interacted with HeLa cells for 24 h is 600.19 nmol/ml, and for 48 h is 160.71 nmol/ml. The HeLa cells'surival ratio is 93.51%, 91.87%, and 87.28% after adding Atemisinin of 110.69 nmol/ml and 1 Gy radiation exposure. There are three groups: the chemotherapy only group, the radiotherapy only group and the combination group. The result of the cell cycles showed that cells in G 2 /M period decreased in the combination group. Conclusion: Artemisinin has radiosensitization effect on cervical carcinoma HeLa cells, whichshows dose and time dependent. Artemisinin can inhibit the G 2 /M block by ionizing radiation. (authors)

  9. Trichloroethylene toxicity in a human hepatoma cell line

    Energy Technology Data Exchange (ETDEWEB)

    Thevenin, E.; McMillian, J. [Medical Univ. of Charleston South Carolina, SC (United States)

    1994-12-31

    The experiments conducted in this study were designed to determine the usefullness of hepatocyte cultures and a human hepatoma cell line as model systems for assessing human susceptibility to hepatocellular carcinoma due to exposure to trichloroethylene. The results from these studies will then be analyzed to determine if human cell lines can be used to conduct future experiments of this nature.

  10. Derivation of the human embryonic stem cell line RCM1

    Directory of Open Access Journals (Sweden)

    P.A. De Sousa

    2016-03-01

    Full Text Available The human embryonic stem cell line RCM-1 was derived from a failed to fertilise egg undergoing parthenogenetic stimulation. The cell line shows normal pluripotency marker expression and differentiation to three germ layers in vitro and in vivo. It has a normal 46XX female karyotype and microsatellite PCR identity, HLA and blood group typing data is available.

  11. Enhancing the Anti-tumor Activity of ErbB Blockers with Histone Deaccetylase(HDAC)Inhibition in Prostate Cancer Cell Lines

    National Research Council Canada - National Science Library

    Chinnaiyan, Prakash; Harari, Paul M

    2007-01-01

    .... Continuing work with additional prostate cancer cell lines and examining other biologic end-points, including cell cycle kinetics, angiogenesis, and invasion. Promising results will then be evaluated in vivo.

  12. Endothelial cell subpopulations in vitro: cell volume, cell cycle, and radiosensitivity

    International Nuclear Information System (INIS)

    Rubin, D.B.; Drab, E.A.; Bauer, K.D.

    1989-01-01

    Vascular endothelial cells (EC) are important clinical targets of radiation and other forms of free radical/oxidant stresses. In this study, we found that the extent of endothelial damage may be determined by the different cytotoxic responses of EC subpopulations. The following characteristics of EC subpopulations were examined: (1) cell volume; (2) cell cycle position; and (3) cytotoxic indexes for both acute cell survival and proliferative capacity after irradiation (137Cs, gamma, 0-10 Gy). EC cultured from bovine aortas were separated by centrifugal elutriation into subpopulations of different cell volumes. Through flow cytometry, we found that cell volume was related to the cell cycle phase distribution. The smallest EC were distributed in G1 phase and the larger cells were distributed in either early S, middle S, or late S + G2M phases. Cell cycle phase at the time of irradiation was not associated with acute cell loss. However, distribution in the cell cycle did relate to cell survival based on proliferative capacity (P less than 0.01). The order of increasing radioresistance was cells in G1 (D0 = 110 cGy), early S (135 cGy), middle S (145 cGy), and late S + G2M phases (180 cGy). These findings (1) suggest an age-related response to radiation in a nonmalignant differentiated cell type and (2) demonstrate EC subpopulations in culture

  13. In vitro synergistic antitumor efficacy of sequentially combined chemotherapy/icotinib in non‑small cell lung cancer cell lines.

    Science.gov (United States)

    Wang, Min-Cong; Liang, Xuan; Liu, Zhi-Yan; Cui, Jie; Liu, Ying; Jing, Li; Jiang, Li-Li; Ma, Jie-Qun; Han, Li-Li; Guo, Qian-Qian; Yang, Cheng-Cheng; Wang, Jing; Wu, Tao; Nan, Ke-Jun; Yao, Yu

    2015-01-01

    The concurrent administration of chemotherapy and epidermal growth factor receptor‑tyrosine kinase inhibitors (EGFR‑TKIs) has previously produced a negative interaction and failed to confer a survival benefit to non‑small cell lung cancer (NSCLC) patients compared with first‑line cytotoxic chemotherapy. The present study aimed to investigate the optimal schedule of the combined treatment of cisplatin/paclitaxel and icotinib in NSCLC cell lines and clarify the underlying mechanisms. HCC827, H1975, H1299 and A549 human NSCLC cell lines with wild‑type and mutant EGFR genes were used as in vitro models to define the differential effects of various schedules of cisplatin/paclitaxel with icotinib treatments on cell growth, proliferation, cell cycle distribution, apoptosis, and EGFR signaling pathway. Sequence‑dependent antiproliferative effects differed among the four NSCLC cell lines, and were not associated with EGFR mutation, constitutive expression levels of EGFR or downstream signaling molecules. The antiproliferative effect of cisplatin plus paclitaxel followed by icotinib was superior to that of cisplatin or paclitaxel followed by icotinib in the HCC827, H1975, H1299 and A549 cell lines, and induced more cell apoptosis and G0/G1 phase arrest. Cisplatin and paclitaxel significantly increased the expression of EGFR phosphorylation in the HCC827 cell line. However, only paclitaxel increased the expression of EGFR phosphorylation in the H1975 cell line. Cisplatin/paclitaxel followed by icotinib influenced the expression of p‑EGFR and p‑AKT, although the expression of p‑ERK1/2 remained unchanged. The results suggest that the optimal schedule of the combined treatment of cisplatin/paclitaxel and icotinib differed among the NSCLC cell lines. The results also provide molecular evidence to support clinical treatment strategies for NSCLC patients.

  14. Comparison of steroid receptors from the androgen responsive DDT1 cell line and the nonresponsive HVP cell line.

    Science.gov (United States)

    Norris, J S; Kohler, P O

    1978-01-01

    Two hamster cell lines have been isolated from androgen target tissue. The DDT1 cells derived from ductus deferens tissue exhibit a growth response to androgens, while the HVP cells derived from ventral prostate are androgen unresponsive. Both cell lines contain androgen receptors, that are similar when compared by kinetic methods, sedimentation velocity, chromatographic procedures or nuclear translocation ability. The forms of the high salt extracted nuclear receptors are indistinguishable chromatographically. Therefore, we postulate that the lesion preventing androgen induced growth in the HVP cell line is subseqent to nuclear translocation of the steroid receptor complex.

  15. Role of novel anticancer drug Roscovitine on enhancing radiosensitivity in carcinoma cell lines

    International Nuclear Information System (INIS)

    Noaman, E.; Sayed, H.M.; Medhat, A.M.; Morcos, N.Y.S.

    2010-01-01

    The present study was conducted to evaluate the radiosensitization effect of Roscovitine (cyclin dependent kinase inhibitor) in carcinoma cell lines. Three cell lines are used liver carcinoma cell line (HepG2), brain carcinoma cell line (U251), Lung carcinoma cell line (H460) in this study cells were treated with Roscovitine in different concentrations ranging from 0.1 ?M to 100 ?M before exposure to radiation doses ranging from 0.5 Gy to 20 Gy according to each experiment. The cell viability by MTT assay, the cell cycle analysis by flow cytometry and DNA fragmentation repair mechanism by diphenylamine were measured after Roscovitine treatment with or without radiation exposure to explore the sensitization effect of Roscovitine. The present study conclude that Roscovitine a good candidate as radiosensitizer for modifying the ionizing radiation (IR) response in cancer cells, beside its cyclin dependent kinase inhibitor function, Roscovitine can generate DNA Double strand Breaks and cooperate to enhance IR induce DNA damages. Roscovitine is currently in clinical trials, although our findings suggest that the combination of Roscovitine with IR appears to be a very promising especially for liver, brain and lung cancer treatment, further investigation is needed to evaluate the therapeutic index before tested in clinical trials

  16. Role of novel anticancer drug Roscovitine on enhancing radiosensitivity in carcinoma cell lines

    International Nuclear Information System (INIS)

    Mohamed, H.M.S.

    2009-01-01

    The present study was conducted to evaluate the radiosensitization effect of Roscovitine (cyclin dependent kinase inhibitor) in carcinoma cell lines. Three cell lines are used (HepG2 liver carcinoma cell line, U251 brain carcinoma cell line, H460 Lung carcinoma cell line) in this study .cells were treated with Roscovitine in different concentrations ranging from 0.1μM to 100 μM before exposure to radiation doses ranging from 0.5 Gy to 20 Gy according to each experiment. The cell viability by MTT assay, The cell cycle analysis by flow cytometry and DNA fragmentation repair mechanism by diphenylamine were measured after Roscovitine treatment with or without radiation to explore the sensitization effect of Roscovitine. The present study conclude that Roscovitine a good candidate as radiosensitizer for modifying the ionizing radiation (IR) response in cancer cells, beside its cyclin dependent kinase inhibitor function, roscovitine can generate DNA Double strand Breaks and cooperate to enhance IR induce DNA damages . Roscovitine is currently in clinical trials, although our findings suggest that the combination of Roscovitine with IR appears to be a very promising especially for liver, brain and lung cancer treatment, further investigation is needed to evaluate the therapeutic index before tested in clinical trial

  17. Protein kinase C signaling and cell cycle regulation

    Directory of Open Access Journals (Sweden)

    Adrian R Black

    2013-01-01

    Full Text Available A link between T cell proliferation and the protein kinase C (PKC family of serine/threonine kinases has been recognized for about thirty years. However, despite the wealth of information on PKC-mediated control of T cell activation, understanding of the effects of PKCs on the cell cycle machinery in this cell type remains limited. Studies in other systems have revealed important cell cycle-specific effects of PKC signaling that can either positively or negatively impact proliferation. The outcome of PKC activation is highly context-dependent, with the precise cell cycle target(s and overall effects determined by the specific isozyme involved, the timing of PKC activation, the cell type, and the signaling environment. Although PKCs can regulate all stages of the cell cycle, they appear to predominantly affect G0/G1 and G2. PKCs can modulate multiple cell cycle regulatory molecules, including cyclins, cyclin-dependent kinases (cdks, cdk inhibitors and cdc25 phosphatases; however, evidence points to Cip/Kip cdk inhibitors and D-type cyclins as key mediators of PKC-regulated cell cycle-specific effects. Several PKC isozymes can target Cip/Kip proteins to control G0/G1→S and/or G2→M transit, while effects on D-type cyclins regulate entry into and progression through G1. Analysis of PKC signaling in T cells has largely focused on its roles in T cell activation; thus, observed cell cycle effects are mainly positive. A prominent role is emerging for PKCθ, with non-redundant functions of other isozymes also described. Additional evidence points to PKCδ as a negative regulator of the cell cycle in these cells. As in other cell types, context-dependent effects of individual isozymes have been noted in T cells, and Cip/Kip cdk inhibitors and D-type cyclins appear to be major PKC targets. Future studies are anticipated to take advantage of the similarities between these various systems to enhance understanding of PKC-mediated cell cycle regulation in

  18. Cytotoxicity and cell-cycle effects of paclitaxel when used as a single agent and in combination with ionizing radiation

    International Nuclear Information System (INIS)

    Gupta, Nalin; Hu, Lily J.; Deen, Dennis F.

    1997-01-01

    Purpose: This study aimed to determine the extent of paclitaxel-induced cytotoxicity and cell-cycle perturbations when used alone and in combination with radiation in human glioma cells. Methods and Materials: The effect of paclitaxel alone on three human glioma cells lines--SF-126, U-87 MG, and U-251 MG--was assessed after 24, 48, 72, or 96 h treatment. For experiments in combination with radiation, cells were exposed to either a long (48-h) or short (8-h) duration of paclitaxel treatment prior to irradiation. Cell survival was determined by clonogenic assay. Cell cycle perturbations were assessed by using flow cytometry to measure the proportion of cells in G 1 , S, and G 2 /M phases. Results: When cells were treated with paclitaxel alone for ≥24 h, cytotoxicity increased up to a threshold dose, after which it plateaued. When treatment duration was ≤24 h, cytotoxicity was appreciably greater in U-251 MG cells than in SF-126 and U-87 MG cells. After 24 h of paclitaxel treatment, cells in plateau phase growth had increased survival compared to cells in log phase growth. In contrast, after 8 h paclitaxel treatment, mitotic cells had reduced survival compared to cells from an asynchronous population. Cell-cycle perturbations were consistent with the presence of a mitotic block after paclitaxel treatment, although changes in other cell-cycle phase fractions varied among cell lines. For experiments in combination with radiation, cytotoxicity was increased when cells were irradiated after 48 h of paclitaxel treatment but not after 8 h of treatment. Conclusion: The duration of paclitaxel treatment and the location of cells in the cell cycle modify the degree of radiation cytotoxicity. The mechanisms of paclitaxel cytotoxicity are likely to be multifactorial because varying effects are seen in different cell lines. Furthermore, it is clear that simply increasing the number of cells in G 2 /M is insufficient in itself to increase the response of cells to radiation

  19. Identification of a novel rhabdovirus in Spodoptera frugiperda cell lines.

    Science.gov (United States)

    Ma, Hailun; Galvin, Teresa A; Glasner, Dustin R; Shaheduzzaman, Syed; Khan, Arifa S

    2014-06-01

    The Sf9 cell line, derived from Spodoptera frugiperda, is used as a cell substrate for biological products, and no viruses have been reported in this cell line after extensive testing. We used degenerate PCR assays and massively parallel sequencing (MPS) to identify a novel RNA virus belonging to the order Mononegavirales in Sf9 cells. Sequence analysis of the assembled virus genome showed the presence of five open reading frames (ORFs) corresponding to the genes for the N, P, M, G, and L proteins in other rhabdoviruses and an unknown ORF of 111 amino acids located between the G- and L-protein genes. BLAST searches indicated that the S. frugiperda rhabdovirus (Sf-rhabdovirus) was related in a limited region of the L-protein gene to Taastrup virus, a newly discovered member of the Mononegavirales from a leafhopper (Hemiptera), and also to plant rhabdoviruses, particularly in the genus Cytorhabdovirus. Phylogenetic analysis of sequences in the L-protein gene indicated that Sf-rhabdovirus is a novel virus that branched with Taastrup virus. Rhabdovirus morphology was confirmed by transmission electron microscopy of filtered supernatant samples from Sf9 cells. Infectivity studies indicated potential transient infection by Sf-rhabdovirus in other insect cell lines, but there was no evidence of entry or virus replication in human cell lines. Sf-rhabdovirus sequences were also found in the Sf21 parental cell line of Sf9 cells but not in other insect cell lines, such as BT1-TN-5B1-4 (Tn5; High Five) cells and Schneider's Drosophila line 2 [D.Mel.(2); SL2] cells, indicating a species-specific infection. The results indicate that conventional methods may be complemented by state-of-the-art technologies with extensive bioinformatics analysis for identification of novel viruses. The Spodoptera frugiperda Sf9 cell line is used as a cell substrate for the development and manufacture of biological products. Extensive testing has not previously identified any viruses in this cell

  20. A methodology for on line fatigue life monitoring : rainflow cycle counting method

    International Nuclear Information System (INIS)

    Mukhopadhyay, N.K.; Dutta, B.K.; Kushwaha, H.S.

    1992-01-01

    Green's function technique is used in on line fatigue life monitoring to convert plant data to stress versus time data. This technique converts plant data most efficiently to stress versus time data. To compute the fatigue usage factor the actual number of cycles experienced by the component is to be found out from stress versus time data. Using material fatigue properties the fatigue usage factor is to be computed from the number of cycles. Generally the stress response is very irregular in nature. To convert an irregular stress history to stress frequency spectra rainflow cycle counting method is used. This method is proved to be superior to other counting methods and yields best fatigue estimates. A code has been developed which computes the number of cycles experienced by the component from stress time history using rainflow cycle counting method. This postprocessor also computes the accumulated fatigue usage factor from material fatigue properties. The present report describes the development of a code to compute fatigue usage factor using rainflow cycle counting technique and presents a real life case study. (author). 10 refs., 10 figs

  1. Dose-rate effects on the cell cycle and survival of S3 HeLa and V79 cells

    International Nuclear Information System (INIS)

    Mitchell, J.B.; Bedford, J.S.; Bailey, S.M.

    1979-01-01

    The effects of continuous irradiation at different dose rates on the cell cycle and on cell survival were studied using synchronized S3 HeLa and V79 cells. The minimum dose rate necessary to stop cell division was found to be approximately 23 rad/hr for HeLa cells and 270 rad/hr for V79 cells. For dose rates that stop cell division, cells progress through G 1 and S, with a small delay in the S phase, and are blocked in G 2 . Appreciable mitotic accumulation was observed for HeLa cells at dose rates which stopped cell division. By comparison, much less mitotic accumulation was observed for V79 cells over a range of dose rates from 37 to 270 rad/hr. Minimum mitotic delays for a variety of dose rates were determined for both cell lines. S3 HeLa cells are much more sensitive in this respect than V79 cells; however, it appeared that for higher dose rates the minimum mitotic delay in HeLa cells asymptotically approached a value of about 35 hr. In addition to the qualitative differences observed for the two cell lines in regard to mitotic accumulation, HeLa cells accumulated for prolonged periods in the presence of colcemid while V79 cells were blocked for only a few hours, HeLa cells show a dramatic effect of redistribution of cells into sensitive phases of the cell cycle during exposure, which was reflected in the survival curves at low dose rate. More cell killing per unit dose was observed at 37 than at 74 rad/hr

  2. Analysis of the Budding Yeast Cell Cycle by Flow Cytometry.

    Science.gov (United States)

    Rosebrock, Adam P

    2017-01-03

    DNA synthesis is one of the landmark events in the cell cycle: G 1 cells have one copy of the genome, S phase cells are actively engaged in DNA synthesis, and G 2 cells have twice as much nuclear DNA as G 1 cells. Cellular DNA content can be measured by staining with a fluorescent dye followed by a flow-cytometric readout. This method provides a quantitative measurement of cell cycle position on a cell-by-cell basis at high speed. Using flow cytometry, tens of thousands of single-cell measurements can be generated in a few seconds. This protocol details staining of cells of the budding yeast Saccharomyces cerevisiae for flow cytometry using Sytox Green dye in a method that can be scaled widely-from one sample to many thousands and operating on inputs ranging from 1 million to more than 100 million cells. Flow cytometry is preferred over light microscopy or Coulter analyses for the analysis of the cell cycle as DNA content and cell cycle position are being directly measured. © 2017 Cold Spring Harbor Laboratory Press.

  3. Polymer encapsulated dopaminergic cell lines as "alternative neural grafts".

    Science.gov (United States)

    Jaeger, C B; Greene, L A; Tresco, P A; Winn, S R; Aebischer, P

    1990-01-01

    Our preliminary findings (Jaeger et al., 1988; Aebischer et al., 1989; Tresco et al., 1989) and the studies in progress show that encapsulated dopaminergic cell lines survive enclosure within a semi-permeable membrane. The encapsulated cells remained viable for extended time periods when maintained in vitro. Moreover, encapsulated PC12 and T28 cells have the potential to survive following their implantation into the forebrain of rats. Cell lines are essentially "immortal" because they continue to divide indefinitely. This property allows perpetual "self-renewal" of a given cell population. However, the capacity of continuous uncontrolled cell division may also lead to tumor formation. This in fact is the case for unencapsulated PC12 cell implants placed into the brain of young Sprague Dawley rats (Jaeger, 1985). Cell line encapsulation has the potential to prevent tumor growth (Jaeger et al., 1988). Survival for 6 months in vitro suggests that encapsulation does not preclude long-term maintenance of an homogeneous cell line like PC12 cells. The presence of mitotic figures in the capsules further supports the likelihood of propagation and self renewal of the encapsulated population. Another significant property of cell lines is that they consist of a single, genetically homogeneous cell type. They do not require specific synaptic interactions for their survival. In the case of PC12 and T28 lines, the cells synthesize and release neurotransmitters. Our data show that PC12 and T28 cells continue to release dopamine spontaneously and to express specific transmitters and enzymes following encapsulation. Thus, cell lines such as these may constitute relatively simple "neural implants" exerting their function via humoral release.(ABSTRACT TRUNCATED AT 250 WORDS)

  4. The Mammalian Cell Cycle Regulates Parvovirus Nuclear Capsid Assembly

    Science.gov (United States)

    Riolobos, Laura; Domínguez, Carlos; Kann, Michael; Almendral, José M.

    2015-01-01

    It is unknown whether the mammalian cell cycle could impact the assembly of viruses maturing in the nucleus. We addressed this question using MVM, a reference member of the icosahedral ssDNA nuclear parvoviruses, which requires cell proliferation to infect by mechanisms partly understood. Constitutively expressed MVM capsid subunits (VPs) accumulated in the cytoplasm of mouse and human fibroblasts synchronized at G0, G1, and G1/S transition. Upon arrest release, VPs translocated to the nucleus as cells entered S phase, at efficiencies relying on cell origin and arrest method, and immediately assembled into capsids. In synchronously infected cells, the consecutive virus life cycle steps (gene expression, proteins nuclear translocation, capsid assembly, genome replication and encapsidation) proceeded tightly coupled to cell cycle progression from G0/G1 through S into G2 phase. However, a DNA synthesis stress caused by thymidine irreversibly disrupted virus life cycle, as VPs became increasingly retained in the cytoplasm hours post-stress, forming empty capsids in mouse fibroblasts, thereby impairing encapsidation of the nuclear viral DNA replicative intermediates. Synchronously infected cells subjected to density-arrest signals while traversing early S phase also blocked VPs transport, resulting in a similar misplaced cytoplasmic capsid assembly in mouse fibroblasts. In contrast, thymidine and density arrest signals deregulating virus assembly neither perturbed nuclear translocation of the NS1 protein nor viral genome replication occurring under S/G2 cycle arrest. An underlying mechanism of cell cycle control was identified in the nuclear translocation of phosphorylated VPs trimeric assembly intermediates, which accessed a non-conserved route distinct from the importin α2/β1 and transportin pathways. The exquisite cell cycle-dependence of parvovirus nuclear capsid assembly conforms a novel paradigm of time and functional coupling between cellular and virus life

  5. Molecular Mechanisms by Which a Fucus vesiculosus Extract Mediates Cell Cycle Inhibition and Cell Death in Pancreatic Cancer Cells

    Directory of Open Access Journals (Sweden)

    Ulf Geisen

    2015-07-01

    Full Text Available Pancreatic cancer is one of the most aggressive cancer entities, with an extremely poor 5-year survival rate. Therefore, novel therapeutic agents with specific modes of action are urgently needed. Marine organisms represent a promising source to identify new pharmacologically active substances. Secondary metabolites derived from marine algae are of particular interest. The present work describes cellular and molecular mechanisms induced by an HPLC-fractionated, hydrophilic extract derived from the Baltic brown seaweed Fucus vesiculosus (Fv1. Treatment with Fv1 resulted in a strong inhibition of viability in various pancreatic cancer cell lines. This extract inhibited the cell cycle of proliferating cells due to the up-regulation of cell cycle inhibitors, shown on the mRNA (microarray data and protein level. As a result, cells were dying in a caspase-independent manner. Experiments with non-dividing cells showed that proliferation is a prerequisite for the effectiveness of Fv1. Importantly, Fv1 showed low cytotoxic activity against non-malignant resting T cells and terminally differentiated cells like erythrocytes. Interestingly, accelerated killing effects were observed in combination with inhibitors of autophagy. Our in vitro data suggest that Fv1 may represent a promising new agent that deserves further development towards clinical application.

  6. Studies on regulation of the cell cycle in fission yeast.

    Directory of Open Access Journals (Sweden)

    Miroslava Požgajová

    2015-05-01

    Full Text Available All living organisms including plants and animals are composed of millions of cells. These cells perform different functions for the organism although they possess the same chromosomes and carry the same genetic information. Thus, to be able to understand multicellular organism we need to understand the life cycle of individual cells from which the organism comprises. The cell cycle is the life cycle of a single cell in the plant or animal body. It involves series of events in which components of the cell doubles and afterwards equally segregate into daughter cells. Such process ensures growth of the organism, and specialized reductional cell division which leads to production of gamets, assures sexual reproduction. Cell cycle is divided in the G1, S, G2 and M phase. Two gap-phases (G1 and G2 separate S phase (or synthesis and M phase which stays either for mitosis or meiosis. Essential for normal life progression and reproduction is correct chromosome segregation during mitosis and meiosis. Defects in the division program lead to aneuploidy, which in turn leads to birth defects, miscarriages or cancer. Even thou, researchers invented much about the regulation of the cell cycle, there is still long way to understand the complexity of the regulatory machineries that ensure proper segregation of chromosomes. In this paper we would like to describe techniques and materials we use for our studies on chromosome segregation in the model organism Schizosaccharomyces pombe.

  7. Isolation and characterization of a radiosensitive Chinese hamster ovary cell line

    International Nuclear Information System (INIS)

    Fuller, L.F.

    1987-01-01

    A x-ray sensitive Chinese hamster ovary cell line was isolated using a semi-automated procedure in which mutagenized CHO cells were allowed to form colonies on top of agar, x-irradiated, then photographed at two later times. Comparison of the photographs allowed the identification of colonies which displayed significant growth arrest. One of the colonies identified in this manner produced a stable, radiosensitive line. This cell line is normal in x-ray induced inhibition of DNA synthesis, and single- and double-strand break repair, and is moderately sensitive to ethyl methane sulfonate and UV light. The sensitive line performs only half as much x-ray-induced repair replication as the parental line and this deficiency is believed to be the primary cause of its radiosensitivity. The sensitive line produces significantly higher numbers of x-ray-induced chromosome and chromatid aberrations including chromatid aberrations following exposure during the G 1 phase of the cell cycle. The line is hypomutable compared to the parental line with x-ray exposure inducing only one-third as many 6-thioguanine resistant colonies

  8. Recombinant protein production from stable mammalian cell lines and pools.

    Science.gov (United States)

    Hacker, David L; Balasubramanian, Sowmya

    2016-06-01

    We highlight recent developments for the production of recombinant proteins from suspension-adapted mammalian cell lines. We discuss the generation of stable cell lines using transposons and lentivirus vectors (non-targeted transgene integration) and site-specific recombinases (targeted transgene integration). Each of these methods results in the generation of cell lines with protein yields that are generally superior to those achievable through classical plasmid transfection that depends on the integration of the transfected DNA by non-homologous DNA end-joining. This is the main reason why these techniques can also be used for the generation of stable cell pools, heterogenous populations of recombinant cells generated by gene delivery and genetic selection without resorting to single cell cloning. This allows the time line from gene transfer to protein production to be reduced. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Susceptibility of various cell lines to Neospora caninum tachyzoites cultivation

    Directory of Open Access Journals (Sweden)

    Khordadmehr, M.,

    2014-05-01

    Full Text Available Neospora caninum is a coccidian protozoan parasite which is a major cause of bovine abortions and neonatal mortality in cattle, sheep, goat and horse. Occasionally, cultured cells are used for isolation and multiplication of the agent in vitro with several purposes. In this study the tachyzoite yields of N. caninum were compared in various cell cultures as the host cell lines. Among the cell cultures tested, two presented good susceptibility to the agent: cell lines Vero and MA-104. SW742 and TLI (in vitro suspension culture of lymphoid cells infected with Theileria lestoquardi showed moderate sensitivity. No viable tachyzoite were detected in the culture of MDCK and McCoy cell lines. These results demonstrate that MA-104 and SW742 cells present adequate susceptibility to N. caninum compared to Vero cells, which have been largely used to multiply the parasite in vitro. Moreover, these have easy manipulation, fast multiplication and relatively low nutritional requirements. In addition, the result of this study showed that TLI cell line as a suspension cell culture is susceptible to Nc-1 tachyzoites infection and could be used as an alternative host cell line for tachyzoites culture in vitro studies.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-01-15

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

  11. Attenuation of G2 cell cycle checkpoint control in human tumor cells is associated with increased frequencies of unrejoined chromosome breaks but not increased cytotoxicity following radiation exposure

    International Nuclear Information System (INIS)

    Schwartz, J.L.; Cowan, J.; Grdina, D.J.

    1997-01-01

    The contribution of G 2 cell cycle checkpoint control to ionizing radiation responses was examined in ten human tumor cell lines. Most of the delay in cell cycle progression seen in the first cell cycle following radiation exposure was due to blocks in G 2 and there were large cell line-to-cell line variations in the length of the G 2 block. Longer delays were seen in cell lines that had mutations in p53. There was a highly significant inverse correlation between the length of G 2 delay and the frequency of unrejoined chromosome breaks seen as chromosome terminal deletions in mitosis, and observation that supports the hypothesis that the signal for G 2 delay in mammalian cells is an unrejoined chromosome break. There were also an inverse correlation between the length of G 2 delay and the level of chromosome aneuploidy in each cell line, suggesting that the G 2 and mitotic spindel checkpoints may be linked to each other. Attenuation in G 2 checkpoint control was not associated with alterations in either the frequency of induced chromosome rearrangements or cell survival following radiation exposure suggesting that chromosome rearrangements, the major radiation-induced lethal lesion in tumor cells, form before cells enters G 2 . Thus, agents that act solely to override G 2 arrest should produce little radiosensitization in human tumor cells

  12. Cytotoxicity of arctigenin and matairesinol against the T-cell lymphoma cell line CCRF-CEM.

    Science.gov (United States)

    Su, Shan; Cheng, Xinlai; Wink, Michael

    2015-09-01

    Arctigenin and matairesinol possess a diversity of bioactivities. Here we investigated the cytotoxicity of arctigenin and matairesinol against a T-cell lymphoma cell line CCRF-CEM and the underlying mechanisms that have not been explored before. The cytotoxic activity was investigated using MTT assay. The cell cycle arrest and reactive oxygen species (ROS) accumulation were determined by flow cytometric analysis. The apoptosis induction was assessed using Annexin V/Propidium Iodide assay. The gene quantification analysis was measured through real-time polymerase chain reaction. Arctigenin and matairesinol exhibited significant antiproliferative activity against CCRF-CEM cells after 72 h treatment with IC50 values of 1.21 ± 0.15 μm and 4.27 ± 0.41 μm, respectively. In addition, both lignans arrest CCRF-CEM cells in the S phase. Furthermore, they could induce apoptosis in CCRF-CEM cells in a concentration- and time-dependent manner. Interestingly, the lignans differentially regulated the expression of several key genes involved in apoptosis pathways, including Bax, Bad and caspase-9. Moreover, both lignans could increase ROS levels in CCRF-CEM cells. Our study provides an insight into the potential of arctigenin and matairesinol as good candidates for the development of novel agents against T-cell lymphoma. © 2015 Royal Pharmaceutical Society.

  13. Reduction of the Earth's magnetic field inhibits growth rates of model cancer cell lines.

    Science.gov (United States)

    Martino, Carlos F; Portelli, Lucas; McCabe, Kevin; Hernandez, Mark; Barnes, Frank

    2010-12-01

    Small alterations in static magnetic fields have been shown to affect certain chemical reaction rates ex vivo. In this manuscript, we present data demonstrating that similar small changes in static magnetic fields between individual cell culture incubators results in significantly altered cell cycle rates for multiple cancer-derived cell lines. This change as assessed by cell number is not a result of apoptosis, necrosis, or cell cycle alterations. While the underlying mechanism is unclear, the implications for all cell culture experiments are clear; static magnetic field conditions within incubators must be considered and/or controlled just as one does for temperature, humidity, and carbon dioxide concentration. Copyright © 2010 Wiley-Liss, Inc.

