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Sample records for cell-cycle arrest activates

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

    SciTech Connect

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

    2014-03-07

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

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

    PubMed

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

    2016-06-01

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

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

    PubMed Central

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

    2014-01-01

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

  4. Gene copy number and cell cycle arrest

    NASA Astrophysics Data System (ADS)

    Ghosh, Bhaswar; Bose, Indrani

    2006-03-01

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

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

    PubMed

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

    2013-01-01

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

  6. Synchronized Cell Cycle Arrest Promotes Osteoclast Differentiation

    PubMed Central

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

    2016-01-01

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

  7. Synchronized Cell Cycle Arrest Promotes Osteoclast Differentiation.

    PubMed

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

    2016-01-01

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

  8. Impact of Mitochondria-Mediated Apoptosis in U251 Cell Cycle Arrest in G1 Stage and Caspase Activation

    PubMed Central

    Zhang, Lei; Liang, Peng; Zhang, Rui

    2015-01-01

    Background Most mitochondria-mediated apoptosis has some relevance to the cell cycle, but there is still a lack of investigations about U251 cell cycle in human brain glioma cells. In this study, we aimed to clarify the correlation of mitochondria-mediated apoptosis with the U251 cell cycle and its influence on apoptosis, through observing the impact of mitochondria-mediated apoptosis in U251cell specificity cycle arrest and Caspase activation. Material/Methods AnnexinV/PI and API were used to label the brain glioma cells for flow cytometry analysis of U251 cell apoptosis and cell cycle. RT-PCR and Western blot were performed to detect Caspase-3 and Caspase-9 activation. Results Peripheral blood in stationary phase is not sensitive to apoptosis induction, but U251 cells have obvious apoptosis. Mitochondria-mediated apoptosis mainly occurs in the G1 phase of the cell cycle. Caspase-3 and Caspase-9 mRNAs and proteins expression increased significantly after the cells were treated by mitochondrial apoptosis-related gene Bax induction. Conclusions Mitochondria-mediated apoptosis is related to the U251 cell cycle with specific G1 stage arrest. Caspase activation occurs in the process of cell apoptosis. PMID:26594875

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

    PubMed Central

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

    2014-01-01

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

  10. Piperine Causes G1 Phase Cell Cycle Arrest and Apoptosis in Melanoma Cells through Checkpoint Kinase-1 Activation

    PubMed Central

    Fofaria, Neel M.; Kim, Sung-Hoon; Srivastava, Sanjay K.

    2014-01-01

    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. PMID:24804719

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

    PubMed

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

    2012-04-01

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

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed Central

    Granier, Celine J.; Wang, Wei; Tsang, Tiffany; Steward, Ruth; Sabaawy, Hatem E.; Bhaumik, Mantu; Rabson, Arnold B.

    2014-01-01

    ABSTRACT 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. PMID:25150276

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

    PubMed

    Granier, Celine J; Wang, Wei; Tsang, Tiffany; Steward, Ruth; Sabaawy, Hatem E; Bhaumik, Mantu; Rabson, Arnold B

    2014-01-01

    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. PMID:25150276

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

    PubMed

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

    2015-01-01

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

  16. Triptolide abrogates growth of colon cancer and induces cell cycle arrest by inhibiting transcriptional activation of E2F.

    PubMed

    Oliveira, Amanda R; Beyer, Georg; Chugh, Rohit; Skube, Steven J; Majumder, Kaustav; Banerjee, Sulagna; Sangwan, Veena; Li, Lihua; Dawra, Rajinder K; Subramanian, Subbaya; Saluja, Ashok K; Dudeja, Vikas

    2015-06-01

    Despite significant progress in diagnostics and therapeutics, over 50 thousand patients die from colorectal cancer annually. Hence, there is urgent need for new lines of treatment. Triptolide, a natural compound isolated from the Chinese herb Tripterygium wilfordii, is effective against multiple cancers. We have synthesized a water soluble analog of triptolide, named Minnelide, which is currently in phase I trial against pancreatic cancer. The aims of the current study were to evaluate whether triptolide/Minnelide is effective against colorectal cancer and to elucidate the mechanism by which triptolide induces cell death in colorectal cancer. Efficacy of Minnelide was evaluated in subcutaneous xenograft and liver metastasis model of colorectal cancer. For mechanistic studies, colon cancer cell lines HCT116 and HT29 were treated with triptolide and the effect on viability, caspase activation, annexin positivity, lactate dehydrogenase release, and cell cycle progression was evaluated. Effect of triptolide on E2F transcriptional activity, mRNA levels of E2F-dependent genes, E2F1- retinoblastoma protein (Rb) binding, and proteins levels of regulator of G1-S transition was also measured. DNA binding of E2F1 was evaluated by chromatin immunoprecipitation assay. Triptolide decreased colon cancer cell viability in a dose- and time-dependent fashion. Minnelide markedly inhibited the growth of colon cancer in the xenograft and liver metastasis model of colon cancer and more than doubles the median survival of animals with liver metastases from colon cancer. Mechanistically, we demonstrate that at low concentrations triptolide induces apoptotic cell death but at higher concentrations it induces cell cycle arrest. Our data suggest that triptolide is able to induce G1 cell cycle arrest by inhibiting transcriptional activation of E2F1. Our data also show that triptolide downregulates E2F activity by potentially modulating events downstream of DNA binding. Therefore, we conclude

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

    PubMed Central

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

    2015-01-01

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

  18. Triptolide Abrogates Growth of Colon Cancer and Induces Cell Cycle Arrest by Inhibiting Transcriptional Activation of E2F

    PubMed Central

    Chugh, Rohit; Skube, Steven J; Majumder, Kaustav; Banerjee, Sulagna; Sangwan, Veena; Li, Lihua; Dawra, Rajinder; Subramanian, Subbaya; Saluja, Ashok; Dudeja, Vikas

    2016-01-01

    Background Despite significant progress in diagnostics and therapeutics, over fifty thousand patients die from colorectal cancer annually. Hence there is urgent need for new lines of treatment. Triptolide, a natural compound isolated from the Chinese herb Tripterygium wilfordii, is effective against multiple cancers. We have synthesized a water soluble analog of triptolide, named Minnelide, which is currently in phase I trial against pancreatic cancer. The aims of the current study were to evaluate whether triptolide/Minnelide is effective against colorectal cancer and to elucidate the mechanism by which triptolide induces cell death in colorectal cancer. Methods Efficacy of Minnelide was evaluated in subcutaneous xenograft and liver metastasis model of colorectal cancer. For mechanistic studies colon cancer cell lines HCT116 and HT29 were treated with triptolide and the effect on viability, caspase activation, annexin positivity, lactate dehydrogenase(LDH) release and cell cycle progression was evaluated. Effect of triptolide on E2F transcriptional activity, mRNA levels of E2F dependent genes, E2F1-Rb binding and proteins levels of regulator of G1-S transition was also measured. DNA binding of E2F1 was evaluated by chromatin immunoprecipitation assay. Results Triptolide decreased colon cancer cell viability in a dose- and time-dependent fashion. Minnelide markedly inhibited the growth of colon cancer in the xenograft and liver metastasis model of colon cancer and more than doubles the median survival of animals with liver metastases from colon cancer. Mechanistically we demonstrate that at low concentrations, triptolide induces apoptotic cell death but at higher concentrations it induces cell cycle arrest. Our data suggest that triptolide is able to induce G1 cell cycle arrest by inhibiting transcriptional activation of E2F1. Our data also show that triptolide downregulates E2F activity by potentially modulating events downstream of DNA binding. Conclusion

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

    PubMed

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

    2015-01-01

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

  20. E. adenophorum induces Cell Cycle Arrest and Apoptosis of Splenocytes through the Mitochondrial Pathway and Caspase Activation in Saanen Goats

    PubMed Central

    He, Yajun; Mo, Quan; Hu, Yanchun; Chen, Weihong; Luo, Biao; Wu, Lei; Qiao, Yan; Xu, Ruiguang; Zhou, Yancheng; Zuo, Zhicai; Deng, Junliang; He, Wei; Wei, Yahui

    2015-01-01

    The precise cytotoxicity of E. Adenophorum in relation to the cell cycle and apoptosis of splenocytes in Saanen goats remains unclear. In the present study, 16 Saanen goats were randomly divided into four groups, which were fed on 0%, 40%, 60% and 80% E. adenophorum diets. The results of TUNEL, DAPI and AO/EB staining, flow cytometry analysis and DNA fragmentation assays showed that E. adenophorum induced typical apoptotic features in splenocytes, suppressed splenocyte viability, and caused cell cycle arrest in a dose-dependent manner. However, westernblot, ELISA, qRT-PCR and caspase activity analyses showed that E. adenophoruminhibited Bcl-2 expression, promoted Bax translocation to the mitochondria, triggered the release of Cytc from the mitochondria into the cytosol, and activated caspase-9 and -3 and the subsequent cleavage of PARP. Moreover, in E. adenophorum-induced apoptosis, the protein levels of Fas, Bid, FasL and caspase-8 showed no significant changes. E. adenophorum treatment induced the collapse of ΔΨm. Moreover, these data suggested that E. adenophorum induces splenocyte apoptosis via the activation of the mitochondrial apoptosis pathway in splenocytes. These findings provide new insights into the mechanisms underlying the effects of E. adenophorum cytotoxicity on splenocytes. PMID:26527166

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

    PubMed

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

    2014-01-01

    Neferine is the major bisbenzylisoquinoline alkaloid isolated from the seed embryo of a traditional medicinal plant Nelumbo nucifera (Lotus). Epidemiological studies have revealed the therapeutic potential of lotus seed embryo. Although several mechanisms have been proposed, a clear anticancer action mechanism of neferine on lung cancer cells is still not known. Lung cancer is the most common cause of cancer death in the world, and the patients with advanced stage of nonsmall lung cancer require adjunct chemotherapy after surgical resection for the eradication of cancer cells. In this study, the effects of neferine were evaluated and characterized in A549 cells. Neferine induced apoptosis in a dose-dependent manner with the hypergeneration of reactive oxygen species, activation of MAPKs, lipid peroxidation, depletion of cellular antioxidant pool, loss of mitochondrial membrane potential, and intracellular calcium accumulation. Furthermore, neferine treatment leads to the inhibition of nuclear factor kappaB and Bcl2, upregulation of Bax and Bad, release of cytochrome C, activation of caspase cascade, and DNA fragmentation. In addition, neferine could induce p53 and its effector protein p21 and downregulation of cell cycle regulatory protein cyclin D1 thereby inducing G1 cell cycle arrest. These results suggest a novel function of neferine as an apoptosis inducer in lung cancer cells. PMID:23983146

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

    PubMed

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

    2014-05-16

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

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

    PubMed

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

    2015-01-01

    The aim of our study was to determine the effect of potential anti-tumour agent benfluron on human leukemic cells MOLT-4 and elucidate the molecular mechanisms of response of tumour cells to this chemotherapeutic agent. It has been shown that the mechanisms of action of benfluron are complex, but the molecular pathways of the cytostatic effect have remained unknown and the present study contributes to their elucidation. In this work, benfluron reduced viability of the treated cells and induced caspase-mediated apoptosis. The programmed cell death was associated with activation of caspases 8, 9 and 3/7. Moreover, exposure of cells to benfluron resulted in accumulation of the cells primarily in late S and G2/M phases. The changes in the levels of key proteins show that benfluron provoked activation of p53 and induced phosphorylation of p53 on serine 15 and serine 392. The application of benfluron led to phosphorylation of Chk1 on serine 345 and phosphorylation of Chk2 on threonine 68 in the treated cells. Higher doses of benfluron caused phosphorylation of ERK1/2 on threonine 202 and tyrosine 204, whereas JNK and p38 kinases were not activated. In conclusion, benfluron induces apoptosis, cell cycle arrest in late S and G2/M phases, and activates various signalling pathways of the DNA damage response. PMID:26441204

  4. UVA-activated 8-methoxypsoralen (PUVA) causes G2/M cell cycle arrest in Karpas 299 T-lymphoma cells.

    PubMed

    Bartosová, Jitka; Kuzelová, Katerina; Pluskalová, Michaela; Marinov, Iuri; Halada, Petr; Gasová, Zdenka

    2006-10-01

    We investigated the effect of UVA-activated 8-methoxypsoralen (PUVA) on the cell line Karpas 299 derived from anaplastic large-cell lymphoma (ALCL) expressing chimeric fusion protein nucleophosmin-anaplastic lymphoma kinase (NPM/ALK). NPM/ALK activates phosphatidylinositol 3 kinase (PI3K)/Akt pathway responsible for the cell protection from apoptosis. We found that PUVA treatment first induced G2/M cell cycle arrest resulting in a decrease in the cell proliferation rate. The mitochondrial apoptosis was triggered immediately following PUVA treatment, as we judged from the unmasking of mitochondrial membrane antigen 7A6. However, the mitochondrial membrane depolarization was not observed and caspase-3 was only slightly activated. The late apoptotic events were lacking: neither translocation of phosphatidylserine to the outer side of plasma membrane nor DNA fragmentation occurred. We revealed that PUVA enhanced the expression of peroxiredoxin, stress protein endoplasmin and galectin-3. Galectin-3 has been shown to protect mitochondrial membrane integrity and prevent cytochrome c release thereby blocking the effector stage of apoptosis. We suggest that the elevated level of this protein following PUVA treatment acts in synergy with the constitutively expressed chimeric kinase NPM/ALK to block the apoptosis. PMID:16735125

  5. Quercetin, a Natural Flavonoid Interacts with DNA, Arrests Cell Cycle and Causes Tumor Regression by Activating Mitochondrial Pathway of Apoptosis

    PubMed Central

    Srivastava, Shikha; Somasagara, Ranganatha R.; Hegde, Mahesh; Nishana, Mayilaadumveettil; Tadi, Satish Kumar; Srivastava, Mrinal; Choudhary, Bibha; Raghavan, Sathees C.

    2016-01-01

    Naturally occurring compounds are considered as attractive candidates for cancer treatment and prevention. Quercetin and ellagic acid are naturally occurring flavonoids abundantly seen in several fruits and vegetables. In the present study, we evaluate and compare antitumor efficacies of quercetin and ellagic acid in animal models and cancer cell lines in a comprehensive manner. We found that quercetin induced cytotoxicity in leukemic cells in a dose-dependent manner, while ellagic acid showed only limited toxicity. Besides leukemic cells, quercetin also induced cytotoxicity in breast cancer cells, however, its effect on normal cells was limited or none. Further, quercetin caused S phase arrest during cell cycle progression in tested cancer cells. Quercetin induced tumor regression in mice at a concentration 3-fold lower than ellagic acid. Importantly, administration of quercetin lead to ~5 fold increase in the life span in tumor bearing mice compared to that of untreated controls. Further, we found that quercetin interacts with DNA directly, and could be one of the mechanisms for inducing apoptosis in both, cancer cell lines and tumor tissues by activating the intrinsic pathway. Thus, our data suggests that quercetin can be further explored for its potential to be used in cancer therapeutics and combination therapy. PMID:27068577

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

    PubMed

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

    2014-12-01

    Ustilago maydis is a plant pathogen that requires a specific structure called infective filament to penetrate the plant tissue. Although able to grow, this filament is cell cycle arrested on the plant surface. This cell cycle arrest is released once the filament penetrates the plant tissue. The reasons and mechanisms for this cell cycle arrest are unknown. Here, we have tried to address these questions. We reached three conclusions from our studies. First, the observed cell cycle arrest is the result of the cooperation of at least two distinct mechanisms: one involving the activation of the DNA damage response (DDR) cascade; and the other relying on the transcriptional downregulation of Hsl1, a kinase that modulates the G2/M transition. Second, a sustained cell cycle arrest during the infective filament step is necessary for the virulence in U. maydis, as a strain unable to arrest the cell cycle was severely impaired in its ability to infect corn plants. Third, production of the appressorium, a structure required for plant penetration, is incompatible with an active cell cycle. The inability to infect plants by strains defective in cell cycle arrest seems to be caused by their failure to induce the appressorium formation process. In summary, our findings uncover genetic circuits to arrest the cell cycle during the growth of this fungus on the plant surface, thus allowing the penetration into plant tissue. PMID:25411209

  7. Umbelliferone exhibits anticancer activity via the induction of apoptosis and cell cycle arrest in HepG2 hepatocellular carcinoma cells.

    PubMed

    Yu, Shi-Min; Hu, Dong-Hui; Zhang, Jian-Jun

    2015-09-01

    Hepatocellular carcinoma (HCC) is a highly malignant tumor, associated with poor patient prognoses, and high rates of morbidity and mortality. To date, the therapeutic strategies available for the treatment of HCC remain limited. The present study aimed to elucidate the anticancer activity of umbelliferone, a naturally occurring coumarin derivative isolated from Ferula communis, against the HepG2 HCC cell line. A 3‑(4,5‑dimthylthaizol‑2‑yl)‑2,5, diphenyltetrazolium bromide assay was used to evaluate cell viability following umbelliferone treatment, and the effects of umbelliferone on cell cycle progression and apoptosis were evaluated using flow cytometry. The presence of morphological features characteristic of apoptosis, including cell shrinkage, membrane blebbing, nuclear condensation and apoptotic body formation, were evaluated in HepG2 cells following umbelliferone treatment. Cell cycle analysis conducted via propidium iodide (PI) staining indicated that umbelliferone treatment induced cell cycle arrest at S phase in HepG2 cells. Analysis with Annexin V and PI staining revealed that umbelliferone induced apoptotic events in HepG2 cells in a concentration‑dependant manner (0‑50 µM). Umbelliferone also induced dose‑dependant DNA fragmentation. In conclusion, umbelliferone was found to exhibit significant anticancer effects via the induction of apoptosis, cell cycle arrest and DNA fragmentation in HepG2 cancer cells. PMID:25997538

  8. DNA methylation is stable during replication and cell cycle arrest

    PubMed Central

    Vandiver, Amy R.; Idrizi, Adrian; Rizzardi, Lindsay; Feinberg, Andrew P.; Hansen, Kasper D.

    2015-01-01

    DNA methylation is an epigenetic modification with important functions in development. Large-scale loss of DNA methylation is a hallmark of cancer. Recent work has identified large genomic blocks of hypomethylation associated with cancer, EBV transformation and replicative senescence, all of which change the proportion of actively proliferating cells within the population measured. We asked if replication or cell-cycle arrest affects the global levels of methylation or leads to hypomethylated blocks as observed in other settings. We used fluorescence activated cell sorting to isolate primary dermal fibroblasts in G0, G1 and G2 based on DNA content and Ki67 staining. We additionally examined G0 cells arrested by contact inhibition for one week to determine the effects of extended arrest. We analyzed genome wide DNA methylation from sorted cells using whole genome bisulfite sequencing. This analysis demonstrated no global changes or large-scale hypomethylated blocks in any of the examined cell cycle phases, indicating that global levels of methylation are stable with replication and arrest. PMID:26648411

  9. Atmospheric particulate matter (PM10) exposure-induced cell cycle arrest and apoptosis evasion through STAT3 activation via PKCζ and Src kinases in lung cells.

