WorldWideScience

Sample records for cell cycle arrests

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

    Science.gov (United States)

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

    2004-08-01

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

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

    Science.gov (United States)

    Cucinotta, Francis A.; Ren, Lei

    2004-01-01

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

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

    Science.gov (United States)

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

    2013-01-01

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

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

    Science.gov (United States)

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

    2014-12-01

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

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

    OpenAIRE

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

    2013-01-01

    Resting tumor cells represent a huge challenge during anticancer therapy due to their increased treatment resistance. TNF-related apoptosis-inducing ligand (TRAIL) is a putative future anticancer drug, currently in phases I and II clinical studies. We recently showed that TRAIL is able to target leukemia stem cell surrogates. Here, we tested the ability of TRAIL to target cell cycle-arrested tumor cells. Cell cycle arrest was induced in tumor cell lines and xenografted tumor cells in G0, G1 o...

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

    Directory of Open Access Journals (Sweden)

    Daniel J Ferullo

    2008-12-01

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

  7. 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.

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

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-03-07

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

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

    Directory of Open Access Journals (Sweden)

    Yu-Jen Chao

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

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

    Science.gov (United States)

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

    2013-08-01

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

  12. Mechanism of T-oligo-induced cell cycle arrest in Mia-Paca pancreatic cancer cells

    Science.gov (United States)

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

    2011-01-01

    DNA oligonucleotides with sequence homology to human telomeric DNA (T-oligo) induce cell cycle arrest, followed by apoptosis, senescence, or autophagy in a human cancer cell type-specific manner. T-oligo has potential as a new therapeutic strategy in oncology because of its ability to target certain types of tumor cells while sparing normal ones. In the present study, we demonstrate the T-oligo-induced S-phase cell cycle arrest in four pancreatic cancer cell lines. To further contribute to the mechanistic understanding of T-oligo, we also identify cyclin dependent kinase 2 (cdk2) as a functional mediator in the T-oligo-induced cell cycle arrest of pancreatic cancer cells. Ectopic expression of a constitutively-active cdk2 mutant abrogates T-oligo-induced cell cycle arrest in these tumor cells while knockdown of cdk2 expression alone recapitulates the T-oligo effect. Finally, we demonstrate the dispensability of T-oligo-induced ATM/ATR-mediated DNA damage response-signaling pathways, which have long been considered functional in the T-oligo signaling mechanism. PMID:21898405

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

    Science.gov (United States)

    Kwak, Hyun-Ho; Park, Bong-Soo

    2016-01-01

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

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

    Science.gov (United States)

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

    2011-07-01

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

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

    Institute of Scientific and Technical Information of China (English)

    Ke-xiu Zhu; Ya-li Cao; Bin Li; Jia Wang; Xiao-bing Han

    2009-01-01

    Objective To investigate the changes of the cell cycle regulators ATM, Chk2 and p53 and cell cycle arrest in HeLa cells after cisplatin therapy. Methods The proliferation-inhibiting rates of HeLa cells induced by eisplatin of different concentrations were measured by MTT assays. The mRNA and protein expressions of ATM, Chk2 and p53 of HeLa cells with and withont cisplatin were detected by RT-PCR and Western blot, respectively. The cell cycle analysis was conducted by flow cytometric analysis. Results Cisplatin inhibited the proliferation of HeLa cells in a dose- and time-dependent manner. The mRNA and protein expressions of ATM, Chk2 and p53 were increased in HeLa cells treated with cisplatin. The cell cycle was arrested in G2/M phase in HeLa cells treated with cisplatin. Conclusion Activation of ATM, Chk2 and p53 might be critical in determining whether cells survive or undergo apoptesis. Targeting ATM, Chk2 and p53 pathway might he a promising strategy for reversing chemoresistance to clsplatin in cervical cancer.

  17. Sophisticated framework between cell cycle arrest and apoptosis induction based on p53 dynamics.

    Science.gov (United States)

    Hamada, Hiroyuki; Tashima, Yoshihiko; Kisaka, Yu; Iwamoto, Kazunari; Hanai, Taizo; Eguchi, Yukihiro; Okamoto, Masahiro

    2009-01-01

    The tumor suppressor, p53, regulates several gene expressions that are related to the DNA repair protein, cell cycle arrest and apoptosis induction, which activates the implementation of both cell cycle arrest and induction of apoptosis. However, it is not clear how p53 specifically regulates the implementation of these functions. By applying several well-known kinetic mathematical models, we constructed a novel model that described the influence that DNA damage has on the implementation of both the G2/M phase cell cycle arrest and the intrinsic apoptosis induction via its activation of the p53 synthesis process. The model, which consisted of 32 dependent variables and 115 kinetic parameters, was used to examine interference by DNA damage in the implementation of both G2/M phase cell cycle arrest and intrinsic apoptosis induction. A low DNA damage promoted slightly the synthesis of p53, which showed a sigmoidal behavior with time. In contrast, in the case of a high DNA damage, the p53 showed an oscillation behavior with time. Regardless of the DNA damage level, there were delays in the G2/M progression. The intrinsic apoptosis was only induced in situations where grave DNA damage produced an oscillation of p53. In addition, to wreck the equilibrium between Bcl-2 and Bax the induction of apoptosis required an extreme activation of p53 produced by the oscillation dynamics, and was only implemented after the release of the G2/M phase arrest. When the p53 oscillation is observed, there is possibility that the cell implements the apoptosis induction. Moreover, in contrast to the cell cycle arrest system, the apoptosis induction system is responsible for safeguarding the system that suppresses malignant transformations. The results of these experiments will be useful in the future for elucidating of the dominant factors that determine the cell fate such as normal cell cycles, cell cycle arrest and apoptosis.

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

    Science.gov (United States)

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

    2015-01-01

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

  19. 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.

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

    Science.gov (United States)

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

    2017-01-01

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

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

    Science.gov (United States)

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

    2016-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

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

    2006-01-01

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

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

    Science.gov (United States)

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

    2016-01-20

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

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

    Science.gov (United States)

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

    2015-12-22

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

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

    Science.gov (United States)

    Liang, Liming; Bi, Wenxiang; Tian, Yuanyuan

    2016-05-01

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

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

    Institute of Scientific and Technical Information of China (English)

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

    2007-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

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

    2006-01-01

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

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

    Science.gov (United States)

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

    2016-07-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-12-01

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

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

    Institute of Scientific and Technical Information of China (English)

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

    2012-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

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

    2005-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-03-28

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

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

    Directory of Open Access Journals (Sweden)

    Bhattacharya Abhishek

    2010-03-01

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

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

    Institute of Scientific and Technical Information of China (English)

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

    2015-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Qing Li

    2013-09-01

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

  16. Hepatitis C virus infection causes cell cycle arrest at the level of initiation of mitosis.

    Science.gov (United States)

    Kannan, Rathi P; Hensley, Lucinda L; Evers, Lauren E; Lemon, Stanley M; McGivern, David R

    2011-08-01

    Chronic infection with the hepatitis C virus (HCV) is associated with increased risk for hepatocellular carcinoma (HCC). Chronic immune-mediated inflammation is likely to be an important factor in the development of HCV-associated HCC, but direct effects of HCV infection on the host cell cycle may also play a role. Although overexpression studies have revealed multiple interactions between HCV-encoded proteins and host cell cycle regulators and tumor suppressor proteins, the relevance of these observations to HCV-associated liver disease is not clear. We determined the net effect of these interactions on regulation of the cell cycle in the context of virus infection. Flow cytometry of HCV-infected carboxyfluorescein succinimidyl ester-labeled hepatoma cells indicated a slowdown in proliferation that correlated with abundance of viral antigen. A decrease in the proportions of infected cells in G(1) and S phases with an accumulation of cells in G(2)/M phase was observed, compared to mock-infected controls. Dramatic decreases in markers of mitosis, such as phospho-histone H3, in infected cells suggested a block to mitotic entry. In common with findings described in the published literature, we observed caspase 3 activation, suggesting that cell cycle arrest is associated with apoptosis. Differences were observed in patterns of cell cycle disturbance and levels of apoptosis with different strains of HCV. However, the data suggest that cell cycle arrest at the interface of G(2) and mitosis is a common feature of HCV infection.

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

    Science.gov (United States)

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

    2008-11-01

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

  18. Parthenolide Induces Apoptosis and Cell Cycle Arrest of Human 5637 Bladder Cancer Cells In Vitro

    Directory of Open Access Journals (Sweden)

    Guang Cheng

    2011-08-01

    Full Text Available Parthenolide, the principal component of sesquiterpene lactones present in medical plants such as feverfew (Tanacetum parthenium, has been reported to have anti-tumor activity. In this study, we evaluated the therapeutic potential of parthenolide against bladder cancer and its mechanism of action. Treatment of bladder cancer cells with parthenolide resulted in a significant decrease in cell viability. Parthenolide induced apoptosis through the modulation of Bcl-2 family proteins and poly (ADP-ribose polymerase degradation. Treatment with parthenolide led to G1 phase cell cycle arrest in 5637 cells by modulation of cyclin D1 and phosphorylated cyclin-dependent kinase 2. Parthenolide also inhibited the invasive ability of bladder cancer cells. These findings suggest that parthenolide could be a novel therapeutic agent for treatment of bladder cancer.

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

    Science.gov (United States)

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

    2015-01-01

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

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

    Science.gov (United States)

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

    2017-02-20

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

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

    Science.gov (United States)

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

    2015-08-14

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

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

    Institute of Scientific and Technical Information of China (English)

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

    2005-01-01

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

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

    Science.gov (United States)

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

    2015-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Hee Jin Shim

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

  5. Prolonged mechanical ventilation induces cell cycle arrest in newborn rat lung.

    Directory of Open Access Journals (Sweden)

    Andreas A Kroon

    Full Text Available RATIONALE: The molecular mechanism(s by which mechanical ventilation disrupts alveolar development, a hallmark of bronchopulmonary dysplasia, is unknown. OBJECTIVE: To determine the effect of 24 h of mechanical ventilation on lung cell cycle regulators, cell proliferation and alveolar formation in newborn rats. METHODS: Seven-day old rats were ventilated with room air for 8, 12 and 24 h using relatively moderate tidal volumes (8.5 mL.kg⁻¹. MEASUREMENT AND MAIN RESULTS: Ventilation for 24 h (h decreased the number of elastin-positive secondary crests and increased the mean linear intercept, indicating arrest of alveolar development. Proliferation (assessed by BrdU incorporation was halved after 12 h of ventilation and completely arrested after 24 h. Cyclin D1 and E1 mRNA and protein levels were decreased after 8-24 h of ventilation, while that of p27(Kip1 was significantly increased. Mechanical ventilation for 24 h also increased levels of p57(Kip2, decreased that of p16(INK4a, while the levels of p21(Waf/Cip1 and p15(INK4b were unchanged. Increased p27(Kip1 expression coincided with reduced phosphorylation of p27(Kip1 at Thr¹⁵⁷, Thr¹⁸⁷ and Thr¹⁹⁸ (p<0.05, thereby promoting its nuclear localization. Similar -but more rapid- changes in cell cycle regulators were noted when 7-day rats were ventilated with high tidal volume (40 mL.kg⁻¹ and when fetal lung epithelial cells were subjected to a continuous (17% elongation cyclic stretch. CONCLUSION: This is the first demonstration that prolonged (24 h of mechanical ventilation causes cell cycle arrest in newborn rat lungs; the arrest occurs in G₁ and is caused by increased expression and nuclear localization of Cdk inhibitor proteins (p27(Kip1, p57(Kip2 from the Kip family.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-03-09

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

  7. Quantitative model of cell cycle arrest and cellular senescence in primary human fibroblasts.

    Directory of Open Access Journals (Sweden)

    Sascha Schäuble

    Full Text Available Primary human fibroblasts in tissue culture undergo a limited number of cell divisions before entering a non-replicative "senescent" state. At early population doublings (PD, fibroblasts are proliferation-competent displaying exponential growth. During further cell passaging, an increasing number of cells become cell cycle arrested and finally senescent. This transition from proliferating to senescent cells is driven by a number of endogenous and exogenous stress factors. Here, we have developed a new quantitative model for the stepwise transition from proliferating human fibroblasts (P via reversibly cell cycle arrested (C to irreversibly arrested senescent cells (S. In this model, the transition from P to C and to S is driven by a stress function γ and a cellular stress response function F which describes the time-delayed cellular response to experimentally induced irradiation stress. The application of this model based on senescence marker quantification at the single-cell level allowed to discriminate between the cellular states P, C, and S and delivers the transition rates between the P, C and S states for different human fibroblast cell types. Model-derived quantification unexpectedly revealed significant differences in the stress response of different fibroblast cell lines. Evaluating marker specificity, we found that SA-β-Gal is a good quantitative marker for cellular senescence in WI-38 and BJ cells, however much less so in MRC-5 cells. Furthermore we found that WI-38 cells are more sensitive to stress than BJ and MRC-5 cells. Thus, the explicit separation of stress induction from the cellular stress response, and the differentiation between three cellular states P, C and S allows for the first time to quantitatively assess the response of primary human fibroblasts towards endogenous and exogenous stress during cellular ageing.

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

    Directory of Open Access Journals (Sweden)

    Neel M Fofaria

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

  9. 2-Methoxyestradiol induces cell cycle arrest and apoptosis of nasopharyngeal carcinoma cells

    Institute of Scientific and Technical Information of China (English)

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

    2004-01-01

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

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

    OpenAIRE

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

    2011-01-01

    In order to investigate the cell death-inducing effects of rotenone, a plant extract commonly used as a mitochondrial complex I inhibitor, we studied cancer cell lines with different genetic backgrounds. Rotenone inhibits cell growth through the induction of cell death and cell cycle arrest, associated with the development of mitotic catastrophe. The cell death inducer staurosporine potentiates the inhibition of cell growth by rotenone in a dose-dependent synergistic manner. The tumor suppres...

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

    Science.gov (United States)

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

    2016-01-26

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

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

    Directory of Open Access Journals (Sweden)

    Chih-Ping Hsu

    2012-01-01

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

  13. 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.

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

    Science.gov (United States)

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

    1994-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Su, Miaoxian [Biology Programme (Formally Biology Dept.), School of Life Sciences, The Chinese University of Hong Kong, Hong Kong SAR (China); Chung, Hau Yin, E-mail: anthonychung@cuhk.edu.hk [Biology Programme (Formally Biology Dept.), School of Life Sciences, The Chinese University of Hong Kong, Hong Kong SAR (China); Food and Nutritional Sciences Programme, School of Life Sciences, The Chinese University of Hong Kong, Hong Kong SAR (China); Li, Yaolan [Institute of Traditional Chinese Medicine and Natural Products, College of Pharmacy, Jinan University, Guangzhou (China); Guangdong Province Key Laboratory of Pharmacodynamic Constituents of TCM and New Drug Research, Guangzhou (China)

    2011-07-29

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

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

    Science.gov (United States)

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

    2013-04-25

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

  17. Inhibition of ultraviolet B (UVB) induced apoptosis in A431 cells by mimosine is not dependent on cell cycle arrest

    Energy Technology Data Exchange (ETDEWEB)

    Cliche, D.O.; Girouard, S.; Bissonnette, N.; Hunting, D.J. [CIHR Group in the Radiation Sciences, Faculte de Medecine, Univ. de Sherbrooke, Sherbrooke, Quebec (Canada)

    2002-07-01

    Ultraviolet (UV) radiation is a strong apoptotic trigger in many cell types. We have. previously reported that a plant amino acid, mimosine ({beta}-[N-(3-hydroxy-4-pyridone)]-{alpha}-aminopropionic acid), with a well-known reversible G1 cell cycle arrest activity can inhibit apoptosis induced by UV irradiation and RNA polymerase II blockage in human A431 cells. Here, apoptosis was measured with a fluorimetric caspase activation assay. Interestingly, the protective state was effective up to 24 h following removal of mimosine from the culture medium while cells were progressing in the cell cycle. Our results demonstrate that the protective effect of mimosine against UV-induced apoptosis can be dissociated from its G1 cell-cycle arrest activity. (author)

  18. Laminar shear stress delivers cell cycle arrest and anti-apoptosis to mesenchymal stem cells

    Institute of Scientific and Technical Information of China (English)

    Wei Luo; Wei Xiong; Jun Zhou; Zhong Fang; Wenjian Chen; Yubo Fan; Feng Li

    2011-01-01

    Biomechanical forces are emerging as critical regulators of cell function and fluid flow is a potent mechanical stimulus. Although the mechanisms of osteoblasts and osteocytes responding to fluid flow are being elucidated,little is known about how the osteoprogenitors, mesenchymal stem cells (MSCs), respond to fluid flow. Here, we examined the effects of laminar shear stress (LSS) on MSCs in vitro. MSCs from bone marrow of SpragueDawley rats were isolated, purified, and subjected to physiological levels of LSS. DNA synthesis and cell cycle were measured through [3H]thymidine and by flow cytometry,respectively, to detect the cellular proliferation. Annexin V immunostaining and Bcl-2/Bax mRNA expression were evaluated to determine the effect of LSS on MSCs apoptosis. Results showed that fluid shear stress caused a doserelated reduction of MSCs' proliferation rate with the majority of cells being arrested in the Go or G1 phase.Moreover, it was found that physiological levels of LSS exerted a potent suppression effect on MSC apoptosis, In summary, these data revealed a critical role of LSS in maintaining the quiescence of MSCs.

  19. 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.

  20. 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.

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

    Science.gov (United States)

    Castanheira, Sónia; Pérez-Martín, José

    2015-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

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

    2008-01-01

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

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

    Science.gov (United States)

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

    2011-03-01

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

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

    Science.gov (United States)

    Liu, Si-Hong; Zhu, Jian-Wei; Xu, Hui-Hua; Wang, Yan; Liu, Ya-Min; Liang, Jun-Bo; Zhang, Gui-Qiang; Cao, Di-Hua; Lin, Yang-Yang; Wu, Yong; Guo, Qi-Feng

    2016-05-01

    The cytotoxic activity of two Ru(II) complexes against A549, BEL-7402, HeLa, PC-12, SGC-7901 and SiHa cell lines was investigated by MTT method. Complexes 1 and 2 show moderate cytotoxicity toward BEL-7402 cells with an IC50 value of 53.9 ± 3.4 and 39.3 ± 2.1 μM. The effects of the complexes inducing apoptosis, cellular uptake, reactive oxygen species and mitochondrial membrane potential in BEL-7402 cells have been studied by fluorescence microscopy. The percentages of apoptotic and necrotic cells and cell cycle arrest were studied by flow cytometry. The BSA-binding behaviors were investigated by UV/visible and fluorescent spectra.

  5. Cucurbitacin B Causes Increased Radiation Sensitivity of Human Breast Cancer Cells via G2/M Cell Cycle Arrest

    Directory of Open Access Journals (Sweden)

    Suwit Duangmano

    2012-01-01

    Full Text Available Purpose. To explore the effects of cucurbitacin B on the radiation survival of human breast cancer cells and to elucidate the cellular mechanism of radiosensitization if any. Materials and Methods. Human breast carcinoma cell lines were treated with cucurbitacin B before irradiation with 0–10 Gy of C137s gamma rays. The effect of cucurbitacin B on cell-survival following irradiation was evaluated by colony-forming assay. Cell cycle distributions were investigated using flow cytometry. Real-time PCR and western blots were performed to investigate the expression of cell cycle checkpoints. Results. Cucurbitacin B inhibited breast cancer cell proliferation in a dose-dependent manner. Only MDA-MB-231 and MCF7:5C cells but not SKBR-3 cells were radiosensitized by cucurbitacin B. Flow cytometric analysis for DNA content indicated that cucurbitacin B resulted in G2/M arrest in MDA-MB-231 and MCF7:5C but not SKBR-3 cells. Moreover, Real-time PCR and western blot analysis demonstrated upregulated p21 expression before irradiation, a likely cause of the cell cycle arrest. Conclusion. Taken together, these findings suggest that cucurbitacin B causes radiosensitization of some breast cancer cells, and that cucurbitacin B induced G2/M arrest is an important mechanism. Therefore, combinations of cucurbitacin B with radiotherapy may be appropriate for experimental breast cancer treatment.

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

    Science.gov (United States)

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

    2010-01-01

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

  7. 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.

  8. Selective COX-2 inhibitor, NS-398, suppresses cellular proliferation in human hepatocellular carcinoma cell lines via cell cycle arrest

    Institute of Scientific and Technical Information of China (English)

    Ji Yeon Baek; Wonhee Hur; Jin Sang Wang; Si Hyun Bae; Seung Kew Yoon

    2007-01-01

    AIM: To investigate the growth inhibitory mechanism of NS-398, a selective cyclooxygenase-2 (COX-2) inhibitor,in two hepatocellular carcinoma (HCC) cell lines (HepG2and Huh7).METHODS: HepG2 and Huh7 cells were treated with NS-398. Its effects on cell viability, cell proliferation,cell cycles, and gene expression were respectively evaluated by water-soluble tetrazolium salt (WST-1)assay, 4'-6-diamidino-2-phenylindole (DAPI) staining,flow cytometer analysis, and Western blotting,with dimethyl sulfoxide (DMSO) as positive control.RESULTS: NS-398 showed dose- and time-dependent growth-inhibitory effects on the two cell lines.Proliferating cell nuclear antigen (PCNA) expressions in HepG2 and Huh7 cells, particularly in Huh7 cells were inhibited in a time- and dose-independent manner.NS-398 caused cell cycle arrest in the G1 phase with cell accumulation in the sub-G1 phase in HepG2 and Huh7cell lines. No evidence of apoptosis was observed in two cell lines.CONCLUSION: NS-398 reduces cell proliferation by inducing cell cycle arrest in HepG2 and Huh7 cell lines,and COX-2 inhibitors may have potent chemoprevention effects on human hepatocellular carcinoma.

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

    Science.gov (United States)

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

    2015-01-01

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

  10. Isocorydine inhibits cell proliferation in hepatocellular carcinoma cell lines by inducing G2/m cell cycle arrest and apoptosis.

    Directory of Open Access Journals (Sweden)

    Hefen Sun

    Full Text Available The treatment of human hepatocellular carcinoma (HCC cell lines with (+-isocorydine, which was isolated and purified from Papaveraceae sp. plants, resulted in a growth inhibitory effect caused by the induction of G2/M phase cell cycle arrest and apoptosis. We report that isocorydine induces G2/M phase arrest by increasing cyclin B1 and p-CDK1 expression levels, which was caused by decreasing the expression and inhibiting the activation of Cdc25C. The phosphorylation levels of Chk1 and Chk2 were increased after ICD treatment. Furthermore, G2/M arrest induced by ICD can be disrupted by Chk1 siRNA but not by Chk2 siRNA. In addition, isocorydine treatment led to a decrease in the percentage of CD133(+ PLC/PRF/5 cells. Interestingly, isocorydine treatment dramatically decreased the tumorigenicity of SMMC-7721 and Huh7 cells. These findings indicate that isocorydine might be a potential therapeutic drug for the chemotherapeutic treatment of HCC.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-05-10

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

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

    Directory of Open Access Journals (Sweden)

    Abdulrahman K Al-Asmari

    2016-01-01

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

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

    Science.gov (United States)

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

    2016-01-01

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

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

    Science.gov (United States)

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

    2014-03-01

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

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

    Science.gov (United States)

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

    2015-11-10

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

  16. Evidence that p53-mediated cell-cycle-arrest inhibits chemotherapeutic treatment of ovarian carcinomas.

    Directory of Open Access Journals (Sweden)

    Carlos S Moreno

    Full Text Available Gene expression profiles of malignant tumors surgically removed from ovarian cancer patients pre-treated with chemotherapy (neo-adjuvant prior to surgery group into two distinct clusters. One group clusters with carcinomas from patients not pre-treated with chemotherapy prior to surgery (C-L, while the other clusters with non-malignant adenomas (A-L. We show here that although the C-L cluster is preferentially associated with p53 loss-of-function (LOF mutations, the C-L cluster cancer patients display a more favorable clinical response to chemotherapy as evidenced by enhanced long-term survivorships. Our results support a model whereby p53 mediated cell-cycle-arrest/DNA repair serves as a barrier to optimal chemotherapeutic treatment of ovarian and perhaps other carcinomas and suggest that inhibition of p53 during chemotherapy may enhance clinical outcome.

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

    Directory of Open Access Journals (Sweden)

    Thamaraiselvan Rengarajan

    2013-12-01

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

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

    Science.gov (United States)

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

    2015-01-01

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

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

    Science.gov (United States)

    Adan, Aysun; Baran, Yusuf

    2016-05-01

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

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

    Science.gov (United States)

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

    2011-11-01

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

  1. Cell cycle G2/M arrest through an S phase-dependent mechanism by HIV-1 viral protein R

    Directory of Open Access Journals (Sweden)

    Liang Dong

    2010-07-01

    Full Text Available Abstract Background Cell cycle G2 arrest induced by HIV-1 Vpr is thought to benefit viral proliferation by providing an optimized cellular environment for viral replication and by skipping host immune responses. Even though Vpr-induced G2 arrest has been studied extensively, how Vpr triggers G2 arrest remains elusive. Results To examine this initiation event, we measured the Vpr effect over a single cell cycle. We found that even though Vpr stops the cell cycle at the G2/M phase, but the initiation event actually occurs in the S phase of the cell cycle. Specifically, Vpr triggers activation of Chk1 through Ser345 phosphorylation in an S phase-dependent manner. The S phase-dependent requirement of Chk1-Ser345 phosphorylation by Vpr was confirmed by siRNA gene silencing and site-directed mutagenesis. Moreover, downregulation of DNA replication licensing factors Cdt1 by siRNA significantly reduced Vpr-induced Chk1-Ser345 phosphorylation and G2 arrest. Even though hydroxyurea (HU and ultraviolet light (UV also induce Chk1-Ser345 phosphorylation in S phase under the same conditions, neither HU nor UV-treated cells were able to pass through S phase, whereas vpr-expressing cells completed S phase and stopped at the G2/M boundary. Furthermore, unlike HU/UV, Vpr promotes Chk1- and proteasome-mediated protein degradations of Cdc25B/C for G2 induction; in contrast, Vpr had little or no effect on Cdc25A protein degradation normally mediated by HU/UV. Conclusions These data suggest that Vpr induces cell cycle G2 arrest through a unique molecular mechanism that regulates host cell cycle regulation in an S-phase dependent fashion.

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

    Science.gov (United States)

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

    2017-03-01

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

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

    Directory of Open Access Journals (Sweden)

    Tereza Cristina da Silva

    2015-01-01

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

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

    Science.gov (United States)

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

    2011-03-01

    Bone morphogenetic protein 7 (BMP-7) belongs to the superfamily of transforming growth factor β-like cytokines, which can act either as tumor suppressors or as tumor promoters depending on cell type and differentiation. Our investigations focused on analyzing the effects of BMP-7 during glioma cell proliferation in vitro and in vivo. BMP-7 treatment decreased the proliferation of Gli36ΔEGFR-LITG glioma cells up to 50%through a cell cycle arrest in the G(1) phase but not by induction of apoptosis. This effect was mediated by the modulation of the expression and phosphorylation of cyclin-dependent kinase 2, cyclin-dependent kinase inhibitor p21, and downstream retinoblastoma protein. Furthermore, in vivo optical imaging of luciferase activity of Gli36ΔEGFR-LITG cells implanted intracranially into nude mice in the presence or absence of BMP-7 treatment corroborated the antiproliferative effects of this cytokine. This report clearly underlines the tumor-suppressive role of BMP-7 in glioma-derived cells. Taken together, our results indicate that manipulating the BMP/transforming growth factor β signaling cascade may serve as a new strategy for imaging-guided molecular-targeted therapy of malignant gliomas.

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

    Directory of Open Access Journals (Sweden)

    Anke Klose

    2011-03-01

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

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

    Science.gov (United States)

    Guo, Wen-jing; Chen, Tong-sheng

    2010-02-01

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

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

    Science.gov (United States)

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

    2015-09-01

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

  8. HIV-1 Vpr protein activates the NF-κB pathway to promote G2/M cell cycle arrest

    Institute of Scientific and Technical Information of China (English)

    Zhibin Liang; Ruikang Liu; Yongquan Lin; Chen Liang; Juan Tan; Wentao Qiao

    2015-01-01

    Viral protein R(Vpr) plays an important role in the replication and pathogenesis of Human immunodeficiency virus type 1(HIV-1). Some of the various functions attributed to Vpr, including the induction of G2/M cell cycle arrest, activating the NF-κB pathway, and promoting viral reverse transcription, might be interrelated. To test this hypothesis, a panel of Vpr mutants were investigated for their ability to induce G2/M arrest and to activate the NF-κB pathway. The results showed that the Vpr mutants that failed to activate NF-κB also lost the activity to induce G2/M arrest, which suggests that inducing G2/M arrest via Vpr depends at least partially on the activation of NF-κB. This latter possibility is supported by data showing that knocking down the key factors in the NF-κB pathway – p65, Rel B, IKKα, or IKKβ– partially rescued the G2/M arrest induced by Vpr.Our results suggest that the NF-κB pathway is probably involved in Vpr-induced G2/M cell cycle arrest.

  9. 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

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

    Institute of Scientific and Technical Information of China (English)

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

    2007-01-01

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

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

    Science.gov (United States)

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

    2011-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Maeva Giraudo

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

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

    Science.gov (United States)

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

    2016-10-01

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

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

    Science.gov (United States)

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

    2016-09-16

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Bin; Cai, Yingyue; Li, Yongshu [College of Life Science, Central China Normal University, Wuhan 430079, Hubei (China); Li, Jingjing [College of Life Science, Hubei Normal University, Huangshi 435002, Hubei (China); Liu, Kaiyu [College of Life Science, Central China Normal University, Wuhan 430079, Hubei (China); Li, Yi, E-mail: johnli2668@hotmail.com [College of Life Science, Central China Normal University, Wuhan 430079, Hubei (China); Bioengineering Department, Wuhan Bioengineering Institute, Wuhan 430415, Hubei (China); Yang, Yongbo, E-mail: yongboyang@mail.ccnu.edu.cn [College of Life Science, Central China Normal University, Wuhan 430079, Hubei (China)

    2013-05-25

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

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

    Directory of Open Access Journals (Sweden)

    Zhe Chen

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

  17. 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.

  18. Double Strand Breaks and Cell-Cycle Arrest Induced by the Cyanobacterial Toxin Cylindrospermopsin in HepG2 Cells

    Directory of Open Access Journals (Sweden)

    Bojana Žegura

    2013-08-01

    Full Text Available The newly emerging cyanobacterial cytotoxin cylindrospermopsin (CYN is increasingly found in surface freshwaters, worldwide. It poses a potential threat to humans after chronic exposure as it was shown to be genotoxic in a range of test systems and is potentially carcinogenic. However, the mechanisms of CYN toxicity and genotoxicity are not well understood. In the present study CYN induced formation of DNA double strand breaks (DSBs, after prolonged exposure (72 h, in human hepatoma cells, HepG2. CYN (0.1–0.5 µg/mL, 24–96 h induced morphological changes and reduced cell viability in a dose and time dependent manner. No significant increase in lactate dehydrogenase (LDH leakage could be observed after CYN exposure, indicating that the reduction in cell number was due to decreased cell proliferation and not due to cytotoxicity. This was confirmed by imunocytochemical analysis of the cell-proliferation marker Ki67. Analysis of the cell-cycle using flow-cytometry showed that CYN has an impact on the cell cycle, indicating G0/G1 arrest after 24 h and S-phase arrest after longer exposure (72 and 96 h. Our results provide new evidence that CYN is a direct acting genotoxin, causing DSBs, and these facts need to be considered in the human health risk assessment.

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

    Directory of Open Access Journals (Sweden)

    Helena Carén

    2015-11-01

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

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

    Science.gov (United States)

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

    2016-01-01

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

  1. Metformin Induces Growth Inhibition and Cell Cycle Arrest by Upregulating MicroRNA34a in Renal Cancer Cells

    Science.gov (United States)

    Xie, Wei; Wang, Lei; Sheng, Halei; Qiu, Jing; Zhang, Di; Zhang, Le; Yang, Fan; Tang, Dahai; Zhang, Kebin

    2017-01-01

    Background Metformin is a widely used biguanide drug for the treatment of type 2 diabetes. It has been revaluated as a potential anti-cancer drug with promising activity in various tumors. However, the precise mechanisms underlying the suppression of cancer cells by metformin remain not well understood. Material/Methods In this study, human renal cell carcinoma cell line ACHN was used to investigate the anti-proliferation effect of metformin. A cell counting kit-8 assay was used to detect the cell viability. The cell cycle distribution and apoptosis were analyzed by flow cytometry. The expression of cyclin D1 and p27KIP1 was detected by Western blot. The underlying mechanism involving miRNA34a was further investigated by quantitative RT-PCR and transfection with miRNA inhibitor specific for miRNA34a in ACHN, 769-P, and A498 cells. Results Metformin could significantly inhibit the proliferation of ACHN cells in a dose- and time-dependent manner. In addition, the results showed that metformin induced G0/G1 phase arrest and delayed entry into S phase in ACHN cells. It was shown that metformin downregulates the expression of cyclin D1 and increases the p27KIP1 level. Furthermore, metformin increased ACHN cell death. Lastly, miRNA34a was found to be upregulated by metformin in ACHN, 769-P, and A498 cells. Subsequently, it was demonstrated that inhibition of miRNA34a could partially attenuate the suppressive effect of metformin on renal cancer cell proliferation. Conclusions The study data revealed that metformin induced cell growth inhibition and cell cycle arrest partially by upregulating miRNA34a in renal cancer cells. PMID:28045889

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

    Science.gov (United States)

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

    2015-10-27

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

  3. Schisandrin B Induces Apoptosis and Cell Cycle Arrest of Gallbladder Cancer Cells

    Directory of Open Access Journals (Sweden)

    Shan-Shan Xiang

    2014-08-01

    Full Text Available Gallbladder cancer, with high aggressivity and extremely poor prognosis, is the most common malignancy of the bile duct. The main objective of the paper was to investigate the effects of schisandrin B (Sch B on gallbladder cancer cells and identify the mechanisms underlying its potential anticancer effects. We showed that Sch B inhibited the viability and proliferation of human gallbladder cancer cells in a dose-, time -dependent manner through MTT and colony formation assays, and decrease mitochondrial membrane potential (ΔΨm at a dose-dependent manner through flow cytometry. Flow cytometry assays also revealed G0/G1 phase arrest and apoptosis in GBC-SD and NOZ cells. Western blot analysis of Sch B-treated cells revealed the upregulation of Bax, cleaved caspase-9, cleaved caspase-3, cleaved PARP and downregulation of Bcl-2, NF-κB, cyclin D1 and CDK-4. Moreover, this drug also inhibited the tumor growth in nude mice carrying subcutaneous NOZ tumor xenografts. These data demonstrated that Sch B induced apoptosis in gallbladder cancer cells by regulating apoptosis-related protein expression, and suggests that Sch B may be a promising drug for the treatment of gallbladder cancer.

  4. Schisandrin B induces apoptosis and cell cycle arrest of gallbladder cancer cells.

    Science.gov (United States)

    Xiang, Shan-Shan; Wang, Xu-An; Li, Huai-Feng; Shu, Yi-Jun; Bao, Run-Fa; Zhang, Fei; Cao, Yang; Ye, Yuan-Yuan; Weng, Hao; Wu, Wen-Guang; Mu, Jia-Sheng; Wu, Xiang-Song; Li, Mao-Lan; Hu, Yun-Ping; Jiang, Lin; Tan, Zhu-Jun; Lu, Wei; Liu, Feng; Liu, Ying-Bin

    2014-08-27

    Gallbladder cancer, with high aggressivity and extremely poor prognosis, is the most common malignancy of the bile duct. The main objective of the paper was to investigate the effects of schisandrin B (Sch B) on gallbladder cancer cells and identify the mechanisms underlying its potential anticancer effects. We showed that Sch B inhibited the viability and proliferation of human gallbladder cancer cells in a dose-, time -dependent manner through MTT and colony formation assays, and decrease mitochondrial membrane potential (ΔΨm) at a dose-dependent manner through flow cytometry. Flow cytometry assays also revealed G0/G1 phase arrest and apoptosis in GBC-SD and NOZ cells. Western blot analysis of Sch B-treated cells revealed the upregulation of Bax, cleaved caspase-9, cleaved caspase-3, cleaved PARP and downregulation of Bcl-2, NF-κB, cyclin D1 and CDK-4. Moreover, this drug also inhibited the tumor growth in nude mice carrying subcutaneous NOZ tumor xenografts. These data demonstrated that Sch B induced apoptosis in gallbladder cancer cells by regulating apoptosis-related protein expression, and suggests that Sch B may be a promising drug for the treatment of gallbladder cancer.

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

    Science.gov (United States)

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

    2015-07-01

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

  6. Ethanolic extract of Ferula gummosa is cytotoxic against cancer cells by inducing apoptosis and cell cycle arrest.

    Science.gov (United States)

    Gudarzi, Hoda; Salimi, Mona; Irian, Saeed; Amanzadeh, Amir; Mostafapour Kandelous, Hirsa; Azadmanesh, Keyhan; Salimi, Misha

    2015-01-01

    Ferula gummosa Boiss. has medicinal applications in treating a wide range of diseases including cancer. The objective of this study was to evaluate the antiproliferative activities of the seed and gum extracts of F. gummosa as well as to study the effect of the potent extract on the induction of apoptosis and cell cycle arrest. Our results demonstrated that the ethanolic extract had the lowest IC50 value at 72 h (0.001 ± 1.2 mg/mL) in BHY cells. Moreover, flowcytometry and annexin-V analysis revealed that the ethanolic extract induced apoptosis and cell-cycle arrest in BHY cells at G1/S phase. In addition, colorimetric methods exhibited the highest amount of total phenolics and flavonoids in the aqueous and gum extracts (0.12 ± 0.037, 0.01 ± 2.51 mg/g of dry powder). Generally, the results obtained indicate that F. gummosa ethanol extract may contain effective compounds which can be used as a chemotherapeutic agent.

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

    Science.gov (United States)

    Siriwardana, Gamini; Seligman, Paul A

    2015-03-01

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

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

    Science.gov (United States)

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

    2011-10-15

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

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

    Science.gov (United States)

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

    2016-01-01

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

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

    Science.gov (United States)

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

    2013-01-01

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

  11. Selective loss of TGFbeta Smad-dependent signalling prevents cell cycle arrest and promotes invasion in oesophageal adenocarcinoma cell lines.

    Directory of Open Access Journals (Sweden)

    Benjamin A Onwuegbusi

    Full Text Available In cancer, Transforming Growth Factor beta (TGFbeta increases proliferation and promotes invasion via selective loss of signalling pathways. Oesophageal adenocarcinoma arises from Barrett's oesophagus, progresses rapidly and is usually fatal. The contribution of perturbed TGFbeta signalling in the promotion of metastasis in this disease has not been elucidated. We therefore investigated the role of TGFbeta in Barrett's associated oesophageal adenocarcinoma using a panel of cell lines (OE33, TE7, SEG, BIC, FLO. 4/5 adenocarcinoma cell lines failed to cell cycle arrest, down-regulate c-Myc or induce p21 in response to TGFbeta, and modulation of a Smad3/4 specific promoter was inhibited. These hyperproliferative adenocarcinoma cell lines displayed a TGFbeta induced increase in the expression of the extracellular matrix degrading proteinases, urokinase-type plasminogen activator (uPA and plasminogen activator inhibitor 1 (PAI-1, which correlated with an invasive cell phenotype as measured by in vitro migration, invasion and cell scattering assays. Inhibiting ERK and JNK pathways significantly reduced PAI and uPA induction and inhibited the invasive cell phenotype. These results suggest that TGFbeta Smad-dependent signalling is perturbed in Barrett's carcinogenesis, resulting in failure of growth-arrest. However, TGFbeta can promote PAI and uPA expression and invasion through MAPK pathways. These data would support a dual role for TGFbeta in oesophageal adenocarcinoma.

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

    Science.gov (United States)

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

    2014-01-01

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

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

    Science.gov (United States)

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

    2017-03-10

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

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

    Science.gov (United States)

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

    2015-10-23

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

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

    Directory of Open Access Journals (Sweden)

    Wai Wing So

    2015-08-01

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

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

    Directory of Open Access Journals (Sweden)

    Etievant Chantal

    2009-02-01

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

  17. Lectin from Agaricus Bisporus Suppresses Akt Phosphorylation and Arrests Cell Cycle Progression in Primary Human Retinal Pigment Epithelial Cells

    Directory of Open Access Journals (Sweden)

    Y. H. Cheung

    2011-05-01

    Full Text Available Anomalous retinal pigment epithelial (RPE cells have been implicated in the development of retinal diseases. Lectin from the edible mushroom Agaricus bisporus (ABL was found to inhibit growth of RPE cells. To elucidate the mechanism through which ABL inhibits RPE cell proliferation, we investigated the changes in cell proliferation-related signaling pathways and cell cycle distribution patterns. Primary human RPE cells were grown with or without the lectin (ABL supplement (20ug or 90ug/ml for three days. Phosphorylation statuses of Akt, Jnk and p38 as well as p53 expression level were investigated by Western blotting. Cellular distributions in various cell cycle phases were investigated using flow cytometry. After ABL treatment (90ug/ml, Akt was found to be hypo-phosphorylated while the expression levels of p53, phosphorylated-Jnk and phosphorylated-p38 were not altered. The amount of cells present at S phase was reduced. Our results showed that ABL hypo-phosphorylated Akt and this observation is in line with the finding that ABL could attenuate cell proliferation. As the level of p53 was not significantly altered by ABL, this suggested that the mechanism in which ABL arrested cell proliferation was independent of Akt-mediated MDM2 activation but was possibly mediated by altering G1 to S phase transition.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-07-01

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

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

    Institute of Scientific and Technical Information of China (English)

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

    2005-01-01

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

  20. Critical Role Played by Cyclin D3 in the MyoD-Mediated Arrest of Cell Cycle during Myoblast Differentiation

    OpenAIRE

    1999-01-01

    During the terminal differentiation of skeletal myoblasts, the activities of myogenic factors regulate not only tissue-specific gene expressions but also the exit from the cell cycle. The induction of cell cycle inhibitors such as p21 and pRb has been shown to play a prominent role in the growth arrest of differentiating myoblasts. Here we report that, at the onset of differentiation, activation by MyoD of the Rb, p21, and cyclin D3 genes occurs in the absence of new protein synthesis and wit...