  14. Natural killer cells for immunotherapy – Advantages of cell lines over blood NK cells

    Directory of Open Access Journals (Sweden)

    Hans eKlingemann

    2016-03-01

    Full Text Available Natural killer cells are potent cytotoxic effector cells for cancer therapy and potentially for severe viral infections. However, there are technical challenges to obtain sufficient numbers of functionally active NK cells form a patient’s blood since they represent only 10% of the lymphocytes. Especially, cancer patients are known to have dysfunctional NK cells. The alternative is to obtain cells from a healthy donor, which requires depletion of the allogeneic T-cells. Establishing cell lines from donor blood NK cells have not been successful, in contrast to blood NK cells obtained from patients with a clonal NK cell lymphoma. Those cells can be expanded in culture in the presence of IL-2. However, except for the NK-92 cell line none of the other six known cell lines has consistent and reproducibly high anti-tumor cytotoxicity, nor can they be easily genetically manipulated to recognize specific tumor antigens or to augment monoclonal antibody activity through ADCC. NK-92 is also the only cell line product that has been widely given to patients with advanced cancer with demonstrated efficiency and minimal side effects.

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

    DEFF Research Database (Denmark)

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

    2011-01-01

    The SSX family of cancer and germline antigens is mainly expressed in the germ cells of healthy individuals as well as wide range of cancers and is therefore potential targets for immunotherapy. However, little is known about the role of SSX proteins in tumorigenesis and normal cell function. Here......, we show that SSX2 is involved in regulation of cancer cell growth. We found that ectopic expression of SSX2 in melanoma and colon cancer cells strongly reduced cell growth and induced apoptosis in vitro. Importantly, in a xenograft mouse model, the growth of tumors derived from SSX2 overexpressing...... melanoma cells was severely reduced compared to those derived from the isogenic parental cell line. Cell cycle analysis showed that SSX2 caused an accumulation of cells arrested in G1. Consistent with this, we observed a marked decrease in cells expressing the proliferation marker Ki67 and concomitantly...

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

    International Nuclear Information System (INIS)

    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.

    2006-01-01

    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

  17. Application of DNA fingerprints for cell-line individualization.

    Science.gov (United States)

    Gilbert, D A; Reid, Y A; Gail, M H; Pee, D; White, C; Hay, R J; O'Brien, S J

    1990-09-01

    DNA fingerprints of 46 human cell lines were derived using minisatellite probes for hypervariable genetic loci. The incidence of 121 HaeIII DNA fragments among 33 cell lines derived from unrelated individuals was used to estimate allelic and genotypic frequencies for each fragment and for composite individual DNA fingerprints. We present a quantitative estimate of the extent of genetic difference between individuals, an estimate based on the percentage of restriction fragments at which they differ. The average percent difference (APD) among pairwise combinations from the population of 33 unrelated cell lines was 76.9%, compared with the APD in band sharing among cell lines derived from the same individual (less than or equal to 1.2%). Included in this survey were nine additional cell lines previously implicated as HeLa cell derivatives, and these lines were clearly confirmed as such by DNA fingerprints (APD less than or equal to 0.6%). On the basis of fragment frequencies in the tested cell line population, a simple genetic model was developed to estimate the frequencies of each DNA fingerprint in the population. The median incidence was 2.9 X 10(-17), and the range was 2.4 X 10(-21) to 6.6 X 10(-15). This value approximates the probability that a second cell line selected at random from unrelated individuals will match a given DNA fingerprint. Related calculations address the chance that any two DNA fingerprints would be identical among a large group of cell lines. This estimate is still very slight; for example, the chance of two or more common DNA fingerprints among 1 million distinct individuals is less than .001. The procedure provides a straightforward, easily interpreted, and statistically robust method for identification and individualization of human cells.

  18. Inhibition of exportin-1 function results in rapid cell cycle-associated DNA damage in cancer cells.

    Science.gov (United States)

    Burke, Russell T; Marcus, Joshua M; Orth, James D

    2017-06-13

    Selective inhibitors of nuclear export (SINE) are small molecules in development as anti-cancer agents. The first-in-class SINE, selinexor, is in clinical trials for blood and solid cancers. Selinexor forms a covalent bond with exportin-1 at cysteine-528, and blocks its ability to export cargos. Previous work has shown strong cell cycle effects and drug-induced cell death across many different cancer-derived cell lines. Here, we report strong cell cycle-associated DNA double-stranded break formation upon the treatment of cancer cells with SINE. In multiple cell models, selinexor treatment results in the formation of clustered DNA damage foci in 30-40% of cells within 8 hours that is dependent upon cysteine-528. DNA damage strongly correlates with G1/S-phase and decreased DNA replication. Live cell microscopy reveals an association between DNA damage and cell fate. Cells that form damage in G1-phase more often die or arrest, while those damaged in S/G2-phase frequently progress to cell division. Up to half of all treated cells form damage foci, and most cells that die after being damaged, were damaged in G1-phase. By comparison, non-transformed cell lines show strong cell cycle effects but little DNA damage and less death than cancer cells. Significant drug combination effects occur when selinexor is paired with different classes of agents that either cause DNA damage or that diminish DNA damage repair. These data present a novel effect of exportin-1 inhibition and provide a strong rationale for multiple combination treatments of selinexor with agents that are currently in use for the treatment of different solid cancers.

  19. Activation of mammalian target of rapamycin signaling promotes cell cycle progression and protects cells from apoptosis in mantle cell lymphoma.

    Science.gov (United States)

    Peponi, Evangelia; Drakos, Elias; Reyes, Guadalupe; Leventaki, Vasiliki; Rassidakis, George Z; Medeiros, L Jeffrey

    2006-12-01

    Mantle cell lymphoma (MCL) is characterized by the t(11;14) and cyclin D1 overexpression. However, additional molecular events are most likely required for oncogenesis, possibly through cell cycle and apoptosis deregulation. We hypothesized that mammalian target of rapamycin (mTOR) is activated in MCL and contributes to tumor proliferation and survival. In MCL cell lines, pharmacological inhibition of the phosphoinositide 3-kinase/AKT pathway was associated with decreased phosphorylation (activation) of mTOR and its downstream targets phosphorylated (p)-4E-BP1, p-p70S6 kinase, and p-ribosomal protein S6, resulting in apoptosis and cell cycle arrest. These changes were associated with down-regulation of cyclin D1 and the anti-apoptotic proteins cFLIP, BCL-XL, and MCL-1. Furthermore, silencing of mTOR expression using mTOR-specific short interfering RNA decreased phosphorylation of mTOR signaling proteins and induced cell cycle arrest and apoptosis. Silencing of eukaryotic initiation factor (eIF4E), a downstream effector of mTOR, recapitulated these results. We also assessed mTOR signaling in MCL tumors using immunohistochemical methods and a tissue microarray: 10 of 30 (33%) expressed Ser473p-AKT, 13 of 21 (62%) Ser2448p-mTOR, 22 of 22 (100%) p-p70S6K, and 5 of 20 (25%) p-ribosomal protein S6. Total eIF4E binding protein 1 and eukaryotic initiation factor 4E were expressed in 13 of 14 (93%) and 16 of 29 (55%) MCL tumors, respectively. These findings suggest that the mTOR signaling pathway is activated and may contribute to cell cycle progression and tumor cell survival in MCL.

  20. Performances of Saft Lithium-Ion Cells in LEO Cycling

    Directory of Open Access Journals (Sweden)

    Prevot D.

    2017-01-01

    The article will thus present the whole LEO cycling results available for the two cells, and will provide afterwards the correlation status of Saft Li-ion Model (SLIM with all the experimental data acquired.

  1. Cellular Clocks : Coupled Circadian Dispatch and Cell Division Cycles

    NARCIS (Netherlands)

    Merrow, Martha; Roenneberg, Till

    2004-01-01

    Gating of cell division by the circadian clock is well known, yet its mechanism is little understood. Genetically tractable model systems have led to new hypotheses and questions concerning the coupling of these two cellular cycles.

  2. GLI1 is involved in cell cycle regulation and proliferation of NT2 embryonal carcinoma stem cells

    DEFF Research Database (Denmark)

    Vestergaard, Janni; Lind-Thomsen, Allan; Pedersen, Mikkel W.

    2008-01-01

    of altered HH signaling are interpreted by specific cell types. We have investigated the role of the HH transcription factor glioma-associated oncogene homolog 1 (GLI1) in the human Ntera2=D1 (NT2) embryonal carcinoma stem cell line. The study revealed that expression of GLI1 and its direct transcriptional......1 phase cyclins. In conclusion, our results suggest that GLI1 is involved in cell cycle and proliferation control in the embryonal carcinoma stem cell line NT2....... target Patched (PTCH) is downregulated in the early stages of retinoic acid-induced neuronal differentiation of NT2 cells. To identify transcriptional targets of the HH transcription factor GLI1 in NT2 cells, we performed global expression profiling following GLI1 RNA interference (RNAi). Of the similar...

  3. Radiation sensitivity of human lung cancer cell lines

    International Nuclear Information System (INIS)

    Carmichael, J.; Degraff, W.G.; Gamson, J.; Russo, G.; Mitchell, J.B.; Gazdar, A.F.; Minna, J.D.; Levitt, M.L.

    1989-01-01

    X-Ray survival curves were determined using a panel of 17 human lung cancer cell lines, with emphasis on non-small cell lung cancer (NSCLC). In contrast to classic small cell lung cancer (SCLC) cell lines, NSCLC cell lines were generally less sensitive to radiation as evidenced by higher radiation survival curve extrapolation numbers, surviving fraction values following a 2Gy dose (SF2) and the mean inactivation dose values (D) values. The spectrum of in vitro radiation responses observed was similar to that expected in clinical practice, although mesothelioma was unexpectedly sensitive in vitro. Differences in radiosensitivity were best distinguished by comparison of SF2 values. Some NSCLC lines were relatively sensitive, and in view of this demonstrable variability in radiation sensitivity, the SF2 value may be useful for in vitro predictive assay testing of clinical specimens. (author)

  4. Keith's MAGIC: Cloning and the Cell Cycle.

    Science.gov (United States)

    Wells, D N

    2013-10-01

    Abstract Professor Keith Campbell's critical contribution to the discovery that a somatic cell from an adult animal can be fully reprogrammed by oocyte factors to form a cloned individual following nuclear transfer (NT)(Wilmut et al., 1997 ) overturned a dogma concerning the reversibility of cell fate that many scientists had considered to be biologically impossible. This seminal experiment proved the totipotency of adult somatic nuclei and finally confirmed that adult cells could differentiate without irreversible changes to the genetic material.

  5. CXCR3 surface expression in human airway epithelial cells: cell cycle dependence and effect on cell proliferation.

    Science.gov (United States)

    Aksoy, Mark O; Yang, Yi; Ji, Rong; Reddy, P J; Shahabuddin, Syed; Litvin, Judith; Rogers, Thomas J; Kelsen, Steven G

    2006-05-01

    We recently demonstrated that human bronchial epithelial cells (HBEC) constitutively express the CXC chemokine receptor CXCR3, which when activated, induces directed cell migration. The present study in HBEC examined the relative expression of the CXCR3 splice variants CXCR3-A and -B, cell cycle dependence of CXCR3 expression, and the effects of the CXCR3 ligand, the interferon-gamma-inducible CXC chemokine I-TAC/CXCL11, on DNA synthesis and cell proliferation. Both CXCR3-A and -B mRNA, assessed by real-time RT-PCR, were expressed in normal HBEC (NHBEC) and the HBEC line 16-HBE. However, CXCR3-B mRNA was 39- and 6-fold greater than CXCR3-A mRNA in NHBEC and 16-HBE, respectively. Although most HBEC (>80%) assessed by flow cytometry and immunofluorescence microscopy contained intracellular CXCR3, only a minority (75%) were in the S + G(2)/M phases of the cell cycle. Stimulation of CXCR3 with I-TAC enhanced thymidine incorporation and cell proliferation and increased p38 and ERK1/2 phosphorylation. These data indicate that 1) human airway epithelial cells primarily express CXCR3-B mRNA, 2) surface expression of CXCR3 is largely confined to the S + G(2)/M phases of the cell cycle, and 3) activation of CXCR3 induces DNA synthesis, cell proliferation, and activation of MAPK pathways. We speculate that activation of CXCR3 exerts a mitogenic effect in HBEC, which may be important during airway mucosal injury in obstructive airway diseases such as asthma and chronic obstructive pulmonary disease.

  6. Differential heat shock response of primary human cell cultures and established cell lines

    DEFF Research Database (Denmark)

    Richter, W W; Issinger, O G

    1986-01-01

    degrees C treatment, whereas in immortalized cell lines usually 90% of the cells were found in suspension. Enhanced expression of the major heat shock protein (hsp 70) was found in all heat-treated cells. In contrast to the primary cell cultures, established and transformed cell lines synthesized...

  7. Antiproliferative effect of isopentenylated coumarins on several cancer cell lines.

    Science.gov (United States)

    Kawaii, S; Tomono, Y; Ogawa, K; Sugiura, M; Yano, M; Yoshizawa, Y; Ito, C; Furukawa, H

    2001-01-01

    33 coumarins, mainly the simple isopentenylated coumarins and derived pyrano- and furanocoumarins, were examined for their antiproliferative activity towards several cancer and normal human cell lines. The pyrano- and furanocoumarins showed strong activity against the cancer cell lines, whereas they had weak antiproliferative activity against the normal human cell lines. The decreasing rank order of potency was osthenone (10), clausarin (25), clausenidin (26), dentatin (24), nordentatin (23), imperatorin (29), seselin (27), xanthyletin (21), suberosin (17), phebalosin (8) and osthol (12). The structure-activity relationship established from the results revealed that the 1,1-dimethylallyl and isopentenyl groups have an important role for antiproliferative activity.

  8. Establishment and characterization of rat portal myofibroblast cell lines.

    Directory of Open Access Journals (Sweden)

    Michel Fausther

    Full Text Available The major sources of scar-forming myofibroblasts during liver fibrosis are activated hepatic stellate cells (HSC and portal fibroblasts (PF. In contrast to well-characterized HSC, PF remain understudied and poorly defined. This is largely due to the facts that isolation of rodent PF for functional studies is technically challenging and that PF cell lines had not been established. To address this, we have generated two polyclonal portal myofibroblast cell lines, RGF and RGF-N2. RGF and RGF-N2 were established from primary PF isolated from adult rat livers that underwent culture activation and subsequent SV40-mediated immortalization. Specifically, Ntpdase2/Cd39l1-sorted primary PF were used to generate the RGF-N2 cell line. Both cell lines were functionally characterized by RT-PCR, immunofluorescence, immunoblot and bromodeoxyuridine-based proliferation assay. First, immortalized RGF and RGF-N2 cells are positive for phenotypic myofibroblast markers alpha smooth muscle actin, type I collagen alpha-1, tissue inhibitor of metalloproteinases-1, PF-specific markers elastin, type XV collagen alpha-1 and Ntpdase2/Cd39l1, and mesenchymal cell marker ecto-5'-nucleotidase/Cd73, while negative for HSC-specific markers desmin and lecithin retinol acyltransferase. Second, both RGF and RGF-N2 cell lines are readily transfectable using standard methods. Finally, RGF and RGF-N2 cells attenuate the growth of Mz-ChA-1 cholangiocarcinoma cells in co-culture, as previously demonstrated for primary PF. Immortalized rat portal myofibroblast RGF and RGF-N2 cell lines express typical markers of activated PF-derived myofibroblasts, are suitable for DNA transfection, and can effectively inhibit cholangiocyte proliferation. Both RGF and RGF-N2 cell lines represent novel in vitro cellular models for the functional studies of portal (myofibroblasts and their contribution to the progression of liver fibrosis.

  9. Molecular Cogs: Interplay between Circadian Clock and Cell Cycle.

    Science.gov (United States)

    Gaucher, Jonathan; Montellier, Emilie; Sassone-Corsi, Paolo

    2018-05-01

    The cell cycle and the circadian clock operate as biological oscillators whose timed functions are tightly regulated. Accumulating evidence illustrates the presence of molecular links between these two oscillators. This mutual interplay utilizes various coupling mechanisms, such as the use of common regulators. The connection between these two cyclic systems has unique interest in the context of aberrant cell proliferation since both of these oscillators are frequently misregulated in cancer cells. Further studies will provide deeper understanding of the detailed molecular connections between the cell cycle and the circadian clock and may also serve as a basis for the design of innovative therapeutic strategies. Copyright © 2018 Elsevier Ltd. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    Koramit Suppipat

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

  11. Combination therapy with vemurafenib (PLX4032/RG7204 and metformin in melanoma cell lines with distinct driver mutations

    Directory of Open Access Journals (Sweden)

    Recio Juan A

    2011-05-01

    Full Text Available Abstract Background A molecular linkage between the MAPK and the LKB1-AMPK energy sensor pathways suggests that combined MAPK oncogene inhibition and metabolic modulation of AMPK would be more effective than either manipulation alone in melanoma cell lines. Materials and methods The combination of the BRAF inhibitor vemurafenib (formerly PLX4032 and metformin were tested against a panel of human melanoma cell lines with defined BRAF and NRAS mutations for effects on viability, cell cycle and apoptosis. Signaling molecules in the MAPK, PI3K-AKT and LKB1-AMPK pathways were studied by Western blot. Results Single agent metformin inhibited proliferation in 12 out of 19 cell lines irrespective of the BRAF mutation status, but in one NRASQ61K mutant cell line it powerfully stimulated cell growth. Synergistic anti-proliferative effects of the combination of metformin with vemurafenib were observed in 6 out of 11 BRAFV600E mutants, including highly synergistic effects in two BRAFV600E mutant melanoma cell lines. Antagonistic effects were noted in some cell lines, in particular in BRAFV600E mutant cell lines resistant to single agent vemurafenib. Seven out of 8 BRAF wild type cell lines showed marginally synergistic anti-proliferative effects with the combination, and one cell line had highly antagonistic effects with the combination. The differential effects were not dependent on the sensitivity to each drug alone, effects on cell cycle or signaling pathways. Conclusions The combination of vemurafenib and metformin tended to have stronger anti-proliferative effects on BRAFV600E mutant cell lines. However, determinants of vemurafenib and metformin synergism or antagonism need to be understood with greater detail before any potential clinical utility of this combination.

  12. A stromal myoid cell line provokes thymic erythropoiesis between ...

    African Journals Online (AJOL)

    Background: The thymus provides an optimal cellular and humoral microenvironment for cell line committed differentiation of haematopoietic stem cells. The immigration process requires the secretion of at least one peptide called thymotaxine by cells of the reticulo-epithelial (RE) network of the thymic stromal cellular ...

  13. Cytotoxicity against MCF-7 breast cancer cell line and interaction ...

    African Journals Online (AJOL)

    N6-furfuryladenine (kinetin) is a cytokinin growth factor with several biological effects observed in human cells and fruit flies. Kinetin exists naturally in the DNA of almost all organisms tested so far, including human cells and various plants. The cytotoxicity effect of kinetin on MCF-7 breast cancer cell lines was measured by ...

  14. Comparative analysis of gene expression in normal and cancer human prostate cell lines

    Directory of Open Access Journals (Sweden)

    E. E. Rosenberg

    2014-04-01

    Full Text Available Prostate cancer is one of the main causes of mortality in men with malignant tumors. The urgent problem was a search for biomarkers of prostate cancer, which would allow distinguishing between aggressive metastatic and latent tumors. The aim of this work was to search for differentially expressed genes in normal epithelial cells PNT2 and prostate cancer cell lines LNCaP, DU145 and PC3, produced from tumors with different aggressiveness and metas­tatic ability. Such genes might be used to create a panel of prognostic markers for aggressiveness and metastasis. Relative gene expression of 65 cancer-related genes was determined by the quantitative polymerase chain reaction (Q-PCR. Expression of 29 genes was changed in LNCaP cells, 20 genes in DU145 and 16 genes in PC3 cell lines, compared with normal line PNT2. The obtained data make it possible to conclude that the epithelial-mesenchymal cell transition took place, which involved the loss of epithelial markers, reduced cell adhesion and increased migration. We have also found few differentially expressed genes among 3 prostate cancer cell lines. We have found that genes, involved in cell adhesion (CDH1, invasiveness and metastasis (IL8, CXCL2 and cell cycle control (P16, CCNE1 underwent most changes. These genes might be used for diagnosis and prognosis of invasive metastatic prostate tumors.

  15. The timing of T cell priming and cycling

    Directory of Open Access Journals (Sweden)

    Reinhard eObst

    2015-11-01

    Full Text Available The proliferation of specific lymphocytes is the central tenet of the clonal selection paradigm. Antigen recognition by T cells triggers a series of events that produces expanded clones of differentiated effector cells. TCR signaling events are detectable within seconds and minutes and are likely to continue for hours and days in vivo. Here, I review the work done on the importance of TCR signals in the later part of the expansion phase of the primary T cell response, primarily regarding the regulation of the cell cycle in CD4+ and CD8+ cells. The results suggest a degree of programming by early signals for effector differentiation, particularly in the CD8+ T cell compartment, with optimal expansion supported by persistent antigen presentation later on. Differences to CD4+ T cell expansion and new avenues towards a molecular understanding of cell cycle regulation in lymphocytes are discussed.

  16. Thermally regenerative hydrogen/oxygen fuel cell power cycles

    Science.gov (United States)

    Morehouse, J. H.

    1986-01-01

    Two innovative thermodynamic power cycles are analytically examined for future engineering feasibility. The power cycles use a hydrogen-oxygen fuel cell for electrical energy production and use the thermal dissociation of water for regeneration of the hydrogen and oxygen. The TDS (thermal dissociation system) uses a thermal energy input at over 2000 K to thermally dissociate the water. The other cycle, the HTE (high temperature electrolyzer) system, dissociates the water using an electrolyzer operating at high temperature (1300 K) which receives its electrical energy from the fuel cell. The primary advantages of these cycles is that they are basically a no moving parts system, thus having the potential for long life and high reliability, and they have the potential for high thermal efficiency. Both cycles are shown to be classical heat engines with ideal efficiency close to Carnot cycle efficiency. The feasibility of constructing actual cycles is investigated by examining process irreversibilities and device efficiencies for the two types of cycles. The results show that while the processes and devices of the 2000 K TDS exceed current technology limits, the high temperature electrolyzer system appears to be a state-of-the-art technology development. The requirements for very high electrolyzer and fuel cell efficiencies are seen as determining the feasbility of the HTE system, and these high efficiency devices are currently being developed. It is concluded that a proof-of-concept HTE system experiment can and should be conducted.

  17. The Dynamical Mechanisms of the Cell Cycle Size Checkpoint

    International Nuclear Information System (INIS)

    Feng Shi-Fu; Yang Ling; Yan Jie; Liu Zeng-Rong

    2012-01-01

    Cell division must be tightly coupled to cell growth in order to maintain cell size, whereas the mechanisms of how initialization of mitosis is regulated by cell size remain to be elucidated. We develop a mathematical model of the cell cycle, which incorporates cell growth to investigate the dynamical properties of the size checkpoint in embryos of Xenopus laevis. We show that the size checkpoint is naturally raised from a saddle-node bifurcation, and in a mutant case, the cell loses its size control ability due to the loss of this saddle-node point

  18. Anti-proliferative effect of 20-hydroxyecdysone in a lepidopteran cell line.

    Science.gov (United States)

    Auzoux-Bordenave, Stéphanie; Hatt, Philippe-Jacques; Porcheron, Patrick

    2002-02-01

    Ecdysteroids are steroid hormones involved in the epidermal growth of arthropods, controlling cell proliferation and further differentiation of target cells. The epidermal cell line IAL-PID2, established from imaginal discs of the Indian meal moth Plodia interpunctella kept its sensitivity to ecdysteroids in vitro, cells being able to respond to them by cytological and biochemical changes. When added to the culture medium, 20-hydroxyecdysone (20E) stopped cell proliferation and induced formation of epithelial-like aggregates. In order to better understand the cellular sequence of ecdysteroids signalling in epidermal cells we used the IAL-PID2 cell line for in vitro investigations of cytological events induced by the moulting hormone. After a 40 h serum deprivation, formazan assay (XTT) was routinely used to evaluate anti-proliferative effects of 20E during cell cycle. We established a more precise timing of the period of cell sensitivity to the hormone during the cell cycle, by the use of the mitotic index and the BrdU incorporation test. These in vitro assays were performed in parallel with the description of some hormone dependant cytological events, using immunofluorescent labelling with anti-beta tubulin/FITC antibodies and DNA staining.

  19. Dual Pressure versus Hybrid Recuperation in an Integrated Solid Oxide Fuel Cell Cycle – Steam Cycle

    DEFF Research Database (Denmark)

    Rokni, Masoud

    2014-01-01

    A SOFC (solid oxide fuel cell) cycle running on natural gas was integrated with a ST (steam turbine) cycle. The fuel is desulfurized and pre-reformed before entering the SOFC. A burner was used to combust the remaining fuel after the SOFC stacks. The off-gases from the burner were used to produce...... pressure configuration steam cycle combined with SOFC cycle (SOFC-ST) was new and has not been studied previously. In each of the configuration, a hybrid recuperator was used to recovery the remaining energy of the off-gases after the HRSG. Thus, four different plants system setups were compared to each...... other to reveal the most superior concept with respect to plant efficiency and power. It was found that in order to increase the plant efficiency considerably, it was enough to use a single pressure with a hybrid recuperator instead of a dual pressure Rankine cycle....

  20. Induction of apoptosis by opium in some tumor cell lines.

    Science.gov (United States)

    Khaleghi, M; Farsinejad, A; Dabiri, S; Asadikaram, G

    2016-09-30

    The current study is aimed at investigation of the opium effects on the apoptosis of different cell lines in culture medium and compares such effects with one another. The study is carried out on over 8 cell lines (AA8, AGS, Hela, HepG2, MCF7, N2a, PC12, WEHI). A 2.86 x 10-4 g/ml opium concentration was prepared and added to the culture medium of the cell lines for 48 hours. Cytotoxicity was tested by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay. The apoptotic effect of opium on the cell lines was analyzed by Annexin-PI test. Opium with concentration of 2.86 x 10-4 g/ml in 48 hours significantly induces apoptosis in certain cell lines (i.e. AA8, N2a, WEHI), apoptosis and necrosis in some others (i.e. Hela, HepG2, MCF7, and PC12), and also solely necrosis in the AGS cell line. One could infer that the usage of opium with different levels in different tissues leads to certain disorders in some tissues and may have therapeutic effects under distinctive conditions (i.e. unchecked growth of cells) as confirmed by the results.

  1. HIV-1 Vif's Capacity To Manipulate the Cell Cycle Is Species Specific.

    Science.gov (United States)

    Evans, Edward L; Becker, Jordan T; Fricke, Stephanie L; Patel, Kishan; Sherer, Nathan M

    2018-04-01

    Cells derived from mice and other rodents exhibit profound blocks to HIV-1 virion production, reflecting species-specific incompatibilities between viral Tat and Rev proteins and essential host factors cyclin T1 (CCNT1) and exportin-1 (XPO1, also known as CRM1), respectively. To determine if mouse cell blocks other than CCNT1 and XPO1 affect HIV's postintegration stages, we studied HIV-1 NL4-3 gene expression in mouse NIH 3T3 cells modified to constitutively express HIV-1-compatible versions of CCNT1 and XPO1 (3T3.CX cells). 3T3.CX cells supported both Rev-independent and Rev-dependent viral gene expression and produced relatively robust levels of virus particles, confirming that CCNT1 and XPO1 represent the predominant blocks to these stages. Unexpectedly, however, 3T3.CX cells were remarkably resistant to virus-induced cytopathic effects observed in human cell lines, which we mapped to the viral protein Vif and its apparent species-specific capacity to induce G 2 /M cell cycle arrest. Vif was able to mediate rapid degradation of human APOBEC3G and the PPP2R5D regulatory B56 subunit of the PP2A phosphatase holoenzyme in mouse cells, thus demonstrating that Vif NL4-3 's modulation of the cell cycle can be functionally uncoupled from some of its other defined roles in CUL5-dependent protein degradation. Vif was also unable to induce G 2 /M cell cycle arrest in other nonhuman cell types, including cells derived from nonhuman primates, leading us to propose that one or more human-specific cofactors underpin Vif's ability to modulate the cell cycle. IMPORTANCE Cells derived from mice and other rodents exhibit profound blocks to HIV-1 replication, thus hindering the development of a low-cost small-animal model for studying HIV/AIDS. Here, we engineered otherwise-nonpermissive mouse cells to express HIV-1-compatible versions of two species-specific host dependency factors, cyclin T1 (CCNT1) and exportin-1 (XPO1) (3T3.CX cells). We show that 3T3.CX cells rescue HIV-1

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

    Directory of Open Access Journals (Sweden)

    Minjun Wu

    Full Text Available 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.

  3. Metformin inhibits cell cycle progression of B-cell chronic lymphocytic leukemia cells.

    Science.gov (United States)

    Bruno, Silvia; Ledda, Bernardetta; Tenca, Claudya; Ravera, Silvia; Orengo, Anna Maria; Mazzarello, Andrea Nicola; Pesenti, Elisa; Casciaro, Salvatore; Racchi, Omar; Ghiotto, Fabio; Marini, Cecilia; Sambuceti, Gianmario; DeCensi, Andrea; Fais, Franco

    2015-09-08

    B-cell chronic lymphocytic leukemia (CLL) was believed to result from clonal accumulation of resting apoptosis-resistant malignant B lymphocytes. However, it became increasingly clear that CLL cells undergo, during their life, iterative cycles of re-activation and subsequent clonal expansion. Drugs interfering with CLL cell cycle entry would be greatly beneficial in the treatment of this disease. 1, 1-Dimethylbiguanide hydrochloride (metformin), the most widely prescribed oral hypoglycemic agent, inexpensive and well tolerated, has recently received increased attention for its potential antitumor activity. We wondered whether metformin has apoptotic and anti-proliferative activity on leukemic cells derived from CLL patients. Metformin was administered in vitro either to quiescent cells or during CLL cell activation stimuli, provided by classical co-culturing with CD40L-expressing fibroblasts. At doses that were totally ineffective on normal lymphocytes, metformin induced apoptosis of quiescent CLL cells and inhibition of cell cycle entry when CLL were stimulated by CD40-CD40L ligation. This cytostatic effect was accompanied by decreased expression of survival- and proliferation-associated proteins, inhibition of signaling pathways involved in CLL disease progression and decreased intracellular glucose available for glycolysis. In drug combination experiments, metformin lowered the apoptotic threshold and potentiated the cytotoxic effects of classical and novel antitumor molecules. Our results indicate that, while CLL cells after stimulation are in the process of building their full survival and cycling armamentarium, the presence of metformin affects this process.

  4. Lining cells on normal human vertebral bone surfaces

    International Nuclear Information System (INIS)

    Henning, C.B.; Lloyd, E.L.

    1982-01-01

    Thoracic vertebrae from two individuals with no bone disease were studied with the electron microscope to determine cell morphology in relation to bone mineral. The work was undertaken to determine if cell morphology or spatial relationships between the bone lining cells and bone mineral could account for the relative infrequency of bone tumors which arise at this site following radium intake, when compared with other sites, such as the head of the femur. Cells lining the vertebral mineral were found to be generally rounded in appearance with varied numbers of cytoplasmic granules, and they appeared to have a high density per unit of surface area. These features contrasted with the single layer of flattened cells characteristic of the bone lining cells of the femur. A tentative discussion of the reasons for the relative infrequency of tumors in the vertebrae following radium acquisition is presented

  5. Cell cycles and proliferation patterns in Haematococcus pluvialis

    Science.gov (United States)

    Zhang, Chunhui; Liu, Jianguo; Zhang, Litao

    2017-09-01

    Most studies on Haematococcus pluvialis have been focused on cell growth and astaxanthin accumulation; far less attention has been paid to cell cycles and proliferation patterns. The purpose of this study was to clarify cell cycles and proliferation patterns in H. pluvialis microscopically using a camera and video recorder system. The complicated life history of H. pluvialis can be divided into two stages: the motile stage and the non-motile stage. All the cells can be classified into forms as follows: motile cell, nonmotile cell, zoospore and aplanospore. The main cell proliferation, both in the motile phase and non-motile phase in H. pluvialis, is by asexual reproduction. Under normal growth conditions, a motile cell usually produces two, sometimes four, and exceptionally eight zoospores. Under unfavorable conditions, the motile cell loses its flagella and transforms into a non-motile cell, and the non-motile cell usually produces 2, 4 or 8 aplanospores, and occasionally 20-32 aplanospores, which further develop into non-motile cells. Under suitable conditions, the non-motile cell is also able to release zoospores. The larger non-motile cells produce more than 16 zoospores, and the smaller ones produce 4 or 8 zoospores. Vegetative reproduction is by direct cell division in the motile phase and by occasional cell budding in the non-motile phase. There is, as yet, no convincing direct evidence for sexual reproduction.