    PubMed

    Reyes-Zárate, Elizabeth; Sánchez-Pérez, Yesennia; Gutiérrez-Ruiz, María Concepción; Chirino, Yolanda I; Osornio-Vargas, Álvaro Román; Morales-Bárcenas, Rocío; Souza-Arroyo, Verónica; García-Cuellar, Claudia María

    2016-07-01

    Atmospheric particulate matter with aerodynamic diameter ≤10 μm (PM10) is a risk factor for the development of lung cancer, but cellular pathways are not completely understood. STAT3 is a p21(Waf1/Cip1) transcription factor and is associated with proliferation and cell survival and is upregulated in lung cancer. PM10 exposure induces p21(Waf1/Cip1) expression, which could be related to STAT3 activation. The aims of this work were to investigate whether STAT3 was activated on lung epithelial cells after PM10 exposure and to determine whether or not STAT3 could have an impact on cell cycle distribution and cell survival. Our results showed that PM10 induced STAT3 activation through Src and PKCζ kinases, and it is partially responsible for the p21(Waf1/Cip1) induction that was also observed. Moreover, PM10 induced G1-G0 cell cycle arrest. The inhibition of STAT3 phosphorylation prevented cell cycle arrest and triggered apoptosis. These results suggest that PM10 exposure might activate a survival pathway related to STAT3 activation, similar to what has been described as part of the immune system and apoptosis evasion during tumor promotion and development. PMID:27131825

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

    PubMed

    Blagosklonny, Mikhail V

    2012-03-01

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

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

    PubMed Central

    Jia, Yong-sen; Hu, Xue-qin; Gabriella, Hegyi; Qin, Li-juan; Meggyeshazi, Nora

    2015-01-01

    Objective. The purpose of the study was to elucidate the molecular mechanism of tenacissoside H (TDH) inhibiting esophageal carcinoma infiltration and proliferation. Methods. In vitro, EC9706 cells were treated with TDH. Cells proliferation and cell cycle were assayed. PI3K and NF-κB mRNAs expression were determined by real time PCR. In vivo, model of nude mice with tumor was established. Mice were treated with TDH. Inhibition ratio of tumor volume was calculated. PCNA expression was examined. Protein expression in PI3K/Akt-NF-κB signaling pathway was determined. Results. In vitro, TDH significantly inhibited cells proliferation in a time-and-dose-dependent manner. TDH arrested the cell cycle in S phase and significantly inhibited PI3K and NF-κB mRNA expression, compared with blank controlled group (P < 0.05). In vivo, TDH strongly inhibits tumor growth and volume. PCNA expression was significantly decreased after treatment of TDH. TDH downregulated proteins expression in PI3K/Akt-NF-κB transduction cascade (P < 0.05). Conclusion. TDH inhibited esophageal carcinoma infiltration and proliferation both in vitro and in vivo. The anticancer activity has relation to arresting the cell cycle at the S phase, inhibited the PCNA expression of transplanted tumors in nude mice, and regulated the protein expression in the PI3K/Akt-NF-κB transduction cascade. PMID:26495015

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed

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

    2015-10-20

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

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

    PubMed

    Zhang, Lina; Chen, Zhenzhu; Zuo, Wenli; Zhu, Xinghu; Li, Yufu; Liu, Xinjian; Wei, Xudong

    2016-04-01

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

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

    PubMed Central

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

    2016-01-01

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

  16. Activation of nuclear PTEN by inhibition of Notch signaling induces G2/M cell cycle arrest in gastric cancer.

    PubMed

    Kim, S-J; Lee, H-W; Baek, J-H; Cho, Y-H; Kang, H G; Jeong, J S; Song, J; Park, H-S; Chun, K-H

    2016-01-14

    Mutation in PTEN has not yet been detected, but its function as a tumor suppressor is inactivated in many cancers. In this study we determined that, activated Notch signaling disables PTEN by phosphorylation and thereby contributes to gastric tumorigenesis. Notch inhibition by small interfering RNA or γ-secretase inhibitor (GSI) induced mitotic arrest and apoptosis in gastric cancer cells. Notch inhibition induced dephosphorylation in the C-terminal domain of PTEN, which led to PTEN nuclear localization. Overexpression of activated Notch1-induced phosphorylation of PTEN and reversed GSI-induced mitotic arrest. Dephosphorylated nuclear PTEN caused prometaphase arrest by interaction with the cyclin B1-CDK1 complex, resulting in their accumulation in the nucleus and subsequent apoptosis. We found a correlation between high expression levels of Notch1 and low survival rates and, similarly, between reduced nuclear PTEN expression and increasing the TNM classification of malignant tumours stages in malignant tissues from gastric cancer patients. The growth of Notch1-depleted gastric tumors was significantly retarded in xenografted mice, and in addition, PTEN deletion restored growth similar to control tumors. We also demonstrated that combination treatment with GSI and chemotherapeutic agents significantly reduced the orthotopically transplanted gastric tumors in mice without noticeable toxicity. Overall, our findings suggest that inhibition of Notch signaling can be employed as a PTEN activator, making it a potential target for gastric cancer therapy. PMID:25823029

  17. The cytotoxic activities of 7-isopentenyloxycoumarin on 5637 cells via induction of apoptosis and cell cycle arrest in G2/M stage

    PubMed Central

    2014-01-01

    Background Bladder cancer is the second common malignancy of genitourinary tract, and transitional cell carcinomas (TCCs) account for 90% of all bladder cancers. Due to acquired resistance of TCC cells to a wide range of chemotherapeutic agents, there is always a need for search on new compounds for treatment of these cancers. Coumarins represent a group of natural compounds, which some of them have exerted valuable anti-tumor activities. The current study was designed to evaluate anti-tumor properties and mechanism of action of 7-isopentenyloxycoumarin, a prenyloxycoumarin, on 5637 cells (a TCC cell line). Results MTT results revealed that the cytotoxic effects of 7-isopentenyloxycoumarin on 5637 cancerous cells were more prominent in comparison to HDF-1 normal cells. This coumarin increased the amount of chromatin condensation and DNA damage in 5637 cells by 58 and 33%, respectively. The results also indicated that it can induce apoptosis most probably via activation of caspase-3 in these cells. Moreover, propidium iodide staining revealed that 7-isopentenyloxycoumarin induced cell cycle arrest at G2/M stage, after 24 h of treatment. Conclusion Our results indicated that 7-isopentenyloxycoumarin had selective toxic effects on this bladder cancer cell line and promoted its effects by apoptosis induction and cell cycle arrest. This coumarin can be considered for further studies to reveal its exact mechanism of action and also its anti-cancer effects in vivo. PMID:24393601

  18. Anti-proliferative activity and cell cycle arrest induced by evodiamine on paclitaxel-sensitive and -resistant human ovarian cancer cells

    PubMed Central

    Zhong, Zhang-Feng; Tan, Wen; Wang, Sheng-Peng; Qiang, Wen-An; Wang, Yi-Tao

    2015-01-01

    Chemo-resistance is the main factor for poor prognosis in human ovarian epithelial cancer. Active constituents derived from Chinese medicine with anti-cancer potential might circumvent this obstacle. In our present study, evodiamine (EVO) derived from Evodia rutaecarpa (Juss.) Benth suppressed the proliferation of human epithelial ovarian cancer, A2780 and the related paclitaxel-resistant cell lines and did not cause cytotoxicity, as confirmed by the significant decline of clone formation and the representative alterations of CFDA-SE fluorescence. Meanwhile, EVO induced cell cycle arrest in a dose- and time-dependent manner. This disturbance might be mediated by the cooperation of Cyclin B1 and Cdc2, including the up-regulation of Cyclin B1, p27, and p21, and activation failure of Cdc2 and pRb. MAPK signaling pathway regulation also assisted in this process. Furthermore, chemo-sensitivity potential was enhanced as indicated in A2780/PTXR cells by the down-regulation of MDR-1 expression, accompanied by MDR-1 function suppression. Taken together, we confirmed initially that EVO exerted an anti-proliferative effect on human epithelial ovarian cancer cells, A2780/WT and A2780/PTXR, induced G2/M phase cell cycle arrest, and improved chemo-resistance. Overall, we found that EVO significantly suppressed malignant proliferation in human epithelial ovarian cancer, thus proving to be a potential anti-cancer agent in the future. PMID:26553648

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

    PubMed Central

    Chen, Aaron Yun; Qiu, Jianming

    2011-01-01

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

  20. Tetrahydrocurcumin induces G2/M cell cycle arrest and apoptosis involving p38 MAPK activation in human breast cancer cells.

    PubMed

    Kang, Ning; Wang, Miao-Miao; Wang, Ying-Hui; Zhang, Zhe-Nan; Cao, Hong-Rui; Lv, Yuan-Hao; Yang, Yang; Fan, Peng-Hui; Qiu, Feng; Gao, Xiu-Mei

    2014-05-01

    Curcumin (CUR) is a major naturally-occurring polyphenol of Curcuma species, which is commonly used as a yellow coloring and flavoring agent in foods. In recent years, it has been reported that CUR exhibits significant anti-tumor activity in vivo. However, the pharmacokinetic features of CUR have indicated poor oral bioavailability, which may be related to its extensive metabolism. The CUR metabolites might be responsible for the antitumor pharmacological effects in vivo. Tetrahydrocurcumin (THC) is one of the major metabolites of CUR. In the present study, we examined the efficacy and associated mechanism of action of THC in human breast cancer MCF-7 cells for the first time. Here, THC exhibited significant cell growth inhibition by inducing MCF-7 cells to undergo mitochondrial apoptosis and G2/M arrest. Moreover, co-treatment of MCF-7 cells with THC and p38 MAPK inhibitor, SB203580, effectively reversed the dissipation in mitochondrial membrane potential (Δψm), and blocked THC-mediated Bax up-regulation, Bcl-2 down-regulation, caspase-3 activation as well as p21 up-regulation, suggesting p38 MAPK might mediate THC-induced apoptosis and G2/M arrest. Taken together, these results indicate THC might be an active antitumor form of CUR in vivo, and it might be selected as a potentially effective agent for treatment of human breast cancer. PMID:24593988

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

    PubMed

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

    2012-01-01

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

  2. Anticancer and apoptotic activities of oleanolic acid are mediated through cell cycle arrest and disruption of mitochondrial membrane potential in HepG2 human hepatocellular carcinoma cells.

    PubMed

    Zhu, Yue-Yong; Huang, Hong-Yan; Wu, Yin-Lian

    2015-10-01

    Hepatocellular carcinoma (HCC) is an aggressive form of cancer, with high rates of morbidity and mortality, a poor prognosis and limited therapeutic options. The objective of the present study was to demonstrate the anticancer activity of oleanolic acid in HepG2 human HCC cells. Cell viability was evaluated using an MTT assay, following administration of various doses of oleanolic acid. The effect of oleanolic acid on cell cycle phase distribution and mitochondrial membrane potential was evaluated using flow cytometry with propidium iodide and rhodamine‑123 DNA‑binding cationic fluorescent dyes. Fluorescence microscopy was employed to detect morphological changes in HepG2 cells following oleanolic acid treatment. The results revealed that oleanolic acid induced a dose‑dependent, as well as time‑dependent inhibition in the growth of HepG2 cancer cells. Following acridine orange and ethidium bromide staining, treatment with various doses (0, 5, 25 and 50 µM) of oleanolic acid induced typical morphological changes associated with apoptosis, including cell shrinkage, membrane blebbing, nuclear condensation and apoptotic body formation. Cell cycle analysis revealed that oleanolic acid induced cell cycle arrest in HepG2 cells at the sub‑G1 (apoptotic) phase of the cell cycle, in a dose‑dependent manner. Staining with Annexin V‑fluorescein isothiocyanate and propidium iodide revealed that apoptosis occurred early in these cells. Oleanolic acid treatment also resulted in fragmentation of nuclear DNA in a dose‑dependent manner, producing the typical features of DNA laddering on an agarose gel. The results also demonstrated that oleanolic acid treatment resulted in a potent loss of mitochondrial membrane potential, which also occurred in a dose‑dependent manner. Therefore, oleanolic acid may be used as a therapeutic agent in the treatment of human HCC. PMID:26151733

  3. Fisetin inhibits the activities of cyclin-dependent kinases leading to cell cycle arrest in HT-29 human colon cancer cells.

    PubMed

    Lu, Xianghua; Jung, Jae in; Cho, Han Jin; Lim, Do Young; Lee, Hyun Sook; Chun, Hyang Sook; Kwon, Dae Young; Park, Jung Han Yoon

    2005-12-01

    Fisetin, a natural flavonol present in edible vegetables, fruits, and wine, was reported to exert anticarcinogenic effects. The objective of the current study was to examine the effect of fisetin on the cell cycle progression of the human colon cancer cell line HT-29. HT-29 cells were cultured in serum-free medium with 0, 20, 40, or 60 micromol/L fisetin. Fisetin dose dependently inhibited both cell growth and DNA synthesis (P < 0.05), with a 79 +/- 1% decrease in cell number observed 72 h after the addition of 60 micromol/L fisetin. Perturbed cell cycle progression from the G(1) to S phase was observed at 8 h with 60 micromol/L fisetin treatment, whereas a G(2)/M phase arrest was observed after 24 h (P < 0.05). The phosphorylation state of the retinoblastoma proteins shifted from hyperphosphorylated to hypophosphorylated in cells treated with 40 micromol/L fisetin. (P < 0.05). Fisetin decreased the activities of cyclin-dependent kinases (CDK)2 and CDK4; these effects were likely attributable to decreases in the levels of cyclin E and D1 and an increase in p21(CIP1/WAF1) levels (P < 0.05). However, fisetin also inhibited CDk4 activity in a cell-free system (P < 0.05), indicating that it may directly inhibit CDk4 activity. The protein levels of cell division cycles (CDC)2 and CDC25C and the activity of CDC2 were also decreased in fisetin-treated cells (P < 0.05). These results indicate that inhibition of cell cycle progression in HT-29 cells after treatment with fisetin can be explained, at least in part, by modification of CDK activities. PMID:16317137

  4. Cucurbitacin-I (JSI-124) activates the JNK/c-Jun signaling pathway independent of apoptosis and cell cycle arrest in B Leukemic Cells

    PubMed Central

    2011-01-01

    Background Cucurbitacin-I (JSI-124) is potent inhibitor of JAK/STAT3 signaling pathway and has anti-tumor activity in a variety of cancer including B cell leukemia. However, other molecular targets of JSI-124 beyond the JAK/STAT3 pathway are not fully understood. Methods BJAB, I-83, NALM-6 and primary CLL cells were treated with JSI-124 as indicated. Apoptosis was measured using flow cytometry for accumulation of sub-G1 phase cells (indicator of apoptosis) and Annexin V/PI staining. Cell cycle was analyzed by FACS for DNA content of G1 and G2 phases. Changes in phosphorylation and protein expression of p38, Erk1/2, JNK, c-Jun, and XIAP were detected by Western blot analysis. STAT3 and c-Jun genes were knocked out using siRNA transfection. VEGF expression was determined by mRNA and protein levels by RT-PCR and western blotting. Streptavidin Pull-Down Assay was used to determine c-Jun binding to the AP-1 DNA binding site. Results Herein, we show that JSI-124 activates c-Jun N-terminal kinase (JNK) and increases both the expression and serine phosphorylation of c-Jun protein in the B leukemic cell lines BJAB, I-83 and NALM-6. JSI-124 also activated MAPK p38 and MAPK Erk1/2 albeit at lower levels than JNK activation. Inhibition of the JNK signaling pathway failed to effect cell cycle arrest or apoptosis induced by JSI-124 but repressed JSI-124 induced c-Jun expression in these leukemia cells. The JNK pathway activation c-Jun leads to transcriptional activation of many genes. Treatment of BJAB, I-83, and NALM-6 cells with JSI-124 lead to an increase of Vascular Endothelial Growth Factor (VEGF) at both the mRNA and protein level. Knockdown of c-Jun expression and inhibition of JNK activation significantly blocked JSI-124 induced VEGF expression. Pretreatment with recombinant VEGF reduced JSI-124 induced apoptosis. Conclusions Taken together, our data demonstrates that JSI-124 activates the JNK signaling pathway independent of apoptosis and cell cycle arrest, leading to

  5. Anticancer Activity of Novel Daphnane Diterpenoids from Daphne genkwa through Cell-Cycle Arrest and Suppression of Akt/STAT/Src Signalings in Human Lung Cancer Cells.

    PubMed

    Jo, Si-Kyoung; Hong, Ji-Young; Park, Hyen Joo; Lee, Sang Kook

    2012-11-01

    Although the immense efforts have been made for cancer prevention, early diagnosis, and treatment, cancer morbidity and mortality has not been decreased during last forty years. Especially, lung cancer is top-ranked in cancer-associated human death. Therefore, effective strategy is strongly required for the management of lung cancer. In the present study, we found that novel daphnane diterpenoids, yuanhualine (YL), yuanhuahine (YH) and yuanhuagine (YG) isolated from the flower of Daphne genkwa (Thymelaeaceae), exhibited potent anti-proliferative activities against human lung A549 cells with the IC50 values of 7.0, 15.2 and 24.7 nM, respectively. Flow cytometric analysis revealed that the daphnane diterpenoids induced cell-cycle arrest in the G0/G1 as well as G2/M phase in A549 cells. The cell-cycle arrests were well correlated with the expression of checkpoint proteins including the up-regulation of cyclin-dependent kinase inhibitor p21 and p53 and down-regulation of cyclin A, cyclin B1, cyclin E, cyclin dependent kinase 4, cdc2, phosphorylation of Rb and cMyc expression. In the analysis of signal transduction molecules, the daphnane diterpenoids suppressed the activation of Akt, STAT3 and Src in human lung cancer cells. The daphnane diterpenoids also exerted the potent anti-proliferative activity against anticancer-drug resistant cancer cells including gemcitabine-resistant A549, gefitinib-, erlotinib-resistant H292 cells. Synergistic effects in the growth inhibition were also observed when yuanhualine was combined with gemcitabine, gefitinib or erlotinib in A549 cells. Taken together, these findings suggest that the novel daphnane diterpenoids might provide lead candidates for the development of therapeutic agents for human lung cancers. PMID:24009843

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

    PubMed

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

    2007-03-01

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

  7. Mechanism of antifungal activity of antimicrobial peptide APP, a cell-penetrating peptide derivative, against Candida albicans: intracellular DNA binding and cell cycle arrest.

    PubMed

    Li, Lirong; Sun, Jin; Xia, Shufang; Tian, Xu; Cheserek, Maureen Jepkorir; Le, Guowei

    2016-04-01

    We investigated the antifungal properties and anti-candidal mechanism of antimicrobial peptide APP. The minimum inhibitory concentration of APP was 8 μM against Candida albicans and Aspeogillus flavus, the concentration against Saccharomyces cerevisiae and Cryptococcus neoformans was 16 μM, while 32 μM inhibited Aspergilla niger and Trichopyton rubrum. APP caused slight depolarization (12.32 ± 0.87%) of the membrane potential of intact C. albicans cells when it exerted its anti-candidal activity and only caused 21.52 ± 0.48% C. albicans cell membrane damage. APP interacted with cell wall membrane, caused potassium efflux and nucleotide leakage. However, confocal fluorescence microscopy experiment and flow cytometry confirmed that FITC-labeled APP penetrated C. albicans cell membrane with 52.31 ± 1.88% cell-penetrating efficiency and accumulated in the cytoplasm. Then, APP interact with C. albicans genomic DNA and completely suppressed DNA migration above weight ratio (peptide/DNA) of 2, and significantly arrested cell cycles during the S-phase (S-phase cell population was 27.09 ± 0.73%, p < 0.05) after penetrating the cell membrane. Results indicated that APP kills C. albicans for efficient cell-penetrating efficiency, strong DNA-binding affinity and significant physiological changes inducing S-phase arrest in intracellular environment. PMID:26743655

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

    SciTech Connect

    Gao Jiayu; Morgan, Winston A.; Sanchez-Medina, Alberto; Corcoran, Olivia

    2011-08-01

    Despite a lack of scientific authentication, Scutellaria baicalensis is clinically used in Chinese medicine as a traditional adjuvant to chemotherapy of lung cancer. In this study, cytotoxicity assays demonstrated that crude ethanolic extracts of S. baicalensis were selectively toxic to human lung cancer cell lines A549, SK-LU-1 and SK-MES-1 compared with normal human lung fibroblasts. The active compounds baicalin, baicalein and wogonin did not exhibit such selectivity. Following exposure to the crude extracts, cellular protein expression in the cancer cell lines was assessed using 2D gel electrophoresis coupled with MALDI-TOF-MS/Protein Fingerprinting. The altered protein expression indicated that cell growth arrest and apoptosis were potential mechanisms of cytotoxicity. These observations were supported by PI staining cell cycle analysis using flow cytometry and Annexin-V apoptotic analysis by fluorescence microscopy of cancer cells treated with the crude extract and pure active compounds. Moreover, specific immunoblotting identification showed the decreased expression of cyclin A results in the S phase arrest of A549 whereas the G{sub 0}/G{sub 1} phase arrest in SK-MES-1 cells results from the decreased expression of cyclin D1. Following treatment, increased expression in the cancer cells of key proteins related to the enhancement of apoptosis was observed for p53 and Bax. These results provide further insight into the molecular mechanisms underlying the clinical use of this herb as an adjuvant to lung cancer therapy. - Research Highlights: > Scutellaria baicalensis is a clinical adjuvant to lung cancer chemotherapy in China. > Scutellaria ethanol extracts selectively toxic to A549, SK-LU-1 and SK-MES-1. > Baicalin, baicalein and wogonin were toxic to all lung cancer cell lines. > Proteomics identified increased p53 and BAX in response to Scutellaria extracts.

  9. Cell cycle arrest or survival signaling through αv integrins, activation of PKC and ERK1/2 lead to anoikis resistance of ovarian cancer spheroids.

    PubMed

    Carduner, Ludovic; Picot, Cédric R; Leroy-Dudal, Johanne; Blay, Lyvia; Kellouche, Sabrina; Carreiras, Franck

    2014-01-15

    Ovarian cancer is the most lethal gynecologic cancer mainly due to spheroids organization of cancer cells that disseminate within the peritoneal cavity. We have investigated the molecular mechanisms by which ovarian cancer spheroids resist anoikis, choosing as models the 2 well-characterized human ovarian cancer cell lines IGROV1 and SKOV3. These cell lines have the propensity to float as clusters, and were isolated from tumor tissue and ascites, respectively. To form spheroids, IGROV1 and SKOV3 ovarian adenocarcinoma cells were maintained under anchorage-independent culture conditions, in which both lines survive at least a week. A short apoptotic period prior to a survival signaling commitment was observed for IGROV1 cells whereas SKOV3 cells entered G0/G1 phase of the cell cycle. This difference in behavior was due to different signals. With regard to SKOV3 cells, activation of p38 and an increase in p130/Rb occurred once anchorage-independent culture was established. Analyses of the survival signaling pathway switched on by IGROV1 cells showed that activation of ERK1/2 was required to evade apoptosis, an effect partly dependent on PKC activation and αv integrins. αv-integrin expression is essential for survival through activation of ERK1/2 phosphorylation. The above data indicate that ovarian cancer cells can resist anoikis in the spheroid state by arrest in the cell cycle or through activation of αv-integrin-ERK-mediated survival signals. Such signaling might result in the selection of resistant cells within disseminating spheroids, favoring further relapse in ovarian cancers. PMID:24291221

  10. Cell cycle arrest in Metformin treated breast cancer cells involves activation of AMPK, downregulation of cyclin D1, and requires p27Kip1 or p21Cip1

    PubMed Central

    Zhuang, Yongxian; Miskimins, W Keith

    2008-01-01

    Background The antihyperglycemic drug metformin may have beneficial effects on the prevention and treatment of cancer. Metformin is known to activate AMP-activated protein kinase (AMPK). It has also been shown to inhibit cyclin D1 expression and proliferation of some cultured cancer cells. However, the mechanisms of action by which metformin mediates cell cycle arrest are not completely understood. Results In this study, metformin was found to inhibit proliferation of most cultured breast cancer cell lines. This was independent of estrogen receptor, HER2, or p53 status. Inhibition of cell proliferation was associated with arrest within G0/G1 phase of the cell cycle. As in previous studies, metformin treatment led to activation of (AMPK) and downregulation of cyclin D1. However, these events were not sufficient for cell cycle arrest because they were also observed in the MDA-MB-231 cell line, which is not sensitive to growth arrest by metformin. In sensitive breast cancer lines, the reduction in cyclin D1 led to release of sequestered CDK inhibitors, p27Kip1 and p21Cip1, and association of these inhibitors with cyclin E/CDK2 complexes. The metformin-resistant cell line MDA-MB-231 expresses significantly lower levels of p27Kip1 and p21Cip1 than the metformin-sensitive cell line, MCF7. When p27Kip1 or p21Cip1 were overexpressed in MDA-MB-231, the cells became sensitive to cell cycle arrest in response to metformin. Conclusion Cell cycle arrest in response to metformin requires CDK inhibitors in addition to AMPK activation and cyclin D1 downregulation. This is of interest because many cancers are associated with loss or downregulation of CDK inhibitors and the results may be relevant to the development of anti-tumor reagents that target the AMPK pathway. PMID:19046439

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed

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

    2016-01-01

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

  13. MST-312 induces G2/M cell cycle arrest and apoptosis in APL cells through inhibition of telomerase activity and suppression of NF-κB pathway.