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

    Science.gov (United States)

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

    2016-03-01

    Abnormal localization of tumor suppressor proteins is a common feature of renal cancer. Nuclear export of these tumor suppressor proteins is mediated by chromosome region maintenance-1 (CRM1). Here, we investigated the antitumor eff ects of a novel reversible inhibitor of CRM1 on renal cancer cells. We found that S109 inhibits the CRM1-mediated nuclear export of RanBP1 and reduces protein levels of CRM1. Furthermore, the inhibitory eff ect of S109 on CRM1 is reversible. Our data demonstrated that S109 signifi cantly inhibits proliferation and colony formation of renal cancer cells. Cell cycle assay showed that S109 induced G1-phase arrest, followed by the reduction of Cyclin D1 and increased expression of p53 and p21. We also found that S109 induces nuclear accumulation of tumor suppressor proteins, Foxo1 and p27. Most importantly, mutation of CRM1 at Cys528 position abolished the eff ects of S109. Taken together, our results indicate that CRM1 is a therapeutic target in renal cancer and the novel reversible CRM1 inhibitor S109 can act as a promising candidate for renal cancer therapy.

  2. The inhibition of polo kinase by matrimony maintains G2 arrest in the meiotic cell cycle.

    Directory of Open Access Journals (Sweden)

    Youbin Xiang

    2007-12-01

    Full Text Available Many meiotic systems in female animals include a lengthy arrest in G2 that separates the end of pachytene from nuclear envelope breakdown (NEB. However, the mechanisms by which a meiotic cell can arrest for long periods of time (decades in human females have remained a mystery. The Drosophila Matrimony (Mtrm protein is expressed from the end of pachytene until the completion of meiosis I. Loss-of-function mtrm mutants result in precocious NEB. Coimmunoprecipitation experiments reveal that Mtrm physically interacts with Polo kinase (Polo in vivo, and multidimensional protein identification technology mass spectrometry analysis reveals that Mtrm binds to Polo with an approximate stoichiometry of 1:1. Mutation of a Polo-Box Domain (PBD binding site in Mtrm ablates the function of Mtrm and the physical interaction of Mtrm with Polo. The meiotic defects observed in mtrm/+ heterozygotes are fully suppressed by reducing the dose of polo+, demonstrating that Mtrm acts as an inhibitor of Polo. Mtrm acts as a negative regulator of Polo during the later stages of G2 arrest. Indeed, both the repression of Polo expression until stage 11 and the inactivation of newly synthesized Polo by Mtrm until stage 13 play critical roles in maintaining and properly terminating G2 arrest. Our data suggest a model in which the eventual activation of Cdc25 by an excess of Polo at stage 13 triggers NEB and entry into prometaphase.

  3. 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.

  4. PP2A-mediated dephosphorylation of p107 plays a critical role in chondrocyte cell cycle arrest by FGF.

    Directory of Open Access Journals (Sweden)

    Victoria Kolupaeva

    Full Text Available FGF signaling inhibits chondrocyte proliferation, a cell type-specific response that is the basis for several genetic skeletal disorders caused by activating FGFR mutations. This phenomenon requires the function of the p107 and p130 members of the Rb protein family, and p107 dephosphorylation is one of the earliest distinguishing events in FGF-induced growth arrest. To determine whether p107 dephoshorylation played a critical role in the chondrocyte response to FGF, we sought to counteract this process by overexpressing in RCS chondrocytes the cyclin D1/cdk4 kinase complex. CyclinD/cdk4-expressing RCS cells became resistant to FGF-induced p107 dephosphorylation and growth arrest, and maintained significantly high levels of cyclin E/cdk2 activity and of phosphorylated p130 at later times of FGF treatment. We explored the involvement of a phosphatase in p107 dephosphorylation. Expression of the SV40 small T-Ag, which inhibits the activity of the PP2A phosphatase, or knockdown of the expression of the PP2A catalytic subunit by RNA interference prevented p107 dephosphorylation and FGF-induced growth arrest of RCS cells. Furthermore, an association between p107 and PP2A was induced by FGF treatment. Our data show that p107 dephosphorylation is a key event in FGF-induced cell cycle arrest and indicate that in chondrocytes FGF activates the PP2A phosphatase to promote p107 dephosphorylation.

  5. Down-regulation of AP-4 inhibits proliferation, induces cell cycle arrest and promotes apoptosis in human gastric cancer cells.

    Directory of Open Access Journals (Sweden)

    Xinghua Liu

    Full Text Available BACKGROUND: AP-4 belongs to the basic helix-loop-helix leucine-zipper subgroup; it controls target gene expression, regulates growth, development and cell apoptosis and has been implicated in tumorigenesis. Our previous studies indicated that AP-4 was frequently overexpressed in gastric cancers and may be associated with the poor prognosis. The purpose of this study is to examine whether silencing of AP-4 can alter biological characteristics of gastric cancer cells. METHODS: Two specific siRNAs targeting AP-4 were designed, synthesized, and transfected into gastric cancer cell lines and human normal mucosa cells. AP-4 expression was measured with real-time quantitative PCR and Western blot. Cell proliferation and chemo-sensitivity were detected by CCK-8 assay. Cell cycle assay and apoptosis assay were performed by flow cytometer, and relative expression of cell cycle regulators were detected by real-time quantitative PCR and Western blot, expression of the factors involved in the apoptosis pathway were examined in mRNA and protein level. RESULTS: The expression of AP-4 was silenced by the siRNAs transfection and the effects of AP-4 knockdown lasted 24 to 96 hrs. The siRNA-mediated silencing of AP-4 suppressed the cellular proliferation, induced apoptosis and sensitized cancer cells to anticancer drugs. In addition, the expression level of p21, p53 and Caspase-9 were increased when AP-4 was knockdown, but the expression of cyclin D1, Bcl-2 and Bcl-x(L was inhibited. It didn't induce cell cycle arrest when AP-4 was knockdown in p53 defect gastric cancer cell line Kato-III. CONCLUSIONS: These results illustrated that gene silencing of AP-4 can efficiently inhibited cell proliferation, triggered apoptosis and sensitized cancer cells to anticancer drugs in vitro, suggesting that AP-4 siRNAs mediated silencing has a potential value in the treatment of human gastric cancer.

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

    Science.gov (United States)

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

    2016-09-12

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

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

    Science.gov (United States)

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

    2016-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Huixin Tan

    2016-09-01

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

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

    Science.gov (United States)

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

    2015-01-01

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

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

    Science.gov (United States)

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

    2014-01-01

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

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

    Science.gov (United States)

    2014-01-01

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

  12. Curcumin loaded PLGA-poloxamer blend nanoparticles induce cell cycle arrest in mesothelioma cells.

    Science.gov (United States)

    Mayol, Laura; Serri, Carla; Menale, Ciro; Crispi, Stefania; Piccolo, Maria Teresa; Mita, Luigi; Giarra, Simona; Forte, Maurizio; Saija, Antonina; Biondi, Marco; Mita, Damiano Gustavo

    2015-06-01

    The pharmacological potential of curcumin (CURC) is severely restricted because of its low water solubility/absorption, short half-life and poor bioavailability. To overcome these issues, CURC-loaded nanoparticles (NPs) were produced by a double emulsion technique. In particular, NPs were made up of an amphiphilic blend of poloxamers and PLGA to confer stealth properties to the NPs to take advantage of the enhanced permeability and retention (EPR) effect. Different surface properties of NPs made up of bare PLGA and PLGA/poloxamer blend were confirmed by the different interactions of these NPs with serum proteins and also by their ability to be internalized by mesothelioma cell line. The uptake of PLGA/poloxamer NPs induces a persistent block in G0/G1 phase of the cell cycle up to 72 h, thus overcoming the drug tolerance phenomenon, normally evidenced with free CURC.

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

    Directory of Open Access Journals (Sweden)

    Fang Huang

    2016-06-01

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

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

    Science.gov (United States)

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

    1998-06-09

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

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

    Directory of Open Access Journals (Sweden)

    Sheau-Yun Yuan

    2011-01-01

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

  16. Cell cycle arrest in antheridial extract-treated root meristems of Allium cepa and Melandrium noctiflorum.

    Science.gov (United States)

    Maszewski, J; Kaźmierczak, A; Polit, J

    1998-01-01

    Previous results have demonstrated that extracts derived from maturing male sex organs of Chara tomentosa are capable of inducing profound structural and functional effects upon M-phase cells in the primary root meristems of Melandrium noctiflorum and Allium cepa. Evident changes produced by a putative factor engaged in morphogenesis of antheridial filaments are manifested by: (1) significant shortening of chromosomes, (2) decreased mitotic indices, and (3) altered proportions estimated for the prophase and telophase transit times. The present image analysis of late G2 phase nuclei in antheridial filaments of C. tomentosa supports the concepts that progressive changes of their functional activities correspond closely to the increasing proportion of condensed chromatin. Cytophotometric measurements of Feulgen-stained cell nuclei in root meristems after a prolonged incubation in antheridial extracts revealed that cells which previously divided asynchronously became preferentially arrested in G1 (M. noctiflorum) and G2 (A. cepa). The stages at which the cells arrest are supposed to counterpart restriction checkpoints that prevent the initiation of DNA synthesis and mitosis. This assumption has been confirmed by autoradiographic studies using 3H-thymidine. In terms of the "Principal Control Points" (PCP) hypothesis, the obtained results suggest that two PCPs regulate G1-->S and G2-->M transition in a nuclear structure-dependent and a species-specific manner. Although in antheridial extract-treated roots of both M. noctiflorum and A. cepa there are only slight changes in the levels of chromatin condensation, the relative proportions of G1- and G2-arrested cells and their nuclear density profiles differ, as compared with the control and carbohydrate-starved plants.

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

    Science.gov (United States)

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

    2011-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Eileen M McGowan

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

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

    Science.gov (United States)

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

    2016-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Natalia Bailon-Moscoso

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

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

    Science.gov (United States)

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

    2015-01-01

    Accumulating evidence supports the idea that secondary metabolites obtained from medicinal plants (phytometabolites) may be important contributors in the development of new chemotherapeutic agents to reduce the occurrence or recurrence of cancer. Our study focused on Dehydroleucodine (DhL), a sesquiterpene found in the provinces of Loja and Zamora-Chinchipe. In this study, we showed that DhL displayed cytostatic and cytotoxic activities on the human cerebral astrocytoma D384 cell line. With lactone isolated from Gynoxys verrucosa Wedd, a medicinal plant from Ecuador, we found that DhL induced cell death in D384 cells by triggering cell cycle arrest and inducing apoptosis and DNA damage. We further found that the cell death resulted in the increased expression of CDKN1A and BAX proteins. A marked induction of the levels of total TP73 and phosphorylated TP53, TP73, and γ-H2AX proteins was observed in D384 cells exposed to DhL, but no increase in total TP53 levels was detected. Overall these studies demonstrated the marked effect of DhL on the diminished survival of human astrocytoma cells through the induced expression of TP73 and phosphorylation of TP73 and TP53, suggesting their key roles in the tumor cell response to DhL treatment. PMID:26309132

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

    Science.gov (United States)

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

    2014-08-20

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

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

    Directory of Open Access Journals (Sweden)

    Benjamin Pfeuty

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

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

    Science.gov (United States)

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

    2013-08-01

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

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

    Directory of Open Access Journals (Sweden)

    Soma Seal

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

  6. Cytoskeleton disorder and cell cycle arrest may be associated with the alteration of protein CEP135 by microgravity

    Science.gov (United States)

    Hang, Xiaoming; Sun, Yeqing; Wu, Di; Li, Yixiao; Liu, Zhiyuan

    In the past decades, alterations in the morphology, cytoskeleton and cell cycle have been observed in cells in vitro under microgravity conditions. But the underlying mechanisms are not absolutely identified yet. Our previous study on proteomic and microRNA expression profiles of zebrafish embryos exposed to simulated-microgravity has demonstrated a serial of microgravity-sensitive molecules. Centrosomal protein of 135 kDa (CEP135) was found down-regulated, but the mRNA expression level of it was up-regulated in zebrafish embryos after simulated-microgravity. However, the functional study on CEP135 is very limited and it has not been cloned in zebrafish till now. In this study, we try to determine whether the cytoskeleton disorder and cell cycle arrest is associated with the alteration of CEP135 by microgravity. Full-length cDNA of cep135 gene was firstly cloned from mitosis phase of ZF4. The sequence was analyzed and the phylogenetic tree was constructed based on the similarity to other species. Zebrafish embryonic cell line ZF4 were exposed to simulated microgravity for 24 and 48 hours, using a rotary cell culture system (RCCS) designed by NASA. Quantitative analysis by western blot showed that CEP135 expression level was significantly decreased two times after 24 hour simulated microgravity. Cell cycle detection by flow cytometer indicated ZF4 cells were blocked in G1 phase after 24 and 48 hour simulated microgravity. Moreover, double immunostained ZF4 cells with anti-tubulin and anti-CEP135antibodies demonstrated simulated microgravity could lead to cytoskeleton disorder and CEP135 abnormality. Further investigations are currently being carried out to determine whether knockdown and over-expression of CEP135 will modulate cytoskeleton and cell cycle. In vitro data in combination within vivo results might, at least in part, explain the dramatic effects of microgravity. Key Words: microgravity; CEP135; Cytoskeleton disorder; G1 arrest; ZF4 cell line

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

    Science.gov (United States)

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

    2016-06-01

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

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

    Science.gov (United States)

    Shi, Wei; Deng, Jiagang; Tong, Rongsheng; Yang, Yong; He, Xia; Lv, Jianzhen; Wang, Hailian; Deng, Shaoping; Qi, Ping; Zhang, Dingding; Wang, Yi

    2016-04-01

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

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

    Science.gov (United States)

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

    2016-09-01

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

  10. Securinine from Phyllanthus glaucus Induces Cell Cycle Arrest and Apoptosis in Human Cervical Cancer HeLa Cells

    Science.gov (United States)

    Krauze-Baranowska, Mirosława; Ochocka, J. Renata

    2016-01-01

    Background The Securinega-type alkaloids occur in plants belonging to Euphorbiaceae family. One of the most widely distributed alkaloid of this group is securinine, which was identified next to allosecurinine in Phyllanthus glaucus (leafflower). Recently, some Securinega-type alkaloids have paid attention to its antiproliferative potency towards different cancer cells. However, the cytotoxic properties of allosecurinine have not yet been evaluated. Methods The cytotoxicity of the extract, alkaloid fraction obtained from P. glaucus, isolated securinine and allosecurinine against HeLa cells was evaluated by real-time xCELLigence system and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Apoptosis was detected by annexin V and 7-amino-actinomycin (7-AAD) staining and confirmed with fluorescent Hoechst 33342 dye. The assessment of mitochondrial membrane potential (MMP), reactive oxygen species (ROS) generation, the level of extracellular signal-regulated protein kinases 1 and 2 (ERK1/2), caspase-3/7 activity and cell cycle analysis were measured by flow cytometry. The enzymatic activity of caspase-9 was assessed by a luminometric assay. The expression of apoptosis associated genes was analyzed by real-time PCR. Results The experimental data revealed that securinine and the alkaloid fraction were significantly potent on HeLa cells growth inhibition with IC50 values of 7.02 ± 0.52 μg/ml (32.3 μM) and 25.46 ± 1.79 μg/ml, respectively. The activity of allosecurinine and Phyllanthus extract were much lower. Furthermore, our study showed that the most active securinine induced apoptosis in a dose-dependent manner in the tested cells, increased the percentage of ROS positive cells and depolarized cells as well as stimulated the activity of ERK1/2, caspase-9 and -3/7. Securinine also induced cell cycle arrest in S phase. Real-time PCR analysis showed high expression of TNFRSF genes in the cells stimulated with securinine. Conclusions Securinine

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

    Science.gov (United States)

    Hughes-Fulford, M.

    1994-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

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

    2009-01-01

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

  13. 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.

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

    Directory of Open Access Journals (Sweden)

    Wenmeng Wang

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

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

    Science.gov (United States)

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

    2013-12-01

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

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

    Directory of Open Access Journals (Sweden)

    V. Vucic

    2006-02-01

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

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

    Directory of Open Access Journals (Sweden)

    Vucic V.

    2006-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Sumit Arora

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

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

    Directory of Open Access Journals (Sweden)

    Celine J. Granier

    2014-08-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-11-11

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

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

    Science.gov (United States)

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

    2017-01-15

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

  2. Antiproliferative activity of goniothalamin enantiomers involves DNA damage, cell cycle arrest and apoptosis induction in MCF-7 and HB4a cells.

    Science.gov (United States)

    Semprebon, Simone Cristine; Marques, Lilian Areal; D'Epiro, Gláucia Fernanda Rocha; de Camargo, Elaine Aparecida; da Silva, Glenda Nicioli; Niwa, Andressa Megumi; Macedo Junior, Fernando; Mantovani, Mário Sérgio

    2015-12-25

    (R)-goniothalamin (R-GNT) is a styryl lactone that exhibits antiproliferative property against several tumor cell lines. (S)-goniothalamin (S-GNT) is the synthetic enantiomer of R-GNT, and their biological properties are poorly understood. The aim of this study was to evaluate the antiproliferative mechanisms of (R)-goniothalamin and (S)-goniothalamin in MCF-7 breast cancer cells and HB4a epithelial mammary cells. To determine the mechanisms of cell growth inhibition, we analyzed the ability of R-GNT and S-GNT to induce DNA damage, cell cycle arrest and apoptosis. Moreover, the gene expression of cell cycle components, including cyclin, CDKs and CKIs, as well as of genes involved in apoptosis and the DNA damage response were evaluated. The natural enantiomer R-GNT proved more effective in both cell lines than did the synthetic enantiomer S-GNT, inhibiting cell proliferation via cell cycle arrest and apoptosis induction, likely in response to DNA damage. The cell cycle inhibition caused by R-GNT was mediated through the upregulation of CIP/KIP cyclin-kinase inhibitors and through the downregulation of cyclins and CDKs. S-GNT, in turn, was able to cause G0/G1 cell cycle arrest and DNA damage in MCF-7 cells and apoptosis induction only in HB4a cells. Therefore, goniothalamin presents potent antiproliferative activity to breast cancer cells MCF-7. However, exposure to goniothalamin brings some undesirable effects to non-tumor cells HB4a, including genotoxicity and apoptosis induction.

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

    Science.gov (United States)

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

    2015-02-01

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

  4. Tanshinone IIA Inhibits Growth of Keratinocytes through Cell Cycle Arrest and Apoptosis: Underlying Treatment Mechanism of Psoriasis

    Directory of Open Access Journals (Sweden)

    Fu-Lun Li

    2012-01-01

    Full Text Available The aim of the present investigation was to elucidate the cellular mechanisms whereby Tanshinone IIA (Tan IIA leads to cell cycle arrest and apoptosis in vitro in keratinocytes, the target cells in psoriasis. Tan IIA inhibited proliferation of mouse keratinocytes in a dose- and time-dependent manner and induced apoptosis, resulting in S phase arrest accompanied by down-regulation of pCdk2 and cyclin A protein expression. Furthermore, Tan IIA-induced apoptosis and mitochondrial membrane potential changes were also further demonstrated by DNA fragmentation, single-cell gel electrophoresis assay (SCGE, and flow cytometry methods. Apoptosis was partially blocked by the caspase-3 inhibitor Ac-DEVD-CHO. Mitochondrial regulation of apoptosis further downstream was investigated, showing changes in the mitochondrial membrane potential, cytochrome c release into the cytoplasm, and enhanced activation of cleaved caspase-3 and Poly ADP-ribose polymerase (PARP. There was also no translocation of apoptosis-inducing factor (AIF from mitochondria to the nucleus in apoptotic keratinocytes, indicating Tan IIA-induced apoptosis occurs mainly through the caspase pathway. Our findings provide the molecular mechanisms by which Tan IIA can be used to treat psoriasis and support the traditional use of Salvia miltiorrhiza Bungee (Labiatae for psoriasis and related skin diseases.

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

    Science.gov (United States)

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

    2017-02-01

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

  6. Induced growth inhibition, cell cycle arrest and apoptosis in CD133+/CD44+ prostate cancer stem cells by flavopiridol

    Science.gov (United States)

    SONER, BURAK CEM; AKTUG, HUSEYIN; ACIKGOZ, EDA; DUZAGAC, FAHRIYE; GUVEN, UMMU; AYLA, SULE; CAL, CAG; OKTEM, GULPERI

    2014-01-01

    Flavopiridol is a flavone that inhibits several cyclin-dependent kinases and exhibits potent growth-inhibitory activity, apoptosis and G1-phase arrest in a number of human tumor cell lines. Flavopiridol is currently undergoing investigation in human clinical trials. The present study focused on the effect of flavopiridol in cell proliferation, cell cycle progression and apoptosis in prostate cancer stem cells (CSCs). Therefore, cluster of differentiation 133 (CD133)+high/CD44+high prostate CSCs were isolated from the DU145 human prostate cancer cell line. The cells were treated with flavopiridol in a dose- and time-dependent manner to determine the inhibitory effect. Cell viability and proliferation were analyzed and the efficiency of flavopiridol was assessed using the sphere-forming assay. Flavopiridol was applied to monolayer cultures of CD133high/CD44high human prostate CSCs at the following final concentrations: 100, 300, 500 and 1000 nM. The cultures were incubated for 24, 48 and 72 h. The half maximal inhibitory concentration (IC50) value of the drug was determined as 500 nM for monolayer cells. Dead cells were analyzed prior and subsequent to exposure to increasing flavopiridol doses. Annexin-V and immunofluorescence analyses were performed for the evaluation of apoptotic pathways. According to the results, flavopiridol treatment caused significant growth inhibition at 500 and 1000 nM when compared to the control at 24 h. G0/G1 analysis showed a statistically significant difference between 100 and 500 nM (P<0.005), 100 and 1000 nM (P<0.001), 300 and 1000 nM (P<0.001), and 500 and 1000 nM (P<0.001). Flavopiridol also significantly influenced the cells in the G2/M phase, particularly at high-dose treatments. Flavopiridol induced growth inhibition and apoptosis at the IC50 dose (500 nM), resulting in a significant increase in immunofluorescence staining of caspase-3, caspase-8 and p53. In conclusion, the present results indicated that flavopiridol could be a

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

    Science.gov (United States)

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

    2015-01-01

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

  8. Effects of 50 Hz pulsed electromagnetic fields on the growth and cell cycle arrest of mesenchymal stem cells: an in vitro study.

    Science.gov (United States)

    Li, Xinping; Zhang, Mingsheng; Bai, Liming; Bai, Wenfang; Xu, Weicheng; Zhu, Hongxiang

    2012-12-01

    Mesenchymal stem cells (MSCs) are capable of self-renew and multipotent differatiation which allows them to be sensitive to microenvironment is altered. Pulsed electromagnetic fields (PEMF) can affect cellular physiology of some types of cells. This study was undertaken to investigate the effects of PEMF on the growth and cell cycle arrest of MSCs expanded in vitro. To achieve this, cultured of normal rat MSCs, the treatment groups were respectively irradiated by 50 Hz PEMF at 10 mT of flux densities for 3 or 6 h. The effects of PEMF on cell proliferation, cell cycle arrest, and cell surface antigen phenotype were investigated. Our results showed that exposed MSCs had a significant proliferative capacity (P cell growth was not different (P>0.05) at an earlier phase after PEMF treatment. Exposure to PEMF had a significant increase the percentage of MSCs in G1 phase compare with the control group, with a higher percentage of cells in G1 phase exposed for 6 h then that for 3 h. At the 16th hour after treatment, PEMF had no significant effect on cell proliferation and cell cycle (P>0.05). These results suggested that PEMF enhanced MSCs proliferation with time-independent and increased the percentage of cells at the G1 phase of the cell cycle in a time-dependent manner, and the effect of PEMF on the cell proliferation and cell cycle arrest of MSCs was temporal after PEMF treatment.

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

    Science.gov (United States)

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

    2017-01-01

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

  10. Enhancement of peripheral benzodiazepine receptor ligand-induced apoptosis and cell cycle arrest of esophageal cancer cells by simultaneous inhibition of MAPK/ERK kinase.

    Science.gov (United States)

    Sutter, Andreas P; Maaser, Kerstin; Gerst, Bastian; Krahn, Antje; Zeitz, Martin; Scherübl, Hans

    2004-05-01

    Specific ligands of the peripheral benzodiazepine receptor (PBR) activate pro-apoptotic and anti-proliferative signaling pathways. Previously, we found that PBR ligands activated the p38 mitogen-activated protein kinase (MAPK) pathway in esophageal cancer cells, and that the activation of p38MAPK contributed to tumor cell apoptosis and cell cycle arrest. Here, we report that PBR ligands also activate the pro-survival MAPK/ERK kinase (MEK)/extracellular signal-regulated kinase (ERK) pathway in esophageal cancer cells, which might compromise the efficacy of PBR ligands. Hence, a combination treatment of PBR ligands and MEK inhibitors, which are emerging as promising anticancer agents, was pursued to determine whether this treatment could lead to enhanced apoptosis and cell cycle arrest. Using Western blotting we demonstrated a time- and dose-dependent phosphorylation of ERK1/2 in response to PBR ligands. Apoptosis was investigated by assessment of mitochondrial alterations and caspase-3 activity. Cell cycle arrest was measured by flow cytometric analysis of stained isolated nuclei. The inhibition of MEK/ERK with a pharmacologic inhibitor, 2'-amino-3'-methoxyflavone (PD 98059), resulted in a synergistic enhancement of PBR-ligand-induced growth inhibition, apoptosis and cell cycle arrest. Specifity of the pharmacologic inhibitor was confirmed by the use of 1,4-diamino-2,3-dicyano-1,4-bis(2-aminophenylthio)butadiene (U 0126), a second MEK/ERK inhibitor, and 1,4-diamino-2,3-dicyano-1,4-bis(methylthio)butadiene (U 0124), a structural analogue of it which does not display any affinity to MEK. Enhanced pro-apoptotic and anti-proliferative effects were observed both in KYSE-140 esophageal squamous cancer and OE-33 adenocarcinoma cells, suggesting that this effect was not cell-type specific. In addition, the PBR-mediated overexpression of the stress response gene (growth arrest and DNA-damage-inducible gene gadd153) was synergistically enhanced by MEK inhibition. This is the

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

    Science.gov (United States)

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

    2015-12-24

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

  12. Osthole Induces Cell Cycle Arrest and Inhibits Migration and Invasion via PTEN/Akt Pathways in Osteosarcoma

    Directory of Open Access Journals (Sweden)

    Lu Wang

    2016-05-01

    Full Text Available Background/Aims: Osteosarcoma is the second highest cause of cancer-related death in children and adolescents. Majority of osteosarcoma patients (90% show metastasis. Previous reports revealed that osthole showed antitumor activities via induction of apoptosis and inhibition of proliferation. However, the potential effects and detailed molecular mechanisms involved remained unclear. Methods: Cell viability was analyzed by MTT assay in osteosarcoma cell lines MG-63 and SAOS-2. Cell cycle was detected by flow cytometry. The effects of migration and invasion were evaluated by wound healing assay and transwell assays. Moreover, the level of proteins expression was determined by Western blot. Results: The cell viability of MG63 and SAOS-2 were markedly inhibited by osthole in a dose- and time-dependent manner. Cell cycle was arrested and the ability of migration and invasion was obviously reduced when cells were exposed to osthole. Moreover, enzymes involved in PTEN/Akt pathway were regulated such as PTEN and p-Akt proteins. Furthermore, osthole inhibited the tumor growth in vivo. Conclusion: Our study unraveled, for the first time, the ability of osthole to suppress osteosarcoma and elucidated the regulation of PTEN/Akt pathway as a signaling mechanism for the anti-tumor action of osthole. These findings indicate that osthole may represent a novel therapeutic strategy in the treatment of osteosarcoma.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-04-17

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

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

    Directory of Open Access Journals (Sweden)

    Katia Maalouf

    2011-02-01

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

  15. Induction of DNA damage and G2 cell cycle arrest by diepoxybutane through the activation of the Chk1-dependent pathway in mouse germ cells.

    Science.gov (United States)

    Dong, Jianyun; Wang, Zhi; Zou, Peng; Zhang, Guowei; Dong, Xiaomei; Ling, Xi; Zhang, Xi; Liu, Jinyi; Ye, Dongqing; Cao, Jia; Ao, Lin

    2015-03-16

    1,2:3,4-Diepoxybutane (DEB) is a major carcinogenic metabolite of 1,3-butadiene (BD), which has been shown to cause DNA strand breaks in cells through its potential genotoxicity. The adverse effect of DEB on male reproductive cells in response to DNA damage has not been thoroughly studied, and the related mechanism is yet to be elucidated. Using mouse spermatocyte-derived GC-2 cells, we demonstrated in the present study that DEB caused the proliferation inhibition and marked cell cycle arrest at the G2 phase but not apoptosis. DEB also induced DNA damage as evidenced by γ-H2AX expression, the comet assay, and the cytokinesis-block micronucleus assay. Meanwhile, DEB triggered the Chk1/Cdc25c/Cdc2 signal pathway, which could be abated in the presence of UCN-01 or Chk1 siRNA. GC-2 cells exposed to DEB experienced ROS generation and pretreatment of N-acetyl-l-cysteine, partly attenuated DEB-induced DNA damage, and G2 arrest. Furthermore, measurement of testicular cells showed an increased proportion of tetraploid cells in mice administrated with DEB, alongside the enhanced expression of p-Chk1. Also, the defective reproductive phenotypes, including reduced sperm motility, increased sperm malformation, and histological abnormality of testes, were observed. In conclusion, these results suggest DEB induces DNA damage and G2 cell cycle arrest by activating the Chk1-dependent pathway, while oxidative stress may be associated with eliciting toxicity in male reproductive cells.

  16. Overexpression of the promyelocytic leukemia gene suppresses growth of human bladder cancer cells by inducing G1 cell cycle arrest and apoptosis

    Institute of Scientific and Technical Information of China (English)

    HE Dalin 贺大林; NAN Xunyi 南勋义; Chang Kun-Song; WANG Yafeng 王亚峰; Chung Leland W.K.

    2003-01-01

    Objectives To examine the anti-oncogenic effects of promyelocytic leukemia (PML) on bladder cancer and to explore its molecular mechanisms of growth suppression.Methods Wild-type PML was transfected into bladder cancer cells (5637 cell) and expressed in a replication-deficient adenovirus-mediated gene delivery system and introduced into human bladder cancer cells (5637 cell) in vitro and in vivo. The effect and mechanisms of the PML gene in cell growth, clonogenicity, and tumorigenicity of bladder cancer cells were studied using in vitro and in vivo growth assays, soft agar colony-forming assay, cell cycle analysis, apoptosis assay and in vivo tumorigenicity assay.Results Overexpression of PML in 5637 cells significantly reduced their growth rate and clonogenicity on soft agar. PML suppressed bladder cancer cell growth by inducing G1 cell cycle arrest and apoptosis. Adenovirus-mediated PML (Ad-PML) significantly suppressed the tumorigenicity and growth of bladder cancer cells. Intratumoral injection of Ad-PML into tumors induced by 5637 cells dramatically suppressed their growth. Conclusions The results indicated that overexpression of PML protein may promote efficient growth inhibition of human bladder cancer cells by inducing G1 cell cycle arrest and apoptosis, and adenovirus-mediated PML (Ad-PML) expression efficiently suppresses human bladder cancer growth.

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

    Directory of Open Access Journals (Sweden)

    Ru-Wei Lin

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

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

    Science.gov (United States)

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

    2015-11-10

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

  19. Bone marrow mesenchymal stromal cells affect the cell cycle arrest effect of genotoxic agents on acute lymphocytic leukemia cells via p21 down-regulation.

    Science.gov (United States)

    Zhang, Yiran; Hu, Kaimin; Hu, Yongxian; Liu, Lizhen; Wang, Binsheng; Huang, He

    2014-09-01

    The effect of bone marrow microenvironment on the cell cycle of acute lymphocytic leukemia (ALL) and the underlying mechanism has not been elucidated. In this study, we found that in normal condition, bone marrow mesenchymal stromal cells (BM-MSCs) had no significant effect on the cell cycle and apoptosis of ALL; in the condition when the cell cycle of ALL was blocked by genotoxic agents, BM-MSCs could increase the S-phase cell ratio and decrease the G2/M phase ratio of ALL. Besides, BM-MSCs could protect ALL cells from drug-induced apoptosis. Then, we proved that BM-MSCs affect the cell cycle arrest effect of genotoxic agents on ALL cells via p21 down-regulation. Moreover, our results indicated that activation of Wnt/β-catenin and Erk pathways might be involved in the BM-MSC-induced down-regulation of p21 in ALL cells. Targeting microenvironment-related signaling pathway may therefore be a potential novel approach for ALL therapy.

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

    Science.gov (United States)

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

    2013-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-08-08

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

  2. Long Term Aggresome Accumulation Leads to DNA Damage, p53-dependent Cell Cycle Arrest, and Steric Interference in Mitosis.

    Science.gov (United States)

    Lu, Meng; Boschetti, Chiara; Tunnacliffe, Alan

    2015-11-13

    Juxtanuclear aggresomes form in cells when levels of aggregation-prone proteins exceed the capacity of the proteasome to degrade them. It is widely believed that aggresomes have a protective function, sequestering potentially damaging aggregates until these can be removed by autophagy. However, most in-cell studies have been carried out over a few days at most, and there is little information on the long term effects of aggresomes. To examine these long term effects, we created inducible, single-copy cell lines that expressed aggregation-prone polyglutamine proteins over several months. We present evidence that, as perinuclear aggresomes accumulate, they are associated with abnormal nuclear morphology and DNA double-strand breaks, resulting in cell cycle arrest via the phosphorylated p53 (Ser-15)-dependent pathway. Further analysis reveals that aggresomes can have a detrimental effect on mitosis by steric interference with chromosome alignment, centrosome positioning, and spindle formation. The incidence of apoptosis also increased in aggresome-containing cells. These severe defects developed gradually after juxtanuclear aggresome formation and were not associated with small cytoplasmic aggregates alone. Thus, our findings demonstrate that, in dividing cells, aggresomes are detrimental over the long term, rather than protective. This suggests a novel mechanism for polyglutamine-associated developmental and cell biological abnormalities, particularly those with early onset and non-neuronal pathologies.

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

    Science.gov (United States)

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

    2016-12-19

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

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

    Directory of Open Access Journals (Sweden)

    Suzana Makpol

    2011-01-01

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

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

    Science.gov (United States)

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

    2017-01-01

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

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

    Science.gov (United States)

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

    2003-12-01

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

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

    Institute of Scientific and Technical Information of China (English)

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

    2000-01-01

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

  8. Tristetraprolin induces cell cycle arrest in breast tumor cells through targeting AP-1/c-Jun and NF-κB pathway.

    Science.gov (United States)

    Xu, Li; Ning, Huan; Gu, Ling; Wang, Qinghong; Lu, Wenbao; Peng, Hui; Cui, Weiguang; Ying, Baoling; Ross, Christina R; Wilson, Gerald M; Wei, Lin; Wold, William S M; Liu, Jianguo

    2015-12-08

    The main characteristic of cancers, including breast cancer, is the ability of cancer cells to proliferate uncontrollably. However, the underlying mechanisms of cancer cell proliferation, especially those regulated by the RNA binding protein tristetraprolin (TTP), are not completely understood. In this study, we found that TTP inhibits cell proliferation in vitro and suppresses tumor growth in vivo through inducing cell cycle arrest at the S phase. Our studies demonstrate that TTP inhibits c-Jun expression through the C-terminal Zn finger and therefore increases Wee1 expression, a regulatory molecule which controls cell cycle transition from the S to the G2 phase. In contrast to the well-known function of TTP in regulating mRNA stability, TTP inhibits c-Jun expression at the level of transcription by selectively blocking NF-κB p65 nuclear translocation. Reconstitution of NF-κB p65 completely abolishes the inhibition of c-Jun transcription by TTP. Moreover, reconstitution of c-Jun in TTP-expressing breast tumor cells diminishes Wee1 overexpression and promotes cell proliferation. Our results indicate that TTP suppresses c-Jun expression that results in Wee1 induction which causes cell cycle arrest at the S phase and inhibition of cell proliferation. Our study provides a new pathway for TTP function as a tumor suppressor which could be targeted in tumor treatment.

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

    Science.gov (United States)

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

    2016-02-01

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

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

    Science.gov (United States)

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

    2017-01-01

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

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

    Science.gov (United States)

    Lee, Kyung-Mi; Yun, Ji Ho; Lee, Dong Hwa; Park, Young Gyun; Son, Kun Ho; Nho, Chu Won; Kim, Yeong Shik

    2015-04-17

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

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

    Science.gov (United States)

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

    2017-01-01

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

  13. Achyranthes aspera Root Extracts Induce Human Colon Cancer Cell (COLO-205 Death by Triggering the Mitochondrial Apoptosis Pathway and S Phase Cell Cycle Arrest

    Directory of Open Access Journals (Sweden)

    Shagun Arora

    2014-01-01

    Full Text Available Achyranthes aspera (AA has been used traditionally for the cure of various disorders. However, the action of root extracts of AA as anticancer agent and its cellular mechanism remain unclear. The aim was to screen the antitumor effect of ethanolic (EAA and aqueous (AAA root extracts on the growth of colon cancer COLO-205 cells by testing their cytotoxicity, followed by their effect on clonogenicity, migration, and induction of apoptosis. Mechanisms leading to apoptosis and cell cycle arrest were also investigated by expression studies of caspase-9, caspase-3, Bax, Bcl-2, p16, p21, and p27 genes, followed by flow cytometric analysis for cell cycle distribution. Cytotoxicity screening of AA extracts indicated greater cytotoxic activity of AAA extract against COLO-205 cells. A series of events marked by apoptosis revealed loss of cell viability, chromatin condensation, and DNA fragmentation in AAA treated cells to a greater extent. The mRNA expression levels of caspase-9, caspase-3, Bax, p16, p21, and p27 were markedly increased in the AAA treated cells, along with decreased Bcl-2 expression. The cell cycle arrest at S phase was detected by flow cytometric analysis after treatment with AAA. Overall the study signifies the aqueous extracts as a promising therapeutic candidate against cancer.

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

    Science.gov (United States)

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

    2017-03-01

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

  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 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...... an increase in the number of gamma-H2AX ‘DNA damage foci’, indicating replicative stress, which may lead to genomic instability. As the p53 tumor suppressor is an inducer of G1 arrest after DNA damage and often deregulated in cancer cells, we investigated if the growth reduction due to SSX2 expression was p53...

  17. Distinctive adaptive response to repeated exposure to hydrogen peroxide associated with upregulation of DNA repair genes and cell cycle arrest

    Directory of Open Access Journals (Sweden)

    Gloria A. Santa-Gonzalez

    2016-10-01

    Full Text Available Many environmental and physiological stresses are chronic. Thus, cells are constantly exposed to diverse types of genotoxic insults that challenge genome stability, including those that induce oxidative DNA damage. However, most in vitro studies that model cellular response to oxidative stressors employ short exposures and/or acute stress models. In this study, we tested the hypothesis that chronic and repeated exposure to a micromolar concentration of hydrogen peroxide (H2O2 could activate DNA damage responses, resulting in cellular adaptations. For this purpose, we developed an in vitro model in which we incubated mouse myoblast cells with a steady concentration of ~50 μM H2O2 for one hour daily for seven days, followed by a final challenge of a 10 or 20X higher dose of H2O2 (0.5 or 1 mM. We report that intermittent long-term exposure to this oxidative stimulus nearly eliminated cell toxicity and significantly decreased genotoxicity (in particular, a >5-fold decreased in double-strand breaks resulting from subsequent acute exposure to oxidative stress. This protection was associated with cell cycle arrest in G2/M and induction of expression of nine DNA repair genes. Together, this evidence supports an adaptive response to chronic, low-level oxidative stress that results in genomic protection and up-regulated maintenance of cellular homeostasis.