  6. DNA fingerprinting of the NCI-60 cell line panel.

    Science.gov (United States)

    Lorenzi, Philip L; Reinhold, William C; Varma, Sudhir; Hutchinson, Amy A; Pommier, Yves; Chanock, Stephen J; Weinstein, John N

    2009-04-01

    The National Cancer Institute's NCI-60 cell line panel, the most extensively characterized set of cells in existence and a public resource, is frequently used as a screening tool for drug discovery. Because many laboratories around the world rely on data from the NCI-60 cells, confirmation of their genetic identities represents an essential step in validating results from them. Given the consequences of cell line contamination or misidentification, quality control measures should routinely include DNA fingerprinting. We have, therefore, used standard DNA microsatellite short tandem repeats to profile the NCI-60, and the resulting DNA fingerprints are provided here as a reference. Consistent with previous reports, the fingerprints suggest that several NCI-60 lines have common origins: the melanoma lines MDA-MB-435, MDA-N, and M14; the central nervous system lines U251 and SNB-19; the ovarian lines OVCAR-8 and OVCAR-8/ADR (also called NCI/ADR); and the prostate lines DU-145, DU-145 (ATCC), and RC0.1. Those lines also show that the ability to connect two fingerprints to the same origin is not affected by stable transfection or by the development of multidrug resistance. As expected, DNA fingerprints were not able to distinguish different tissues-of-origin. The fingerprints serve principally as a barcodes.

  7. Plant Characteristics of an Integrated Solid Oxide Fuel Cell Cycle and a Steam Cycle

    DEFF Research Database (Denmark)

    Rokni, Masoud

    2010-01-01

    Plant characteristics of a system containing a solid oxide fuel cell (SOFC) cycle on the top of a Rankine cycle were investigated. Natural gas (NG) was used as the fuel for the plant. A desulfurization reactor removes the sulfur content in the fuel, while a pre-reformer broke down the heavier...... recovery steam generator (HRSG). The remaining energy of the off-gases was recycled back to the topping cycle for further utilization. Several parameter studies were carried out to investigate the sensitivity of the suggested plant. It was shown that the operation temperature of the desulfurization unit...

  8. Effects of valproic acid and pioglitazone on cell cycle progression and proliferation of T-cell acute lymphoblastic leukemia Jurkat cells

    Directory of Open Access Journals (Sweden)

    Marie Saghaeian Jazi

    2016-07-01

    Full Text Available Objective(s: T-cell acute lymphoblastic leukemia (T-ALL is an aggressive hematologic malignant tumor. Administration of chemical compounds influencing apoptosis and T cell development has been discussed as promising novel therapeutic strategies. Valproic acid (VPA as a recently emerged anti-neoplastic histone deacetylase (HDAC inhibitor and pioglitazone (PGZ as a high-affinity peroxisome proliferator-activated receptor-gamma (PPARγ agonist have been shown to induce apoptosis and cell cycle arrest in different studies. Here, we aimed to investigate the underlying molecular mechanisms involved in anti-proliferative effects of these compounds on human Jurkat cells. Materials and Methods: Treated cells were evaluated for cell cycle progression and apoptosis using flowcytometry and MTT viability assay. Real-time RT-PCR was carried out to measure the alterations in key genes associated with cell death and cell cycle arrest. Results: Our findings illustrated that both VPA and PGZ can inhibit Jurkat E6.1 cells in vitro after   24 hr; however, PGZ 400 μM presents the most anti-proliferative effect. Interestingly, treated cells have been arrested in G2/M with deregulated cell division cycle 25A (Cdc25A phosphatase and cyclin-dependent kinase inhibitor 1B (CDKN1B or p27 expression. Expression of cyclin D1 gene was inhibited when DNA synthesis entry was declined. Cell cycle deregulation in PGZ and VPA-exposed cells generated an increase in the proportion of aneuploid cell population, which has not reported before. Conclusion: These findings define that anti-proliferative effects of PGZ and VPA on Jurkat cell line are mediated by cell cycle deregulation. Thus, we suggest PGZ and VPA may relieve potential therapeutic application against apoptosis-resistant malignancies.

  9. Application of DNA fingerprints for cell-line individualization.

    OpenAIRE

    Gilbert, D A; Reid, Y A; Gail, M H; Pee, D; White, C; Hay, R J; O'Brien, S J

    1990-01-01

    DNA fingerprints of 46 human cell lines were derived using minisatellite probes for hypervariable genetic loci. The incidence of 121 HaeIII DNA fragments among 33 cell lines derived from unrelated individuals was used to estimate allelic and genotypic frequencies for each fragment and for composite individual DNA fingerprints. We present a quantitative estimate of the extent of genetic difference between individuals, an estimate based on the percentage of restriction fragments at which they d...

  10. Establishment of cell lines from adult T-cell leukemia cells dependent on negatively charged polymers.

    Science.gov (United States)

    Kagami, Yoshitoyo; Uchiyama, Susumu; Kato, Harumi; Okada, Yasutaka; Seto, Masao; Kinoshita, Tomohiro

    2017-07-05

    Growing adult T-cell leukemia/lymphoma (ATLL) cells in vitro is difficult. Here, we examined the effects of static electricity in the culture medium on the proliferation of ATLL cells. Six out of 10 ATLL cells did not proliferate in vitro and thus had to be cultured in a medium containing negatively charged polymers. In the presence of poly-γ-glutamic acid (PGA) or chondroitin sulfate (CDR), cell lines (HKOX3-PGA, HKOX3-CDR) were established from the same single ATLL case using interleukin (IL)-2, IL-4, and feeder cells expressing OX40L (OX40L + HK). Dextran sulfate inhibited growth in both HKOX3 cell lines. Both PGA and OX40L + HK were indispensable for HKOX3-PGA growth, but HKOX3-CDR could proliferate in the presence of CDR or OX40L + HK alone. Thus, the specific action of each negatively charged polymer promoted the growth of specific ATLL cells in vitro.

  11. Isolation of two chloroethylnitrosourea-sensitive Chinese hamster cell lines

    International Nuclear Information System (INIS)

    Hata, H.; Numata, M.; Tohda, H.; Yasui, A.; Oikawa, A.

    1991-01-01

    1-[(4-Amino-2-methylpyrimidin-5-yl)methyl]-3-(2-chloroethyl)-3- nitrosourea hydrochloride (ACNU), a cancer chemotherapeutic bifunctional alkylating agent, causes chloroethylation of DNA and subsequent DNA strand cross-linking through an ethylene bridge. We isolated and characterized two ACNU-sensitive mutants from mutagenized Chinese hamster ovary cells and found them to be new drug-sensitive recessive Chinese hamster mutants. Both mutants were sensitive to various monofunctional alkylating agents in a way similar to that of the parental cell lines CHO9. One mutant (UVS1) was cross-sensitive to UV and complemented the UV sensitivity of all Chinese hamster cell lines of 7 established complementation groups. Since UV-induced unscheduled DNA synthesis was very low, a new locus related to excision repair is thought to be defective in this cell line. Another ACNU-sensitive mutant, CNU1, was slightly more sensitive to UV than the parent cell line. CNU1 was cross-sensitive to 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea and slightly more sensitive to mitomycin C. No increased accumulation of ACNU and a low level of UV-induced unscheduled DNA synthesis in this cell as compared with the parental cell line suggest that there is abnormality in a repair response of this mutant cell to some types of DNA cross-links

  12. In vitro Rb-1 gene transfer to retinoblastoma cell lines

    International Nuclear Information System (INIS)

    Choi, Sang Wook; Ham, Yong Hoh; Kim, Mee Heui

    1994-04-01

    After transfection of Rb-vector to packaging cell line (CRIP) by Ca-P precipitation method, we could select nineteen colonies of G-418 resistant clone by ring cloning. Each colony was transduced to NIH3T3 cells to select the one which produces high titer virus. After NIH3T3 cells transduction, we could get 28 colony counts for the high, 127 for the middle, and 6 for the low viral titer. With the supernatant of the high viral titer colony (CRIPRb 2-5). We transduct retinoblastoma cell lines. 5 figs, 11 refs. (Author)

  13. The cell cycle-regulated genes of Schizosaccharomyces pombe.

    Science.gov (United States)

    Oliva, Anna; Rosebrock, Adam; Ferrezuelo, Francisco; Pyne, Saumyadipta; Chen, Haiying; Skiena, Steve; Futcher, Bruce; Leatherwood, Janet

    2005-07-01

    Many genes are regulated as an innate part of the eukaryotic cell cycle, and a complex transcriptional network helps enable the cyclic behavior of dividing cells. This transcriptional network has been studied in Saccharomyces cerevisiae (budding yeast) and elsewhere. To provide more perspective on these regulatory mechanisms, we have used microarrays to measure gene expression through the cell cycle of Schizosaccharomyces pombe (fission yeast). The 750 genes with the most significant oscillations were identified and analyzed. There were two broad waves of cell cycle transcription, one in early/mid G2 phase, and the other near the G2/M transition. The early/mid G2 wave included many genes involved in ribosome biogenesis, possibly explaining the cell cycle oscillation in protein synthesis in S. pombe. The G2/M wave included at least three distinctly regulated clusters of genes: one large cluster including mitosis, mitotic exit, and cell separation functions, one small cluster dedicated to DNA replication, and another small cluster dedicated to cytokinesis and division. S. pombe cell cycle genes have relatively long, complex promoters containing groups of multiple DNA sequence motifs, often of two, three, or more different kinds. Many of the genes, transcription factors, and regulatory mechanisms are conserved between S. pombe and S. cerevisiae. Finally, we found preliminary evidence for a nearly genome-wide oscillation in gene expression: 2,000 or more genes undergo slight oscillations in expression as a function of the cell cycle, although whether this is adaptive, or incidental to other events in the cell, such as chromatin condensation, we do not know.

  14. The cell cycle-regulated genes of Schizosaccharomyces pombe.

    Directory of Open Access Journals (Sweden)

    Anna Oliva

    2005-07-01

    Full Text Available Many genes are regulated as an innate part of the eukaryotic cell cycle, and a complex transcriptional network helps enable the cyclic behavior of dividing cells. This transcriptional network has been studied in Saccharomyces cerevisiae (budding yeast and elsewhere. To provide more perspective on these regulatory mechanisms, we have used microarrays to measure gene expression through the cell cycle of Schizosaccharomyces pombe (fission yeast. The 750 genes with the most significant oscillations were identified and analyzed. There were two broad waves of cell cycle transcription, one in early/mid G2 phase, and the other near the G2/M transition. The early/mid G2 wave included many genes involved in ribosome biogenesis, possibly explaining the cell cycle oscillation in protein synthesis in S. pombe. The G2/M wave included at least three distinctly regulated clusters of genes: one large cluster including mitosis, mitotic exit, and cell separation functions, one small cluster dedicated to DNA replication, and another small cluster dedicated to cytokinesis and division. S. pombe cell cycle genes have relatively long, complex promoters containing groups of multiple DNA sequence motifs, often of two, three, or more different kinds. Many of the genes, transcription factors, and regulatory mechanisms are conserved between S. pombe and S. cerevisiae. Finally, we found preliminary evidence for a nearly genome-wide oscillation in gene expression: 2,000 or more genes undergo slight oscillations in expression as a function of the cell cycle, although whether this is adaptive, or incidental to other events in the cell, such as chromatin condensation, we do not know.

  15. Development of 700 pps high-duty-cycle line-type pulse modulator

    Energy Technology Data Exchange (ETDEWEB)

    Baba, H.; Satoh, K.; Miura, A. [NIHON KOSHUHA Co., LTD., Yokohama, Kanagawa (Japan)] [and others

    1997-04-01

    The high-duty-cycle line-type pulse modulator has been developed to drive the 5.5 MW S-band klystron at the 700 pps maximum repetition-rate and the 14 {mu}sec flat-top pulse-width. To keep an enough recovery time to the thyratron-tube, the command charging scheme was adopted. To do this, a charging SCR-bank has been developed, which is capable of handling the peak charging current of 50 A. The system achieved the world wide highest average output-power of 205 kW. Two modulators have been installed in a new high-duty-cycle electron linear accelerator, which has been started its business operation in March 1996 as an electron-beam-sterilization facility. (J.P.N)

  16. Advanced power cycling test for power module with on-line on-state VCE measurement

    DEFF Research Database (Denmark)

    Choi, Ui-min; Trintis, Ionut; Blaabjerg, Frede

    2015-01-01

    module. The proposed concept can perform various stress conditions which is valid in a real mission profile and it is using a real power converter application with small loss. The concept of the proposed test setup is first presented. Then, the on-line on-state collector-emitter voltage VCE measurement......Recent research has made an effort to improve the reliability of power electronic systems to comply with more stringent constraints on cost, safety, predicted lifetime and availability in many applications. For this, studies about failure mechanisms of power electronic components and lifetime...... estimation of power semiconductor devices and capacitors have been done. Accelerated power cycling test is one of the common tests to assess the power device module and develop the lifetime model considering the physics of failure. In this paper, a new advanced power cycling test setup is proposed for power...

  17. Effect of repeated irradiation on biological characteristics of lung adenocarcinoma cell line Anip973 in vitro

    International Nuclear Information System (INIS)

    Xu Qingyong; Xu Xiangying; Yang Zhiwei

    2008-01-01

    Objective: To study the effect of repeated irradiation on biological characteristics of human lung adenocarcinoma cell line Anip973 in vitro. Methods: Anip973 cells were treated with high energy X-ray to a total dose of 60 Gy at 4 Gy fractions. The radiosensitivity of Anip973R and its parental cell were measured by clonogenic assay. The biological parameters were fitted to the single hit multitarget formula. Furthermore, the population double time(PDT) and cell cycle distribution were measured by cell growth curve and flow cytometry, respectively. Results: Comparing with its parental cell, Anip973 R acquired radioresistance showing increased D 0 , D q and SF 2 and a broader shoulder. PDT of Anip973R extended 3 h more than that of Anip973. The Anip973R also showed higher and lower percentage of cells in G 1 and S phase (P 2 /M distribution (P>0.05). Conclusions: A radioresistant lung adenocarcinoma cell line Anip973R is established by repeatedly irradiation. Its radioresistance displays obviously in lower dose area. However, its characteristic of cell cycle is not completely coincident with the classical radiobiological theory. (authors)

  18. Neurosecretory cells of the amygdaloid complex during estrous cycle.

    Science.gov (United States)

    Akhmadeev, A V; Kalimullina, L B

    2005-02-01

    Ultrastructure of neurosecretory cells of the dorsomedial nucleus of the cerebral amygdaloid complex (one of the main zones of sexual dimorphism) was studied in different phases of the estrous cycle. The characteristics of the "light" and "dark" cells change depending on the concentrations of sex steroids during estrus and metestrus.

  19. Establishment and characterization of a novel osteosarcoma cell line: CHOS.

    Science.gov (United States)

    Liu, Yunlu; Feng, Xiaobo; Zhang, Yukun; Jiang, Hongyan; Cai, Xianyi; Yan, Xinxin; Huang, Zengfa; Mo, Fengbo; Yang, Wen; Yang, Cao; Yang, Shuhua; Liu, Xianzhe

    2016-12-01

    Osteosarcoma has a well-recognized bimodal distribution, with the first peak in adolescence and another in the elderly age-group. The elderly patients have different clinical features and a poorer prognosis as compared to adolescents. To better understand the biological features of osteosarcoma in the elderly population, we established a new human osteosarcoma cell line from a 58-year-old man with primary chondroblastic osteosarcoma. After 6 months of continuous culture in vitro for over 50 passages, an immortalized cell line CHOS was established. The cell line was well-characterized by cytogenetic, biomarker, functional, and histological analyses. The CHOS cells exhibited a spindle-shaped morphology and a doubling time of 36 h. Cytogenetic analysis of CHOS cells revealed the loss of chromosome Y and the gain of chromosome 12. Quantitative real-time polymerase chain reaction (RT-PCR), Western blotting and/or immunofluorescence revealed the expression of chondroblastic, mesenchymal and tumor metastasis markers in the CHOS cells. Compared with the osteosarcoma cell line, the CHOS cells were found to be more sensitive to cisplatin and doxorubicin, but were resistant to methotrexate. The cell line was highly tumorigenic and maintained the histological characteristics and invasive nature of the original tumor. Furthermore, on immunohistochemical analysis, the xenografts and metastases were found to co-express collagen II, aggrecan, vimentin and S100A4 that resembled the original tumor cells. Our results indicate, the potential of CHOS cell line to serve as a useful tool for further studies on the molecular biology of osteosarcoma, especially in the elderly patients. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:2116-2125, 2016. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  20. Membrane lipidome of an epithelial cell line

    DEFF Research Database (Denmark)

    Sampaio, Julio L; Gerl, Mathias J; Klose, Christian

    2011-01-01

    Tissue differentiation is an important process that involves major cellular membrane remodeling. We used Madin-Darby canine kidney cells as a model for epithelium formation and investigated the remodeling of the total cell membrane lipidome during the transition from a nonpolarized morphology...... to an epithelial morphology and vice versa. To achieve this, we developed a shotgun-based lipidomics workflow that enabled the absolute quantification of mammalian membrane lipidomes with minimal sample processing from low sample amounts. Epithelial morphogenesis was accompanied by a major shift from sphingomyelin...... to generate an apical membrane domain that serves as a protective barrier for the epithelial sheet....

  1. Sulforaphane enhances irradiation effects in terms of perturbed cell cycle progression and increased DNA damage in pancreatic cancer cells.

    Directory of Open Access Journals (Sweden)

    Patrick Naumann

    Full Text Available Sulforaphane (SFN, an herbal isothiocyanate enriched in cruciferous vegetables like broccoli and cauliflower, has gained popularity for its antitumor effects in cell lines such as pancreatic cancer. Antiproliferative as well as radiosensitizing properties were reported for head and neck cancer but little is known about its effects in pancreatic cancer cells in combination with irradiation (RT.In four established pancreatic cancer cell lines we investigated clonogenic survival, analyzed cell cycle distribution and compared DNA damage via flow cytometry and western blot after treatment with SFN and RT.Both SFN and RT show a strong and dose dependent survival reduction in clonogenic assays, an induction of a G2/M cell cycle arrest and an increase in γH2AX protein level indicating DNA damage. Effects were more pronounced in combined treatment and both cell cycle perturbation and DNA damage persisted for a longer period than after SFN or RT alone. Moreover, SFN induced a loss of DNA repair proteins Ku 70, Ku 80 and XRCC4.Our results suggest that combination of SFN and RT exerts a more distinct DNA damage and growth inhibition than each treatment alone. SFN seems to be a viable option to improve treatment efficacy of chemoradiation with hopefully higher rates of secondary resectability after neoadjuvant treatment for pancreatic cancer.

  2. Cell cycle sibling rivalry: Cdc2 vs. Cdk2.

    Science.gov (United States)

    Kaldis, Philipp; Aleem, Eiman

    2005-11-01

    It has been long believed that the cyclin-dependent kinase 2 (Cdk2) binds to cyclin E or cyclin A and exclusively promotes the G1/S phase transition and that Cdc2/cyclin B complexes play a major role in mitosis. We now provide evidence that Cdc2 binds to cyclin E (in addition to cyclin A and B) and is able to promote the G1/S transition. This new concept indicates that both Cdk2 and/or Cdc2 can drive cells through G1/S phase in parallel. In this review we discuss the classic cell cycle model and how results from knockout mice provide new evidence that refute this model. We focus on the roles of Cdc2 and p27 in regulating the mammalian cell cycle and propose a new model for cell cycle regulation that accommodates these novel findings.

  3. Flow downstream of the heliospheric terminal shock: Magnetic field line topology and solar cycle imprint

    Science.gov (United States)

    Nerney, Steven; Suess, S. T.; Schmahl, E. J.

    1995-01-01

    The topology of the magnetic field in the heliosheath is illustrated using plots of the field lines. It is shown that the Archimedean spiral inside the terminal shock is rotated back in the heliosheath into nested spirals that are advected in the direction of the interstellar wind. The 22-year solar magnetic cycle is imprinted onto these field lines in the form of unipolar magnetic envelopes surrounded by volumes of strongly mixed polarity. Each envelope is defined by the changing tilt of the heliospheric current sheet, which is in turn defined by the boundary of unipolar high-latitude regions on the Sun that shrink to the pole at solar maximum and expand to the equator at solar minimum. The detailed shape of the envelopes is regulated by the solar wind velocity structure in the heliosheath.

  4. Effect of magnetic nanoparticles on apoptosis and cell cycle induced by wogonin in Raji cells

    Directory of Open Access Journals (Sweden)

    Wang XM

    2012-02-01

    Full Text Available Lei Wang1,2,*, Haijun Zhang1,2,*, Baoan Chen1,2, Guohua Xia1,2, Shuai Wang1,2, Jian Cheng1,2, Zeye Shao1,2, Chong Gao1,2, Wen Bao1,2, Liang Tian1,2, Yanyan Ren1,2, Peipei Xu1,2, Xiaohui Cai1,2, Ran Liu1,2, Xuemei Wang3 1Department of Hematology and Oncology, Zhongda Hospital, Medical School, 2Faculty of Oncology, Medical School, 3State Key Laboratory of Bioelectronics (Chien-Shiung Wu Laboratory, Southeast University, Nanjing, China*These authors contributed equally to this workAbstract: Traditional Chinese medicine is gradually becoming a new source of anticancer drugs. One such example is wogonin, which is cytotoxic to various cancer cell lines in vitro. However, due to its low water solubility, wogonin is restricted to clinical administration. Recently, the application of drug-coated magnetic nanoparticles (MNPs to increase water solubility of the drug and to enhance its chemotherapeutic efficiency has attracted much attention. In this study, wogonin was conjugated with the drug delivery system of MNPs by mechanical absorption polymerization to fabricate wogonin-loaded MNPs. It was demonstrated that MNPs could strengthen wogonin-induced cell inhibition, apoptosis, and cell cycle arrest in Raji cells by methylthiazol tetrazolium assay, flow cytometer assay, and nuclear 4',6-diamidino-2-phenylindole staining. Furthermore, the molecular mechanisms of these phenomena were explored by western blot, in which the protein levels of caspase 8 and caspase 3 were increased significantly while those of survivin and cyclin E were decreased significantly in wogonin-MNPs group. These findings suggest that the combination of wogonin and MNPs provides a promising strategy for lymphoma therapy.Keywords: wogonin, magnetic nanoparticles, Raji cell, apoptosis, cell cycle, caspase 8, caspase 3, survivin, cyclin E

  5. Caspase Activation and Aberrant Cell Growth in a p53+/+ Cell Line from a Li-Fraumeni Syndrome Family

    Directory of Open Access Journals (Sweden)

    Zaki A. Sherif

    2015-01-01

    Full Text Available Wild-type p53 is well known to induce cell cycle arrest and apoptosis to block aberrant cell growth. However, p53’s unique role in apoptosis and cell proliferation in Li-Fraumeni Syndrome (LFS has not been well elucidated. The aim of this study is to characterize the activity of wild-type p53 protein in LFS family dominated by a germline negative mutant p53. As expected, etoposide-treated wild-type p53-containing cell lines, LFS 2852 and control Jurkat, showed a greater rate of caspase- and annexin V-induced apoptotic cell death compared to the p53-mutant LFS 2673 cell line although mitochondrial and nuclear assays could not detect apoptosis in these organelles. The most intriguing part of the observation was the abnormal proliferation rate of the wild-type p53-containing cell line, which grew twice as fast as 2673 and Jurkat cells. This is important because apoptosis inducers acting through the mitochondrial death pathway are emerging as promising drugs against tumors where the role of p53 is not only to target gene regulation but also to block cell proliferation. This study casts a long shadow on the possible dysregulation of p53 mediators that enable cell proliferation. The deregulation of proliferation pathways represents an important anticancer therapeutic strategy for patients with the LFS phenotype.

  6. Iodine-131 treatment of thyroid cancer cells leads to suppression of cell proliferation followed by induction of cell apoptosis and cell cycle arrest by regulation of B-cell translocation gene 2-mediated JNK/NF-κB pathways

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, L.M.; Pang, A.X., E-mail: zhaoliming515@126.com [Department of Nuclear Medicine, Linyi People' s Hospital, Linyi (China); Department of Urology, Linyi People' s Hospital, Linyi (China)

    2017-10-01

    Iodine-131 ({sup 131}I) is widely used for the treatment of thyroid-related diseases. This study aimed to investigate the expression of p53 and BTG2 genes following {sup 131}I therapy in thyroid cancer cell line SW579 and the possible underlying mechanism. SW579 human thyroid squamous carcinoma cells were cultured and treated with {sup 131}I. They were then assessed for {sup 131}I uptake, cell viability, apoptosis, cell cycle arrest, p53 expression, and BTG2 gene expression. SW579 cells were transfected with BTG2 siRNA, p53 siRNA and siNC and were then examined for the same aforementioned parameters. When treated with a JNK inhibitor of SP600125 and {sup 131}I or with a NF-kB inhibitor of BMS-345541 and {sup 131}I, non-transfected SW579 cells were assessed in JNK/NFkB pathways. It was observed that {sup 131}I significantly inhibited cell proliferation, promoted cell apoptosis and cell cycle arrest. Both BTG2 and p53 expression were enhanced in a dose-dependent manner. An increase in cell viability by up-regulation in Bcl2 gene, a decrease in apoptosis by enhanced CDK2 gene expression and a decrease in cell cycle arrest at G{sub 0}/G{sub 1} phase were also observed in SW579 cell lines transfected with silenced BTG2 gene. When treated with SP600125 and {sup 131}I, the non transfected SW579 cell lines significantly inhibited JNK pathway, NF-kB pathway and the expression of BTG2. However, when treated with BMS-345541 and {sup 131}I, only the NF-kB pathway was suppressed. {sup 131}I suppressed cell proliferation, induced cell apoptosis, and promoted cell cycle arrest of thyroid cancer cells by up-regulating B-cell translocation gene 2-mediated activation of JNK/NF--κB pathways. (author)

  7. REDUCTION OF CYCLE TIME IN SCREW AIR COMPRESSOR ASSEMBLY LINE USING KAIZEN SURVEY

    Directory of Open Access Journals (Sweden)

    D. Rajenthirakumar

    2015-12-01

    Full Text Available In this competitive world, any company has to fulfill its customer needs to survive in the market. Lean manufacturing is a technique that can be adopted in a company to improve the quality of its products, reduce the cost of the production and also deliver the products in less time. The goal of this work is to show the applicability of lean manufacturing’s body of knowledge in a screw air compressor manufacturing company. Here, the main objective is to evolve and test several methodologies to eliminate wastes in the assembly line as the company at present unable to meet the customer demand. A systematic approach is suggested for the implementation of lean principles to showcase that lean could be applied to the compressor assembly line to enhance the productivity thereby making the line more efficient. In the current assembly line there was no work standardization followed by absence of kaizen that has led to an increased assembly time. Thus with the help of lean tools and techniques such as 5S, kaizen, standardization, visual management, poke yoke and string diagram the total cycle time has been reduced from 236 to 209 minutes. This reduction has benefitted the company in meeting the customer demand, increased profit and work satisfaction.

  8. Establishment of human papillomavirus infection requires cell cycle progression.

    Directory of Open Access Journals (Sweden)

    Dohun Pyeon

    2009-02-01

    Full Text Available Human papillomaviruses (HPVs are DNA viruses associated with major human cancers. As such there is a strong interest in developing new means, such as vaccines and microbicides, to prevent HPV infections. Developing the latter requires a better understanding of the infectious life cycle of HPVs. The HPV infectious life cycle is closely linked to the differentiation state of the stratified epithelium it infects, with progeny virus only made in the terminally differentiating suprabasal compartment. It has long been recognized that HPV must first establish its infection within the basal layer of stratified epithelium, but why this is the case has not been understood. In part this restriction might reflect specificity of expression of entry receptors. However, this hypothesis could not fully explain the differentiation restriction of HPV infection, since many cell types can be infected with HPVs in monolayer cell culture. Here, we used chemical biology approaches to reveal that cell cycle progression through mitosis is critical for HPV infection. Using infectious HPV16 particles containing the intact viral genome, G1-synchronized human keratinocytes as hosts, and early viral gene expression as a readout for infection, we learned that the recipient cell must enter M phase (mitosis for HPV infection to take place. Late M phase inhibitors had no effect on infection, whereas G1, S, G2, and early M phase cell cycle inhibitors efficiently prevented infection. We conclude that host cells need to pass through early prophase for successful onset of transcription of the HPV encapsidated genes. These findings provide one reason why HPVs initially establish infections in the basal compartment of stratified epithelia. Only this compartment of the epithelium contains cells progressing through the cell cycle, and therefore it is only in these cells that HPVs can establish their infection. By defining a major condition for cell susceptibility to HPV infection, these

  9. Selection of radioresistant cells by vitamin A deficiency in a small cell lung cancer cell line

    International Nuclear Information System (INIS)

    Terasaki, Takeo; Shimosato, Yukio; Wada, Makio; Yokota, Jun; Terada, Masaaki

    1990-01-01

    Radiation sensitivity of a human small cell lung cancer cell line, Lu-134-B cells, cultured in serum-supplemented medium and of cells transferred to and cultured in delipidized serum-supplemented (vitamin A-deficient) medium was studied. The cells cultured in serum-supplemented medium showed the phenotype of classic small cell lung cancer sensitive to radiation, while cells transferred to delipidized serum-supplemented medium showed partial squamous cell differentiation and became resistant to radiation. These results suggest that some small cell lung cancer cells in vitro change their morphology and radiosensitivity depending on the culture conditions. The change in radiosensitivity was reproducible, and was not reversible by culture of the radioresistant cells in delipidized serum-supplemented medium with addition of retinoic acid (vitamin A-sufficient medium) for two months, although squamous cells disappeared. Acquisition of radioresistancy was considered to occur as the result of clonal selective growth in delipidized medium of a minor cell population in the original cell culture, based on a study of chromosome number. It was also found that there was no association of myc-family oncogenes with the changes of radiosensitivity in this cell line. (author)

  10. Cell Division, a new open access online forum for and from the cell cycle community

    Directory of Open Access Journals (Sweden)

    Kaldis Philipp

    2006-04-01

    Full Text Available Abstract Cell Division is a new, open access, peer-reviewed online journal that publishes cutting-edge articles, commentaries and reviews on all exciting aspects of cell cycle control in eukaryotes. A major goal of this new journal is to publish timely and significant studies on the aberrations of the cell cycle network that occur in cancer and other diseases.