    PubMed

    Fatemi, Ahmad; Safa, Majid; Kazemi, Ahmad

    2015-11-01

    Telomerase-targeted therapy for cancer has received great attention because telomerase is expressed in almost all cancer cells but is inactive in most normal somatic cells. This study was aimed to investigate the effects of telomerase inhibitor MST-312, a chemically modified derivative of epigallocatechin gallate (EGCG), on acute promyelocytic leukemia (APL) cells. Our results showed that MST-312 exerted a dose-dependent short-term cytotoxic effect on APL cells, with G2/M cell cycle arrest. Moreover, MST-312 induced apoptosis of APL cells in caspase-mediated manner. Telomeric repeat amplification protocol (TRAP) assay revealed significant reduction in telomerase activity of APL cells following short-term exposure to MST-312. Interestingly, MST-312-induced telomerase inhibition was coupled with suppression of NF-κB activity as evidenced by inhibition of IκBα phosphorylation and its degradation and decreased NF-κB DNA binding activity. In addition, gene expression analysis showed downregulation of genes regulated by NF-κB, such as antiapoptotic (survivin, Bcl-2, Mcl-1), proliferative (c-Myc), and telomerase-related (hTERT) genes. Importantly, MST-312 did not show any apoptotic effect in normal human peripheral blood mononuclear cells (PBMCs). In conclusion, our data suggest that dual inhibition of telomerase activity and NF-κB pathway by MST-312 represents a novel treatment strategy for APL. PMID:26022158

  14. Arabidopsis thalianaMRE11 is essential for activation of cell cycle arrest, transcriptional regulation and DNA repair upon the induction of double-stranded DNA breaks.

    PubMed

    Šamanić, I; Cvitanić, R; Simunić, J; Puizina, J

    2016-07-01

    Given the fundamental role of MRE11 in many aspects of DNA metabolism and signalling in eukaryotes, we analysed the impact of several MRE11 mutations on DNA damage response (DDR) and DNA repair in Arabidopsis thaliana. Three different atmre11 and an atatm-2 mutant lines, together with the wild type (WT), were compared using a new Arabidopsis genotoxic assay for in situ evaluation of genome integrity and DNA damage repair efficiency after double strand break (DSB) induction. The results showed that, despite the phenotypic differences and different lengths of the putative truncated AtMRE11 proteins, all three atmre11 and the atatm-2 mutant lines exhibited common hypersensitivity to bleomycin treatment, where they only slightly reduced mitotic activity, indicating a G2/M checkpoint abrogation. In contrast to the WT, which reduced the frequency of chromosomal aberrations throughout the recovery period after treatment, none of the three atmre11 and atatm-2 mutants recovered. Moreover, atmre11-3 mutants, similarly to atatm-2 mutants, failed to transcriptionally induce several DDR genes and had altered expression of the CYCB1;1::GUS protein. Nevertheless, numerous chromosomal fusions in the atmre11 mutants, observed after DNA damage induction, suggest intensive DNA repair activity. These results indicate that functional and full-length AtMRE11 is essential for activation of the cell cycle arrest, transcriptional regulation and DNA repair upon induction of DSB. PMID:27007017

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

    PubMed Central

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

    2014-01-01

    Ferulago angulata is a medicinal plant that is traditionally known for its anti-inflammatory and antiulcer properties. The present study was aimed to evaluate its anticancer activity and the possible mechanism of action using MCF-7 as an in vitro model. F. angulata leaf extracts were prepared using solvents in the order of increasing polarity. As determined by MTT assay, F. angulata leaves hexane extract (FALHE) revealed the strongest cytotoxicity against MCF-7 cells with the half maximal inhibitory concentration (IC50) value of 5.3±0.82 μg/mL. The acute toxicity study of FALHE provided evidence of the safety of the plant extract. Microscopic and flow cytometric analysis using annexin-V probe showed an induction of apoptosis in MCF-7 by FALHE. Treatment of MCF-7 cells with FALHE encouraged the intrinsic pathway of apoptosis, with cell death transducing signals that reduced the mitochondrial membrane potential with cytochrome c release from mitochondria to cytosol. The released cytochrome c triggered the activation of caspase-9. Meanwhile, the overexpression of caspase-8 suggested the involvement of an extrinsic pathway in the induced apoptosis at the late stage of treatment. Moreover, flow cytometric analysis showed that FALHE treatment significantly arrested MCF-7 cells in the G1 phase, which was associated with upregulation of p21 and p27 assessed by quantitative polymerase chain reaction. Immunofluorescence and the quantitative polymerase chain reaction analysis of MCF-7 cells after treatment with FALHE revealed an upregulation of Bax and a downregulation of Bcl-2 proteins. These findings proposed that FALHE suppressed the proliferation of MCF-7 cells via cell cycle arrest and the induction of apoptosis through intrinsic pathway. PMID:25278746

  16. Comparison of the activity of three different HSP70 inhibitors on apoptosis, cell cycle arrest, autophagy inhibition, and HSP90 inhibition

    PubMed Central

    Budina-Kolomets, Anna; Balaburski, Gregor M; Bondar, Anastasia; Beeharry, Neil; Yen, Tim; Murphy, Maureen E

    2014-01-01

    The chaperone HSP70 promotes the survival of cells exposed to many different types of stresses, and is also potently anti-apoptotic. The major stress-induced form of this protein, HSP70–1, is overexpressed in a number of human cancers, yet is negligibly expressed in normal cells. Silencing of the gene encoding HSP70–1 (HSPA1A) is cytotoxic to transformed but not normal cells. Therefore, HSP70 is considered to be a promising cancer drug target, and there has been active interest in the identification and characterization of HSP70 inhibitors for cancer therapy. Because HSP70 behaves in a relatively non-specific manner in the control of protein folding, to date there are no reliably-identified “clients” of this protein, nor is there consensus as to what the phenotypic effects of HSP70 inhibitors are on a cancer cell. Here for the first time we compare three recently-identified HSP70 inhibitors, PES-Cl, MKT-077, and Ver-155008, for their ability to impact some of the known and reported functions of this chaperone; specifically, the ability to inhibit autophagy, to influence the level of HSP90 client proteins, to induce cell cycle arrest, and to inhibit the enzymatic activity of the anaphase-promoting complex/cyclosome (APC/C). We report that all three of these compounds can inhibit autophagy and cause reduced levels of HSP90 client proteins; however, only PES-Cl can inhibit the APC/C and induce G2/M arrest. Possible reasons for these differences, and the implications for the further development of these prototype compounds as anti-cancer agents, are discussed. PMID:24100579

  17. Comparison of the activity of three different HSP70 inhibitors on apoptosis, cell cycle arrest, autophagy inhibition, and HSP90 inhibition.

    PubMed

    Budina-Kolomets, Anna; Balaburski, Gregor M; Bondar, Anastasia; Beeharry, Neil; Yen, Tim; Murphy, Maureen E

    2014-02-01

    The chaperone HSP70 promotes the survival of cells exposed to many different types of stresses, and is also potently anti-apoptotic. The major stress-induced form of this protein, HSP70-1, is overexpressed in a number of human cancers, yet is negligibly expressed in normal cells. Silencing of the gene encoding HSP70-1 (HSPA1A) is cytotoxic to transformed but not normal cells. Therefore, HSP70 is considered to be a promising cancer drug target, and there has been active interest in the identification and characterization of HSP70 inhibitors for cancer therapy. Because HSP70 behaves in a relatively non-specific manner in the control of protein folding, to date there are no reliably-identified "clients" of this protein, nor is there consensus as to what the phenotypic effects of HSP70 inhibitors are on a cancer cell. Here for the first time we compare three recently-identified HSP70 inhibitors, PES-Cl, MKT-077, and Ver-155008, for their ability to impact some of the known and reported functions of this chaperone; specifically, the ability to inhibit autophagy, to influence the level of HSP90 client proteins, to induce cell cycle arrest, and to inhibit the enzymatic activity of the anaphase-promoting complex/cyclosome (APC/C). We report that all three of these compounds can inhibit autophagy and cause reduced levels of HSP90 client proteins; however, only PES-Cl can inhibit the APC/C and induce G 2/M arrest. Possible reasons for these differences, and the implications for the further development of these prototype compounds as anti-cancer agents, are discussed. PMID:24100579

  18. Docetaxel enhances apoptosis and G2/M cell cycle arrest by suppressing mitogen-activated protein kinase signaling in human renal clear cell carcinoma.

    PubMed

    Han, T D; Shang, D H; Tian, Y

    2016-01-01

    Tremendous efforts have been made in renal cell carcinoma (RCC) patients' research; however, clinical findings in patients have been disappointing. The aims of our study were to identify better or alternative therapeutic methods that can reverse chemotherapy resistance and to enhance sensitivity to docetaxel (DOX)-based chemotherapy drugs. We evaluated the anti-proliferative effect of DOX against RCC cells. DOX was found to suppress proliferation of RCC cells under in vitro and in vivo settings. Flow cytometric analysis revealed that DOX suppressed cell growth by induction of both apoptosis and G2/M cell cycle arrest in a dose-dependent manner. Various patterns of gene expression were observed by cluster analysis. In addition, based on network analysis using the ingenuity pathway analysis software, DOX was found to suppress phosphorylation of extracellular signal-regulated kinase 1/2 and p38, suggesting that the mitogen-activated protein kinase signaling pathway plays a vital role in the anti-proliferative effect of DOX against RCC. PMID:26909952

  19. Apoptosis in male germ cells in response to cyclin A1-deficiency and cell cycle arrest.

    PubMed

    Salazar, Glicella; Liu, Dong; Liao, Ching; Batkiewicz, Leah; Arbing, Rachel; Chung, Sanny S W; Lele, Karen; Wolgemuth, Debra J

    2003-10-15

    Male mice homozygous for a mutated allele of the cyclin A1 gene (Ccna1) are sterile due to a block in cell cycle progression before the first meiotic division. Meiosis arrest in Ccna1(-/-) spermatocytes is associated with desynapsis abnormalities, lowered MPF activity, and apoptosis as evidenced by TUNEL-positive staining. With time, adult testicular tubules exhibit severe degeneration: some tubules in the older animals are almost devoid of germ cells at various stages of spermatogenesis. The mechanisms by which the cells sense the cell cycle arrest and the regulation of the decision to undergo cell death are under investigation. PMID:14555236

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

    NASA Technical Reports Server (NTRS)

    Cucinotta, Francis A.; Ren, Lei

    2004-01-01

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

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

    PubMed

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

    2016-06-01

    GATA-1, a zinc finger transcription factor, has been demonstrated to play a key role in the progression of leukemia. In this study, we investigate the effects of wogonoside, a naturally bioactive flavonoid derived from Scutellaria baicalensis Georgi, on cell growth and cell cycle in chronic myeloid leukemia (CML) cells, and uncover its underlying mechanisms. The experimental design comprised CML cell lines K562, imatinib-resistant K562 (K562r) cells, and primary CML cells, treated in vitro or in vivo, respectively, with wogonoside; growth and cell cycle were then evaluated. We found that wogonoside could induce growth inhibition and G0/G1 cell cycle arrest in both normal and K562r cells. Wogonoside promotes the expression of GATA-1 and facilitates the binding to methyl ethyl ketone (MEK) and p21 promoter, thus inhibiting MEK/extracellular signal-regulated kinase signaling and cell cycle checkpoint proteins, including CDK2, CDK4, cyclin A, and cyclin D1, and increasing p21 expression. Furthermore, in vivo studies showed that administration of wogonoside decreased CML cells and prolonged survival in NOD/SCID mice with CML cell xenografts. In conclusion, these results clearly revealed the inhibitory effect of wogonoside on the growth in CML cells and suggested that wogonoside may act as a promising drug for the treatment of imatinib-resistant CML. PMID:26104856

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

    PubMed Central

    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. PMID:25972998

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

    PubMed Central

    Yan, Shian-Jang; Li, Willis X.

    2012-01-01

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

  4. Using Drosophila larval imaginal discs to study low-dose radiation-induced cell cycle arrest.

    PubMed

    Yan, Shian-Jang; Li, Willis X

    2011-01-01

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

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

    PubMed

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

    2016-01-01

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

  6. Pneumococcal Pneumolysin Induces DNA Damage and Cell Cycle Arrest

    PubMed Central

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

    2016-01-01

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

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

    PubMed

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

    2014-01-01

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

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

    SciTech Connect

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

    2014-03-28

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

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

    PubMed

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

    2006-02-01

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

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

    PubMed Central

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

    2014-01-01

    Cell survival from the arrested state can be a cause of the cancer recurrence. Transition from the arrest state to the growth state is highly regulated by mitochondrial activity, which is related to the lipid compositions of the mitochondrial membrane. Cardiolipin is a critical phospholipid for the mitochondrial integrity and functions. We examined the changes of cardiolipin species by LC-MS in the transition between cell cycle arrest and cell reviving in HT1080 fibrosarcoma cells. We have identified 41 cardiolipin species by MS/MS and semi-quantitated them to analyze the detailed changes of cardiolipin species. The mass spectra of cardiolipin with the same carbon number form an envelope, and the C64, C66, C68, C70 C72 and C74 envelopes in HT1080 cells show a normal distribution in the full scan mass spectrum. The cardiolipin quantity in a cell decreases while entering the cell cycle arrest, but maintains at a similar level through cell survival. While cells awakening from the arrested state and preparing itself for replication, the groups with short acyl chains, such as C64, C66 and C68 show a decrease of cardiolipin percentage, but the groups with long acyl chains, such as C70 and C72 display an increase of cardiolipin percentage. Interestingly, the trends of the cardiolipin species changes during the arresting state are completely opposite to cell growing state. Our results indicate that the cardiolipin species shift from the short chain to long chain cardiolipin during the transition from cell cycle arrest to cell progression. PMID:25422939

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

    PubMed

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

    2016-01-01

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

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

    PubMed Central

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

    2016-01-01

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

  13. HIV protease inhibitor nelfinavir inhibits growth of human melanoma cells by induction of cell cycle arrest.

    PubMed

    Jiang, Wei; Mikochik, Peter J; Ra, Jin H; Lei, Hanqin; Flaherty, Keith T; Winkler, Jeffrey D; Spitz, Francis R

    2007-02-01

    HIV protease inhibitors (HIV PI) are a class of antiretroviral drugs that are designed to target the viral protease. Unexpectedly, this class of drugs is also reported to have antitumor activity. In this study, we have evaluated the in vitro activity of nelfinavir, a HIV PI, against human melanoma cells. Nelfinavir inhibits the growth of melanoma cell lines at low micromolar concentrations that are clinically attainable. Nelfinavir promotes apoptosis and arrests cell cycle at G(1) phase. Cell cycle arrest is attributed to inhibition of cyclin-dependent kinase 2 (CDK2) and concomitant dephosphorylation of retinoblastoma tumor suppressor. We further show that nelfinavir inhibits CDK2 through proteasome-dependent degradation of Cdc25A phosphatase. Our results suggest that nelfinavir is a promising candidate chemotherapeutic agent for advanced melanoma, for which novel and effective therapies are urgently needed. PMID:17283158

  14. 3,39-Diindolylmethane Ameliorates Staphylococcal Enterotoxin B–Induced Acute Lung Injury through Alterations in the Expression of MicroRNA that Target Apoptosis and Cell-Cycle Arrest in Activated T Cells.

    PubMed

    Elliott, David M; Nagarkatti, Mitzi; Nagarkatti, Prakash S

    2016-04-01

    3,39-Diindolylmethane (DIM), a natural indole found in cruciferous vegetables, has significant anti-cancer and anti-inflammatory properties. In this current study, we investigated the effects of DIM on acute lung injury (ALI) induced by exposure to staphylococcal enterotoxin B (SEB). We found that pretreatment of mice with DIM led to attenuation of SEB-induced inflammation in the lungs, vascular leak, and IFN-g secretion. Additionally, DIM could induce cell-cycle arrest and cell death in SEB-activated T cells in a concentration-dependent manner. Interestingly, microRNA (miRNA) microarray analysis uncovered an altered miRNA profile in lung-infiltrating mononuclear cells after DIM treatment of SEB-exposed mice. Moreover, computational analysis of miRNA gene targets and regulation networks indicated that DIM alters miRNA in the cell death and cell-cycle progression pathways. Specifically, DIM treatment significantly downregulated several miRNA and a correlative increase associated gene targets. Furthermore, overexpression and inhibition studies demonstrated that DIM-induced cell death, at least in part, used miR-222. Collectively, these studies demonstrate for the first time that DIM treatment attenuates SEB-induced ALI and may do so through the induction of microRNAs that promote apoptosis and cell-cycle arrest in SEB-activated T cells. PMID:26818958

  15. G1/S Cell Cycle Arrest Provides Anoikis Resistance through Erk-Mediated Bim Suppression†

    PubMed Central

    Collins, Nicole L.; Reginato, Maurico J.; Paulus, Jessica K.; Sgroi, Dennis C.; LaBaer, Joshua; Brugge, Joan S.

    2005-01-01

    Proper attachment to the extracellular matrix is essential for cell survival. Detachment from the extracellular matrix results in an apoptotic process termed anoikis. Anoikis induction in MCF-10A mammary epithelial cells is due not only to loss of survival signals following integrin disengagement, but also to consequent downregulation of epidermal growth factor (EGFR) and loss of EGFR-induced survival signals. Here we demonstrate that G1/S arrest by overexpression of the cyclin-dependent kinase inhibitors p16INK4a, p21Cip1, or p27Kip1 or by treatment with mimosine or aphidicolin confers anoikis resistance in MCF-10A cells. G1/S arrest-mediated anoikis resistance involves suppression of the BH3-only protein Bim. Furthermore, in G1/S-arrested cells, Erk phosphorylation is maintained in suspension and is necessary for Bim suppression. Following G1/S arrest, known proteins upstream of Erk, including Raf and Mek, are not activated. However, retained Erk activation under conditions in which Raf and Mek activation is lost is observed, suggesting that G1/S arrest acts at the level of Erk dephosphorylation. Thus, anoikis resistance by G1/S arrest is mediated by a mechanism involving Bim suppression through maintenance of Erk activation. These results provide a novel link between cell cycle arrest and survival, and this mechanism could contribute to the survival of nonreplicating, dormant tumor cells that avert apoptosis during early stages of metastasis. PMID:15923641

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

    PubMed

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

    2015-01-01

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

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

    PubMed Central

    Yang, Mingli; Wu, Song; Jia, Jinghua

    2011-01-01

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

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

    PubMed Central

    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. PMID:25876077

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

    PubMed

    Castanheira, Sónia; Pérez-Martín, José

    2015-01-01

    Many of the most important plant diseases are caused by fungal pathogens that form specialized cell structures to breach the leaf surface as well as to proliferate inside the plant. To initiate pathogenic development, the fungus responds to a set of inductive cues. Some of them are of extracellular nature (environmental signals) while others respond to intracellular conditions (developmental signals). These signals have to be integrated into a single response that has as a major outcome changes in the morphogenesis of the fungus. The cell cycle regulation is pivotal during these cellular differentiations, and we hypothesized that cell cycle regulation would be likely to provide control points for infection development by fungal pathogens. Although efforts have been done in various fungal systems, there is still limited information available regarding the relationship of these processes with the induction of the virulence programs. Hence, the role of fungal cell cycle regulators -which are wide conserved elements- as true virulence factors, has yet to be defined. Here we discuss the recent finding that the formation of the appressorium, a structure required for plant penetration, in the corn smut fungus Ustilago maydis seems to be incompatible with an active cell cycle and, therefore genetic circuits evolved in this fungus to arrest the cell cycle during the growth of this fungus on plant surface, before the appressorium-mediated penetration into the plant tissue. PMID:25876077

  20. Bergamottin isolated from Citrus bergamia exerts in vitro and in vivo antitumor activity in lung adenocarcinoma through the induction of apoptosis, cell cycle arrest, mitochondrial membrane potential loss and inhibition of cell migration and invasion.

    PubMed

    Wu, Hui-Juan; Wu, Hong-Bo; Zhao, Yan-Qiu; Chen, Li-Juan; Zou, Hong-Zhi

    2016-07-01

    The objective of the present study was to investigate the in vitro and in vivo anticancer properties of bergamottin, a natural furanocoumarin, against human non-small cell lung carcinoma (NSCLC) A549 cells. We also studied its effect on cell proliferation, cell cycle arrest, cell invasion, cell migration as well as cell apoptosis. Antiproliferative activity of bergamottin was estimated by the MTT assay. Phase contrast and fluorescence microscopy as well as flow cytometry using Annexin V-FITC assay were used to study induction of apoptosis by bergamottin in these cells. The effects of bergamottin on cell cycle phase distribution as well as on mitochondrial membrane potential were also demonstrated using flow cytometry. In vitro wound healing assay was used to study the effect of bergamottin on cell migration. The effects of bergamottin on tumor progression were also observed using a nude mouse model. The mice were divided into 4 groups and treated with bergamottin injected intraperitoneally. Bergamottin induced dose-dependent as well as time-dependent cytotoxic effects as well as inhibition of colony formation in the A549 cancer cells. Bergamottin also suppressed cancer cell invasion as well as cancer cell migration. Phase contrast microscopy and fluorescence microscopy revealed that bergamottin induced cell shrinkage, chromatin condensation and the cells became rounded and detached from each other. Bergamottin also induced a potent cell cycle arrest at the G2/M phase of the cell cycle. Experiments in mice showed that 25, 50 and 100 mg/kg bergamottin injection reduced the tumor weight from 1.61 g in the phosphate-buffered saline (PBS)-treated group (control) to 1.21, 0.42 and 0.15 g in the bergamottin-treated groups, respectively. The results of the present study revealed that bergamottin was able to inhibit lung cancer cell growth both in a cell model and a xenograft mouse model by inducing apoptosis, mitochondrial membrane potential loss, G2/M cell cycle

  1. 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.