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

    Science.gov (United States)

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

    2015-09-01

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

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

    Directory of Open Access Journals (Sweden)

    Abdiryim Yusup

    2012-01-01

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

  20. Mangiferin induces cell cycle arrest at G2/M phase through ATR-Chk1 pathway in HL-60 leukemia cells.

    Science.gov (United States)

    Peng, Z G; Yao, Y B; Yang, J; Tang, Y L; Huang, X

    2015-05-12

    This study aimed to determine the effect of mangiferin on the cell cycle in HL-60 leukemia cells and expression of the cell cycle-regulatory genes Wee1, Chk1 and CDC25C and to further investigate the molecular mechanisms of the antileukemic action of mangiferin. The inhibitory effect of mangiferin on HL-60 leukemia cell proliferation was determined by the MTT assay. The impact of mangiferin on the HL-60 cell cycle was evaluated by flow cytometry. After the cells were treated with different concentrations of mangiferin, the expression levels of Wee1, Chk1 and CDC25C mRNA were determined by RT-PCR, and Western blot was used to evaluate the expression levels of cdc25c, cyclin B1, and Akt proteins. The inhibition of HL-60 cell growth by mangiferin was dose- and time-dependent. After treatment for 24 h, cells in G2/M phase increased, and G2/M phase arrest appeared with increased mRNA expression of Wee1, Chk1 and CDC25C. Mangiferin inhibited Chk1 and cdc25c mRNA expression at high concentrations and induced Wee1 mRNA expression in a dose-dependent manner. It significantly inhibited ATR, Chk1, Wee1, Akt, and ERK1/2 phosphorylation but increased cdc2 and cyclin B1 phosphorylation. Furthermore, mangiferin reduced cdc25c, cyclin B1, and Akt protein levels while inducing Wee1 protein expression. It also antagonized the phosphorylation effect of vanadate on ATR, and the phosphorylation effect of EGF on Wee1. These findings indicated that mangiferin inhibits cell cycle progression through the ATR-Chk1 stress response DNA damage pathway, leading to cell cycle arrest at G2/M phase in leukemia cells.

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

    Science.gov (United States)

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

    2008-04-01

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

  2. Programmed cell death 2 protein induces gastric cancer cell growth arrest at the early S phase of the cell cycle and apoptosis in a p53-dependent manner.

    Science.gov (United States)

    Zhang, Jian; Wei, Wei; Jin, Hui-Cheng; Ying, Rong-Chao; Zhu, A-Kao; Zhang, Fang-Jie

    2015-01-01

    Programmed cell death 2 (PDCD2) is a highly conserved nuclear protein, and aberrant PDCD2 expression alters cell apoptosis. The present study aimed to investigate PDCD2 expression in gastric cancer. Tissue specimens from 34 gastric cancer patients were collected for analysis of PDCD2 expression using immunohistochemistry, western blotting and qRT-PCR. Gastric cancer cell lines (a p53-mutated MKN28 line and a wild-type p53 MKN45 line) were used to assess the effects of PDCD2 overexpression. p53-/- nude mice were used to investigate the effect of PDCD2 on ultraviolet B (UVB)-induced skin carcinogenesis. The data showed that PDCD2 expression was reduced in gastric cancer tissue specimens, and loss of PDCD2 expression was associated with the poor survival of patients. PDCD2 expression induced gastric cancer cell growth arrest at the early S phase of the cell cycle and apoptosis. The antitumor effects of PDCD2 expression were dependent on p53 expression in gastric cancer cells. Moreover, PDCD2 expression inhibited activity of the ATM/Chk1/2/p53 signaling pathway. In addition, PDCD2 expression suppressed UVB-induced skin carcinogenesis in p53+/+ nude mice, but not in p53-/- mice. The data from the present study demonstrated that loss of PDCD2 expression could contribute to gastric cancer development and progression and that PDCD2-induced gastric cancer cell growth arrest at the early S phase of the cell cycle and apoptosis are p53-dependent.

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

    Directory of Open Access Journals (Sweden)

    Vikas Yadav

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

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

    Directory of Open Access Journals (Sweden)

    C. Chen

    2013-08-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-07-30

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

  6. Leptospermum flavescens Constituent-LF1 Causes Cell Death through the Induction of Cell Cycle Arrest and Apoptosis in Human Lung Carcinoma Cells.

    Directory of Open Access Journals (Sweden)

    Suerialoasan Navanesan

    Full Text Available Leptospermum flavescens Sm. (Myrtaceae, locally known as 'Senna makki' is a smallish tree that is widespread and recorded to naturally occur in the montane regions above 900 m a.s.l from Burma to Australia. Although the species is recorded to be used traditionally to treat various ailments, there is limited data on biological and chemical investigations of L. flavescens. The aim of the present study was to investigate and understand the ability of L. flavescens in inducing cell death in lung cancer cells. The cytotoxic potentials of the extraction yields (methanol, hexane, ethyl acetate and water extracts as wells as a semi pure fraction, LF1 were evaluated against two human non-small cell lung carcinoma cell lines (A549 and NCI-H1299 using the MTT assay. LF1 showed the greatest cytotoxic effect against both cell lines with IC50 values of 7.12 ± 0.07 and 9.62 ± 0.50 μg/ml respectively. LF1 treated cells showed a sub-G1 region in the cell cycle analysis and also caused the presence of apoptotic morphologies in cells stained with acridine orange and ethidium bromide. Treatment with LF1 manifested an apoptotic population in cells that were evaluated using the Annexin V/ propidium iodide assay. Increasing dosage of LF1 caused a rise in the presence of activated caspase-3 enzymes in treated cells. Blockage of cell cycle progression was also observed in LF1-treated cells. These findings suggest that LF1 induces apoptosis and cell cycle arrest in treated lung cancer cells. Further studies are being conducted to isolate and identify the active compound as well to better understand the mechanism involved in inducing cell death.

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

    Science.gov (United States)

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

    2015-01-28

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

  8. Wogonoside induces growth inhibition and cell cycle arrest via promoting the expression and binding activity of GATA-1 in chronic myelogenous leukemia cells.

    Science.gov (United States)

    Li, Hui; Hui, Hui; Xu, Jingyan; Yang, Hao; Zhang, Xiaoxiao; Liu, Xiao; Zhou, Yuxin; Li, Zhiyu; Guo, Qinglong; Lu, Na

    2016-06-01

    GATA-1, a zinc finger transcription factor, has been demonstrated to play a key role in the progression of leukemia. In this study, we investigate the effects of wogonoside, a naturally bioactive flavonoid derived from Scutellaria baicalensis Georgi, on cell growth and cell cycle in chronic myeloid leukemia (CML) cells, and uncover its underlying mechanisms. The experimental design comprised CML cell lines K562, imatinib-resistant K562 (K562r) cells, and primary CML cells, treated in vitro or in vivo, respectively, with wogonoside; growth and cell cycle were then evaluated. We found that wogonoside could induce growth inhibition and G0/G1 cell cycle arrest in both normal and K562r cells. Wogonoside promotes the expression of GATA-1 and facilitates the binding to methyl ethyl ketone (MEK) and p21 promoter, thus inhibiting MEK/extracellular signal-regulated kinase signaling and cell cycle checkpoint proteins, including CDK2, CDK4, cyclin A, and cyclin D1, and increasing p21 expression. Furthermore, in vivo studies showed that administration of wogonoside decreased CML cells and prolonged survival in NOD/SCID mice with CML cell xenografts. In conclusion, these results clearly revealed the inhibitory effect of wogonoside on the growth in CML cells and suggested that wogonoside may act as a promising drug for the treatment of imatinib-resistant CML.

  9. Growth inhibitory effect of KYKZL-1 on Hep G{sub 2} cells via inhibition of AA metabolites and caspase-3 pathway and cell cycle arrest

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Jing; Du, Yi-Fang; Xiao, Zhi-Yi; Pan, Li-Li; Li, Wei; Huan, Lin; Gong, Zhu-Nan [Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Science, Nanjing Normal University, Nanjing (China); Wei, Shao-Hua [College of Chemistry and Materials Science, Nanjing Normal University, Nanjing (China); Huang, Shi-Qian; Xun, Wei; Zhang, Yi; Chang, Lei-Lei; Xie, Meng-Yu [Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Science, Nanjing Normal University, Nanjing (China); Ao, Gui-Zhen [Department of Medicinal Chemistry, School of Pharmacy, Soochow University, Jiangsu (China); Cai, Jie; Qiu, Ting; Wu, Hao; Sun, Ting [Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Science, Nanjing Normal University, Nanjing (China); Xu, Guang-Lin, E-mail: xudunlop@126.com [Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Science, Nanjing Normal University, Nanjing (China); Department of Pharmacology, University of Michigan, Ann Arbor (United States)

    2014-01-01

    KYKZL-1, a newly synthesized compound with COX/5-LOX dual inhibition, was subjected to the inhibitory activity test on Hep G{sub 2} growth. We found that KYKZL-1 inhibited the growth of Hep G{sub 2} cells via inducing apoptosis. Further studies showed that KYKZL-1 activated caspase-3 through cytochrome c release from mitochondria and down regulation of Bcl-2/Bax ratio and reduced the high level of COX-2 and 5-LOX. As shown in its anti-inflammatory effect, KYKZL-1 also exhibited inhibitory effect on the PGE{sub 2} and LTB{sub 4} production in Hep G{sub 2} cells. Accordingly, exogenous addition of PGE{sub 2} or LTB{sub 4} reversed the decreases in cell viability. In addition, KYKZL-1 caused cell cycle arrest at the S–G{sub 2} checkpoint via the activation of p21{sup CIP1} protein and down-regulation of cyclin A expression. These data indicate that the growth inhibitory effect of KYKZL-1 is associated with inhibition of AA metabolites and caspase-3 pathway and cell cycle arrest. Combined with our previous findings, KYKZL-1 exhibiting COX/5-LOX inhibition may be a promising potential agent not only for inflammation control but also for cancer prevention/therapy with an enhanced gastric safety profile. - Highlights: • KYKZL-1 is designed to exhibit COX/5-LOX dual inhibition. • KYKZL-1 resulted in apoptosis of Hep G{sub 2} cells. • KYKZL-1 activated caspase-3 through cytochrome c and bcl-2/bax ratio. • KYKZL-1 caused cell cycle arrest via modulation of p21{sup CIP1} and cyclin A level.

  10. Coleusin factor exerts cytotoxic activity by inducing G0/G1 cell cycle arrest and apoptosis in human gastric cancer BGC-823 cells.

    Science.gov (United States)

    Sun, Bo; Geng, Shuo; Huang, Xiaojia; Zhu, Jin; Liu, Shu; Zhang, Yajing; Ye, Jian; Li, Yongjin; Wang, Jingze

    2011-02-01

    Coleusin factor (CF), a kind of diterpenoids, is isolated and purified from the root of a Chinese tropical plant Coleus forskohlii by our laboratory. Our previous studies have demonstrated that CF significantly inhibits growth in some kinds of cancer cell lines. Here, we found that CF remarkably inhibited growth in human gastric cancer BGC-823 cells by decreasing cell proliferation, inducing G(0)/G(1) cell cycle arrest and apoptosis. CF also decreased the mitochondrial membrane potential in BGC-823 cells. Immunoblotting analysis revealed that CF significantly decreased the expressions of cyclinD1, Bcl-2, and Bcl-x(L), increased the expressions of cytosol cytochrome c, p53, p21, and Rb. In addition, CF significantly increased the expressions and activities of caspase-3 and -9. More importantly, CF potently inhibited the growth of BGC-823 cells xenografted in athymic nude mice with negligible body weight loss and damage towards the spleen. These results indicate that CF exerts a cytotoxic effect on BGC-823 cells by inducing cell cycle arrest and apoptosis.

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

    Science.gov (United States)

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

    2014-09-01

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

  12. Characterization of sub-nuclear changes in Caenorhabditis elegans embryos exposed to brief, intermediate and long-term anoxia to analyze anoxia-induced cell cycle arrest

    Directory of Open Access Journals (Sweden)

    Trejo Jesus

    2005-12-01

    Full Text Available Abstract Background The soil nematode C. elegans survives oxygen-deprived conditions (anoxia; 2 by entering into a state of suspended animation in which cell cycle progression reversibly arrests. The majority of blastomeres of embryos exposed to anoxia arrest at interphase, prophase and metaphase. The spindle checkpoint proteins SAN-1 and MDF-2 are required for embryos to survive 24 hours of anoxia. To further investigate the mechanism of cell-cycle arrest we examined and compared sub-nuclear changes such as chromatin localization pattern, post-translational modification of histone H3, spindle microtubules, and localization of the spindle checkpoint protein SAN-1 with respect to various anoxia exposure time points. To ensure analysis of embryos exposed to anoxia and not post-anoxic recovery we fixed all embryos in an anoxia glove box chamber. Results Embryos exposed to brief periods to anoxia (30 minutes contain prophase blastomeres with chromosomes in close proximity to the nuclear membrane, condensation of interphase chromatin and metaphase blastomeres with reduced spindle microtubules density. Embryos exposed to longer periods of anoxia (1–3 days display several characteristics including interphase chromatin that is further condensed and in close proximity to the nuclear membrane, reduction in spindle structure perimeter and reduced localization of SAN-1 at the kinetochore. Additionally, we show that the spindle checkpoint protein SAN-1 is required for brief periods of anoxia-induced cell cycle arrest, thus demonstrating that this gene product is vital for early anoxia responses. In this report we suggest that the events that occur as an immediate response to brief periods of anoxia directs cell cycle arrest. Conclusion From our results we conclude that the sub-nuclear characteristics of embryos exposed to anoxia depends upon exposure time as assayed using brief (30 minutes, intermediate (6 or 12 hours or long-term (24 or 72 hours exposures

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

    Science.gov (United States)

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

    2017-01-01

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

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

    Science.gov (United States)

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

    2016-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Zohra Aloui

    2016-01-01

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

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

    Science.gov (United States)

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

    2017-02-01

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

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

    Directory of Open Access Journals (Sweden)

    Elgjo Kjell

    2009-07-01

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

  18. The microRNA 424/503 cluster reduces CDC25A expression during cell cycle arrest imposed by transforming growth factor β in mammary epithelial cells.

    Science.gov (United States)

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

    2014-12-01

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

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

    Science.gov (United States)

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

    2014-01-01

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

  20. RNA interference-mediated knockdown of brain-derived neurotrophic factor (BDNF) promotes cell cycle arrest and apoptosis in B-cell lymphoma cells.

    Science.gov (United States)

    Xia, D; Li, W; Zhang, L; Qian, H; Yao, S; Qi, X

    2014-01-01

    Brain-derived neurotrophic factor (BDNF) is a member of the neurotrophin superfamily that has been reported to be involved in a number of neurological and psychological situations. Recently, high expression level of BDNF is observed in diverse human malignancies, delineating a role of BDNF in tumorigenesis. Nevertheless, its effect on B-cell lymphoma remains unclear. In this study, RNA interference technology mediated by short hairpin RNA (shRNA) was performed to inhibit endogenous BDNF expression in B-cell lymphoma cells. Results showed that knockdown of BDNF reduced cell growth and proliferation of Raji and Ramos cells. Furthermore, down-regulation of BDNF induced a cell cycle arrest at G0/G1 phase in Raji cells, and consequently led to cell apoptosis in vitro. Meanwhile, down-regulation of Bcl-2 and up-regulation of Bax, activated caspase-3 and caspase-9 and cleaved poly (ADP-ribose) polymerase (PARP) were observed in Raji cells when endogenous BDNF was inhibited. Besides, we also found that suppression of BDNF in Raji cells increased their sensitivity to chemotherapeutic drug, 5-Fluorouracil (5-FU). Our research provides a promising therapeutic strategy for human B-cell lymphoma by targeting BDNF.

  1. A novel class I histone deacetylase inhibitor, I-7ab, induces apoptosis and arrests cell cycle progression in human colorectal cancer cells.

    Science.gov (United States)

    Yang, Liyan; Liang, Qiannan; Shen, Ke; Ma, Li; An, Na; Deng, Weiping; Fei, Zhewei; Liu, Jianwen

    2015-04-01

    Epigenetic mutations are closely associated with human diseases, especially cancers. Among them, dysregulations of histone deacetylases (HDACs) are commonly observed in human cancers. Recent years, HDAC inhibitors have been identified as promising anticancer agents; several HDAC inhibitors have been applied in clinical practice. In this study, we synthesized a novel N-hydroxyacrylamide-derived HDAC inhibitor, I-7ab, and examined its antitumor activity. Our investigations demonstrated that I-7ab exerted cytotoxicity toward and inhibited the growth of human cancer cell lines at micromolar concentrations. Among tested cells, HCT116 was the most sensitive one to the treatment of I-7ab. However, I-7ab displayed far less cytotoxicity in human normal cells. In HCT116 cells, I-7ab inhibited the expression of class I HDACs, especially that of HDAC3, and suppressed EGFR signaling pathway. With respect to the cytotoxic effect of I-7ab, it induced apoptosis via increasing the Bax/Bcl-2 ratio and suppressing the translocation of NF-κB. Other than inducing apoptosis, I-7ab inhibited the expression of cyclin B1 and thereby arrests cell cycle progression at G2/M phase. Further analyses revealed potential role of p53 and p21 in I-7ab-induced apoptosis and cell cycle arrest. According to our findings, I-7ab may serve as a lead compound for potential antitumor drugs.

  2. Metformin Induced AMPK Activation, G0/G1 Phase Cell Cycle Arrest and the Inhibition of Growth of Esophageal Squamous Cell Carcinomas In Vitro and In Vivo.

    Science.gov (United States)

    Cai, Xianbin; Hu, Xi; Tan, Xiaojun; Cheng, Weijie; Wang, Qinjia; Chen, Xiaofeng; Guan, Yinghong; Chen, Chong; Jing, Xubin

    2015-01-01

    Esophageal squamous cell carcinomas (ESCC) have become a severe threat to health and the current treatments for ESCC are frequently not effective. Recent epidemiological studies suggest that the anti-hyperglycemic agent metformin may reduce the risk of developing cancer, including ESCC, among diabetic patients. However, the antitumor effects of metformin on ESCC and the mechanisms underlying its cell cycle regulation remain elusive. The findings reported herein show that the anti-proliferative action of metformin on ESCC cell lines is partially mediated by AMPK. Moreover, we observed that metformin induced G0/G1 phase arrest accompanied by the up-regulation of p21CIP1 and p27KIP1. In vivo experiments further showed that metformin inhibited tumor growth in a ESCC xenograft model. Most importantly, the up-regulation of AMPK, p53, p21CIP1, p27KIP1 and the down-regulation of cyclinD1 are involved in the anti-tumor action of metformin in vivo. In conclusion, metformin inhibits the growth of ESCC cells both in cell cultures and in an animal model. AMPK, p53, p21CIP1, p27KIP1 and cyclinD1 are involved in the inhibition of tumor growth that is induced by metformin and cell cycle arrest in ESCC. These findings indicate that metformin has the potential for use in the treatment of ESCC.

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

    Science.gov (United States)

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

    2016-04-01

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

  4. 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

  5. Induction of apoptosis, stimulation of cell-cycle arrest and inhibition of angiogenesis make human amnion-derived cells promising sources for cell therapy of cancer.

    Science.gov (United States)

    Niknejad, Hassan; Yazdanpanah, Ghasem; Ahmadiani, Abolhassan

    2016-03-01

    Amniotic membrane (AM), the nearest layer of fetal membranes to the fetus, contains two types of cells with unique characteristics that make them excellent candidates for clinical applications. Amniotic epithelial and mesenchymal cells have low immunogenicity, anti-inflammation, anti-fibrosis and anti-bacterial properties and no ethical issues. Although amniotic cells have stem cell properties and express transcription factors specific for pluripotent stem cells, they are not tumorigenic after transplantation. In the last decade, a new line of research has been initiated with a focus on the anti-proliferative effects of amniotic epithelial and mesenchymal cells on tumor growth. Amnion-derived epithelial and mesenchymal cells inhibit tumor growth and invasion through three pathways: the induction of apoptosis, the stimulation of cell-cycle arrest and the inhibition of angiogenesis. In this review, the various aspects of the anti-cancer properties of amnion-derived cells and the underlying mechanisms are discussed with emphasis on the translation of the cell therapy of cancer from experimental into clinical practice.

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

    Science.gov (United States)

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

    2017-01-01

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

  7. Mycophenolic Acid Overcomes Imatinib and Nilotinib Resistance of Chronic Myeloid Leukemia Cells by Apoptosis or a Senescent-Like Cell Cycle Arrest

    Directory of Open Access Journals (Sweden)

    Claire Drullion

    2012-01-01

    Full Text Available We used K562 cells sensitive or generated resistant to imatinib or nilotinib to investigate their response to mycophenolic acid (MPA. MPA induced DNA damage leading to cell death with a minor contribution of apoptosis, as revealed by annexin V labeling (up to 25%. In contrast, cell cycle arrest and positive staining for senescence-associated β-galactosidase activity were detected for a large cell population (80%. MPA-induced cell death was potentialized by the inhibition of autophagy and this is associated to the upregulation of apoptosis. In contrast, senescence was neither decreased nor abrogated in autophagy deficient K562 cells. Primary CD34 cells from CML patients sensitive or resistant to imatinib or nilotinib respond to MPA although apoptosis is mainly detected. These results show that MPA is an interesting tool to overcome resistance in vitro and in vivo mainly in the evolved phase of the disease.

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

    Science.gov (United States)

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

    2016-04-01

    Cigarette smoking has been shown to be the most significant risk factor for lung cancer. Recent studies have also indicated that RNA-binding motif protein 5 (RBM5) can modulate apoptosis and suppress tumor growth. The present study focused on the role of RBM5 in the regulation of cigarette smoke extract (CSE)-induced transformation of bronchial epithelial cells into the cancerous phenotype and its mechanism of action. Herein, we exposed normal BEAS-2B cells for 8 days to varying concentrations of CSE or dimethylsulfoxide (DMSO), followed by a recovery period of 2 weeks. Next, the RBM5 protein was overexpressed in these transformed BEAS-2B cells though lentiviral infection. Later, the morphological changes, cell proliferation, cell cycle, apoptosis, invasion and migration were assessed. In addition, we analyzed the role of RBM5 in xenograft growth. The expression of RBM5 along with the genes related to cell cycle regulation, apoptosis and invasion were also examined. Finally, our results revealed that BEAS-2B cells exposed to 100 µg/ml CSE acquired phenotypic changes and formed tumors in nude mice, indicative of their cancerous transformation and had reduced RBM5 expression. Subsequent overexpression of RBM5 in these cells significantly inhibited their proliferation, induced G1/S arrest, triggered apoptosis and inhibited their invasion and migration, including xenograft growth. Thus, we established an in vitro model of CSE-induced cancerous transformation and concluded that RBM5 overexpression inhibited the growth of these transformed cells through cell cycle arrest and induction of apoptosis. Therefore, our study suggests the importance of RBM5 in the pathogenesis of smoking-related cancer.

  9. Induction of cell cycle arrest in human MCF-7 breast cancer cells by cis-stilbene derivatives related to VIOXX.

    NARCIS (Netherlands)

    Sangjun, S.; de Jong, E.; Nijmeijer, S.; Mutarapat, T.; Ruchirawat, S.; van den Berg, M.; van Duursen, M.B.M.

    2009-01-01

    In our present study, 12 new cis-stilbene derivatives (CRI-1-CRI-13) related to VIOXX((R)) were synthesized and studied for their inhibitory effects on cell cycle progression and anti-estrogenicity in human adenoma breast cancer MCF-7 cells. Based on the different substituents in the cis-stilbene mo

  10. Synergistic effect of cell differential agent-Ⅱ and arsenic trioxide on induction of cell cycle arrest and apoptosis in hepatoma cells

    Institute of Scientific and Technical Information of China (English)

    Jian-Wei Liu; Yi Tang; Yan Shen; Xue-Yun Zhong

    2003-01-01

    AIM: To illustrate the possible role of cell differential agent-Ⅱ (CDA-Ⅱ) in the apoptosis of hepatoma cells induced byarsenic trioxide (As2O3).METHODS: Hepatoma cell lines BEL-7402 and HepG2 weretreated with As2O3 together with CDA-Ⅱ. Cell survivingfraction was determined by MTT assay; morphologicalchanges were observed by immunofluorescence staining ofHoechst 33 258; and cell cycle and the apoptosis index weredetermined by flow cytometry (FCM).RESULTS: Cytotoxity of CDA-Ⅱ was low. Nevertheless, CDA-Ⅱ could strongly potentiate arsenic trioxide-inducedapoptosis. At 1.0 g/L CDA-Ⅱ, IC50 of As2O3 in hepatoma celllines was reduced from 5.0 μmol/L to 1.0 μmol/L (P<0.01).The potentiation of apoptosis was dependent on the dosageof CDA-Ⅱ. FCM indicated that in hepatoma, cell growth wasinhibited by CDA-Ⅱ at lower concentrations (<2.0 g/L)primarily by arresting at S and G2 phase, and at higherconcentrations (>2.0 g/L) apoptotic cell and cell cyclearresting at G1 phaseincreased proportionally. Thecombination of two drugs led to much higher apoptotic rates,as compared with the either drug used alone.CONCLUSION: CDA-Ⅱ can strongly potentiate As2O3-induced apoptosis in hepatoma cells, and two drugs canproduce a significant synergic effect.

  11. Cell cycle arrest and mechanism of apoptosis induction in H400 oral cancer cells in response to Damnacanthal and Nordamnacanthal isolated from Morinda citrifolia.

    Science.gov (United States)

    Shaghayegh, Gohar; Alabsi, Aied M; Ali-Saeed, Rola; Ali, Abdul Manaf; Vincent-Chong, Vui King; Zain, Rosnah Binti

    2016-10-01

    Oral cancer is the eleventh most prevalent cancer worldwide. The most prevalent oral cancer is oral squamous cell carcinoma (OSCC). Damnacanthal (DAM) and nordamnacanthal (NDAM), the anthraquinone compounds, are isolated from the root of Morinda citrifolia L. (Noni), which has been used for the treatment of several chronic diseases including cancer. The objectives of this study were to evaluate the cytotoxicity, cell death mode, cell cycle, and the molecular mechanism of apoptosis induced by DAM and NDAM on OSCC. The cytotoxic effects of these compounds against OSCC cell lines were determined by MTT assay. The cell death mode was analysed by DNA laddering and FITC-annexin V/PI flow cytometric assays. In addition, the mechanism of apoptosis induced by DAM and NDAM was detected using mitochondrial membrane potential, Cytochrome c, and caspases assays. Finally, the effect of DAM and NDAM on cell cycle phase distribution of OSCC cells was detected by flow cytometry. In the present study, DAM and NDAM showed cytotoxicity towards OSCC cell lines and the maximum growth inhibition for both compounds was observed in H400 cells with IC50 value of 1.9 and 6.8 μg/ml, respectively, after 72 h treatment. The results also demonstrated the inhibition of H400 OSCC cells proliferation, internucleosomal cleavage of DNA, activation of intrinsic apoptosis pathway, and cell cycle arrest caused by DAM and NDAM. Therefore, these findings suggest that DAM and NDAM can be potentially used as antitumor agents for oral cancer therapy.

  12. Gomisin A enhances tumor necrosis factor-α-induced G1 cell cycle arrest via signal transducer and activator of transcription 1-mediated phosphorylation of retinoblastoma protein.

    Science.gov (United States)

    Waiwut, Pornthip; Shin, Myoung-Sook; Yokoyama, Satoru; Saiki, Ikuo; Sakurai, Hiroaki

    2012-01-01

    Gomisin A, a dibenzocyclooctadiene lignan isolated from the fruit of Schisandra chinensis, has been reported as an anti-cancer substance. In this study, we investigated the effects of gomisin A on cancer cell proliferation and cell cycle arrest in HeLa cells. Gomisin A significantly inhibited cell proliferation in a dose-dependent manner after 72 h treatment, especially in the presence of tumor necrosis factor-α (TNF-α), due to cell cycle arrest in the G1 phase with the downregulation of cyclin D1 expression and Retinoblastoma (RB) phosphorylation. In addition, gomisin A in combination with TNF-α strongly suppressed the expression of signal transducer and activator of transcription 1 (STAT1). Inhibition of STAT1 pathways by a small-interfering RNA against STAT1 and AG490 Janus kinase (JAK) kinase inhibitor AG490 reduced the cyclin D1 expression and RB phosphorylation, indicating that JAK-mediated STAT1 activation is involved in gomisin A-induced G1 cell cycle arrest.

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

    Directory of Open Access Journals (Sweden)

    Junko Mori

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

  14. American cranberry (Vaccinium macrocarpon) extract affects human prostate cancer cell growth via cell cycle arrest by modulating expression of cell cycle regulators.

    Science.gov (United States)

    Déziel, Bob; MacPhee, James; Patel, Kunal; Catalli, Adriana; Kulka, Marianna; Neto, Catherine; Gottschall-Pass, Katherine; Hurta, Robert

    2012-05-01

    Prostate cancer is one of the most common cancers in the world, and its prevalence is expected to increase appreciably in the coming decades. As such, more research is necessary to understand the etiology, progression and possible preventative measures to delay or to stop the development of this disease. Recently, there has been interest in examining the effects of whole extracts from commonly harvested crops on the behaviour and progression of cancer. Here, we describe the effects of whole cranberry extract (WCE) on the behaviour of DU145 human prostate cancer cells in vitro. Following treatment of DU145 human prostate cancer cells with 10, 25 and 50 μg ml⁻¹ of WCE, respectively for 6 h, WCE significantly decreased the cellular viability of DU145 cells. WCE also decreased the proportion of cells in the G2-M phase of the cell cycle and increased the proportion of cells in the G1 phase of the cell cycle following treatment of cells with 25 and 50 μg ml⁻¹ treatment of WCE for 6 h. These alterations in cell cycle were associated with changes in cell cycle regulatory proteins and other cell cycle associated proteins. WCE decreased the expression of CDK4, cyclin A, cyclin B1, cyclin D1 and cyclin E, and increased the expression of p27. Changes in p16(INK4a) and pRBp107 protein expression levels also were evident, however, the changes noted in p16(INK4a) and pRBp107 protein expression levels were not statistically significant. These findings demonstrate that phytochemical extracts from the American cranberry (Vaccinium macrocarpon) can affect the behaviour of human prostate cancer cells in vitro and further support the potential health benefits associated with cranberries.

  15. Design, synthesis, DNA-binding affinity, cytotoxicity, apoptosis, and cell cycle arrest of Ru(II) polypyridyl complexes.

    Science.gov (United States)

    Venkat Reddy, Putta; Reddy, Mallepally Rajender; Avudoddi, Srishailam; Praveen Kumar, Yata; Nagamani, Chintakuntla; Deepika, Nancherla; Nagasuryaprasad, K; Singh, Surya Satyanarayana; Satyanarayana, Sirasani

    2015-09-15

    A novel polypyridyl ligand CNPFIP (CNPFIP=2-(5(4-chloro-2-nitrophenyl)furan-2-yl)-1H-imidazo[4,5f][1,10]phenanthroline) and its mononuclear Ru(II) polypyridyl complexes of [Ru(phen)2CNPFIP](2+)(1) (phen=1,10-phenanthroline), [Ru(bpy)2CNPFIP](2+)(2) (bpy=2,2'-bipyridine), and [Ru(dmb)2CNPFIP](2+)(3) (dmb=4,4'-dimethyl-2,2'-bipyridine) have been synthesized successfully and characterized thoroughly by elemental analysis, UV/Vis, IR, NMR, and ESI-MS. The interaction of the Ru(II) complexes with calf thymus DNA (CT-DNA) was investigated by absorption titration, fluorescence, viscosity measurements. The experimental results suggest that three complexes bind to CT-DNA through an intercalative mode and the DNA-binding affinity of complex 1 is greater than that of complexes 2 and 3. The photocleavage of plasmid pBR322 DNA by ruthenium complexes 1, 2, and 3 was investigated. We have also tested three complexes for their antimicrobial activity against Escherichia coli (Gram-negative) and Staphylococcus aureus (Gram-positive) bacteria. The in vitro cytotoxicity of these complexes was evaluated by MTT assay, and complex 1 shows higher cytotoxicity than 2 and 3 on HeLa cells. The induced apoptosis and cell cycle arrest of HeLa cells were investigated by flow cytometry for 24h. The molecular docking of ruthenium complexes 1, 2, and 3 with the active site pocket residues of human DNA TOP1 was performed using LibDock.

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

    Science.gov (United States)

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

    2014-09-01

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

  17. Metformin inhibits salivary adenocarcinoma growth through cell cycle arrest and apoptosis

    OpenAIRE

    2015-01-01

    The inhibitory effects of metformin have been observed in many types of cancer. However, its effect on human salivary gland carcinoma is unknown. The effect of metformin alone or in combination with pp242 (an mTOR inhibitor) on salivary adenocarcinoma cells growth were determined in vitro and in vivo. We found that metformin suppressed HSY cell growth in vitro in a time and dose dependent manner associated with a reduced expression of MYC onco-protein, and the same inhibitory effect of metfor...

  18. Proliferation inhibition, cell cycle arrest and apoptosis induced in HL-60 cells by a natural diterpene ester from Daphne mucronata

    Science.gov (United States)

    Nouri, K.; Yazdanparast, R.

    2011-01-01

    Background and the purpose of the study Gnidilatimonoein (Gn), a new diterpene ester from Daphne mucronata, possesses strong anti-metastasis and anti-tumor activities. In this study, its apoptosis and differentiation capabilities were evaluated by using the leukemia HL-60 cell line. Material and methods Cell prolifaration inhibition was estimated by MTT assay. The occurrence of apoptosis was evaluated by EtBr/AO double staining technique, cell cycle analyses and detection of apoptotic cells by Annexin V-FITC and propodium iodide (PI). Differentiation of the cells was determined by NBT reduction assay and the expression of specific cell surface markers such as CD14 and CD11b, were analyzed by flow cytometry. Results The drug decreased the growth of the cells dose- and time-dependently and the IC50 was found to be 1.3 µM. Our data suggested that Gn induced both monocytic differentiation and apoptosis among HL-60 cells. In addition, cell cycle analyses showed an increase in G1 phase population by 24 hrs, which was gradually replaced by Sub-G1 cell population (apoptotic cells) by 72 hrs. Conclusion Based on these data, the Gn-treated HL-60 cells displayed differentiation-dependent apoptosis. Thus, Gn might be a good candidate for differentiation therapy of leukemia, pending full biological evaluation of the compound among the wide array of leukemia cells. PMID:22615651

  19. The induction of microRNA-16 in colon cancer cells by protein arginine deiminase inhibition causes a p53-dependent cell cycle arrest.

    Directory of Open Access Journals (Sweden)

    Xiangli Cui

    Full Text Available Protein Arginine Deiminases (PADs catalyze the post-translational conversion of peptidyl-Arginine to peptidyl-Citrulline in a calcium-dependent, irreversible reaction. Evidence is emerging that PADs play a role in carcinogenesis. To determine the cancer-associated functional implications of PADs, we designed a small molecule PAD inhibitor (called Chor-amidine or Cl-amidine, and tested the impact of this drug on the cell cycle. Data derived from experiments in colon cancer cells indicate that Cl-amidine causes a G1 arrest, and that this was p53-dependent. In a separate set of experiments, we found that Cl-amidine caused a significant increase in microRNA-16 (miRNA-16, and that this increase was also p53-dependent. Because miRNA-16 is a putative tumor suppressor miRNA, and others have found that miRNA-16 suppresses proliferation, we hypothesized that the p53-dependent G1 arrest associated with PAD inhibition was, in turn, dependent on miRNA-16 expression. Results are consistent with this hypothesis. As well, we found the G1 arrest is at least in part due to the ability of Cl-amidine-mediated expression of miRNA-16 to suppress its' G1-associated targets: cyclins D1, D2, D3, E1, and cdk6. Our study sheds light into the mechanisms by which PAD inhibition can protect against or treat colon cancer.

  20. The Mechanism of Tetinoblastoma Protein-Mediated Terminal Cell Cycle Arrest

    Science.gov (United States)

    2005-09-01

    SantaCruz Biotech) or cyclin Dl (AB-3, Neomarker) antibody, c-Fos, c-Jun, Fra-2 and MyoD antibody ( SantaCruz Biotech Inc., USA). Figure 3. The temporal...promoter. Figure 12. Chormatin Immunoprecipitation (ChIP) assay for differentiated genuine mouse myoblast cells using MyoD antibody ( SantaCruz Biotech, SC

  1. Cytotoxic Activity and G1 Cell Cycle Arrest of a Dienynone from Echinacea pallida

    DEFF Research Database (Denmark)

    Chicca, Andrea; Adinolfi, Barbara; Pellati, Federica;

    2009-01-01

    In the present study, a further investigation of the cytotoxic activity of an acetylenic constituent of ECHINACEA PALLIDA roots, namely, pentadeca-(8 Z,13 Z)-dien-11-yn-2-one, was performed, revealing a concentration-dependent cytotoxicity on several human cancer cell lines, including leukemia...

  2. Combination of lentivirus-mediated silencing of PPM1D and temozolomide chemotherapy eradicates malignant glioma through cell apoptosis and cell cycle arrest

    Science.gov (United States)

    Wang, Peng; Ye, Jing-An; Hou, Chong-Xian; Zhou, Dong; Zhan, Sheng-Quan

    2016-01-01

    Temozolomide (TMZ) is approved for use as first-line treatment for glioblastoma multiforme (GBM). However, GBM shows chemoresistance shortly after the initiation of treatment. In order to detect whether silencing of human protein phosphatase 1D magnesium dependent (PPM1D) gene could increase the effects of TMZ in glioma cells, glioma cells U87-MG were infected with lentiviral shRNA vector targeting PPM1D silencing. After PPM1D silencing was established, cells were treated with TMZ. The multiple functions of human glioma cells after PPM1D silencing and TMZ chemotherapy were detected by flow cytometry and MTT assay. Significantly differentially expressed genes were distinguished by microarray-based gene expression profiling and analyzed by gene pathway enrichment analysis and ontology assessment. Western blotting was used to establish the protein expression of the core genes. PPM1D gene silencing improves TMZ induced cell proliferation and induces cell apoptosis and cell cycle arrest. When PPM1D gene silencing combined with TMZ was performed in glioma cells, 367 genes were upregulated and 444 genes were downregulated compared with negative control. The most significant differential expression pathway was pathway in cancer and IGFR1R, PIK3R1, MAPK8 and EP300 are core genes in the network. Western blotting showed that MAPK8 and PIK3R1 protein expression levels were upregulated and RB1 protein expression was decreased. It was consistent with that detected in gene expression profiling. In conclusion, PPM1D gene silencing combined with TMZ eradicates glioma cells through cell apoptosis and cell cycle arrest. PIK3R1/AKT pathway plays a role in the multiple functions of glioma cells after PPM1D silencing and TMZ chemotherapy. PMID:27633132

  3. A molecular understanding of D-homoestrone-induced G2/M cell cycle arrest in HeLa human cervical carcinoma cells.

    Science.gov (United States)

    Minorics, Renáta; Bózsity, Noémi; Molnár, Judit; Wölfling, János; Mernyák, Erzsébet; Schneider, Gyula; Ocsovszki, Imre; Zupkó, István

    2015-10-01

    2-Methoxyestradiol (ME), one of the most widely investigated A-ring-modified metabolites of estrone, exerts significant anticancer activity on numerous cancer cell lines. Its pharmacological actions, including cell cycle arrest, microtubule disruption and pro-apoptotic activity, have already been described in detail. The currently tested D-ring-modified analogue of estrone, D-homoestrone, selectively inhibits cervical cancer cell proliferation and induces a G2/M phase cell cycle blockade, resulting in the development of apoptosis. The question arose of whether the difference in the chemical structures of these analogues can influence the mechanism of anticancer action. The aim of the present study was therefore to elucidate the molecular contributors of intracellular processes induced by D-homoestrone in HeLa cells. Apoptosis triggered by D-homoestrone develops through activation of the intrinsic pathway, as demonstrated by determination of the activities of caspase-8 and -9. It was revealed that D-homoestrone-treated HeLa cells are not able to enter mitosis because the cyclin-dependent kinase 1-cyclin B complex loses its activity, resulting in the decreased inactivation of stathmin and a concomitant disturbance of microtubule formation. However, unlike 2-ME, D-homoestrone does not exert a direct effect on tubulin polymerization. These results led to the conclusion that the D-homoestrone-triggered intracellular processes resulting in a cell cycle arrest and apoptosis in HeLa cells differ from those in the case of 2-ME. This may be regarded as an alternative mechanism of action among steroidal anticancer compounds.

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

    Directory of Open Access Journals (Sweden)

    Yohko Fujimoto

    2014-06-01

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

  5. Evolutionarily conserved pressure for the existence of distinct G2/M cell cycle arrest and A3H inactivation functions in HIV-1 Vif.

    Science.gov (United States)

    Zhao, Ke; Du, Juan; Rui, Yajuan; Zheng, Wenwen; Kang, Jian; Hou, Jingwei; Wang, Kang; Zhang, Wenyan; Simon, Viviana A; Yu, Xiao-Fang

    2015-01-01

    HIV-1 Vif assembles the Cul5-EloB/C E3 ubiquitin ligase to induce proteasomal degradation of the cellular antiviral APOBEC3 proteins. Detailed structural studies have confirmed critical functional domains in Vif that we have previously identified as important for the interaction of EloB/C, Cul5, and CBFβ. However, the mechanism by which Vif recognizes substrates remains poorly understood. Specific regions of Vif have been identified as being responsible for binding and depleting APOBEC3G and APOBEC3F. Interestingly, we have now identified distinct yet overlapping domains that are required for HIV-1 Vif-mediated G2/M-phase cell cycle arrest and APOBEC3H degradation, but not for the inactivation of APOBEC3G or APOBEC3F. Surprisingly, Vif molecules from primary HIV-1 variants that caused G2/M arrest were unable to inactivate APOBEC3H; on the other hand, HIV-1 Vif variants that could inactivate APOBEC3H were unable to induce G2/M arrest. All of these Vif variants still maintained the ability to inactivate APOBEC3G/F. Thus, primary HIV-1 variants have evolved to possess distinct functional activities that allow them to suppress APOBEC3H or cause G2 cell cycle arrest, using mutually exclusive interface domains. APOBEC3H depletion and G2 arrest are apparently evolutionary selected features that cannot co-exist on a single Vif molecule. The existence and persistence of both types of HIV-1 Vif variant suggests the importance of APOBEC3H suppression and cell cycle regulation for HIV-1's survival in vivo.