  11. Radiotherapy and chemotherapy after partial synchronization of cell cycle

    International Nuclear Information System (INIS)

    Hermann, H.J.; Ammon, J.; Nuevemann, M.; Zum Winkel, K.; Technische Hochschule Aachen

    1977-01-01

    Apart from densely ionising radiations, radiotherapy and chemotherapy after partial synchronisation of the cell cycle are, at the moment, the only way to improve the efficiency of a treatment of malignant tumours. The new principle is based on the finding that tumour cells are more sensitive to radiation or chemotherapy in a certain metabolic situation. Partial synchronisation of the cell cycle makes it possible to enrich tumour cells in a certain metabolic state. In order to show the efficiency of such a measure, several methods can be used. Recently, impulse cytophotometry has been replacing these methods, since it permits a quick, simple, and individual control of the synchronisation effect. However, there has not been any clinical experiment yet to prove that tumour cells show a maximum sensitivity to radio- and chemotherapy in the G 2 -M-phase. This is why a number of patients with malignant tumours which could not be operated or treated with the usual radiotherapy or polychemotherapy were treated according to this new therapeutic principle. The results obtained in 233 cases encourage the specialists to continue the experiments. The indication of a treatment after partial synchronisation of the cell cycle should be based on the tumour spread as documented according to the TNM-system. Only when these guidelines are followed will it be possible to explain the problems still unsolved in the principle of radiotherapy and chemotherapy after partial synchronisation of the cell cycle and to carry out radio- and chemotherapy with improved efficiency in the future. (orig./MG) [de

  12. Cell cycle dependent RRM2 may serve as proliferation marker and pharmaceutical target in adrenocortical cancer.

    Science.gov (United States)

    Grolmusz, Vince Kornél; Karászi, Katalin; Micsik, Tamás; Tóth, Eszter Angéla; Mészáros, Katalin; Karvaly, Gellért; Barna, Gábor; Szabó, Péter Márton; Baghy, Kornélia; Matkó, János; Kovalszky, Ilona; Tóth, Miklós; Rácz, Károly; Igaz, Péter; Patócs, Attila

    2016-01-01

    Adrenocortical cancer (ACC) is a rare, but agressive malignancy with poor prognosis. Histopathological diagnosis is challenging and pharmacological options for treatment are limited. By the comparative reanalysis of the transcriptional malignancy signature with the cell cycle dependent transcriptional program of ACC, we aimed to identify novel biomarkers which may be used in the histopathological diagnosis and for the prediction of therapeutical response of ACC. Comparative reanalysis of publicly available microarray datasets included three earlier studies comparing transcriptional differences between ACC and benign adrenocortical adenoma (ACA) and one study presenting the cell cycle dependent gene expressional program of human ACC cell line NCI-H295R. Immunohistochemical analysis was performed on ACC samples. In vitro effects of antineoplastic drugs including gemcitabine, mitotane and 9-cis-retinoic acid alone and in combination were tested in the NCI-H295R adrenocortical cell line. Upon the comparative reanalysis, ribonucleotide reductase subunit 2 (RRM2), responsible for the ribonucleotide dezoxyribonucleotide conversion during the S phase of the cell cycle has been validated as cell cycle dependently expressed. Moreover, its expression was associated with the malignancy signature, as well. Immunohistochemical analysis of RRM2 revealed a strong correlation with Ki67 index in ACC. Among the antiproliferative effects of the investigated compounds, gemcitabine showed a strong inhibition of proliferation and an increase of apoptotic events. Additionally, RRM2 has been upregulated upon gemcitabine treatment. Upon our results, RRM2 might be used as a proliferation marker in ACC. RRM2 upregulation upon gemcitabine treatment might contribute to an emerging chemoresistance against gemcitabine, which is in line with its limited therapeutical efficacy in ACC, and which should be overcome for successful clinical applications.

  13. Circadian Clock Synchronization of the Cell Cycle in Zebrafish Occurs through a Gating Mechanism Rather Than a Period-phase Locking Process.

    Science.gov (United States)

    Laranjeiro, Ricardo; Tamai, T Katherine; Letton, William; Hamilton, Noémie; Whitmore, David

    2018-04-01

    Studies from a number of model systems have shown that the circadian clock controls expression of key cell cycle checkpoints, thus providing permissive or inhibitory windows in which specific cell cycle events can occur. However, a major question remains: Is the clock actually regulating the cell cycle through such a gating mechanism or, alternatively, is there a coupling process that controls the speed of cell cycle progression? Using our light-responsive zebrafish cell lines, we address this issue directly by synchronizing the cell cycle in culture simply by changing the entraining light-dark (LD) cycle in the incubator without the need for pharmacological intervention. Our results show that the cell cycle rapidly reentrains to a shifted LD cycle within 36 h, with changes in p21 expression and subsequent S phase timing occurring within the first few hours of resetting. Reentrainment of mitosis appears to lag S phase resetting by 1 circadian cycle. The range of entrainment of the zebrafish clock to differing LD cycles is large, from 16 to 32 hour periods. We exploited this feature to explore cell cycle entrainment at both the population and single cell levels. At the population level, cell cycle length is shortened or lengthened under corresponding T-cycles, suggesting that a 1:1 coupling mechanism is capable of either speeding up or slowing down the cell cycle. However, analysis at the single cell level reveals that this, in fact, is not true and that a gating mechanism is the fundamental method of timed cell cycle regulation in zebrafish. Cell cycle length at the single cell level is virtually unaltered with varying T-cycles.

  14. Solid Oxide Fuel Cell Systems PVL Line

    International Nuclear Information System (INIS)

    Shearer, Susan; Rush, Gregory

    2012-01-01

    In July 2010, Stark State College (SSC), received Grant DE-EE0003229 from the U.S. Department of Energy (DOE), Golden Field Office, for the development of the electrical and control systems, and mechanical commissioning of a unique 20kW scale high-pressure, high temperature, natural gas fueled Stack Block Test System (SBTS). SSC worked closely with subcontractor, Rolls-Royce Fuel Cell Systems (US) Inc. (RRFCS) over a 13 month period to successfully complete the project activities. This system will be utilized by RRFCS for pre-commercial technology development and training of SSC student interns. In the longer term, when RRFCS is producing commercial products, SSC will utilize the equipment for workforce training. In addition to DOE Hydrogen, Fuel Cells, and Infrastructure Technologies program funding, RRFCS internal funds, funds from the state of Ohio, and funding from the DOE Solid State Energy Conversion Alliance (SECA) program have been utilized to design, develop and commission this equipment. Construction of the SBTS (mechanical components) was performed under a Grant from the State of Ohio through Ohio's Third Frontier program (Grant TECH 08-053). This Ohio program supported development of a system that uses natural gas as a fuel. Funding was provided under the Department of Energy (DOE) Solid-state Energy Conversion Alliance (SECA) program for modifications required to test on coal synthesis gas. The subject DOE program provided funding for the electrical build, control system development and mechanical commissioning. Performance testing, which includes electrical commissioning, was subsequently performed under the DOE SECA program. Rolls-Royce Fuel Cell Systems is developing a megawatt-scale solid oxide fuel cell (SOFC) stationary power generation system. This system, based on RRFCS proprietary technology, is fueled with natural gas, and operates at elevated pressure. A critical success factor for development of the full scale system is the capability to

  15. Sequentially administrated of pemetrexed with icotinib/erlotinib in lung adenocarcinoma cell lines in vitro.

    Science.gov (United States)

    Feng, Xiuli; Zhang, Yan; Li, Tao; Li, Yu

    2017-12-26

    Combination of chemotherapy and epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) had been proved to be a potent anti-drug for the treatment of tumors. However, survival time was not extended for the patients with lung adenocarcinoma (AdC) compared with first-line chemotherapy. In the present study, we attempt to assess the optimal schedule of the combined administration of pemetrexed and icotinib/erlotinib in AdC cell lines. Human lung AdC cell lines with wild-type (A549), EGFR T790M (H1975) and activating EGFR mutation (HCC827) were applied in vitro to assess the differential efficacy of various sequential regimens on cell viability, cell apoptosis and cell cycle distribution. The results suggested that the antiproliferative effect of the sequence of pemetrexed followed by icotinib/erlotinib was more effective than that of icotinib/erlotinib followed by pemetrexed. Additionally, a reduction of G1 phase and increased S phase in sequence of pemetrexed followed by icotinib/erlotinib was also observed, promoting cell apoptosis. Thus, the sequential administration of pemetrexed followed by icotinib/erlotinib exerted a synergistic effect on HCC827 and H1975 cell lines compared with the reverse sequence. The sequential treatment of pemetrexed followed by icotinib/erlotinib has been demonstrated promising results. This treatment strategy warrants further confirmation in patients with advanced lung AdC.

  16. The Genomic and Transcriptomic Landscape of a HeLa Cell Line

    Science.gov (United States)

    Landry, Jonathan J. M.; Pyl, Paul Theodor; Rausch, Tobias; Zichner, Thomas; Tekkedil, Manu M.; Stütz, Adrian M.; Jauch, Anna; Aiyar, Raeka S.; Pau, Gregoire; Delhomme, Nicolas; Gagneur, Julien; Korbel, Jan O.; Huber, Wolfgang; Steinmetz, Lars M.

    2013-01-01

    HeLa is the most widely used model cell line for studying human cellular and molecular biology. To date, no genomic reference for this cell line has been released, and experiments have relied on the human reference genome. Effective design and interpretation of molecular genetic studies performed using HeLa cells require accurate genomic information. Here we present a detailed genomic and transcriptomic characterization of a HeLa cell line. We performed DNA and RNA sequencing of a HeLa Kyoto cell line and analyzed its mutational portfolio and gene expression profile. Segmentation of the genome according to copy number revealed a remarkably high level of aneuploidy and numerous large structural variants at unprecedented resolution. Some of the extensive genomic rearrangements are indicative of catastrophic chromosome shattering, known as chromothripsis. Our analysis of the HeLa gene expression profile revealed that several pathways, including cell cycle and DNA repair, exhibit significantly different expression patterns from those in normal human tissues. Our results provide the first detailed account of genomic variants in the HeLa genome, yielding insight into their impact on gene expression and cellular function as well as their origins. This study underscores the importance of accounting for the strikingly aberrant characteristics of HeLa cells when designing and interpreting experiments, and has implications for the use of HeLa as a model of human biology. PMID:23550136

  17. Cell cycle related /sup 125/IUDR-induced-division delay

    International Nuclear Information System (INIS)

    Scheniderman, M.H.; Hofer, K.G.

    1987-01-01

    A series of experiments were run to determine if /sup 125/I-decays, in /sup 125/IUdR labeled DNA, specifically accumulated at 1, 3, 5, 7 and 9 hours after plating labeled mitotic cells caused a change in the rate or time of cell entry into mitosis. To accomplish this, a pool of labeled mitotic cells was selected in mitosis and plated in replicate flasks. /sup 125/I decays were accumulated in groups of cells by cooling (4 0 C) for 2 hours starting at the designated times. After rewarding, colcemid was added to arrest cells in mitosis. The rate of cell progression into mitosis for each cell cycle time of accumulation was determined by scoring the mitotic index of cells sampled as a function of time after addition of the colcemid. The results are summarized: (1) Decays from /sup 125/I in /sup 125/I(UdR) labeled DNA reduced the rate of cell progression into mitosis and delayed the time of initiation of mitosis. (2) The reduced rate of progression and the delayed time of initiation of mitosis were independent of the cell cycle time that /sup 125/I-decays were accumulated. (3) The reduced rate of progression after cell cycle accumulation of /sup 125/I decay was statistically indistinguishable from the corresponding controls. (4) The delayed initiation of mitosis after specific cell cycle accumulation of /sup 125/I- decays was greater than the corresponding control. The relationship of these data to DNA and non-DNA division delay target(s) is emphasized

  18. Cell cycle in egg cell and its progression during zygotic development in rice.

    Science.gov (United States)

    Sukawa, Yumiko; Okamoto, Takashi

    2018-03-01

    Rice egg is arrested at G1 phase probably by OsKRP2. After fusion with sperm, karyogamy, OsWEE1-mediated parental DNA integrity in zygote nucleus, zygote progresses cell cycle to produce two-celled embryo. In angiosperms, female and male gametes exist in gametophytes after the complementation of meiosis and the progression of nuclear/cell division of the haploid cell. Within the embryo sac, the egg cell is specially differentiated for fertilization and subsequent embryogenesis, and cellular programs for embryonic development, such as restarting the cell cycle and de novo gene expression, are halted. There is only limited knowledge about how the cell cycle in egg cells restarts toward zygotic division, although the conversion of the cell cycle from a quiescent and arrested state to an active state is the most evident transition of cell status from egg cell to zygote. This is partly due to the difficulty in direct access and analysis of egg cells, zygotes and early embryos, which are deeply embedded in ovaries. In this study, precise relative DNA amounts in the nuclei of egg cells, developing zygotes and cells of early embryos were measured, and the cell cycle of a rice egg cell was estimated as the G1 phase with a 1C DNA level. In addition, increases in DNA content in zygote nuclei via karyogamy and DNA replication were also detectable according to progression of the cell cycle. In addition, expression profiles for cell cycle-related genes in egg cells and zygotes were also addressed, and it was suggested that OsKRP2 and OsWEE1 function in the inhibition of cell cycle progression in egg cells and in checkpoint of parental DNA integrity in zygote nucleus, respectively.

  19. Radiosensitivity of prostatic cell lines: bicalutamide effect (Casodex), micro-RNAs actions

    International Nuclear Information System (INIS)

    Quero, J.L.

    2011-10-01

    The first aim of our study was to evaluate the effect of the association between bicalutamide, an androgen receptor inhibitor, and ionizing radiation in three prostate cancer cell lines. The second aim was to examine a possible correlation between the expression of miR-210 or miR-373, the tolerance to hypoxia tolerance and the responses to radiation.We found that bicalutamide produced cytostatic and cytotoxic effects in the androgen receptor- positive LNCaP cell line. The androgen receptor-negative DU145 and PC3 cell lines were more resistant to bicalutamide. However, these cell lines were affected by high bicalutamide concentration with the same endpoints as for LNCaP cells. The inhibition of proliferation by bicalutamide was associated with G1 cell cycle phase arrest, increased expression of p27KIP1 protein, and decreased expression of HER2 protein. Last but not least, bicalutamide elicited a marked radioprotective effect in LNCaP cells when associated with concomitant irradiation. This result suggests that bicalutamide and radiotherapy should not be delivered in close temporal proximity, especially in case of hypo-fractionated radiotherapy protocols.Hypoxia is a well known radioresistance factor in tumors and is associated with a bad prognosis in prostate cancer. In this study, we found that hypoxia promotes the expression of HIF-1α, CA9, VEGF and miR-210 but not miR-373 in prostate cancer cell lines irrespective of their androgen receptor status.Our findings suggest that miR-210 expression is correlated with resistance to hypoxia and could be used as a prognostic marker in prostate cancer. Conversely, miR-210 inhibition did not impact the radiation susceptibility of PC3 prostate cancer cell line under hypoxia. (author)

  20. Canthin-6-one induces cell death, cell cycle arrest and differentiation in human myeloid leukemia cells.

    Science.gov (United States)

    Vieira Torquato, Heron F; Ribeiro-Filho, Antonio C; Buri, Marcus V; Araújo Júnior, Roberto T; Pimenta, Renata; de Oliveira, José Salvador R; Filho, Valdir C; Macho, Antonio; Paredes-Gamero, Edgar J; de Oliveira Martins, Domingos T

    2017-04-01

    Canthin-6-one is a natural product isolated from various plant genera and from fungi with potential antitumor activity. In the present study, we evaluate the antitumor effects of canthin-6-one in human myeloid leukemia lineages. Kasumi-1 lineage was used as a model for acute myeloid leukemia. Cells were treated with canthin-6-one and cell death, cell cycle and differentiation were evaluated in both total cells (Lin + ) and leukemia stem cell population (CD34 + CD38 - Lin -/low ). Among the human lineages tested, Kasumi-1 was the most sensitive to canthin-6-one. Canthin-6-one induced cell death with apoptotic (caspase activation, decrease of mitochondrial potential) and necrotic (lysosomal permeabilization, double labeling of annexin V/propidium iodide) characteristics. Moreover, canthin-6-one induced cell cycle arrest at G 0 /G 1 (7μM) and G 2 (45μM) evidenced by DNA content, BrdU incorporation and cyclin B1/histone 3 quantification. Canthin-6-one also promoted differentiation of Kasumi-1, evidenced by an increase in the expression of myeloid markers (CD11b and CD15) and the transcription factor PU.1. Furthermore, a reduction of the leukemic stem cell population and clonogenic capability of stem cells were observed. These results show that canthin-6-one can affect Kasumi-1 cells by promoting cell death, cell cycle arrest and cell differentiation depending on concentration used. Canthin-6-one presents an interesting cytotoxic activity against leukemic cells and represents a promising scaffold for the development of molecules for anti-leukemic applications, especially by its anti-leukemic stem cell activity. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Modelling cell cycle synchronisation in networks of coupled radial glial cells.

    Science.gov (United States)

    Barrack, Duncan S; Thul, Rüdiger; Owen, Markus R

    2015-07-21

    Radial glial cells play a crucial role in the embryonic mammalian brain. Their proliferation is thought to be controlled, in part, by ATP mediated calcium signals. It has been hypothesised that these signals act to locally synchronise cell cycles, so that clusters of cells proliferate together, shedding daughter cells in uniform sheets. In this paper we investigate this cell cycle synchronisation by taking an ordinary differential equation model that couples the dynamics of intracellular calcium and the cell cycle and extend it to populations of cells coupled via extracellular ATP signals. Through bifurcation analysis we show that although ATP mediated calcium release can lead to cell cycle synchronisation, a number of other asynchronous oscillatory solutions including torus solutions dominate the parameter space and cell cycle synchronisation is far from guaranteed. Despite this, numerical results indicate that the transient and not the asymptotic behaviour of the system is important in accounting for cell cycle synchronisation. In particular, quiescent cells can be entrained on to the cell cycle via ATP mediated calcium signals initiated by a driving cell and crucially will cycle in near synchrony with the driving cell for the duration of neurogenesis. This behaviour is highly sensitive to the timing of ATP release, with release at the G1/S phase transition of the cell cycle far more likely to lead to near synchrony than release during mid G1 phase. This result, which suggests that ATP release timing is critical to radial glia cell cycle synchronisation, may help us to understand normal and pathological brain development. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. N-(4-Hydroxyphenyl) retinamide potentiated paclitaxel for cell cycle arrest and apoptosis in glioblastoma C6 and RG2 cells

    Science.gov (United States)

    Janardhanan, Rajiv; Butler, Jonathan T.; Banik, Naren L.; Ray, Swapan K.

    2009-01-01

    Glioblastoma grows aggressively due to its ability to maintain abnormally high potentials for cell proliferation. The present study examines the synergistic actions of N-(4-hdroxyphenyl) retinamide (4-HPR) and paclitaxel (PTX) to control the growth of rat glioblastoma C6 and RG2 cell lines. 4-HPR induced astrocytic differentiation was accompanied by increased expression of the tight junction protein e-cadherin and sustained down regulation of Id2 (member of inhibitor of differentiation family), catalytic subunit of rat telomerase reverse transcriptase (rTERT), and proliferating cell nuclear antigen (PCNA). Flow cytometric analysis showed that the microtubule stabilizer PTX caused cell cycle deregulation due to G2/M arrest. This in turn could alter the fate of kinetochore-spindletube dynamics thereby halting cell cycle progression. An interesting observation was induction of G1/S arrest by combination of 4-HPR and PTX, altering the G2/M arrest induced by PTX alone. This was further ratified by the upregulation of tumor suppressor protein retinoblastoma, which repressed the expression of the key signaling moieties to induce G1/S arrest. Collectively, combination of 4-HPR and PTX diminished the survival factors (e.g., rTERT, PCNA, and Bcl-2) to make glioblastoma cells highly prone to apoptosis with activation of cysteine proteases (e.g., calpain, cathepsins, caspase-8, caspase-3) in two glioblastoma cell lines. Hence, combination 4-HPR and PTX can be considered as an effective therapeutic strategy for controlling the growth of heterogeneous glioblastoma cell populations. PMID:19285047

  3. [Screening serum response special antibodies of U251 cell line from surface display phage antibody library].

    Science.gov (United States)

    Yu, Min; Tan, De-Yong; Qian, Wei; Lai, Jian-Hua; Sun, Gui-Lin

    2004-05-01

    U251 cell is a sensitive cell line to serum, which stops at G0 phase of cell cycle in no-serum medium, and recovers growth when the serum is added into no-serum medium. The cell can express corresponding proteins in different phase of cell cycle. Therefore it is very signification for the study of cell cycle regulation mechanism that explores these proteins. In this paper, the mouse antibody phage display library was added into the bottle in which the serum starvation U251 cells had been cultured, and the special antibody phages were absorbed. Then the absorbed antibody phages were amplified by adding E. coli TG1 and helper phage M13K07. Amplified antibody phages were added into bottle in which the serum cultured cell after serum starvation (follow named as serum recovered cells) were incubated, so that the cell absorbed the no-special antibody phages for the serum starvation cell and the special antibody phages were in supernatant. The remaining no-special antibody phages in the supernatant were discarded by repeating above program 3-4 times. The pure special antibody phages were gotten, and amplified by adding the host cell E. coli TG1 and helper phage M13K07. Then the host bacterium infected special antibody phage was spread on the plate medium with ampicillin, and the monoclonal antibody phages were gotten. Using same as above program, the monoclonal antibody phages absorbed specially for serum recovered U251 cells were obtained when the serum recovered cells instead of serum starvation cells and serum starvation cells instead of serum recovered cells. In this study, ninety-six positive monoclonal antibody phages that absorbed specially the serum starvation cells and eighty-two positive monoclonal antibody phages that absorbed specially the serum recovered cells were obtained. By using cell immunochemistry assay, two special signification antibodies were obtained. one (No.11) was the strong response in serum starvation cells, the other (No.2) was the strong

  4. Angular-dependent light scattering from cancer cells in different phases of the cell cycle.

    Science.gov (United States)

    Lin, Xiaogang; Wan, Nan; Weng, Lingdong; Zhou, Yong

    2017-10-10

    Cancer cells in different phases of the cell cycle result in significant differences in light scattering properties. In order to harvest cancer cells in particular phases of the cell cycle, we cultured cancer cells through the process of synchronization. Flow cytometric analysis was applied to check the results of cell synchronization and prepare for light scattering measurements. Angular-dependent light scattering measurements of cancer cells arrested in the G1, S, and G2 phases have been performed. Based on integral calculations for scattering intensities from 5° to 10° and from 110° to 150°, conclusions have been reached. Clearly, the sizes of the cancer cells in different phases of the cell cycle dominated the forward scatter. Accompanying the increase of cell size with the progression of the cell cycle, the forward scattering intensity also increased. Meanwhile, the DNA content of cancer cells in every phase of the cell cycle is responsible for light scattering at large scatter angles. The higher the DNA content of cancer cells was, the greater the positive effect on the high-scattering intensity. As expected, understanding the relationships between the light scattering from cancer cells and cell cycles will aid in the development of cancer diagnoses. Also, it may assist in the guidance of antineoplastic drugs clinically.

  5. A hepatocellular carcinoma cell line producing mature hepatitis B viral particles

    International Nuclear Information System (INIS)

    Fellig, Yakov; Almogy, Gidon; Galun, Eithan; Ketzinel-Gilad, Mali

    2004-01-01

    Current in vitro models for hepatitis B virus (HBV) are based on human hepatoblastoma cell lines transfected with HBV genome. The objective of this work was to develop an in vitro, hepatocellular carcinoma (HCC)-based system supporting HBV full replication and producing mature viral particles. The FLC4 human HCC cell line was stably transfected with a plasmid carrying a head-to-tail dimer of the adwHBV genome. One of the clones, FLC4A10 II , exhibited prolonged expression of HBV, as was demonstrated by secreted levels of HBsAg, HBeAg, and HBV DNA in the culture medium of the growing cells. Furthermore, the cells produced HBV particles that were detected by a cesium chloride density gradient performed on the culture medium. Analysis by Southern blot revealed that HBV DNA has integrated into the FLC4A10 II cell genome. The presence of HBV in the FLC4A10 II cells did not cause alterations in cell morphology and the cells continued to resemble mature hepatocytes. They do exhibit a high mitotic activity. The new HBV stably transfected cell line, FLC4A10 II , can serve as an important tool for further exploration of HBV host-pathogen interaction, viral life cycle, and for assessing new antiviral agents

  6. Proteomic analysis of cell lines to identify the irinotecan resistance ...

    Indian Academy of Sciences (India)

    MADHU

    was selected from the wild-type LoVo cell line by chronic exposure to irinotecan ... dose–effect curves of anticancer drugs were drawn on semilogarithm .... alcohol metabolites daunorubicinol (Forrest and Gonzalez. 2000; Mordente et al. ..... Chen L, Huang C and Wei Y 2007 Proteomic analysis of liver cancer cells treated ...

  7. Novel human multiple myeloma cell line UHKT-893

    Czech Academy of Sciences Publication Activity Database

    Uherková, L.; Vančurová, I.; Vyhlídalová, I.; Pleschnerová, M.; Špička, I.; Mihalová, R.; Březinová, J.; Hodný, Zdeněk; Čermáková, K.; Polanská, V.; Marinov, I.; Jedelský, P.L.; Kuželová, K.; Stöckbauer, P.

    2013-01-01

    Roč. 37, č. 3 (2013), s. 320-326 ISSN 0145-2126 Institutional support: RVO:68378050 Keywords : human myeloma cell line * human multiple myeloma * plasma cell * IL-6 dependence * immunoglobulin * free light chain Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.692, year: 2013

  8. Frequency and distribution of Notch mutations in tumor cell lines

    International Nuclear Information System (INIS)

    Mutvei, Anders Peter; Fredlund, Erik; Lendahl, Urban

    2015-01-01

    Deregulated Notch signaling is linked to a variety of tumors and it is therefore important to learn more about the frequency and distribution of Notch mutations in a tumor context. In this report, we use data from the recently developed Cancer Cell Line Encyclopedia to assess the frequency and distribution of Notch mutations in a large panel of cancer cell lines in silico. Our results show that the mutation frequency of Notch receptor and ligand genes is at par with that for established oncogenes and higher than for a set of house-keeping genes. Mutations were found across all four Notch receptor genes, but with notable differences between protein domains, mutations were for example more prevalent in the regions encoding the LNR and PEST domains in the Notch intracellular domain. Furthermore, an in silico estimation of functional impact showed that deleterious mutations cluster to the ligand-binding and the intracellular domains of NOTCH1. For most cell line groups, the mutation frequency of Notch genes is higher than in associated primary tumors. Our results shed new light on the spectrum of Notch mutations after in vitro culturing of tumor cells. The higher mutation frequency in tumor cell lines indicates that Notch mutations are associated with a growth advantage in vitro, and thus may be considered to be driver mutations in a tumor cell line context. The online version of this article (doi:10.1186/s12885-015-1278-x) contains supplementary material, which is available to authorized users

  9. Thermodynamic analysis of a refrigeration cycle using regenerative heat exchanger - suction/liquid line

    Energy Technology Data Exchange (ETDEWEB)

    Tebchirani, Tarik Linhares; Matos, Rudmar Serafim [Pos graduate Programme in Mechanical Engineering (PGMEC), Universidade Federal do Parana, Curitiba, PR (Brazil)], e-mails: tarik@utfpr.edu.br, rudmar@demec.ufpr.br

    2010-07-01

    This paper presents results from thermodynamic comparison of a conventional compression cycle and a steam cycle that uses a heat exchanger countercurrent (liquid line/suction line) in an air conditioning system split. The main objective is to study the relationship between the COP and the mass variation of refrigerant to the effectiveness of the heat exchanger. The papers presented in the literature discuss the matter in a theoretical way, are summarized in tables of rare loss statements without specification of methods. The methodology of work is based on testing of an air conditioner operating conventionally and also with the heat exchanger for the determination of values and parameters of interest. The tests were performed in a thermal chamber with temperature controlled and equipped with a data acquisition system for reading and storage results. The refrigerant was R22. Besides making possible an assessment of the feasibility of cost-benefit thermodynamics, it is suggested a different method for installing the equipment type split. (author)

  10. A Dominant-Negative PPARγ Mutant Promotes Cell Cycle Progression and Cell Growth in Vascular Smooth Muscle Cells

    Directory of Open Access Journals (Sweden)

    Joey Z. Liu

    2009-01-01

    Full Text Available PPARγ ligands have been shown to have antiproliferative effects on many cell types. We herein report that a synthetic dominant-negative (DN PPARγ mutant functions like a growth factor to promote cell cycle progression and cell proliferation in human coronary artery smooth muscle cells (CASMCs. In quiescent CASMCs, adenovirus-expressed DN-PPARγ promoted G1→S cell cycle progression, enhanced BrdU incorporation, and increased cell proliferation. DN-PPARγ expression also markedly enhanced positive regulators of the cell cycle, increasing Rb and CDC2 phosphorylation and the expression of cyclin A, B1, D1, and MCM7. Conversely, overexpression of wild-type (WT or constitutively-active (CA PPARγ inhibited cell cycle progression and the activity and expression of positive regulators of the cell cycle. DN-PPARγ expression, however, did not up-regulate positive cell cycle regulators in PPARγ-deficient cells, strongly suggesting that DN-PPARγ effects on cell cycle result from blocking the function of endogenous wild-type PPARγ. DN-PPARγ expression enhanced phosphorylation of ERK MAPKs. Furthermore, the ERK specific-inhibitor PD98059 blocked DN-PPARγ-induced phosphorylation of Rb and expression of cyclin A and MCM7. Our data thus suggest that DN-PPARγ promotes cell cycle progression and cell growth in CASMCs by modulating fundamental cell cycle regulatory proteins and MAPK mitogenic signaling pathways in vascular smooth muscle cells (VSMCs.

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    Ly Quoc Trung

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

  13. Clonogenic cell line survival of a human liver cancer cell line SMMC-7721 after carbon ion irradiation with different LET

    International Nuclear Information System (INIS)

    Lei Suwen; Su Xu; Wang Jifang; Li Wenjian

    2003-01-01

    Objective: To investigate the survival fraction of a human liver cancer cell line SMMC-7721 following irradiation with carbon ions with different LET. Methods: cells of the human liver cancer cell line SMMC-7721 were irradiated with carbon ions (LET=30 and 70 keV/μm). The survival fraction was determined with clonogenic assay after 9 days incubation in a 5% CO 2 incubator at 37 degree C. Results: When the survival fractions of 70 keV/μm were D s = 0.1 and D s=0.01 absorption dose were 2.94 and 5.88 Gy respectively, and those of 30 keV/μm were 4.00 and 8.00 Gy respectively. Conclusion: For the SMMC-7721 cell line, 70 keV/μm is more effective for cell killing than 30 keV/μm

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

    Directory of Open Access Journals (Sweden)

    Hyun-Ho Kwak

    2016-01-01

    Full Text Available 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.

  15. Application of Nuclear Volume Measurements to Comprehend the Cell Cycle in Root-Knot Nematode-Induced Giant Cells

    Directory of Open Access Journals (Sweden)

    José Dijair Antonino de Souza Junior

    2017-06-01

    Full Text Available Root-knot nematodes induce galls that contain giant-feeding cells harboring multiple enlarged nuclei within the roots of host plants. It is recognized that the cell cycle plays an essential role in the set-up of a peculiar nuclear organization that seemingly steers nematode feeding site induction and development. Functional studies of a large set of cell cycle genes in transgenic lines of the model host Arabidopsis thaliana have contributed to better understand the role of the cell cycle components and their implication in the establishment of functional galls. Mitotic activity mainly occurs during the initial stages of gall development and is followed by an intense endoreduplication phase imperative to produce giant-feeding cells, essential to form vigorous galls. Transgenic lines overexpressing particular cell cycle genes can provoke severe nuclei phenotype changes mainly at later stages of feeding site development. This can result in chaotic nuclear phenotypes affecting their volume. These aberrant nuclear organizations are hampering gall development and nematode maturation. Herein we report on two nuclear volume assessment methods which provide information on the complex changes occurring in nuclei during giant cell development. Although we observed that the data obtained with AMIRA tend to be more detailed than Volumest (Image J, both approaches proved to be highly versatile, allowing to access 3D morphological changes in nuclei of complex tissues and organs. The protocol presented here is based on standard confocal optical sectioning and 3-D image analysis and can be applied to study any volume and shape of cellular organelles in various complex biological specimens. Our results suggest that an increase in giant cell nuclear volume is not solely linked to increasing ploidy levels, but might result from the accumulation of mitotic defects.

  16. A combined gas cooled nuclear reactor and fuel cell cycle

    Science.gov (United States)

    Palmer, David J.