    PubMed

    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. PMID:25498792

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed

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

    2009-02-01

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

  4. Adenosine induces G2/M cell-cycle arrest by inhibiting cell mitosis progression.

    PubMed

    Jia, Kun-Zhi; Tang, Bo; Yu, Lu; Cheng, Wei; Zhang, Rong; Zhang, Jian-Fa; Hua, Zi-Chun

    2010-01-01

    Cellular adenosine accumulates under stress conditions. Few papers on adenosine are concerned with its function in the cell cycle. The cell cycle is the essential mechanism by which all living things reproduce and the target machinery when cells encounter stresses, so it is necessary to examine the relationship between adenosine and the cell cycle. In the present study, adenosine was found to induce G-2/M cell-cycle arrest. Furthermore, adenosine was found to modulate the expression of some important proteins in the cell cycle, such as cyclin B and p21, and to inhibit the transition of metaphase to anaphase in mitosis. PMID:19947935

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

    SciTech Connect

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

    2012-01-13

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

  6. Severe hypoxia induces complete antifolate resistance in carcinoma cells due to cell cycle arrest

    PubMed Central

    Raz, S; Sheban, D; Gonen, N; Stark, M; Berman, B; Assaraf, Y G

    2014-01-01

    Antifolates have a crucial role in the treatment of various cancers by inhibiting key enzymes in purine and thymidylate biosynthesis. However, the frequent emergence of inherent and acquired antifolate resistance in solid tumors calls for the development of novel therapeutic strategies to overcome this chemoresistance. The core of solid tumors is highly hypoxic due to poor blood circulation, and this hypoxia is considered to be a major contributor to drug resistance. However, the cytotoxic activity of antifolates under hypoxia is poorly characterized. Here we show that under severe hypoxia, gene expression of ubiquitously expressed key enzymes and transporters in folate metabolism and nucleoside homeostasis is downregulated. We further demonstrate that carcinoma cells become completely refractory, even at sub-millimolar concentrations, to all hydrophilic and lipophilic antifolates tested. Moreover, tumor cells retained sensitivity to the proteasome inhibitor bortezomib and the topoisomerase II inhibitor doxorubicin, which are independent of cell cycle. We provide evidence that this antifolate resistance, associated with repression of folate metabolism, is a result of the inability of antifolates to induce DNA damage under hypoxia, and is attributable to a hypoxia-induced cell cycle arrest, rather than a general anti-apoptotic mechanism. Our findings suggest that solid tumors harboring a hypoxic core of cell cycle-arrested cells may display antifolate resistance while retaining sensitivity to the chemotherapeutics bortezomib and doxorubicin. This study bears important implications for the molecular basis underlying antifolate resistance under hypoxia and its rational overcoming in solid tumors. PMID:24556682

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

    PubMed

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

    2014-02-01

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

  8. Fungal Ku prevents permanent cell cycle arrest by suppressing DNA damage signaling at telomeres

    PubMed Central

    de Sena-Tomás, Carmen; Yu, Eun Young; Calzada, Arturo; Holloman, William K.; Lue, Neal F.; Pérez-Martín, José

    2015-01-01

    The Ku heterodimer serves in the initial step in repairing DNA double-strand breaks by the non-homologous end-joining pathway. Besides this key function, Ku also plays a role in other cellular processes including telomere maintenance. Inactivation of Ku can lead to DNA repair defects and telomere aberrations. In model organisms where Ku has been studied, inactivation can lead to DNA repair defects and telomere aberrations. In general Ku deficient mutants are viable, but a notable exception to this is human where Ku has been found to be essential. Here we report that similar to the situation in human Ku is required for cell proliferation in the fungus Ustilago maydis. Using conditional strains for Ku expression, we found that cells arrest permanently in G2 phase when Ku expression is turned off. Arrest results from cell cycle checkpoint activation due to persistent signaling via the DNA damage response (DDR). Our results point to the telomeres as the most likely source of the DNA damage signal. Inactivation of the DDR makes the Ku complex dispensable for proliferation in this organism. Our findings suggest that in U. maydis, unprotected telomeres arising from Ku depletion are the source of the signal that activates the DDR leading to cell cycle arrest. PMID:25653166

  9. Fungal Ku prevents permanent cell cycle arrest by suppressing DNA damage signaling at telomeres.

    PubMed

    de Sena-Tomás, Carmen; Yu, Eun Young; Calzada, Arturo; Holloman, William K; Lue, Neal F; Pérez-Martín, José

    2015-02-27

    The Ku heterodimer serves in the initial step in repairing DNA double-strand breaks by the non-homologous end-joining pathway. Besides this key function, Ku also plays a role in other cellular processes including telomere maintenance. Inactivation of Ku can lead to DNA repair defects and telomere aberrations. In model organisms where Ku has been studied, inactivation can lead to DNA repair defects and telomere aberrations. In general Ku deficient mutants are viable, but a notable exception to this is human where Ku has been found to be essential. Here we report that similar to the situation in human Ku is required for cell proliferation in the fungus Ustilago maydis. Using conditional strains for Ku expression, we found that cells arrest permanently in G2 phase when Ku expression is turned off. Arrest results from cell cycle checkpoint activation due to persistent signaling via the DNA damage response (DDR). Our results point to the telomeres as the most likely source of the DNA damage signal. Inactivation of the DDR makes the Ku complex dispensable for proliferation in this organism. Our findings suggest that in U. maydis, unprotected telomeres arising from Ku depletion are the source of the signal that activates the DDR leading to cell cycle arrest. PMID:25653166

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

    PubMed

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

    2007-06-01

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

  11. Effect of active fraction of Eriocaulon sieboldianum on human leukemia K562 cells via proliferation inhibition, cell cycle arrest and apoptosis induction.

    PubMed

    Fan, Yanhua; Lu, Hongyuan; An, Li; Wang, Changli; Zhou, Zhipeng; Feng, Fan; Ma, Hongda; Xu, Yongnan; Zhao, Qingchun

    2016-04-01

    Eriocaulon sieboldianum (Sieb. & Zucc. ex Steud.), a genus of Eriocaulon in the Eriocaulaceae family, is an edible and medicinal plant used in traditional Chinese medicine. It was processed into healthcare beverages for expelling wind-heat, protecting eyes, and reducing blood fat. Also, it has been used with other herbs as Traditional Chinese herbal compound to treat cancer as adjuvants in tumor therapy in China. However, the active fractions and precise cellular mechanisms of E. sieboldianum extract remain to be illustrated. The goal of this study was to investigate the effects of the active fraction of E. sieboldianum on the growth of K562 cells and understand the possible mechanisms of its action. Our findings suggested that the fraction E3 of E. sieboldianum could effectively inhibit the activity of Aurora kinase and induce apoptosis via blocking cell cycle, up-regulating the expression of proapoptotic proteins including p53 and Bax and reducing the expression of Bcl-2. The levels of Cytochrome C, cleaved caspase-9, cleaved caspase-3 and cleaved PARP were also found to be increased after treatment with fraction E3 of E. sieboldianum. This study could improve the development of E. sieboldianum and raise its application value in cancer adjuvant therapy. Considering it is both a dietary supplement and a traditional Chinese herbal medicine which exhibits anticancer activities, it can be developed into functional food. PMID:26923230

  12. Connexin arrests the cell cycle through cytosolic retention of an E3 ligase.

    PubMed

    Shi, Qian; Jiang, Jean X

    2016-03-01

    The gap junction proteins connexins play important roles in cell growth and differentiation; however, the underlying mechanism remains largely elusive. We recently identified a channel-independent role of connexins in cell cycle control in which connexin 50 directly interacts with S-phase kinase 2 and prevents its nuclear localization, resulting in p27/p57 protection and cell cycle arrest. PMID:27308638

  13. Induction of apoptosis and cell cycle arrest in human colorectal carcinoma by Litchi seed extract.

    PubMed

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

    2012-01-01

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

  14. Cell Division and Targeted Cell Cycle Arrest Opens and Stabilizes Basement Membrane Gaps

    PubMed Central

    Matus, David Q.; Chang, Emily; Makohon-Moore, Sasha C.; Hagedorn, Mary A.; Chi, Qiuyi; Sherwood, David R.

    2014-01-01

    Large gaps in basement membrane (BM) occur during organ remodeling and cancer cell invasion. Whether dividing cells, which temporarily reduce their attachment to BM, influence these breaches is unknown. Here we analyse uterine-vulval attachment during development across 21 species of rhabditid nematodes and find that the BM gap that forms between these organs is always bounded by a non-dividing vulval cell. Through cell cycle manipulation and live cell imaging in Caenorhabditis elegans, we show that actively dividing vulval cells facilitate enlargement of this breach by promoting BM movement. In contrast, targeted cell-cycle arrest halts BM movement and limits gap opening. Further, we demonstrate that the BM component laminin accumulates at the BM gap edge and promotes increased integrin levels in non-dividing vulval cells, stabilizing gap position. Together, these studies reveal that cell division can be used as a mechanism to regulate BM breaches, thus controlling the exchange of cells between tissues. PMID:24924309

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

    SciTech Connect

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

    2013-12-01

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

  16. Ethanol Mediates Cell Cycle Arrest and Apoptosis in SK-N-SH Neuroblastoma Cells

    PubMed Central

    Lee, Maria; Song, Byoung-Joon; Kwon, Yongil

    2014-01-01

    Background: The mechanisms of cell or organ damage by chronic alcohol consumption are still poorly understood. The present study aimed to investigate the role of the mitogen-activated protein kinases during ethanol-induced damage to SK-N-SH neuroblastoma cells. Methods: Cells were treated with ethanol and subsequently analyzed for cell morphology, viability, and DNA fragmentation. Immunoblot analysis was performed to assess various proteins levels associated with cell cycle arrest and apoptosis after ethanol exposure. Results: Ethanol induced time- and dose-dependent cell death in SK-N-SH cells and increased c-Jun N-terminal protein kinase (JNK) activity in a time- and concentration dependent manner. In contrast, p38 kinase activity increased transiently. After treatment with JNK or p38 kinase inhibitors, ethanol-induced cell death significantly reduced. Ethanol-induced cell death was accompanied by increased cytochrome c release and caspase 3 activity observed at 12 h. In contrast, the level of anti-apoptotic Bcl-2 protein did not change. Ethanol also increased the phosphorylation of p53 and p53 activation was followed by an increase in the p21 tumor suppressor protein accompanied by a gradual decrease in phospho-Rb protein. Conclusion: Our results suggest that ethanol mediates apoptosis of neuroblastoma cells by stimulating p53-related cell cycle arrest mediated through activation of the JNK-related pathway. PMID:25337571

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

    PubMed Central

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

    2013-01-01

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

  18. Combined Treatment of MCF-7 Cells with AICAR and Methotrexate, Arrests Cell Cycle and Reverses Warburg Metabolism through AMP-Activated Protein Kinase (AMPK) and FOXO1

    PubMed Central

    Fodor, Tamás; Szántó, Magdolna; Abdul-Rahman, Omar; Nagy, Lilla; Dér, Ádám; Kiss, Borbála; Bai, Peter

    2016-01-01

    Cancer cells are characterized by metabolic alterations, namely, depressed mitochondrial oxidation, enhanced glycolysis and pentose phosphate shunt flux to support rapid cell growth, which is called the Warburg effect. In our study we assessed the metabolic consequences of a joint treatment of MCF-7 breast cancer cells with AICAR, an inducer of AMP-activated kinase (AMPK) jointly with methotrexate (MTX), a folate-analog antimetabolite that blunts de novo nucleotide synthesis. MCF7 cells, a model of breast cancer cells, were resistant to the individual application of AICAR or MTX, however combined treatment of AICAR and MTX reduced cell proliferation. Prolonged joint application of AICAR and MTX induced AMPK and consequently enhanced mitochondrial oxidation and reduced the rate of glycolysis. These metabolic changes suggest an anti-Warburg rearrangement of metabolism that led to the block of the G1/S and the G2/M transition slowing down cell cycle. The slowdown of cell proliferation was abolished when mitotropic transcription factors, PGC-1α, PGC-1β or FOXO1 were silenced. In human breast cancers higher expression of AMPKα and FOXO1 extended survival. AICAR and MTX exerts similar additive antiproliferative effect on other breast cancer cell lines, such as SKBR and 4T1 cells, too. Our data not only underline the importance of Warburg metabolism in breast cancer cells but nominate the AICAR+MTX combination as a potential cytostatic regime blunting Warburg metabolism. Furthermore, we suggest the targeting of AMPK and FOXO1 to combat breast cancer. PMID:26919657

  19. Combined Treatment of MCF-7 Cells with AICAR and Methotrexate, Arrests Cell Cycle and Reverses Warburg Metabolism through AMP-Activated Protein Kinase (AMPK) and FOXO1.

    PubMed

    Fodor, Tamás; Szántó, Magdolna; Abdul-Rahman, Omar; Nagy, Lilla; Dér, Ádám; Kiss, Borbála; Bai, Peter

    2016-01-01

    Cancer cells are characterized by metabolic alterations, namely, depressed mitochondrial oxidation, enhanced glycolysis and pentose phosphate shunt flux to support rapid cell growth, which is called the Warburg effect. In our study we assessed the metabolic consequences of a joint treatment of MCF-7 breast cancer cells with AICAR, an inducer of AMP-activated kinase (AMPK) jointly with methotrexate (MTX), a folate-analog antimetabolite that blunts de novo nucleotide synthesis. MCF7 cells, a model of breast cancer cells, were resistant to the individual application of AICAR or MTX, however combined treatment of AICAR and MTX reduced cell proliferation. Prolonged joint application of AICAR and MTX induced AMPK and consequently enhanced mitochondrial oxidation and reduced the rate of glycolysis. These metabolic changes suggest an anti-Warburg rearrangement of metabolism that led to the block of the G1/S and the G2/M transition slowing down cell cycle. The slowdown of cell proliferation was abolished when mitotropic transcription factors, PGC-1α, PGC-1β or FOXO1 were silenced. In human breast cancers higher expression of AMPKα and FOXO1 extended survival. AICAR and MTX exerts similar additive antiproliferative effect on other breast cancer cell lines, such as SKBR and 4T1 cells, too. Our data not only underline the importance of Warburg metabolism in breast cancer cells but nominate the AICAR+MTX combination as a potential cytostatic regime blunting Warburg metabolism. Furthermore, we suggest the targeting of AMPK and FOXO1 to combat breast cancer. PMID:26919657

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

    PubMed Central

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

    1997-01-01

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

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

    PubMed Central

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

    2006-01-01

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

  2. MLN2238, a proteasome inhibitor, induces caspase-dependent cell death, cell cycle arrest, and potentiates the cytotoxic activity of chemotherapy agents in rituximab-chemotherapy-sensitive or rituximab-chemotherapy-resistant B-cell lymphoma preclinical models.

    PubMed

    Gu, Juan J; Hernandez-Ilizaliturri, Francisco J; Mavis, Cory; Czuczman, Natalie M; Deeb, George; Gibbs, John; Skitzki, Joseph J; Patil, Ritesh; Czuczman, Myron S

    2013-11-01

    To further develop therapeutic strategies targeting the proteasome system, we studied the antitumor activity and mechanisms of action of MLN2238, a reversible proteasome inhibitor, in preclinical lymphoma models. Experiments were conducted in rituximab-chemotherapy-sensitive cell lines, rituximab-chemotherapy-resistant cell lines (RRCL), and primary B-cell lymphoma cells. Cells were exposed to MLN2238 or caspase-dependent inhibitors, and differences in cell viability, alterations in apoptotic protein levels, effects on cell cycle, and the possibility of synergy when combined with chemotherapeutic agents were evaluated. MLN2238 showed more potent dose-dependent and time-dependent cytotoxicity and inhibition of cell proliferation in lymphoma cells than bortezomib. Our data suggest that MLN2238 can induce caspase-independent cell death in RRCL. MLN2238 (and to a much lesser degree bortezomib) reduced RRCL S phase and induced cell cycle arrest in the G2/M phase. Exposure of rituximab-chemotherapy-sensitive cell lines and RRCL to MLN2238 potentiated the cytotoxic effects of gemcitabine, doxorubicin, and paclitaxel and overcame resistance to chemotherapy in RRCL. MLN2238 is a potent proteasome inhibitor active in rituximab-chemotherapy-sensitive and rituximab-chemotherapy-resistant cell models and potentiates the antitumor activity of chemotherapy agents and has the potential of becoming an effective therapeutic agent in the treatment of therapy-resistant B-cell lymphoma. PMID:23995855

  3. Artemisinin triggers a G1 cell cycle arrest of human Ishikawa endometrial cancer cells and inhibits Cyclin Dependent Kinase-4 promoter activity and expression by disrupting NF-kB transcriptional signaling

    PubMed Central

    Tran, Kalvin Q.; Tin, Antony S.; Firestone, Gary L.

    2014-01-01

    Relatively little is known about the anti-proliferative effects of Artemisinin, a naturally occurring anti-malarial compound from Artemisia annua, or sweet wormwood, in human endometrial cancer cells. Artemisinin induced a G1 cell cycle arrest in cultured human Ishikawa endometrial cancer cells and down regulated CDK2 and CDK4 transcript and protein levels. Analysis of CDK4 promoter-luciferase reporter constructs showed that the artemisinin ablation of CDK4 gene expression was accounted for by the loss of CDK4 promoter activity. Chromatin immunoprecipitation demonstrated that artemisinin inhibited nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) subunit p65 and p50 interactions with the endogenous Ishikawa cell CDK4 promoter. Coimmunoprecipitation revealed that artemisinin disrupts endogenous p65 and p50 nuclear translocation via increased protein-protein interactions with IκB-α, an NF-κB inhibitor, and disrupts its interaction with the CDK4 promoter, leading to a loss of CDK4 gene expression. Artemisinin treatment stimulated the cellular levels of IκB-α protein without altering the level of IκB-α transcripts. Finally, expression of exogenous p65 resulted in the accumulation of this NF-κB subunit in the nucleus of artemisinin treated and untreated cells, reversed the artemisinin down-regulation of CDK4 protein expression and promoter activity and prevented the artemisinin induced G1 cell cycle arrest. Taken together, our results demonstrate that a key event in the artemisinin anti-proliferative effects in endometrial cancer cells is the transcriptional down-regulation of CDK4 expression by disruption of NF-κB interactions with the CDK4 promoter. PMID:24296733

  4. Artemisinin triggers a G1 cell cycle arrest of human Ishikawa endometrial cancer cells and inhibits cyclin-dependent kinase-4 promoter activity and expression by disrupting nuclear factor-κB transcriptional signaling.

    PubMed

    Tran, Kalvin Q; Tin, Antony S; Firestone, Gary L

    2014-03-01

    Relatively little is known about the antiproliferative effects of artemisinin, a naturally occurring antimalarial compound from Artemisia annua, or sweet wormwood, in human endometrial cancer cells. Artemisinin induced a G1 cell cycle arrest in cultured human Ishikawa endometrial cancer cells and downregulated cyclin-dependent kinase-2 (CDK2) and CDK4 transcript and protein levels. Analysis of CDK4 promoter-luciferase reporter constructs showed that the artemisinin ablation of CDK4 gene expression was accounted for by the loss of CDK4 promoter activity. Chromatin immunoprecipitation demonstrated that artemisinin inhibited nuclear factor κ-light-chain-enhancer of activated B cells (NF-κB) subunit p65 and p50 interactions with the endogenous Ishikawa cell CDK4 promoter. Coimmunoprecipitation revealed that artemisinin disrupts endogenous p65 and p50 nuclear translocation through increased protein-protein interactions with IκB-α, an NF-κB inhibitor, and disrupts its interaction with the CDK4 promoter, leading to a loss of CDK4 gene expression. Artemisinin treatment stimulated the cellular levels of IκB-α protein without altering the level of IκB-α transcripts. Finally, expression of exogenous p65 resulted in the accumulation of this NF-κB subunit in the nucleus of artemisinin-treated and artemisinin-untreated cells, reversed the artemisinin downregulation of CDK4 protein expression and promoter activity, and prevented the artemisinin-induced G1 cell cycle arrest. Taken together, our results demonstrate that a key event in the artemisinin antiproliferative effects in endometrial cancer cells is the transcriptional downregulation of CDK4 expression by disruption of NF-κB interactions with the CDK4 promoter. PMID:24296733

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

    PubMed

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

    2015-02-01

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

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

    PubMed

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

    2013-08-01

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

  7. Antiproliferative activity of the isoindigo 5'-Br in HL-60 cells is mediated by apoptosis, dysregulation of mitochondrial functions and arresting cell cycle at G0/G1 phase.

    PubMed

    Saleh, Ayman M; El-Abadelah, Mustafa M; Aziz, Mohammad Azhar; Taha, Mutasem O; Nasr, Amre; Rizvi, Syed A A

    2015-06-01

    Our new compound, 5'-Br [(E)-1-(5'-bromo-2'-oxoindolin-3'-ylidene)-6-ethyl-2,3,6,9-tetrahydro-2,9-dioxo-1H-pyrrolo[3,2-f]quinoline-8-carboxylic acid], had shown strong, selective antiproliferative activity against different cancer cell lines. Here, we aim to comprehensively characterize the mechanisms associated with its cytotoxicity in the human promyelocytic leukemia HL-60 cells. We focused at studying the involvement of apoptotic pathway and cell cycle effects. 5'-Br significantly inhibited proliferation by inducing caspase-dependent apoptosis. Involvement of caspase independent mechanism is also possible due to observed inability of z-VAD-FMK to rescue apoptotic cells. 5'-Br was found to trigger intrinsic apoptotic pathway as indicated by depolarization of the mitochondrial inner membrane, decreased level of cellular ATP, modulated expression and phosphorylation of Bcl-2 leading to loss of its association with Bax, and increased release of cytochrome c. 5'-Br treated cells were found arrested at G0/G1 phase with modulation in protein levels of cyclins, dependent kinases and their inhibitors. Expression and enzymatic activity of CDK2 and CDK4 was found inhibited. Retinoblastoma protein (Rb) phosphorylation was also inhibited whereas p21 protein levels were increased. These results suggest that the antiproliferative mechanisms of action of 5'-Br could involve apoptotic pathways, dysregulation of mitochondrial functions and disruption of cell cycle checkpoint. PMID:25790909

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

    PubMed

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

    2012-04-20

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

  9. Integrin α(V)β(3)-targeted magnetic nanohybrids with enhanced antitumor efficacy, cell cycle arrest ability, and encouraging anti-cell-migration activity.