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

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Seung-il; Dadakhujaev, Shorafidinkhuja; Maeng, Yong-Sun; Ahn, So-yeon; Kim, Tae-im [Department of Ophthalmology, Severance Hospital, Yonsei University College of Medicine, Seoul (Korea, Republic of); Corneal Dystrophy Research Institute, Yonsei University College of Medicine, Seoul (Korea, Republic of); Kim, Eung Kweon, E-mail: eungkkim@yuhs.ac [Department of Ophthalmology, Severance Hospital, Yonsei University College of Medicine, Seoul (Korea, Republic of); Corneal Dystrophy Research Institute, Yonsei University College of Medicine, Seoul (Korea, Republic of); BK21 Plus Project for Medical Science and Severance Biomedical Science Institute, Yonsei University College of Medicine, Seoul (Korea, Republic of)

    2015-01-02

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

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

    Science.gov (United States)

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

    2015-01-01

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

  8. Cell cycle arrest promotes trans-hammerhead ribozyme action in yeast.

    Science.gov (United States)

    Ferbeyre, G; Bratty, J; Chen, H; Cedergren, R

    1996-08-09

    A hammerhead ribozyme designed to cleave the yeast ADE1 mRNA has been expressed in yeast under the control of a galactose-inducible promoter. RNA prepared from the galactose-induced yeast cultures possesses an activity that cleaves ADE1 mRNA in vitro. However, in spite of high expression levels of the ribozyme, no cleavage activity could be demonstrated in vivo. On the other hand, when the yeast cells expressing hammerhead RNA were treated with the alpha-factor mating pheromone, the level of ADE1 mRNA was reduced by 50%. Similar reductions were observed when this strain was cultured in the presence of lithium acetate or in nitrogen-free medium. Moreover, control experiments in which disabled hammerhead genes were expressed showed no such reductions. Extension of the length of the flanking recognition arms of the ribozyme from a total of 10 to 16 or 24 nucleotides diminished the inhibitory effect of the ribozyme. These data suggest that ribozymes are able to cleave a trans-RNA target in yeast.

  9. Deficiency of G1 regulators P53, P21Cip1 and/or pRb decreases hepatocyte sensitivity to TGFβ cell cycle arrest

    Directory of Open Access Journals (Sweden)

    Harrison David J

    2007-11-01

    Full Text Available Abstract Background TGFβ is critical to control hepatocyte proliferation by inducing G1-growth arrest through multiple pathways leading to inhibition of E2F transcription activity. The retinoblastoma protein pRb is a key controller of E2F activity and G1/S transition which can be inhibited in viral hepatitis. It is not known whether the impairment of pRb would alter the growth inhibitory potential of TGFβ in disease. We asked how Rb-deficiency would affect responses to TGFβ-induced cell cycle arrest. Results Primary hepatocytes isolated from Rb-floxed mice were infected with an adenovirus expressing CRE-recombinase to delete the Rb gene. In control cells treatment with TGFβ prevented cells to enter S phase via decreased cMYC activity, activation of P16INK4A and P21Cip and reduction of E2F activity. In Rb-null hepatocytes, cMYC activity decreased slightly but P16INK4A was not activated and the great majority of cells continued cycling. Rb is therefore central to TGFβ-induced cell cycle arrest in hepatocytes. However some Rb-null hepatocytes remained sensitive to TGFβ-induced cell cycle arrest. As these hepatocytes expressed very high levels of P21Cip1 and P53 we investigated whether these proteins regulate pRb-independent signaling to cell cycle arrest by evaluating the consequences of disruption of p53 and p21Cip1. Hepatocytes deficient in p53 or p21Cip1 showed diminished growth inhibition by TGFβ. Double deficiency had a similar impact showing that in cells containing functional pRb; P21Cip and P53 work through the same pathway to regulate G1/S in response to TGFβ. In Rb-deficient cells however, p53 but not p21Cip deficiency had an additive effect highlighting a pRb-independent-P53-dependent effector pathway of inhibition of E2F activity. Conclusion The present results show that otherwise genetically normal hepatocytes with disabled p53, p21Cip1 or Rb genes respond less well to the antiproliferative effects of TGFβ. As the function of

  10. Induction of cell cycle arrest at G1 and S phases and cAMP-dependent differentiation in C6 glioma by low concentration of cycloheximide

    Directory of Open Access Journals (Sweden)

    Zhang Samuel S

    2010-12-01

    Full Text Available Abstract Background Differentiation therapy has been shown effective in treatment of several types of cancer cells and may prove to be effective in treatment of glioblastoma multiforme, the most common and most aggressive primary brain tumor. Although extensively used as a reagent to inhibit protein synthesis in mammalian cells, whether cycloheximide treatment leads to glioma cell differentiation has not been reported. Methods C6 glioma cell was treated with or without cycloheximide at low concentrations (0.5-1 μg/ml for 1, 2 and 3 days. Cell proliferation rate was assessed by direct cell counting and colony formation assays. Apoptosis was assessed by Hoechst 33258 staining and FACS analysis. Changes in several cell cycle regulators such as Cyclins D1 and E, PCNA and Ki67, and several apoptosis-related regulators such as p53, p-JNK, p-AKT, and PARP were determined by Western blot analysis. C6 glioma differentiation was determined by morphological characterization, immunostaining and Western blot analysis on upregulation of GFAP and o p-STAT3 expression, and upregulation of intracellular cAMP. Results Treatment of C6 cell with low concentration of cycloheximide inhibited cell proliferation and depleted cells at both G2 and M phases, suggesting blockade at G1 and S phases. While no cell death was observed, cells underwent profound morphological transformation that indicated cell differentiation. Western blotting and immunostaining analyses further indicated that changes in expression of several cell cycle regulators and the differentiation marker GFAP were accompanied with cycloheximide-induced cell cycle arrest and cell differentiation. Increase in intracellular cAMP, a known promoter for C6 cell differentiation, was found to be elevated and required for cycloheximide-promoted C6 cell differentiation. Conclusion Our results suggest that partial inhibition of protein synthesis in C6 glioma by low concentration of cycloheximide induces cell cycle

  11. The inhibition of PI3K and NFκB promoted curcumin-induced cell cycle arrest at G2/M via altering polyamine metabolism in Bcl-2 overexpressing MCF-7 breast cancer cells.

    Science.gov (United States)

    Berrak, Özge; Akkoç, Yunus; Arısan, Elif Damla; Çoker-Gürkan, Ajda; Obakan-Yerlikaya, Pınar; Palavan-Ünsal, Narçin

    2016-02-01

    Bcl-2 protein has been contributed with number of genes which are involved in oncogenesis. Among the many targets of Bcl-2, NFκB have potential role in induction of cell cycle arrest. Curcumin has potential therapeutic effects against breast cancer through multiple signaling pathways. In this study, we investigated the role of curcumin in induction of cell cycle arrest via regulating of NFκB and polyamine biosynthesis in wt and Bcl-2+ MCF-7 cells. To examine the effect of curcumin on cell cycle regulatory proteins, PI3K/Akt, NFκB pathways and polyamine catabolism, we performed immunoblotting assay. In addition, cell cycle analysis was performed by flow cytometry. The results indicated that curcumin induced cell cycle arrest at G2/M phase by downregulation of cyclin B1 and Cdc2 and inhibited colony formation in MCF-7wt cells. However, Bcl-2 overexpression prevented the inhibition of cell cycle associated proteins after curcumin treatment. The combination of LY294002, PI3K inhibitor, and curcumin induced cell cycle arrest by decreasing CDK4, CDK2 and cyclin E2 in Bcl-2+ MCF-7 cells. Moreover, LY294002 further inhibited the phosphorylation of Akt in Bcl-2+ MCF-7 cells. Curcumin could suppress the nuclear transport of NFκB through decreasing the interaction of P-IκB-NFκB. The combination of wedelolactone, NFκB inhibitor, and curcumin acted different on SSAT expression in wt MCF-7 and Bcl-2+ MCF-7 cells. NFκB inhibition increased the SSAT after curcumin treatment in Bcl-2 overexpressed MCF-7 cells. Inhibition of NFκB activity as well as suppression of ROS generation with NAC resulted in the partial relief of cells from G2/M checkpoint after curcumin treatment in wt MCF-7 cells. In conclusion, the potential role of curcumin in induction of cell cycle arrest is related with NFκB-regulated polyamine biosynthesis.

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

    Directory of Open Access Journals (Sweden)

    Nan Hua

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

  13. The long non-coding RNA HOTAIR promotes the proliferation of serous ovarian cancer cells through the regulation of cell cycle arrest and apoptosis

    Energy Technology Data Exchange (ETDEWEB)

    Qiu, Jun-jun [Department of Gynecology, Obstetrics and Gynecology Hospital, Fudan University, 419 Fangxie Road, Shanghai 200011 (China); Department of Obstetrics and Gynecology of Shanghai Medical College, Fudan University, 138 Yixueyuan Road, Shanghai 200032 (China); Shanghai Key Laboratory of Female Reproductive Endocrine-Related Diseases, 413 Zhaozhou Road, Shanghai 200011 (China); Wang, Yan [Cancer Institute, Fudan University Shanghai Cancer Center, 270 Dong' an Road, Shanghai 200032 (China); Department of Oncology, Shanghai Medical College, Fudan University, 130 Dong' an Road, Shanghai 200032 (China); Ding, Jing-xin; Jin, Hong-yan [Department of Gynecology, Obstetrics and Gynecology Hospital, Fudan University, 419 Fangxie Road, Shanghai 200011 (China); Department of Obstetrics and Gynecology of Shanghai Medical College, Fudan University, 138 Yixueyuan Road, Shanghai 200032 (China); Shanghai Key Laboratory of Female Reproductive Endocrine-Related Diseases, 413 Zhaozhou Road, Shanghai 200011 (China); Yang, Gong, E-mail: yanggong@fudan.edu.cn [Cancer Institute, Fudan University Shanghai Cancer Center, 270 Dong' an Road, Shanghai 200032 (China); Department of Oncology, Shanghai Medical College, Fudan University, 130 Dong' an Road, Shanghai 200032 (China); Hua, Ke-qin, E-mail: huakeqin@126.com [Department of Gynecology, Obstetrics and Gynecology Hospital, Fudan University, 419 Fangxie Road, Shanghai 200011 (China); Department of Obstetrics and Gynecology of Shanghai Medical College, Fudan University, 138 Yixueyuan Road, Shanghai 200032 (China); Shanghai Key Laboratory of Female Reproductive Endocrine-Related Diseases, 413 Zhaozhou Road, Shanghai 200011 (China)

    2015-05-01

    HOX transcript antisense RNA (HOTAIR) is a well-known long non-coding RNA (lncRNA) whose dysregulation correlates with poor prognosis and malignant progression in many forms of cancer. Here, we investigate the expression pattern, clinical significance, and biological function of HOTAIR in serous ovarian cancer (SOC). Clinically, we found that HOTAIR levels were overexpressed in SOC tissues compared with normal controls and that HOTAIR overexpression was correlated with an advanced FIGO stage and a high histological grade. Multivariate analysis revealed that HOTAIR is an independent prognostic factor for predicting overall survival in SOC patients. We demonstrated that HOTAIR silencing inhibited A2780 and OVCA429 SOC cell proliferation in vitro and that the anti-proliferative effects of HOTAIR silencing also occurred in vivo. Further investigation into the mechanisms responsible for the growth inhibitory effects by HOTAIR silencing revealed that its knockdown resulted in the induction of cell cycle arrest and apoptosis through certain cell cycle-related and apoptosis-related proteins. Together, these results highlight a critical role of HOTAIR in SOC cell proliferation and contribute to a better understanding of the importance of dysregulated lncRNAs in SOC progression. - Highlights: • HOTAIR overexpression correlates with an aggressive tumour phenotype and a poor prognosis in SOC. • HOTAIR promotes SOC cell proliferation both in vitro and in vivo. • The proliferative role of HOTAIR is associated with regulation of the cell cycle and apoptosis.

  14. Alpinia pricei Rhizome Extracts Induce Cell Cycle Arrest in Human Squamous Carcinoma KB Cells and Suppress Tumor Growth in Nude Mice

    Directory of Open Access Journals (Sweden)

    You-Cheng Hseu

    2011-01-01

    Full Text Available Alpinia pricei has been shown to induce apoptosis in human squamous carcinoma (KB cells. In this study, we report the effectiveness of the ethanol (70% extracts of A. pricei rhizome (AP extracts in terms of tumor regression as determined using both in vitro cell culture and in vivo athymic nude mice models of KB cells. We found that the AP extract (25–200 μg/mL treatment decreased the proliferation of KB cells by arresting progression through the G2/M phase of the cell cycle. This cell cycle blockade was associated with reductions in cyclin A and B1, Cdc2, and Cdc25C, and increased p21/WAF1, Wee1, p53 and phospho-p53 (p-p53 in a dose- and time-dependent manner. Moreover, we found that AP extract treatment decreased metalloproteinase-9 (MMP-9 and urokinase plasminogen activator (u-PA expression, while expression of their endogenous inhibitors, tissue inhibitor of MMP-1 (TIMP-1 and plasminogen activator inhibitor-1 (PAI-1, were increased in KB cells. Furthermore, AP extract treatment effectively delayed tumor incidence in nude mice inoculated with KB cells and reduced the tumor burden. AP extract treatment also induced apoptotic DNA fragmentation, as detected by in situ TUNEL staining. Thus, A. pricei may possess antitumor activity in human squamous carcinoma (KB cells.

  15. Induction of cell cycle arrest via the p21, p27–cyclin E,A/Cdk2 pathway in SMMC-7721 hepatoma cells by clioquinol

    Directory of Open Access Journals (Sweden)

    Huang Zhiwei

    2015-12-01

    Full Text Available Clioquinol has been shown to have anticancer activity in several carcinoma cells. In this study, we preliminarily examined the effect of clioquinol in human SMMC-7721 hepatoma and QSG-7701 normal hepatic cells. Our results indicated that clioquinol did not significantly affect survival of QSG-7701 cells, whereas it reduced cell viability in a concentration- and time-dependent manner in SMMC-7721 cells. Clioquinol did not trigger autophagy and apoptosis, while it induced cell cycle arrest in the S-phase in SMMC- 7721 cells. Additionally, down-regulation of cyclin D1, A2, E1, Cdk2 and up-regulation of p21, p27 were detected after the treatment with clioquinol. The results demonstrated for the first time that clioquinol suppressed cell cycle progression in the S-phase in SMMC-7721 cells via the p21, p27-cyclin E,A/Cdk2 pathway. This suggests that clioquinol may have a therapeutic potential as an anticancer drug for certain malignances.

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

    Directory of Open Access Journals (Sweden)

    Rahman HS

    2014-01-01

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

  17. KU004 induces G1 cell cycle arrest in human breast cancer SKBR-3 cells by modulating PI3K/Akt pathway.

    Science.gov (United States)

    Fu, Jing; Tian, Chongchong; Xing, Mengtao; Wang, Xinzhi; Guo, Hongli; Sun, Lixin; Sun, Lan; Jiang, Zhenzhou; Zhang, Luyong

    2014-06-01

    KU004 is a newly synthesized compound which has been demonstrated possessing potent anti-cancer activities through targeting the highly-expressed protein HER2 on the surface of the cells. In this study, we investigated the potential roles of KU004 in the induced-cell cycle arrest in human breast cancer SK-BR-3 cells. KU004 could not only inhibit the proliferation of SK-BR-3 in a concentration-dependent manner but also induce G1 phase arrest in SK-BR-3 cells. The western blot results showed KU004 decreased the expression of cyclin D, CDK-4, p-Rb708/780, and up-regulated the p21. In order to verify whether KU004 takes the anti-tumor effect thought the regulation of PI3K/Akt pathway, we used western blot to detect the expression of protein Akt, Her2, p-Akt and p-Her2. Our results shown that after KU004 treatment, the amount of p-Akt and p-Her2 decreased but the total amount of Akt and Her2 remained unchanged. In conclusion, these results provide a framework for further exploration of KU004 as a novel chemotherapeutic for human breast tumors by modulating PI3K/Akt pathway.

  18. Ethyl acetate extract of Peperomia tetraphylla induces cytotoxicity, cell cycle arrest, and apoptosis in lymphoma U937 cells.

    Science.gov (United States)

    Yu, Dayong; Yang, Xiuxiu; Lu, Xuan; Shi, Liying; Feng, Baomin

    2016-12-01

    The current study evaluated the cytotoxicity and the mechanism of apoptotic induction by Peperomia tetraphylla in U937 lymphoma cells. The results showed that P. tetraphylla ethyl acetate extract (EAEPT) inhibited the cell growth in U937 cells by MTT assay. After the U937 cells were treated with EAEPT, the cells exhibited marked morphological features of apoptosis (Hoechst 33342 staining) and the number of apoptotic cell (Annexin V-FITC/PI staining) increased. The treatment of EAEPT could induce loss of mitochondrial membrane potential (MMP) and increase the ROS level. Moreover, EAEPT treatment resulted in the accumulation of cells at S phase. We found that EAEPT could induce the cleavage of the caspase 3, caspase 8, caspase 9 and Bid. And the treatment of EAEPT could increase expression of Bax and down-regulate the expression of CCNB1, CCND1 and CDK1. The sub-fraction of EAEPT, namely EASub1 demonstrated the highest cytotoxicity activity on U937 cells. It was confirmed that EAEPT could inhibit the growth of U937 cells by blocking the cell cycle and prompted apoptosis via the ROS-medicated mitochondria pathway in vitro.

  19. Effects of 5,6-Dihydroxy-2,4-Dimethoxy-9,10-Dihydrophenanthrene on G2/M Cell Cycle Arrest and Apoptosis in Human Lung Carcinoma Cells.

    Science.gov (United States)

    Duangprompo, Wipada; Aree, Kalaya; Itharat, Arunporn; Hansakul, Pintusorn

    2016-01-01

    5,6-dihydroxy-2,4-dimethoxy-9,10-dihydrophenanthrene (HMP) is an active compound isolated from the rhizome extracts of Dioscorea membranacea Pierre, a Thai medicinal plant. This study aimed to investigate the growth-inhibitory and apoptosis-inducing effects of HMP in human lung cancer A549 cells. The antiproliferative and cytotoxic effects of HMP were analyzed by a Sulforhodamine B assay. Cell division, cell cycle distribution and membrane asymmetry changes were each performed with different fluorescent dyes and then analyzed by flow cytometry. Real-time PCR and immunoblotting were used to detect cell cycle- and apoptosis-related mRNA levels and proteins, respectively. The nuclear morphology of the cells stained with DAPI and DNA fragmentation were detected by fluorescence microscopy and gel electrophoresis, respectively. The results showed that HMP exerted strong antiproliferative and cytotoxic activities in A549 cells with the highest selectivity index. It halted the cell cycle in [Formula: see text]/M phase via down-regulation of the expression levels of regulatory proteins Cdc25C, Cdk1 and cyclinB1. In addition, HMP induced early apoptotic cells with externalized phosphatidylserine and subsequent apoptotic cells in sub-[Formula: see text] phase. HMP increased caspase-3 activity and levels of the cleaved (active) form of caspase-3 whose actions were supported by the cleavage of its target PARP, nuclear condensation and DNA apoptotic ladder. Moreover, HMP significantly increased the mRNA and protein levels of proapoptotic Bax as well as promoted subsequent caspase-9 activation and BID cleavage, indicating HMP-induced apoptosis via both intrinsic and extrinsic pathways. These data support, for the first time, the potential role of HMP as a cell-cycle arrest and apoptosis-inducing agent for lung cancer treatment.

  20. The depletion of Interleukin-8 causes cell cycle arrest and increases the efficacy of docetaxel in breast cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Shao, Nan [Breast Disease Center, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou (China); Chen, Liu-Hua [Department of Minimally Invasive Surgery Center, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou (China); Ye, Run-Yi [Breast Disease Center, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou (China); Lin, Ying, E-mail: frostlin@hotmail.com [Breast Disease Center, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou (China); Wang, Shen-Ming, E-mail: shenmingwang@hotmail.com [Breast Disease Center, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou (China)

    2013-02-15

    Highlights: ► IL-8 depletion affects cell cycle distribution. ► Intrinsic IL-8 mediates breast cancer cell migration and invasion. ► IL-8 siRNA down regulates key factors that control survival and metastatic pathway. ► IL-8 depletion reduces integrin β3 expression. ► IL-8 depletion increases the chemosensitivity to docetaxel. -- Abstract: IL-8 is a multi-functional pro-inflammatory chemokine, which is highly expressed in cancers, such as ER-negative breast cancer. The present study demonstrates the pervasive role of IL-8 in the malignant progression of ER-negative breast cancer. IL-8 siRNA inhibited proliferation and delayed the G1 to S cell cycle progression in MDA-MB-231 and BT549 cells. IL-8 silencing resulted in the upregulation of the CDK inhibitor p27, the downregulation of cyclin D1, and the reduction of phosphorylated-Akt and NF-κB activities. IL-8 depletion also increased the chemosensitivity to docetaxel. These results indicate a role for IL-8 in promoting tumor cell survival and resistance to docetaxel and highlight the potential therapeutic significance of IL-8 depletion in ER-negative breast cancer patients.

  1. 1-(2-Hydroxy-5-methylphenyl)-3-phenyl-1,3-propanedione Induces G1 Cell Cycle Arrest and Autophagy in HeLa Cervical Cancer Cells

    Science.gov (United States)

    Tsai, Jie-Heng; Hsu, Li-Sung; Huang, Hsiu-Chen; Lin, Chih-Li; Pan, Min-Hsiung; Hong, Hui-Mei; Chen, Wei-Jen

    2016-01-01

    The natural agent, 1-(2-hydroxy-5-methylphenyl)-3-phenyl-1,3-propanedione (HMDB), has been reported to have growth inhibitory effects on several human cancer cells. However, the role of HMDB in cervical cancer remains unclear. Herein, we found that HMDB dose- and time-dependently inhibited growth of HeLa cervical cancer cells, accompanied with G1 cell cycle arrest. HMDB decreased protein expression of cyclins D1/D3/E and cyclin-dependent kinases (CDKs) 2/4/6 and reciprocally increased mRNA and protein levels of CDK inhibitors (p15, p16, p21, and p27), thereby leading to the accumulation of hypophosphorylated retinoblastoma (Rb) protein. HMDB also triggered the accumulation of acidic vesicles and formation of microtubule-associated protein-light chain 3 (LC3), followed by increased expression of LC3 and Beclin-1 and decreased expression of p62, suggesting that HMDB triggered autophagy in HeLa cells. Meanwhile, suppression of the expression of survivin and Bcl-2 implied that HMDB-induced autophagy is tightly linked to apoptosis. Exploring the action mechanism, HMDB induced autophagy via the modulation of AMP-activated protein kinase (AMPK) and mTOR signaling pathway rather than the class III phosphatidylinositol 3-kinase pathway. These results suggest that HMDB inhibits HeLa cell growth by eliciting a G1 arrest through modulation of G1 cell cycle regulators and by concomitantly inducing autophagy through the mediation of AMPK-mTOR and Akt-mTOR pathways, and may be a promising antitumor agent against cervical cancer. PMID:27527160

  2. 1-(2-Hydroxy-5-methylphenyl-3-phenyl-1,3-propanedione Induces G1 Cell Cycle Arrest and Autophagy in HeLa Cervical Cancer Cells

    Directory of Open Access Journals (Sweden)

    Jie-Heng Tsai

    2016-08-01

    Full Text Available The natural agent, 1-(2-hydroxy-5-methylphenyl-3-phenyl-1,3-propanedione (HMDB, has been reported to have growth inhibitory effects on several human cancer cells. However, the role of HMDB in cervical cancer remains unclear. Herein, we found that HMDB dose- and time-dependently inhibited growth of HeLa cervical cancer cells, accompanied with G1 cell cycle arrest. HMDB decreased protein expression of cyclins D1/D3/E and cyclin-dependent kinases (CDKs 2/4/6 and reciprocally increased mRNA and protein levels of CDK inhibitors (p15, p16, p21, and p27, thereby leading to the accumulation of hypophosphorylated retinoblastoma (Rb protein. HMDB also triggered the accumulation of acidic vesicles and formation of microtubule-associated protein-light chain 3 (LC3, followed by increased expression of LC3 and Beclin-1 and decreased expression of p62, suggesting that HMDB triggered autophagy in HeLa cells. Meanwhile, suppression of the expression of survivin and Bcl-2 implied that HMDB-induced autophagy is tightly linked to apoptosis. Exploring the action mechanism, HMDB induced autophagy via the modulation of AMP-activated protein kinase (AMPK and mTOR signaling pathway rather than the class III phosphatidylinositol 3-kinase pathway. These results suggest that HMDB inhibits HeLa cell growth by eliciting a G1 arrest through modulation of G1 cell cycle regulators and by concomitantly inducing autophagy through the mediation of AMPK-mTOR and Akt-mTOR pathways, and may be a promising antitumor agent against cervical cancer.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-02-27

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

  4. CSN5 silencing inhibits invasion and arrests cell cycle progression in human colorectal cancer SW480 and LS174T cells in vitro.

    Science.gov (United States)

    Zhong, Gang; Li, Huikai; Shan, Tao; Zhang, Nan

    2015-01-01

    CSN5 has been implicated as a candidate oncogene in human cancers by genetic linkage with activation of the poor-prognosis, wound response gene expression signature. The present study aimed to investigate the effect of silencing CSN5 on invasion and cell cycle progression of human colorectal cancer cells, and to determine the potential molecular mechanisms that are involved. The CSN5 specific small interfering RNA (shRNA) plasmid vector was constructed and then transfected into colorectal cancer cells. The expression of CSN5 mRNA and protein was detected by quantitative polymerase chain reaction and western blot analysis, respectively. Cell adhesion and invasion were analyzed using MTS and Transwell assays, respectively, and cell cycle progression was analyzed using flow cytometry. Adhesion, invasion, and cell cycle distribution were assessed following knockdown of CSN5 by RNA interference (RNAi). Furthermore, knockdown of CSN5 significantly inhibited cell adhesion and reduced the number of invasive cells, while increasing the percentage of cells in the G0/G1 phase (Pcell cycle associated proteins in cells with silenced CSN5. The expression levels of CSN5 in colorectal cancer cells transfected with siRNA were decreased, leading to a significant inhibition of colorectal cancer cell adhesion and invasion. Western blot analysis revealed that silencing of CSN5 may inhibit CD44, matrix metalloproteinase (MMP) 2 and MMP 9 protein expression, significantly promoted cell cycle-related genes P53 and P27 expression. In addition, CSN5 silencing may induce activation PI3K/AKT signal regulated cell invasion. Moreover, CSN5 silencing inhibited the secretion of TGF-β, IL-1β and IL-6 and the transcriptional activity of transcription factor NF-κB and Twist in human colorectal cancer cells. Taken together, down regulation of CSN5 may inhibit invasion and arrests cell cycle progression in colorectal cancer via PI3K/AKT/NF-κB signal pathway, which indicates that there is a

  5. Epistatic participation of REV1 and REV3 in the formation of UV-induced frameshift mutations in cell cycle-arrested yeast cells

    Energy Technology Data Exchange (ETDEWEB)

    Heidenreich, Erich [Institute of Cancer Research, Department of Medicine I, Medical University of Vienna, Borschkegasse 8a, A-1090 Vienna (Austria)]. E-mail: erich.heidenreich@meduniwien.ac.at; Eisler, Herfried [Institute of Cancer Research, Department of Medicine I, Medical University of Vienna, Borschkegasse 8a, A-1090 Vienna (Austria); Steinboeck, Ferdinand [Institute of Cancer Research, Department of Medicine I, Medical University of Vienna, Borschkegasse 8a, A-1090 Vienna (Austria)

    2006-01-29

    Mutations arising in times of cell cycle arrest may provide a selective advantage for unicellular organisms adapting to environmental changes. For multicellular organisms, however, they may pose a serious threat, in that such mutations in somatic cells contribute to carcinogenesis and ageing. The budding yeast Saccharomyces cerevisiae presents a convenient model system for studying the incidence and the mechanisms of stationary-phase mutation in a eukaryotic organism. Having studied the emergence of frameshift mutants after several days of starvation-induced cell cycle arrest, we previously reported that all (potentially error-prone) translesion synthesis (TLS) enzymes identified in S. cerevisiae did not contribute to the basal level of spontaneous stationary-phase mutations. However, we observed that an increased frequency of stationary-phase frameshift mutations, brought about by a defective nucleotide excision repair (NER) pathway or by UV irradiation, was dependent on Rev3p, the catalytic subunit of the TLS polymerase zeta (Pol {zeta}). Employing the same two conditions, we now examined the effect of deletions of the genes coding for polymerase eta (Pol {eta}) (RAD30) and Rev1p (REV1). In a NER-deficient strain background, the increased incidence of stationary-phase mutations was only moderately influenced by a lack of Pol {eta} but completely reduced to wild type level by a knockout of the REV1 gene. UV-induced stationary-phase mutations were abundant in wild type and rad30{delta} strains, but substantially reduced in a rev1{delta} as well as a rev3{delta} strain. The similarity of the rev1{delta} and the rev3{delta} phenotype and an epistatic relationship evident from experiments with a double-deficient strain suggests a participation of Rev1p and Rev3p in the same mutagenic pathway. Based on these results, we propose that the response of cell cycle-arrested cells to an excess of exo- or endogenously induced DNA damage includes a novel replication

  6. Eriodictyol-induced anti-cancer and apoptotic effects in human hepatocellular carcinoma cells are associated with cell cycle arrest and modulation of apoptosis-related proteins

    Directory of Open Access Journals (Sweden)

    Fang Wang

    2016-06-01

    Full Text Available The objective of the present study was to investigate the anti-cancer effects of eriodictyol in human hepatocellular carcinoma cells (Hep-G2 and normal liver hepatocyte cell line (AML12 along with evaluating its mode of action. Sulforhodamine B assay was used to evaluate the cytotoxic effect of the compound while as fluorescence microscopy was involved to demonstrate the effect of eriodictyol on cellular apoptosis. Flow cytometry was used to investigate the effect of eriodictyol on cell cycle while Western blot analysis revealed the effect on apoptosis-related protein expressions. Results indicate that eriodictyol-induced selective and concentration-dependent cytotoxic effect on Hep-G2 cancer cells while AML12 normal liver cells were very less susceptible to its effect. Eriodictyol-induced apoptosis related morphological changes including chromatin condensation and nuclear fragmentation. It also induced G2/M cell cycle arrest in these cells. Eriodictyol led to up-regulation of Bax and PARP and down-regulation of Bcl-2 protein.

  7. Inhibition of mTORC2 Induces Cell-Cycle Arrest and Enhances the Cytotoxicity of Doxorubicin by Suppressing MDR1 Expression in HCC Cells

    Science.gov (United States)

    Chen, Bryan Wei; Chen, Wei; Liang, Hui; Liu, Hao; Liang, Chao; Zhi, Xiao; Hu, Li-qiang; Yu, Xia-Zhen; Wei, Tao; Ma, Tao; Xue, Fei; Zheng, Lei; Zhao, Bin; Feng, Xin-Hua; Bai, Xue-li; Liang, Ting-bo

    2016-01-01

    mTOR is aberrantly activated in hepatocellular carcinoma (HCC) and plays pivotal roles in tumorigenesis and chemoresistance. Rapamycin has been reported to exert antitumor activity in HCC and sensitizes HCC cells to cytotoxic agents. However, due to feedback activation of AKT after mTOR complex 1 (mTORC1) inhibition, simultaneous targeting of mTORC1/2 may be more effective. In this study, we examined the interaction between the dual mTORC1/2 inhibitor OSI-027 and doxorubicin in vitro and in vivo. OSI-027 was found to reduce phosphorylation of both mTORC1 and mTORC2 substrates, including 4E-BP1, p70S6K, and AKT (Ser473), and inhibit HCC cell proliferation. Similar to OSI-027 treatment, knockdown of mTORC2 induced G0–G1 phase cell-cycle arrest. In contrast, rapamycin or knockdown of mTORC1 increased phosphorylation of AKT (Ser473), yet had little antiproliferative effect. Notably, OSI-027 synergized with doxorubicin for the antiproliferative efficacy in a manner dependent of MDR1 expression in HCC cells. The synergistic antitumor effect of OSI-027 and doxorubicin was also observed in a HCC xenograft mouse model. Moreover, AKT was required for OSI-027–induced cell-cycle arrest and downregulation of MDR1. Our findings provide a rationale for dual mTORC1/mTORC2 inhibitors, such as OSI-027, as monotherapy or in combination with cytotoxic agents to treat HCC. PMID:26026051

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

    Directory of Open Access Journals (Sweden)

    Yong-sen Jia

    2015-01-01

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

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

    Science.gov (United States)

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

    2015-01-01

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

  10. The depletion of interleukin-8 causes cell cycle arrest and increases the efficacy of docetaxel in breast cancer cells.

    Science.gov (United States)

    Shao, Nan; Chen, Liu-Hua; Ye, Run-Yi; Lin, Ying; Wang, Shen-Ming

    2013-02-15

    IL-8 is a multi-functional pro-inflammatory chemokine, which is highly expressed in cancers, such as ER-negative breast cancer. The present study demonstrates the pervasive role of IL-8 in the malignant progression of ER-negative breast cancer. IL-8 siRNA inhibited proliferation and delayed the G1 to S cell cycle progression in MDA-MB-231 and BT549 cells. IL-8 silencing resulted in the upregulation of the CDK inhibitor p27, the downregulation of cyclin D1, and the reduction of phosphorylated-Akt and NF-κB activities. IL-8 depletion also increased the chemosensitivity to docetaxel. These results indicate a role for IL-8 in promoting tumor cell survival and resistance to docetaxel and highlight the potential therapeutic significance of IL-8 depletion in ER-negative breast cancer patients.

  11. Induction of G1 and G2/M cell cycle arrests by the dietary compound 3,3'-diindolylmethane in HT-29 human colon cancer cells

    Directory of Open Access Journals (Sweden)

    Choi Hyun

    2009-05-01

    Full Text Available Abstract Background 3,3'-Diindolylmethane (DIM, an indole derivative produced in the stomach after the consumption of broccoli and other cruciferous vegetables, has been demonstrated to exert anti-cancer effects in both in vivo and in vitro models. We have previously determined that DIM (0 – 30 μmol/L inhibited the growth of HT-29 human colon cancer cells in a concentration-dependent fashion. In this study, we evaluated the effects of DIM on cell cycle progression in HT-29 cells. Methods HT-29 cells were cultured with various concentrations of DIM (0 – 30 μmol/L and the DNA was stained with propidium iodide, followed by flow cytometric analysis. [3H]Thymidine incorporation assays, Western blot analyses, immunoprecipitation and in vitro kinase assays for cyclin-dependent kinase (CDK and cell division cycle (CDC2 were conducted. Results The percentages of cells in the G1 and G2/M phases were dose-dependently increased and the percentages of cells in S phase were reduced within 12 h in DIM-treated cells. DIM also reduced DNA synthesis in a dose-dependent fashion. DIM markedly reduced CDK2 activity and the levels of phosphorylated retinoblastoma proteins (Rb and E2F-1, and also increased the levels of hypophosphorylated Rb. DIM reduced the protein levels of cyclin A, D1, and CDK4. DIM also increased the protein levels of CDK inhibitors, p21CIP1/WAF1 and p27KIPI. In addition, DIM reduced the activity of CDC2 and the levels of CDC25C phosphatase and cyclin B1. Conclusion Here, we have demonstrated that DIM induces G1 and G2/M phase cell cycle arrest in HT-29 cells, and this effect may be mediated by reduced CDK activity.

  12. P53-mediated cell cycle arrest and apoptosis through a caspase-3-independent, but caspase-9-dependent pathway in oridonin-treated MCF-7 human breast cancer cells

    Institute of Scientific and Technical Information of China (English)

    Qiao CUI; Jing-hua YU; Jin-nan WU; Shin-ichi TASHIRO; Satoshi ONODERA; Mutsuhiko MINAMI; Takashi IKEJIMA

    2007-01-01

    Aim: To study the caspase-3-independent mechanisms in oridonin-induced MCF-7 human breast cancer cell apoptosis in vitro. Methods: The viability of oridonin-treated MCF-7 cells was measured by MTT (thiazole blue) assay. Apoptotic cells with condensed nuclei were visualized by phase contrast microscopy. Nucleoso-mal DNA fragmentation was assayed by agarose gel electrophoresis. The apoptotic ratio was determined by lactate dehydrogenase assay. Cell cycle alternation and mitochondrial membrane potential were measured by flow cytometric analysis. Bax, Bcl-2, caspase-3, caspase-9, heat shock protein (Hsp)90, p53, p-p53, p21, Poly (ADP-ribose) polymerase (PARP), and the inhibitor of caspase-activated Dnase (ICAD) protein expressions were detected by Western blot analysis. Results: Oridonin inhibited cell growth in a time- and dose-dependent manner. Cell cycle was altered through the upregulation of p53 and p21 protein expressions. Pan-caspase inhibitor Z-VAD-fmk and calpain inhibitor Ⅱ both decreased cell death ratio. Nucleosomal DNA fragmentation and the downregulation of △ψmit were detected in oridonin-induced MCF-7 cell apoptosis, which was involved in a postmitochondrial caspase-9-dependent pathway. Decreased Bcl-2 and Hsp90 expression levels and increased Bax and p21 expression levels were positively correlated with elevated levels of phosphorylated p53 phosphorylation. Moreover, PARP was partially cleaved by calpain rather than by capase-3. Conclusion: DNA damage provoked alternations in the mitochondrial and caspase-9 pathways as well as p53-mediated cell cycle arrest, but was not related to caspase-3 activity in oridonin-induced MCF-7 cells.

  13. Induction of Cell Cycle Arrest and Apoptotic Response of Head and Neck Squamous Carcinoma Cells (Detroit 562) by Caffeic Acid and Caffeic Acid Phenethyl Ester Derivative

    Science.gov (United States)

    Tanasiewicz, Marta

    2017-01-01

    Natural polyphenols have been observed to possess antiproliferative properties. The effects, including apoptotic potential of bioactive phenolic compounds, caffeic acid (CA) and its derivative caffeic acid phenethyl ester (CAPE), on cell proliferation and apoptosis in human head and neck squamous carcinoma cells (HNSCC) line (Detroit 562) were investigated and compared. Cancer cells apoptosis rates and cell cycle arrests were analysed by flow cytometry. Exposure to CA and CAPE was found to result in a dose-dependent decrease in the viability of Detroit 562 cells at different levels. CA/CAPE treatment did significantly affect the viability of Detroit 562 cells (MTT results). CAPE-mediated loss of viability occurred at lower doses and was more pronounced, with the concentrations which inhibit the growth of cells by 50% estimated at 201.43 μM (CA) and 83.25 μM (CAPE). Dead Cell Assay with Annexin V labelling demonstrated that CA and CAPE treatment of Detroit 562 cells resulted in an induction of apoptosis at 50 μM and 100 μM doses. The rise of mainly late apoptosis was observed for 100 μM dose and CA/CAPE treatment did affect the distribution of cells in G0/G1 phase. A combination of different phenolic compounds, potentially with chemotherapeutics, could be considered as an anticancer drug. PMID:28167973

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

    Science.gov (United States)

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

    2015-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Fabiana F. Ferreira

    2015-01-01

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

  16. 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.

  17. AZD2014 Radiosensitizes Oral Squamous Cell Carcinoma by Inhibiting AKT/mTOR Axis and Inducing G1/G2/M Cell Cycle Arrest.

    Directory of Open Access Journals (Sweden)

    Chih-Chia Yu

    Full Text Available Oral squamous cell carcinoma (OSCC is one of the most common malignant neoplasms in Taiwan. Activation of the mTOR signaling pathway has been linked to decreased radiation responsiveness in human oral cancer, thus it limits efficacy of radiotherapy. To address this question, we investigated the effect of AZD2014, a novel small molecular ATP-competitive inhibitor of mTORC1 and mTORC2 kinase, as a radiosensitizer in primary OSCC and OSCC-derived cell line models.We isolated primary tumor cells from OSCC tissues and cell lines. AZD2014 was administered with and without ionizing radiation. The radiosensitizing effect of AZD2014 were then assessed using cell viability assays, clonogenic survival assays, and cell cycle analyses. Western blotting was used to detect protein expression.Combination treatment with AZD2014 and irradiation resulted in significant reduction in OSCC cell line and primary OSCC cell colony formation due to the enhanced inhibition of AKT and both mTORC1 and mTORC2 activity. Pre-treatment with AZD2014 in irradiated oral cancer cells induced tumor cell cycle arrest at the G1 and G2/M phases, which led to disruption of cyclin D1-CDK4 and cyclin B1-CDC2 complexes. Moreover, AZD2014 synergized with radiation to promote both apoptosis and autophagy by increasing caspase-3 and LC3 in primary OSCC cells.These findings suggest that in irradiated OSCC cells, co-treatment with AZD2014, which targets mTORC1 and mTORC2 blockade, is an effective radiosensitizing strategy for oral squamous cell carcinoma.