    Rising oil costs, global warming, national security concerns, economic concerns and escalating energy demands are forcing the engineering communities to explore methods to address these concerns. It is the intention of this thesis to offer a proposal for a novel design of a combined cycle, an advanced nuclear helium reactor/solid oxide fuel cell (SOFC) plant that will help to mitigate some of the above concerns. Moreover, the adoption of this proposal may help to reinvigorate the Nuclear Power industry while providing a practical method to foster the development of a hydrogen economy. Specifically, this thesis concentrates on the importance of the U.S. Nuclear Navy adopting this novel design for its nuclear electric vessels of the future with discussion on efficiency and thermodynamic performance characteristics related to the combined cycle. Thus, the goals and objectives are to develop an innovative combined cycle that provides a solution to the stated concerns and show that it provides superior performance. In order to show performance, it is necessary to develop a rigorous thermodynamic model and computer program to analyze the SOFC in relation with the overall cycle. A large increase in efficiency over the conventional pressurized water reactor cycle is realized. Both sides of the cycle achieve higher efficiencies at partial loads which is extremely important as most naval vessels operate at partial loads as well as the fact that traditional gas turbines operating alone have poor performance at reduced speeds. Furthermore, each side of the cycle provides important benefits to the other side. The high temperature exhaust from the overall exothermic reaction of the fuel cell provides heat for the reheater allowing for an overall increase in power on the nuclear side of the cycle. Likewise, the high temperature helium exiting the nuclear reactor provides a controllable method to stabilize the fuel cell at an optimal temperature band even during transients helping

  17. Guidelines for the use of cell lines in biomedical research.

    Science.gov (United States)

    Geraghty, R J; Capes-Davis, A; Davis, J M; Downward, J; Freshney, R I; Knezevic, I; Lovell-Badge, R; Masters, J R W; Meredith, J; Stacey, G N; Thraves, P; Vias, M

    2014-09-09

    Cell-line misidentification and contamination with microorganisms, such as mycoplasma, together with instability, both genetic and phenotypic, are among the problems that continue to affect cell culture. Many of these problems are avoidable with the necessary foresight, and these Guidelines have been prepared to provide those new to the field and others engaged in teaching and instruction with the information necessary to increase their awareness of the problems and to enable them to deal with them effectively. The Guidelines cover areas such as development, acquisition, authentication, cryopreservation, transfer of cell lines between laboratories, microbial contamination, characterisation, instability and misidentification. Advice is also given on complying with current legal and ethical requirements when deriving cell lines from human and animal tissues, the selection and maintenance of equipment and how to deal with problems that may arise.

  18. CycleBase.org - a comprehensive multi-organism online database of cell-cycle experiments

    DEFF Research Database (Denmark)

    Gauthier, Nicholas Paul; Larsen, Malene Erup; Wernersson, Rasmus

    2007-01-01

    The past decade has seen the publication of a large number of cell-cycle microarray studies and many more are in the pipeline. However, data from these experiments are not easy to access, combine and evaluate. We have developed a centralized database with an easy-to-use interface, Cyclebase...

  19. Stochastic E2F activation and reconciliation of phenomenological cell-cycle models.

    Science.gov (United States)

    Lee, Tae J; Yao, Guang; Bennett, Dorothy C; Nevins, Joseph R; You, Lingchong

    2010-09-21

    The transition of the mammalian cell from quiescence to proliferation is a highly variable process. Over the last four decades, two lines of apparently contradictory, phenomenological models have been proposed to account for such temporal variability. These include various forms of the transition probability (TP) model and the growth control (GC) model, which lack mechanistic details. The GC model was further proposed as an alternative explanation for the concept of the restriction point, which we recently demonstrated as being controlled by a bistable Rb-E2F switch. Here, through a combination of modeling and experiments, we show that these different lines of models in essence reflect different aspects of stochastic dynamics in cell cycle entry. In particular, we show that the variable activation of E2F can be described by stochastic activation of the bistable Rb-E2F switch, which in turn may account for the temporal variability in cell cycle entry. Moreover, we show that temporal dynamics of E2F activation can be recast into the frameworks of both the TP model and the GC model via parameter mapping. This mapping suggests that the two lines of phenomenological models can be reconciled through the stochastic dynamics of the Rb-E2F switch. It also suggests a potential utility of the TP or GC models in defining concise, quantitative phenotypes of cell physiology. This may have implications in classifying cell types or states.

  20. Bifenthrin activates homotypic aggregation in human T-cell lines.

    Science.gov (United States)

    Hoffman, Nataly; Tran, Van; Daniyan, Anthony; Ojugbele, Olutosin; Pryor, Stephen C; Bonventre, Josephine A; Flynn, Katherine; Weeks, Benjamin S

    2006-03-01

    Here, we addressed the concern that, despite the lack of overt toxicity, exposure to low levels of the common household pyrethroid pesticide, bifenthrin, could cause harm to the immune system. To do this, we measure the effect of bifenthrin on phytohemagglutinin (PHA) activation of homotypic aggregation in human T-cell lines. The human CD4+ H9, and Jurkat cell lines and the human promonocyte U937 cell line, were exposed to varying concentrations of bifenthrin. Cell viability was determined using the AlmarBlue Toxicity Assay. Concentrations of bifenthrin which did not reduce cell viability were determined and these concentrations were tested for the effect of bifenthrin on PHA-mediated homotypic aggregation. Blocking antibodies to ICAM and LFA-1 were used to disrupt aggregation and a nonspecific IgG was used as a control. Bifenthrin was found to be nontoxic at concentrations ranging from 10(-4) to 10(-13) M. Bifenthrin did not inhibit PHA induced cell aggregation in all cell lines tested. However, at 10(-4) M, bifenthrin to form aggregates stimulated homotypic aggregation in the H9 and Jurkat T-cell lines. The bifenthrin-induced aggregate formation, like that seen with PHA, was blocked by treating the cells with antibodies to either LFA-1 or ICAM. The results here show that bifenthrin activates T-cell function by stimulating ICAM/LFA-1 mediated homotypic aggregation. This data suggests that exposure to bifenthrin, even at "acceptable" limits, can increase the risk for and frequency of inflammatory responses and diseases such as asthma.

  1. Establishment, immortalisation and characterisation of pteropid bat cell lines.

    Directory of Open Access Journals (Sweden)

    Gary Crameri

    Full Text Available BACKGROUND: Bats are the suspected natural reservoir hosts for a number of new and emerging zoonotic viruses including Nipah virus, Hendra virus, severe acute respiratory syndrome coronavirus and Ebola virus. Since the discovery of SARS-like coronaviruses in Chinese horseshoe bats, attempts to isolate a SL-CoV from bats have failed and attempts to isolate other bat-borne viruses in various mammalian cell lines have been similarly unsuccessful. New stable bat cell lines are needed to help with these investigations and as tools to assist in the study of bat immunology and virus-host interactions. METHODOLOGY/FINDINGS: Black flying foxes (Pteropus alecto were captured from the wild and transported live to the laboratory for primary cell culture preparation using a variety of different methods and culture media. Primary cells were successfully cultured from 20 different organs. Cell immortalisation can occur spontaneously, however we used a retroviral system to immortalise cells via the transfer and stable production of the Simian virus 40 Large T antigen and the human telomerase reverse transcriptase protein. Initial infection experiments with both cloned and uncloned cell lines using Hendra and Nipah viruses demonstrated varying degrees of infection efficiency between the different cell lines, although it was possible to infect cells in all tissue types. CONCLUSIONS/SIGNIFICANCE: The approaches developed and optimised in this study should be applicable to bats of other species. We are in the process of generating further cell lines from a number of different bat species using the methodology established in this study.

  2. An apoptotic cell cycle mutant in Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Villadsen, Ingrid

    1996-01-01

    The simple eukaryote Saccharomyces cerevisiae has proved to be a useful organism for elucidating the mechanisms that govern cell cycle progression in eukaryotic cells. The excellent in vivo system permits a cell cycle study using temperature sensitive mutants. In addition, it is possible to study...... many genes and gene products from higher eukaryotes in Saccharomyces cerevisiae because many genes and biological processes are homologous or similar in lower and in higher eukaryotes. The highly developed methods of genetics and molecular biology greatly facilitates studies of higher eukaryotic...... processes.Programmmed cell death with apoptosis plays a major role in development and homeostatis in most, if not all, animal cells. Apoptosis is a morphologically distinct form of death, that requires the activation of a highly regulated suicide program. Saccharomyces cerevisiae provides a new system...

  3. Expression of cyclin A in A549 cell line after treatment with arsenic trioxide

    Directory of Open Access Journals (Sweden)

    Agnieszka Żuryń

    2015-12-01

    Full Text Available Background: Arsenic trioxide (ATO is an effective drug used in acute promyelocytic leukemia (AML. Many reports suggest that ATO can also be applied as an anticancer agent for solid tumors in the future. The influence of arsenic trioxide on the expression of different cell cycle regulators is poorly recognized. The purpose of the current study is to investigate how arsenic trioxide affects cyclin A expression and localization in the A549 cell line.Materials and methods: Morphological and ultrastructural changes in A549 cells were observed using light and transmission electron microscopes. Cyclin A localization was determined by immunofluorescence. Image-based cytometry was applied to evaluate the effect of arsenic trioxide on apoptosis and the cell cycle. Expression of cyclin A mRNA was quantified by real-time PCR.Results: After treatment with arsenic trioxide, increased numbers of cells with cytoplasmic localization of cyclin A were observed. The doses of 10 and 15 μM ATO slightly reduced expression of cyclin A mRNA. The apoptotic phenotype of cells was poorly represented, and the Tali imagebased cytometry analysis showed low percentages of apoptotic cells. The A549 population displayed an enriched fraction of cells in G0/G1 phase in the presence of 5μM ATO, whereas starting from the higher concentrations of the drug, i.e. 10 and 15 μM ATO, the G2/M fraction was on the increase.Discussion: Low expression of cyclin A in the A549 cell line may constitute a potential factor determining arsenic trioxide resistance. It could be hypothesized that the observed alterations in cyclin A expression/distribution may correlate well with changes in cell cycle regulation in our model, which in turn determines the outcome of the treatment.

  4. Isolation of a primate embryonic stem cell line.

    OpenAIRE

    Thomson, J A; Kalishman, J; Golos, T G; Durning, M; Harris, C P; Becker, R A; Hearn, J P

    1995-01-01

    Embryonic stem cells have the ability to remain undifferentiated and proliferate indefinitely in vitro while maintaining the potential to differentiate into derivatives of all three embryonic germ layers. Here we report the derivation of a cloned cell line (R278.5) from a rhesus monkey blastocyst that remains undifferentiated in continuous passage for > 1 year, maintains a normal XY karyotype, and expresses the cell surface markers (alkaline phosphatase, stage-specific embryonic antigen 3, st...

  5. Sensory hair cell regeneration in the zebrafish lateral line.

    Science.gov (United States)

    Lush, Mark E; Piotrowski, Tatjana

    2014-10-01

    Damage or destruction of sensory hair cells in the inner ear leads to hearing or balance deficits that can be debilitating, especially in older adults. Unfortunately, the damage is permanent, as regeneration of the inner ear sensory epithelia does not occur in mammals. Zebrafish and other non-mammalian vertebrates have the remarkable ability to regenerate sensory hair cells and understanding the molecular and cellular basis for this regenerative ability will hopefully aid us in designing therapies to induce regeneration in mammals. Zebrafish not only possess hair cells in the ear but also in the sensory lateral line system. Hair cells in both organs are functionally analogous to hair cells in the inner ear of mammals. The lateral line is a mechanosensory system found in most aquatic vertebrates that detects water motion and aids in predator avoidance, prey capture, schooling, and mating. Although hair cell regeneration occurs in both the ear and lateral line, most research to date has focused on the lateral line due to its relatively simple structure and accessibility. Here we review the recent discoveries made during the characterization of hair cell regeneration in zebrafish. Copyright © 2014 Wiley Periodicals, Inc.

  6. Nestin expression in the cell lines derived from glioblastoma multiforme

    International Nuclear Information System (INIS)

    Veselska, Renata; Kuglik, Petr; Cejpek, Pavel; Svachova, Hana; Neradil, Jakub; Loja, Tomas; Relichova, Jirina

    2006-01-01

    Nestin is a protein belonging to class VI of intermediate filaments that is produced in stem/progenitor cells in the mammalian CNS during development and is consecutively replaced by other intermediate filament proteins (neurofilaments, GFAP). Down-regulated nestin may be re-expressed in the adult organism under certain pathological conditions (brain injury, ischemia, inflammation, neoplastic transformation). Our work focused on a detailed study of the nestin cytoskeleton in cell lines derived from glioblastoma multiforme, because re-expression of nestin together with down-regulation of GFAP has been previously reported in this type of brain tumor. Two cell lines were derived from the tumor tissue of patients treated for glioblastoma multiforme. Nestin and other cytoskeletal proteins were visualized using imunocytochemical methods: indirect immunofluorescence and immunogold-labelling. Using epifluorescence and confocal microscopy, we described the morphology of nestin-positive intermediate filaments in glioblastoma cells of both primary cultures and the derived cell lines, as well as the reorganization of nestin during mitosis. Our most important result came through transmission electron microscopy and provided clear evidence that nestin is present in the cell nucleus. Detailed information concerning the pattern of the nestin cytoskeleton in glioblastoma cell lines and especially the demonstration of nestin in the nucleus represent an important background for further studies of nestin re-expression in relationship to tumor malignancy and invasive potential

  7. SENSORY HAIR CELL REGENERATION IN THE ZEBRAFISH LATERAL LINE

    Science.gov (United States)

    Lush, Mark E.; Piotrowski, Tatjana

    2014-01-01

    Damage or destruction of sensory hair cells in the inner ear leads to hearing or balance deficits that can be debilitating, especially in older adults. Unfortunately, the damage is permanent, as regeneration of the inner ear sensory epithelia does not occur in mammals. Zebrafish and other non-mammalian vertebrates have the remarkable ability to regenerate sensory hair cells and understanding the molecular and cellular basis for this regenerative ability will hopefully aid us in designing therapies to induce regeneration in mammals. Zebrafish not only possess hair cells in the ear but also in the sensory lateral line system. Hair cells in both organs are functionally analogous to hair cells in the inner ear of mammals. The lateral line is a mechanosensory system found in most aquatic vertebrates that detects water motion and aids in predator avoidance, prey capture, schooling and mating. Although hair cell regeneration occurs in both the ear and lateral line, most research to date has focused on the lateral line due to its relatively simple structure and accessibility. Here we review the recent discoveries made during the characterization of hair cell regeneration in zebrafish. PMID:25045019

  8. In Vitro Effects of Bromoalkyl Phenytoin Derivatives on Regulated Death, Cell Cycle and Ultrastructure of Leukemia Cells.

    Science.gov (United States)

    Śladowska, Katarzyna; Opydo-Chanek, Małgorzata; Król, Teodora; Trybus, Wojciech; Trybus, Ewa; Kopacz-Bednarska, Anna; Handzlik, Jadwiga; Kieć-Kononowicz, Katarzyna; Mazur, Lidia

    2017-11-01

    To search for new antileukemic agents, the chemical structure of phenytoin was modified. A possible cytotoxic activity of three bromoalkyl phenytoin analogs, methyl 2-(1-(3-bromopropyl)-2,4-dioxo-5,5-diphenylimidazolidin-3-yl) propanoate (PH2), 1-(3-bromopropyl)-3-methyl-5,5-diphenylimidazolidine-2,4-dione (PH3) and 1-(4-bromobutyl)-3-methyl-5,5-diphenylimidazolidine-2,4-dione (PH4) on regulated cell death, the cell cycle and cell ultrastructure was assessed. The experiments were performed in vitro on HL-60 and U937 cells, using flow cytometry and electron microscopy methods. Application of PH2, PH3, and PH4 resulted in cell surface exposure of phosphatidylserine and plasma membrane impairment, caspase-8, -9, and -3/7 activation, dissipation of mitochondrial membrane potential, DNA breakage, cell-cycle disturbance and cell ultrastructural changes. In general, PH3 appeared to be the most active against the leukemia cells, and all bromoalkyl hydantoins, PH2-PH4, were more active in HL-60 cells than in U937 cells. The antileukemic activity of the bromoalkyl phenytoin analogs depended on the combination of N-hydantoin substituents and the human cell line used. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

  9. TGF-β Signaling Regulates Pancreatic β-Cell Proliferation through Control of Cell Cycle Regulator p27 Expression

    International Nuclear Information System (INIS)

    Suzuki, Tomoyuki; Dai, Ping; Hatakeyama, Tomoya; Harada, Yoshinori; Tanaka, Hideo; Yoshimura, Norio; Takamatsu, Tetsuro

    2013-01-01

    Proliferation of pancreatic β-cells is an important mechanism underlying β-cell mass adaptation to metabolic demands. Increasing β-cell mass by regeneration may ameliorate or correct both type 1 and type 2 diabetes, which both result from inadequate production of insulin by β-cells of the pancreatic islet. Transforming growth factor β (TGF-β) signaling is essential for fetal development and growth of pancreatic islets. In this study, we exposed HIT-T15, a clonal pancreatic β-cell line, to TGF-β signaling. We found that inhibition of TGF-β signaling promotes proliferation of the cells significantly, while TGF-β signaling stimulation inhibits proliferation of the cells remarkably. We confirmed that this proliferative regulation by TGF-β signaling is due to the changed expression of the cell cycle regulator p27. Furthermore, we demonstrated that there is no observed effect on transcriptional activity of p27 by TGF-β signaling. Our data show that TGF-β signaling mediates the cell-cycle progression of pancreatic β-cells by regulating the nuclear localization of CDK inhibitor, p27. Inhibition of TGF-β signaling reduces the nuclear accumulation of p27, and as a result this inhibition promotes proliferation of β-cells

  10. Evolution of cell cycle control: same molecular machines, different regulation

    DEFF Research Database (Denmark)

    de Lichtenberg, Ulrik; Jensen, Thomas Skøt; Brunak, Søren

    2007-01-01

    Decades of research has together with the availability of whole genomes made it clear that many of the core components involved in the cell cycle are conserved across eukaryotes, both functionally and structurally. These proteins are organized in complexes and modules that are activated or deacti......Decades of research has together with the availability of whole genomes made it clear that many of the core components involved in the cell cycle are conserved across eukaryotes, both functionally and structurally. These proteins are organized in complexes and modules that are activated...... for assembling the same molecular machines just in time for action....

  11. Rewiring carbohydrate catabolism differentially affects survival of pancreatic cancer cell lines with diverse metabolic profiles

    Science.gov (United States)

    Tataranni, Tiziana; Agriesti, Francesca; Ruggieri, Vitalba; Mazzoccoli, Carmela; Simeon, Vittorio; Laurenzana, Ilaria; Scrima, Rosella; Pazienza, Valerio; Capitanio, Nazzareno; Piccoli, Claudia

    2017-01-01

    An increasing body of evidence suggests that targeting cellular metabolism represents a promising effective approach to treat pancreatic cancer, overcome chemoresistance and ameliorate patient's prognosis and survival. In this study, following whole-genome expression analysis, we selected two pancreatic cancer cell lines, PANC-1 and BXPC-3, hallmarked by distinct metabolic profiles with specific concern to carbohydrate metabolism. Functional comparative analysis showed that BXPC-3 displayed a marked deficit of the mitochondrial respiratory and oxidative phosphorylation activity and a higher production of reactive oxygen species and a reduced NAD+/NADH ratio, indicating their bioenergetic reliance on glycolysis and a different redox homeostasis as compared to PANC-1. Both cell lines were challenged to rewire their metabolism by substituting glucose with galactose as carbon source, a condition inhibiting the glycolytic flux and fostering full oxidation of the sugar carbons. The obtained data strikingly show that the mitochondrial respiration-impaired-BXPC-3 cell line was unable to sustain the metabolic adaptation required by glucose deprivation/substitution, thereby resulting in a G2\\M cell cycle shift, unbalance of the redox homeostasis, apoptosis induction. Conversely, the mitochondrial respiration-competent-PANC-1 cell line did not show clear evidence of cell sufferance. Our findings provide a strong rationale to candidate metabolism as a promising target for cancer therapy. Defining the metabolic features at time of pancreatic cancer diagnosis and likely of other tumors, appears to be crucial to predict the responsiveness to therapeutic approaches or coadjuvant interventions affecting metabolism. PMID:28476035

  12. Understanding cell cycle and cell death regulation provides novel weapons against human diseases.

    Science.gov (United States)

    Wiman, K G; Zhivotovsky, B

    2017-05-01

    Cell division, cell differentiation and cell death are the three principal physiological processes that regulate tissue homoeostasis in multicellular organisms. The growth and survival of cells as well as the integrity of the genome are regulated by a complex network of pathways, in which cell cycle checkpoints, DNA repair and programmed cell death have critical roles. Disruption of genomic integrity and impaired regulation of cell death may both lead to uncontrolled cell growth. Compromised cell death can also favour genomic instability. It is becoming increasingly clear that dysregulation of cell cycle and cell death processes plays an important role in the development of major disorders such as cancer, cardiovascular disease, infection, inflammation and neurodegenerative diseases. Research achievements in these fields have led to the development of novel approaches for treatment of various conditions associated with abnormalities in the regulation of cell cycle progression or cell death. A better understanding of how cellular life-and-death processes are regulated is essential for this development. To highlight these important advances, the Third Nobel Conference entitled 'The Cell Cycle and Cell Death in Disease' was organized at Karolinska Institutet in 2016. In this review we will summarize current understanding of cell cycle progression and cell death and discuss some of the recent advances in therapeutic applications in pathological conditions such as cancer, neurological disorders and inflammation. © 2017 The Association for the Publication of the Journal of Internal Medicine.

  13. Glycoproteins and sialyl transferase of human B lymphoblastoid cell lines

    International Nuclear Information System (INIS)

    Lui, S.W.L.; Ng, M.H.

    1980-01-01

    We used two radiolabeling methods to study glycoproteins on the surface of lymphoblastoid cells. One of the methods affects tritiation of residues which are oxidized with galactose oxidase and the other causes tritiation of neuraminic acid residues. This approach was shown to allow a better resolution of cell surface glycoproteins than if either method were used alone. Glycoproteins of B 1 - 19 cells which harbor the Epstein-Barr virus genomes were compared with those of its parental cell line, BJAB, which does not harbor the viral genomes. These studies did not reveal a unique viral protein. A 28,000 mol. wt. glycoprotein was found to be the most prominent neuraminic acidlabeled product of B 1 - 19 cells and also of the two other cell lines, Raji and Ly38, which harbor the EBV genomes. A similar molecular weight species from BJAB cells identified by galactose oxidase labeling might be deficient in neuraminic acid residues as it was poorly labeled by the periodate oxidation method. The neuraminic acid content and level of sialyl transferase of BJAB cells were found to be lower than those of the other cell lines studied. (auth.)

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

    Directory of Open Access Journals (Sweden)

    Morris Robert

    2010-03-01

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

  15. Postirradiation expression of lethal mutations in an immortalized human keratinocyte cell line

    International Nuclear Information System (INIS)

    O'Reilly, S.; Mothersill, C.; Seymour, C.B.

    1994-01-01

    The quantification of the extent of delayed cell death and the rate and pattern of its occurrence in relation to the cell division cycle is important in radiotherapy and also in radiation transformation studies related to protection and dose limits. Here the numbers of lethal mutations occurring over 45 population doublings (clonal expansion to about 10 13 cells per cell originally surviving irradiation) was measured in an HPV 16 immortalized human keratinocyte cell lines used for transformation studies. The results showed that when postirradiation (dose range 1-6 Gy) growth curves were constructed, the difference in slopes could be accounted for entirely by correcting for the non-clonogenic fraction in the cell count, excluding a longer cell generation time as an explanation. When the cell loss was examined over the entire growth period of 6 weeks (about 45 doublings of the cell population), it was found to be dose dependent for the first two passages, but then to become more independent of dose. The results allow a time/cell generation dependent factor to be derived for the cell line and used in survival curve equations where effects of radiation are being measured at times distant from the original exposure. (author)

  16. Radiation-induced genetic instability: no association with changes in radiosensitivity or cell cycle checkpoints in C3H 10T1/2 mouse fibroblasts

    International Nuclear Information System (INIS)

    Crompton, N.E.A.; Emery, G.C.; Shi Yuquan; Sigg, M.; Blattmann, H.

    1998-01-01

    We investigated various phenotypic characteristics of radiation-induced morphologically transformed C3H 10T1/2 mouse fibroblasts. The cells were treated with 8 Gy x-rays, and type II/III foci were isolated. Cell lines were developed from these foci, and subsequently clones were established from these focal lines. The clones were examined for DNA content, radiosensitivity and inducible cell cycle arrests. Besides the morphological changes associated with the transformed state, the major difference between the isolated focal lines or derived clones and the parental C3H 10T1/2 line was one of ploidy. The transformed cells often displayed aneuploid and multiple polyploid populations. No change in the radiosensitivity of the transformed cells was observed. Furthermore, the two major radiation- and staurosporine-induced G1 and G2 cell cycle arrests observed in the parental cell line were also observed in the morphological transformants, suggesting that checkpoint function was normal. (orig.)

  17. MS4a4B, a CD20 homologue in T cells, inhibits T cell propagation by modulation of cell cycle.

    Directory of Open Access Journals (Sweden)

    Hui Xu

    2010-11-01

    Full Text Available MS4a4B, a CD20 homologue in T cells, is a novel member of the MS4A gene family in mice. The MS4A family includes CD20, FcεRIβ, HTm4 and at least 26 novel members that are characterized by their structural features: with four membrane-spanning domains, two extracellular domains and two cytoplasmic regions. CD20, FcεRIβ and HTm4 have been found to function in B cells, mast cells and hematopoietic cells respectively. However, little is known about the function of MS4a4B in T cell regulation. We demonstrate here that MS4a4B negatively regulates mouse T cell proliferation. MS4a4B is highly expressed in primary T cells, natural killer cells (NK and some T cell lines. But its expression in all malignant T cells, including thymoma and T hybridoma tested, was silenced. Interestingly, its expression was regulated during T cell activation. Viral vector-driven overexpression of MS4a4B in primary T cells and EL4 thymoma cells reduced cell proliferation. In contrast, knockdown of MS4a4B accelerated T cell proliferation. Cell cycle analysis showed that MS4a4B regulated T cell proliferation by inhibiting entry of the cells into S-G2/M phase. MS4a4B-mediated inhibition of cell cycle was correlated with upregulation of Cdk inhibitory proteins and decreased levels of Cdk2 activity, subsequently leading to inhibition of cell cycle progression. Our data indicate that MS4a4B negatively regulates T cell proliferation. MS4a4B, therefore, may serve as a modulator in the negative-feedback regulatory loop of activated T cells.

  18. MS4a4B, a CD20 homologue in T cells, inhibits T cell propagation by modulation of cell cycle.

    Science.gov (United States)

    Xu, Hui; Yan, Yaping; Williams, Mark S; Carey, Gregory B; Yang, Jingxian; Li, Hongmei; Zhang, Guang-Xian; Rostami, Abdolmohamad

    2010-11-01

    MS4a4B, a CD20 homologue in T cells, is a novel member of the MS4A gene family in mice. The MS4A family includes CD20, FcεRIβ, HTm4 and at least 26 novel members that are characterized by their structural features: with four membrane-spanning domains, two extracellular domains and two cytoplasmic regions. CD20, FcεRIβ and HTm4 have been found to function in B cells, mast cells and hematopoietic cells respectively. However, little is known about the function of MS4a4B in T cell regulation. We demonstrate here that MS4a4B negatively regulates mouse T cell proliferation. MS4a4B is highly expressed in primary T cells, natural killer cells (NK) and some T cell lines. But its expression in all malignant T cells, including thymoma and T hybridoma tested, was silenced. Interestingly, its expression was regulated during T cell activation. Viral vector-driven overexpression of MS4a4B in primary T cells and EL4 thymoma cells reduced cell proliferation. In contrast, knockdown of MS4a4B accelerated T cell proliferation. Cell cycle analysis showed that MS4a4B regulated T cell proliferation by inhibiting entry of the cells into S-G2/M phase. MS4a4B-mediated inhibition of cell cycle was correlated with upregulation of Cdk inhibitory proteins and decreased levels of Cdk2 activity, subsequently leading to inhibition of cell cycle progression. Our data indicate that MS4a4B negatively regulates T cell proliferation. MS4a4B, therefore, may serve as a modulator in the negative-feedback regulatory loop of activated T cells.

  19. Cell Cycle Regulation by Alternative Polyadenylation of CCND1.

    Science.gov (United States)

    Wang, Qiong; He, Guopei; Hou, Mengmeng; Chen, Liutao; Chen, Shangwu; Xu, Anlong; Fu, Yonggui

    2018-05-01

    Global shortening of 3'UTRs by alternative polyadenylation (APA) has been observed in cancer cells. However, the role of APA in cancer remains unknown. CCND1 is a proto-oncogene that regulates progression through the G1-S phase of the cell cycle; moreover, it has been observed to be switching to proximal APA sites in cancer cells. To investigate the biological function of the APA of CCND1, we edited the weak poly(A) signal (PAS) of the proximal APA site to a canonical PAS using the CRISPR/Cas9 method, which can force the cells to use a proximal APA site. Cell cycle profiling and proliferation assays revealed that the proximal APA sites of CCND1 accelerated the cell cycle and promoted cell proliferation, but UTR-APA and CR-APA act via different molecular mechanisms. These results indicate that PAS editing with CRISPR/Cas9 provides a good method by which to study the biological function of APA.

  20. Casein gene expression in mouse mammary epithelial cell lines: Dependence upon extracellular matrix and cell type

    International Nuclear Information System (INIS)

    Medina, D.; Oborn, C.J.; Li, M.L.; Bissell, M.J.

    1987-01-01

    The COMMA-D mammary cell line exhibits mammary-specific functional differentiation under appropriate conditions in cell culture. The cytologically heterogeneous COMMA-D parental line and the clonal lines DB-1, TA-5, and FA-1 derived from the COMMA-D parent were examined for similar properties of functional differentiation. In monolayer cell culture, the cell lines DB-1, TA-5, FA-1, and MA-4 were examined for expression of mammary-specific and epithelial-specific proteins by an indirect immunofluorescence assay. The clonal cell lines were relatively homogeneous in their respective staining properties and seemed to represent three subpopulations found in the heterogeneous parental COMMA-D lines. None of the four clonal lines appeared to represent myoepithelial cells. The cell lines were examined for expression of β-casein mRNA in the presence or absence of prolactin. The inducibility of β-casein in the COMMA-D cell line was further enhanced by a reconstituted basement membrane preparation enriched in laminin, collagen IV, and proteoglycans. These results support the hypothesis that the functional response of inducible mammary cell populations is a result of interaction among hormones, multiple extracellular matrix components, and specific cell types

  1. Variation in sensitizing effect of caffeine in human tumour cell lines after γ-irradiation

    International Nuclear Information System (INIS)

    Valenzuela, M.T.; Almodovar, M.R. de; Mateos, S.; McMillan, T.J.

    2000-01-01

    We have investigated whether the protective role of the G2 checkpoint has increasing importance when the p53-dependent G1 checkpoint is inactivated. We have studied the differential effect of caffeine by clonogenic assays and flow cytometry in three human tumour cell lines with different functionality of p53 protein. The radiosensitizing effect of caffeine (2 mM) expressed itself as a significant decrease in surviving fraction at 2 Gy and a significant increase in α-values in RT112 and TE671, both with non-functional p53. However, no radiosensitizing effect was seen in cells with a normal p53 function (MCF-7 BUS). Two millimoles of caffeine also caused important changes in the cell cycle progression after irradiation. MCF-7 BUS showed a G1 arrest after irradiation and an early G2 arrest but those cells that reached the second G2 did not arrest significantly. In contrast, TE671 exhibited radiosensitization by caffeine, no G1 arrest, a G2 arrest in those cells irradiated in G2, no significant accumulation in the second G2 but an overall delay in release from the first cell cycle, which could be abrogated by caffeine. RT112 was similar to TE671 except that the emphasis in a G2 arrest was shifted from the block in cells irradiated in G2 to those irradiated at other cell cycle phases. The data presented confirm that p53 status can be a significant determinant of the efficacy of caffeine as radiosensitizer in these tumour cell lines, and document the importance of the G2 checkpoint in this effect. (author)

  2. Identification of genes associated with cisplatin resistance in human oral squamous cell carcinoma cell line

    OpenAIRE

    Zhang Ping; Zhang Zhiyuan; Zhou Xiaojian; Qiu Weiliu; Chen Fangan; Chen Wantao

    2006-01-01

    Abstract Background Cisplatin is widely used for chemotherapy of head and neck squamous cell carcinoma. However, details of the molecular mechanism responsible for cisplatin resistance are still unclear. The aim of this study was to identify the expression of genes related to cisplatin resistance in oral squamous cell carcinoma cells. Methods A cisplatin-resistant cell line, Tca/cisplatin, was established from a cisplatin-sensitive cell line, Tca8113, which was derived from moderately-differe...