    PubMed

    Ding, Guo-Bin; Wang, Yan; Guo, Yi; Xu, Li

    2014-10-01

    Organic/inorganic nanohybrids, which integrate advantages of the biocompatibility of organic polymers and diversified functionalities of inorganic nanoparticles, have been extensively investigated in recent years. Herein, we report the construction of arginine-glycine-aspartic acid-cysteine (RGDC) tetrapeptide functionalized and 10-hydroxycamptothecin (HCPT)-encapsulated magnetic nanohybrids (RFHEMNs) for integrin αVβ3-targeted drug delivery. The obtained RFHEMNs were near-spherical in shape with a homogeneous size about 50 nm, and exhibited a superparamagnetic behavior. In vitro drug release study showed a sustained and pH-dependent release profile. Cell viability tests revealed that RFHEMNs displayed a significant enhancement of cytotoxicity against αVβ3-overexpressing A549 cells, as compared to free HCPT and nontargeting micelles. Flow cytometry analysis indicated that this cytotoxic effect was associated with dose-dependent S phase arrest. Finally, RFHEMNs exerted encouraging anti-cell-migration activity as determined by an in vitro wound-healing assay and a transwell assay. Overall, we envision that this tumor-targeting nanoscale drug delivery system may be of great application potential in chemotherapy of primary tumor and their metastases. PMID:25207865

  10. Natural pesticide dihydrorotenone arrests human plasma cancer cells at the G0/G1 phase of the cell cycle.

    PubMed

    Xu, Xin; Zhang, Jieyu; Han, Kunkun; Zhang, Zubin; Chen, Guodong; Zhang, Jinping; Mao, Xinliang; Cao, Biyin

    2014-05-01

    Dihydrorotenone (DHR) is a natural pesticide used for farming including organic produces. We recently found that DHR induces human plasma cell apoptosis by provoking endoplasmic reticulum stress. In the present study, we found that DHR arrested human plasma cancer cells at the G0/G1 phase of the cell cycle. Mechanistical studies demonstrated that cell cycle arrest was associated with downregulated cell cycle promotors including cyclin D2, cyclin D3, cyclin-dependent kinases (CDK4, CKD6), and phosphorylated-Rb. DHR inhibited cyclin D2 transactivation, thus inhibiting its mRNA expression. In addition, DHR upregulated the cell cycle repressors p21 and p53. DHR also increased the phosphorylation level of p53, suggesting the upregulated transactivation function of p53, which was confirmed by the induction of p21, a substrate of activated p53. Moreover, DHR downregulated AKT and ERK phosphorylation, an incentive of cell cycle progression. Therefore, these results collectively demonstrated that DHR disrupts the cell cycle progress, which suggests that DHR is toxic to human plasma cells. Caution is thus suggested when handling with this agent. PMID:24615755

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

    PubMed Central

    Ferullo, Daniel J.; Lovett, Susan T.

    2008-01-01

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

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

    PubMed

    Ferullo, Daniel J; Lovett, Susan T

    2008-12-01

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

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

    PubMed Central

    Kwak, Hyun-Ho; Park, Bong-Soo

    2016-01-01

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

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

    PubMed

    Mo, H; Elson, C E

    1999-04-01

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

  15. 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.

    PubMed

    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

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed

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

    2016-01-01

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

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

    PubMed Central

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

    2015-01-01

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

  19. Induction of selective cytotoxicity and apoptosis in human T4-lymphoblastoid cell line (CEMss) by boesenbergin a isolated from boesenbergia rotunda rhizomes involves mitochondrial pathway, activation of caspase 3 and G2/M phase cell cycle arrest

    PubMed Central

    2013-01-01

    Background Boesenbergia rotunda (Roxb.) Schlecht (family zingiberaceae) is a rhizomatous herb that is distributed from north-eastern India to south-east Asia, especially in Indonesia, Thailand and Malaysia. Previous research has shown that the crude extract of this plant has cytotoxic properties. The current study examines the cytotoxic properties of boesenbergin A isolated from Boesenbergia rotunda. Methods MTT assay was used to check the cytotoxicity of boesenbergin A. The morphological assessment of apoptosis was monitored using normal and fluorescence microscopy. The early and late phase of apoptosis was investigated using annexin V and DNA laddering assays, respectively. The mitochondrial membrane potential (MMP) was assessed by fluorescence microscopy. Human apoptosis proteome profiler assays were performed to investigate the mechanism of cell death. In addition, the protein levels of Bax, Bcl2 and HSP 70 were also analyzed using western blot. Assays of caspase =-3/7, -8 and =-9 were carried out in order to test for induction during treatment. Lastly, cell cycle progression was analyzed using flow cytometry. Results Boesenbergin A was found to have the highest toxicity towards CEMss cancer cells (IC50 = 8 μg/ml). The morphology of CEMss cells after treatment showed evidence of apoptosis that included blebbing and chromatin condensation. The annexin V assay revealed that early apoptosis is induced after treatment. The DNA laddering assay confirmed that DNA fragmentation had occurred during late apoptosis. The cell cycle analysis indicated that boesenbergin A was able to induce G2/M phase arrest in CEMss cells. The activity of caspases -3/7, -8 and -9 was increased after treatment which indicates both intrinsic and extrinsic pathways are induced during apoptosis. The involvement of mitochondria was established by increased mitochondrial membrane potential and up and down regulation of Bcl2 and Bax proteins as well as HSP70. Conclusion In conclusion, the

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

    PubMed

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

    2016-01-01

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

  1. Transcription factor-pathway co-expression analysis reveals cooperation between SP1 and ESR1 on dysregulating cell cycle arrest in non-hyperdiploid multiple myeloma

    PubMed Central

    Wang, Xujun; Yan, Zhenyu; Fulciniti, Mariateresa; Li, Yingxiang; Gkotzamanidou, Maria; Amin, Samir B; Shah, Parantu K; Zhang, Yong

    2014-01-01

    Multiple myeloma is a hematological cancer of plasma B-cells and remains incurable. Two major subtypes of myeloma, hyperdiploid (HMM) and non-hyperdiploid myeloma (NHMM), have distinct chromosomal alterations and different survival outcomes. Transcription factors (TrFs) have been implicated in myeloma oncogenesis but their dysregulation in myeloma subtypes are less studied. Here we develop a TrF-pathway co-expression analysis to identify altered co-expression between two sample types. We apply the method to the two myeloma subtypes and the cell cycle arrest pathway, which is significantly differentially expressed between the two subtypes. We find that TrFs MYC, NF-κB and HOXA9 have significantly lower co-expression with cell cycle arrest in HMM, co-occurring with their over-activation in HMM. In contrast, TrFs ESR1, SP1 and E2F1 have significantly lower co-expression with cell cycle arrest in NHMM. SP1 ChIP targets are enriched by cell cycle arrest genes. These results motivate a cooperation model of ESR1 and SP1 in regulating cell cycle arrest, and a hypothesis that their over-activation in NHMM disrupts proper regulation of cell cycle arrest. Co-targeting ESR1 and SP1 shows a synergistic effect on inhibiting myeloma proliferation in NHMM cell lines. Therefore, studying TrF-pathway co-expression dysregulation in human cancers facilitates forming novel hypotheses towards clinical utility. PMID:23925045

  2. Cell Cycle Arrest in G2/M Promotes Early Steps of Infection by Human Immunodeficiency Virus

    PubMed Central

    Groschel, Bettina; Bushman, Frederic

    2005-01-01

    We have identified four small molecules that boost transduction of cells by human immunodeficiency virus (HIV) and investigated their mechanism of action. These molecules include etoposide and camptothecin, which induce DNA damage by inhibiting religation of cleaved topoisomerase-DNA complexes, taxol, which interferes with the function of microtubules, and aphidicolin, which inhibits DNA polymerases. All four compounds arrest the cell cycle at G2/M, though in addition high concentrations of aphidicolin arrest in G1. We find that early events of HIV replication, including synthesis of late reverse transcription products, two-long terminal repeat circles, and integrated proviruses, were increased after treatment of cells with concentrations of each compound that arrested in G2/M. Stimulation was seen for both transformed cell lines (293T and HeLa cells) and primary cells (IMR90 lung fibroblasts). Arrest in G1 with high concentrations of aphidicolin boosted transduction, though not much as with lower concentrations that arrested in G2/M. Arrest of IMR90 cells in G1 by serum starvation and contact inhibition reduced transduction. Previously, the proteasome inhibitor MG132 was reported to increase HIV infection—here we investigated the effects of combinations of the cell cycle inhibitors with MG132 and obtained data suggesting that MG132 may also boost transduction by causing G2/M cell cycle arrest. These data document that cell cycle arrest in G2/M boosts the early steps of HIV infection and suggests methods for increasing transduction with HIV-based vectors. PMID:15827184

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

    PubMed Central

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

    2014-01-01

    Cloves (Syzygium aromaticum) have been used as a traditional Chinese medicinal herb for thousands of years. Cloves possess antiseptic, antibacterial, antifungal, and antiviral properties, but their potential anticancer activity remains unknown. In this study, we investigated the in vitro and in vivo antitumor effects and biological mechanisms of ethyl acetate extract of cloves (EAEC) and the potential bioactive components responsible for its antitumor activity. The effects of EAEC on cell growth, cell cycle distribution, and apoptosis were investigated using human cancer cell lines. The molecular changes associated with the effects of EAEC were analyzed by Western blot and (qRT)-PCR analysis. The in vivo effect of EAEC and its bioactive component was investigated using the HT-29 tumor xenograft model. We identified oleanolic acid (OA) as one of the components of EAEC responsible for its antitumor activity. Both EAEC and OA display cytotoxicity against several human cancer cell lines. Interestingly, EAEC was superior to OA and the chemotherapeutic agent 5-fluorouracil at suppressing growth of colon tumor xenografts. EAEC promoted G0/G1 cell cycle arrest and induced apoptosis in a dose-dependent manner. Treatment with EAEC and OA selectively increased protein expression of p21WAF1/Cip1 and γ-H2AX and downregulated expression of cell cycle-regulated proteins. Moreover, many of these changes were at the mRNA level, suggesting transcriptional regulation by EAEC treatment. Our results demonstrate that clove extract may represent a novel therapeutic herb for the treatment of colorectal cancer, and OA appears to be one of the bioactive components. PMID:24854101

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

    NASA Astrophysics Data System (ADS)

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

    2016-05-01

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

  5. Citral inhibits cell proliferation and induces apoptosis and cell cycle arrest in MCF-7 cells.

    PubMed

    Chaouki, Wahid; Leger, David Y; Liagre, Bertrand; Beneytout, Jean-Louis; Hmamouchi, Mohamed

    2009-10-01

    Many natural components of plants extract are studied for their beneficial effects on health and particularly on carcinogenesis chemoprevention. In this study, we investigated the effect of citral (3,7-dimethyl-2,6-octadienal), a key component of essential oils extracted from several herbal plants, on the proliferation rate, cell cycle distribution, and apoptosis of the human breast cancer cell line MCF-7. The effects of this compound were also tested on cyclo-oxygenase activity. Citral treatment caused inhibition of MCF-7 cell growth (IC(50)-48 h: 18 x 10(-5)m), with a cycle arrest in G(2)/M phase and apoptosis induction. Moreover, we observed a decrease in prostaglandin E(2) synthesis 48 h after citral treatment. These findings suggest that citral has a potential chemopreventive effect. PMID:19656204

  6. RBP-J-interacting and tubulin-associated protein induces apoptosis and cell cycle arrest in human hepatocellular carcinoma by activating the p53–Fbxw7 pathway

    SciTech Connect

    Wang, Haihe; Yang, Zhanchun; Liu, Chunbo; Huang, Shishun; Wang, Hongzhi; Chen, Yingli; Chen, Guofu

    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.

  7. Isoalantolactone Inhibits UM-SCC-10A Cell Growth via Cell Cycle Arrest and Apoptosis Induction

    PubMed Central

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

    2013-01-01

    Isoalantolactone is a sesquiterpene lactone compound isolated from the roots of Inula helenium L. Previous studies have demonstrated that isoalantolactone possesses antifungal, anti-bacterial, anti-helminthic and anti-proliferative properties in a variety of cells, but there are no studies concerning its effects on head and neck squamous cell carcinoma (HNSCC). In the present study, an MTT assay demonstrated that isoalantolactone has anti-proliferative activity against the HNSCC cell line (UM-SCC-10A). Immunostaining identified that this compound induced UM-SCC-10A cell apoptosis but not necrosis. To explain the molecular mechanisms underlying its effects, flow cytometry and western blot analysis showed that the apoptosis was associated with cell cycle arrest during the G1 phase, up-regulation of p53 and p21, and down-regulation of cyclin D. Furthermore, our results revealed that induction of apoptosis through a mitochondrial pathway led to up-regulation of pro-apoptotic protein expression (Bax), down-regulation of anti-apoptotic protein expression (Bcl-2), mitochondrial release of cytochrome c (Cyto c), reduction of mitochondrial membrane potential (MMP) and activation of caspase-3 (Casp-3). Involvement of the caspase apoptosis pathway was confirmed using caspase inhibitor Z-VAD-FMK pretreatment. Together, our findings suggest that isoalantolactone induced caspase-dependent apoptosis via a mitochondrial pathway and was associated with cell cycle arrest in the G1 phase in UM-SCC-10A cells. Therefore, isoalantolactone may become a potential drug for treating HNSCC. PMID:24098753

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed Central

    Kellum, John A.; Chawla, Lakhmir S.

    2016-01-01

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

  11. Src kinase inhibitors induce apoptosis and mediate cell cycle arrest in lymphoma cells.

    PubMed

    Nowak, Daniel; Boehrer, Simone; Hochmuth, Simone; Trepohl, Bettina; Hofmann, Wencke; Hoelzer, Dieter; Hofmann, Wolf-Karsten; Mitrou, Paris S; Ruthardt, Martin; Chow, Kai Uwe

    2007-10-01

    Src kinases are involved in multiple cellular contexts such as proliferation, adhesion, tumor invasiveness, angiogenesis, cell cycle control and apoptosis. We here demonstrate that three newly developed dual selective Src/Abl kinase inhibitors (SrcK-I) (AZM559756, AZD0530 and AZD0424) are able to induce apoptosis and cell cycle arrest in BCR-ABL, c-KIT and platelet-derived growth factor-negative lymphoma cell lines. Treatment of DOHH-2, WSU-NHL, Raji, Karpas-299, HUT78 and Jurkat cells with SrcK-I revealed that the tested substances were effective on these parameters in the cell lines DOHH-2 and WSU-NHL, whereas the other tested cell lines remained unaffected. Phosphorylation of Lyn and in particular Lck were affected most heavily by treatment with the SrcK-I. Extrinsic as well as intrinsic apoptosis pathways were activated and elicited unique expressional patterns of apoptosis-relevant proteins such as downregulation of survivin, Bcl-XL and c-FLIP. Protein levels of c-abl were downregulated and Akt phosphorylation was decreased by treatment with SrcK-I. Basal expression levels of c-Myc were notably lower in sensitive cell lines as compared with nonsensitive cell lines, possibly providing an explanation for sensitivity versus resistance against these novel substances. This study provides the first basis for establishing novel SrcK-I as weapons in the arsenal against lymphoma cells. PMID:17704648

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

    PubMed Central

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

    2009-01-01

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

  13. Dual CDK4/CDK6 Inhibition Induces Cell Cycle Arrest and Senescence in Neuroblastoma

    PubMed Central

    Rader, JulieAnn; Russell, Mike R.; Hart, Lori S.; Nakazawa, Michael S.; Belcastro, Lili T.; Martinez, Daniel; Li, Yimei; Carpenter, Erica L.; Attiyeh, Edward F.; Diskin, Sharon J.; Kim, Sunkyu; Parasuraman, Sudha; Caponigro, Giordano; Schnepp, Robert W.; Wood, Andrew C.; Pawel, Bruce; Cole, Kristina A.; Maris, John M.

    2013-01-01

    Purpose Neuroblastoma is a pediatric cancer that continues to exact significant morbidity and mortality. Recently, a number of cell cycle proteins, particularly those within the Cyclin D/CDK4/CDK6/RB network, have been shown to exert oncogenic roles in neuroblastoma, suggesting that their therapeutic exploitation might improve patient outcomes. Experimental Procedures We evaluated the effect of dual CDK4/CDK6 inhibition on neuroblastoma viability using LEE011, a highly specific CDK4/6 inhibitor. Results Treatment with LEE011 significantly reduced proliferation in 12 of 17 human neuroblastoma-derived cell lines by inducing cytostasis at nanomolar concentrations (mean IC50 = 307 ± 68 nM in sensitive lines). LEE011 caused cell cycle arrest and cellular senescence that was attributed to dose-dependent decreases in phosphorylated RB and FOXM1, respectively. In addition, responsiveness of neuroblastoma xenografts to LEE011 translated to the in vivo setting in that there was a direct correlation of in vitro IC50 values with degree of subcutaneous xenograft growth delay. While our data indicate that neuroblastomas sensitive to LEE011 were more likely to contain genomic amplification of MYCN (p = 0.01), the identification of additional clinically accessible biomarkers is of high importance. Conclusions Taken together, our data show that LEE011 is active in a large subset of neuroblastoma cell line and xenograft models, and supports the clinical development of this CDK4/6 inhibitor as a therapy for patients with this disease. PMID:24045179

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

    NASA Astrophysics Data System (ADS)

    Liang, Liming; Bi, Wenxiang; Tian, Yuanyuan

    2016-05-01

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

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed

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

    2016-01-01

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

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

    PubMed

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

    2015-01-01

    Two new xanthones, cowaxanthones G (1) and H (2), and 23 known analogues were isolated from an acetone extract of the leaves of Garcinia cowa. The isolated compounds were evaluated for cytotoxicity against three cancer cell lines and immortalized HL7702 normal liver cells, whereby compounds 1, 5, 8, and 15-17 exhibited significant cytotoxicity. Cell cycle analysis using flow cytometry showed that 5 induced cell cycle arrest at the S phase in a dose-dependent manner, 1 and 16 at the G2/M phase, and 17 at the G1 phase, while 16 and 17 induced apoptosis. Moreover, autophagy analysis by GFP-LC3 puncta formation and western blotting suggested that 17 induced autophagy. Taken together, our results suggest that these xanthones possess anticancer activities targeting cell cycle, apoptosis, and autophagy signaling pathways. PMID:26102071

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

    PubMed

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

    2016-09-01

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

  19. 6-Shogaol induces cell cycle arrest and apoptosis in human hepatoma cells through pleiotropic mechanisms.

    PubMed

    Wu, Jung-Ju; Omar, Hany A; Lee, Ying-Ray; Teng, Yen-Ni; Chen, Pin-Shern; Chen, Yu-Chung; Huang, Hsiao-Shan; Lee, Kuan-Han; Hung, Jui-Hsiang

    2015-09-01

    Shogaols are a group of the active constituents of ginger that have been identified to have various biological activities. The aim of the current study was to investigate the antitumor activity of 6-shogaol in hepatocellular carcinoma (HCC) and the possible involvement of reactive oxygen species as a putative mechanism of action. HCC cell lines, HepG2 and Huh-7, were used to study the in vitro anti-cancer activity of 6-shogaol via the application of various molecular biology techniques. Results showed that 6-shogaol effectively inhibited the cell viability, caused cell cycle arrest at G2/M phase and induced apoptosis in HCC cells as indicated by MTT assay, DAPI nuclear staining, annexin V assay, cell cycle analysis, and activation of caspase-3. Western blot analysis revealed the ability of 6-shogaol to target cancer survival signaling pathways mediated by mitogen-activated protein kinase (MAPK), 5' AMP-activated protein kinase (AMPK) and Akt. In addition, 6-Shogaol induced alteration of cyclin proteins expression and caused cleavage of protein kinase C delta. Furthermore, 6-Shogaol was able to induce the production of reactive oxygen species and endoplasmic reticulum (ER) stress-associated proteins and the consequent activation of autophagy in HepG2 cells. Taken together, the current study highlights evidences that 6-shogaol induces apoptosis, modulates cyclins expression and targets cancer survival signaling pathways in HCC cell lines, at least in part, via the production of reactive oxygen species. These findings support 6-shogaol's clinical promise as a potential candidate for HCC therapy. PMID:26101062

  20. Carnosol, a dietary diterpene, displays growth inhibitory effects in human prostate cancer PC3 cells leading to G2-phase cell cycle arrest and targets the 5'-AMP-activated protein kinase (AMPK) pathway

    PubMed Central

    Johnson, Jeremy J.; Syed, Deeba N.; Heren, Chenelle R.; Suh, Yewseok; Adhami, Vaqar M.; Mukhtar, Hasan

    2010-01-01

    Purpose The anti-cancer effect of carnosol was investigated in human prostate cancer PC3 cells. Methods Biochemical analysis and protein array data of carnosol treated PC3 cells were analyzed. Results We evaluated carnosol for its potential anti-cancer properties in the PC3 cells. Using an MTT assay we found that carnosol (10 – 70 µM) decreases cell viability in a time and dose dependent manner. Next, we evaluated the effect of carnosol (20–60 uM) effect using flow cytometry as well as biochemical analysis and found induction of G2-phase cell cycle arrest. To establish a more precise mechanism, we performed a protein array that evaluated 638 proteins involved in cell signaling pathways. The protein array identified 5'-AMP-activated protein kinase (AMPK), a serine/threonine protein kinase involved in the regulation of cellular energy balance as a potential target. Further downstream effects consistent with cancer inhibition included the modulation of the mTOR/HSP70S6k/4E-BP1 pathway. Additionally, we found that carnosol targeted the PI3K/Akt pathway in a dose dependent manner. Conclusions These results suggest that carnosol targets multiple signaling pathways that include the AMPK pathway. The ability of carnosol to inhibit prostate cancer in vitro suggests carnosol may be a novel agent for the management of PCa. PMID:18286356

  1. Hydrogen peroxide inhibits transforming growth factor-β1-induced cell cycle arrest by promoting Smad3 linker phosphorylation through activation of Akt-ERK1/2-linked signaling pathway

    SciTech Connect

    Choi, Jiyeon; Park, Seong Ji; Jo, Eun Ji; Lee, Hui-Young; Hong, Suntaek; Kim, Seong-Jin; Kim, Byung-Chul

    2013-06-14

    Highlights: •H{sub 2}O{sub 2} inhibits TGF-β1-induced cell cycle arrest. •H{sub 2}O{sub 2} induces Smad3 linker phosphorylation through Akt-ERK1/2 pathway. •H{sub 2}O{sub 2}-mediated suppression of TGF-β signal requires Smad3 linker phosphorylation. •This is a first report about interplay between H{sub 2}O{sub 2} and growth inhibition pathway. -- Abstract: Hydrogen peroxide (H{sub 2}O{sub 2}) functions as a second messenger in growth factor receptor-mediated intracellular signaling cascade and is tumorigenic by virtue of its ability to promote cell proliferation; however, the mechanisms underlying the growth stimulatory action of H{sub 2}O{sub 2} are less understood. Here we report an important mechanism for antagonistic effects of H{sub 2}O{sub 2} on growth inhibitory response to transforming growth factor-β1 (TGF-β1). In Mv1Lu and HepG2 cells, pretreatment of H{sub 2}O{sub 2} (0.05–0.2 mM) completely blocked TGF-β1-mediated induction of p15{sup INK4B} expression and increase of its promoter activity. Interestingly, H{sub 2}O{sub 2} selectively suppressed the transcriptional activation potential of Smad3, not Smad2, in the absence of effects on TGF-β1-induced phosphorylation of the COOH-tail SSXS motif of Smad3 and its nuclear translocation. Mechanism studies showed that H{sub 2}O{sub 2} increases the phosphorylation of Smad3 at the middle linker region in a concentration- and time-dependent manner and this effect is mediated by activation of extracellular signal-activated kinase 1/2 through Akt. Furthermore, expression of a mutant Smad3 in which linker phosphorylation sites were ablated significantly abrogated the inhibitory effects of H{sub 2}O{sub 2} on TGF-β1-induced increase of p15{sup INK4B}-Luc reporter activity and blockade of cell cycle progression from G1 to S phase. These findings for the first time define H{sub 2}O{sub 2} as a signaling molecule that modulate Smad3 linker phosphorylation and its transcriptional activity, thus providing

  2. Zerumbone, a Sesquiterpene, Controls Proliferation and Induces Cell Cycle Arrest in Human Laryngeal Carcinoma Cell Line Hep-2.