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

    Energy Technology Data Exchange (ETDEWEB)

    Piotrowska, Hanna; Myszkowski, Krzysztof; Ziółkowska, Alicja [Department of Toxicology, Poznan University of Medical Sciences, Poznan (Poland); Kulcenty, Katarzyna [Chair of Medical Biotechnology, Poznan University of Medical Sciences, Poznan (Poland); Wierzchowski, Marcin [Department of Chemical Technology of Drugs, Poznan University of Medical Sciences, Poznan (Poland); Kaczmarek, Mariusz [Department of Clinical Immunology, Poznan University of Medical Sciences, Poznan (Poland); Murias, Marek [Department of Toxicology, Poznan University of Medical Sciences, Poznan (Poland); Kwiatkowska-Borowczyk, Eliza [Chair of Medical Biotechnology, Poznan University of Medical Sciences, Poznan (Poland); Department of Cancer Diagnostics and Immunology, Greater Poland Cancer Centre, Poznan (Poland); Jodynis-Liebert, Jadwiga, E-mail: liebert@ump.edu.pl [Department of Toxicology, Poznan University of Medical Sciences, Poznan (Poland)

    2012-08-15

    In the screening studies, cytotoxicity of 12 methylated resveratrol analogues on 11 human cancer cell lines was examined. The most active compound 3,4,4′5-tetramethoxystilbene (DMU-212) and two ovarian cancer cell lines A-2780 (IC{sub 50} = 0.71 μM) and SKOV-3 (IC{sub 50} = 11.51 μM) were selected for further investigation. To determine the mechanism of DMU-212 cytotoxicity, its ability to induce apoptosis was examined. DMU-212 arrested cell cycle in the G2/M or G0/G1 phase which resulted in apoptosis of both cell lines. The expression level of 84 apoptosis-related genes was investigated. In SKOV-3 cells DMU-212 caused up-regulation of pro-apoptotic Bax, Apaf-1 and p53 genes, specific to intrinsic pathway of apoptosis, and a decrease in Bcl-2 and Bcl 2110 mRNA expressions. Conversely, in A-2780 cells an increased expression of pro-apoptotic genes Fas, FasL, TNF, TNFRSF10A, TNFRSF21, TNFRSF16 specific to extracellular mechanism of apoptosis was observed. There are no data published so far regarding the receptor mediated apoptosis induced by DMU-212. The activation of caspase-3/7 was correlated with decreased TRAF-1 and BIRC-2 expression level in A-2780 cells exposed to DMU-212. DMU-212 caused a decrease in CYP1A1 and CYP1B1 mRNA levels in A-2780 by 50% and 75%, and in SKOV-3 cells by 15% and 45%, respectively. The protein expression was also reduced in both cell lines. It is noteworthy that the expression of CYP1B1 protein was entirely inhibited in A-2780 cells treated with DMU-212. It can be suggested that different CYP1B1 expression patterns in either ovarian cell line may affect their sensitivity to cytotoxic activity of DMU-212. -- Highlights: ► DMU-212 was the most cytotoxic among 12 O-methylated resveratrol analogues. ► DMU-212 arrested cell cycle at G2/M and G0/G1phase ► DMU-212 triggered mitochondria- and receptor‐mediated apoptosis. ► DMU-212 entirely inhibited CYP1B1 protein expression in A-2780 cells.

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

    Science.gov (United States)

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

    2015-02-01

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

  20. Cucurbitacin B inhibits proliferation, induces G2/M cycle arrest and autophagy without affecting apoptosis but enhances MTT reduction in PC12 cells

    Directory of Open Access Journals (Sweden)

    Chuanhong Wu

    2016-03-01

    Full Text Available In the present study, the effect of cucurbitacin B (a natural product with anti-cancer effect was studied on PC12 cells. It significantly reduced the cell number, changed cell morphology and inhibited colony formation while MTT results showed increased cell viability. Cucurbitacin B treatment increased activity of succinode hydrogenase. No alteration in the integrity of mem-brane, the release of lactic dehydrogenase, the mitochondrial membrane potential, and the expression of apoptotic proteins suggested that cucurbitacin B did not induce apoptosis. The cell cycle was remarkably arrested at G2/M phase. Furthermore, cucurbitacin B induced autophagy as evidence by accumulation of autophagic vacuoles and the increase of LC3II. In addition, cucurbitacin B up-regulated the expression of p-beclin-1, p-ULK1, p-Wee1, p21 and down-regulated p-mTOR, p-p70S6K, CDC25C, CDK1, Cyclin B1. In conclusion, cucurbitacin B inhibited PC12 proliferation but caused MTT pitfall. Cucurbitacin B induced G2/M cell cycle arrest, autophagy, but not the apoptosis in PC12 cells.

  1. Myricetin and methyl eugenol combination enhances the anticancer activity, cell cycle arrest and apoptosis induction of cis-platin against HeLa cervical cancer cell lines.

    Science.gov (United States)

    Yi, Jin-Ling; Shi, Song; Shen, Yan-Li; Wang, Ling; Chen, Hai-Yan; Zhu, Jun; Ding, Yan

    2015-01-01

    Drug combination therapies are common practice in the treatment of cancer. In this study, we evaluated the anticancer effects of myricetin (MYR), methyl eugenol (MEG) and cisplatin (CP) both separately as well as in combination against cervical cancer (HeLa) cells. To demonstrate whether MYR and MEG enhance the anticancer activity of CP against cervical cancer cells, we treated HeLa cells with MYR and MEG alone or in combination with cisplatin and evaluated cell growth and apoptosis using MTT (3 (4, 5 dimethyl thiazol 2yl) 2, 5 diphenyltetrazolium bromide) assay, LDH release assay, flow cytometry and fluorescence microscopy. The results revealed that, as compared to single drug treatment, the combination of MYR or MEG with CP resulted in greater effect in inhibiting cancer cell growth and inducing apoptosis. Cell apoptosis induction, Caspase-3 activity, cell cycle arrest and mitochondrial membrane potential loss were systematically studied to reveal the mechanisms of synergy between MYR, MEG and CP. Combination of MYR or MEG with CP resulted in more potent apoptosis induction as revealed by fluorescence microscopy using Hoechst 33258 and AO-ETBR staining. The combination treatment also increased the number of cells in G0/G1 phase dramatically as compared to single drug treatment. Mitochondrial membrane potential loss (ΛΨm) as well as Caspase-3 activity was much higher in combination treatment as compared to single drug treatment. Findings of this investigation suggest that MYR and MEG combined with cisplatin is a potential clinical chemotherapeutic approach in human cervical cancer.

  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

    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......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...

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

    Science.gov (United States)

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

    2012-10-01

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

  4. Anaphase-promoting complex/cyclosome protein Cdc27 is a target for curcumin-induced cell cycle arrest and apoptosis

    Directory of Open Access Journals (Sweden)

    Lee Seung Joon

    2012-01-01

    Full Text Available Abstract Background Curcumin (diferuloylmethane, the yellow pigment in the Asian spice turmeric, is a hydrophobic polyphenol from the rhizome of Curcuma longa. Because of its chemopreventive and chemotherapeutic potential with no discernable side effects, it has become one of the major natural agents being developed for cancer therapy. Accumulating evidence suggests that curcumin induces cell death through activation of apoptotic pathways and inhibition of cell growth and proliferation. The mitotic checkpoint, or spindle assembly checkpoint (SAC, is the major cell cycle control mechanism to delay the onset of anaphase during mitosis. One of the key regulators of the SAC is the anaphase promoting complex/cyclosome (APC/C which ubiquitinates cyclin B and securin and targets them for proteolysis. Because APC/C not only ensures cell cycle arrest upon spindle disruption but also promotes cell death in response to prolonged mitotic arrest, it has become an attractive drug target in cancer therapy. Methods Cell cycle profiles were determined in control and curcumin-treated medulloblastoma and various other cancer cell lines. Pull-down assays were used to confirm curcumin binding. APC/C activity was determined using an in vitro APC activity assay. Results We identified Cdc27/APC3, a component of the APC/C, as a novel molecular target of curcumin and showed that curcumin binds to and crosslinks Cdc27 to affect APC/C function. We further provide evidence that curcumin preferably induces apoptosis in cells expressing phosphorylated Cdc27 usually found in highly proliferating cells. Conclusions We report that curcumin directly targets the SAC to induce apoptosis preferably in cells with high levels of phosphorylated Cdc27. Our studies provide a possible molecular mechanism why curcumin induces apoptosis preferentially in cancer cells and suggest that phosphorylation of Cdc27 could be used as a biomarker to predict the therapeutic response of cancer cells to

  5. ETME, a novel β-elemene derivative, synergizes with arsenic trioxide in inducing apoptosis and cell cycle arrest in hepatocarcinoma cells via a p53-dependent pathway

    Directory of Open Access Journals (Sweden)

    Zhiying Yu

    2014-12-01

    Full Text Available Arsenic trioxide (ATO has been identified as an effective treatment for acute promyelocytic leukemia (APL but is much less effective against solid tumors such as hepatocellular carcinoma (HCC. In the search for ways to enhance its therapeutic efficacy against solid tumors, we have examined its use in combination with a novel derivative of β-elemene, N-(β-elemene-13-yltryptophan methyl ester (ETME. Here we report the effects of the combination on cell viability, apoptosis, the cell cycle and mitochondria membrane potential (MMP in HCC SMMC-7721 cells. We found that the two compounds acted synergistically to enhance antiproliferative activity and apoptosis. The combination also decreased the MMP, down-regulated Bcl-2 and pro-proteins of the caspase family, and up-regulated Bax and BID, all of which were reversed by the p53 inhibitor, pifithrin-α. In addition, the combination induced cell cycle arrest at the G2/M phase and reduced tumor volume and weight in an xenograft model of nude mice. Overall, the results suggest that ETME in combination with ATO may be useful in the treatment of HCC patients particularly those unresponsive to ATO alone.

  6. Silencing livin gene by siRNA leads to apoptosis induction, cell cycle arrest, and proliferation inhibition in malignant melanoma LiBr cells

    Institute of Scientific and Technical Information of China (English)

    Hao WANG; Sheng-shun TAN; Xin-yang WANG; Dong-hua LIU; Chun-shui YU; Zhuan-li BAI; Da-lin HE; Jun ZHAO

    2007-01-01

    Aim: The aim of the present study was to investigate the effects of silencing the livin gene by small interfering RNA (siRNA) on the expression of livin and the effects on apoptosis, cell cycle, and proliferation in human malignant melanoma LiBr cells. Methods: Three chemically-synthetic siRNA duplexes targeting livin were transiently transfected into the LiBr cells, and the effects on livin expression were detected both at the mRNA level by real-time RT-PCR and at the protein level by Western blotting. Apoptosis was evaluated by terminal deoxynucleotidyl transferase-mediated digoxigenin-dUTP nick-end labeling assay, flow cytometric analysis, and the expression of procaspase-3 and activated caspase-3 analysis by Western blotting. Cell cycle was analyzed by flow cytometry. Cell proliferation was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide. Results: One of the 3 designed siRNA could effectively knock down the livin expression both at the mRNA and protein levels in dose- and time-dependent manners; 100 nmol/L with maximum downregulation on mRNA at 48 h, and on the protein at 72 h after transfection. Silencing livin could significantly induce apoptosis, arrest cell cycle at the GJG1 phase, and inhibit proliferation in LiBr cells. Meanwhile, caspase-3 was activated. Conclusion: The livin gene could serve as a potential molecular target for gene therapy by siRNA for malignant melanoma.

  7. Ezh1 is required for hematopoietic stem cell maintenance and prevents senescence-like cell cycle arrest.

    Science.gov (United States)

    Hidalgo, Isabel; Herrera-Merchan, Antonio; Ligos, Jose Manuel; Carramolino, Laura; Nuñez, Javier; Martinez, Fernando; Dominguez, Orlando; Torres, Miguel; Gonzalez, Susana

    2012-11-02

    Polycomb group (PcG) proteins are key epigenetic regulators of hematopietic stem cell (HSC) fate. The PcG members Ezh2 and Ezh1 are important determinants of embryonic stem cell identity, and the transcript levels of these histone methyltransferases are inversely correlated during development. However, the role of Ezh1 in somatic stem cells is largely unknown. Here we show that Ezh1 maintains repopulating HSCs in a slow-cycling, undifferentiated state, protecting them from senescence. Ezh1 ablation induces significant loss of adult HSCs, with concomitant impairment of their self-renewal capacity due to a potent senescence response. Epigenomic and gene expression changes induced by Ezh1 deletion in senesced HSCs demonstrated that Ezh1-mediated PRC2 activity catalyzes monomethylation and dimethylation of H3K27. Deletion of Cdkn2a on the Ezh1 null background rescued HSC proliferation and survival. Our results suggest that Ezh1 is an important histone methyltransferase for HSC maintenance.

  8. The pleiotropic effects of fisetin and hesperetin on human acute promyelocytic leukemia cells are mediated through apoptosis, cell cycle arrest, and alterations in signaling networks.

    Science.gov (United States)

    Adan, Aysun; Baran, Yusuf

    2015-11-01

    Fisetin and hesperetin, flavonoids from various plants, have several pharmaceutical activities including antioxidative, anti-inflammatory, and anticancer effects. However, studies elucidating the role and the mechanism(s) of action of fisetin and hesperetin in acute promyelocytic leukemia are absent. In this study, we investigated the mechanism of the antiproliferative and apoptotic actions exerted by fisetin and hesperetin on human HL60 acute promyelocytic leukemia cells. The viability of HL60 cells was evaluated using the MTT assay, apoptosis by annexin V/propidium iodide (PI) staining and cell cycle distribution using flow cytometry, and changes in caspase-3 enzyme activity and mitochondrial transmembrane potential. Moreover, we performed whole-genome microarray gene expression analysis to reveal genes affected by fisetin and hesperetin that can be important for developing of future targeted therapy. Based on data obtained from microarray analysis, we also described biological networks modulated after fisetin and hesperetin treatment by KEGG and IPA analysis. Fisetin and hesperetin treatment showed a concentration- and time-dependent inhibition of proliferation and induced G2/M arrest for both agents and G0/G1 arrest for hesperetin at only the highest concentrations. There was a disruption of mitochondrial membrane potential together with increased caspase-3 activity. Furthermore, fisetin- and hesperetin-triggered apoptosis was confirmed by annexin V/PI analysis. The microarray gene profiling analysis revealed some important biological pathways including mitogen-activated protein kinases (MAPK) and inhibitor of DNA binding (ID) signaling pathways altered by fisetin and hesperetin treatment as well as gave a list of genes modulated ≥2-fold involved in cell proliferation, cell division, and apoptosis. Altogether, data suggested that fisetin and hesperetin have anticancer properties and deserve further investigation.

  9. Anti-proliferative properties of commercial Pelargonium sidoides tincture, with cell-cycle G0/G1 arrest and apoptosis in Jurkat leukaemia cells.

    Science.gov (United States)

    Pereira, Andreia; Bester, Megan; Soundy, Puffy; Apostolides, Zeno

    2016-09-01

    Context Pelargonium sidoides DC (Geraniaceae) is an important medicinal plant indigenous to South Africa and Lesotho. Previous studies have shown that root extracts are rich in polyphenolic compounds with antibacterial, antiviral and immunomodulatory activities. Little is known regarding the anticancer properties of Pelargonium sidoides extracts. Objective This study evaluates the anti-proliferative effects of a Pelargonium sidoides radix mother tincture (PST). Materials and methods The PST was characterized by LC-MS/MS. Anti-proliferative activity was evaluated in the pre-screen panel of the National Cancer Institute (NCI-H460, MCF-7 and SF-268) and the Jurkat leukaemia cell line at concentrations of 0-150 μg/mL. The effect on cell growth was determined with sulphorhodamine B and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assays after 72 h. The effect on cell cycle and apoptosis induction in Jurkat cells was determined by flow cytometry with propidium iodide and Annexin V: fluorescein isothiocyanate staining. Results Dihydroxycoumarin sulphates, gallic acid as well as gallocatechin dimers and trimers were characterized in PST by mass spectrometry. Moderate anti-proliferative effects with GI50 values between 40 and 80 μg/mL were observed in the NCI-pre-screen panel. Strong activity observed with Jurkat cells with a GI50 value of 6.2 μg/mL, significantly better than positive control 5-fluorouracil (GI50 value of 9.7 μg/mL). The PST arrested Jurkat cells at the G0/G1 phase of the cell cycle and increased the apoptotic cells from 9% to 21%, while the dead cells increased from 4% to 17%. Conclusion We present evidence that P. sidoides has cancer cell type-specific anti-proliferative effects and may be a source of novel anticancer molecules.

  10. Rapamycin reverses NPM-ALK-induced glucocorticoid resistance in lymphoid tumor cells by inhibiting mTOR signaling pathway, enhancing G1 cell cycle arrest and apoptosis.

    Science.gov (United States)

    Gu, L; Gao, J; Li, Q; Zhu, Y P; Jia, C S; Fu, R Y; Chen, Y; Liao, Q K; Ma, Z

    2008-11-01

    The anaplastic lymphoma kinase (ALK) is an oncogene product involved in hematopoietic and non-hematopoietic malignancies. Recent studies have demonstrated that nucleophosmin (NPM)-ALK, originated from the fusion of NPM and ALK genes, causes cell transformation through diverse mechanisms. Here, we show a novel mechanism by which NPM-ALK transforms lymphoid tumor cells to become resistant to glucocorticoid (GC) or dexamethasone (Dex) treatment. Transformed BaF3 cells by NPM-ALK were much more resistant to Dex compared with their parental cells, and concurrently had a constitutive activation of mammalian target of rapamycin (mTOR) signaling, as evidenced by hyperphosphorylation of its downstream effectors, p70 S6 kinase (p70S6K) and eukaryotic initiation factor 4E-binding protein 1 (4E-BP1). The mTOR inhibitor rapamycin suppressed activation of p70S6K in BaF3/NPM-ALK cells and reversed GC resistance by synergistically inhibiting mTOR signaling pathway, enhancing cell cycle arrest at G(1) phase and promoting apoptotic cell death. In conclusion, our data indicate that the ALK fusion kinase, NPM-ALK, induces GC resistance by activating mTOR signaling, and addition of mTOR inhibitors to the chemotherapeutic regimen of ALK+ lymphomas may improve the prognosis.

  11. Fucoidan induces G1 arrest of the cell cycle in EJ human bladder cancer cells through down-regulation of pRB phosphorylation

    Directory of Open Access Journals (Sweden)

    Hye Young Park

    2015-06-01

    Full Text Available AbstractFucoidan, a sulfated polysaccharide found in marine algae and brown seaweeds, has been shown to inhibit the in vitro growth of human cancer cells. This study was conducted in cultured human bladder cancer EJ cells to elucidate the possible mechanisms by which fucoidan exerts its anti-proliferative activity, which until now has remained poorly understood. Fucoidan treatment of EJ cells resulted in dose-dependent inhibition of cell growth and induced apoptotic cell death. Flow cytometric analysis revealed that fucoidan led to G1 arrest in cell cycle progression. It was associated with down-regulation of cyclin D1, cyclin E, and cyclin-dependent-kinases (Cdks in a concentration-dependent manner, without any change in Cdk inhibitors, such as p21 and p27. Furthermore, dephosphorylation of retinoblastoma protein (pRB by this compound was associated with enhanced binding of pRB with the transcription factors E2F-1 and E2F-4. Overall, our results demonstrate that fucoidan possesses anticancer activity potential against bladder cancer cells by inhibiting pRB phosphorylation.

  12. 2-Methoxy-4-vinylphenol can induce cell cycle arrest by blocking the hyper-phosphorylation of retinoblastoma protein in benzo[a]pyrene-treated NIH3T3 cells

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Jin Boo [Bioresource Sciences, Andong National University, Andong 760749 (Korea, Republic of); Jeong, Hyung Jin, E-mail: jhj@andong.ac.kr [Bioresource Sciences, Andong National University, Andong 760749 (Korea, Republic of)

    2010-10-01

    Research highlights: {yields} 2M4VP activated the expression of p21 and p15 protein, and down-regulated the expression of cyclin D1 and cyclin E. {yields} 2M4VP inhibited hyper-phosphorylation of Rb protein. {yields} 2M4VP induced cell cycle arrest from G1 to S. {yields} 2M4VP inhibited hyper-proliferation of the cells in BaP-treated cells. {yields} 2M4VP induces growth arrest of BaP-treated cells by blocking hyper-phosphorylation of Rb via regulating the expression of cell cycle-related proteins. -- Abstract: Benzo[a]pyrene (BaP) is an environment carcinogen that can enhance cell proliferation by disturbing the signal transduction pathways in cell cycle regulation. In this study, the effects of 2M4VP on cell proliferation, cell cycle and cell cycle regulatory proteins were studied in BaP-treated NIH 3T3 cells to establish the molecular mechanisms of 2M4VP as anti-proliferative agents. 2M4VP exerted a dose-dependent inhibitory effect on cell growth correlated with a G1 arrest. Analysis of G1 cell cycle regulators expression revealed 2M4VP increased expression of CDK inhibitor, p21Waf1/Cip1 and p15 INK4b, decreased expression of cyclin D1 and cyclin E, and inhibited kinase activities of CDK4 and CDK2. However, 2M4VP did not affect the expression of CDK4 and CDK2. Also, 2M4VP inhibited the hyper-phosphorylation of Rb induced by BaP. Our results suggest that 2M4VP induce growth arrest of BaP-treated NIH 3T3 cells by blocking the hyper-phosphorylation of Rb via regulating the expression of cell cycle-related proteins.

  13. Curcumin inhibits growth potential by G1 cell cycle arrest and induces apoptosis in p53-mutated COLO 320DM human colon adenocarcinoma cells.

    Science.gov (United States)

    Dasiram, Jade Dhananjay; Ganesan, Ramamoorthi; Kannan, Janani; Kotteeswaran, Venkatesan; Sivalingam, Nageswaran

    2017-02-01

    Curcumin, a natural polyphenolic compound and it is isolated from the rhizome of Curcuma longa, have been reported to possess anticancer effect against stage I and II colon cancer. However, the effect of curcumin on colon cancer at Dukes' type C metastatic stage III remains still unclear. In the present study, we have investigated the anticancer effects of curcumin on p53 mutated COLO 320DM human colon adenocarcinoma cells derived from Dukes' type C metastatic stage. The cellular viability and proliferation were assessed by trypan blue exclusion assay and MTT assay, respectively. The cytotoxicity effect was examined by lactate dehydrogenase (LDH) cytotoxicity assay. Apoptosis was analyzed by DNA fragmentation analysis, Hoechst and propidium iodide double fluorescent staining and confocal microscopy analysis. Cell cycle distribution was performed by flow cytometry analysis. Here we have observed that curcumin treatment significantly inhibited the cellular viability and proliferation potential of p53 mutated COLO 320DM cells in a dose- and time-dependent manner. In addition, curcumin treatment showed no cytotoxic effects to the COLO 320DM cells. DNA fragmentation analysis, Hoechst and propidium iodide double fluorescent staining and confocal microscopy analysis revealed that curcumin treatment induced apoptosis in COLO 320DM cells. Furthermore, curcumin caused cell cycle arrest at the G1 phase, decreased the cell population in the S phase and induced apoptosis in COLO 320DM colon adenocarcinoma cells. Together, these data suggest that curcumin exerts anticancer effects and induces apoptosis in p53 mutated COLO 320DM human colon adenocarcinoma cells derived from Dukes' type C metastatic stage.

  14. The DNA-mismatch repair enzyme hMSH2 modulates UV-B-induced cell cycle arrest and apoptosis in melanoma cells.

    Science.gov (United States)

    Seifert, Markus; Scherer, Stefan J; Edelmann, Wilfried; Böhm, Markus; Meineke, Viktor; Löbrich, Markus; Tilgen, Wolfgang; Reichrath, Jörg

    2008-01-01

    The mechanisms by which the post-replicative DNA mismatch repair (MMR) enzyme MSH2 is involved in the complex response mechanisms to UV damage are yet to be clarified. Here, we show increased levels of MSH2 mRNA in malignant melanoma, metastases of melanoma, and melanoma cell (MeWo) lines as compared with melanocytic nevi or primary cultured benign melanocytes. UV-B treatment modulated MSH2 expression and silencing of MSH2 gene expression using small interfering RNA technology regulated UV-B-induced cell cycle arrest and apoptosis in human MeWo. We show that MSH2-deficient non-malignant mouse fibroblasts (MEF-/-) are partially resistant against UV-B-induced apoptosis and show reduced S-Phase accumulation. In addition, we show that an Msh2 point mutation (MEFGA) that affects MMR does not affect UV-B-induced apoptosis. In conclusion, we demonstrate that MSH2 modulates in human melanocytes both UV-B-induced cell cycle regulation and apoptosis, most likely via independent, uncoupled mechanisms.

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

    Directory of Open Access Journals (Sweden)

    Yuxian Bai

    2013-01-01

    Full Text Available In this study, the anticancer activity of chamaejasmine was characterized in the human breast cancer cell line, MDA-MB-231. Cell viability and cell cycle distribution were determined by MTT assay and flow cytometry, respectively. Western blotting was performed to determine changes in levels of various proteins. Results showed that treatment with chamaejasmine (4–16 μM inhibited cell proliferation, which correlated with G2/M phase arrest and apoptosis in MDA-MB-231 cells. Chamaejasmine treatment of MDA-MB-231 cells resulted in induction of WAF1/p21 and KIP1/p27, decrease in cyclins A and cyclins B1. Cyclin-dependent kinase (cdk 2 and cdc2 was also decreased after chamaejasmine treatment. Moreover, inhibition of nuclear translocation, phosphorylation of NF-κB, activation of IKKα and IKKβ, inhibition of phosphorylation and degradation of IκBα were also detected in this work. Our findings suggested that chamaejasmine could be explored as a preventive and perhaps as a chemotherapeutic agent in the management of breast cancer.

  16. Antiproliferative activity of Alisol B in MDA-MB-231 cells is mediated by apoptosis, dysregulation of mitochondrial functions, cell cycle arrest and generation of reactive oxygen species.

    Science.gov (United States)

    Zhang, Aifeng; Sheng, Yuqing; Zou, Mingchang

    2017-03-01

    Previous studies have demonstrated that Alisol B has inhibitory activity in cancer cells. However, the exact mechanism through which inhibition is achieved is still poorly understood. In the present study, the authors examined the effects of Alisol B in human breast cancer cells. Alisol B showed significant anticancer activity in MDA-MB-231 cells. The results demonstrated that the cytotoxicity induced by Alisol B was mediated by induction of apoptosis, decrease in mitochondrial membrane potential, cell cycle arrest, activation of caspases and accumulation of ROS (reactive oxygen species) level. Interestingly, pretreatment of cells with the general caspase inhibitor z-VAD-FMK significantly prevented Alisol B-induced apoptosis. Furthermore, western blot analysis revealed the upregulation of p-p38 and downregulation of p-AKT, p-p65 and p-mTOR. Taken together, the above results suggest that Alisol B suppresses the growth of MDA-MB-231 cells mainly through induction of apoptosis; this outcome may represent the major mechanism of Alisol B-mediated apoptosis.

  17. Nexrutine inhibits survival and induces G1 cell cycle arrest, which is associated with apoptosis or autophagy depending on the breast cancer cell line.

    Science.gov (United States)

    Yan, Guang; Lanza-Jacoby, Susan; Wang, Chenguang

    2014-01-01

    Breast cancers that are estrogen receptor (ER) negative or are ER negative with ErbB2/HER-2 overexpression have a poor prognosis, which emphasizes the importance of developing compounds for preventing breast cancer. Nexrutine, an herbal extract from the plant Phellodendron amurense, has been used for centuries in Asian medicine to treat inflammation, gastroenteritis, abdominal pain, and diarrhea. In this study we investigated the anticancer effects of Nexrutine on ER negative breast cancer cell lines that are positive or negative for HER-2. Nexrutine decreased the activities of 2 potential targets of breast cancer, cyclooxygenase (COX)-2, and peroxisome proliferators activated receptor gamma (PPARγ). The antiinflammatory effects of Nexrutine were evident with decreased prostaglandin (PG)E2 production, protein expression of microsomal PGE2 synthase (mPGES), and PPARγ. Nexrutine decreased cell survival and induced a G1 cell cycle arrest in SkBr3 and MDA-MB 231 cells, which were associated with reduced protein expression of Cyclin D1 and cdk2 along with increased protein expression of p21 and p27. The growth-inhibitory effect of Nexrutine was associated with apoptosis in SkBr3 cells and autophagy in MDA-MB231 cells. Based on these findings, we propose that Nexrutine may provide a novel approach for protection against breast cancer.

  18. Xanthatin Induces Cell Cycle Arrest at G2/M Checkpoint and Apoptosis via Disrupting NF-κB Pathway in A549 Non-Small-Cell Lung Cancer Cells

    Directory of Open Access Journals (Sweden)

    Yin Lu

    2012-03-01

    Full Text Available Xanthatin, a natural sesquiterpene lactone, has significant antitumor activity against a variety of cancer cells, yet little is known about its anticancer mechanism. In this study, we demonstrated that xanthatin had obvious dose-/time-dependent cytotoxicity against the human non-small-cell lung cancer (NSCLC cell line A549. Flow cytometry analysis showed xanthatin induced cell cycle arrest at G2/M phase. Xanthatin also had pro-apoptotic effects on A549 cells as evidenced by Hoechst 33258 staining and annexin V-FITC staining. Mechanistic data revealed that xanthatin downregulated Chk1, Chk2, and phosphorylation of CDC2, which contributed to the cell cycle arrest. Xathatin also increased total p53 protein levels, decreased Bcl-2/Bax ratio and expression of the downstream factors procaspase-9 and procaspase-3, which triggered the intrinsic apoptosis pathway. Furthermore, xanthatin blocked phosphorylation of NF-κB (p65 and IκBa, which might also contribute to its pro-apoptotic effects on A549 cells. Xanthatin also inhibited TNFa induced NF-κB (p65 translocation. We conclude that xanthatin displays significant antitumor effects through cell cycle arrest and apoptosis induction in A549 cells. These effects were associated with intrinsic apoptosis pathway and disrupted NF-κB signaling. These results suggested that xanthatin may have therapeutic potential against NSCLC.

  19. Differential biologic effects of CPD and 6-4PP UV-induced DNA damage on the induction of apoptosis and cell-cycle arrest

    Directory of Open Access Journals (Sweden)

    Yasui Akira

    2005-10-01

    Full Text Available Abstract Background UV-induced damage can induce apoptosis or trigger DNA repair mechanisms. Minor DNA damage is thought to halt the cell cycle to allow effective repair, while more severe damage can induce an apoptotic program. Of the two major types of UV-induced DNA lesions, it has been reported that repair of CPD, but not 6-4PP, abrogates mutation. To address whether the two major forms of UV-induced DNA damage, can induce differential biological effects, NER-deficient cells containing either CPD photolyase or 6-4 PP photolyase were exposed to UV and examined for alterations in cell cycle and apoptosis. In addition, pTpT, a molecular mimic of CPD was tested in vitro and in vivo for the ability to induce cell death and cell cycle alterations. Methods NER-deficient XPA cells were stably transfected with CPD-photolyase or 6-4PP photolyase to specifically repair only CPD or only 6-4PP. After 300 J/m2 UVB exposure photoreactivation light (PR, UVA 60 kJ/m2 was provided for photolyase activation and DNA repair. Apoptosis was monitored 24 hours later by flow cytometric analysis of DNA content, using sub-G1 staining to indicate apoptotic cells. To confirm the effects observed with CPD lesions, the molecular mimic of CPD, pTpT, was also tested in vitro and in vivo for its effect on cell cycle and apoptosis. Results The specific repair of 6-4PP lesions after UVB exposure resulted in a dramatic reduction in apoptosis. These findings suggested that 6-4PP lesions may be the primary inducer of UVB-induced apoptosis. Repair of CPD lesions (despite their relative abundance in the UV-damaged cell had little effect on the induction of apoptosis. Supporting these findings, the molecular mimic of CPD, (dinucleotide pTpT could mimic the effects of UVB on cell cycle arrest, but were ineffective to induce apoptosis. Conclusion The primary response of the cell to UV-induced 6-4PP lesions is to trigger an apoptotic program whereas the response of the cell to CPD

  20. 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.

  1. XRCC1 deficiency increased the DNA damage induced by γ-ray in HepG2 cell: Involvement of DSB repair and cell cycle arrest.

    Science.gov (United States)

    Niu, Yujie; Zhang, Xing; Zheng, Yuxin; Zhang, Rong

    2013-09-01

    γ-ray irradiation can induce DNA damages which include base damages, single-strand breaks and double-strand breaks in various type cells. The DNA repair protein XRCC1, as a part of the BER pathway, forms complexes with DNA polymerase beta, DNA ligase III and poly-ADP-ribose polymerase (PARP) in the repair of DNA single strand breaks and also affects the repair of double strand breaks. However, it is still not known well whether XRCC1 contributes to affect the irradiation sensitivity and DNA damage in HepG2 cell and the potential mechanism. Hence, the purpose of this study was to explore whether abrogation of XRCC1 gene expression by shRNA could reduce DNA repair and thus sensitize HepG2 cells to γ-ray. Cell viability was measured by Trypan blue staining and cloning efficiency assay. The DNA damage was detected by Comet assay. Apoptosis and cell cycle were detected by flow cytometry. The DNA-PKcs and gadd153 mRNA expression were determined by Real-time PCR. Our results showed that abrogation of XRCC 1 could sensitize HepG2 cells to γ-ray. This enhanced sensitivity could be attributed to the increased DNA damage and increased cell cycle arrest, which might be related with the increasing of DNA-PKcs and gadd153 mRNA expression. Therefore, our results suggested that the γ-ray irradiation sensitivity could be increased by targeting inhibition of XRCC1 in HepG2 cell.

  2. Mitotic Stress Is an Integral Part of the Oncogene-Induced Senescence Program that Promotes Multinucleation and Cell Cycle Arrest

    Directory of Open Access Journals (Sweden)

    Dina Dikovskaya

    2015-09-01

    Full Text Available Oncogene-induced senescence (OIS is a tumor suppression mechanism that blocks cell proliferation in response to oncogenic signaling. OIS is frequently accompanied by multinucleation; however, the origin of this is unknown. Here, we show that multinucleate OIS cells originate mostly from failed mitosis. Prior to senescence, mutant H-RasV12 activation in primary human fibroblasts compromised mitosis, concordant with abnormal expression of mitotic genes functionally linked to the observed mitotic spindle and chromatin defects. Simultaneously, H-RasV12 activation enhanced survival of cells with damaged mitoses, culminating in extended mitotic arrest and aberrant exit from mitosis via mitotic slippage. ERK-dependent transcriptional upregulation of Mcl1 was, at least in part, responsible for enhanced survival and slippage of cells with mitotic defects. Importantly, mitotic slippage and oncogene signaling cooperatively induced senescence and key senescence effectors p21 and p16. In summary, activated Ras coordinately triggers mitotic disruption and enhanced cell survival to promote formation of multinucleate senescent cells.

  3. Beryllium sulfate induces p21 CDKN1A expression and a senescence-like cell cycle arrest in susceptible cancer cell types.

    Science.gov (United States)

    Gorjala, Priyatham; Gary, Ronald K

    2010-12-01

    In fibroblasts, beryllium salt causes activation of the p53 transcription factor and induction of a senescence-like state. It is not known whether Be(2+) can affect the proliferation of cancer cells, which are generally unsusceptible to senescence. A172 glioblastoma and RKO colon carcinoma cell lines each have wildtype p53, so these cell types have the potential to be responsive to agents that activate p53. In A172 cells, BeSO(4) produced a G(0)/G(1)-phase cell cycle arrest and increased expression of senescence-associated β-galactosidase, an enzymatic marker of senescence. BeSO(4) caused phosphorylation of serine-15 of p53, accumulation of p53 protein, and expression of p21, the cyclin-dependent kinase inhibitor that is prominent during senescence. BeSO(4) inhibited A172 growth with an IC(50) = 4.7 μM in a 6-day proliferation assay. In contrast, BeSO(4) had no effect on RKO cells, even though Be(2+) uptake was similar for the two cell types. This differential responsiveness marks BeSO(4) as a reagent capable of activating a separable branch of the p53 signaling network. A172 and RKO cells are known to exhibit p53-dependent upregulation of p21 in response to DNA damage. The RKO cells produced high levels of p21 when exposed to DNA damaging agents, yet failed to express p21 when treated with BeSO(4). Conversely, BeSO(4) did not cause DNA damage in A172 cells, yet it was a potent inducer of p21 expression. These observations indicate that the growth control pathway affected by BeSO(4) is distinct from the DNA damage response pathway, even though both ultimately converge on p53 and p21.

  4. RNAi-mediated knockdown of catalase causes cell cycle arrest in SL-1 cells and results in low survival rate of Spodoptera litura (Fabricius.

    Directory of Open Access Journals (Sweden)

    Haiming Zhao

    Full Text Available Deregulated reactive oxygen species (ROS production can lead to the disruption of structural and functional integrity of cells as a consequence of reactive interaction between ROS and various biological components. Catalase (CAT is a common enzyme existing in nearly all organisms exposed to oxygen, which decomposes harmful hydrogen peroxide, into water and oxygen. In this study, the full length sequence that encodes CAT-like protein from Spodoptera litura named siltCAT (GenBank accession number: JQ_663444 was cloned and characterized. Amino acid sequence alignment showed siltCAT shared relatively high conservation with other insect, especially the conserved residues which defined heme and NADPH orientation. Expression pattern analysis showed that siltCAT mRNA was mainly expressed in the fat body, midgut, cuticle and malpighian tube, and as well as over last instar larvae, pupa and adult stages. RNA interference was used to silence CAT gene in SL-1 cells and the fourth-instar stage of S. litura larvae respectively. Our results provided evidence that CAT knockdown induced ROS generation, cell cycle arrest and apoptosis in SL-1 cells. It also confirmed the decrease in survival rate because of increased ROS production in experimental groups injected with double-stranded RNA of CAT (dsCAT. This study implied that ROS scavenging by CAT is important for S. litura survival.

  5. Acetylsalicylic acid-induced oxidative stress, cell cycle arrest, apoptosis and mitochondrial dysfunction in human hepatoma HepG2 cells.

    Science.gov (United States)

    Raza, Haider; John, Annie; Benedict, Sheela

    2011-10-01

    It is widely accepted that non-steroidal anti-inflammatory drugs (NSAIDs), including aspirin, reduce the risk of cancer. The anti-cancer and anti-inflammatory effects of NSAIDs are associated with the inhibition of prostaglandin synthesis and cyclooxygenase-2 activity. Several other mechanisms which contribute to the anti-cancer effect of these drugs in different cancer models both in vivo and in vitro are also presumed to be involved. The precise molecular mechanism, however, is still not clear. We investigated, therefore, the effects of acetylsalicylic acid (ASA, aspirin) on multiple cellular and functional targets, including mitochondrial bioenergetics, using human hepatoma HepG2 cancer cells in culture. Our results demonstrate that ASA induced G0/G1 cell cycle arrest and apoptosis in HepG2 cells. ASA increased the production of reactive oxygen species, reduced the cellular glutathione (GSH) pool and inhibited the activities of the mitochondrial respiratory enzyme complexes, NADH-ubiquinone oxidoreductase (complex I), cytochrome c oxidase (complex IV) and the mitochondrial matrix enzyme, aconitase. Apoptosis was triggered by alteration in mitochondrial permeability transition, inhibition of ATP synthesis, decreased expression of the anti-apoptotic protein Bcl-2, release of cytochrome c and activation of pro-apoptotic caspase-3 and the DNA repairing enzyme, poly (-ADP-ribose) polymerase (PARP). These findings strongly suggest that ASA-induced toxicity in human hepatoma HepG2 cells is mediated by increased metabolic and oxidative stress, accompanied by mitochondrial dysfunction which result in apoptosis.

  6. Depletion of intrinsic expression of Interleukin-8 in prostate cancer cells causes cell cycle arrest, spontaneous apoptosis and increases the efficacy of chemotherapeutic drugs

    Directory of Open Access Journals (Sweden)

    Lokeshwar Bal L

    2009-07-01

    Full Text Available Abstract Background The progression of all cancers is characterized by increased-cell proliferation and decreased-apoptosis. The androgen-independent prostate cancer (AIPC is the terminal stage of the disease. Many chemokines and cytokines are suspects to cause this increased tumor cell survival that ultimately leads to resistance to therapy and demise of the host. The AIPC cells, but not androgen-responsive cells, constitutively express abundant amount of the pro-inflammatory chemokine, Interleukin-8 (IL-8. The mechanism of IL-8 mediated survival and therapeutic resistance in AIPC cells is unclear at present. The purpose of this report is to show the pervasive role of IL-8 in malignant progression of androgen-independent prostate cancer (AIPC and to provide a potential new therapeutic avenue, using RNA interference. Results The functional consequence of IL-8 depletion in AIPC cells was investigated by RNA interference in two IL-8 secreting AIPC cell lines, PC-3 and DU145. The non-IL-8 secreting LNCaP and LAPC-4 cells served as controls. Cells were transfected with RISC-free siRNA (control or validated-pool of IL-8 siRNA. Transfection with 50 nM IL-8 siRNA caused >95% depletion of IL-8 mRNA and >92% decrease in IL-8 protein. This reduction in IL-8 led to cell cycle arrest at G1/S boundary and decreases in cell cycle-regulated proteins: Cyclin D1 and Cyclin B1 (both decreased >50% and inhibition of ERK1/2 activity by >50%. Further, the spontaneous apoptosis was increased by >43% in IL-8 depleted cells, evidenced by increases in caspase-9 activation and cleaved-PARP. IL-8 depletion caused significant decreases in anti-apoptotic proteins, BCL-2, BCL-xL due to decrease in both mRNA and post-translational stability, and increased levels of pro-apoptotic BAX and BAD proteins. More significantly, depletion of intracellular IL-8 increased the cytotoxic activity of multiple chemotherapeutic drugs. Specifically, the cytotoxicity of Docetaxel

  7. Avian reovirus nonstructural protein p17-induced G(2)/M cell cycle arrest and host cellular protein translation shutoff involve activation of p53-dependent pathways.