  3. Antiproliferative activity of flavonoids on several cancer cell lines.

    Science.gov (United States)

    Kawaii, S; Tomono, Y; Katase, E; Ogawa, K; Yano, M

    1999-05-01

    Twenty-seven Citrus flavonoids were examined for their antiproliferative activities against several tumor and normal human cell lines. As a result, 7 flavonoids were judged to be active against the tumor cell lines, while they had weak antiproliferative activity against the normal human cell lines. The rank order of potency was luteolin, natsudaidain, quercetin, tangeretin, eriodictyol, nobiletin, and 3,3',4',5,6,7,8-heptamethoxyflavone. The structure-activity relationship established from comparison among these flavones and flavanones showed that the ortho-catechol moiety in ring B and a C2-C3 double bond were important for the antiproliferative activity. As to polymethoxylated flavones, C-3 hydroxyl and C-8 methoxyl groups were essential for high activity.

  4. DNA double strand break repair in a radioresistant cell line

    International Nuclear Information System (INIS)

    Koval, T.M.; Kazmar, E.R.

    1987-01-01

    TN-368 lepidopteran insect cells are on the order of 100 times more resistant to the lethal effects of ionizing radiation than cultured mammalian cells. DNA double strand breaks (DSB) are believed by many to be the critical molecular lesion leading to cell death. The authors therefore measured the rejoining of DSB in TN-368 and V79 Chinese hamster cells. Cells were irradiated on ice with /sup 137/Cs γ rays at a dose rate of 2.5 Gy/min, incubated for various periods of time, and assayed for DNA DSB using the method of neutral elution. The kinetics of DSB rejoining following a dose of 90.2 Gy are similar for both cell lines. Approximately 80% of the DSB are rejoined in both lines by 1 hr postirradiation. However, no further rejoining occurs in the TN-368 cells through at least 6 hr postirradiation, whereas 90% of the DSB are rejoined in the V79 cells by 2 hr postirradiation. Other studies (from 22.6 to 226 Gy) demonstrate that the amount of rejoining of DSB varies inversely with dose for the V79 cells but remains constant for the TN-368 cells. These findings do not support the hypothesis that unrejoined DNA DSB represent the major lesion resulting in cell death

  5. Graphene Oxide Nanoribbons Induce Autophagic Vacuoles in Neuroblastoma Cell Lines

    Directory of Open Access Journals (Sweden)

    Emanuela Mari

    2016-11-01

    Full Text Available Since graphene nanoparticles are attracting increasing interest in relation to medical applications, it is important to understand their potential effects on humans. In the present study, we prepared graphene oxide (GO nanoribbons by oxidative unzipping of single-wall carbon nanotubes (SWCNTs and analyzed their toxicity in two human neuroblastoma cell lines. Neuroblastoma is the most common solid neoplasia in children. The hallmark of these tumors is the high number of different clinical variables, ranging from highly metastatic, rapid progression and resistance to therapy to spontaneous regression or change into benign ganglioneuromas. Patients with neuroblastoma are grouped into different risk groups that are characterized by different prognosis and different clinical behavior. Relapse and mortality in high risk patients is very high in spite of new advances in chemotherapy. Cell lines, obtained from neuroblastomas have different genotypic and phenotypic features. The cell lines SK-N-BE(2 and SH-SY5Y have different genetic mutations and tumorigenicity. Cells were exposed to low doses of GO for different times in order to investigate whether GO was a good vehicle for biological molecules delivering individualized therapy. Cytotoxicity in both cell lines was studied by measuring cellular oxidative stress (ROS, mitochondria membrane potential, expression of lysosomial proteins and cell growth. GO uptake and cytoplasmic distribution of particles were studied by Transmission Electron Microscopy (TEM for up to 72 h. The results show that GO at low concentrations increased ROS production and induced autophagy in both neuroblastoma cell lines within a few hours of exposure, events that, however, are not followed by growth arrest or death. For this reason, we suggest that the GO nanoparticle can be used for therapeutic delivery to the brain tissue with minimal effects on healthy cells.

  6. Dihydroartemisinin inhibits the human erythroid cell differentiation by altering the cell cycle

    International Nuclear Information System (INIS)

    Finaurini, Sara; Basilico, Nicoletta; Corbett, Yolanda; D’Alessandro, Sarah; Parapini, Silvia; Olliaro, Piero; Haynes, Richard K.; Taramelli, Donatella

    2012-01-01

    Artemisinin derivatives such as dihydroartemisinin (DHA) induce significant depletion of early embryonic erythroblasts in animal models. We have reported previously that DHA specifically targets pro-erythroblasts and basophilic erythroblasts, when human CD34+ stem cells are differentiated toward the erythroid lineage, indicating that a window of susceptibility to artemisinins may exist also in human developmental erythropoiesis during pregnancy. To better investigate the toxicity of artemisinin derivatives, the structure–activity relationship was evaluated against the K562 leukaemia cell line, used as a model for differentiating early human erythroblasts. All artemisinins derivatives, except deoxyartemisinin, inhibited both spontaneous and induced erythroid differentiation, confirming that the peroxide bridge is responsible for the erythro-toxicity. On the contrary, cell growth was markedly reduced by DHA, artemisone and artesunate but not by artemisinin, 10-deoxoartemisinin or deoxy-artemisinin. The substituent at position C-10 is responsible only for the anti-proliferative effect, since 10-deoxoartemisinin did not reduce cell growth but arrested the differentiation of K562 cells. In particular, the results showed that DHA resulted the most potent and rapidly acting compound of the drug family, causing (i) the decreased expression of GpA surface receptors and the down regulation the γ-globin gene; (ii) the alteration of S phase of cell cycle and (iii) the induction of programmed cell death of early erythroblasts in a dose dependent manner within 24 h. In conclusion, these findings confirm that the active metabolite DHA is responsible for the erythro-toxicity of most of artemisinins used in therapy. Thus, as long as no further clinical data are available, current WHO recommendations of avoiding malaria treatment with artemisinins during the first trimester of pregnancy remain valid.

  7. Cell cycle effects of L-sulforaphane, a major antioxidant from cruciferous vegetables: The role of the anaphase promoting complex.

    Science.gov (United States)

    Shelley, Zhaoping; Royce, Simon G; Ververis, Katherine; Karagiannis, Tom C

    2014-01-01

    L-sulforaphane (LSF) is a natural isothiocyanate found in cruciferous vegetables particularly broccoli. LSF has been identified as a potent antioxidant and anti-cancer agent and is widely known to regulate phase II detoxifying enzymes and induce cell cycle arrest or apoptosis in malignant cells in vitro and in vivo. Previous studies have found significant G2/M cell cycle arrest in response to LSF in various model of cancer and results have mainly been attributed to increased cyclin B1 protein levels and increased p21expression. Using genome-wide mRNA-Seq analysis we provide insights into the molecular mechanisms of action of LSF to identify a key pathway in cell cycle progression - the role of the anaphase promoting complex (APC) pathway. We evaluated gene expression changes in human erythroleukemic K562 cells following treatment with 15 μM LSF for 48h and compared them to immortalized human keratinocytes, human microvascular endothelial cells (HMEC-1) cells and normal human umbilical endothelial cells (HUVEC). We identified disparate gene expression changes in response to LSF between malignant and normal cells and immortalized cell lines. The results highlight significant down-regulation of kinase CDK1 which is suggestive that the existence and activity of APC/CDC20 complex will be inhibited along with its associated down-stream degradation of key cell cycle regulators preventing cell cycle progression from mitotic exit.

  8. Relation Between the Cell Volume and the Cell Cycle Dynamics in Mammalian cell

    International Nuclear Information System (INIS)

    Magno, A.C.G.; Oliveira, I.L.; Hauck, J.V.S.

    2016-01-01

    The main goal of this work is to add and analyze an equation that represents the volume in a dynamical model of the mammalian cell cycle proposed by Gérard and Goldbeter (2011) [1]. The cell division occurs when the cyclinB/Cdkl complex is totally degraded (Tyson and Novak, 2011)[2] and it reaches a minimum value. At this point, the cell is divided into two newborn daughter cells and each one will contain the half of the cytoplasmic content of the mother cell. The equations of our base model are only valid if the cell volume, where the reactions occur, is constant. Whether the cell volume is not constant, that is, the rate of change of its volume with respect to time is explicitly taken into account in the mathematical model, then the equations of the original model are no longer valid. Therefore, every equations were modified from the mass conservation principle for considering a volume that changes with time. Through this approach, the cell volume affects all model variables. Two different dynamic simulation methods were accomplished: deterministic and stochastic. In the stochastic simulation, the volume affects every model's parameters which have molar unit, whereas in the deterministic one, it is incorporated into the differential equations. In deterministic simulation, the biochemical species may be in concentration units, while in stochastic simulation such species must be converted to number of molecules which are directly proportional to the cell volume. In an effort to understand the influence of the new equation a stability analysis was performed. This elucidates how the growth factor impacts the stability of the model's limit cycles. In conclusion, a more precise model, in comparison to the base model, was created for the cell cycle as it now takes into consideration the cell volume variation (paper)

  9. Changes of Constituents and Activity to Apoptosis and Cell Cycle During Fermentation of Tea

    Science.gov (United States)

    Zhao, Hang; Zhang, Min; Zhao, Lu; Ge, Ya-kun; Sheng, Jun; Shi, Wei

    2011-01-01

    Tea is believed to be beneficial for health, and the effects of the fermentation process on its contributions to apoptosis and cell cycle arrest of gastric cancer cells have not been completely investigated. In this study, the chemical components in green tea, black tea and pu-erh tea aqueous extracts were analyzed and compared. The polysaccharide and caffeine levels were substantially higher in the fermented black tea and pu-erh tea, while the polyphenol level was higher in the unfermented green tea. Hence, a treatment of tea aqueous extract and the components, which are emerging as promising anticancer agents, were pursued to determine whether this treatment could lead to enhance apoptosis and cell cycle arrest. In the human gastric cancer cell line SGC-7901, the cell viability and flow cytometry analysis for apoptotic cells indicated effects in a dose-dependent inhibition manner for the three tea treatment groups. The apoptosis rates were found to be elevated after 48 h of treatment with 31.2, 125, and 500 μg/mL of green tea extract, the higher catechins content may be involved in the mechanism. Cell cycle was arrested in S phase in the fermented black tea and pu-erh tea, and the populations were significantly decreased in G2/M phases, possibly due to the oxidation of tea polyphenols, which causes an increase of theabrownins. CCC-HEL-1 normal cells were not sensitive to tea extract. These findings suggest that the fermentation process causes changes of the compounds which might be involved in the changes of cell proliferation inhibition, apoptosis induction and cell cycle arrest. PMID:21673927

  10. Dramatic repositioning of c-Myb to different promoters during the cell cycle observed by combining cell sorting with chromatin immunoprecipitation.

    Directory of Open Access Journals (Sweden)

    Anita M Quintana

    2011-02-01

    Full Text Available The c-Myb transcription factor is a critical regulator of proliferation and stem cell differentiation, and mutated alleles of c-Myb are oncogenic, but little is known about changes in c-Myb activity during the cell cycle. To map the association of c-Myb with specific target genes during the cell cycle, we developed a novel Fix-Sort-ChIP approach, in which asynchronously growing cells were fixed with formaldehyde, stained with Hoechst 33342 and separated into different cell cycle fractions by flow sorting, then processed for chromatin immunoprecipitation (ChIP assays. We found that c-Myb actively repositions, binding to some genes only in specific cell cycle phases. In addition, the specificity of c-Myb is dramatically different in small subpopulations of cells, for example cells in the G2/M phase of the cell cycle, than in the bulk population. The repositioning of c-Myb during the cell cycle is not due to changes in its expression and also occurs with ectopically expressed, epitope-tagged versions of c-Myb. The repositioning occurs in established cell lines, in primary human CD34+ hematopoietic progenitors and in primary human acute myeloid leukemia cells. The combination of fixation, sorting and ChIP analysis sheds new light on the dynamic nature of gene regulation during the cell cycle and provides a new type of tool for the analysis of gene regulation in small subsets of cells, such as cells in a specific phase of the cell cycle.

  11. Characterization of cloned cells from an immortalized fetal pulmonary type II cell line

    Energy Technology Data Exchange (ETDEWEB)

    Henderson, R.F.; Waide, J.J.; Lechner, J.F.

    1995-12-01

    A cultured cell line that maintained expression of pulmonary type II cell markers of differentiation would be advantageous to generate a large number of homogenous cells in which to study the biochemical functions of type II cells. Type II epithelial cells are the source of pulmonary surfactant and a cell of origin for pulmonary adenomas. Last year our laboratory reported the induction of expression of two phenotypic markers of pulmonary type II cells (alkaline phosphatase activity and surfactant lipid synthesis) in cultured fetal rat lung epithelial (FRLE) cells, a spontaneously immortalized cell line of fetal rat lung type II cell origin. Subsequently, the induction of the ability to synthesize surfactant lipid became difficult to repeat. We hypothesized that the cell line was heterogenuous and some cells were more like type II cells than others. The purpose of this study was to test this hypothesis and to obtain a cultured cell line with type II cell phenotypic markers by cloning several FRLE cells and characterizing them for phenotypic markers of type II cells (alkaline phosphatase activity and presence of surfactant lipids). Thirty cloned cell lines were analyzed for induced alkaline phosphatase activity (on x-axis) and for percent of phospholipids that were disaturated (i.e., surfactant).

  12. Antiproliferative effect of Tualang honey on oral squamous cell carcinoma and osteosarcoma cell lines

    Directory of Open Access Journals (Sweden)

    Ismail Noorliza M

    2010-09-01

    Full Text Available Abstract Background The treatment of oral squamous cell carcinomas (OSCC and human osteosarcoma (HOS includes surgery and/or radiotherapy which often lead to reduced quality of life. This study was aimed to study the antiproliferative activity of local honey (Tualang on OSCC and HOS cell lines. Methods Several concentrations of Tualang honey (1% - 20% were applied on OSCC and HOS cell lines for 3, 6, 12, 24, 48 and 72 hours. Morphological characteristics were observed under light and fluorescent microscope. Cell viability was assessed using MTT assay and the optical density for absorbance values in each experiment was measured at 570 nm by an ELISA reader. Detection of cellular apoptosis was done using the Annexin V-FITC Apoptosis Detection Kit. Results Morphological appearance showed apoptotic cellular changes like becoming rounded, reduction in cell number, blebbed membrane and apoptotic nuclear changes like nuclear shrinkage, chromatin condensation and fragmented nucleus on OSCC and HOS cell lines. Cell viability assay showed a time and dose-dependent inhibitory effect of honey on both cell lines. The 50% inhibitory concentration (IC50 for OSCC and HOS cell lines was found to be 4% and 3.5% respectively. The maximum inhibition of cell growth of ≥80% was obtained at 15% for both cell lines. Early apoptosis was evident by flow cytometry where percentage of early apoptotic cells increased in dose and time dependent manner. Conclusion Tualang honey showed antiproliferative effect on OSCC and HOS cell lines by inducing early apoptosis.

  13. The recruitability and cell-cycle state of intestinal stem cells

    International Nuclear Information System (INIS)

    Potten, C.S.; Chadwick, C.; Ijiri, K.; Tsubouchi, S.; Hanson, W.R.

    1984-01-01

    Evidence is presented which suggests that the crypts of the small intestine contain at least two discrete but interdependent classes of stem cells, some with discrete cell kinetic properties and some with discrete radiation responses or radiosensitivities. Very low doses of X rays or gamma rays, or neutrons, kill a few cells in the stem cell regions of the crypt in a sensitive dose-dependent manner. Similar doses generate several different cell kinetic responses within either the clonogenic fraction or the cells at the stem cell position within the crypt. The cell kinetic responses range from apparent recruitment of G0 clonogenic cells into cycle, to a marked shortening of the average cell cycle of the cells at the stem cell position. It is suggested that the cell kinetic changes may be the consequence of the cell destruction

  14. Life cycle assessment of hydrogen production and fuel cell systems

    International Nuclear Information System (INIS)

    Dincer, I.

    2007-01-01

    This paper details life cycle assessment (LCA) of hydrogen production and fuel cell system. LCA is a key tool in hydrogen and fuel cell technologies for design, analysis, development; manufacture, applications etc. Energy efficiencies and greenhouse gases and air pollution emissions have been evaluated in all process steps including crude oil and natural gas pipeline transportation, crude oil distillation, natural gas reprocessing, wind and solar electricity generation , hydrogen production through water electrolysis and gasoline and hydrogen distribution and utilization

  15. Cell cycle control by a minimal Cdk network.

    Directory of Open Access Journals (Sweden)

    Claude Gérard

    2015-02-01

    Full Text Available In present-day eukaryotes, the cell division cycle is controlled by a complex network of interacting proteins, including members of the cyclin and cyclin-dependent protein kinase (Cdk families, and the Anaphase Promoting Complex (APC. Successful progression through the cell cycle depends on precise, temporally ordered regulation of the functions of these proteins. In light of this complexity, it is surprising that in fission yeast, a minimal Cdk network consisting of a single cyclin-Cdk fusion protein can control DNA synthesis and mitosis in a manner that is indistinguishable from wild type. To improve our understanding of the cell cycle regulatory network, we built and analysed a mathematical model of the molecular interactions controlling the G1/S and G2/M transitions in these minimal cells. The model accounts for all observed properties of yeast strains operating with the fusion protein. Importantly, coupling the model's predictions with experimental analysis of alternative minimal cells, we uncover an explanation for the unexpected fact that elimination of inhibitory phosphorylation of Cdk is benign in these strains while it strongly affects normal cells. Furthermore, in the strain without inhibitory phosphorylation of the fusion protein, the distribution of cell size at division is unusually broad, an observation that is accounted for by stochastic simulations of the model. Our approach provides novel insights into the organization and quantitative regulation of wild type cell cycle progression. In particular, it leads us to propose a new mechanistic model for the phenomenon of mitotic catastrophe, relying on a combination of unregulated, multi-cyclin-dependent Cdk activities.

  16. The Design Space of the Embryonic Cell Cycle Oscillator.

    Science.gov (United States)

    Mattingly, Henry H; Sheintuch, Moshe; Shvartsman, Stanislav Y

    2017-08-08

    One of the main tasks in the analysis of models of biomolecular networks is to characterize the domain of the parameter space that corresponds to a specific behavior. Given the large number of parameters in most models, this is no trivial task. We use a model of the embryonic cell cycle to illustrate the approaches that can be used to characterize the domain of parameter space corresponding to limit cycle oscillations, a regime that coordinates periodic entry into and exit from mitosis. Our approach relies on geometric construction of bifurcation sets, numerical continuation, and random sampling of parameters. We delineate the multidimensional oscillatory domain and use it to quantify the robustness of periodic trajectories. Although some of our techniques explore the specific features of the chosen system, the general approach can be extended to other models of the cell cycle engine and other biomolecular networks. Copyright © 2017 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  17. Experimental infection of Leishmania (L. chagasi in a cell line derived from Lutzomyia longipalpis (Diptera:Psychodidae

    Directory of Open Access Journals (Sweden)

    Felio J Bello

    2005-10-01

    Full Text Available The present work describes the in vitro infection of a cell line Lulo, derived from Lutzomyia longipalpis embryonic tissue, by Leishmania chagasi promastigotes. This infection process is compared with a parallel one developed using the J774 cell line. The L. chagasi MH/CO/84/CI-044B strain was used for experimental infection in two cell lines. The cells were seeded on glass coverslips in 24-well plates to reach a final number of 2 x 10(5 cells/well. Parasites were added to the adhered Lulo and J774 cells in a 10:1 ratio and were incubated at 28 and 37ºC respectively. After 2, 4, 6, 8, and 10 days post-infection, the cells were extensively washed with PBS, fixed with methanol, and stained with Giemsa. The number of internalized parasites was determined by counting at least 400 cultured cells on each coverslip. The results showed continuous interaction between L. chagasi promastigotes with the cell lines. Some ultrastructural characteristics of the amastigote forms were observed using transmission electron microscopy. The highest percentage of infection in Lulo cells was registered on day 6 post-infection (29.6% and on day 4 in the J774 cells (51%. This work shows similarities and differences in the L. chagasi experimental infection process in the two cell lines. However, Lulo cells emerge as a new model to study the life-cycle of this parasite.

  18. Therapeutic implications of an enriched cancer stem-like cell population in a human osteosarcoma cell line

    International Nuclear Information System (INIS)

    Martins-Neves, Sara R; Lopes, Áurio O; Carmo, Anália do; Paiva, Artur A; Simões, Paulo C; Abrunhosa, Antero J; Gomes, Célia MF

    2012-01-01

    Osteosarcoma is a bone-forming tumor of mesenchymal origin that presents a clinical pattern that is consistent with the cancer stem cell model. Cells with stem-like properties (CSCs) have been identified in several tumors and hypothesized as the responsible for the relative resistance to therapy and tumor relapses. In this study, we aimed to identify and characterize CSCs populations in a human osteosarcoma cell line and to explore their role in the responsiveness to conventional therapies. CSCs were isolated from the human MNNG/HOS cell line using the sphere formation assay and characterized in terms of self-renewal, mesenchymal stem cell properties, expression of pluripotency markers and ABC transporters, metabolic activity and tumorigenicity. Cell's sensitivity to conventional chemotherapeutic agents and to irradiation was analyzed and related with cell cycle-induced alterations and apoptosis. The isolated CSCs were found to possess self-renewal and multipotential differentiation capabilities, express markers of pluripotent embryonic stem cells Oct4 and Nanog and the ABC transporters P-glycoprotein and BCRP, exhibit low metabolic activity and induce tumors in athymic mice. Compared with parental MNNG/HOS cells, CSCs were relatively more resistant to both chemotherapy and irradiation. None of the treatments have induced significant cell-cycle alterations and apoptosis in CSCs. MNNG/HOS osteosarcoma cells contain a stem-like cell population relatively resistant to conventional chemotherapeutic agents and irradiation. This resistant phenotype appears to be related with some stem features, namely the high expression of the drug efflux transporters P-glycoprotein and BCRP and their quiescent nature, which may provide a biological basis for resistance to therapy and recurrence commonly observed in osteosarcoma

  19. Therapeutic implications of an enriched cancer stem-like cell population in a human osteosarcoma cell line

    Directory of Open Access Journals (Sweden)

    Martins-Neves Sara R

    2012-04-01

    Full Text Available Abstract Background Osteosarcoma is a bone-forming tumor of mesenchymal origin that presents a clinical pattern that is consistent with the cancer stem cell model. Cells with stem-like properties (CSCs have been identified in several tumors and hypothesized as the responsible for the relative resistance to therapy and tumor relapses. In this study, we aimed to identify and characterize CSCs populations in a human osteosarcoma cell line and to explore their role in the responsiveness to conventional therapies. Methods CSCs were isolated from the human MNNG/HOS cell line using the sphere formation assay and characterized in terms of self-renewal, mesenchymal stem cell properties, expression of pluripotency markers and ABC transporters, metabolic activity and tumorigenicity. Cell's sensitivity to conventional chemotherapeutic agents and to irradiation was analyzed and related with cell cycle-induced alterations and apoptosis. Results The isolated CSCs were found to possess self-renewal and multipotential differentiation capabilities, express markers of pluripotent embryonic stem cells Oct4 and Nanog and the ABC transporters P-glycoprotein and BCRP, exhibit low metabolic activity and induce tumors in athymic mice. Compared with parental MNNG/HOS cells, CSCs were relatively more resistant to both chemotherapy and irradiation. None of the treatments have induced significant cell-cycle alterations and apoptosis in CSCs. Conclusions MNNG/HOS osteosarcoma cells contain a stem-like cell population relatively resistant to conventional chemotherapeutic agents and irradiation. This resistant phenotype appears to be related with some stem features, namely the high expression of the drug efflux transporters P-glycoprotein and BCRP and their quiescent nature, which may provide a biological basis for resistance to therapy and recurrence commonly observed in osteosarcoma.

  20. Comparison of micronucleus frequencies and proliferation kinetics in three X-irradiated cell lines

    International Nuclear Information System (INIS)

    Kaffenberger, W.; Becker, K.; Beuningen, D. van

    1990-01-01

    The kinetics of the occurrence of micronuclei was correlated with the survival of three mammalian cell lines of human, monkey, and mouse origin after irradiation with 240 kV X-rays. Particular attention was paid to the evaluation of the individual proliferation kinetics of the cell lines as well as to the characterization of micronuclei subpopulation with respect to size and possible biological importance using DNA and BUdR labelling techniques, fluorescence microscopy, and image analysis. The results demonstrate very characteristic size distributions of micronuclei for the three cell lines independent of radiation dose and time after irradiation. A close correlation between cell death and the occurrence of micronuclei (expressed as a calculated 'MN index') after irradiation could be established only when the kinetics of progression of cells through the cell cycle (e.g. the doubling time) and the biological characteristics of micronuclei (e.g. BUdR positivity, the micronucleus frequencies, and the number of micronuclei per main nucleus) were taken into account. Therefore, the micronucleus assay might not be useful as a quantitative perdictive assay in vivo but may allow qualitative estimations of radiation damage only because the necessary proliferation parameters of the cells might not be possible to establish in vivo. (orig.) [de

  1. Technoeconomy of different solid oxide fuel cell based hybrid cycle

    DEFF Research Database (Denmark)

    Rokni, Masoud

    2014-01-01

    Gas turbine, steam turbine and heat engine (Stirling engine) is used as bottoming cycle for a solid oxide fuel cell plant to compare different plants efficiencies, CO2 emissionsand plants cost in terms of $/kW. Each plant is then integrated with biomass gasification and finally six plants...

  2. Biflorin induces cytotoxicity by DNA interaction in genetically different human melanoma cell lines.

    Science.gov (United States)

    Ralph, Ana Carolina Lima; Calcagno, Danielle Queiroz; da Silva Souza, Luciana Gregório; de Lemos, Telma Leda Gomes; Montenegro, Raquel Carvalho; de Arruda Cardoso Smith, Marília; de Vasconcellos, Marne Carvalho

    2016-08-01

    Cancer is a public health problem and the second leading cause of death worldwide. The incidence of cutaneous melanoma has been notably increasing, resulting in high aggressiveness and poor survival rates. Taking into account the antitumor activity of biflorin, a substance isolated from Capraria biflora L. roots that is cytotoxic in vitro and in vivo, this study aimed to demonstrate the action of biflorin against three established human melanoma cell lines that recapitulate the molecular landscape of the disease in terms of genetic alterations and mutations, such as the TP53, NRAS and BRAF genes. The results presented here indicate that biflorin reduces the viability of melanoma cell lines by DNA interactions. Biflorin causes single and double DNA strand breaks, consequently inhibiting cell cycle progression, replication and DNA repair and promoting apoptosis. Our data suggest that biflorin could be considered as a future therapeutic option for managing melanoma. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Gene mutation in ATM/PI3K region of nasopharyngeal carcinoma cell lines

    International Nuclear Information System (INIS)

    Wang Hongmei; Wu Xinyao; Xia Yunfei

    2002-01-01

    Objective: To define the correlation between nasopharyngeal carcinoma (NPC) cell radiosensitivity and gene mutation in the ATM/PI3K coding region. Methods: The gene mutation in the ATM/PI3K region of nasopharyngeal carcinoma cell lines which vary in radiosensitivity, was monitored by reverse transcription-polymerase chain reaction (RT-PCR) and fluorescence-marked ddNTP cycle sequencing technique. Results: No gene mutation was detected in the ATM/PI3K region of either CNE1 or CNE2. Conclusion: Disparity in intrinsic radiosensitivity between different NPC cell lines depends on some other factors and mechanism without being related to ATM/PI3K mutations

  4. Cell cycle phase dependent emergence of thymidylate synthase studied by monoclonal antibody (M-TS-4).

    Science.gov (United States)

    Shibui, S; Hoshino, T; Iwasaki, K; Nomura, K; Jastreboff, M M

    1989-05-01

    A method of identifying thymidylate synthase (TS) at the cellular level was developed using anti-TS monoclonal antibody (M-TS-4), a monoclonal antibody created against purified TS from a HeLa cell line. In HeLa cells and four human glioma cell lines (U-251, U-87, 343-MGA, and SF-188), TS was identified primarily in the cytoplasm. Autoradiographic and flow cytometric studies showed that TS appeared mainly in the G1 phase and subsided early in the S phase; thus, the G1 phase can be divided into TS-positive and -negative fractions. Nuclear TS was not demonstrated unequivocally with M-TS-4, and the relationship between nuclear TS and DNA synthesis could not be determined. Although the percentage of TS-positive cells was larger than the S-phase fraction measured by autoradiography after a pulse of tritiated thymidine or by the immunoperoxidase method using BUdR, the ratios were within a similar range (1.2-1.4) in all cell lines studied. Therefore, the S-phase fraction can be estimated indirectly from the percentage of TS-positive cells measured by M-TS-4. Because the emergence of TS detected by our method is cell cycle dependent, M-TS-4 may be useful for biochemical studies of TS and for cytokinetic analysis.

  5. How to Achieve Supply Chain Sustainability Efficiently? Taming the Triple Bottom Line Split Business Cycle

    Directory of Open Access Journals (Sweden)

    Matthias Klumpp

    2018-02-01

    Full Text Available For sustainable supply chains, specific concepts regarding how to efficiently improve sustainability are needed in a global comprehensive triple bottom line (TBL approach, especially for forwarders as central actors in supply chain design. Such specific advice is provided by reporting empirical DEA Malmquist index findings from seven large European forwarders regarding a TBL sustainability analysis from 2006 to 2016. A major obstacle in improving sustainability consists in the newly discovered fact that with the business cycle, the three TBL areas of economic, ecologic and social objectives for logistics are undergoing different up- and down-ward trends, making it very hard to improve all three simultaneously. Additional factors are identified in the characteristics of size and government influence regarding the sustainability efficiency of forwarders. This has important impacts on supply chain design like e.g., with selection criteria.

  6. Maslinic acid inhibits proliferation of renal cell carcinoma cell lines and suppresses angiogenesis of endothelial cells

    Directory of Open Access Journals (Sweden)

    Parth Thakor

    2017-03-01

    Full Text Available Despite the introduction of many novel therapeutics in clinical practice, metastatic renal cell carcinoma (RCC remains a treatment-re-sistant cancer. As red and processed meat are considered risk factors for RCC, and a vegetable-rich diet is thought to reduce this risk, research into plant-based therapeutics may provide valuable complementary or alternative therapeutics for the management of RCC. Herein, we present the antiproliferative and antiangiogenic effects of maslinic acid, which occurs naturally in edible plants, particularly in olive fruits, and also in a variety of medicinal plants. Human RCC cell lines (ACHN, Caki-1, and SN12K1, endothelial cells (human umbilical vein endothelial cell line [HUVEC], and primary cultures of kidney proximal tubular epithelial cells (PTEC were treated with maslinic acid. Maslinic acid was relatively less toxic to PTEC when compared with RCC under similar experimental conditions. In RCC cell lines, maslinic acid induced a significant reduction in proliferation, proliferating cell nuclear antigen, and colony formation. In HUVEC, maslinic acid induced a significant reduction in capillary tube formation in vitro and vascular endothelial growth factor. This study provides a rationale for incorporating a maslinic acid–rich diet either to reduce the risk of developing kidney cancer or as an adjunct to existing antiangiogenic therapy to improve efficacy.