    PubMed

    Jegannathan, Srimathi Devi; Arul, Santhosh; Dayalan, Haripriya

    2016-07-01

    Zerumbone (ZER), a sesquiterpene found in Zingiber zerumbet Smith, has been shown to possess antiproliferative, anticancer, antioxidant, and anti-inflammatory activity against various types of human carcinoma. The molecular mechanism by which ZER mediates its activity against many cancer types is revealed by many studies. Upregulation of proapoptotic molecules and suppression of antiapoptotic gene expression are few of the mechanisms by which ZER mediates its effect. The present study is focused on investigating the effect of ZER on proliferation of laryngeal carcinoma cells (Hep-2). MTT assay results showed that ZER (0.01-100 μM) induced death of Hep-2 cells in a concentration-dependent manner; significant suppression of proliferation of Hep-2 cells was seen with a IC50 value of 15 µM. ZER at a concentration of 15 and 30 μM for 48 h showed early signs of apoptosis as evidenced by confocal microscopy imaging. Flow cytometry studies showed that ZER induced cell cycle arrest. ZER arrested Hep-2 proliferation at S and G2/M phases of cell cycle. In conclusion, these results indicate that ZER has antiproliferative effect and arrests cell cycle in Hep-2 cells in vitro. This could be a potential anticancer drug against laryngeal carcinoma. PMID:27045964

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

    PubMed

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

    2008-11-01

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

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

    PubMed Central

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

    2010-01-01

    Functional somatostatin receptors (SSTRs) are lost in human pancreatic cancer. Transfection of SSTR-1 inhibited pancreatic cancer cell proliferation in vitro. We hypothesize that stable transfection of SSTR-1 may inhibit pancreatic cancer growth in vivo possibly through cell cycle arrest. In this study, we examined the expression of SSTR-1 mRNA in human pancreatic cancer tissue specimens, and investigated the effect of SSTR-1 overexpression on cell proliferation, cell cycle, and tumor growth in in a subcutaneous nude mouse model. We found that SSTR-1 mRNA was downregulated in the majority of pancreatic cancer tissue specimens. Transfection of SSTR-1 caused cell cycle arrest at the G0/G1 growth phase, with a corresponding decline of cells in the S (mitotic) phase. The overexpression of SSTR-1 significantly inhibited subcutaneous tumor size by 71% and 43% (n=5, p<0.05, t-test), and inhibited tumor weight by 69% and 47%, (n=5, p<0.05, t-test), in Panc-SSTR-1 and MIA-SSTR-1 groups, respectively, indicating the potent inhibitory effect of SSTR-1 on pancreatic cancer growth. Our data demonstrate that overexpression of SSTR-1 significantly inhibits pancreatic cancer growth possibly through cell cycle arrest. This study suggests that gene therapy with SSTR-1 may be a potential adjuvant treatment for pancreatic cancer. PMID:18823376

  5. Lycopene and beta-carotene induce cell-cycle arrest and apoptosis in human breast cancer cell lines.

    PubMed

    Gloria, Nathalie Fonseca; Soares, Nathalia; Brand, Camila; Oliveira, Felipe Leite; Borojevic, Radovan; Teodoro, Anderson Junger

    2014-03-01

    Lycopene and beta-carotene are carotenoids widely distributed in fruits and vegetables, with potential anticancer activity. Epidemiological trials rarely provide evidence for the mechanisms of action of these compounds, and their biological effects at different times of treatment are still unclear. The aim of the present study was to determine the effect of carotenoids on the cell cycle and cell viability in human breast cancer cell lines. Human breast cell lines were treated with carotenoids (0.5-10 μM) for 48 and 96 h. Cell viability was monitored using the MTT method (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide; thiazolyl blue). The cell cycle was analyzed by flow cytometry, and apoptotic cells were identified by annexin/propidium iodide (PI) biomarkers. Our data showed a significant decrease in the number of viable breast cancer cells on treatment with carotenoids. Carotenoids also promoted cell-cycle arrest followed by decreased cell viability in the majority of cell lines after 96 h, compared to controls. Furthermore, an increase in apoptosis was observed in cell lines when cells were treated with carotenoids. Our findings show the capacity of lycopene and beta-carotene to inhibit cell proliferation, arrest the cell cycle in different phases, and increase apoptosis. These findings indicate that the effect was cell type-dependent and that carotenoids are potential agents for biological interference with cancer. PMID:24596385

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

    PubMed Central

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

    2015-01-01

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

  7. Formononetin suppresses the proliferation of human non-small cell lung cancer through induction of cell cycle arrest and apoptosis.

    PubMed

    Yang, Yi; Zhao, Yi; Ai, Xinghao; Cheng, Baijun; Lu, Shun

    2014-01-01

    Formononetin is a novel herbal isoflavonoid isolated from Astragalus membranaceus and possesses antitumorigenic properties. In the present study, we investigated the anti-proliferative effects of formononetin on human non-small cell lung cancer (NSCLC), and further elucidated the molecular mechanism underlying the anti-tumor property. MTT assay showed that formononetin treatment significantly inhibited the proliferation of two NSCLC cell lines including A549 and NCI-H23 in a time- and dose-dependent manner. Flow cytometric analysis demonstrated that formononetin induced G1-phase cell cycle arrest and promoted cell apoptosis in NSCLC cells. On the molecular level, we observed that exposure to formononetin altered the expression levels of cell cycle arrest-associated proteins p21, cyclin A and cyclin D1. Meanwhile, the apoptosis-related proteins cleaved caspase-3, bax and bcl-2 were also changed following treatment with formononetin. In addition, the expression level of p53 was dose-dependently upregulated after administration with formononetin. We also found that formononetin treatment increased the phosphorylation of p53 at Ser15 and Ser20 and enhances its transcriptional activity in a dose-dependent manner. Collectively, these results demonstrated that formononetin might be a potential chemopreventive drug for lung cancer therapy through induction of cell cycle arrest and apoptosis in NSCLC cells. PMID:25674209

  8. MDA-7 results in downregulation of AKT concomitant with apoptosis and cell cycle arrest in breast cancer cells

    PubMed Central

    Valero, V; Wingate, H; Chada, S; Liu, Y; Palalon, F; Mills, G; Keyomarsi, K; Hunt, KK

    2013-01-01

    The melanoma differentiation-associated gene-7 (mda-7) is a known mediator of apoptosis in cancer cells but not in normal cells. We hypothesized that MDA-7 interferes with the prosurvival signaling pathways that are commonly altered in cancer cells to induce growth arrest and apoptosis. We also identified the cell signaling pathways that are antagonized by MDA-7 leading to apoptosis. Using an adenoviral expression system, mda-7 was introduced into the breast cancer cell lines SKBr3, MCF-7 and MDA-MB-468, each with a different estrogen receptor (ER) and HER-2 receptor status. Downstream targets of MDA-7 were assessed by reverse phase protein array analysis, western blot analysis and immunofluorescence confocal microscopy. Our results show that MDA-7-induced apoptosis was mediated by caspases in all cell lines tested. However, MDA-7 modulates additional pathways in SKBr3 (HER-2 positive) and MCF-7 (ER positive) cells including downregulation of AKT-GSK3β and upregulation of cyclin-dependent kinase inhibitors in the nucleus. This leads to cell cycle arrest in addition to apoptosis. In conclusion, MDA-7 abrogates tumor-promoting pathways including the activation of caspase-dependent signaling pathways ultimately leading to apoptosis. In addition, depending on the phenotype of the breast cancer cell, MDA-7 modulates cell cycle regulating pathways to mediate cell cycle arrest. PMID:21546925

  9. Two ZNF509 (ZBTB49) isoforms induce cell-cycle arrest by activating transcription of p21/CDKN1A and RB upon exposure to genotoxic stress

    PubMed Central

    Jeon, Bu-Nam; Kim, Min-Kyeong; Yoon, Jae-Hyeon; Kim, Min-Young; An, Haemin; Noh, Hee-Jin; Choi, Won-Il; Koh, Dong-In; Hur, Man-Wook

    2014-01-01

    ZNF509 is unique among POK family proteins in that four isoforms are generated by alternative splicing. Short ZNF509 (ZNF509S1, -S2 and -S3) isoforms contain one or two out of the seven zinc-fingers contained in long ZNF509 (ZNF509L). Here, we investigated the functions of ZNF509 isoforms in response to DNA damage, showing isoforms to be induced by p53. Intriguingly, to inhibit proliferation of HCT116 and HEK293 cells, we found that ZNF509L activates p21/CDKN1A transcription, while ZNF509S1 induces RB. ZNF509L binds to the p21/CDKN1A promoter either alone or by interacting with MIZ-1 to recruit the co-activator p300 to activate p21/CDKN1A transcription. In contrast, ZNF509S1 binds to the distal RB promoter to interact and interfere with the MIZF repressor, resulting in derepression and transcription of RB. Immunohistochemical analysis revealed that ZNF509 is highly expressed in normal epithelial cells, but was completely repressed in tumor tissues of the colon, lung and skin, indicating a possible role as a tumor suppressor. PMID:25245946

  10. In vitro and in vivo anti-tumor activity of CoQ0 against melanoma cells: inhibition of metastasis and induction of cell-cycle arrest and apoptosis through modulation of Wnt/β-catenin signaling pathways

    PubMed Central

    Hseu, You-Cheng; Thiyagarajan, Varadharajan; Tsou, Hsiao-Tung; Lin, Kai-Yuan; Chen, Hui-Jye; Lin, Chung-Ming; Liao, Jiuun-Wang; Yang, Hsin-Ling

    2016-01-01

    Coenzyme Q0 (CoQ0, 2,3-dimethoxy-5-methyl-1,4-benzoquinone), a novel quinone derivative, has been shown to modulate cellular redox balance. However, effect of this compound on melanoma remains unclear. This study examined the in vitro or in vivo anti-tumor, apoptosis, and anti-metastasis activities of CoQ0 (0-20 μM) through inhibition of Wnt/β-catenin signaling pathway. CoQ0 exhibits a significant cytotoxic effect on melanoma cell lines (B16F10, B16F1, and A2058), while causing little toxicity toward normal (HaCaT) cells. The suppression of β-catenin was seen with CoQ0 administration accompanied by a decrease in the expression of Wnt/β-catenin transcriptional target c-myc, cyclin D1, and survivin through GSK3β-independent pathway. We found that CoQ0 treatment caused G1 cell-cycle arrest by reducing the levels of cyclin E and CDK4. Furthermore, CoQ0 treatment induced apoptosis through caspase-9/-3 activation, PARP degradation, Bcl-2/Bax dysregulation, and p53 expression. Notably, non- or sub-cytotoxic concentrations of CoQ0 markedly inhibited migration and invasion, accompanied by the down-regulation of MMP-2 and -9, and up-regulation of TIMP-1 and -2 expressions in highly metastatic B16F10 cells. Furthermore, the in vivo study results revealed that CoQ0 treatment inhibited the tumor growth in B16F10 xenografted nude mice. Histological analysis and western blotting confirmed that CoQ0 significantly decreased the xenografted tumor progression as demonstrated by induction of apoptosis, suppression of β-catenin, and inhibition of cell cycle-, apoptotic-, and metastatic-regulatory proteins. The data suggest that CoQ0 unveils a novel mechanism by down-regulating Wnt/β-catenin pathways and could be used as a potential lead compound for melanoma chemotherapy. PMID:26968952

  11. Interleukin-24 mediates apoptosis in human B-cells through early activation of cell cycle arrest followed by late induction of the mitochondrial apoptosis pathway.

    PubMed

    Hadife, Nader; Nemos, Christophe; Frippiat, Jean-Pol; Hamadé, Tala; Perrot, Aurore; Dalloul, Ali

    2013-03-01

    Interleukin (IL)-24 has death-promoting effects on various proliferating cells including B-cells from chronic lymphocytic leukemia (CLL) and germinal center B-cells, but its molecular mechanisms are poorly understood. Using a B-cell differentiation model and mRNA profiling, we found that recombinant (r)IL-24 stimulated genes of the mitochondrial apoptotic pathway (Bax, Bid, Casp8, COX6C, COX7B) after 36 h, whereas the transcription of genes involved in DNA replication and metabolism was inhibited within 6 h. Unexpectedly, insulin-like growth factor 1 (IGF1), a hormone known to promote cell growth, was stimulated by IL-24. Activated B-cells express receptor for IGF1, to which they become sensitized and undergo apoptosis, a mechanism similar in this respect to IL-24-induced cell death. Furthermore, inhibition of the IGF1 pathway reversed the effects of IL-24. IL-24-mediated apoptosis was also antagonized by pifithrin-alpha, an inhibitor of p53 transactivation. Altogether, these results disclose sequential molecular signals generated by IL-24 in activated B-cells. PMID:22860893

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

    SciTech Connect

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

    2006-03-24

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

  13. Crataegus azarolus Leaves Induce Antiproliferative Activity, Cell Cycle Arrest, and Apoptosis in Human HT-29 and HCT-116 Colorectal Cancer Cells.

    PubMed

    Mustapha, Nadia; Pinon, Aline; Limami, Youness; Simon, Alain; Ghedira, Kamel; Hennebelle, Thierry; Chekir-Ghedira, Leila

    2016-05-01

    Limited success has been achieved in extending the survival of patients with metastatic colorectal cancer (CRC). There is a strong need for novel agents in the treatment and prevention of CRC. Therefore, in the present study we evaluated the antiproliferative and pro-apoptotic potential of Crataegus azarolus ethyl acetate extract in HCT-116 and HT-29 human colorectal cancer cell lines. Moreover, we attempted to investigate the signaling pathways that should be involved in its cytotoxic effect. The Crataegus azarolus ethyl acetate extract-induced growth inhibitory effect was associated with DNA fragmentation, sub-G1 peak, loss of mitochondrial potential, and poly (ADP-ribose) polymerase (PARP) cleavage. In addition, ethyl acetate extract of Crataegus azarolus induced the cleavage of caspase-8. It has no effect on steady-state levels of total Bcl-2 protein. Whereas Bax levels decreased significantly in a dose-dependent manner in both tested cell lines. Taken together, these findings confirm the involvement of the extrinsic pathway of apoptosis. The apoptotic cell death induced by ethyl acetate extract of Crataegus azarolus was accompanied by an enhancement of the p21 expression but not through p53 activation in human colorectal cancer cells. The above-mentioned data provide insight into the molecular mechanisms of Crataegus azarolus ethyl acetate extract-induced apoptosis in CRC. Therefore, this compound should be a potential anticancer agent for the treatment of CRC. PMID:26495895

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

    PubMed

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

    2015-10-01

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

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

    PubMed

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

    2013-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

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

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

    PubMed Central

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

    2015-01-01

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

  18. Oridonin inhibits tumor growth in glioma by inducing cell cycle arrest and apoptosis.

    PubMed

    Zhang, X-H; Liu, Y-X; Jia, M; Han, J-S; Zhao, M; Ji, S-P; Li, A-M

    2014-01-01

    Glioma is the most common malignant intracranial tumors. Despite newly developed therapies, these treatments mainly target oncogenic signals, and unfortunately, fail to provide enough survival benefit in both human patients and mouse xenograft models, especially the first-generation therapies. Oridonin is purified from the Chinese herb Rabdosia rubescens and considered to exert extensive anti-cancer effects on human tumorigenesis. In this study, we systemically investigated the role of Oridonin in tumor growth and the underlying mechanisms in human glioma. We found that Oridonin inhibited cell proliferations in a dose- and time-dependent manner in both glioma U87 and U251 cells. Moreover, these anti-cancer effects were also confirmed in a mouse model bearing glioma. Furthermore, cell cycle arrest in S phase was observed in Oridonin-mediated growth inhibition by flow cytometry. Cell cycle arrest in S phase led to eventual cell apoptosis, as revealed by Hoechst 33342 staining and annexin V/PI double-staining. The cell apoptosis might be accomplished through a mitochondrial manner. In all, we were the first to our knowledge to report that Oridonin could exert anti-cancer effects on tumor growth in human glioma by inducing cell cycle arrest and eventual cell apoptosis. The identification of Oridonin as a critical mediator of glioma growth may potentiate Oridonin as a novel therapeutic strategies in glioma treatments. PMID:25553351

  19. Gracillin induces apoptosis in HL60 human leukemic cell line via oxidative stress and cell cycle arrest of G1.

    PubMed

    Chen, Chuan-Rong; Zhang, Jun; Wu, Ke-Wei; Liu, Peng-Ying; Wang, Shang-Jun; Chen, Dong-Yun; Ji, Zhao-Ning

    2015-03-01

    Gracillin, a kind of steroidal saponin isolated from the root bark of wild yam Dioscorea nipponica has been reported to exert antitumor activity. In the present study, we investigated the anticancer activity of gracillin against HL60 cells, and evaluated the possible mechanism involved in its antineoplastic action. The cell proliferation was evaluated by cell counting Kit-8 (CCK-8) assay, gracillin inhibited the growth of HL60 cells in a time- and concentration-dependent manner. Flow cytometry was used to analyze the cell cycle distribution whereas Annexin V-FITC/PI flow cytometry analysis was carried out to confirm apoptosis induced by gracillin, Our results demonstrated that gracillin could induce cell cycle arrest of G1 and apoptosis in HL60 cells. Furthermore, based on the biochemical methods, induction of oxidative stress by gracillin was indicated by increased the content of malondialdehyde (MDA), and decreased superoxide dismutase (SOD) activity. In addition, real time-PCR verified the expression of apoptosis-related genes, the mRNA level of Bcl-2 was decreased dramatically, while Bax was remarkably increased by gracillin. Taken together, gracillin could induce cell cycle arrest, oxidative stress, and apoptosis in HL60 cells, and has the potential to be developed as an antitumor agent. PMID:25980181

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

    PubMed

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

    2015-01-01

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

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

    PubMed Central

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

    2009-01-01

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

  2. Pirarubicin inhibits multidrug-resistant osteosarcoma cell proliferation through induction of G2/M phase cell cycle arrest

    PubMed Central

    Zheng, Shui-er; Xiong, Sang; Lin, Feng; Qiao, Guang-lei; Feng, Tao; Shen, Zan; Min, Da-liu; Zhang, Chun-ling; Yao, Yang

    2012-01-01

    Aim: Pirarubicin (THP) is recently found to be effective in treating patients with advanced, relapsed or recurrent high-grade osteosarcoma. In this study, the effects of THP on the multidrug-resistant (MDR) osteosarcoma cells were assessed, and the underlying mechanisms for the disruption of cell cycle kinetics by THP were explored. Methods: Human osteosarcoma cell line MG63 and human MDR osteosarcoma cell line MG63/DOX were tested. The cytotoxicity of drugs was examined using a cell proliferation assay with the Cell Counting Kit-8 (CCK-8). The distribution of cells across the cell cycle was determined with flow cytometry. The expression of cell cycle-regulated genes cyclin B1 and Cdc2 (CDK1), and the phosphorylated Cdc2 and Cdc25C was examined using Western blot analyses. Results: MG63/DOX cells were highly resistant to doxorubicin (ADM) and gemcitabine (GEM), but were sensitive or lowly resistant to THP, methotrexate (MTX) and cisplatin (DDP). Treatment of MG63/DOX cells with THP (200–1000 ng/mL) inhibited the cell proliferation in time- and concentration-dependent manners. THP (50–500 ng/mL) induced MG63/DOX cell cycle arrest at the G2/M phase in time- and concentration-dependent manners. Furthermore, the treatment of MG63/DOX cells with THP (200–1000 ng/mL) downregulated cyclin B1 expression, and decreased the phosphorylated Cdc2 at Thr161. Conversely, the treatment increased the phosphorylated Cdc2 at Thr14/Tyr15 and Cdc25C at Ser216, which led to a decrease in Cdc2-cyclin B1 activity. Conclusion: The cytotoxicity of THP to MG63/DOX cells may be in part due to its ability to arrest cell cycle progression at the G2/M phase, which supports the use of THP for managing patients with MDR osteosarcoma. PMID:22580740