    Science.gov (United States)

    Chulu, Julius L C; Huang, Wei R; Wang, L; Shih, Wen L; Liu, Hung J

    2010-08-01

    The effects of avian reovirus (ARV) p17 protein on cell cycle progression and host cellular protein translation were studied. ARV infection and ARV p17 transfection resulted in the accumulation of infected and/or transfected cells in the G(2)/M phase of the cell cycle. The accumulation of cells in the G(2)/M phase was accompanied by upregulation and phosphorylation of the G(2)/M-phase proteins ATM, p53, p21(cip1/waf1), Cdc2, cyclin B1, Chk1, Chk2, and Cdc25C, suggesting that p17 induces a G(2)/M cell cycle arrest through activation of the ATM/p53/p21(cip1/waf1)/Cdc2/cyclin B1 and ATM/Chk1/Chk2/Cdc25C pathways. The G(2)/M cell cycle arrest resulted in increased virus replication. In the present study, we also provide evidence demonstrating that p17 protein is responsible for ARV-induced host cellular protein translation shutoff. Increased phosphorylation levels of the eukaryotic translation elongation factor 2 (eEF2) and initiation factor eIF2alpha and reduced phosphorylation levels of the eukaryotic translation initiation factors eIF4E, eIF4B, and eIF4G, as well as 4E-BP1 and Mnk-1 in p17-transfected cells, demonstrated that ARV p17 suppresses translation initiation factors and translation elongation factors to induce host cellular protein translation shutoff. Inhibition of mTOR by rapamycin resulted in a decrease in the levels of phosphorylated 4E-BP1, eIF4B, and eIF4G and an increase in the levels eEF2 but did not affect ARV replication, suggesting that ARV replication was not hindered by inhibition of cap-dependent translation. Taken together, our data indicate that ARV p17-induced G(2)/M arrest and host cellular translation shutoff resulted in increased ARV replication.

  8. Dendrobium candidum inhibits MCF-7 cells proliferation by inducing cell cycle arrest at G2/M phase and regulating key biomarkers

    Directory of Open Access Journals (Sweden)

    Sun J

    2015-12-01

    <0.05. The general apoptosis biomarker, Bcl-2, was significantly decreased and the Bax was significantly increased compared to the control group (P<0.05. In contrast to that in MCF-7, D. candidum does not affect cell proliferation at any concentration and any time points in normal breast epithelial cells, MCF10A cells. Conclusion: D. candidum could decrease the cell viability of MCF-7 cells by inducing cell cycle arrest at the G2/M phase and regulating the key biomarkers in breast cancer cells. Keywords: breast cancer, D. candidum, proliferation, biomarker, inhibition

  9. The role of the RACK1 ortholog Cpc2p in modulating pheromone-induced cell cycle arrest in fission yeast.

    Directory of Open Access Journals (Sweden)

    Magdalena Mos

    Full Text Available The detection and amplification of extracellular signals requires the involvement of multiple protein components. In mammalian cells the receptor of activated C kinase (RACK1 is an important scaffolding protein for signal transduction networks. Further, it also performs a critical function in regulating the cell cycle by modulating the G1/S transition. Many eukaryotic cells express RACK1 orthologs, with one example being Cpc2p in the fission yeast Schizosaccharomyces pombe. In contrast to RACK1, Cpc2p has been described to positively regulate, at the ribosomal level, cells entry into M phase. In addition, Cpc2p controls the stress response pathways through an interaction with Msa2p, and sexual development by modulating Ran1p/Pat1p. Here we describe investigations into the role, which Cpc2p performs in controlling the G protein-mediated mating response pathway. Despite structural similarity to Gβ-like subunits, Cpc2p appears not to function at the G protein level. However, upon pheromone stimulation, cells overexpressing Cpc2p display substantial cell morphology defects, disorientation of septum formation and a significantly protracted G1 arrest. Cpc2p has the potential to function at multiple positions within the pheromone response pathway. We provide a mechanistic interpretation of this novel data by linking Cpc2p function, during the mating response, with its previous described interactions with Ran1p/Pat1p. We suggest that overexpressing Cpc2p prolongs the stimulated state of pheromone-induced cells by increasing ste11 gene expression. These data indicate that Cpc2p regulates the pheromone-induced cell cycle arrest in fission yeast by delaying cells entry into S phase.

  10. Short-term inhibition of TERT induces telomere length-independent cell cycle arrest and apoptotic response in EBV-immortalized and transformed B cells

    Science.gov (United States)

    Celeghin, Andrea; Giunco, Silvia; Freguja, Riccardo; Zangrossi, Manuela; Nalio, Silvia; Dolcetti, Riccardo; De Rossi, Anita

    2016-01-01

    Besides its canonical role in stabilizing telomeres, telomerase reverse transcriptase (TERT) may promote tumorigenesis through extra-telomeric functions. The possible therapeutic effects of BIBR1532 (BIBR), a powerful TERT inhibitor, have been evaluated in different cellular backgrounds, but no data are currently available regarding Epstein–Barr virus (EBV)-driven B-cell malignancies. Our aim was to characterize the biological effects of TERT inhibition by BIBR on EBV-immortalized lymphoblastoid cell lines (LCLs) and fully transformed Burkitt's lymphoma (BL) cell lines. We found that BIBR selectively inhibits telomerase activity in TERT-positive 4134/Late and 4134/TERT+ LCLs and EBV-negative BL41 and EBV-positive BL41/B95.8 BL cell lines. TERT inhibition led to decreased cell proliferation, accumulation of cells in the S-phase and ultimately to increased apoptosis, compared with mock-treated control cells. All these effects occurred within 72 h and were not observed in BIBR-treated TERT-negative 4134/TERT- and U2OS cells. The cell cycle arrest and apoptosis, consequent upon short-term TERT inhibition, were associated with and likely dependent on the activation of the DNA damage response (DDR), highlighted by the increased levels of γH2AX and activation of ATM and ATR pathways. Analyses of the mean and range of telomere lengths and telomere dysfunction-induced foci indicated that DDR after short-term TERT inhibition was not related to telomere dysfunction, thus suggesting that TERT, besides stabilizing telomere, may protect DNA via telomere-independent mechanisms. Notably, TERT-positive LCLs treated with BIBR in combination with fludarabine or cyclophosphamide showed a significant increase in the number of apoptotic cells with respect to those treated with chemotherapeutic agents alone. In conclusion, TERT inhibition impairs cell cycle progression and enhances the pro-apoptotic effects of chemotherapeutic agents in TERT-positive cells. These results support new

  11. Hydroxylation of multi-walled carbon nanotubes: Enhanced biocompatibility through reduction of oxidative stress initiated cell membrane damage, cell cycle arrestment and extrinsic apoptotic pathway.

    Science.gov (United States)

    Liu, Zhenbao; Liu, Yanfei; Peng, Dongming

    2016-10-01

    Modification of CNTs with hydroxyl group promotes their applications in biomedical area. However, the impact of hydroxylation on their biocompatibility is far from being completely understood. In this study, we carried out a comprehensive evaluation of hydroxylated multi-walled carbon nanotubes (MWCNTs-OH) on the human normal liver L02 cell line, and compared it with that of pristine multi-walled carbon nanotubes (p-MWCNTs). Results demonstrated that compared with p-MWCNTs, MWCNTs-OH induced significantly lower oxidative stress as indicated by the level of intracellular antioxidant glutathione (GSH), subsequently lead to less cell membrane damage as demonstrated by lactate dehydrogenase (LDH) leakage assay, and showed slightly decreased arrestment of cell cycle distribution at G0/G1. More interestingly, MWCNTs-OH exhibited significantly lower tendency to activate caspase-8, a key molecule involved in the extrinsic apoptotic pathway. All these in vitro results demonstrated that hydroxylation of MWCNTs enhanced their biocompatibility compare with p-MWCNTs.

  12. Non-homologous end joining dependency of {gamma}-irradiation-induced adaptive frameshift mutation formation in cell cycle-arrested yeast cells

    Energy Technology Data Exchange (ETDEWEB)

    Heidenreich, Erich [Institute of Cancer Research, Division of Molecular Genetics, Medical University of Vienna, Borschkegasse 8a, A-1090 Vienna (Austria)]. E-mail: erich.heidenreich@meduniwien.ac.at; Eisler, Herfried [Institute of Cancer Research, Division of Molecular Genetics, Medical University of Vienna, Borschkegasse 8a, A-1090 Vienna (Austria)

    2004-11-22

    There is a strong selective pressure favoring adaptive mutations which relieve proliferation-limiting adverse living conditions. Due to their importance for evolution and pathogenesis, we are interested in the mechanisms responsible for the formation of such adaptive, gain-of-fitness mutations in stationary-phase cells. During previous studies on the occurrence of spontaneous reversions of an auxotrophy-causing frameshift allele in the yeast Saccharomyces cerevisiae, we noticed that about 50% of the adaptive reversions depended on a functional non-homologous end joining (NHEJ) pathway of DNA double-strand break (DSB) repair. Here, we show that the occasional NHEJ component Pol4, which is the yeast ortholog of mammalian DNA polymerase lambda, is not required for adaptive mutagenesis. An artificially imposed excess of DSBs by {gamma}-irradiation resulted in a dramatic increase in the incidence of adaptive, cell cycle arrest-releasing frameshift reversions. By the use of DNA ligase IV-deficient strains we detected that the majority of the {gamma}-induced adaptive mutations were also dependent on a functional NHEJ pathway. This suggests that the same mutagenic NHEJ mechanism acts on spontaneously arising as well as on ionizing radiation-induced DSBs. Inaccuracy of the NHEJ repair pathway may extensively contribute to the incidence of frameshift mutations in resting (non-dividing) eukaryotic cells, and thus act as a driving force in tumor development.

  13. G protein-coupled receptor 30 ligand G-1 increases aryl hydrocarbon receptor signalling by inhibition of tubulin assembly and cell cycle arrest in human MCF-7 cells.

    Science.gov (United States)

    Tarnow, Patrick; Tralau, Tewes; Luch, Andreas

    2016-08-01

    Regulatory crosstalk between the aryl hydrocarbon receptor (AHR) and oestrogen receptor α (ERα) is well established. Apart from the nuclear receptors ERα and ERβ, oestrogen signalling further involves an unrelated G protein-coupled receptor termed GPR30. In order to investigate potential regulatory crosstalk, this study investigated the influence of G-1 as one of the few GPR30-specific ligands on the AHR regulon in MCF-7 cells. As a well-characterised model system, these human mammary carcinoma cells co-express all three receptors (AHR, ERα and GPR30) and are thus ideally suited to study corresponding regulatory pathway interactions on transcript level. Indeed, treatment with micromolar concentrations of the GPR30-specific agonist G-1 resulted in up-regulation of AHR as well as the transcripts for cytochromes P450 1A1 and 1B1, two well-known targets of the AHR regulon. While this was partly attributable to G-1-mediated inhibition of tubulin assembly and subsequent cell cycle arrest in the G2/M phase, the effects nevertheless required functional AHR. However, G-1-induced up-regulation of CYP 1A1 was not mediated by GPR30, as G15 antagonist treatment as well as a knockdown of GPR30 and AHR failed to inhibit this effect.

  14. Transforming growth factor-β1 induces cell cycle arrest by activating atypical cyclin-dependent kinase 5 through up-regulation of Smad3-dependent p35 expression in human MCF10A mammary epithelial cells.

    Science.gov (United States)

    Park, Seong Ji; Yang, Sun Woo; Kim, Byung-Chul

    2016-04-01

    Cyclin-dependent kinases (Cdks) play important roles in control of cell division. Cdk5 is an atypical member of Cdk family with non-cyclin-like regulatory subunit, p35, but its role in cell cycle progression is still unclear. In the present study, we investigated the role of Cdk5/p35 on transforming growth factor-β1 (TGF-β1)-induced cell cycle arrest. In human MCF10A mammary epithelial cells, TGF-β1 induced cell cycle arrest at G1 phase and increased p27KIP1 expression. Interestingly, pretreatment with roscovitine, an inhibitor of Cdk5, or transfection with small interfering (si) RNAs specific to Cdk5 and p35 significantly attenuated the TGF-β1-induced p27KIP1 expression and cell cycle arrest. TGF-β1 increased Cdk5 activity via up-regulation of p35 gene at transcriptional level, and these effects were abolished by transfection with Smad3 siRNA or infection of adenovirus carrying Smad3 mutant at the C-tail (3SA). Chromatin immunoprecipitation assay further revealed that wild type Smad3, but not mutant Smad3 (3SA), binds to the region of the p35 promoter region (-1000--755) in a TGF-β1-dependent manner. These results for the first time demonstrate a role of Cdk5/p35 in the regulation of cell cycle progression modulated by TGF-β1.

  15. Cell cycle arrest and apoptosis induced by 1α,25(OH)2D3 and TX 527 in Kaposi sarcoma is VDR dependent.

    Science.gov (United States)

    González-Pardo, Verónica; Suares, Alejandra; Verstuyf, Annemieke; De Clercq, Pierre; Boland, Ricardo; de Boland, Ana Russo

    2014-10-01

    We have previously shown that 1α,25(OH)2-Vitamin D3 [1α,25(OH)2D3] and its less calcemic analog TX 527 inhibit the proliferation of endothelial cells transformed by the viral G protein-coupled receptor associated to Kaposi sarcoma (vGPCR) and this could be partially explained by the inhibition of the NF-κB pathway. In this work, we further explored the mechanism of action of both vitamin D compounds in Kaposi sarcoma. We investigated whether the cell cycle arrest and subsequent apoptosis of endothelial cells (SVEC) and SVEC transformed by vGPCR (SVEC-vGPCR) elicited by 1α,25(OH)2D3 and TX 527 were mediated by the vitamin D receptor (VDR). Cell cycle analysis of SVEC and SVEC-vGPCR treated with 1α,25(OH)2D3 (10nM, 48h) revealed that 1α,25(OH)2D3 increased the percentage of cells in the G0/G1 phase and diminished the percentage of cells in the S phase of the cell cycle. Moreover, the number of cells in the S phase was higher in SVEC-vGPCR than in SVEC due to vGPCR expression. TX 527 exerted similar effects on growth arrest in SVEC-vGPCR cells. The cell cycle changes were suppressed when the expression of the VDR was blocked by a stable transfection of shRNA against VDR. Annexin V-PI staining demonstrated apoptosis in both SVEC and SVEC-vGPCR after 1α,25(OH)2D3 and TX 527 treatment (10nM, 24h). Cleavage of caspase-3 detected by Western blot analysis was increased to a greater extent in SVEC than in SVEC-vGPCR cells, and this effect was also blocked in VDR knockdown cells. Altogether, these results suggest that 1α,25(OH)2D3 and TX 527 inhibit the proliferation of SVEC and SVEC-vGPCR and induce apoptosis by a mechanism that involves the VDR.

  16. [10]-Gingerol, a major phenolic constituent of ginger root, induces cell cycle arrest and apoptosis in triple-negative breast cancer cells.

    Science.gov (United States)

    Bernard, Megan M; McConnery, Jason R; Hoskin, David W

    2017-03-16

    The ginger rhizome is rich in bioactive compounds, including [6]-gingerol, [8]-gingerol, and [10]-gingerol; however, to date, most research on the anti-cancer activities of gingerols have focused on [6]-gingerol. In this study, we compared [10]-gingerol with [8]-gingerol and [6]-gingerol in terms of their ability to inhibit the growth of human and mouse mammary carcinoma cells. A colorimetric assay based on the enzymatic reduction of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide revealed that [10]-gingerol was more potent than [6]-gingerol and at least as potent as [8]-gingerol for the inhibition of triple-negative human (MDA-MB-231, MDA-MB-468) and mouse (4T1, E0771) mammary carcinoma cell growth. Further investigation of [10]-gingerol showed that it suppressed the growth of estrogen receptor-bearing (MCF-7, T47D) and HER2-overexpressing (SKBR3) breast cancer cells. The inhibitory effect of [10]-gingerol on the growth of MDA-MB-231 cells was associated with a reduction in the number of rounds of cell division and evidence of S phase-cell cycle arrest, as well as induction of apoptosis due to mitochondrial outer membrane permeabilization and the release of proapoptotic mitochondrial cytochrome c and SMAC/DIABLO into the cytoplasm. Surprisingly, killing of MDA-MB-231 cells by [10]-gingerol was not affected by a pan-caspase inhibitor (zVAD-fmk) or an anti-oxidant (N-acetylcysteine), suggesting that the cytotoxic effect of [10]-gingerol did not require caspase activation or the accumulation of reactive oxygen species. These findings suggest that further investigation of [10]-gingerol is warranted for its possible use in the treatment of breast cancer.

  17. The ubiquitin peptidase UCHL1 induces G0/G1 cell cycle arrest and apoptosis through stabilizing p53 and is frequently silenced in breast cancer.

    Directory of Open Access Journals (Sweden)

    Tingxiu Xiang

    Full Text Available BACKGROUND: Breast cancer (BrCa is a complex disease driven by aberrant gene alterations and environmental factors. Recent studies reveal that abnormal epigenetic gene regulation also plays an important role in its pathogenesis. Ubiquitin carboxyl- terminal esterase L1 (UCHL1 is a tumor suppressor silenced by promoter methylation in multiple cancers, but its role and alterations in breast tumorigenesis remain unclear. METHODOLOGY/PRINCIPAL FINDINGS: We found that UCHL1 was frequently downregulated or silenced in breast cancer cell lines and tumor tissues, but readily expressed in normal breast tissues and mammary epithelial cells. Promoter methylation of UCHL1 was detected in 9 of 10 breast cancer cell lines (90% and 53 of 66 (80% primary tumors, but rarely in normal breast tissues, which was statistically correlated with advanced clinical stage and progesterone receptor status. Pharmacologic demethylation reactivated UCHL1 expression along with concomitant promoter demethylation. Ectopic expression of UCHL1 significantly suppressed the colony formation and proliferation of breast tumor cells, through inducing G0/G1 cell cycle arrest and apoptosis. Subcellular localization study showed that UCHL1 increased cytoplasmic abundance of p53. We further found that UCHL1 induced p53 accumulation and reduced MDM2 protein level, and subsequently upregulated the expression of p21, as well as cleavage of caspase3 and PARP, but not in catalytic mutant UCHL1 C90S-expressed cells. CONCLUSIONS/SIGNIFICANCE: UCHL1 exerts its tumor suppressive functions by inducing G0/G1cell cycle arrest and apoptosis in breast tumorigenesis, requiring its deubiquitinase activity. Its frequent silencing by promoter CpG methylation may serve as a potential tumor marker for breast cancer.

  18. A platinum(II) complex of liriodenine from traditional Chinese medicine (TCM): Cell cycle arrest, cell apoptosis induction and telomerase inhibition activity via G-quadruplex DNA stabilization.

    Science.gov (United States)

    Li, Yu-Lan; Qin, Qi-Pin; Liu, Yan-Cheng; Chen, Zhen-Feng; Liang, Hong

    2014-08-01

    Liriodenine (L), an antitumor active ingredient from the traditional Chinese medicine (TCM), Zanthoxylum nitidum, afforded a platinum(II) complex (1) of L, cis-[PtCl2(L)(DMSO)], which previously reported for its in vitro antitumor activity and intercalative binding with DNA. In this study, complex 1 was further discussed for its antitumor mechanism and structure-activity relationship, comparing with L and cisplatin. Towards the most sensitive BEL-7404 human hepatoma cells, complex 1 significantly induced cell cycle arrest at both G2/M phase and S phase. It suggests that double helix DNA is not the simplex intracellular target for 1. On the other hand, the BEL-7404 cells incubated with 1 and stained by Hoechst 33258 and AO/EB showed typical cell apoptosis in dose-dependent manner. The BEL-7404 cells incubated with 1 and stained by JC-1 were also characteristic for cell apoptosis on the loss of mitochondrial membrane potential. Furthermore, the G-quadruplex DNA binding property of complex 1 was also investigated by spectroscopic analyses, fluorescent indicator displacement (FID) assay and fluorescence resonance energy transfer (FRET) assay. The results indicated that 1 stabilized the human telomeric G4-HTG21 DNA better than L. The telomerase inhibition ratio of 1 ((62.50±0.03)%), which was examined by telomerase polymerase chain reaction-enzyme-linked immunosorbent assay (PCR-ELISA), was much higher than L ((21.77±0.01)%). It can be ascribed to the better G4-HTG21 DNA stabilization of 1 than L. The results suggested that the nuclei, mitochondria and telomerase via G-quadruplex DNA stabilization all should be key targets for the antitumor mechanism of 1, in which the central platinum(II) played a key role.

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

    Energy Technology Data Exchange (ETDEWEB)

    Han, Yuanyuan; He, Haiyun [State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, West China Medical School, Sichuan University, Chengdu 610041 (China); Peng, Feng [Department of Thoracic Oncology of the Cancer Center and State Key Laboratory of Biotherapy, West China Hospital, West China Medical School, Sichuan University, Chengdu 610041 (China); Liu, Jiyan; Dai, Xiaoyun; Lin, Hongjun; Xu, Youzhi; Zhou, Tian; Mao, Yongqiu; Xie, Gang; Yang, Shengyong; Yu, Luoting; Yang, Li [State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, West China Medical School, Sichuan University, Chengdu 610041 (China); Zhao, Yinglan, E-mail: alancenxb@sina.com [State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, West China Medical School, Sichuan University, Chengdu 610041 (China)

    2012-05-18

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

  20. Suppressed expression of non-DSB repair genes inhibits gamma-radiation-induced cytogenetic repair and cell cycle arrest.

    Science.gov (United States)

    Zhang, Ye; Rohde, Larry H; Emami, Kamal; Hammond, Dianne; Casey, Rachael; Mehta, Satish K; Jeevarajan, Antony S; Pierson, Duane L; Wu, Honglu

    2008-11-01

    Changes of gene expression profile are one of the most important biological responses in living cells after ionizing radiation (IR) exposure. Although some studies have shown that genes up-regulated by IR may play important roles in DNA damage repair, the relationship between the regulation of gene expression by IR, particularly genes not known for their roles in double-strand break (DSB) repair, and its impact on cytogenetic responses has not been well studied. The purpose of this study is to identify new roles of IR inducible genes in regulating DSB repair and cell cycle progression. In this study, the expression of 25 genes selected on the basis of their transcriptional changes in response to IR was individually knocked down by small interfering RNA in human fibroblast cells. Frequency of micronuclei (MN) formation and chromosome aberrations were measured to determine efficiency of cytogenetic repair, especially DSB repair. In response to IR, the formation of MN was significantly increased by suppressed expression of five genes: Ku70 (DSB repair pathway), XPA (nucleotide excision repair pathway), RPA1 (mismatch repair pathway), RAD17 and RBBP8 (cell cycle control). Knocked-down expression of four genes (MRE11A, RAD51 in the DSB pathway, SESN1, and SUMO1) significantly inhibited cell cycle progression, possibly because of severe impairment of DNA damage repair. Moreover, decreased XPA, p21, or MLH1 expression resulted in both significantly enhanced cell cycle progression and increased yields of chromosome aberrations, indicating that these gene products modulate both cell cycle control and DNA damage repair. Nine of these eleven genes, whose knock-down expression affected cytogenetic repair, were up-regulated in cells exposed to gamma radiation, suggesting that genes transcriptionally modulated by IR were critical to regulate IR-induced biological consequences. Furthermore, eight non-DBS repair genes showed involvement in regulating DSB repair, indicating that

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

    OpenAIRE

    Wang, Hualin; ZHANG Jing; Sit, Wai-Hung; Lee, Chung-Yung Jetty; Wan, Jennifer Man-Fan

    2014-01-01

    Background Cordyceps cicadae is a medicinal fungus that is often used for treating cancer. However, the anticancer mechanisms of C. cicadae are largely unknown. This study aims to investigate the anticancer mechanisms of C. cicadae against hepatocellular carcinoma cells in vitro using a proteomic approach. Methods Human hepatocellular carcinoma MHCC97H cells were treated with a water extract of C. cicadae (0, 100, 250, 500, and 1000 μg/mL) for 48 h and harvested for cell viability assays. The...

  2. 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.

  3. Sparstolonin B, a novel plant derived compound, arrests cell cycle and induces apoptosis in N-myc amplified and N-myc nonamplified neuroblastoma cells.

    Directory of Open Access Journals (Sweden)

    Ambrish Kumar

    Full Text Available Neuroblastoma is one of the most common solid tumors and accounts for ∼ 15% of all the cancer related deaths in the children. Despite the standard therapy for advanced disease including chemotherapy, surgery, and radiation, the mortality rate remains high for these patients. Hence, novel therapeutic agents are desperately needed. Here we examined the anticancer activity of a novel plant-derived compound, sparstolonin B (SsnB; 8,5'-dihydroxy-4-phenyl-5,2'-oxidoisocoumarin using neuroblastoma cell lines of different genetics. SsnB was recently isolated from an aquatic Chinese herb, Sparganium stoloniferum, and tubers of this herb have been used in traditional Chinese medicine for the treatment of several inflammatory diseases and cancers. Our cell viability and morphological analysis indicated that SsnB at 10 µM concentration significantly inhibited the growth of both N-myc amplified (SK-N-BE(2, NGP, and IMR-32 cells and N-myc nonamplified (SH-SY5Y and SKNF-1 cells neuroblastoma cells. The flow cytometric analyses suggested that SsnB arrests the cell cycle progression at G2-M phase in all neuroblastoma cell lines tested. Exposure of SsnB inhibited the compact spheroid formation and reduced the tumorigenicity of SH-SY5Y cells and SK-N-BE(2 cells in in vitro 3-D cell culture assays (anchorage-independent colony formation assay and hanging drop assay. SsnB lowers the cellular level of glutathione (GSH, increases generation of reactive oxygen species and activates the cleavage of caspase-3 whereas co-incubation of a GSH precursor, N-acetylcysteine, along with SsnB attenuates the inhibitory effects of SsnB and increases the neuroblastoma cell viability. Our results for the first time demonstrate that SsnB possesses anticancer activity indicating that SsnB-induced reactive oxygen species generation promotes apoptotic cell death in neuroblastoma cells of different genetic background. Thus these data suggest that SsnB can be a promising drug candidate

  4. Anti-cancer effect of Cordyceps militaris in human colorectal carcinoma RKO cells via cell cycle arrest and mitochondrial apoptosis

    OpenAIRE

    Lee, Hwan Hee; Lee, Seulki; Lee, Kanghyo; Shin, Yu Su; Kang, Hyojeung; Cho, Hyosun

    2015-01-01

    Background Cordyceps militaris has been used as a traditional medicine in Asian countries for a long time. Different types of Cordyceps extract were reported to have various pharmacological activities including an anti-cancer effect. We investigated the inhibitory effect of Cordyceps militaris ethanol extract on a human colorectal cancer-derived cell line, RKO. Methods RKO cells were treated with various concentrations of nucleosides-enriched ethanol extract of Cordyceps militaris for 48 h an...

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

    OpenAIRE

    Wai Wing So; Wai Nam Liu; Kwok Nam Leung

    2015-01-01

    Omega-3 (n-3) fatty acids are dietary long-chain fatty acids with an array of health benefits. Previous research has demonstrated the growth-inhibitory effect of n-3 fatty acids on different cancer cell lines in vitro, yet their anti-tumor effects and underlying action mechanisms on human neuroblastoma LA-N-1 cells have not yet been reported. In this study, we showed that docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) exhibited time- and concentration-dependent anti-proliferative ...

  6. Cdk5 phosphorylates non-genotoxically overexpressed p53 following inhibition of PP2A to induce cell cycle arrest/apoptosis and inhibits tumor progression

    Directory of Open Access Journals (Sweden)

    Kumari Ratna

    2010-07-01

    Full Text Available Abstract Background p53 is the most studied tumor suppressor and its overexpression may or may not cause cell death depending upon the genetic background of the cells. p53 is degraded by human papillomavirus (HPV E6 protein in cervical carcinoma. Several stress activated kinases are known to phosphorylate p53 and, among them cyclin dependent kinase 5 (Cdk5 is one of the kinase studied in neuronal cell system. Recently, the involvement of Cdk5 in phosphorylating p53 has been shown in certain cancer types. Phosphorylation at specific serine residues in p53 is essential for it to cause cell growth inhibition. Activation of p53 under non stress conditions is poorly understood. Therefore, the activation of p53 and detection of upstream kinases that phosphorylate non-genotoxically overexpressed p53 will be of therapeutic importance for cancer treatment. Results To determine the non-genotoxic effect of p53; Tet-On system was utilized and p53 inducible HPV-positive HeLa cells were developed. p53 overexpression in HPV-positive cells did not induce cell cycle arrest or apoptosis. However, we demonstrate that overexpressed p53 can be activated to upregulate p21 and Bax which causes G2 arrest and apoptosis, by inhibiting protein phosphatase 2A. Additionally, we report that the upstream kinase cyclin dependent kinase 5 interacts with p53 to phosphorylate it at Serine20 and Serine46 residues thereby promoting its recruitment on p21 and bax promoters. Upregulation and translocation of Bax causes apoptosis through intrinsic mitochondrial pathway. Interestingly, overexpressed activated p53 specifically inhibits cell-growth and causes regression in vivo tumor growth as well. Conclusion Present study details the mechanism of activation of p53 and puts forth the possibility of p53 gene therapy to work in HPV positive cervical carcinoma.

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

    Science.gov (United States)

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

  8. Butyrate Induced Cell Cycle Arrest in Bovine Cells through Targeting Gene Expression relevance to DNA Replication Apparatus

    Science.gov (United States)

    Using both real-time RT-PCR and Western blot analysis in bovine kidney epithelial cells, we systematically investigated the gene expression relevance to DNA replication apparatus targeted by butyrate. The real-time PCR and Western blot data generally confirmed the microarray analysis. From the quan...

  9. Notch1 induces cell cycle arrest and apoptosis in human cervical cancer cells : involvement of nuclear factor kappa B inhibition

    NARCIS (Netherlands)

    Yao, J.; Duan, L.; Fan, M.; Yuan, J.; Wu, X.

    2007-01-01

    Notch signaling can serve as a tumor suppressor or tumor promoter in the same kind of cancer, such as human papillomavirus-positive cervical cancer cells. However, the exact mechanisms remain poorly characterized. Our studies demonstrated that constitutively overexpressed active Notch1 via stable tr

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

    Directory of Open Access Journals (Sweden)

    Wang F

    2015-01-01

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

  11. Non-aqueous extracts of Curcuma mangga rhizomes induced cell death in human colorectal adenocarcinoma cell line (HT29) via induction of apoptosis and cell cycle arrest at G0/G1 phase

    Institute of Scientific and Technical Information of China (English)

    Gin Wah Hong; Sok Lai Hong; Guan Serm Lee; Hashim Yaacob; Sri Nurestri Abd Malek

    2016-01-01

    Objective: To investigate the cytotoxic activity of the hexane and ethyl acetate extracts of Curcuma mangga rhizomes against human colorectal adenocarcinoma cell lines (HT29). Methods: The cytotoxic activity of the hexane and ethyl acetate extracts of Curcuma mangga rhizomes against human colorectal adenocarcinoma cell lines (HT29) was determined by using the SRB assay. Results: The ethyl acetate extract showed a higher cytotoxic effect compared to the hexane extract. Morphological changes of the HT29 cells such as cell shrinkage, membrane blebbling and formation of apoptotic bodies while changes in nuclear morphology like chromatin condensation and nuclear fragmentation were observed. Further evidence of apoptosis in HT29 cells was further supported by the externalization of phosphatidylserine which indicate early sign of apoptosis. Conclusions: The early sign of apoptosis is consistent with the cell cycle arrest at the G0/G1 checkpoint which suggests that the changes on the cell cycle lead to the induction of apoptosis in HT29.

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

    Science.gov (United States)

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

    2016-03-01

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

  13. Fe3O4 nanoparticle loaded paclitaxel induce multiple myeloma apoptosis by cell cycle arrest and increase cleavage of caspases in vitro

    Science.gov (United States)

    Yang, Cuiping; He, Xiangfeng; Chen, Junsong; Chen, Dengyu; Liu, Yunjing; Xiong, Fei; Shi, Fangfang; Dou, Jun; Gu, Ning

    2013-08-01

    Multiple myeloma (MM) still remains an incurable disease in spite of extending the patient survival by new therapies. The hypothesis of cancer stem cells (CSCs) states that although chemotherapy kills most tumor cells, it is believed to leave a reservoir of CSCs that allows the tumor cell propagation. The objective of this research was to evaluate the therapeutic effect of new paclitaxel-Fe3O4 nanoparticles (PTX-NPs) with an average size range of 7.17 ± 1.31 nm on MM CSCs in vitro. The characteristics of CD138-CD34- cells, isolated from human MM RPMI 8226 and NCI-H929 cell lines by the magnetic associated cell sorting method, were identified by the assays of colony formation, cell proliferation, drug resistance, cell migration, and tumorigenicity in non-obese diabetic/severe combined immunodeficiency (NOD/SCID) mice, respectively. Inhibitory effects of PTX-NPs on CD138-CD34- cells were evaluated by a variety of assays in vitro. The results showed that the CD138-CD34- cells were capable of forming colonies, exhibited high proliferative and migratory ability, possessed a strong drug resistance, and had powerful tumorigenicity in NOD/SCID mice compared to non-CD138-CD34- cells. PTX-NPs significantly inhibited CD138- CD34- cell viability and invasive ability, and resulted in G0/G1 cell cycle arrest and apoptosis compared with PTX alone. We concluded that the CD138-CD34- phenotype cells might be CSCs in RPMI 8226 and NCI-H929 cell lines. PTX-NPs had an obvious inhibitory effect on MM CD138-CD34- CSCs. The findings may provide a guideline for PTX-NPs' treatment of MM CSCs in preclinical investigation.

  14. Fe{sub 3}O{sub 4} nanoparticle loaded paclitaxel induce multiple myeloma apoptosis by cell cycle arrest and increase cleavage of caspases in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Cuiping [Medical School, Southeast University, Department of Pathogenic Biology and Immunology (China); He, Xiangfeng [Affiliated Tumor Hospital of Nantong University, Department of Medical Oncology (China); Chen, Junsong; Chen, Dengyu; Liu, Yunjing [Medical School, Southeast University, Department of Pathogenic Biology and Immunology (China); Xiong, Fei [Southeast University, School of Biological Science and Medical Engineering (China); Shi, Fangfang [Zhongda Hospital, Southeast University, Department of Oncology (China); Dou, Jun, E-mail: njdoujun@yahoo.com.cn [Medical School, Southeast University, Department of Pathogenic Biology and Immunology (China); Gu, Ning, E-mail: guning@seu.edu.cn [Southeast University, School of Biological Science and Medical Engineering (China)

    2013-08-15

    Multiple myeloma (MM) still remains an incurable disease in spite of extending the patient survival by new therapies. The hypothesis of cancer stem cells (CSCs) states that although chemotherapy kills most tumor cells, it is believed to leave a reservoir of CSCs that allows the tumor cell propagation. The objective of this research was to evaluate the therapeutic effect of new paclitaxel-Fe{sub 3}O{sub 4} nanoparticles (PTX-NPs) with an average size range of 7.17 {+-} 1.31 nm on MM CSCs in vitro. The characteristics of CD138{sup -}CD34{sup -} cells, isolated from human MM RPMI 8226 and NCI-H929 cell lines by the magnetic associated cell sorting method, were identified by the assays of colony formation, cell proliferation, drug resistance, cell migration, and tumorigenicity in non-obese diabetic/severe combined immunodeficiency (NOD/SCID) mice, respectively. Inhibitory effects of PTX-NPs on CD138{sup -}CD34{sup -} cells were evaluated by a variety of assays in vitro. The results showed that the CD138{sup -}CD34{sup -} cells were capable of forming colonies, exhibited high proliferative and migratory ability, possessed a strong drug resistance, and had powerful tumorigenicity in NOD/SCID mice compared to non-CD138{sup -}CD34{sup -} cells. PTX-NPs significantly inhibited CD138{sup -} CD34{sup -} cell viability and invasive ability, and resulted in G0/G1 cell cycle arrest and apoptosis compared with PTX alone. We concluded that the CD138{sup -}CD34{sup -} phenotype cells might be CSCs in RPMI 8226 and NCI-H929 cell lines. PTX-NPs had an obvious inhibitory effect on MM CD138{sup -}CD34{sup -} CSCs. The findings may provide a guideline for PTX-NPs' treatment of MM CSCs in preclinical investigation.

  15. Pathological Impairment, Cell Cycle Arrest and Apoptosis of Thymus and Bursa of Fabricius Induced by Aflatoxin-Contaminated Corn in Broilers

    Science.gov (United States)

    Peng, Xi; Bai, Shiping; Ding, Xuemei; Zhang, Keying

    2017-01-01

    This study aimed to evaluate the comparative effects of aflatoxin-contaminated corn on the thymus and bursa of Fabricius (BF) in chickens by detecting histopathological lesions, cell cycle phase distribution and apoptosis. A total of 900 COBB500 male broilers were randomly allocated into five groups. The experiment lasted for six weeks and the five dietary treatments consisted of uncontaminated corn (control), 25% contaminated corn, 50% contaminated corn, 75% contaminated corn and 100% contaminated corn groups. The gross changes showed the decreased size of the thymus and BF, as well as the pale color of the BF in the broilers after aflatoxin contaminated diet exposure. There were more nuclear debris in the thymus and BF of birds in the 50%, 75%, and 100% contaminated corn groups, but the pathological impairments of the BF were more obvious than those of the thymus, which showed as more obvious lymphocyte depletion and the proliferation of reticulocytes and fibroblasts. At 21 days of age, the percentage of thymocytes and BF cells in the G2M phase was increased in a dose-dependent manner in the four AFB-contaminated corn groups. However, at 42 days of age, dietary AFB1 induced cell cycle perturbation at the G0G1 phase in thymocytes, but at the G2M phase in BF cells. The increased percentage of apoptotic cells in the thymus and BF were similarly observed in the AFB groups. According to these results, the severity of histopathological lesions may be correlated with the different sensitivity of the two central immune organs when exposed to AFB; different arrested cell cycle phases suggest that different mechanisms may be involved in the lesions of the thymus and BF, which need to be further researched.

  16. 6-Nitro-2-(3-hydroxypropyl-1H-benz[de]isoquinoline-1,3-dione, a potent antitumor agent, induces cell cycle arrest and apoptosis

    Directory of Open Access Journals (Sweden)

    Singh Shashank K

    2010-12-01

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

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

    Science.gov (United States)

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

    2017-01-01

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

  18. Angiogenesis inhibition and cell cycle arrest induced by treatment with Pseudolarix acid B alone or combined with 5-fluorouracil

    Institute of Scientific and Technical Information of China (English)

    Jingtao Liu; Wei Guo; Bo Xu; Fuxiang Ran; Mingming Chu; Hongzheng Fu; Jingrong Cui

    2012-01-01

    Angiogenesis inhibitors combined with chemotherapeutic drugs have significant efficacy in the treatment of a variety of cancers.Pseudolarix acid B (PAB) is a traditional pregnancy-terminating agent,which has previously been shown to reduce tumor growth and angiogenesis.In this study,we used the high content screening assay to examine the effects of PAB on human umbilical vein endothelial cells (HUVECs).Two hepatocarcinoma 22-transplanted mouse models were used to determine PAB efficacy in combination with 5-fluorouracil (5-Fu).Our results suggested that PAB (0.156-1.250 μM) inhibited HUVECs motility in a concentration-dependent manner without obvious cytotoxicity in vitro.In vivo,PAB (25 mg/kg/day) promoted the anti-tumor efficacy of 5-Fu (5 mg/kg/2 days) in combination therapy,resulting in significantly higher tumor inhibition rates,lower microvessel density values,and prolonged survival times.It was also demonstrated that PAB acted by blocking the cell cycle at both the G1/S boundary and M phase,down-regulation of vascular endothelial growth factor,hypoxia-inducible factor 1α and cyclin E expression,and up-regulation of cdc2 expression.These observations provide the first evidence that PAB in combination with 5-Fu may be useful in cancer treatment.