  7. The BNCT resistant fraction of cancer cells. An in vitro morphologic and cytofluorimetric study on a rat coloncarcinoma cell line

    International Nuclear Information System (INIS)

    Ferrari, C.; Clerici, A.M.; Mazzini, G.

    2006-01-01

    Given the high efficacy of the BNCT treatment, recurrences reasonably depends on the failure of a cell fraction to uptake and retain adequate levels of boronated compounds. Aim of this study is to identify, quantify and characterize the resistant cell fraction relative to the delivered boron concentration. Experiments were performed on the DHD/K12/TRb line by means of cytofluorimetric DNA analysis, plating efficiency and morphologic observations. Cells were incubated with p-boronophenylalanine (BPA) concentrations ranging from 10 to 40 ppm for 18 h. Following neutron exposure, cells were reseeded for subsequent morphologic observations, counting and DNA analysis. Samples of irradiated cells not BPA enriched and non-irradiated cells with and without boron were compared with them. After 24 hs there were no differences among the four conditions, in terms of number of recovered cells, morphology and cell cycle distribution. Starting from 48 hs and up to 7 days BPA irradiated cells showed growth in dimensions, important cell number reduction and multiclonal DNA profile worsening with time. After 9 days normally sized cell clones appeared confirming the presence of a resistant cell fraction able to restore the original cell population after 21 days. The incidence of surviving cells turned out to be in the range 0,026-0,05%. (author)

  8. Cellular and Phenotypic Characterization of Canine Osteosarcoma Cell Lines

    Directory of Open Access Journals (Sweden)

    Marie E. Legare, Jamie Bush, Amanda K. Ashley, Taka Kato, William H. Hanneman

    2011-01-01

    Full Text Available Canine and human osteosarcoma (OSA have many similarities, with the majority of reported cases occurring in the appendicular skeleton, gender predominance noted, high rate of metastasis at the time of presentation, and a lack of known etiology for this devastating disease. Due to poor understanding of the molecular mechanisms underlying OSA, we have characterized seven different OSA canine cell lines: Abrams, D17, Grey, Hughes, Ingles, Jarques, and Marisco and compared them to U2, a human OSA cell line, for the following parameters: morphology, growth, contact inhibition, migrational tendencies, alkaline phosphatase staining, heterologous tumor growth, double-strand DNA breaks, and oxidative damage. All results demonstrated the positive characteristics of the Abrams cell line for use in future studies of OSA. Of particular interest, the robust growth of a subcutaneous tumor and rapid pulmonary metastasis of the Abrams cell line in an immunocompromised mouse shows incredible potential for the future use of Abrams as a canine OSA model. Further investigations utilizing a canine cell model of OSA, such as Abrams, will be invaluable to understanding the molecular events underlying OSA, pharmaceutical inhibition of metastasis, and eventual prevention of this devastating disease.

  9. Mouse DRG Cell Line with Properties of Nociceptors.

    Science.gov (United States)

    Doran, Ciara; Chetrit, Jonathan; Holley, Matthew C; Grundy, David; Nassar, Mohammed A

    2015-01-01

    In vitro cell lines from DRG neurons aid drug discovery because they can be used for early stage, high-throughput screens for drugs targeting pain pathways, with minimal dependence on animals. We have established a conditionally immortal DRG cell line from the Immortomouse. Using immunocytochemistry, RT-PCR and calcium microfluorimetry, we demonstrate that the cell line MED17.11 expresses markers of cells committed to the sensory neuron lineage. Within a few hours under differentiating conditions, MED17.11 cells extend processes and following seven days of differentiation, express markers of more mature DRG neurons, such as NaV1.7 and Piezo2. However, at least at this time-point, the nociceptive marker NaV1.8 is not expressed, but the cells respond to compounds known to excite nociceptors, including the TRPV1 agonist capsaicin, the purinergic receptor agonist ATP and the voltage gated sodium channel agonist, veratridine. Robust calcium transients are observed in the presence of the inflammatory mediators bradykinin, histamine and norepinephrine. MED17.11 cells have the potential to replace or reduce the use of primary DRG culture in sensory, pain and developmental research by providing a simple model to study acute nociception, neurite outgrowth and the developmental specification of DRG neurons.

  10. Effect of selected insecticides on SF9 insect cell line

    International Nuclear Information System (INIS)

    Saleh, M.; Rahmo, A.; Hajjar, J.

    2013-01-01

    The toxic effect of three insecticides: dimethoate (organophosphate insecticide), acetamiprid (neonicotinoid insecticide) and deltamethrin (pyrethroid insecticide) were evaluated in vitro on cultured Sf9 cell line. Cell growth inhibition was measured by the 3- (4,5- dimethylthiazol - 2-yl) - 2,5 - diphenyl tetrazolium bromide (MTT) assay. Regression Analysis was used to estimate the 20% inhibition of cells growth (IC 20). The IC 20 values obtained for deltamethrin, acetamipridand dimethoate were: 46.8, 61.6 and 68.9 μM, respectively. The proportion of phagocytic cells was positively correlated with the applied concentrations of the insecticides. (author)

  11. Abnormal number cell division of human thyroid anaplastic carcinoma cell line, SW 1736

    Directory of Open Access Journals (Sweden)

    Keiichi Ikeda

    2015-12-01

    Full Text Available Cell division, during which a mother cell usually divides into two daughter cells during one cell cycle, is the most important physiological event of cell biology. We observed one-to-four cell division during imaging of live SW1736 human thyroid anaplastic carcinoma cells transfected with a plasmid expressing the hybrid protein of green fluorescent protein and histone 2B (plasmid eGFP-H2B. Analysis of the images revealed a mother cell divided into four daughter cells. And one of the abnormally divided daughter cells subsequently formed a dinucleate cell.

  12. Characterization of stem-like cells in a new astroblastoma cell line

    Energy Technology Data Exchange (ETDEWEB)

    Coban, Esra Aydemir; Kasikci, Ezgi [Department of Genetics and Bioengineering, Faculty of Engineering and Architecture, Yeditepe University, Istanbul (Turkey); Karatas, Omer Faruk [Molecular Biology and Genetics Department, Erzurum Technical University, Erzurum (Turkey); Suakar, Oznur; Kuskucu, Aysegul [Department of Medical Genetics, Yeditepe University Medical School and Yeditepe University Hospital, Istanbul (Turkey); Altunbek, Mine [Department of Genetics and Bioengineering, Faculty of Engineering and Architecture, Yeditepe University, Istanbul (Turkey); Türe, Uğur [Department of Neurosurgery, Yeditepe University School of Medicine, Istanbul (Turkey); Sahin, Fikrettin [Department of Genetics and Bioengineering, Faculty of Engineering and Architecture, Yeditepe University, Istanbul (Turkey); Bayrak, Omer Faruk, E-mail: ofbayrak@yeditepe.edu.tr [Department of Medical Genetics, Yeditepe University Medical School and Yeditepe University Hospital, Istanbul (Turkey)

    2017-03-15

    Cell lines established from tumors are the most commonly used models in cancer research, and their use in recent years has enabled a greater understanding of the biology of cancer and the means to develop effective treatment strategies. Astroblastomas are uncommon neuroepithelial tumors of glial origin, predominantly affecting young people, mainly teenagers and children, predominantly females. To date, only a single study has reported that astroblastomas contain a large number of neural stem-like cells, which had only a partial proliferation capacity and differentiation. Our objective was to establish an astroblastoma cell line to investigate the presence of astroblastic cells and cancer stem-like cells. The migratory and invasion abilities of the cells were quantified with invasion and migration assays and compared to a glioblastoma cell line. The presence of stem cells was detected with surface-marker analysis by using flow cytometry, and measuring the differentiation ability with a differentiation assay and the self-renewal capacity with a sphere-forming assay. These characteristics may determine whether this novel cell line is a model for astroblastomas that may have stem-cell characteristics. With this novel cell line, scientists can investigate the molecular pathways underlying astroblastomas and develop new therapeutic strategies for patients with these tumors. - Highlights: • An establishment of a novel astroblastoma cell line was proposed. • The presence of astroblastic cells and cancer stem-like cells was investigated. • The molecular pathways underlying astroblastomas may be investigated. • New therapeutic strategies for patients with astroblastoma may be developed.

  13. Cell-cycle synchronisation of bloodstream forms of Trypanosoma brucei using Vybrant DyeCycle Violet-based sorting.

    Science.gov (United States)

    Kabani, Sarah; Waterfall, Martin; Matthews, Keith R

    2010-01-01

    Studies on the cell-cycle of Trypanosoma brucei have revealed several unusual characteristics that differ from the model eukaryotic organisms. However, the inability to isolate homogenous populations of parasites in distinct cell-cycle stages has limited the analysis of trypanosome cell division and complicated the understanding of mutant phenotypes with possible impact on cell-cycle related events. Although hydroxyurea-induced cell-cycle arrest in procyclic and bloodstream forms has been applied recently with success, such block-release protocols can complicate the analysis of cell-cycle regulated events and have the potential to disrupt important cell-cycle checkpoints. An alternative approach based on flow cytometry of parasites stained with Vybrant DyeCycle Orange circumvents this problem, but is restricted to procyclic form parasites. Here, we apply Vybrant Dyecycle Violet staining coupled with flow cytometry to effectively select different cell-cycle stages of bloodstream form trypanosomes. Moreover, the sorted parasites remain viable, although synchrony is rapidly lost. This method enables cell-cycle enrichment of populations of trypanosomes in their mammal infective stage, particularly at the G1 phase.

  14. Hsa-let-7a functions as a tumor suppressor in renal cell carcinoma cell lines by targeting c-myc

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yongchao; Yin, Bingde; Zhang, Changcun; Zhou, Libin [Department of Urology, Shanghai First People' s Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200080 (China); Fan, Jie, E-mail: jief67@sina.com [Department of Urology, Shanghai First People' s Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200080 (China)

    2012-01-06

    Highlights: Black-Right-Pointing-Pointer This study is the first to test the let-7a/c-myc loop in renal cell carcinoma cell lines. Black-Right-Pointing-Pointer Let-7a down-regulated c-myc in three renal cell carcinoma cell lines. Black-Right-Pointing-Pointer c-myc target genes were down-regulated because of the let-7a-mediated down-regulation of c-myc. Black-Right-Pointing-Pointer The let-7a/c-myc loop has a significant function in renal cell carcinoma cell lines. -- Abstract: Widespread functions of the c-myc pathway play a crucial role in renal cell carcinoma (RCC) carcinogenesis. Thus, we evaluated the connection between proto-oncogenic c-myc and anti-neoplastic hsa-let-7a (let-7a) in RCC cell lines. The levels of c-myc and let-7a in 3 RCC cell lines (769P, Caki-1 and 786O) were measured after transfecting the cells with let-7a mimics or a negative control. The change in c-myc protein level was confirmed by Western blot. The anti-neoplastic function of let-7a was evaluated using cell counting kit-8 (CCK-8) for proliferation analysis and cell flow cytometry for cell cycle analysis. The changes of downstream targets of c-myc were measured using reverse transcription quantitative real-time PCR (qRT-PCR). Our results suggest for the first time that let-7a acts as a tumor suppressor in RCC cell lines by down-regulating c-myc and c-myc target genes such as proliferating cell nuclear antigen (PCNA), cyclin D1 (CCND1) and the miR17-92 cluster, which is accompanied by proliferation inhibition and cell cycle arrest.

  15. In vitro invasion of small-cell lung cancer cell lines correlates with expression of epidermal growth factor receptor

    DEFF Research Database (Denmark)

    Damstrup, L; Rude Voldborg, B; Spang-Thomsen, M

    1998-01-01

    receptor (EGFR) in a panel of 21 small-cell lung cancer (SCLC) cell lines. We have previously reported that ten of these cell lines expressed EGFR protein detected by radioreceptor and affinity labelling assays. In 11 small-cell lung cancer (SCLC) cell lines, EGFR mRNA was detected by Northern blot...... analysis. In vitro invasion in a Boyden chamber assay was found in all EGFR-positive cell lines, whereas no invasion was detected in the EGFR-negative cell lines. Quantification of the in vitro invasion in 12 selected SCLC cell lines demonstrated that, in the EGFR-positive cell lines, between 5% and 16......-PCR). However, in vitro invasive SCLC cell lines could not be distinguished from non-invasive cell lines based on the expression pattern of these molecules. In six SCLC cell lines, in vitro invasion was also determined in the presence of the EGFR-neutralizing monoclonal antibody mAb528. The addition...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-01-15

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

  17. Cadmium promotes the proliferation of triple-negative breast cancer cells through EGFR-mediated cell cycle regulation

    International Nuclear Information System (INIS)

    Wei, Zhengxi; Song, Xiulong; Shaikh, Zahir A.

    2015-01-01

    Cadmium (Cd) is a carcinogenic metal which is implicated in breast cancer by epidemiological studies. It is reported to promote breast cancer cell growth in vitro through membrane receptors. The study described here examined Cd-mediated growth of non-metastatic human breast cancer derived cells that lack receptors for estrogen, progesterone, and HER2. Treatment of triple-negative HCC 1937 cells with 0.1–0.5 μM Cd increased cell growth by activation of AKT and ERK. Accelerated cell cycle progression was achieved by increasing the levels of cyclins A, B, and E, as well as those of CDKs 1 and 2. Although triple negative cells lack estrogen receptor, they express high levels of EGFR. Therefore, further studies on HCC 1937 and another triple-negative cell line, HCC 38, were conducted using specific siRNA and an inhibitor of EGFR to determine whether EGFR was responsible for mediating the effect of Cd. The results revealed that in both cell types EGFR was not only activated upon Cd treatment, but was also essential for the downstream activation of AKT and ERK. Based on these observations, it is concluded that, in breast cancer cells lacking estrogen receptor, sub-micromolar concentration of Cd can promote cell proliferation. Furthermore, that EGFR plays a critical role in this process. - Highlights: • Sub-micromolar concentrations of Cd promote cell growth in breast cancer cells that lack ER, PR, and HER2. • The increase in cell number is not due to reduction in apoptosis. • Growth promotion involves AKT and ERK signaling and downstream stimulation of cell cycle progression. • Initiation of cell growth by Cd occurs at the cell membrane and requires the activation of EGFR.

  18. Hypoxic cell turnover in different solid tumor lines

    International Nuclear Information System (INIS)

    Ljungkvist, Anna S.E.; Bussink, Johan; Kaanders, Johannes H.A.M.; Rijken, Paulus F.J.W.; Begg, Adrian C.; Raleigh, James A.; Kogel, Albert J. van der

    2005-01-01

    Purpose: Most solid tumors contain hypoxic cells, and the amount of tumor hypoxia has been shown to have a negative impact on the outcome of radiotherapy. The efficacy of combined modality treatments depends both on the sequence and timing of the treatments. Hypoxic cell turnover in tumors may be important for optimal scheduling of combined modality treatments, especially when hypoxic cell targeting is involved. Methods and Materials: Previously we have shown that a double bioreductive hypoxic marker assay could be used to detect changes of tumor hypoxia in relation to the tumor vasculature after carbogen and hydralazine treatments. This assay was used in the current study to establish the turnover rate of hypoxic cells in three different tumor models. The first hypoxic marker, pimonidazole, was administered at variable times before tumor harvest, and the second hypoxic marker, CCI-103F, was injected at a fixed time before harvest. Hypoxic cell turnover was defined as loss of pimonidazole (first marker) relative to CCI-103F (second marker). Results: The half-life of hypoxic cell turnover was 17 h in the murine C38 colon carcinoma line, 23 h and 49 h in the human xenograft lines MEC82 and SCCNij3, respectively. Within 24 h, loss of pimonidazole-stained areas in C38 and MEC82 occurred concurrent with the appearance of pimonidazole positive cell debris in necrotic regions. In C38 and MEC82, most of the hypoxic cells had disappeared after 48 h, whereas in SCCNij3, viable cells that had been labeled with pimonidazole were still observed after 5 days. Conclusions: The present study demonstrates that the double hypoxia marker assay can be used to study changes in both the proportion of hypoxic tumor cells and their lifespan at the same time. The present study shows that large differences in hypoxic cell turnover rates may exist among tumor lines, with half-lives ranging from 17-49 h

  19. Assessment of estradiol-induced gene regulation and proliferation in an immortalized mouse immature Sertoli cell line.

    Science.gov (United States)

    Kumar, Narender; Srivastava, Swati; Burek, Malgorzata; Förster, Carola Y; Roy, Partha

    2016-03-01

    The number of Sertoli cells during proliferative phase determines the fate of the germ cells in male reproductive system. A well-characterized cell line may help in better understanding of Sertoli cell biology. Hence, the present study assessed estradiol signaling in a mouse immature Sertoli cell line (MSC-1) as an alternative model in place of primary culture of Sertoli cells. In this study, we used MSC-1 cell line, derived from 10-day old mice. The cell cycle parameters were assessed, and the expression and regulation of Sertoli cell-specific secretory genes (ABP; androgen-binding protein) and tight junction genes (claudin-5, occludin, and vimentin) in response to estradiol was studied. The results obtained suggested the presence of both estrogen receptors (ERα and ERβ) in MSC-1 cells. In vitro scratch assay and cell-cycle analysis suggested the proliferative effects of estradiol in both time- and dose-dependent manner. The gene expression profiles of ABP, claudin-5, and occludin showed biphasic regulation at low and high doses of estradiol. Analysis of signaling pathways suggested the activation of extracellular signal-regulated kinase (ERK) pathway with significantly increased pERK/ERK ratio (p<0.05). The results also suggested down regulation in the expression of mir-17 family members (mir-17, mir-20b, and mir-106a) (p<0.05). Considering the limited number of Sertoli cell lines and long-term survival inability of primary culture of Sertoli cells, MSC-1 cells could be a potential cell line for understanding the mechanisms of various cellular events in Sertoli cells. Copyright © 2016 Elsevier Inc. All rights reserved.

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

    Science.gov (United States)

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

    2015-01-02

    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 (

  1. Chemical dissection of the cell cycle: probes for cell biology and anti-cancer drug development.

    Science.gov (United States)

    Senese, S; Lo, Y C; Huang, D; Zangle, T A; Gholkar, A A; Robert, L; Homet, B; Ribas, A; Summers, M K; Teitell, M A; Damoiseaux, R; Torres, J Z

    2014-10-16

    Cancer cell proliferation relies on the ability of cancer cells to grow, transition through the cell cycle, and divide. To identify novel chemical probes for dissecting the mechanisms governing cell cycle progression and cell division, and for developing new anti-cancer therapeutics, we developed and performed a novel cancer cell-based high-throughput chemical screen for cell cycle modulators. This approach identified novel G1, S, G2, and M-phase specific inhibitors with drug-like properties and diverse chemotypes likely targeting a broad array of processes. We further characterized the M-phase inhibitors and highlight the most potent M-phase inhibitor MI-181, which targets tubulin, inhibits tubulin polymerization, activates the spindle assembly checkpoint, arrests cells in mitosis, and triggers a fast apoptotic cell death. Importantly, MI-181 has broad anti-cancer activity, especially against BRAF(V600E) melanomas.

  2. Establishment of clinically relevant radioresistant cell lines and their characteristics

    International Nuclear Information System (INIS)

    Fukumoto, Manabu; Kuwahara, Yoshikazu; Suzuki, Masatoshi

    2014-01-01

    Although radiotherapy is one of the major therapeutic modalities for eradicating malignant tumors, the existence of radioresistant cells remains one of the most critical obstacles. Standard radiotherapy consists of fractionated radiation (FR) of 2-Gy X-rays once a day, 5 days a week, over 60 Gy in total. To understand the characteristics of radioresistant cells and to develop more effective radiotherapy, we have established novel radioresistant cell lines by long-term (> 5 years) exposure to moderate doses of fractionated X-rays. While all the parental human cancer cells ceased, their radioresistant derivatives continue to proliferate with daily exposure to 2-Gy FR for more than 30 days. We have coined those cells as 'clinically relevant radioresistant' (CRR) cells. Transplanted tumors into nude mice were also CRR, indicating that CRR cell lines are powerful tools to improve cancer radiotherapy. We have shown that the suppression of autophagic cell death but not apoptosis was mainly involved in cellular radioresistance. An inhibitor of the mTOR pathway which enhances autophagy was effective to overcome CRR tumors induced in nude mice. But the underlined mechanism was not through the inhibition of autophagy. Guanine nucleotide-binding protein 1 (GBP1) over expression was necessary for maintaining the CRR phenotype, but radioresistant cells were not necessarily cancer stem cells (CSCs). Targeting GBP1 positive cancer cells may be a more efficient method in conquering cancer than targeting CSCs. Slight but significant radioresistance was acquired by 0.5 Gy/12 hrs of long-term FR exposures to parental cells for more than 31 days in accordance with cyclinD1 over expression. This acquired radioresistance (ARR) was stably maintained in the tumor cells even on 31 days after the cessation of 0.5-Gy FR. Present observations give a mechanistic insight for ARR of tumor cells through long-term FR exposure, and provide novel therapeutic targets for radiosensitization

  3. Incorrect strain information for mouse cell lines: sequential influence of misidentification on sublines

    OpenAIRE

    Uchio-Yamada, Kozue; Kasai, Fumio; Ozawa, Midori; Kohara, Arihiro

    2016-01-01

    Misidentification or cross-contamination of cell lines can cause serious issues. Human cell lines have been authenticated by short tandem repeat profiling; however, mouse cell lines have not been adequately assessed. In this study, mouse cell lines registered with the JCRB cell bank were examined by simple sequence length polymorphism (SSLP) analysis to identify their strains. Based on comparisons with 7 major inbred strains, our results revealed their strains in 80 of 90 cell lines. However,...

  4. Cysteine modified polyaniline films improve biocompatibility for two cell lines

    Energy Technology Data Exchange (ETDEWEB)

    Yslas, Edith I., E-mail: eyslas@exa.unrc.edu.ar [Departamento de Biología Molecular, Universidad Nacional de Río Cuarto, Agencia Postal Nro3, X580BYA Río Cuarto (Argentina); Cavallo, Pablo; Acevedo, Diego F.; Barbero, César A. [Departamento de Química, Universidad Nacional de Río Cuarto, Agencia Postal Nro3, X580BYA Río Cuarto (Argentina); Rivarola, Viviana A. [Departamento de Biología Molecular, Universidad Nacional de Río Cuarto, Agencia Postal Nro3, X580BYA Río Cuarto (Argentina)

    2015-06-01

    This work focuses on one of the most exciting application areas of conjugated conducting polymers, which is cell culture and tissue engineering. To improve the biocompatibility of conducting polymers we present an easy method that involves the modification of the polymer backbone using L-cysteine. In this publication, we show the synthesis of polyaniline (PANI) films supported onto Polyethylene terephthalate (PET) films, and modified using cysteine (PANI-Cys) in order to generate a biocompatible substrate for cell culture. The PANI-Cys films are characterized by Fourier Transform infrared and UV–visible spectroscopy. The changes in the hydrophilicity of the polymer films after and before the modification were tested using contact angle measurements. After modification the contact angle changes from 86° ± 1 to 90° ± 1, suggesting a more hydrophylic surface. The adhesion properties of LM2 and HaCaT cell lines on the surface of PANI-Cys films in comparison with tissue culture plastic (TCP) are studied. The PANI-Cys film shows better biocompatibility than PANI film for both cell lines. The cell morphologies on the TCP and PANI-Cys film were examined by florescence and Atomic Force Microscopy (AFM). Microscopic observations show normal cellular behavior when PANI-Cys is used as a substrate of both cell lines (HaCaT and LM2) as when they are cultured on TCP. The ability of these PANI-Cys films to support cell attachment and growth indicates their potential use as biocompatible surfaces and in tissue engineering. - Highlights: • A new surface PANI-Cys was produced on films of polyethylene terephthalate. • The relationship between surface characteristics and biocompatibility is analyzed. • The PANI-Cys film presents good biocompatibility for two cell lines.

  5. SAMHD1 controls cell cycle status, apoptosis and HIV-1 infection in monocytic THP-1 cells

    International Nuclear Information System (INIS)

    Bonifati, Serena; Daly, Michele B.; St Gelais, Corine; Kim, Sun Hee; Hollenbaugh, Joseph A.; Shepard, Caitlin; Kennedy, Edward M.; Kim, Dong-Hyun; Schinazi, Raymond F.; Kim, Baek; Wu, Li

    2016-01-01

    SAMHD1 limits HIV-1 infection in non-dividing myeloid cells by decreasing intracellular dNTP pools. HIV-1 restriction by SAMHD1 in these cells likely prevents activation of antiviral immune responses and modulates viral pathogenesis, thus highlighting a critical role of SAMHD1 in HIV-1 physiopathology. Here, we explored the function of SAMHD1 in regulating cell proliferation, cell cycle progression and apoptosis in monocytic THP-1 cells. Using the CRISPR/Cas9 technology, we generated THP-1 cells with stable SAMHD1 knockout. We found that silencing of SAMHD1 in cycling cells stimulates cell proliferation, redistributes cell cycle population in the G_1/G_0 phase and reduces apoptosis. These alterations correlated with increased dNTP levels and more efficient HIV-1 infection in dividing SAMHD1 knockout cells relative to control. Our results suggest that SAMHD1, through its dNTPase activity, affects cell proliferation, cell cycle distribution and apoptosis, and emphasize a key role of SAMHD1 in the interplay between cell cycle regulation and HIV-1 infection.

  6. SAMHD1 controls cell cycle status, apoptosis and HIV-1 infection in monocytic THP-1 cells

    Energy Technology Data Exchange (ETDEWEB)

    Bonifati, Serena [Center for Retrovirus Research, Department of Veterinary Biosciences, The Ohio State University, Columbus, OH (United States); Daly, Michele B. [Center for Drug Discovery, Department of Pediatrics, School of Medicine, Emory University, Atlanta, GA (United States); St Gelais, Corine; Kim, Sun Hee [Center for Retrovirus Research, Department of Veterinary Biosciences, The Ohio State University, Columbus, OH (United States); Hollenbaugh, Joseph A.; Shepard, Caitlin [Center for Drug Discovery, Department of Pediatrics, School of Medicine, Emory University, Atlanta, GA (United States); Kennedy, Edward M. [Department of Molecular Genetics and Microbiology, Duke University, Durham, NC (United States); Kim, Dong-Hyun [Department of Pharmacy, School of Pharmacy, Kyung-Hee University, Seoul (Korea, Republic of); Schinazi, Raymond F. [Center for Drug Discovery, Department of Pediatrics, School of Medicine, Emory University, Atlanta, GA (United States); Kim, Baek, E-mail: baek.kim@emory.edu [Center for Drug Discovery, Department of Pediatrics, School of Medicine, Emory University, Atlanta, GA (United States); Department of Pharmacy, School of Pharmacy, Kyung-Hee University, Seoul (Korea, Republic of); Wu, Li, E-mail: wu.840@osu.edu [Center for Retrovirus Research, Department of Veterinary Biosciences, The Ohio State University, Columbus, OH (United States)

    2016-08-15

    SAMHD1 limits HIV-1 infection in non-dividing myeloid cells by decreasing intracellular dNTP pools. HIV-1 restriction by SAMHD1 in these cells likely prevents activation of antiviral immune responses and modulates viral pathogenesis, thus highlighting a critical role of SAMHD1 in HIV-1 physiopathology. Here, we explored the function of SAMHD1 in regulating cell proliferation, cell cycle progression and apoptosis in monocytic THP-1 cells. Using the CRISPR/Cas9 technology, we generated THP-1 cells with stable SAMHD1 knockout. We found that silencing of SAMHD1 in cycling cells stimulates cell proliferation, redistributes cell cycle population in the G{sub 1}/G{sub 0} phase and reduces apoptosis. These alterations correlated with increased dNTP levels and more efficient HIV-1 infection in dividing SAMHD1 knockout cells relative to control. Our results suggest that SAMHD1, through its dNTPase activity, affects cell proliferation, cell cycle distribution and apoptosis, and emphasize a key role of SAMHD1 in the interplay between cell cycle regulation and HIV-1 infection.

  7. Characteristics of nobiletin-mediated alteration of gene expression in cultured cell lines

    Energy Technology Data Exchange (ETDEWEB)

    Nemoto, Kiyomitsu, E-mail: nemoto@u-shizuoka-ken.ac.jp [Department of Molecular Toxicology, School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526 (Japan); Ikeda, Ayaka; Yoshida, Chiaki; Kimura, Junko; Mori, Junki [Department of Molecular Toxicology, School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526 (Japan); Fujiwara, Hironori [Department of Anti-Dementia Functional Food Development, Research Center of Supercritical Fluid Technology, Graduate School of Engineering, Tohoku University, 6-6-7 Aoba, Aramaki, Aoba-ku, Sendai 980-8579 (Japan); Yokosuka, Akihito; Mimaki, Yoshihiro [Department of Medicinal Pharmacognosy, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji 192-0392 (Japan); Ohizumi, Yasushi [Department of Molecular Toxicology, School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526 (Japan); Department of Anti-Dementia Functional Food Development, Research Center of Supercritical Fluid Technology, Graduate School of Engineering, Tohoku University, 6-6-7 Aoba, Aramaki, Aoba-ku, Sendai 980-8579 (Japan); Laboratory of Kampo Medicines, Yokohama College of Pharmacy, 601 Matano-cho, Totsuka-ku, Yokohama 245-0066 (Japan); Degawa, Masakuni [Department of Molecular Toxicology, School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526 (Japan)

    2013-02-15

    Highlights: ► Nobiletin-mediated alterations of gene expression were examined with DNA microarrays. ► Three organ-derived cell lines were treated with 100 μM nobiletin for 24 h. ► In all cell lines, 3 endoplasmic reticulum stress-responsive genes were up-regulated. ► Some cell cycle-regulating and oxidative stress-promoting genes were down-regulated. ► These alterations may contribute to nobiletin-mediated biological effects. -- Abstract: Nobiletin, a polymethoxylated flavonoid that is highly contained in the peels of citrus fruits, exerts a wide variety of beneficial effects, including anti-proliferative effects in cancer cells, repressive effects in hyperlipidemia and hyperglycemia, and ameliorative effects in dementia at in vitro and in vivo levels. In the present study, to further understand the mechanisms of these actions of nobiletin, the nobiletin-mediated alterations of gene expression in three organ-derived cell lines – 3Y1 rat fibroblasts, HuH-7 human hepatocarcinoma cells, and SK-N-SH human neuroblastoma cells – were first examined with DNA microarrays. In all three cell lines, treatments with nobiletin (100 μM) for 24 h resulted in more than 200% increases in the expression levels of five genes, including the endoplasmic reticulum stress-responsive genes Ddit3, Trib3, and Asns, and in less than 50% decreases in the expression levels of seven genes, including the cell cycle-regulating genes Ccna2, Ccne2, and E2f8 and the oxidative stress-promoting gene Txnip. It was also confirmed that in each nobiletin-treated cell line, the levels of the DDIT3 (DNA-damage-inducible transcript 3, also known as CHOP and GADD153) and ASNS (asparagine synthetase) proteins were increased, while the level of the TXNIP (thioredoxin-interacting protein, also known as VDUP1 and TBP-2) protein was decreased. All these findings suggest that nobiletin exerts a wide variety of biological effects, at least partly, through induction of endoplasmic reticulum stress and

  8. Outside-in control -Does plant cell wall integrity regulate cell cycle progression?

    Science.gov (United States)

    Gigli-Bisceglia, Nora; Hamann, Thorsten

    2018-04-13

    During recent years it has become accepted that plant cell walls are not inert objects surrounding all plant cells but are instead highly dynamic, plastic structures. They are involved in a large number of cell biological processes and contribute actively to plant growth, development and interaction with environment. Therefore, it is not surprising that cellular processes can control plant cell wall integrity while, simultaneously, cell wall integrity can influence cellular processes. In yeast and animal cells such a bi-directional relationship also exists between the yeast/animal extra-cellular matrices and the cell cycle. In yeast, the cell wall integrity maintenance mechanism and a dedicated plasmamembrane integrity checkpoint are mediating this relationship. Recent research has yielded insights into the mechanism controlling plant cell wall metabolism during cytokinesis. However, knowledge regarding putative regulatory pathways controlling adaptive modifications in plant cell cycle activity in response to changes in the state of the plant cell wall are not yet identified. In this review, we summarize similarities and differences in regulatory mechanisms coordinating extra cellular matrices and cell cycle activity in animal and yeast cells, discuss the available evidence supporting the existence of such a mechanism in plants and suggest that the plant cell wall integrity maintenance mechanism might also control cell cycle activity in plant cells. This article is protected by copyright. All rights reserved.