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

    PubMed Central

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

    2015-01-01

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

  4. Sulforaphane Induces Cell Cycle Arrest and Apoptosis in Acute Lymphoblastic Leukemia Cells

    PubMed Central

    Suppipat, Koramit; Park, Chun Shik; Shen, Ye; Zhu, Xiao; Lacorazza, H. Daniel

    2012-01-01

    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 p21CIP1/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. PMID:23251470

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

    PubMed Central

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

    2014-01-01

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

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

    PubMed

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

    2015-10-01

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

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed

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

    2014-07-01

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

  9. End-of-life cell cycle arrest contributes to stochasticity of yeast replicative aging.

    PubMed

    Delaney, Joe R; Chou, Annie; Olsen, Brady; Carr, Daniel; Murakami, Christopher; Ahmed, Umema; Sim, Sylvia; An, Elroy H; Castanza, Anthony S; Fletcher, Marissa; Higgins, Sean; Holmberg, Mollie; Hui, Jessica; Jelic, Monika; Jeong, Ki-Soo; Kim, Jin R; Klum, Shannon; Liao, Eric; Lin, Michael S; Lo, Winston; Miller, Hillary; Moller, Richard; Peng, Zhao J; Pollard, Tom; Pradeep, Prarthana; Pruett, Dillon; Rai, Dilreet; Ros, Vanessa; Schleit, Jennifer; Schuster, Alex; Singh, Minnie; Spector, Benjamin L; Sutphin, George L; Wang, Adrienne M; Wasko, Brian M; Vander Wende, Helen; Kennedy, Brian K; Kaeberlein, Matt

    2013-05-01

    There is growing evidence that stochastic events play an important role in determining individual longevity. Studies in model organisms have demonstrated that genetically identical populations maintained under apparently equivalent environmental conditions display individual variation in life span that can be modeled by the Gompertz-Makeham law of mortality. Here, we report that within genetically identical haploid and diploid wild-type populations, shorter-lived cells tend to arrest in a budded state, while cells that arrest in an unbudded state are significantly longer-lived. This relationship is particularly notable in diploid BY4743 cells, where mother cells that arrest in a budded state have a shorter mean life span (25.6 vs. 35.6) and larger coefficient of variance with respect to individual life span (0.42 vs. 0.32) than cells that arrest in an unbudded state. Mutations that cause genomic instability tend to shorten life span and increase the proportion of the population that arrest in a budded state. These observations suggest that randomly occurring damage may contribute to stochasticity during replicative aging by causing a subset of the population to terminally arrest prematurely in the S or G2 phase of the cell cycle. PMID:23336757

  10. End-of-life cell cycle arrest contributes to stochasticity of yeast replicative aging

    PubMed Central

    Delaney, Joe R.; Chou, Annie; Olsen, Brady; Carr, Daniel; Murakami, Christopher; Ahmed, Umema; Sim, Sylvia; An, Elroy H.; Castanza, Anthony S.; Fletcher, Marissa; Higgins, Sean; Holmberg, Mollie; Hui, Jessica; Jelic, Monika; Jeong, Ki-Soo; Kim, Jin R.; Klum, Shannon; Liao, Eric; Lin, Michael S.; Lo, Winston; Miller, Hillary; Moller, Richard; Peng, Zhao J.; Pollard, Tom; Pradeep, Prarthana; Pruett, Dillon; Rai, Dilreet; Ros, Vanessa; Schleit, Jennifer; Schuster, Alex; Singh, Minnie; Spector, Benjamin L.; Sutphin, George L.; Wang, Adrienne M.; Wasko, Brian M.; Wende, Helen Vander; Kennedy, Brian K.; Kaeberlein, Matt

    2013-01-01

    There is growing evidence that stochastic events play an important role in determining individual longevity. Studies in model organisms have demonstrated that genetically identical populations maintained under apparently equivalent environmental conditions display individual variation in lifespan that can be modeled by the Gompertz-Makeham law of mortality. Here we report that within genetically identical haploid and diploid wild type populations, shorter-lived cells tend to arrest in a budded state, while cells that arrest in an unbudded state are significantly longer-lived. This relationship is particularly notable in diploid BY4743 cells, where mother cells that arrest in a budded state have a shorter mean lifespan (25.6 vs. 35.6) and larger coefficient of variance with respect to individual lifespan (0.42 vs. 0.32) than cells that arrest in an unbudded state. Mutations that cause genomic instability tend to shorten lifespan and increase the proportion of the population that arrest in a budded state. These observations suggest that randomly occurring damage may contribute to stochasticity during replicative aging by causing a subset of the population to terminally arrest prematurely in the S or G2 phase of the cell cycle. PMID:23336757

  11. Fusarochromanone Induces G1 Cell Cycle Arrest and Apoptosis in COS7 and HEK293 Cells

    PubMed Central

    Gu, Ying; Chen, Xin; Shang, Chaowei; Singh, Karnika; Barzegar, Mansoureh; Mahdavian, Elahe; Salvatore, Brian A.; Jiang, Shanxiang; Huang, Shile

    2014-01-01

    Fusarochromanone (FC101), a mycotoxin produced by the fungus Fusarium equiseti, is frequently observed in the contaminated grains and feedstuffs, which is toxic to animals and humans. However, the underlying molecular mechanism remains to be defined. In this study, we found that FC101 inhibited cell proliferation and induced cell death in COS7 and HEK293 cells in a concentration-dependent manner. Flow cytometric analysis showed that FC101 induced G1 cell cycle arrest and apoptosis in the cells. Concurrently, FC101 downregulated protein expression of cyclin D1, cyclin-dependent kinases (CDK4 and CDK6), and Cdc25A, and upregulated expression of the CDK inhibitors (p21Cip1 and p27Kip1), resulting in hypophosphorylation of Rb. FC101 also inhibited protein expression of Bcl-2, Bcl-xL, Mcl-1 and survivin, and induced expression of BAD, leading to activation of caspase 3 and cleavage of PARP, indicating caspase-dependent apoptosis. However, Z-VAD-FMK, a pan-caspase inhibitor, only partially prevented FC101-induced cell death, implying that FC101 may induce cell death through both caspase-dependent and -independent mechanisms. Our results support the notion that FC101 executes its toxicity at least by inhibiting cell proliferation and inducing cell death. PMID:25384025

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

    PubMed

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

    2013-12-01

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

  13. Retama monosperma n-hexane extract induces cell cycle arrest and extrinsic pathway-dependent apoptosis in Jurkat cells

    PubMed Central

    2014-01-01

    Background Retama monosperma L. (Boiss.) or Genista monosperma L. (Lam.), locally named as “R’tam”, is an annual and spontaneous plant belonging to the Fabaceae family. In Morocco, Retama genus is located in desert regions and across the Middle Atlas and it has been widely used in traditional medicine in many countries. In this study, we show that Retama monosperma hexane extract presents significant anti-leukemic effects against human Jurkat cells. Methods Human Jurkat cells, together with other cell lines were screened with different concentrations of Retama monosperma hexane extract at different time intervals. Growth inhibition was determined using luminescent-based viability assays. Cell cycle arrest and apoptosis were measured by flow cytometry analysis. Combined caspase 3 and 7 activities were measured using luminometric caspase assays and immunoblots were performed to analyze expression of relevant pro- and anti-apoptotic proteins. GC-MS were used to determine the chemical constituents of the active extract. Results Retama monosperma hexane extract (Rm-HE) showed significant cytotoxicity against Jurkat cells, whereas it proved to be essentially ineffective against both normal mouse fibroblasts (NIH3T3) and normal lymphocytes (TK-6). Cytometric analysis indicated that Rm-HE promoted cell cycle arrest and apoptosis induction accompanied by DNA damage induction indicated by an increase in p-H2A.X levels. Rm-HE induced apoptosis was partially JNK-dependent and characterized by an increase in Fas-L levels together with activation of caspases 8, 3, 7 and 9, whereas neither the pro-apoptotic nor anti-apoptotic mitochondrial membrane proteins analyzed were significantly altered. Chemical identification analysis indicated that α-linolenic acid, campesterol, stigmasterol and sitosterol were the major bioactive components within the extract. Conclusions Our data suggest that bioactive compounds present in Rm-HE show significant anti leukemic activity inducing

  14. SOX10 ablation arrests the cell cycle, induces senescence and suppresses melanomagenesis

    PubMed Central

    Cronin, Julia C.; Watkins-Chow, Dawn E.; Incao, Art; Hasskamp, Joanne H.; Schönewolf, Nicola; Aoude, Lauren G.; Hayward, Nicholas K.; Bastian, Boris C.; Dummer, Reinhard; Loftus, Stacie K.; Pavan, William J.

    2013-01-01

    The transcription factor SOX10 is essential for survival and proper differentiation of neural crest cell lineages, where it plays an important role in the generation and maintenance of melanocytes. SOX10 is also highly expressed in melanoma tumors, but a role in disease progression has not been established. Here we report that melanoma tumor cell lines require wild-type SOX10 expression for proliferation, and SOX10 haploinsufficiency reduces melanoma initiation in the metabotropic glutamate receptor 1 (Grm1Tg) transgenic mouse model. Stable SOX10 knockdown in human melanoma cells arrested cell growth, altered cellular morphology, and induced senescence. Melanoma cells with stable loss of SOX10 were arrested in the G1 phase of the cell cycle, with reduced expression in the melanocyte determining factor MITF, elevated expression of p21WAF1 and p27KIP2, hypophosphorylated RB and reduced levels of its binding partner E2F1. Since cell cycle dysregulation is a core event in neoplastic transformation, the role for SOX10 in maintaining cell cycle control in melanocytes suggests a rational new direction for targeted treatment or prevention of melanoma. PMID:23913827

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

    SciTech Connect

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

    2008-07-18

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

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

    PubMed Central

    2014-01-01

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

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

    SciTech Connect

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

    2010-07-16

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

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

    PubMed

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

    2014-08-01

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

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

    PubMed

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

    2012-01-01

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

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

    PubMed

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

    2007-09-15

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

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

    PubMed Central

    HONG, JING-FANG; SONG, YING-FANG; LIU, ZHENG; ZHENG, ZHAO-CONG; CHEN, HONG-JIE; WANG, SHOU-SEN

    2016-01-01

    The aim of the present study was to investigate the in vitro and in vivo anticancer and apoptotic effects of taraxerol acetate in U87 human glioblastoma cells. The effects on cell cycle phase distribution, cell cycle-associated proteins, autophagy, DNA fragmentation and cell migration were assessed. Cell viability was determined using the MTT assay, and phase contrast and fluorescence microscopy was utilized to determine the viability and apoptotic morphological features of the U87 cells. Flow cytometry using propidium iodide and Annexin V-fluorescein isothiocyanate demonstrated the effect of taraxerol acetate on the cell cycle phase distribution and apoptosis induction. Western blot analysis was performed to investigate the effect of the taraxerol acetate on cell cycle-associated proteins and autophagy-linked LC3B-II proteins. The results demonstrated that taraxerol acetate induced dose- and time-dependent cytotoxic effects in the U87 cells. Apoptotic induction following taraxerol acetate treatment was observed and the percentage of apoptotic cells increased from 7.3% in the control cells, to 16.1, 44.1 and 76.7% in the 10, 50 and 150 µM taraxerol acetate-treated cells, respectively. Furthermore, taraxerol acetate treatment led to sub-G1 cell cycle arrest with a corresponding decrease in the number of S-phase cells. DNA fragments were observed as a result of the gel electrophoresis experiment following taraxerol acetate treatment. To investigate the inhibitory effects of taraxerol acetate on the migration of U87 cell, a wound healing assay was conducted. The number of cells that migrated to the scratched area decreased significantly following treatment with taraxerol acetate. In addition, taraxerol acetate inhibited tumor growth in a mouse xenograft model. Administration of 0.25 and 0.75 µg/g taraxerol acetate reduced the tumor weight from 1.2 g in the phosphate-buffered saline (PBS)-treated group (control) to 0.81 and 0.42 g, respectively. Similarly, 0.25 and 0

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

    PubMed

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

    2016-07-01

    Tangeretin (TANG), present in peel of citrus fruits, has been shown to various medicinal properties such as chemopreventive and neuroprotective. However, the chemopreventive effect of TANG on glioblastoma cells has not been examined. The present study was designed to explore the anticancer potential of TANG in glioblastoma cells and to investigate the related mechanism. Human glioblastoma U-87MG and LN-18 cells were treated with 45μM concentration of TANG and cell growth was measured by MTT assay. The cell cycle distribution and cell death were measured by flow cytometry. The expression of cell cycle and apoptosis related genes were analyzed by quantitative RT-PCR and western blot. The cells treated with TANG were significantly increased cell growth suppression and cell death effects than vehicle treated cells. Further, TANG treatment increases G2/M arrest and apoptosis by modulating PTEN and cell-cycle regulated genes such as cyclin-D and cdc-2 mRNA and protein expressions. Moreover, the ability of TANG to decrease cell growth and to induce cell death was compromised when PTEN was knockdown by siRNA. Taken together, the chemopreventive effect of TANG is associated with regulation of cell-cycle and apoptosis in glioblastoma, thereby attenuating glioblastoma cell growth. Hence, the present findings suggest that TANG may be a therapeutic agent for glioblastoma treatment. PMID:27261630

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

    PubMed Central

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

    2016-01-01

    Although p53-mediated cell cycle arrest, senescence and apoptosis are well accepted as major tumor suppression mechanisms, the loss of these functions does not directly lead to tumorigenesis, suggesting that the precise roles of these canonical activities of p53 need to be redefined. Here, we report that the cells derived from the mutant mice expressing p533KR, an acetylation-defective mutant that fails to induce cell-cycle arrest, senescence and apoptosis, exhibit high levels of aneuploidy upon DNA damage. Moreover, the embryonic lethality caused by the deficiency of XRCC4, a key DNA double strand break repair factor, can be fully rescued in the p533KR/3KR background. Notably, despite high levels of genomic instability, p533KR/3KRXRCC4−/− mice, unlike p53−/− XRCC4−/− mice, are not succumbed to pro-B-cell lymphomas. Nevertheless, p533KR/3KR XRCC4−/− mice display aging-like phenotypes including testicular atrophy, kyphosis, and premature death. Further analyses demonstrate that SLC7A11 is downregulated and that p53-mediated ferroptosis is significantly induced in spleens and testis of p533KR/3KRXRCC4−/− mice. These results demonstrate that the direct role of p53-mediated cell cycle arrest, senescence and apoptosis is to control genomic stability in vivo. Our study not only validates the importance of ferroptosis in p53-mediated tumor suppression in vivo but also reveals that the combination of genomic instability and activation of ferroptosis may promote aging-associated phenotypes. PMID:26943586

  4. Sonoporation induces apoptosis and cell cycle arrest in human promyelocytic leukemia cells.

    PubMed

    Zhong, Wenjing; Sit, Wai Hung; Wan, Jennifer M F; Yu, Alfred C H

    2011-12-01

    Despite being a transient biophysical phenomenon, sonoporation is known to disturb the homeostasis of living cells. This work presents new evidence on how sonoporation may lead to antiproliferation effects including cell-cycle arrest and apoptosis through disrupting various cell signaling pathways. Our findings were obtained from sonoporation experiments conducted on HL-60 human promyelocytic leukemia cells (with 1% v/v microbubbles; 1 MHz ultrasound; 0.3 or 0.5MPa peak negative pressure; 10% duty cycle; 1 kHz pulse repetition frequency; 1 min exposure period). Membrane resealing in these sonoporated cells was first verified using scanning electron microscopy. Time-lapse flow cytometry analysis of cellular deoxyribonucleic acid (DNA) contents was then performed at four post-sonoporation time points (4 h, 8 h, 12 h and 24 h). Results indicate that an increasing trend in the apoptotic cell population can be observed for at least 12 h after sonoporation, whilst viable sonoporated cells are found to temporarily accumulate in the G(2)/M (gap-2/mitosis) phase of the cell cycle. Further analysis using western blotting reveals that sonoporation-induced apoptosis involves cleavage of poly adenosine diphosphate ribose polymerase (PARP) proteins: a pro-apoptotic hallmark related to loss of DNA repair functionality. Also, mitochondrial signaling seems to have taken part in triggering this cellular event as the expression of two complementary regulators for mitochondrial release of pro-apoptotic molecules, Bcl-2 (B-cell lymphoma 2) and Bax (Bcl-2-associated X), are seen to be imbalanced in sonoporated cells. Furthermore, sonoporation is found to induce cell-cycle arrest through perturbing the expression of various cyclin and Cdk (cyclin-dependent kinase) checkpoint proteins that play an enabling role in cell-cycle progression. These bioeffects should be taken into account when using sonoporation for therapeutic purposes. PMID:22033133

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

    PubMed

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

    2014-01-01

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

  6. Human T-cell leukemia virus type 1 Tax releases cell cycle arrest induced by p16INK4a.

    PubMed Central

    Low, K G; Dorner, L F; Fernando, D B; Grossman, J; Jeang, K T; Comb, M J

    1997-01-01

    The human T-cell leukemia virus type 1 (HTLV-1) Tax oncoprotein causes cellular transformation by deregulating important cellular processes such as DNA repair, transcription, signal transduction, proliferation, and growth. Although it is clear that normal cell cycle control is deregulated during HTLV-1-induced cellular transformation, the effects of Tax on cell cycle control are not well understood. Flow cytometric analyses of human T cells indicate that cell cycle arrest in late G1, at or before the G1/S restriction point, by p16INK4a is relieved by Tax. Furthermore, Tax-dependent stimulation of 5-bromo-2'-deoxyuridine incorporation and transcriptional activation is inhibited by p16INK4a. This result suggests that p16INK4a is able to block Tax-dependent stimulation of DNA synthesis and cell cycle progression into S phase. In vitro binding assays with recombinant glutathione S-transferase fusion proteins and [35S]methionine-labeled proteins indicate that Tax binds specifically with p16INK4a but not with either p21cip1 or p27kip1. Furthermore, sequential immunoprecipitation assays with specific antisera and [35S]methionine-labeled cell lysates subsequent to coexpression with Tax and p16INK4a indicate that the two proteins form complexes in vivo. Immunocomplex kinase assays with cyclin-dependent kinase 4 antiserum indicate that Tax blocks the inhibition of cdk4 kinase activity by p16INK4a. This study identifies p16INK4a as a novel cellular target for Tax and suggests that the inactivation of p16INK4a function is a mechanism of cell cycle deregulation by Tax. PMID:9032327

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

    PubMed

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

    2011-10-15

    Anti-Candida potential of six terpenoids were evaluated in this study against various isolates of Candida albicans (n=39) and non-C. albicans (n=9) that are differentially susceptible to fluconazole. All the six terpenoids tested, showed excellent activity and were equally effective against isolates of Candida sps., tested in this study. Linalool and citral were the most effective ones, inhibiting all the isolates at ≤0.064% (v/v). Five among the six terpenoids tested were fungicidal. Time dependent kill curve assay showed that MFCs of linalool and eugenol were highly toxic to C. albicans, killing 99.9% inoculum within seven min of exposure, while that of citronellal, linalyl acetate and citral required 15min, 1h and 2h, respectively. FIC index values (Linalool - 0.140, benzyl benzoate - 0.156, eugenol - 0.265, citral - 0.281 and 0.312 for linalyl acetate and citronellal) and isobologram obtained by checker board assay showed that all the six terpenoids tested exhibit excellent synergistic activity with fluconazole against a fluconazole resistant strain of C. albicans. Terpenoids tested arrested C. albicans cells at different phases of the cell cycle i.e. linalool and LA at G1, citral and citronellal at S phase and benzyl benzoate at G2-M phase and induced apoptosis. Linalool, citral, citronellal and benzyl benzoate caused more than 50% inhibition of germ tube induction at 0.008%, while eugenol and LA required 0.032 and 0.016% (v/v) concentrations, respectively. MICs of all the terpenoids for the C. albicans growth were non toxic to HeLa cells. Terpenoids tested exhibited excellent activity against C. albicans yeast and hyphal form growth at the concentrations that are non toxic to HeLa cells. Terpenoids tested in this study may find use in antifungal chemotherapy, not only as antifungal agents but also as synergistic agents along with conventional drugs like fluconazole. PMID:21596542

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

    SciTech Connect

    Rowley, R.