  19. A clerodane diterpene inhibit adipogenesis by cell cycle arrest and ameliorate obesity in C57BL/6 mice.

    Science.gov (United States)

    Beg, Muheeb; Shankar, Kripa; Varshney, Salil; Rajan, Sujith; Singh, Suriya Pratap; Jagdale, Pankaj; Puri, Anju; Chaudhari, Bhushan P; Sashidhara, Koneni V; Gaikwad, Anil Nilkanth

    2015-01-01

    A clerodane diterpene, 16α-Hydroxycleroda-3, 13 (14) Z-dien-15, 16-olide (compound 1) isolated from Polyalthia longifolia had previously been reported as a new structural class of HMG-CoA reductase inhibitor apart from statins. Statins are known to be anti-adipogenic in nature. The distant structural similarity between compound 1 and lovastatin (polyketide class of compound) prompted us to investigate effects of diterpene compound 1 on adipogenesis and thereby obesity. High content microscopy proved diterpene compound 1 exhibits better anti-adipogenic activity and less toxicity in differentiating adipocytes. Moreover, it reduced expression levels of PPARγ, C/EBPα and GLUT4 during differentiation in a time and concentration dependent manner. Diterpene compound 1 during early differentiation reduced MDI induced-Akt/mTOR phosphorylation and expression of cell cycle proteins, and thereby halted mitotic clonal expansion, the decisive factor in early adipogenesis. Further, its anti-adipogenic activity was validated in murine mesenchymal cell-line C3H10T1/2 and human mesenchymal stem cell models of adipogenic differentiation. When compound 1 was administered along with HFD, for another 8 weeks in 2 month HFD fed overweight mice (with BMI > 30 and impaired glucose tolerance), it attenuated weight gain and epididymal fat accumulation. It improved body glucose tolerance, reduced HFD induced increase in total cholesterol and leptin/adiponectin ratio. All these effects were comparable with standard anti-obesity drug Orlistat with added edge of potently decreasing circulating triglyceride levels comparable with normal chow fed group. Histological analysis shows that compound 1 inhibit adipocyte hypertrophy and decreased steatosis in hepatocytes. Both in vivo and in vitro results demonstrate a potential value of compound 1 as a novel anti-adipogenic and anti-obesity agent.

  20. Aqueous extracts of the edible Gracilaria tenuistipitata are protective against H₂O₂-induced DNA damage, growth inhibition, and cell cycle arrest.

    Science.gov (United States)

    Yang, Jing-Iong; Yeh, Chi-Chen; Lee, Jin-Ching; Yi, Szu-Cheng; Huang, Hurng-Wern; Tseng, Chao-Neng; Chang, Hsueh-Wei

    2012-06-13

    Potential antioxidant properties of an aqueous extract of the edible red seaweed Gracilaria tenuistipitata (AEGT) against oxidative DNA damage were evaluated. The AEGT revealed several antioxidant molecules, including phenolics, flavonoids and ascorbic acid. In a cell-free assay, the extract exhibited 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity that significantly reduced H₂O₂-induced plasmid DNA breaks in a dose-response manner (P < 0.001). The AEGT also suppressed H₂O₂-induced oxidative DNA damage in H1299 cells by reducing the percentage of damaged DNA in a dose-response manner (P < 0.001) as measured by a modified alkaline comet-nuclear extract (comet-NE) assay. The MTT assay results showed that AEGT confers significant protection against H₂O₂-induced cytotoxicity and that AEGT itself is not cytotoxic (P < 0.001). Moreover, H₂O₂-induced cell cycle G2/M arrest was significantly released when cells were co-treated with different concentrations of AEGT (P < 0.001). Taken together, these findings suggest that edible red algae Gracilaria water extract can prevent H₂O₂-induced oxidative DNA damage and its related cellular responses.

  1. CARI III Inhibits Tumor Growth in a Melanoma-Bearing Mouse Model through Induction of G0/G1 Cell Cycle Arrest

    Directory of Open Access Journals (Sweden)

    Hye-Jin Park

    2014-09-01

    Full Text Available Mushroom-derived natural products have been used to prevent or treat cancer for millennia. In this study, we evaluated the anticancer effects of CARI (Cell Activation Research Institute III, which consists of a blend of mushroom mycelia from Phellinus linteus grown on germinated brown rice, Inonotus obliquus grown on germinated brown rice, Antrodia camphorata grown on germinated brown rice and Ganoderma lucidum. Here, we showed that CARI III exerted anti-cancer activity, which is comparable to Dox against melanoma in vivo. B16F10 cells were intraperitoneally injected into C57BL6 mice to develop solid intra-abdominal tumors. Three hundred milligrams of the CARI III/kg/day p.o. regimen reduced tumor weight, comparable to the doxorubicin (Dox-treated group. An increase in life span (ILS% = 50.88% was observed in the CARI III-administered group, compared to the tumor control group. CARI III demonstrates anti-proliferative activity against B16F10 melanoma cells through inducing G0/G1 cell cycle arrest. CARI III inhibits the expression of cyclin D1, CDK4 and CDK2 and induces p21. Therefore, CARI III could be a potential chemopreventive supplement to melanoma patients.

  2. Helicobacter pylori Induced Phosphatidylinositol-3-OH Kinase/mTOR Activation Increases Hypoxia Inducible Factor-1α to Promote Loss of Cyclin D1 and G0/G1 Cell Cycle Arrest in Human Gastric Cells

    Science.gov (United States)

    Canales, Jimena; Valenzuela, Manuel; Bravo, Jimena; Cerda-Opazo, Paulina; Jorquera, Carla; Toledo, Héctor; Bravo, Denisse; Quest, Andrew F. G.

    2017-01-01

    Helicobacter pylori (H. pylori) is a human gastric pathogen that has been linked to the development of several gastric pathologies, such as gastritis, peptic ulcer, and gastric cancer. In the gastric epithelium, the bacterium modifies many signaling pathways, resulting in contradictory responses that favor both proliferation and apoptosis. Consistent with such observations, H. pylori activates routes associated with cell cycle progression and cell cycle arrest. H. pylori infection also induces the hypoxia-induced factor HIF-1α, a transcription factor known to promote expression of genes that permit metabolic adaptation to the hypoxic environment in tumors and angiogenesis. Recently, however, also roles for HIF-1α in the repair of damaged DNA and inhibition of gene expression were described. Here, we investigated signaling pathways induced by H. pylori in gastric cells that favor HIF-1α expression and the consequences thereof in infected cells. Our results revealed that H. pylori promoted PI3K/mTOR-dependent HIF-1α induction, HIF-1α translocation to the nucleus, and activity as a transcription factor as evidenced using a reporter assay. Surprisingly, however, transcription of known HIF-1α effector genes evaluated by qPCR analysis, revealed either no change (LDHA and GAPDH), statistically insignificant increases SLC2A1 (GLUT-1) or greatly enhance transcription (VEGFA), but in an HIF-1α-independent manner, as quantified by PCR analysis in cells with shRNA-mediated silencing of HIF-1α. Instead, HIF-1α knockdown facilitated G1/S progression and increased Cyclin D1 protein half-life, via a post-translational pathway. Taken together, these findings link H. pylori-induced PI3K-mTOR activation to HIF-1α induced G0/G1 cell cycle arrest by a Cyclin D1-dependent mechanism. Thus, HIF-1α is identified here as a mediator between survival and cell cycle arrest signaling activated by H. pylori infection.

  3. Glycoprotein 5 of porcine reproductive and respiratory syndrome virus strain SD16 inhibits viral replication and causes G2/M cell cycle arrest, but does not induce cellular apoptosis in Marc-145 cells

    Energy Technology Data Exchange (ETDEWEB)

    Mu, Yang, E-mail: muyang@nwsuaf.edu.cn [Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A& F University, No. 22 Xinong Road, Yangling, Shaanxi 712100 (China); Experimental Station of Veterinary Pharmacology and Veterinary Biotechnology, Ministry of Agriculture of the People' s Republic of China, No. 22 Xinong Road, Yangling, Shaanxi 712100 (China); Li, Liangliang, E-mail: lifeiyang2007@126.com [Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A& F University, No. 22 Xinong Road, Yangling, Shaanxi 712100 (China); Experimental Station of Veterinary Pharmacology and Veterinary Biotechnology, Ministry of Agriculture of the People' s Republic of China, No. 22 Xinong Road, Yangling, Shaanxi 712100 (China); Zhang, Beibei, E-mail: diana851218@163.com [Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A& F University, No. 22 Xinong Road, Yangling, Shaanxi 712100 (China); Experimental Station of Veterinary Pharmacology and Veterinary Biotechnology, Ministry of Agriculture of the People' s Republic of China, No. 22 Xinong Road, Yangling, Shaanxi 712100 (China); Huang, Baicheng, E-mail: hbch228@163.com [Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A& F University, No. 22 Xinong Road, Yangling, Shaanxi 712100 (China); Experimental Station of Veterinary Pharmacology and Veterinary Biotechnology, Ministry of Agriculture of the People' s Republic of China, No. 22 Xinong Road, Yangling, Shaanxi 712100 (China); Gao, Jiming, E-mail: jimingao2006@163.com [Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A& F University, No. 22 Xinong Road, Yangling, Shaanxi 712100 (China); Experimental Station of Veterinary Pharmacology and Veterinary Biotechnology, Ministry of Agriculture of the People' s Republic of China, No. 22 Xinong Road, Yangling, Shaanxi 712100 (China); and others

    2015-10-15

    Cell apoptosis is common after infection with porcine reproductive and respiratory syndrome virus (PRRSV). PRRSV GP5 has been reported to induce cell apoptosis. To further understand the role of GP5 in PRRSV induced cell apoptosis, we established Marc-145 cell lines stably expressing full-length GP5, GP5{sup Δ84-96} (aa 84-96 deletion), and GP5{sup Δ97-119} (aa 97-119 deletion). Cell proliferation, cell cycle progression, cell apoptosis and virus replication in these cell lines were evaluated. Neither truncated nor full-length GP5 induced cell apoptosis in Marc-145 cells. However, GP5{sup Δ97-119}, but not full-length or GP5{sup Δ84-96}, induced a cell cycle arrest at the G2/M phase resulting in a reduction in the growth of Marc-145 cells. Additionally, GP5{sup Δ84-96} inhibited the replication of PRRSV in Marc-145 cells through induction of IFN-β. These findings suggest that PRRSV GP5 is not responsible for inducing cell apoptosis in Marc-145 cells under these experimental conditions; however it has other important roles in virus/host cell biology. - Highlights: • Marc-145 cell lines stable expression PRRSV GP5 or truncated GP5 were constructed. • GP5{sup Δ97-119} expression in Marc-145 cell induced cell cycle arrest at G2/M phase. • Expression of GP5 and truncated GP5 could not induce Marc-145 cells apoptosis. • PRRSV replication in Marc-145-GP5{sup Δ84-96} was significantly inhibited.

  4. Induction of p21CIP1 protein and cell cycle arrest after inhibition of Aurora B kinase is attributed to aneuploidy and reactive oxygen species.

    Science.gov (United States)

    Kumari, Geeta; Ulrich, Tanja; Krause, Michael; Finkernagel, Florian; Gaubatz, Stefan

    2014-06-01

    Cell cycle progression requires a series of highly coordinated events that ultimately lead to faithful segregation of chromosomes. Aurora B is an essential mitotic kinase, which is involved in regulation of microtubule-kinetochore attachments and cytokinesis. Inhibition of Aurora B results in stabilization of p53 and induction of p53-target genes such as p21 to inhibit proliferation. We have previously demonstrated that induction of p21 by p53 after inhibition of Aurora B is dependent on the p38 MAPK, which promotes transcriptional elongation of p21 by RNA Pol II. In this study, we show that a subset of p53-target genes are induced in a p38-dependent manner upon inhibition of Aurora B. We also demonstrate that inhibition of Aurora B results in down-regulation of E2F-mediated transcription and that the cell cycle arrest after Aurora B inhibition depends on p53 and pRB tumor suppressor pathways. In addition, we report that activation of p21 after inhibition of Aurora B is correlated with increased chromosome missegregation and aneuploidy but not with binucleation or tetraploidy. We provide evidence that p21 is activated in aneuploid cells by reactive oxygen species (ROS) and p38 MAPK. Finally, we demonstrate that certain drugs that act on aneuploid cells synergize with inhibitors of Aurora B to inhibit colony formation and oncogenic transformation. These findings provide an important link between aneuploidy and the stress pathways activated by Aurora B inhibition and also support the use of Aurora B inhibitors in combination therapy for treatment of cancer.

  5. Fibroblast growth factor 2 causes G2/M cell cycle arrest in ras-driven tumor cells through a Src-dependent pathway.

    Directory of Open Access Journals (Sweden)

    Jacqueline Salotti

    Full Text Available We recently reported that paracrine Fibroblast Growth Factor 2 (FGF2 triggers senescence in Ras-driven Y1 and 3T3(Ras mouse malignant cell lines. Here, we show that although FGF2 activates mitogenic pathways in these Ras-dependent malignant cells, it can block cell proliferation and cause a G2/M arrest. These cytostatic effects of FGF2 are inhibited by PD173074, an FGF receptor (FGFR inhibitor. To determine which downstream pathways are induced by FGF2, we tested specific inhibitors targeting mitogen-activated protein kinase (MEK, phosphatidylinositol 3 kinase (PI3K and protein kinase C (PKC. We show that these classical mitogenic pathways do not mediate the cytostatic activity of FGF2. On the other hand, the inhibition of Src family kinases rescued Ras-dependent malignant cells from the G2/M irreversible arrest induced by FGF2. Taken together, these data indicate a growth factor-sensitive point in G2/M that likely involves FGFR/Ras/Src pathway activation in a MEK, PI3K and PKC independent manner.

  6. Sesamin induces cell cycle arrest and apoptosis through the inhibition of signal transducer and activator of transcription 3 signalling in human hepatocellular carcinoma cell line HepG2.

    Science.gov (United States)

    Deng, Pengyi; Wang, Chen; Chen, Liulin; Wang, Cheng; Du, Yuhan; Yan, Xu; Chen, Mingjie; Yang, Guangxiao; He, Guangyuan

    2013-01-01

    Sesamin, one of the most abundant lignans in sesame seeds, has been shown to exhibit various pharmacological effects. The aim of this study was to elucidate whether sesamin promotes cell cycle arrest and induces apoptosis in HepG2 cells and further to explore the underlying molecular mechanisms. Here, we found that sesamin inhibited HepG2 cell growth by inducing G2/M phase arrest and apoptosis. Furthermore, sesamin suppressed the constitutive and interleukin (IL)-6-induced signal transducer and activator of transcription 3 (STAT3) signalling pathway in HepG2 cells, leading to regulate the downstream genes, including p53, p21, cyclin proteins and the Bcl-2 protein family. Our studies showed that STAT3 signalling played a key role in sesamin-induced G2/M phase arrest and apoptosis in HepG2 cells. These findings provided a molecular basis for understanding of the effects of sesamin in hepatocellular carcinoma tumour cell proliferation. Therefore, sesamin may thus be a potential chemotherapy drug for liver cancer.

  7. Neisseria meningitidis causes cell cycle arrest of human brain microvascular endothelial cells at S phase via p21 and cyclin G2.

    Science.gov (United States)

    Oosthuysen, Wilhelm F; Mueller, Tobias; Dittrich, Marcus T; Schubert-Unkmeir, Alexandra

    2016-01-01

    Microbial pathogens have developed several mechanisms to modulate and interfere with host cell cycle progression. In this study, we analysed the effect of the human pathogen Neisseria meningitidis on cell cycle in a brain endothelial cell line as well as in primary brain endothelial cells. We found that N.  Meningitidis causes an accumulation of cells in the S phase early at 3 and at 24 h post-infection that was paralleled by a decrease of cells in G2/M phase. Importantly, the outer membrane proteins of the colony opacity-associated (Opa) protein family as well as the Opc protein proved to trigger the accumulation of cells in the S phase. A focused cell cycle reverse transcription quantitative polymerase chain reaction-based array and integrated network analysis revealed changes in the abundance of several cell cycle regulatory mRNAs, including the cell cycle inhibitors p21(WAF1/CIP1) and cyclin G2. These alterations were reflected in changes in protein expression levels and/or relocalization in N. meningitidis-infected cells. Moreover, an increase in p21(WAF1/CIP1) expression was found to be p53 independent. Genetic ablation of p21(WAF1/CIP1) and cyclin G2 abrogated N. meningitidis-induced S phase accumulation. Finally, by measuring the levels of the biomarker 8-hydroxydeoxyguanosine and phosphorylation of the histone variant H2AX, we provide evidence that N. meningitidis induces oxidative DNA damage in infected cells.

  8. UV-B inhibition of hypocotyl growth in etiolated Arabidopsis thaliana seedlings is a consequence of cell cycle arrest initiated by photodimer accumulation.

    Science.gov (United States)

    Biever, Jessica J; Brinkman, Doug; Gardner, Gary

    2014-06-01

    Ultraviolet (UV) radiation is an important constituent of sunlight that determines plant morphology and growth. It induces photomorphogenic responses but also causes damage to DNA. Arabidopsis mutants of the endonucleases that function in nucleotide excision repair, xpf-3 and uvr1-1, showed hypersensitivity to UV-B (280-320nm) in terms of inhibition of hypocotyl growth. SOG1 is a transcription factor that functions in the DNA damage signalling response after γ-irradiation. xpf mutants that carry the sog1-1 mutation showed hypocotyl growth inhibition after UV-B irradiation similar to the wild type. A DNA replication inhibitor, hydroxyurea (HU), also inhibited hypocotyl growth in etiolated seedlings, but xpf-3 was not hypersensitive to HU. UV-B irradiation induced accumulation of the G2/M-specific cell cycle reporter construct CYCB1;1-GUS in wild-type Arabidopsis seedlings that was consistent with the expected accumulation of photodimers and coincided with the time course of hypocotyl growth inhibition after UV-B treatment. Etiolated mutants of UVR8, a recently described UV-B photoreceptor gene, irradiated with UV-B showed inhibition of hypocotyl growth that was not different from that of the wild type, but they lacked UV-B-specific expression of chalcone synthase (CHS), as expected from previous reports. CHS expression after UV-B irradiation was not different in xpf-3 compared with the wild type, nor was it altered after HU treatment. These results suggest that hypocotyl growth inhibition by UV-B light in etiolated Arabidopsis seedlings, a photomorphogenic response, is dictated by signals originating from UV-B absorption by DNA that lead to cell cycle arrest. This process occurs distinct from UVR8 and its signalling pathway responsible for CHS induction.

  9. PTEN and p53 cross-regulation induced by soy isoflavone genistein promotes mammary epithelial cell cycle arrest and lobuloalveolar differentiation.

    Science.gov (United States)

    Rahal, Omar M; Simmen, Rosalia C M

    2010-08-01

    The tumor suppressors phosphatase and tensin homologue deleted on chromosome ten (PTEN) and p53 are closely related to the pathogenesis of breast cancer, yet pathway-specific mechanisms underlying their participation in mediating the protective actions of dietary bioactive components on breast cancer risk are poorly understood. We recently showed that dietary exposure to the soy isoflavone genistein (GEN) induced PTEN expression in mammary epithelial cells in vivo and in vitro, consistent with the breast cancer preventive effects of soy food consumption. Here, we evaluated PTEN and p53 functional interactions in the nuclear compartment of mammary epithelial cells as a mechanism for mammary tumor protection by GEN. Using the non-tumorigenic human mammary epithelial cells MCF10-A, we demonstrate that GEN increased PTEN expression and nuclear localization. We show that increased nuclear PTEN levels initiated an autoregulatory loop involving PTEN-dependent increases in p53 nuclear localization, PTEN-p53 physical association, PTEN-p53 co-recruitment to the PTEN promoter region and p53 transactivation of PTEN promoter activity. The PTEN-p53 cross talk induced by GEN resulted in increased cell cycle arrest; decreased pro-proliferative cyclin D1 and pleiotrophin gene expression and the early formation of mammary acini, indicative of GEN promotion of lobuloalveolar differentiation. Our findings provide support to GEN-induced PTEN as both a target and regulator of p53 action and offer a mechanistic basis for PTEN pathway activation to underlie the antitumor properties of dietary factors, with important implications for reducing breast cancer risk.

  10. Cell cycle profiles of EcR, USP, HR3 and B cyclin mRNAs associated to 20E-induced G2 arrest of Plodia interpunctella imaginal wing cells.

    Science.gov (United States)

    Siaussat, D; Bozzolan, F; Queguiner, I; Porcheron, P; Debernard, S

    2005-04-01

    Using the IAL-PID2 cell line established from pupally committed imaginal wing discs of Plodia interpunctella, we have investigated the dynamics of cellular and molecular events involved in the G2/M arrest. We have first cloned a cDNA sequence named PIUSP-2 that likely encodes a homologue of the Ultraspiracle-2 isoform of Manduca sexta. When the IAL-PID2 cells were exposed to a 8 h 20E treatment applied at different times of the cell cycle, an optimal period of sensitivity of cells to 20E, in inducing G2 arrest, was determined at the S/G2 transition. Using cDNA probes specifically designed from Plodia B cyclin (PcycB), ecdysone receptor B1-isoform (PIEcR-B1) and HR3 transcription factor (PHR3), we provide evidence that the 20E-induced G2 arrest was correlated to a high induction of PHR3, PIEcR-B1, PIUSP-2 mRNAs at the S/G2 transition and a decrease in PcycB mRNA level at the end of G2 phase.

  11. A novel function of RNAs arising from the long terminal repeat of human endogenous retrovirus 9 in cell cycle arrest.

    Science.gov (United States)

    Xu, Lai; Elkahloun, Abdel G; Candotti, Fabio; Grajkowski, Andrzej; Beaucage, Serge L; Petricoin, Emanuel F; Calvert, Valerie; Juhl, Hartmut; Mills, Frederick; Mason, Karen; Shastri, Neal; Chik, Josh; Xu, Cynthia; Rosenberg, Amy S

    2013-01-01

    The human genome contains approximately 50 copies of the replication-defective human endogenous retrovirus 9 (ERV-9) and thousands of copies of its solitary long term repeat (sLTR) element. While some sLTRs are located upstream of critical genes and have enhancer activity, other sLTRs are located within introns and may be transcribed as RNAs. We found that intronic RNAs arising from U3 sLTRs of ERV-9 were expressed as both sense (S) and antisense (AS) transcripts in all human cells tested but that expression levels differed in malignant versus nonmalignant cells. In nonmalignant cells, AS was expressed at higher levels than S and at higher levels than in malignant cells; in malignant cells, AS was expressed at amounts equivalent to those of S RNA. Critically, U3 AS RNA was found to physically bind to key transcription factors for cellular proliferation, including NF-Y, p53, and sp1, indicating that such RNA transcripts may function as decoy targets or traps for NF-Y and thus inhibit the growth of human cancer cells. Indeed, short U3 oligodeoxynucleotides (ODNs) based on these RNA sequences ably inhibited proliferation of cancer cell lines driven by cyclins B1/B2, the gene targets of NF-Y.

  12. RBP-J-interacting and tubulin-associated protein induces apoptosis and cell cycle arrest in human hepatocellular carcinoma by activating the p53–Fbxw7 pathway

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Haihe [The Key Laboratory of Molecular Diagnosis in Laboratory Medicine, Department of Pathogenobiology, Daqing Branch of Harbin Medical University, Daqing 163319 (China); Yang, Zhanchun [Department of General Surgery of Fifth Clinical Hospital of Harbin Medical University, Daqing 163319 (China); Liu, Chunbo; Huang, Shishun; Wang, Hongzhi; Chen, Yingli [The Key Laboratory of Molecular Diagnosis in Laboratory Medicine, Department of Pathogenobiology, Daqing Branch of Harbin Medical University, Daqing 163319 (China); Chen, Guofu, E-mail: zhangyanjie3@aliyun.com [Department of General Surgery of Fifth Clinical Hospital of Harbin Medical University, Daqing 163319 (China)

    2014-11-07

    Highlights: • RITA overexpression increased protein expression of p53 and Fbxw7 and downregulated the expression of cyclin D1, cyclin E, CDK2, Hes-1 and NF-κB p65. • RITA can significantly inhibit the in vitro growth of SMMC7721 and HepG2 cells. • RITA exerts tumor-suppressive effects in hepatocarcinogenesis through induction of G0/G1 cell cycle arrest and apoptosis and suggest a therapeutic application of RITA in HCC. - Abstract: Aberrant Notch signaling is observed in human hepatocellular carcinoma (HCC) and has been associated with the modulation of cell growth. However, the role of Notch signaling in HCC and its underlying mechanism remain elusive. RBP-J-interacting and tubulin-associated (RITA) mediates the nuclear export of RBP-J to tubulin fibers and downregulates Notch-mediated transcription. In this study, we found that RITA overexpression increased protein expression of p53 and Fbxw7 and downregulated the expression of cyclin D1, cyclin E, CDK2, Hes-1 and NF-κB p65. These changes led to growth inhibition and induced G0/G1 cell cycle arrest and apoptosis in SMMC7721 and HepG2 cells. Our findings indicate that RITA exerts tumor-suppressive effects in hepatocarcinogenesis through induction of G0/G1 cell cycle arrest and apoptosis and suggest a therapeutic application of RITA in HCC.

  13. Persea declinata (Bl. Kosterm Bark Crude Extract Induces Apoptosis in MCF-7 Cells via G0/G1 Cell Cycle Arrest, Bcl-2/Bax/Bcl-xl Signaling Pathways, and ROS Generation

    Directory of Open Access Journals (Sweden)

    Putri Narrima

    2014-01-01

    Full Text Available Persea declinata (Bl. Kosterm is a member of the Lauraceae family, widely distributed in Southeast Asia. It is from the same genus with avocado (Persea americana Mill, which is widely consumed as food and for medicinal purposes. In the present study, we examined the anticancer properties of Persea declinata (Bl. Kosterm bark methanolic crude extract (PDM. PDM exhibited a potent antiproliferative effect in MCF-7 human breast cancer cells, with an IC50 value of 16.68 µg/mL after 48 h of treatment. We observed that PDM caused cell cycle arrest and subsequent apoptosis in MCF-7 cells, as exhibited by increased population at G0/G1 phase, higher lactate dehydrogenase (LDH release, and DNA fragmentation. Mechanistic studies showed that PDM caused significant elevation in ROS production, leading to perturbation of mitochondrial membrane potential, cell permeability, and activation of caspases-3/7. On the other hand, real-time PCR and Western blot analysis showed that PDM treatment increased the expression of the proapoptotic molecule, Bax, but decreased the expression of prosurvival proteins, Bcl-2 and Bcl-xL, in a dose-dependent manner. These findings imply that PDM could inhibit proliferation in MCF-7 cells via cell cycle arrest and apoptosis induction, indicating its potential as a therapeutic agent worthy of further development.

  14. Novel dihydrobenzofuro[4,5-b][1,8]naphthyridin-6-one derivative, MHY-449, induces cell cycle arrest and apoptosis via the downregulation of Akt in human lung cancer cells.

    Science.gov (United States)

    Lim, Hyun Sook; Kang, Yong Jung; Sung, Bokyung; Kim, Seon Hee; Kim, Min Jeong; Kim, Hye Rim; Kim, Seong Jin; Choi, Yung Hyun; Moon, Hyung Ryong; Chung, Hae Young; Kim, Nam Deuk

    2015-11-01

    The anticancer properties of MHY-449, a novel dihydrobenzofuro[4,5-b][1,8]naphthyridin-6-one derivative, in various human cancer cell lines have been previously reported. The aim of the present study was to investigate the activities of MHY-449 on human lung cancer cells in order to elucidate its underlying molecular mechanisms of action. The result showed that MHY-449 treatment inhibited cell growth in a time- and concentration‑dependent manner. Specifically, MHY-449 induced cell cycle arrest at the S phase, and the resulting increased sub-G1 fraction led to the induction of apoptosis, as determined by flow cytometric analysis and DNA fragmentation. In addition, MHY-449 was shown to induce alterations in the ratio of Bax/Bcl-2 protein expression, and contribute to the loss of mitochondrial membrane potential. These cellular events then triggered the caspase cascade and subsequent poly(ADP‑ribose) polymerase cleavage. The apoptotic cell death induced by MHY-449 was inhibited by pretreatment with Z-VAD‑FMK, a pan-caspase inhibitor. Moreover, MHY-449 downregulated the phosphorylation of Akt, and the phosphatidylinositol-3 kinase/Akt inhibitor LY294002 was found to enhance its induction of apoptosis. Taken together, the results suggested that MHY-449 exerts anticancer effects by promoting cell cycle arrest and apoptosis via the downregulation of Akt. Based on these data, MHY-449 serves as a potential candidate in the chemoprevention and/or treatment of lung cancer.

  15. Combination of Low Concentration of (−-Epigallocatechin Gallate (EGCG and Curcumin Strongly Suppresses the Growth of Non-Small Cell Lung Cancer in Vitro and in Vivo through Causing Cell Cycle Arrest

    Directory of Open Access Journals (Sweden)

    Wenbin Huang

    2013-06-01

    Full Text Available (−-Epigallocatechin gallate (EGCG and curcumin are two naturally derived agents that have been widely investigated worldwide. They exhibit their anti-tumor effects in many types of cancers. In the current study, the effect of the combination of the two agents on non-small cell lung cancer (NSCLC cells was investigated. The results revealed that at low concentrations, the combination of the EGCG and curcumin strongly enhanced cell cycle arrest. Flow cytometry analysis showed that the cells were arrested at G1 and S/G2 phases. Two main cell cycle related proteins cyclin D1 and cyclin B1 were significantly inhibited at the present of EGCG and curcumin. EdU (5-ethynyl-2'-deoxyuridine fluorescence staining showed that the DNA replication was significantly blocked. A clonal growth assay also confirmed a marked repression of cell growth. In a lung cancer xenograft node mice model, combination of EGCG and curcumin exhibited protective effect against weight loss due to tumor burden. Tumor growth was strongly repressed by the combination of the two agents, without causing any serious side-effect. Overall, these results strongly suggest that EGCG in combination with curcumin could be a candidate for chemoprevention agent of NSCLC.

  16. CDK5 Regulates Paclitaxel Sensitivity in Ovarian Cancer Cells by Modulating AKT Activation, p21Cip1- and p27Kip1-Mediated G1 Cell Cycle Arrest and Apoptosis.

    Directory of Open Access Journals (Sweden)

    Shu Zhang

    Full Text Available Cyclin-dependent kinase 5 (CDK5 is a cytoplasmic serine/ threonine kinase. Knockdown of CDK5 enhances paclitaxel sensitivity in human ovarian cancer cells. This study explores the mechanisms by which CDK5 regulates paclitaxel sensitivity in human ovarian cancers. Multiple ovarian cancer cell lines and xenografts were treated with CDK5 small interfering RNA (siRNA with or without paclitaxel to examine the effect on cancer cell viability, cell cycle arrest and tumor growth. CDK5 protein was measured by immunohistochemical staining of an ovarian cancer tissue microarray to correlate CDK5 expression with overall patient survival. Knockdown of CDK5 with siRNAs inhibits activation of AKT which significantly correlates with decreased cell growth and enhanced paclitaxel sensitivity in ovarian cancer cell lines. In addition, CDK5 knockdown alone and in combination with paclitaxel induced G1 cell cycle arrest and caspase 3 dependent apoptotic cell death associated with post-translational upregulation and nuclear translocation of TP53 and p27(Kip1 as well as TP53-dependent transcriptional induction of p21(Cip1 in wild type TP53 cancer cells. Treatment of HEYA8 and A2780 wild type TP53 xenografts in nu/nu mice with CDK5 siRNA and paclitaxel produced significantly greater growth inhibition than either treatment alone. Increased expression of CDK5 in human ovarian cancers correlates inversely with overall survival. CDK5 modulates paclitaxel sensitivity by regulating AKT activation, the cell cycle and caspase-dependent apoptosis. CDK5 inhibition can potentiate paclitaxel activity in human ovarian cancer cells.

  17. Novel Tools to Analyze the Function of Salmonella Effectors Show That SvpB Ectopic Expression Induces Cell Cycle Arrest in Tumor Cells

    Science.gov (United States)

    Mesa-Pereira, Beatriz; Medina, Carlos; Camacho, Eva María; Flores, Amando; Santero, Eduardo

    2013-01-01

    In order to further characterize its role in pathogenesis and to establish whether its overproduction can lead to eukaryotic tumor cell death, Salmonella strains able to express its virulence factor SpvB (an ADP-ribosyl transferase enzyme) in a salicylate-inducible way have been constructed and analyzed in different eukaryotic tumor cell lines. To do so, the bacterial strains bearing the expression system have been constructed in a ∆purD background, which allows control of bacterial proliferation inside the eukaryotic cell. In the absence of bacterial proliferation, salicylate-induced SpvB production resulted in activation of caspases 3 and 7 and apoptotic cell death. The results clearly indicated that controlled SpvB production leads to F-actin depolimerization and either G1/S or G2/M phase arrest in all cell lines tested, thus shedding light on the function of SpvB in Salmonella pathogenesis. In the first place, the combined control of protein production by salicylate regulated vectors and bacterial growth by adenine concentration offers the possibility to study the role of Salmonella effectors during eukaryotic cells infection. In the second place, the salicylate-controlled expression of SpvB by the bacterium provides a way to evaluate the potential of other homologous or heterologous proteins as antitumor agents, and, eventually to construct novel potential tools for cancer therapy, given that Salmonella preferentially proliferates in tumors. PMID:24205236

  18. Novel miR-5582-5p functions as a tumor suppressor by inducing apoptosis and cell cycle arrest in cancer cells through direct targeting of GAB1, SHC1, and CDK2.

    Science.gov (United States)

    An, Hyun-Ju; Kwak, Seo-Young; Yoo, Je-Ok; Kim, Jae-Sung; Bae, In-Hwa; Park, Myung-Jin; Cho, Mee-Yon; Kim, Joon; Han, Young-Hoon

    2016-10-01

    MicroRNAs (miRNAs) play pivotal roles in tumorigenesis as either tumor suppressors or oncogenes. In the present study, we discovered and demonstrated the tumor suppressive function of a novel miRNA miR-5582-5p. miR-5582-5p induced apoptosis and cell cycle arrest in cancer cells, but not in normal cells. GAB1, SHC1, and CDK2 were identified as direct targets of miR-5582-5p. Knockdown of GAB1/SHC1 or CDK2 phenocopied the apoptotic or cell cycle arrest-inducing function of miR-5582-5p, respectively. The expression of miR-5582-5p was lower in tumor tissues than in adjacent normal tissues of colorectal cancer patients, while the expression of the target proteins exhibited patterns opposite to that of miR-5582-5p. Intratumoral injection of a miR-5582-5p mimic or induced expression of miR-5582-5p in tumor cells suppressed tumor growth in HCT116 xenografts. Collectively, our results suggest a novel tumor suppressive function for miR-5582-5p and its potential applicability for tumor control.

  19. The ethyl acetate extract of Phellinus linteus grown on germinated brown rice induces G0/G1 cell cycle arrest and apoptosis in human colon carcinoma HT29 cells.

    Science.gov (United States)

    Park, Hye-Jin; Choi, Se Young; Hong, Se Mi; Hwang, Sung Gu; Park, Dong Ki

    2010-07-01

    It is well known that Phellinus linteus has a variety of biological functions, such as antitumor and immunomodulating activities. In our previous studies, we developed a P. linteus grown on germinated brown rice (PBR) and found that organic solvent extracts of PBR possessed immunomodulating activity to regulate a balance of cytokine network in mice. The components of PBR are ergosterol peroxide, gamma-aminobutyric acid (GABA) and Beta-glucan. In this study, we demonstrate that an organic solvent extract of P. linteus grown on PBR induced apoptotic cell death through the induction of G(0)/G(1) arrest of cell cycle and the apoptosis via DNA fragmentation in human colon carcinoma HT-29 cells. Cell death induced by the extract of P. linteus grown on PBR was shown to be associated with the upregulation of p21(CIP1/WAF1), the downregulation of cyclin D1, anti-apoptotic protein, Bcl-2, the release of cytochrome c, and the activation of caspase-9, caspase-3 and caspase-8. This study suggests that the ethyl acetate extract of P. linteus grown on PBR induces apoptosis accompanied by cell cycle arrest at G(0)/G(1) phase and regulates apoptosis-regulatory proteins, which may be applicable to anticancer therapy.

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

    Directory of Open Access Journals (Sweden)

    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.

  1. Hwanggeumchal sorghum induces cell cycle arrest, and suppresses tumor growth and metastasis through Jak2/STAT pathways in breast cancer xenografts.

    Directory of Open Access Journals (Sweden)

    Jin Hee Park

    Full Text Available BACKGROUND: Cancer is one of the highly virulent diseases known to humankind with a high mortality rate. Breast cancer is the most common cancer in women worldwide. Sorghum is a principal cereal food in many parts of the world, and is critical in folk medicine of Asia and Africa. In the present study, we analyzed the effects of HSE in metastatic breast cancer. METHODOLOGY/PRINCIPAL FINDINGS: Preliminary studies conducted on MDA-MB 231 and MCF-7 xenograft models showed tumor growth suppression by HSE. Western blotting studies conducted both in vivo and in vitro to check the effect of HSE in Jak/STAT pathways. Anti-metastatic effects of HSE were confirmed using both MDA-MB 231 and MCF-7 metastatic animal models. These studies showed that HSE can modulate Jak/STAT pathways, and it hindered the STAT5b/IGF-1R and STAT3/VEGF pathways not only by down-regulating the expression of these signal molecules and but also by preventing their phosphorylation. The expression of angiogenic factors like VEGF, VEGF-R2 and cell cycle regulators like cyclin D, cyclin E, and pRb were found down-regulated by HSE. In addition, it also targets Brk, p53, and HIF-1α for anti-cancer effects. HSE induced G1 phase arrest and migration inhibition in MDA-MB 231 cells. The metastasis of breast cancer to the lungs also found blocked by HSE in the metastatic animal model. CONCLUSIONS/SIGNIFICANCE: Usage of HS as a dietary supplement is an inexpensive natural cancer therapy, without any side effects. We strongly recommend the use of HS as an edible therapeutic agent as it possesses tumor suppression, migration inhibition, and anti-metastatic effects on breast cancer.

  2. The terminal basal mitosis of chicken retinal Lim1 horizontal cells is not sensitive to cisplatin-induced cell cycle arrest.

    Science.gov (United States)

    Shirazi Fard, Shahrzad; Thyselius, Malin; All-Ericsson, Charlotta; Hallböök, Finn

    2014-01-01

    For proper development, cells need to coordinate proliferation and cell cycle-exit. This is mediated by a cascade of proteins making sure that each phase of the cell cycle is controlled before the initiation of the next. Retinal progenitor cells divide during the process of interkinetic nuclear migration, where they undergo S-phase on the basal side, followed by mitoses on the apical side of the neuroepithelium. The final cell cycle of chicken retinal horizontal cells (HCs) is an exception to this general cell cycle behavior. Lim1 expressing (+) horizontal progenitor cells (HPCs) have a heterogenic final cell cycle, with some cells undergoing a terminal mitosis on the basal side of the retina. The results in this study show that this terminal basal mitosis of Lim1+ HPCs is not dependent on Chk1/2 for its regulation compared to retinal cells undergoing interkinetic nuclear migration. Neither activating nor blocking Chk1 had an effect on the basal mitosis of Lim1+ HPCs. Furthermore, the Lim1+ HPCs were not sensitive to cisplatin-induced DNA damage and were able to continue into mitosis in the presence of γ-H2AX without activation of caspase-3. However, Nutlin3a-induced expression of p21 did reduce the mitoses, suggesting the presence of a functional p53/p21 response in HPCs. In contrast, the apical mitoses were blocked upon activation of either Chk1/2 or p21, indicating the importance of these proteins during the process of interkinetic nuclear migration. Inhibiting Cdk1 blocked M-phase transition both for apical and basal mitoses. This confirmed that the cyclin B1-Cdk1 complex was active and functional during the basal mitosis of Lim1+ HPCs. The regulation of the final cell cycle of Lim1+ HPCs is of particular interest since it has been shown that the HCs are able to sustain persistent DNA damage, remain in the cell cycle for an extended period of time and, consequently, survive for months.

  3. Abnormal integrity of the nucleolus associated with cell cycle arrest owing to the temperature-sensitive ubiquitin-activating enzyme E1.

    Science.gov (United States)

    Sudha, T; Tsuji, H; Sameshima, M; Matsuda, Y; Kaneda, S; Nagai, Y; Yamao, F; Seno, T

    1995-03-01

    A mouse cell mutant, ts85, containing the temperature-sensitive ubiquitin-activating enzyme was arrested in G2 phase at the non-permissive temperature. In the arrested cells, azure C, a nucleolus-specific stain, revealed a U-shaped or ring-shaped arrangement of nucleolar lobes with an unstained region in the center. Silver staining of the nucleolar organizer region (NOR) and fluorescence in situ hybridization (FISH) with rDNA both gave signals in azure C-positive regions. Electron microscopic examination revealed a cloud of unidentified electron-dense particles (diameter approximately 70 nm) in the azure C-negative center space. When the arrested cells were released into M-phase, we observed the association of NOR-bearing chromosomes with a pulverization-like abnormality. FISH with rDNA and NOR silver staining demonstrated that the pulverization-like abnormality was restricted to NORs. The frequent occurrence of persistent nucleolar material in prophase and prometaphase of the stressed cells after release indicated a delayed dissociation of the nucleolus that brought about the abnormal chromosomes in M-phase. ts85 cells transfected with the mouse E1 cDNA recovered growth at the non-permissive temperature and no longer showed abnormal nucleolar morphology. It seems that the ubiquitin system plays a role in the dissolution of the nucleolus, possibly involving the NOR-bearing chromosomes.