  9. Phase resetting reveals network dynamics underlying a bacterial cell cycle.

    Science.gov (United States)

    Lin, Yihan; Li, Ying; Crosson, Sean; Dinner, Aaron R; Scherer, Norbert F

    2012-01-01

    Genomic and proteomic methods yield networks of biological regulatory interactions but do not provide direct insight into how those interactions are organized into functional modules, or how information flows from one module to another. In this work we introduce an approach that provides this complementary information and apply it to the bacterium Caulobacter crescentus, a paradigm for cell-cycle control. Operationally, we use an inducible promoter to express the essential transcriptional regulatory gene ctrA in a periodic, pulsed fashion. This chemical perturbation causes the population of cells to divide synchronously, and we use the resulting advance or delay of the division times of single cells to construct a phase resetting curve. We find that delay is strongly favored over advance. This finding is surprising since it does not follow from the temporal expression profile of CtrA and, in turn, simulations of existing network models. We propose a phenomenological model that suggests that the cell-cycle network comprises two distinct functional modules that oscillate autonomously and couple in a highly asymmetric fashion. These features collectively provide a new mechanism for tight temporal control of the cell cycle in C. crescentus. We discuss how the procedure can serve as the basis for a general approach for probing network dynamics, which we term chemical perturbation spectroscopy (CPS).

  10. Cellular response after irradiation: Cell cycle control and apoptosis

    International Nuclear Information System (INIS)

    Siles, E.; Valenzuela, M.T.; Nunez, M.I.; Guerrero, R.; Villalobos, M.; Ruiz de Almodovar, J.M.

    1997-01-01

    The importance of apoptotic death was assessed in a set of experiments, involving eight human tumour cell lines (breast cancer, bladder carcinoma, medulloblastoma). Various aspects of the quantitative study of apoptosis and methods based on the detection of DNA fragmentation (in situ tailing and comet assay) are described and discussed. Data obtained support the hypothesis that apoptosis is not crucial for cellular radiosensitivity and that the relationship between p53 functionality or clonogenic survival and apoptosis may bee cell type specific. (author)

  11. Monitoring cell line identity in collections of human induced pluripotent stem cells

    Directory of Open Access Journals (Sweden)

    Raquel Sarafian

    2018-04-01

    Full Text Available The ability to reprogram somatic cells into induced pluripotent stem cells (hiPSCs has led to the generation of large collections of cell lines from thousands of individuals with specific phenotypes, many of which will be shared among different research groups as invaluable tools for biomedical research. As hiPSC-based research involves extensive culture of many cell lines, the issue periodic cell line identification is particularly important to ensure that cell line identity remains accurate. Here we analyzed the different commercially available genotyping methods considering ease of in-house genotyping, cost and informativeness, and applied one of them in our workflow for hiPSC generation. We show that the chosen STR method was able to establish a unique DNA profile for each of the 35 individuals/hiPSC lines at the examined sites, as well as identify two discrepancies resulting from inadvertently exchanged samples. Our results highlight the importance of hiPSC line genotyping by an in-house method that allows periodic cell line identification and demonstrate that STR is a useful approach to supplement less frequent karyotyping and epigenetic evaluations. Keywords: Induced pluripotent stem cells, Genotyping, Cell line identification, Short tandem repeats, Quality control

  12. Detection of immunotoxicity using T-cell based cytokine reporter cell lines ('Cell Chip')

    International Nuclear Information System (INIS)

    Ringerike, Tove; Ulleraas, Erik; Voelker, Rene; Verlaan, Bert; Eikeset, Aase; Trzaska, Dominika; Adamczewska, Violetta; Olszewski, Maciej; Walczak-Drzewiecka, Aurelia; Arkusz, Joanna; Loveren, Henk van; Nilsson, Gunnar; Lovik, Martinus; Dastych, Jaroslaw; Vandebriel, Rob J.

    2005-01-01

    Safety assessment of chemicals and drugs is an important regulatory issue. The evaluation of potential adverse effects of compounds on the immune system depends today on animal experiments. An increasing demand, however, exists for in vitro alternatives. Cytokine measurement is a promising tool to evaluate chemical exposure effects on the immune system. Fortunately, this type of measurement can be performed in conjunction with in vitro exposure models. We have taken these considerations as the starting point to develop an in vitro method to efficiently screen compounds for potential immunotoxicity. The T-cell lymphoma cell line EL-4 was transfected with the regulatory sequences of interleukin (IL)-2, IL-4, IL-10, interferon (IFN)-γ or actin fused to the gene for enhanced green fluorescent protein (EGFP) in either a stabile or a destabilised form. Consequently, changes in fluorescence intensity represent changes in cytokine expression with one cell line per cytokine. We used this prototype 'Cell Chip' to test, by means of flow cytometry, the immunomodulatory potential of 13 substances and were able to detect changes in cytokine expression in 12 cases (successful for cyclosporine, rapamycin, pentamidine, thalidomide, bis(tri-n-butyltin)oxide, house dust mite allergen (Der p I), 1-chloro-2,4-dinitrobenzene, benzocaine, tolylene 2,4-diisocyanate, potassium tetrachloroplatinate, sodium dodecyl sulphate and mercuric chloride; unsuccessful for penicillin G). In conclusion, this approach seems promising for in vitro screening for potential immunotoxicity, especially when additional cell lines besides T-cells are included

  13. HDAC gene expression in pancreatic tumor cell lines following treatment with the HDAC inhibitors panobinostat (LBH589) and trichostatine (TSA).

    Science.gov (United States)

    Mehdi, Ouaïssi; Françoise, Silvy; Sofia, Costa Lima; Urs, Giger; Kevin, Zemmour; Bernard, Sastre; Igor, Sielezneff; Anabela, Cordeiro-da-Silva; Dominique, Lombardo; Eric, Mas; Ali, Ouaïssi

    2012-01-01

    In this study, the effect of LBH589 and trichostatin (TSA), a standard histone deacetylase inhibitor (HDACi) toward the growth of pancreatic cancer cell lines was studied. Thus, we examined for the first time, the HDAC family gene expression levels before and after drug treatment. Several human pancreatic cancer cell lines (Panc-1, BxPC-3, SOJ-6) and a normal human pancreatic duct immortalized epithelial cell line (HPDE/E6E7) were used as target cells. The cell growth was measured by MTT assay, cell cycle alteration, membrane phosphatidylserine exposure, DNA fragmentation, mitochondrial membrane potential loss, RT-PCR and Western blots were done using standard methods. The effect of drugs on tumor growth in vivo was studied using subcutaneous xenograft model. Except in the case of certain HDAC gene/tumor cell line couples: (SIRT1/HPDE-SOJ6/TSA- or LBH589-treated cells; LBH589-treated Panc-1 Cells; HDAC2/BxPC-3/LBH589-treated cells or TSA-treated SOJ-6-1 cells), there were no major significant changes of HDACs genes transcription in cells upon drug treatment. However, significant variation in HDACs and SIRTs protein expression levels could be seen among individual cell samples. The in vivo results showed that LBH589 formulation exhibited similar tumor reduction efficacy as the commercial drug gemcitabine. Our data demonstrate that LBH589 induced the death of pancreatic tumor cell by apoptosis. In line with its in vitro activity, LBH589 achieved a significant reduction in tumor growth in BxPC-3 pancreatic tumor cell line subcutaneous xenograft mouse model. Furthermore, exploring the impact of LBH589 on HDACs encoding genes expression revealed for the first time that some of them, depending on the cell line considered, seem to be regulated during translation. Copyright © 2012 IAP and EPC. Published by Elsevier B.V. All rights reserved.

  14. Cell cycle dependent changes in the plasma membrane organization of mammalian cells.

    Science.gov (United States)

    Denz, Manuela; Chiantia, Salvatore; Herrmann, Andreas; Mueller, Peter; Korte, Thomas; Schwarzer, Roland

    2017-03-01

    Lipid membranes are major structural elements of all eukaryotic and prokaryotic organisms. Although many aspects of their biology have been studied extensively, their dynamics and lateral heterogeneity are still not fully understood. Recently, we observed a cell-to-cell variability in the plasma membrane organization of CHO-K1 cells (Schwarzer et al., 2014). We surmised that cell cycle dependent changes of the individual cells from our unsynchronized cell population account for this phenomenon. In the present study, this hypothesis was tested. To this aim, CHO-K1 cells were arrested in different cell cycle phases by chemical treatments, and the order of their plasma membranes was determined by various fluorescent lipid analogues using fluorescence lifetime imaging microscopy. Our experiments exhibit significant differences in the membrane order of cells arrested in the G2/M or S phase compared to control cells. Our single-cell analysis also enabled the specific selection of mitotic cells, which displayed a significant increase of the membrane order compared to the control. In addition, the lipid raft marker GPImYFP was used to study the lateral organization of cell cycle arrested cells as well as mitotic cells and freely cycling samples. Again, significant differences were found between control and arrested cells and even more pronounced between control and mitotic cells. Our data demonstrate a direct correlation between cell cycle progression and plasma membrane organization, underlining that cell-to-cell heterogeneities of membrane properties have to be taken into account in cellular studies especially at the single-cell level. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Pemetrexed plus dendritic cells as third-line therapy for metastatic esophageal squamous cell carcinoma

    Directory of Open Access Journals (Sweden)

    Zhang B

    2016-06-01

    Full Text Available Bin Zhang,1,* Rui Li,2,3,* Chun-Xiao Chang,2,3 Yong Han,2,3 Sheng-Bin Shi,2,3 Jing Tian2,3 1Department of Medical Oncology, Shandong Ji Ning First People’s Hospital, 2Department of Medical Oncology, Shandong Cancer Hospital, Shandong University, Shandong 3Department of Medical Oncology, Shandong Cancer Hospital and Institute, Shandong Academy of Medical Sciences, Jinan, People’s Republic of China*These authors contributed equally to this workAbstract: This study was conducted to evaluate the toxicity and efficacy of pemetrexed plus dendritic cells (DCs when administered as third-line treatment for metastatic esophageal squamous cell carcinoma (ESCC. All patients in the study group had previously failed first-line treatment with 5-fluorouracil and cisplatin-based regimens, as well as second-line treatment with taxane-based regimens. A total of 31 patients were treated with pemetrexed (500 mg/m2 plus DCs on day 1, every 3 weeks. DCs were given for one cycle of 21 days. Thirty patients were evaluated for their response. No patient had a complete response, three patients (10.0% had a partial response, ten patients (33.3% had stable disease, and 17 patients (56.7% had progressive disease. The overall response rate was 10.0%. The median progression-free survival (PFS time was 2.9 months (95% CI, 2.7–3.2, and the median overall survival (OS time was 7.1 months (95% CI, 6.4–7.9. The median PFS and OS times among patients with high and low levels of miR-143 expression in their blood serum were significantly different: median PFS times =3.2 months (95% CI, 2.9–3.4 and 2.7 months (95% CI, 2.4–3.0, respectively (P=0.017, and median OS times =7.8 months (95% CI, 6.8–8.9 and 6.3 months (95% CI, 5.3–7.3, respectively (P=0.036. No patient experienced Grade 4 toxicity. Combined third-line treatment with pemetrexed and DCs was marginally effective and well tolerated in patients with advanced ESCC. Serum miR-143 levels are a potential

  16. Cell cycle analysis in patients with Fanconi anemia from Serbia

    Directory of Open Access Journals (Sweden)

    Ćirković Sanja

    2013-01-01

    Full Text Available Fanconi anemia (FA is a rare autosomal recessive disorder, characterized by progressive bone marrow failure, chromosomal instability and cell cycle blockage in the G2 phase. The hypersensitivity of FA cells can be additionally induced with specific alkylating agents such as diepoxybutane (DEB and mitomycin C, which is used in differential diagnosis of FA. Among 72 patients with clinical suspicion of FA, who were diagnosed at the Mother and Child Health Care Institute of Serbia “Dr Vukan Cupic” and the University Children’s Hospital (2004 - 2011, in 10 patients the diagnosis of FA was confirmed on the basis of an increased chromosome sensitivity to DEB. Five out of 10 FA patients were available for further flow cytometric analysis of cell cycle. We examined cell cycle blockage in G2 phase in untreated and with DEB treated lymphocyte cultures from FA patients and from the healthy persons, as control group. All five patients affected with FA, showed an increased DEB induced G2-phase-blockage which was over two times higher than in controls. The percentage of FA cells arrested in G2 phase was between 4,41% and 10,45% with mean value (MV of 7,76%, but in the control group this range was lower: 1,56% - 4,11% (MV: 2.84%, with no overlapping. FA patients showed an increased spontaneous arrest in G2 phase, as well, comparing to healthy controls (MV: 14,63% vs. 5,82%. Cell cycle assay of G2 phase blockage could be used as an additional diagnostic tool for confirmation of FA in patients with clinical suspicion of this disease. [Projekat Ministarstva nauke Republike Srbije, br. 173046

  17. Regulation of DNA synthesis and the cell cycle in human prostate cancer cells and lymphocytes by ovine uterine serpin

    Directory of Open Access Journals (Sweden)

    Hansen Peter J

    2008-01-01

    Full Text Available Abstract Background Uterine serpins are members of the serine proteinase inhibitor superfamily. Like some other serpins, these proteins do not appear to be functional proteinase inhibitors. The most studied member of the group, ovine uterine serpin (OvUS, inhibits proliferation of several cell types including activated lymphocytes, bovine preimplantation embryos, and cell lines for lymphoma, canine primary osteosarcoma and human prostate cancer (PC-3 cells. The goal for the present study was to evaluate the mechanism by which OvUS inhibits cell proliferation. In particular, it was tested whether inhibition of DNA synthesis in PC-3 cells involves cytotoxic actions of OvUS or the induction of apoptosis. The effect of OvUS in the production of the autocrine and angiogenic cytokine interleukin (IL-8 by PC-3 cells was also determined. Finally, it was tested whether OvUS blocks specific steps in the cell cycle using both PC-3 cells and lymphocytes. Results Recombinant OvUS blocked proliferation of PC-3 cells at concentrations as low as 8 μg/ml as determined by measurements of [3H]thymidine incorporation or ATP content per well. Treatment of PC-3 cells with OvUS did not cause cytotoxicity or apoptosis or alter interleukin-8 secretion into medium. Results from flow cytometry experiments showed that OvUS blocked the entry of PC-3 cells into S phase and the exit from G2/M phase. In addition, OvUS blocked entry of lymphocytes into S phase following activation of proliferation with phytohemagglutinin. Conclusion Results indicate that OvUS acts to block cell proliferation through disruption of the cell cycle dynamics rather than induction of cytotoxicity or apoptosis. The finding that OvUS can regulate cell proliferation makes this one of only a few serpins that function to inhibit cell growth.

  18. Nuclear receptor TLX regulates cell cycle progression in neural stem cells of the developing brain.

    Science.gov (United States)

    Li, Wenwu; Sun, Guoqiang; Yang, Su; Qu, Qiuhao; Nakashima, Kinichi; Shi, Yanhong

    2008-01-01

    TLX is an orphan nuclear receptor that is expressed exclusively in vertebrate forebrains. Although TLX is known to be expressed in embryonic brains, the mechanism by which it influences neural development remains largely unknown. We show here that TLX is expressed specifically in periventricular neural stem cells in embryonic brains. Significant thinning of neocortex was observed in embryonic d 14.5 TLX-null brains with reduced nestin labeling and decreased cell proliferation in the germinal zone. Cell cycle analysis revealed both prolonged cell cycles and increased cell cycle exit in TLX-null embryonic brains. Increased expression of a cyclin-dependent kinase inhibitor p21 and decreased expression of cyclin D1 provide a molecular basis for the deficiency of cell cycle progression in embryonic brains of TLX-null mice. Furthermore, transient knockdown of TLX by in utero electroporation led to precocious cell cycle exit and differentiation of neural stem cells followed by outward migration. Together these results indicate that TLX plays an important role in neural development by regulating cell cycle progression and exit of neural stem cells in the developing brain.

  19. Sensitivity to ionizing radiation and chemotherapeutic agents in gemcitabine-resistant human tumor cell lines

    International Nuclear Information System (INIS)

    Bree, Chris van; Kreder, Natasja Castro; Loves, Willem J.P.; Franken, Nicolaas A.P.; Peters, Godefridus J.; Haveman, Jaap

    2002-01-01

    Purpose: To determine cross-resistance to anti-tumor treatments in 2',2'difluorodeoxycytidine (dFdC, gemcitabine)-resistant human tumor cells. Methods and Materials: Human lung carcinoma cells SW-1573 (SWp) were made resistant to dFdC (SWg). Sensitivity to cisplatin (cDDP), paclitaxel, 5-fluorouracil (5-FU), methotrexate (MTX), cytarabine (ara-C), and dFdC was measured by a proliferation assay. Radiosensitivity and radioenhancement by dFdC of this cell panel and the human ovarian carcinoma cell line A2780 and its dFdC-resistant variant AG6000 were determined by clonogenic assay. Bivariate flowcytometry was performed to study cell cycle changes. Results: In the SWg, a complete deoxycytidine kinase (dCK) deficiency was found on mRNA and protein level. This was accompanied by a 10-fold decrease in dCK activity which resulted in the >1000-fold resistance to dFdC. Sensitivity to other anti-tumor drugs was not altered, except for ara-C (>100-fold resistance). Radiosensitivity was not altered in the dFdC-resistant cell lines SWg and AG6000. High concentrations (50-100 μM dFdC) induced radioenhancement in the dFdC-resistant cell lines similar to the radioenhancement obtained at lower concentrations (10 nM dFdC) in the parental lines. An early S-phase arrest was found in all cell lines after dFdC treatment where radioenhancement was achieved. Conclusions: In the dFdC-resistant lung tumor cell line SWg, the deficiency in dCK is related to the resistance to dFdC and ara-C. No cross-resistance was observed to other anti-tumor drugs used for the treatment in lung cancer. Sensitivity to ionizing radiation was not altered in two different dFdC-resistant cell lines. Resistance to dFdC does not eliminate the ability of dFdC to sensitize cells to radiation

  20. Andrographolide radiosensitizes human esophageal cancer cell line ECA109 to radiation in vitro.

    Science.gov (United States)

    Wang, Z-M; Kang, Y-H; Yang, X; Wang, J-F; Zhang, Q; Yang, B-X; Zhao, K-L; Xu, L-P; Yang, L-P; Ma, J-X; Huang, G-H; Cai, J; Sun, X-C

    2016-01-01

    To explore the radiosensitivity of andrographolide on esophageal cancer cell line ECA109. The inhibition effects of andrographolide were measured using 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium (MTT) assay. Clonogenic survival assay was used to evaluate the effects of andrographolide on the radiosensitivity of esophageal cancer cells. Immunofluorescence was employed to examine Bax expression. The changes in cell cycle distribution and apoptosis were assayed using flow cytometry. The expression of NF-κb/Cleaved-Caspase3/Bax/Bcl-2 was measured using Western blot analysis. DNA damage was detected via γ-H2AX foci counting. With a clear dose and time effects, andrographolide was found to inhibit the proliferation of esophageal cell line ECA109. The results of the clonogenic survival assay show that andrographolide could markedly enhance radiosensitivity (P Andrographolide caused a dose-dependent increase in Cleaved-Caspase3/Bax protein expression and a decrease in Bcl-2/NF-κb expression. Apoptosis in andrographolide-treated ECA-109 increased significantly compared with the apoptosis in the simple drug and radiation combined with drug groups (P andrographolide combined with radiation group increased the number of DNA double chain breaks. Andrographolide can increase the radiosensitivity of esophageal cell line ECA109. This result may be associated with the decrease in the NF-κb level and the induced apoptosis of esophageal cancer cells. © 2014 International Society for Diseases of the Esophagus.

  1. Sphere-forming cell subpopulations with cancer stem cell properties in human hepatoma cell lines

    Directory of Open Access Journals (Sweden)

    Chen Lei

    2011-06-01

    Full Text Available Abstract Background Cancer stem cells (CSCs are regarded as the cause of tumor formation and recurrence. The isolation and identification of CSCs could help to develop novel therapeutic strategies specifically targeting CSCs. Methods Human hepatoma cell lines were plated in stem cell conditioned culture system allowed for sphere forming. To evaluate the stemness characteristics of spheres, the self-renewal, proliferation, chemoresistance, tumorigenicity of the PLC/PRF/5 sphere-forming cells, and the expression levels of stem cell related proteins in the PLC/PRF/5 sphere-forming cells were assessed, comparing with the parental cells. The stem cell RT-PCR array was performed to further explore the biological properties of liver CSCs. Results The PLC/PRF/5, MHCC97H and HepG2 cells could form clonal nonadherent 3-D spheres and be serially passaged. The PLC/PRF/5 sphere-forming cells possessed a key criteria that define CSCs: persistent self-renewal, extensive proliferation, drug resistance, overexpression of liver CSCs related proteins (Oct3/4, OV6, EpCAM, CD133 and CD44. Even 500 sphere-forming cells were able to form tumors in NOD/SCID mice, and the tumor initiating capability was not decreased when spheres were passaged. Besides, downstream proteins DTX1 and Ep300 of the CSL (CBF1 in humans, Suppressor of hairless in Drosophila and LAG1 in C. elegans -independent Notch signaling pathway were highly expressed in the spheres, and a gamma-secretase inhibitor MRK003 could significantly inhibit the sphere formation ability. Conclusions Nonadherent tumor spheres from hepatoma cell lines cultured in stem cell conditioned medium possess liver CSC properties, and the CSL-independent Notch signaling pathway may play a role in liver CSCs.

  2. Importance of glutamine metabolism in leukemia cells by energy production through TCA cycle and by redox homeostasis.

    Science.gov (United States)

    Goto, Mineaki; Miwa, Hiroshi; Shikami, Masato; Tsunekawa-Imai, Norikazu; Suganuma, Kazuto; Mizuno, Shohei; Takahashi, Miyuki; Mizutani, Motonori; Hanamura, Ichiro; Nitta, Masakazu

    2014-07-01

    Some cancer cells depend on glutamine despite of pronounced glycolysis. We examined the glutamine metabolism in leukemia cells, and found that HL-60 cells most depended on glutamine in the 4 acute myelogenous leukemia (AML) cell lines examined: growth of HL-60 cells was most suppressed by glutamine deprivation and by inhibition of glutaminolysis, which was rescued by tricarboxylic acid (TCA) cycle intermediate, oxaloacetic acid. Glutamine is also involved in antioxidant defense function by increasing glutathione. Glutamine deprivation suppressed the glutathione content and elevated reactive oxygen species most evidently in HL-60 cells. Glutamine metabolism might be a therapeutic target in some leukemia.

  3. Apoptosis induction of epifriedelinol on human cervical cancer cell line

    African Journals Online (AJOL)

    Background: Present investigation evaluates the antitumor activity of epifriedelinol for the management of cervical cancer by inducing process of apoptosis. Methods: Human Cervical Cancer Cell Line, C33A and HeLa were selected for study and treated with epifriedelinol at a concentration of (50-1000 μg/ml). Cytotoxicity of ...

  4. 77 FR 5489 - Identification of Human Cell Lines Project

    Science.gov (United States)

    2012-02-03

    ... individual or species. With the advent of standardized, simple, and rapid methods for human cell line... project will undergo STR profiling, a DNA profiling method that examines/screens for STRs (DNA elements 2... distinct DNA profile and when the STR DNA fragment sizes are converted to numeric values, the DNA profiles...

  5. Antibacterial and anti-breast cancer cell line activities of ...

    African Journals Online (AJOL)

    Purpose: To evaluate the activity of extracts of Sanghuangporus sp.1 fungus against pathogenic bacteria and a breast cancer cell line. Methods: The wild fruiting body and mycelium of Sanghuangporus sp.1 were extracted with water and ethanol by ultrasonication extraction. The activity of the extracts against pathogenic ...

  6. Lineage-specific interface proteins match up the cell cycle and differentiation in embryo stem cells

    DEFF Research Database (Denmark)

    Re, Angela; Workman, Christopher; Waldron, Levi

    2014-01-01

    The shortage of molecular information on cell cycle changes along embryonic stem cell (ESC) differentiation prompts an in silico approach, which may provide a novel way to identify candidate genes or mechanisms acting in coordinating the two programs. We analyzed germ layer specific gene expression...... changes during the cell cycle and ESC differentiation by combining four human cell cycle transcriptome profiles with thirteen in vitro human ESC differentiation studies. To detect cross-talk mechanisms we then integrated the transcriptome data that displayed differential regulation with protein...... interaction data. A new class of non-transcriptionally regulated genes was identified, encoding proteins which interact systematically with proteins corresponding to genes regulated during the cell cycle or cell differentiation, and which therefore can be seen as interface proteins coordinating the two...

  7. AAVS1-Targeted Plasmid Integration in AAV Producer Cell Lines.

    Science.gov (United States)

    Luo, Yuxia; Frederick, Amy; Martin, John M; Scaria, Abraham; Cheng, Seng H; Armentano, Donna; Wadsworth, Samuel C; Vincent, Karen A

    2017-06-01

    Adeno-associated virus (AAV) producer cell lines are created via transfection of HeLaS3 cells with a single plasmid containing three components (the vector sequence, the AAV rep and cap genes, and a selectable marker gene). As this plasmid contains both the cis (Rep binding sites) and trans (Rep protein encoded by the rep gene) elements required for site-specific integration, it was predicted that plasmid integration might occur within the AAVS1 locus on human chromosome 19 (chr19). The objective of this study was to investigate whether integration in AAVS1 might be correlated with vector yield. Plasmid integration sites within several independent cell lines were assessed via Southern, fluorescence in situ hybridization (FISH) and PCR analyses. In the Southern analyses, the presence of fragments detected by both rep- and AAVS1-specific probes suggested that for several mid- and high-producing lines, plasmid DNA had integrated into the AAVS1 locus. Analysis with puroR and AAVS1-specific probes suggested that integration in AAVS1 was a more widespread phenomenon. High-producing AAV2-secreted alkaline phosphatase (SEAP) lines (masterwell 82 [MW82] and MW278) were evaluated via FISH using probes specific for the plasmid, AAVS1, and a chr19 marker. FISH analysis detected two plasmid integration sites in MW278 (neither in AAVS1), while a total of three sites were identified in MW82 (two in AAVS1). An inverse PCR assay confirmed integration within AAVS1 for several mid- and high-producing lines. In summary, the FISH, Southern, and PCR data provide evidence of site-specific integration of the plasmid within AAVS1 in several AAV producer cell lines. The data also suggest that integration in AAVS1 is a general phenomenon that is not necessarily restricted to high producers. The results also suggest that plasmid integration within the AAVS1 locus is not an absolute requirement for a high vector yield.

  8. Cellular response to 5-fluorouracil (5-FU in 5-FU-resistant colon cancer cell lines during treatment and recovery

    Directory of Open Access Journals (Sweden)

    Kravik Katherine L

    2006-05-01

    Full Text Available Abstract Background Treatment of cells with the anti-cancer drug 5-fluorouracil (5-FU causes DNA damage, which in turn affects cell proliferation and survival. Two stable wild-type TP53 5-FU-resistant cell lines, ContinB and ContinD, generated from the HCT116 colon cancer cell line, demonstrate moderate and strong resistance to 5-FU, respectively, markedly-reduced levels of 5-FU-induced apoptosis, and alterations in expression levels of a number of key cell cycle- and apoptosis-regulatory genes as a result of resistance development. The aim of the present study was to determine potential differential responses to 8 and 24-hour 5-FU treatment in these resistant cell lines. We assessed levels of 5-FU uptake into DNA, cell cycle effects and apoptosis induction throughout treatment and recovery periods for each cell line, and alterations in expression levels of DNA damage response-, cell cycle- and apoptosis-regulatory genes in response to short-term drug exposure. Results 5-FU treatment for 24 hours resulted in S phase arrests, p53 accumulation, up-regulation of p53-target genes on DNA damage response (ATF3, GADD34, GADD45A, PCNA, cell cycle-regulatory (CDKN1A, and apoptosis-regulatory pathways (FAS, and apoptosis induction in the parental and resistant cell lines. Levels of 5-FU incorporation into DNA were similar for the cell lines. The pattern of cell cycle progression during recovery demonstrated consistently that the 5-FU-resistant cell lines had the smallest S phase fractions and the largest G2(/M fractions. The strongly 5-FU-resistant ContinD cell line had the smallest S phase arrests, the lowest CDKN1A levels, and the lowest levels of 5-FU-induced apoptosis throughout the treatment and recovery periods, and the fastest recovery of exponential growth (10 days compared to the other two cell lines. The moderately 5-FU-resistant ContinB cell line had comparatively lower apoptotic levels than the parental cells during treatment and recovery

  9. A novel quantitative model of cell cycle progression based on cyclin-dependent kinases activity and population balances.

    Science.gov (United States)

    Pisu, Massimo; Concas, Alessandro; Cao, Giacomo

    2015-04-01

    Cell cycle regulates proliferative cell capacity under normal or pathologic conditions, and in general it governs all in vivo/in vitro cell growth and proliferation processes. Mathematical simulation by means of reliable and predictive models represents an important tool to interpret experiment results, to facilitate the definition of the optimal operating conditions for in vitro cultivation, or to predict the effect of a specific drug in normal/pathologic mammalian cells. Along these lines, a novel model of cell cycle progression is proposed in this work. Specifically, it is based on a population balance (PB) approach that allows one to quantitatively describe cell cycle progression through the different phases experienced by each cell of the entire population during its own life. The transition between two consecutive cell cycle phases is simulated by taking advantage of the biochemical kinetic model developed by Gérard and Goldbeter (2009) which involves cyclin-dependent kinases (CDKs) whose regulation is achieved through a variety of mechanisms that include association with cyclins and protein inhibitors, phosphorylation-dephosphorylation, and cyclin synthesis or degradation. This biochemical model properly describes the entire cell cycle of mammalian cells by maintaining a sufficient level of detail useful to identify check point for transition and to estimate phase duration required by PB. Specific examples are discussed to illustrate the ability of the proposed model to simulate the effect of drugs for in vitro trials of interest in oncology, regenerative medicine and tissue engineering. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Effect of Evodiamine on Inducing Apoptosis of Human Gastric Cancer Cell Line SGC-7901 in Vitro

    Directory of Open Access Journals (Sweden)

    LIU Shao-ping

    2014-09-01

    Full Text Available Objective: To explore the proliferation inhibition and apoptosis-inducing effect of evodiamine in human gastric cancer SGC-7901 cells. Methods: After 48 or 24 h exposure to different concentrations of evodiamine, cell proliferation was analyzed using tetrazolium blue (MTT assay while apoptosis and cell-cycle phase distribution using flow cytometry. Results: In 0.01~30.00 μg/mL range of concentrations, evodiamine inhibited the proliferation of SGC-7901 cells in dose-dependent manner, and the overall mean IC50 was (3.79±0.16 μg/mL; the apoptosis rate was increased from 3.4% to 7.0%, 13.8% and 36.3% at concentrations of 0, 0.5, 1.5 and 30 μg/mL of evodiamine, respectively; the percentage of cells accumulated in G2/M phase was increased from 17.26% to 98.92% in the cells treated with evodiamine for 24 h in 0.01~30.00 μg/mL range of concentrations. Conclusion: Evodiamine can i