  4. Ziyuglycoside I Inhibits the Proliferation of MDA-MB-231 Breast Carcinoma Cells through Inducing p53-Mediated G2/M Cell Cycle Arrest and Intrinsic/Extrinsic Apoptosis

    Science.gov (United States)

    Zhu, Xue; Wang, Ke; Zhang, Kai; Zhang, Ting; Yin, Yongxiang; Xu, Fei

    2016-01-01

    Background: Due to the aggressive clinical behavior, poor outcome, and lack of effective specific targeted therapies, triple-negative breast cancer (TNBC) has currently been recognized as one of the most malignant types of tumors. In the present study, we investigated the cytotoxic effect of ziyuglycoside I, one of the major components extracted from Chinese anti-tumor herbal Radix Sanguisorbae, on the TNBC cell line MDA-MB-231. Methods: The underlying molecular mechanism of the cytotoxic effect ziyuglycoside I on MDA-MB-231 cells was investigated with cell viability assay, flow cytometric analysis and Western blot. Results: Compared to normal mammary gland Hs 578Bst cells, treatment of ziyuglycoside I resulted in a significant growth inhibitory effect on MDA-MB-231 cells. Ziyuglycoside I induced the G2/M phase arrest and apoptosis of MDA-MB-231 cells in a dose-dependent manner. These effects were found to be partially mediated through the up-regulation of p53 and p21WAF1, elevated Bax/Bcl-2 ratio, and the activation of both intrinsic (mitochondrial-initiated) and extrinsic (Fas/FasL-initiated) apoptotic pathways. Furthermore, the p53 specific siRNA attenuated these effects. Conclusion: Our study suggested that ziyuglycoside I-triggered MDA-MB-231 cell cycle arrest and apoptosis were probably mediated by p53. This suggests that ziyuglycoside I might be a potential drug candidate for treating TNBC. PMID:27879682

  5. Ziyuglycoside I Inhibits the Proliferation of MDA-MB-231 Breast Carcinoma Cells through Inducing p53-Mediated G2/M Cell Cycle Arrest and Intrinsic/Extrinsic Apoptosis

    Directory of Open Access Journals (Sweden)

    Xue Zhu

    2016-11-01

    Full Text Available Background: Due to the aggressive clinical behavior, poor outcome, and lack of effective specific targeted therapies, triple-negative breast cancer (TNBC has currently been recognized as one of the most malignant types of tumors. In the present study, we investigated the cytotoxic effect of ziyuglycoside I, one of the major components extracted from Chinese anti-tumor herbal Radix Sanguisorbae, on the TNBC cell line MDA-MB-231. Methods: The underlying molecular mechanism of the cytotoxic effect ziyuglycoside I on MDA-MB-231 cells was investigated with cell viability assay, flow cytometric analysis and Western blot. Results: Compared to normal mammary gland Hs 578Bst cells, treatment of ziyuglycoside I resulted in a significant growth inhibitory effect on MDA-MB-231 cells. Ziyuglycoside I induced the G2/M phase arrest and apoptosis of MDA-MB-231 cells in a dose-dependent manner. These effects were found to be partially mediated through the up-regulation of p53 and p21WAF1, elevated Bax/Bcl-2 ratio, and the activation of both intrinsic (mitochondrial-initiated and extrinsic (Fas/FasL-initiated apoptotic pathways. Furthermore, the p53 specific siRNA attenuated these effects. Conclusion: Our study suggested that ziyuglycoside I-triggered MDA-MB-231 cell cycle arrest and apoptosis were probably mediated by p53. This suggests that ziyuglycoside I might be a potential drug candidate for treating TNBC.

  6. 4-O-Methylhonokiol Protects HaCaT Cells from TGF-β1-Induced Cell Cycle Arrest by Regulating of Canonical and Non-Canonical Pathways of TGF-β Signaling.

    Science.gov (United States)

    Kim, Sang-Cheol; Kang, Jung-Il; Hyun, Jin-Won; Kang, Ji-Hoon; Koh, Young-Sang; Kim, Young-Heui; Kim, Ki-Ho; Ko, Ji-Hee; Yoo, Eun-Sook; Kang, Hee-Kyoung

    2017-02-13

    4-O-methylhonokiol, a neolignan compound from Magnolia Officinalis, has been reported to have various biological activities including hair growth promoting effect. However, although transforming growth factor-β (TGF-β) signal pathway has an essential role in the regression induction of hair growth, the effect of 4-O-methylhonokiol on the TGF-β signal pathwayhas not yet been elucidated. We thus examined the effect of 4-O-methylhonokiol on TGF-β-induced canonical and noncanonical pathways in HaCaT human keratinocytes. When HaCaT cells were pretreated with 4-O-methylhonokiol, TGF-β1-induced G1/G0 phase arrest and TGF- β1-induced p21 expression were decreased. Moreover, 4-O-methylhonokiol inhibited nuclear translocation of Smad2/3, Smad4 and Sp1 in TGF-β1-induced canonical pathway. We observed that ERK phosphorylation by TGF-β1 was significantly attenuated by treatment with 4-O-methylhonokiol. 4-O-methylhonokiol inhibited TGF-β1-induced reactive oxygen species (ROS) production and reduced the increase of NADPH oxidase 4 (NOX4) mRNA level in TGF-β1-induced noncanonical pathway. These results indicate that 4-O-methylhonokiol could inhibit TGF-β1-induced cell cycle arrest through inhibition of canonical and noncanonical pathways in human keratinocyte HaCaT cell and that 4-O-methylhonokiol might have protective action on TGF-β1-induced cell cycle arrest.

  7. Bothrops jararaca and Bothrops erythromelas Snake Venoms Promote Cell Cycle Arrest and Induce Apoptosis via the Mitochondrial Depolarization of Cervical Cancer Cells

    Directory of Open Access Journals (Sweden)

    Emanuelly Bernardes-Oliveira

    2016-01-01

    Full Text Available Bothrops jararaca (BJ and Bothrops erythromelas (BE are viper snakes found in South-Southeast and Northeast regions of Brazil, respectively. Snake venoms are bioactive neurotoxic substances synthesized and stored by venom glands, with different physiological and pharmacological effects, recently suggesting a possible preference for targets in cancer cells; however, mechanisms of snakes have been little studied. Here, we investigated the mechanism responsible for snake crude venoms toxicity in cultured cervical cancer cells SiHa and HeLa. We show that BJ and BE snake crude venoms exert cytotoxic effects to these cells. The percentage of apoptotic cells and cell cycle analysis and cell proliferation were assessed by flow cytometry and MTT assay. Detection of mitochondrial membrane potential (Rhodamine-123, nuclei morphological change, and DNA fragmentation were examined by staining with DAPI. The results showed that both the BJ and BE venoms were capable of inhibiting tumor cell proliferation, promoting cytotoxicity and death by apoptosis of target SiHa and HeLa cells when treated with BJ and BE venoms. Furthermore, data revealed that both BJ venoms in SiHa cell promoted nuclear condensation, fragmentation, and formation of apoptotic bodies by DAPI assay, mitochondrial damage by Rhodamine-123, and cell cycle block in the G1-G0 phase. BJ and BE venoms present anticancer potential, suggesting that both Bothrops venoms could be used as prototypes for the development of new therapies.

  8. Inactivation of Cdk1/Cyclin B in metaphase-arrested mouse FT210 cells induces exit from mitosis without chromosome segregation or cytokinesis and allows passage through another cell cycle.

    Science.gov (United States)

    Paulson, James R

    2007-04-01

    It is well known that inactivation of Cdk1/Cyclin B is required for cells to exit mitosis. The work reported here tests the hypothesis that Cdk1/Cyclin B inactivation is not only necessary but also sufficient to induce mitotic exit and reestablishment of the interphase state. This hypothesis predicts that inactivation of Cdk1 in metaphase-arrested cells will induce the M to G1-phase transition. It is shown that when mouse FT210 cells (in which Cdk1 is temperature-sensitive) are arrested in metaphase and then shifted to their non-permissive temperature, they rapidly exit mitosis as evidenced by reassembly of interphase nuclei, decondensation of chromosomes, and dephosphorylation of histones H1 and H3. The resulting interphase cells are functionally normal as judged by their ability to progress through another cell cycle. However, they have double the normal number of chromosomes because they previously bypassed anaphase, chromosome segregation, and cytokinesis. These results, taken together with other observations in the literature, strongly suggest that in mammalian cells, inactivation of Cdk1/cyclin B is the trigger for mitotic exit and reestablishment of the interphase state.

  9. The inhibition of activated hepatic stellate cells proliferation by arctigenin through G0/G1 phase cell cycle arrest: persistent p27(Kip1) induction by interfering with PI3K/Akt/FOXO3a signaling pathway.

    Science.gov (United States)

    Li, Ao; Wang, Jun; Wu, Mingjun; Zhang, Xiaoxun; Zhang, Hongzhi

    2015-01-15

    Proliferation of hepatic stellate cells (HSCs) is vital for the development of fibrosis during liver injury. In this study, we describe that arctigenin (ATG), a major bioactive component of Fructus Arctii, exhibited selective cytotoxic activity via inhibiting platelet-derived growth factor-BB (PDGF-BB)-activated HSCs proliferation and arrested cell cycle at G0/G1 phase, which could not be observed in normal human hepatocytes in vitro. The cyclin-dependent kinase (CDK) 4/6 activities could be strongly inhibited by ATG through down-regulation of cyclin D1 and CDK4/6 expression in early G1 phase arrest. In the ATG-treated HSCs, the expression level of p27(Kip1) and the formation of CDK2-p27(Kip1) complex were also increased. p27(Kip1) silencing significantly attenuated the effect of ATG, including cell cycle arrest and suppression of proliferation in activated HSCs. We also found that ATG suppressed PDGF-BB-induced phosphorylation of Akt and its downstream transcription factor Forkhead box O 3a (FOXO3a), decreased binding of FOXO3a to 14-3-3 protein, and stimulated nuclear translocation of FOXO3a in activated HSCs. Furthermore, knockdown of FOXO3a expression by FOXO3a siRNA attenuated ATG-induced up-regulation of p27(Kip1) in activated HSCs. All the above findings suggested that ATG could increase the levels of p27(Kip1) protein through inhibition of Akt and improvement of FOXO3a activity, in turn inhibited the CDK2 kinase activity, and eventually caused an overall inhibition of HSCs proliferation.

  10. Proliferation inhibition, cell cycle arrest and apoptosis induced in HL-60 HL-60HL-60 HL-60 cells by a natural diterpene ester from Daphne mucronata

    Directory of Open Access Journals (Sweden)

    R Yazdanparast

    2011-05-01

    Full Text Available "n  "nBackground and the purpose of the study: Gnidilatimonoein (Gn, a new diterpene ester from Daphne mucronata, possesses strong anti-metastasis and anti-tumor activities. In this study, its apoptosis and differentiation capabilities were evaluated by using the leukemia HL-60 cell line. "nMaterial and methods: Cell prolifaration inhibition was estimated by MTT assay. The occurrence of apoptosis was evaluated by EtBr/AO double staining technique, cell cycle analyses and detection of apoptotic cells by Annexin V-FITC and propodium iodide (PI. Differentiation of the cells was determined by NBT reduction assay and the expression of specific cell surface markers such as CD14 and CD11b, were analyzed by flow cytometry.   "nResults: The drug decreased the growth of the cells dose- and time- dependently and the IC50 was found to be 1.3 µM. Our data suggested that Gn induced both monocytic differentiation  and apoptosis among HL-60 cells. In addition, cell cycle analyses showed an increase in G1 phase population by 24 hrs, which was gradually replaced by Sub-G1 cell population (apoptotic cells by 72 hrs. "nConclusion: Based on these data, the Gn-treated HL-60 cells displayed differentiation-dependent apoptosis. Thus, Gn might be a good candidate for differentiation therapy of leukemia, pending full biological evaluation of the compound among the wide array of leukemia cells. "nevaluation of the compound among the wide array of leukemia cells.

  11. Ethyl acetate fraction of Garcina epunctata induces apoptosis in human promyelocytic cells (HL-60) through the ROS generation and G0/G1 cell cycle arrest: a bioassay-guided approach.

    Science.gov (United States)

    Constant Anatole, Pieme; Guru, Santoh Kumar; Bathelemy, Ngamegni; Jeanne, Ngogang; Bhushan, Shashi; Murayama, Tetsuya; Saxena, Ajit Kumar

    2013-11-01

    Number of deaths due to cancer diseases is increasing in the world. There is an urgent need to develop alternative therapeutic measures against the disease. Our study reports the cytotoxicity activity of Garcina epunctata (gutifferae) in human promyelocytic leukemia cells (HL-60) and prostate cancer cells (PC-3) was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT). Changes in mitochondrial membrane potential (MMP), reactive oxygen species (ROS) and morphological changes associated with apoptosis were examined by flow cytometry and Hoescht staining respectively. The results of in vitro antiproliferative screening of fractions and extract from G. epunctata indicated that three fractions inhibited the viability of PC-3 cells with IC₅₀ varied from 50 to 88 μ/ml while two fractions inhibited the proliferation of HL-60 cells with IC₅₀ range between 47.5 and 12 μg/ml. Among the entire fraction tested, Hex-EtOAc (75:25) showed cytotoxic effects on the two cell lines and EtOAc fraction was most active only HL-60 cells (12 μg/ml). Treatment of HL-60 cells with G. epunctata (20, 50, 100 μg/ml) for 24 h led to a significant dose-dependent increase in the percentage of cells in sub-G1 phase by analysis of the content of DNA in cells, and a number of apoptotic bodies containing nuclear fragments were observed in cells treated with 100 μg/ml. The EtOAc fraction of G. epunctata treatment significantly arrested HL-60 cells at the G0/G1 phase (pHL-60 cells, leading to cell cycle arrest and programmed cell death, which was confirmed to occur through the mitochondrial pathway.

  12. Targeting mixed lineage kinases in ER-positive breast cancer cells leads to G2/M cell cycle arrest and apoptosis.

    Science.gov (United States)

    Wang, Limin; Gallo, Kathleen A; Conrad, Susan E

    2013-08-01

    Estrogen receptor (ER)-positive tumors represent the most common type of breast cancer, and ER-targeted therapies such as antiestrogens and aromatase inhibitors have therefore been widely used in breast cancer treatment. While many patients have benefited from these therapies, both innate and acquired resistance continue to be causes of treatment failure. Novel targeted therapeutics that could be used alone or in combination with endocrine agents to treat resistant tumors or to prevent their development are therefore needed. In this report, we examined the effects of inhibiting mixed-lineage kinase (MLK) activity on ER-positive breast cancer cells and non-tumorigenic mammary epithelial cells. Inhibition of MLK activity with the pan-MLK inhibitor CEP-1347 blocked cell cycle progression in G2 and early M phase, and induced apoptosis in three ER-positive breast cancer cell lines, including one with acquired antiestrogen resistance. In contrast, it had no effect on the cell cycle or apoptosis in two non-tumorigenic mammary epithelial cell lines. CEP-1347 treatment did not decrease the level of active ERK or p38 in any of the cell lines tested. However, it resulted in decreased JNK and NF-κB activity in the breast cancer cell lines. A JNK inhibitor mimicked the effects of CEP-1347 in breast cancer cells, and overexpression of c-Jun rescued CEP-1347-induced Bax expression. These results indicate that proliferation and survival of ER-positive breast cancer cells are highly dependent on MLK activity, and suggest that MLK inhibitors may have therapeutic efficacy for ER-positive breast tumors, including ones that are resistant to current endocrine therapies.

  13. Esculetin, a natural coumarin compound, evokes Ca(2+) movement and activation of Ca(2+)-associated mitochondrial apoptotic pathways that involved cell cycle arrest in ZR-75-1 human breast cancer cells.

    Science.gov (United States)

    Chang, Hong-Tai; Chou, Chiang-Ting; Lin, You-Sheng; Shieh, Pochuen; Kuo, Daih-Huang; Jan, Chung-Ren; Liang, Wei-Zhe

    2016-04-01

    Esculetin (6,7-dihydroxycoumarin), a derivative of coumarin compound, is found in traditional medicinal herbs. It has been shown that esculetin triggers diverse cellular signal transduction pathways leading to regulation of physiology in different models. However, whether esculetin affects Ca(2+) homeostasis in breast cancer cells has not been explored. This study examined the underlying mechanism of cytotoxicity induced by esculetin and established the relationship between Ca(2+) signaling and cytotoxicity in human breast cancer cells. The results showed that esculetin induced concentration-dependent rises in the intracellular Ca(2+) concentration ([Ca(2+)]i) in ZR-75-1 (but not in MCF-7 and MDA-MB-231) human breast cancer cells. In ZR-75-1 cells, this Ca(2+) signal response was reduced by removing extracellular Ca(2+) and was inhibited by the store-operated Ca(2+) channel blocker 2-aminoethoxydiphenyl borate (2-APB). In Ca(2+)-free medium, pre-treatment with the endoplasmic reticulum Ca(2+) pump inhibitor thapsigargin (TG) abolished esculetin-induced [Ca(2+)]i rises. Conversely, incubation with esculetin abolished TG-induced [Ca(2+)]i rises. Esculetin induced cytotoxicity that involved apoptosis, as supported by the reduction of mitochondrial membrane potential and the release of cytochrome c and the proteolytic activation of caspase-9/caspase-3, which were partially reversed by pre-chelating cytosolic Ca(2+) with 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid-acetoxymethyl ester (BAPTA-AM). Moreover, esculetin increased the percentage of cells in G2/M phase and regulated the expressions of p53, p21, CDK1, and cyclin B1. Together, in ZR-75-1 cells, esculetin induced [Ca(2+)]i rises by releasing Ca(2+) from the ER and causing Ca(2+) influx through 2-APB-sensitive store-operated Ca(2+) entry. Furthermore, esculetin activated Ca(2+)-associated mitochondrial apoptotic pathways that involved G2/M cell cycle arrest. Graphical abstract The summary of esculetin

  14. Computerized video time lapse study of cell cycle delay and arrest, mitotic catastrophe, apoptosis and clonogenic survival in irradiated 14-3-3sigma and CDKN1A (p21) knockout cell lines.

    Science.gov (United States)

    Chu, Kenneth; Teele, Noella; Dewey, Michael W; Albright, Norman; Dewey, William C

    2004-09-01

    .e. metabolic activity. Thus mitotic catastrophe itself is not a direct mode of death. Instead, apoptosis during interphase of both uninucleated and polyploid cells was the primary mode of death observed in the four cell types. Knocking out either CDKN1A or 14-3-3sigma increased the amount of cell death at 96 h, from 52% to approximately 70%, with an even greater increase to 90% when both genes were knocked out. Thus, in addition to effects of CDKN1A and 14-3-3sigma expression on transient cell cycle delay, CDKN1A has both an anti-proliferative and anti-apoptosis function, while 14-3-3sigma has only an anti-apoptosis function. Finally, the large alterations in the amounts of cell death did not correlate overall with the small alterations in clonogenic survival (dose-modifying ratios of 1.05-1.13); however, knocking out CDKN1A resulted in a decrease in arrested cells and an increase in survival, while knocking out 14-3-3sigma resulted in an increase in apoptosis and a decrease in survival.

  15. A New Perspective for Osteosarcoma Therapy: Proteasome Inhibition by MLN9708/2238 Successfully Induces Apoptosis and Cell Cycle Arrest and Attenuates the Invasion Ability of Osteosarcoma Cells in Vitro

    Directory of Open Access Journals (Sweden)

    Renhao Liu

    2017-01-01

    Full Text Available Background: The proteasome exists in all eukaryotic cells and provides the main route of intracellular proteins degradation involved in cell growth and apoptosis. Proteasome inhibition could block protein degradation pathways and disturb regulatory networks, possibly leading to profound effects on cell growth, particularly in cancer cells. A proteasome inhibitor with an appropriate toxicity index for malignant cells rather than normal cells would be an attractive anticancer therapy. Methods: The human osteosarcoma (OS cell lines MG-63 and Saos-2 and normal osteoblast cells were used to study the antitumour activity of the proteasome inhibitor MLN9708/2238. Results: MLN2238 inhibited cell growth, induced cell cycle arrest and apoptosis, and attenuated the invasion abilities of MG-63 and Saos-2 cells, with little cytotoxicity to normal cells. In addition, MLN2238 promoted antitumour mechanisms including the accumulation of E2F1, P53, P21 and other negative G2/M checkpoint proteins; up-regulated the relative expression ratio of BAX/BCL-2, APAF-1 and pro-apoptotic proteins of the BCL-2 family; triggered mitochondrial outer membrane permeabilization (MOMP; down-regulated BCL-2 and XIAP; activated caspase3/8/9; and suppressed MMP2/9 expression and secretion levels. Conclusions: The proteasome may be a novel biochemical target for OS treatment in vitro. Our study provides a promising mechanistic framework for MLN9708/2238 in OS treatment, supporting its clinical development.

  16. The Dietary Flavonoid Fisetin Causes Cell Cycle Arrest, Caspase-Dependent Apoptosis, and Enhanced Cytotoxicity of Chemotherapeutic Drugs in Triple-Negative Breast Cancer Cells.

    Science.gov (United States)

    Smith, Matthew L; Murphy, Kaylee; Doucette, Carolyn D; Greenshields, Anna L; Hoskin, David W

    2016-08-01

    Fisetin (3,3',4',7-tetrahydroxyflavone), a flavonoid found in a number of fruits and vegetables, has diverse biological activities, including cytotoxic effects on cancer cells. In this study, we investigated the effect of fisetin on triple-negative breast cancer (TNBC) cells. TNBC has a poorer prognosis than other types of breast cancer and treatment options for this disease are limited. Fisetin inhibited the growth of MDA-MB-468 and MDA-MB-231 TNBC cells, as well as their ability to form colonies, without substantially affecting the growth of non-malignant cells. In addition, fisetin inhibited the growth of estrogen receptor-bearing MCF-7 breast cancer cells and human epidermal growth factor receptor 2-overexpressing SK-BR-3 breast cancer cells. Fisetin inhibited TNBC cell division and induced apoptosis, which was associated with mitochondrial membrane permeabilization and the activation of caspase-9 and caspase-8, as well as the cleavage of poly(ADP-ribose) polymerase-1. Induction of caspase-dependent apoptosis by fisetin was confirmed by reduced killing of TNBC cells in the presence of the pan-caspase inhibitors Z-VAD-FMK and BOC-D-FMK. Decreased phosphorylation of histone H3 at serine 10 in fisetin-treated TNBC cells at G2/M phase of the cell cycle suggested that fisetin-induced apoptosis was the result of Aurora B kinase inhibition. Interestingly, the cytotoxic effect of cisplatin, 5-fluorouracil, and 4-hydroxycyclophosphamide metabolite of cyclophosphamide on TNBC cells was increased in the presence of fisetin. These findings suggest that further investigation of fisetin is warranted for possible use in the management of TNBC. J. Cell. Biochem. 117: 1913-1925, 2016. © 2016 Wiley Periodicals, Inc.

  17. Replicatively senescent cells are arrested in G1 and G2 phases

    Science.gov (United States)

    Mao, Zhiyong; Ke, Zhonghe; Gorbunova, Vera; Seluanov, Andrei

    2012-01-01

    Most human somatic cells do not divide indefinitely but enter a terminal growth arrest termed replicative senescence. Replicatively senescent cells are generally believed to arrest in G1 or G0 stage of the cell cycle. While doing cell cycle analysis on three different lines of normal human fibroblasts we observed that 36-60% of the replicatively senescent cells had 4N DNA content. Only up to 5% of senescent cells had more than one nucleus ruling out the possibility that the 4N cell population were G1-arrested bi-nucleated cells. Furthermore, it is unlikely that the 4N cells are tetraploids, because actively dividing pre-senescent cultures lacked the 8N tetraploid G2 population. Collectively these results suggest that the 4N population consists of G2 arrested cells. The notion that a large fraction of senescent cell population is arrested in G2 is important for understanding the biology of replicative senescence. PMID:22745179

  18. Ent-11α-Hydroxy-15-oxo-kaur-16-en-19-oic-acid Inhibits Growth of Human Lung Cancer A549 Cells by Arresting Cell Cycle and Triggering Apoptosis

    Institute of Scientific and Technical Information of China (English)

    Li Li; George G Chen; Ying-nian Lu; Yi Liu; Ke-feng Wu; Xian-ling Gong; Zhan-ping Gou; Ming-yue Li; Nian-ci Liang

    2012-01-01

    Objective:To examine the apoptotic effect of ent-11α-hydroxy-15-oxo-kaur-16-en-19-oic-acid (5F),a compound isolated from Pteris semipinnata L(PsL),in human lung cancer A549 cells.Methods:A549 cells were treated with 5F (0-80 μg/ml) for different time periods.Cytotoxicity was examined using a MTT method.Cell cycle was examined using propidium iodide staining.Apoptosis was examined using Hoechst 33258 staining,enzyme-linked immunosorbent assay (ELISA) and caspase-3 activity analysis.Expression of representative apoptosis-related proteins was evaluated by Western blot analysis.Reactive oxygen species (ROS) level was measured using standard protocols.Potential interaction of 5F with cisplatin was also examined.Results:5F inhibited the proliferation of A549 cells in a concentration- and time-dependent manner.5F increased the accumulation of cells in sub-G1 phase and arrested the cells in the G2 phase.Exposure to 5F induced morphological changes and DNA fragmentation that are characteristic of apoptosis.The expression of p21 was increased.5F exposure also increased Bax expression,release of cytochrome c and apoptosis inducing factor (AIF),and activation of caspase-3.5F significantly sensitized the cells to cisplatin toxicity Interestingly,treatment with 5F did not increase ROS,but reduced ROS production induced by cisplatin.Conclusion:SF could inhibit the proliferation of A549 cells by arresting the cells in G2 phase and by inducing mitochondrial-mediated apoptosis.

  19. External Qi of Yan Xin Qigong Inhibits Activation of Akt, Erk1/2 and NF-ĸB and Induces Cell Cycle Arrest and Apoptosis in Colorectal Cancer Cells

    Directory of Open Access Journals (Sweden)

    Xin Yan

    2013-01-01

    Full Text Available Background/Aims: Colorectal cancer (CRC is the second leading cause of cancer death in the Western countries. Novel approaches of treatment are needed for CRC. The purpose of the present study was to investigate cytotoxic effect of external Qi of Yan Xin Qigong (YXQ-EQ on human colorectal cancer cells. Methods: The effect of YXQ-EQ on viability, cell cycle progression and apoptosis in colorectal cancer HT-29 cells was investigated. Phosphorylation of Akt and Erk1/2, activation of NF-ĸB and the expression of proteins involved in regulation of cell cycle and apoptosis were examined by Western blot analysis. Results: YXQ-EQ markedly decreased viability and blocked colony formation of HT-29 cells. YXQ-EQ downregulated cyclin D1 expression and increased accumulation of cyclin-dependent kinase inhibitors p21Cip1 and p27Kip1, resulting in G1 cell cycle arrest. YXQ-EQ induced apoptosis in HT-29 cells in association with decreased expression of antiapoptotic proteins Bcl-xL, XIAP, survivin and Mcl-1 and elevated expression of proapoptotic protein Bax. YXQ-EQ significantly repressed phosphorylation of Akt and Erk1/2 and NF-ĸB activation in HT-29 cells, suggesting that YXQ-EQ may exert cytotoxic effect through regulating signaling pathways critical for cell proliferation and survival. Furthermore, YXQ-EQ treated PBS and an YXQ-EQ treated plant extract induced apoptosis in HT-29 cells. Conclusion: These findings show that YXQ-EQ has potent cytotoxic effect on HT-29 cells and suggest that YXQ-EQ could be potentially used for colorectal cancer treatment either directly or indirectly via carriers.

  20. 1-(2,6-Dihydroxy-4-methoxyphenyl-2-(4-hydroxyphenyl Ethanone-Induced Cell Cycle Arrest in G1/G0 in HT-29 Cells Human Colon Adenocarcinoma Cells

    Directory of Open Access Journals (Sweden)

    Ma Ma Lay

    2014-01-01

    Full Text Available 1-(2,6-Dihydroxy-4-methoxyphenyl-2-(4-hydroxyphenyl ethanone (DMHE was isolated from the ethyl acetate fraction of Phaleria macrocarpa (Scheff. Boerl fruits and the structure confirmed by GC-MS (gas chromatography-mass spectrometry and NMR (nuclear magnetic resonance analysis. This compound was tested on the HT-29 human colon adenocarcinoma cell line using MTT (method of transcriptional and translational cell proliferation assay. The results of MTT assay showed that DMHE exhibited good cytotoxic effect on HT-29 cells in a dose- and time-dependent manner but no cytotoxic effect on the MRC-5 cell line after 72 h incubation. Morphological features of apoptotic cells upon treatment by DMHE, e.g., cell shrinkage and membrane blebbing, were examined by an inverted and phase microscope. Other features, such as chromatin condension and nuclear fragmentation were studied using acridine orange and propidium iodide staining under the fluorescence microscope. Future evidence of apoptosis/necrosis was provided by result fromannexin V-FITC/PI (fluorescein-isothiocyanate/propidium iodide staining revealed the percentage of early apoptotic, late apoptotic, necrotic and live cells in a dose- and time-dependent manner using flow cytometry. Cell cycle analysis showed G0/G1 arrest in a time-dependent manner. A western blot analysis indicated that cell death might be associated with the up-regulation of the pro-apoptotic proteins Bax PUMA. However, the anit-apotptic proteins Bcl-2, Bcl-xL, and Mcl-1 were also found to increase in a time-dependent manner. The expression of the pro-apoptotic protein Bak was not observed.

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

    Directory of Open Access Journals (Sweden)

    Shekoufeh Atashpour

    2015-07-01

    Conclusion:The CSCs were a minor population with a significantly high level of drug resistance within the HT29 cancer cells. Quercetin alone exhibited significant cytotoxic effects on HT29 cells and also increased cytoxicity of Dox in combination therapy. Altogether, our data showed that adding quercetin to Dox chemotherapy is an effective strategy for treatment of both CSCs and bulk tumor cells.

  2. Fisetin induces G2/M phase cell cycle arrest by inactivating cdc25C-cdc2 via ATM-Chk1/2 activation in human endometrial cancer cells

    Directory of Open Access Journals (Sweden)

    Zhan-Ying Wang

    2015-06-01

    Full Text Available Endometrial cancer is one of the most prevalent gynaecological malignancies where, currently available therapeutic options remain limited. Recently phytochemicals are exploited for their efficiency in cancer therapy. The present study investigates the anti-proliferative effect of fisetin, a flavonoid on human endometrial cancer cells (KLE and Hec1 A. Fisetin (20-100 µM effectively reduced the viability of Hec1 A and KLE cells and potentially altered the cell population at G2/M stage. Expression levels of the cell cycle proteins (cyclin B1, p-Cdc2, p-Cdc25C, p-Chk1, Chk2, p-ATM, cyclin B1, H2AX, p21 and p27 were analyzed. Fisetin suppressed cyclin B1 expression and caused inactiva-tion of Cdc25C and Cdc2 by increasing their phosphorylation levels and further activated ATM, Chk1 and Chk2. Increased levels of p21 and p27 were observed as well. These results suggest that fisetin induced G2/M cell cycle arrest via inactivating Cdc25c and Cdc2 through activation of ATM, Chk1 and Chk2.

  3. N-methylpurine DNA glycosylase inhibits p53-mediated cell cycle arrest and coordinates with p53 to determine sensitivity to alkylating agents

    Institute of Scientific and Technical Information of China (English)

    Shanshan Song; Guichun Xing; Lin Yuan; Jian Wang; Shan Wang; Yuxin Yin; Chunyan Tian; Fuchu He; Lingqiang Zhang

    2012-01-01

    Alkylating agents induce genome-wide base damage,which is repaired mainly by N-methylpurine DNA glycosylase (MPG).An elevated expression of MPG in certain types of tumor cells confers higher sensitivity to alkylation agents because MPG-induced apurinic/apyrimidic (AP) sites trigger more strand breaks.However,the determinant of drug sensitivity or insensitivity still remains unclear.Here,we report that the p53 status coordinates with MPG to play a pivotal role in such process.MPG expression is positive in breast,lung and colon cancers (38.7%,43.4% and 25.3%,respectively) but negative in all adjacent normal tissues.MPG directly binds to the tumor suppressor p53 and represses p53 activity in unstressed cells.The overexpression of MPG reduced,whereas depletion of MPG increased,the expression levels of pro-arrest gene downstream of p53 including p21,14-3-3σ and Gadd45 but not pro-apoptotic ones.The N-terminal region of MPG was specifically required for the interaction with the DNA binding domain of p53.Upon DNA alkylation stress,in p53 wild-type tumor cells,p53 dissociated from MPG and induced cell growth arrest.Then,AP sites were repaired efficiently,which led to insensitivity to alkylating agents.By contrast,in p53-mutated cells,the AP sites were repaired with low efficacy.To our knowledge,this is the first direct evidence to show that a DNA repair enzyme functions as a selective regulator of p53,and these findings provide new insights into the functional linkage between MPG and p53 in cancer therapy.

  4. Ingestion of an isothiocyanate metabolite from cruciferous vegetables inhibits growth of human prostate cancer cell xenografts by apoptosis and cell cycle arrest.

    Science.gov (United States)

    Chiao, Jen Wei; Wu, Hongyan; Ramaswamy, Gita; Conaway, C Clifford; Chung, Fung-Lung; Wang, Longgui; Liu, Delong

    2004-08-01

    Epidemiological surveys indicate that intake of cruciferous vegetables is inversely related to prostate cancer incidence, although the responsible dietary factors have not been identified. Our studies demonstrated that exposure of human prostate cancer cells in culture to the N-acetylcysteine (NAC) conjugate of phenethyl isothiocyanate (PEITC-NAC), the major metabolite of PEITC that is abundant in watercress, inhibited proliferation and tumorigenesis. The PEITC-NAC is known to mediate cytoprotection at initiation of carcinogenesis. The relevance of PEITC-NAC in diets on the growth of prostate tumor cells has been evaluated in immunodeficient mice with xenografted tumors of human prostate cancer PC-3 cells. The daily PEITC-NAC (8 micromol/g) supplemented diet group showed a significant reduction in tumor size in 100% of the mice during the 9-week treatment period. Tumor weight at autopsy was reduced by 50% compared with mice on the diet without PEITC-NAC (P = 0.05). Mitosis and in vivo 5-bromo-2'-deoxyuridine labeled proliferating cells were reduced in these tumors. The PEITC-NAC diet up-regulated the inhibitors of cyclin-dependent kinases p21WAF-1/Cip-1 and p27Kip1, and reduced the expression of cyclins D and E, indicating they were potential molecular targets. As a result, phosphorylated Rb was significantly decreased and the G1- to S-phase transition retarded. The treated tumors also showed a significant increase in apoptosis as determined by in situ end-labeling, and by poly ADP-ribose polymerase cleavage. This study demonstrates the first in vivo evidence of dietary PEITC-NAC inhibiting tumorigenesis of prostate cancer cells. PEITC-NAC may prevent initiation of carcinogenesis and modulate the post-initiation phase by targeting cell cycle regulators and apoptosis induction.

  5. Antitumor activity of a novel bis-aziridinylnaphthoquinone (AZ4) mediat-ing cell cycle arrest and apoptosis in non-small cell lung cancer cell line NCI-H460

    Institute of Scientific and Technical Information of China (English)

    Kou-gea SHYU; Sheng-tung HUANG; Hsien-shou KUO; Wen-pin CHENG; Yuh-ling LIN

    2007-01-01

    Aim: The cytotoxic activities of a series of bis-aziridinylnaphthoquinone, AZ1 to AZ4, on human lung carcinoma cell lines, H460, and normal lung cells fibroblast cell line, MRC-5, and the mechanisms of H460 cells induced by AZ4 were investigated. Methods: The MTT assay was used to determine the cell proliferation. Cell cycle was analysed by FACS. The activity of caspase 3, 8 and 9was determined by cell-permeable fluorogenic detection system. Western blot assay was used to evaluate the regulation of cyclin B, Cdc-2, p53, p21, and the Bcl-2 protein. Results: AZ1 to AZ4 displayed various cytotoxicity activities against H460 and MRC-5 cells. Compared to those compounds, AZ4 was with the most effective agent among the 5 tested analogues at reducing H460 cell viability with an IC50 value of 1.23 μmol/L; it also exhibited weak cytotoxicity against MRC-5 cells with an IC50 value of 12.7 μmol/L. The results show that growth arrest on the G2-M phase of H460 cells induced by AZ4 for 24 h was discovered, and this might be altered with the reduced Cdc-2 protein expression of 47% at 2.0 μmol/L AZ4, but not with cyclin B protein expression. The AZ4 treated cells were then led to apoptosis after 48 h. This was associated with the activation of apoptotic enzyme caspase 3 and mediated by caspase 8, but not caspase 9 at various concentrations of AZ4 after being cultured for 48 h and 30 h, respectively. The anti-apoptotic protein (Bcl-2)expression in H460 cells altered by 39% with downregulation, and the p53 protein by 25% with upregulation after being cultured with 2.0 μmol/LAZ4 for 48 h. In a time-dependent wanrer, the expression of the p53 and p21 proteins were increased to the maximum at 24 h, and then decreased at 48. Conclusion: AZ4 represents a novel antitumor aziridinylnaphthoquinone with therapeutic potential against the non-small cell lung cancer cells.

  6. Preferential cytotoxicity of ZnO nanoparticle towards cervical cancer cells induced by ROS-mediated apoptosis and cell cycle arrest for cancer therapy

    Science.gov (United States)

    Sirelkhatim, Amna; Mahmud, Shahrom; Seeni, Azman; Kaus, Noor Haida Mohd

    2016-08-01

    The present study aimed to synthesize multifunctional ZnO-NP samples, namely ZnO-20, ZnO-40, and ZnO-80 nm, using different approaches, to be used as efficient anticancer agents. Systematic characterizations revealed their particle sizes and demonstrated nanostructures of nanorods (ZnO-80 nm) and nanogranules (ZnO-20 and ZnO-40 nm). They exhibited significant ( p cancer cells. HeLa cell viabilities at 1 mM dose reduced to 37, 32, 15 %, by ZnO-80, ZnO-40, and ZnO-20 nm, respectively, at 48 h. However, the same dose exerted different effects of 79.6, 76, and 75 % on L929 normal cells at 48 h. Measurement of reactive oxygen species (ROS) showed a considerable ROS yields on HeLa cells by all samples with a pronounced percentage (50 %) displayed by ZnO-20 nm. Moreover, ROS-mediated apoptosis induction and blocked cell cycle progression in the S, G2/M, and G0/G1 phases significantly ( p induction was further confirmed by DNA fragmentation and Hoechst-PI costained images viewed under fluorescence microscope. Additionally, morphological changes of HeLa cells visualized under light microscope showed assortment of cell death involved shrinkage, vacuolization and apoptotic bodies' formation. Most importantly, results exposed the impact of size and morphology of ZnO samples on their toxicity to Hela cells mediated mainly by ROS production. ZnO-20 nm in disk form with its nanogranule shape and smallest particle size was the most toxic sample, followed by ZnO-40 nm and then ZnO-80 nm. An additional proposed mechanism contributed in the cell death herein was ZnO decomposition producing zinc ions (Zn2+) into the acidic cancer microenvironment due to the smaller sizes of ZnO-NPs. This mechanism has been adopted in the literatures as a size-dependent phenomenon. The emerged findings were suggested to provide new platforms in the development of therapeutics as selective agents to the fatal cervical cancer, and to benefit from the synergistic influence of size and nanostructure when

  7. A palmitoyl conjugate of insect pentapeptide Yamamarin arrests cell proliferation and respiration

    OpenAIRE

    2010-01-01

    A palmitoyl conjugate of an insect pentapeptide that occurs in diapausing insects causes a reversible cell-cycle arrest and suppresses mitochondrial respiration. This peptide compound also causes growth arrest in murine leukemic cell line expressing human gene Bcr/Abl and a farnesoyl peptide induces embryonic diapause in Bombyx mori. These results demonstrate that the insect peptide compounds can lead to the understanding of a common pathway in developmental arrest in animals and may provide ...

  8. New derivative of 2-(2,4-dihydroxyphenyl)thieno-1,3-thiazin-4-one (BChTT) elicits antiproliferative effect via p38-mediated cell cycle arrest in cancer cells.

    Science.gov (United States)

    Juszczak, Małgorzata; Walczak, Katarzyna; Matysiak, Joanna; Lemieszek, Marta K; Langner, Ewa; Karpińska, Monika M; Pożarowski, Piotr; Niewiadomy, Andrzej; Rzeski, Wojciech

    2016-03-15

    2-(2,4-Dihydroxyphenyl)thieno-1,3-thiazin-4-ones are a group of new compounds with potential anticancer activity. This type of derivatives was poorly investigated in the area of synthesis and biological activities. In the present study the antiproliferative action of the most active derivative BChTT was described. The aim of biological evaluation was to investigate the ability of the compound to inhibit cancer cell proliferation and identify mechanism involved in its action on the molecular level. BChTT inhibited the proliferation of lung cancer A549, colon cancer HT-29 and glioma C6 cells in the concentration-dependent manner. It was not toxic to normal cells including skin fibroblasts, hepatocytes and oligodendrocytes in the antiproliferative concentrations. BChTT decreased the DNA synthesis in the treated cancer cells and induced cell cycle arrest in the G0/G1 phase. Moreover, the ability of the compound to activate p38 kinase and decrease cyclin D1 expression was estimated. Participation of p38 kinase in the antiproliferative action of the compound was confirmed by the analysis of BChTT activity in the cells with the p38 silenced gene. The obtained results may suggest the ability of the tested derivative to inhibit cancer cells proliferation by induction of p38-mediated cyclin D1 downregulation.

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

    Directory of Open Access Journals (Sweden)

    Karimian H

    2014-09-01

    and the quantitative polymerase chain reaction analysis of MCF-7 cells after treatment with FALHE revealed an upregulation of Bax and a downregulation of Bcl-2 proteins. These findings proposed that FALHE suppressed the proliferation of MCF-7 cells via cell cycle arrest and the induction of apoptosis through intrinsic pathway. Keywords: Ferulago angulata, apoptosis, cancer, MCF-7, cell cycle, p21/p27