    1985-09-01

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

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

    PubMed

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

    2016-06-01

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

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

    PubMed

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

    2009-04-17

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

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

    PubMed

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

    2014-01-01

    Ionizing radiation (IR) treatment induces a DNA damage response, including cell cycle arrest, DNA repair, and apoptosis in metazoan somatic cells. Because little has been reported in germline cells, we performed a temporal analysis of the DNA damage response utilizing Drosophila oogenesis as a model system. Oogenesis in the adult Drosophila female begins with the generation of 16-cell cyst by four mitotic divisions of a cystoblast derived from the germline stem cells. We found that high-dose irradiation induced S and G2 arrests in these mitotically dividing germline cells in a grp/Chk1- and mnk/Chk2-dependent manner. However, the upstream kinase mei-41, Drosophila ATR ortholog, was required for the S-phase checkpoint but not for the G2 arrest. As in somatic cells, mnk/Chk2 and dp53 were required for the major cell death observed in early oogenesis when oocyte selection and meiotic recombination occurs. Similar to the unscheduled DNA double-strand breaks (DSBs) generated from defective repair during meiotic recombination, IR-induced DSBs produced developmental defects affecting the spherical morphology of meiotic chromosomes and dorsal-ventral patterning. Moreover, various morphological abnormalities in the ovary were detected after irradiation. Most of the IR-induced defects observed in oogenesis were reversible and were restored between 24 and 96 h after irradiation. These defects in oogenesis severely reduced daily egg production and the hatch rate of the embryos of irradiated female. In summary, irradiated germline cells induced DSBs, cell cycle arrest, apoptosis, and developmental defects resulting in reduction of egg production and defective embryogenesis. PMID:24551207

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

    PubMed Central

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

    2015-01-01

    Colorectal cancer (CRC) is one of the most common malignancies worldwide with substantial mortality and morbidity. Alisertib (ALS) is a selective Aurora kinase A (AURKA) inhibitor with unclear effect and molecular interactome on CRC. This study aimed to evaluate the molecular interactome and anticancer effect of ALS and explore the underlying mechanisms in HT29 and Caco-2 cells. ALS markedly arrested cells in G2/M phase in both cell lines, accompanied by remarkable alterations in the expression level of key cell cycle regulators. ALS induced apoptosis in HT29 and Caco-2 cells through mitochondrial and death receptor pathways. ALS also induced autophagy in HT29 and Caco-2 cells, with the suppression of phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR), but activation of 5′ AMP-activated protein kinase (AMPK) signaling pathways. There was a differential modulating effect of ALS on p38 MAPK signaling pathway in both cell lines. Moreover, induction or inhibition of autophagy modulated basal and ALS-induced apoptosis in both cell lines. ALS potently suppressed epithelial to mesenchymal transition (EMT) in HT29 and Caco-2 cells. Collectively, it suggests that induction of cell cycle arrest, promotion of apoptosis and autophagy, and suppression of EMT involving mitochondrial, death receptor, PI3K/Akt/mTOR, p38 MAPK, and AMPK signaling pathways contribute to the cancer cell killing effect of ALS on CRC cells. PMID:26729093

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

    PubMed

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

    2015-01-01

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

  14. Niclosamide inhibits the proliferation of human osteosarcoma cell lines by inducing apoptosis and cell cycle arrest.

    PubMed

    Li, Zonghuan; Yu, Yifeng; Sun, Shaoxing; Qi, Baiwen; Wang, Weiyang; Yu, Aixi

    2015-04-01

    Niclosamide, used as an antihelminthic, has demonstrated some properties of anticancer effects. However, its role in osteosarcoma remains to be determined. The aim of this study was to determine the effect of niclosamide on human osteosarcoma cell lines. The human MG-63 and U2OS osteosarcoma cell lines were treated with different concentrations of niclosamide. The cell inhibitory rate was calculated by CCK-8 assay. Cell cycle was detected by flow cytometry. Cell apoptosis was determined by Hoechst 33324 staining, flow cytometry and fluorescence microscope, respectively. The expression of bcl-2, bax and pro-caspase-3 were measured by western blotting. Niclosamide exerted an inhibitory effect on the two cell lines in a time- and dose-dependent manner. Niclosamide was found to induce the arrest of S and G2/M phase in U2OS cells and G2/M in MG-63 cells. Moreover, niclosamide induced apoptosis in MG-63 and U2OS cells. The bax/bcl-2 ratio increased while the expression of pro‑caspase-3 decreased significantly in the two cell lines. The results indicated that niclosamide inhibits proliferation, and induces apoptosis and cell cycle arrest in human osteosarcoma cell lines. PMID:25634333

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

    SciTech Connect

    Byrne, Ann; McLaren, Rajashree P.; Mason, Paul; Chai, Lilly; Dufault, Michael R.; Huang, Yinyin; Liang, Beirong; Gans, Joseph D.; Zhang, Mindy; Carter, Kara; Gladysheva, Tatiana B.; Teicher, Beverly A.; Biemann, Hans-Peter N.; Booker, Michael; Goldberg, Mark A.; Klinger, Katherine W.; Lillie, James; Madden, Stephen L.; Jiang, Yide

    2010-01-15

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

  16. Bumetanide-induced NKCC1 inhibition attenuates oxygen-glucose deprivation-induced decrease in proliferative activity and cell cycle progression arrest in cultured OPCs via p-38 MAPKs.

    PubMed

    Fu, Peicai; Tang, Ronghua; Yu, Zhiyuan; Huang, Shanshan; Xie, Minjie; Luo, Xiang; Wang, Wei

    2015-07-10

    The Na-K-Cl co-transporter 1 (NKCC1; a member of the cation-chloride co-transporter family) mediates the coupled movement of Na(+) and/or K(+) with Cl(-) across the plasma membrane of cells (Haas and Forbush, 2000, Annu. Rev. Physiol., 62, 515-534; Russell, 2000, Physiol. Rev., 80, 211-276). Although it acts as an important regulator of cell volume, secretion, and modulator of cell apoptosis and proliferation (Chen et al., 2005, J. Cereb. Blood Flow Metab., 25, 54-66; Kahle et al., 2008, Nat. Clin. Pract. Neurol., 4, 490-503; Kidokoro et al., 2014, Am. J. Physiol. Ren. Physiol., 306, F1155-F1160; Wang et al., 2011, Cell. Physiol. Biochem., 28, 703-714), NKCC1׳s effects on oligodendrocyte precursor cells (OPCs) have not been characterized. The aim of this study was to investigate whether and to what extent inhibition of NKCC1 alters oxygen glucose deprivation (OGD)-induced cell cycle progression. In the present study, we demonstrated that inhibition of NKCC1 with bumetanide attenuates the decrease in OGD-induced DNA synthesis in cultured OPCs. Western blots showed that NKCC1 inhibition led to an increased expression of cyclin D1, CDK 4, and cyclin E in OGD-treated cells. Furthermore, our results showed bumetanide attenuated the decrease in OGD-induced proliferation and arrest of cell cycle progression via the P-38 MAPK signaling cascade. Thus, NKCC1 plays important roles in the proliferation of OPCs under OGD-induced stress. PMID:25881895

  17. p27Kip1 Is Required to Mediate a G1 Cell Cycle Arrest Downstream of ATM following Genotoxic Stress.

    PubMed

    Cassimere, Erica K; Mauvais, Claire; Denicourt, Catherine

    2016-01-01

    The DNA damage response (DDR) is a coordinated signaling network that ensures the maintenance of genome stability under DNA damaging stress. In response to DNA lesions, activation of the DDR leads to the establishment of cell cycle checkpoints that delay cell-cycle progression and allow repair of the defects. The tumor suppressor p27Kip1 is a cyclin-CDK inhibitor that plays an important role in regulating quiescence in a variety of tissues. Several studies have suggested that p27Kip1 also plays a role in the maintenance of genomic integrity. Here we demonstrate that p27Kip1 is essential for the establishment of a G1 checkpoint arrest after DNA damage. We also uncovered that ATM phosphorylates p27Kip1 on a previously uncharacterized residue (Ser-140), which leads to its stabilization after induction of DNA double-strand breaks. Inhibition of this stabilization by replacing endogenous p27Kip1 with a Ser-140 phospho-mutant (S140A) significantly sensitized cells to IR treatments. Our findings reveal a novel role for p27Kip1 in the DNA damage response pathway and suggest that part of its tumor suppressing functions relies in its ability to mediate a G1 arrest after the induction of DNA double strand breaks. PMID:27611996

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

    SciTech Connect

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

    2013-05-25

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

  19. Phloretin induces cell cycle arrest and apoptosis of human glioblastoma cells through the generation of reactive oxygen species.

    PubMed

    Liu, Yuanyuan; Fan, Chenghe; Pu, Lv; Wei, Cui; Jin, Haiqiang; Teng, Yuming; Zhao, Mingming; Yu, Albert Cheung Hoi; Jiang, Feng; Shu, Junlong; Li, Fan; Peng, Qing; Kong, Jian; Pan, Bing; Zheng, Lemin; Huang, Yining

    2016-06-01

    Phloretin, a flavonoid present in various plants, has been reported to exert anticarcinogenic effects. However, the mechanism of its chemo-preventive effect on human glioblastoma cells is not fully understood. This study aimed to investigate the molecular mechanism of phloretin and its associated chemo-preventive effect in human glioblastoma cells. The results indicate that phloretin inhibited cell proliferation by inducing cell cycle arrest at the G0-G1 phase and induced apoptosis of human glioblastoma cells. Phloretin-induced cell cycle arrest was associated with increased expression of p27 and decreased expression of cdk2, cdk4, cdk6, cyclinD and cyclinE. Moreover, the PI3K/AKT/mTOR signaling cascades were suppressed by phloretin in a dose-dependent manner. In addition, phloretin triggered the mitochondrial apoptosis pathway and generated reactive oxygen species (ROS). This was accompanied by the up-regulation of Bax, Bak and c-PARP and the down-regulation of Bcl-2. The antioxidant agents N-acetyl-L-cysteine and glutathione weakened the effect of phloretin on glioblastoma cells. In conclusion, these results demonstrate that phloretin exerts potent chemo-preventive activity in human glioblastoma cells through the generation of ROS. PMID:26983952

  20. Polyphenol-rich extract of Salvia chinensis exhibits anticancer activity in different cancer cell lines, and induces cell cycle arrest at the G0/G1-phase, apoptosis and loss of mitochondrial membrane potential in pancreatic cancer cells

    PubMed Central

    ZHAO, QUAN; HUO, XUE-CHEN; SUN, FU-DONG; DONG, RUI-QIAN

    2015-01-01

    Pancreatic cancer (PC) is one of the most aggressive types of human malignancy, which has an overall 5-year survival rate of <2%. PC is the fourth most common cause of cancer-associated mortality in the western world. At present, there is almost no effective treatment available for the treatment of PC. The aim of the present study was to evaluate the anticancer potential of a polyphenol enriched extract obtained from Salvia chinensis, a Chinese medicinal plant. An MTT assay was used to evaluate the cell viability of five cancer cell lines and one normal cell line. In addition, the effects of the extract on apoptotic induction, cell cycle phase distribution, DNA damage and loss of mitochondrial membrane potential (ΛΨm) were evaluated in MiapaCa-2 human PC cells. The effects of the extract on cell cycle phase distribution and ΛΨm were assessed by flow cytometry, using propidium iodide and rhodamine-123 DNA-binding fluorescent dyes, respectively. Fluorescence microscopy, using 4′,6-diamidino-2-phenylindole as a staining agent, was performed in order to detect the morphological changes of the MiapaCa-2 cancer cells and the presence of apoptotic bodies following treatment with the extract. The results of the present study demonstrated that the polyphenol-rich extract from S. chinensis induced potent cytotoxicity in the MCF-7 human breast cancer cells, A549 human lung cancer cells, HCT-116 and COLO 205 human colon cancer cells, and MiapaCa-2 human PC cells. The COLO 205 and MCF-7 cancer cell lines were the most susceptible to treatment with the extract, which exhibited increased rate of growth inhibition. Fluorescence microscopy revealed characteristic morphological features of apoptosis and detected the appearance of apoptotic bodies following treatment with the extract in the PC cells. Flow cytometric analysis demonstrated that the extract induced G0/G1 cell cycle arrest in a dose-dependent manner. In addition, treatment with the extract induced a significant and

  1. Novel mechanism of harmaline on inducing G2/M cell cycle arrest and apoptosis by up-regulating Fas/FasL in SGC-7901 cells.

    PubMed

    Wang, Yihai; Wang, Chunhua; Jiang, Chenguang; Zeng, Hong; He, Xiangjiu

    2015-01-01

    Harmaline (HAR), a natural occurrence β-carboline alkaloid, was isolated from the seeds of Peganum harmala and exhibited potent antitumor effect. In this study, the anti-gastric tumor effects of HAR were firstly investigated in vitro and in vivo. The results strongly showed that HAR could inhibit tumor cell proliferation and induce G2/M cell cycle arrest accompanied by an increase in apoptotic cell death in SGC-7901 cancer cells. HAR could up-regulate the expressions of cell cycle-related proteins of p-Cdc2, p21, p-p53, Cyclin B and down-regulate the expression of p-Cdc25C. In addition, HAR could up-regulate the expressions of Fas/FasL, activated Caspase-8 and Caspase-3. Moreover, blocking Fas/FasL signaling could markedly inhibit the apoptosis caused by HAR, suggesting that Fas/FasL mediated pathways were involved in HAR-induced apoptosis. Interestingly, HAR could also exert on antitumor activity with a dose of 15 mg/kg/day in vivo, which was also related with cell cycle arrest. These new findings provided a framework for further exploration of HAR which possess the potential antitumor activity by inducing cell cycle arrest and apoptosis. PMID:26678950

  2. Novel mechanism of harmaline on inducing G2/M cell cycle arrest and apoptosis by up-regulating Fas/FasL in SGC-7901 cells

    PubMed Central

    Wang, Yihai; Wang, Chunhua; Jiang, Chenguang; Zeng, Hong; He, Xiangjiu

    2015-01-01

    Harmaline (HAR), a natural occurrence β-carboline alkaloid, was isolated from the seeds of Peganum harmala and exhibited potent antitumor effect. In this study, the anti-gastric tumor effects of HAR were firstly investigated in vitro and in vivo. The results strongly showed that HAR could inhibit tumor cell proliferation and induce G2/M cell cycle arrest accompanied by an increase in apoptotic cell death in SGC-7901 cancer cells. HAR could up-regulate the expressions of cell cycle-related proteins of p-Cdc2, p21, p-p53, Cyclin B and down-regulate the expression of p-Cdc25C. In addition, HAR could up-regulate the expressions of Fas/FasL, activated Caspase-8 and Caspase-3. Moreover, blocking Fas/FasL signaling could markedly inhibit the apoptosis caused by HAR, suggesting that Fas/FasL mediated pathways were involved in HAR-induced apoptosis. Interestingly, HAR could also exert on antitumor activity with a dose of 15 mg/kg/day in vivo, which was also related with cell cycle arrest. These new findings provided a framework for further exploration of HAR which possess the potential antitumor activity by inducing cell cycle arrest and apoptosis. PMID:26678950

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

    NASA Astrophysics Data System (ADS)

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

    2013-05-01

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

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

    NASA Technical Reports Server (NTRS)

    Hughes-Fulford, M.

    1994-01-01

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

  5. Mitochondrial Uncoupling Protein 2 Induces Cell Cycle Arrest and Necrotic Cell Death

    PubMed Central

    Palanisamy, Arun P.; Cheng, Gang; Sutter, Alton G.; Evans, Zachary P.; Polito, Carmen C.; Jin, Lan; Liu, John; Schmidt, Michael G.

    2014-01-01

    Abstract Uncoupling protein 2 (UCP2) is a mitochondrial membrane protein that regulates energy metabolism and reactive oxygen species (ROS) production. We generated mouse carboxy- and amino-terminal green fluorescent protein (GFP)-tagged UCP2 constructs to investigate the effect of UCP2 expression on cell proliferation and viability. UCP2-transfected Hepa 1–6 cells did not show reduced cellular adenosine triphosphate (ATP) but showed increased levels of glutathione. Flow cytometry analysis indicated that transfected cells were less proliferative than nontransfected controls, with most cells blocked at the G1 phase. The effect of UCP2 on cell cycle arrest could not be reversed by providing exogenous ATP or oxidant supply, and was not affected by the chemical uncoupler carbonyl cyanide-p-trifluoromethoxyphenylhydrazone (FCCP). However, this effect of UCP2 was augmented by treatment with genistein, a tyrosine kinase inhibitor, which by itself did not affect cell proliferation on control hepatocytes. Western blotting analysis revealed decreased expression levels of CDK6 but not CDK2 and D-type cyclins. Examination of cell viability in UCP2-transfected cells with Trypan Blue and Annexin-V staining revealed that UCP2 transfection led to significantly increased cell death. However, characteristics of apoptosis were absent in UCP2-transfected Hepa 1–6 cells, including lack of oligonucleosomal fragmentation (laddering) of chromosomal DNA, release of cytochrome c from mitochondria, and cleavage of caspase-3. In conclusion, our results indicate that UCP2 induces cell cycle arrest at G1 phase and causes nonapoptotic cell death, suggesting that UCP2 may act as a powerful influence on hepatic regeneration and cell death in the steatotic liver. PMID:24320727

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

    PubMed

    He, Licheng; Lu, Na; Dai, Qinsheng; Zhao, Yue; Zhao, Li; Wang, Hu; Li, Zhiyu; You, Qidong; Guo, Qinglong

    2013-10-01

    Wogonin, a naturally occurring mono-flavonoid, has been reported to have tumor therapeutic potential and good selectivity both in vitro and in vivo. Herein, we investigated the anti-proliferation effects and associated mechanisms of wogonin in human colorectal cancer in vitro. The flow-cytometric analysis showed that wogonin induced a G1 phase cell cycle arrest in HCT116 cells in a concentration- and time-dependent manner. Meanwhile, the cell cycle-related proteins, such as cyclin A, E, D1, and CDK2, 4 were down-regulated in wogonin-induced G1 cell cycle arrest. Furthermore, we showed that the anti-proliferation and G1 arrest effect of wogonin on HCT116 cells was associated with deregulation of Wnt/β-catenin signaling pathway. Wogonin-treated cells showed decreased intracellular levels of Wnt proteins, and activated degradation complex to phosphorylated and targeted β-catenin for proteasomal degradation. Wogonin inhibited β-catenin-mediated transcription by interfering in the transcriptional activity of TCF/Lef, and repressing the kinase activity of CDK8 which has been considered as an oncogene involving in the development of colorectal cancers. Moreover, CDK8 siRNA-transfected HCT116 cells showed similar results to wogonin treated cells. Thus, our data suggested that wogonin induced anti-proliferation and G1 arrest via Wnt/β-catenin signaling pathway and it can be developed as a therapeutic agent against human colorectal cancer. PMID:23907061

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

    PubMed Central

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

    2013-01-01

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

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

    PubMed

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

    2016-01-01

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

  9. Cucurbitacin E Induces Cell Cycle G2/M Phase Arrest and Apoptosis in Triple Negative Breast Cancer

    PubMed Central

    Zhou, Zhongmei; Xia, Houjun; Qiu, Ming-Hua; Chen, Ceshi

    2014-01-01

    Triple negative breast cancer (TNBC) is a highly aggressive form of breast cancer resistant to many common treatments. In this study, we compared the effects of 12 phytochemical drugs on four cancer cell lines, and noticed that Cucurbitacin E (CuE) significantly inhibited TNBC cell growth by inducing cell cycle G2/M phase arrest and apoptosis. CuE reduced expression of Cyclin D1, Survivin, XIAP, Bcl2, and Mcl-1 in MDA-MB-468 and SW527, and within MDA-MB-468, CuE significantly increased activation of JNK and inhibited activation of AKT and ERK. Collectively, these results suggest that CuE may be a viable compound for developing novel TNBC therapeutics. PMID:25072848

  10. Perillyl alcohol and perillic acid induced cell cycle arrest and apoptosis in non small cell lung cancer cells.

    PubMed

    Yeruva, Laxmi; Pierre, Keon J; Elegbede, Abiodun; Wang, Robert C; Carper, Stephen W

    2007-11-18

    Plant products such as perillyl alcohol have been reported to possess anti-tumor activities against a number of human cancers though the mechanism of action has not yet been elucidated. The effects of perillyl alcohol (POH) and its metabolite perillic acid (PA) on the proliferation of non small cell lung cancer (NSCLC, A549, and H520) cells were investigated. Both POH and PA elicited dose-dependent cytotoxicity, induced cell cycle arrest and apoptosis with increasing expression of bax, p21 and caspase-3 activity in both the cell lines. Combination studies revealed that exposing the cells to an IC50 concentration of POH or PA sensitized the cells to cisplatin and radiation in a dose-dependent manner. These results indicate that POH and PA in combination therapy may have chemotherapeutic value against NSCLC. PMID:17888568

  11. Smad4 sensitizes colorectal cancer to 5-fluorouracil through cell cycle arrest by inhibiting the PI3K/Akt/CDC2/survivin cascade.

    PubMed

    Zhang, Binhao; Leng, Chao; Wu, Chao; Zhang, Zhanguo; Dou, Lei; Luo, Xin; Zhang, Bixiang; Chen, Xiaoping

    2016-03-01

    5-Fluorouracil (5-FU), a cell cycle-specific antimetabolite, is one of the most commonly used chemotherapeutic agents for colorectal cancer (CRC). Yet, resistance to 5-FU-based chemotherapy is still an obstacle to the treatment of this malignancy. Mutation or loss of Smad4 in CRC is pivotal for chemoresistance. However, the mechanism by which Smad4 regulates the chemosensitivity of CRC remains unclear. In the present study, we investigated the role of Smad4 in the chemosensitivity of CRC to 5-FU, and whether Smad4-regulated cell cycle arrest is involved in 5-FU chemoresistance. We used Smad4-expressing CT26 and Smad4-null SW620 cell lines as experimental models, by knockdown or transgenic overexpression. Cells or tumors were treated with 5-FU to determine chemosensitivity by cell growth, tumorigenicity assay and a mouse model. Cell cycle distribution was examined with flow cytometric analysis, and cell cycle-related proteins were examined by western blotting. Smad4 deficiency in CT26 and SW620 cells induced chemoresistance to 5-FU both in vitro and in vivo. Smad4 deficiency attenuated G1 or G2 cell cycle arrest by activating the PI3K/Akt/CDC2/survivin pathway. The PI3K inhibitor, LY294002, reversed the activation of the Akt/CDC2/survivin cascade in the Smad4-deficient cells, while it had little effect on cells with high Smad4 expression. In conclusion, we discovered a novel mechanism mediated by Smad4 to trigger 5-FU chemosensitivity through cell cycle arrest by inhibiting the PI3K/Akt/CDC2/survivin cascade. The present study also implies that LY294002 has potential therapeutic value to reverse the chemosensitivity of CRC with low Smad4 expression. PMID:26647806

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

    PubMed

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

    2007-01-01

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

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

    SciTech Connect

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

    2015-04-17

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

  14. Cell cycle arrest associated with anoxia-induced quiescence, anoxic preconditioning, and embryonic diapause in embryos of the annual killifish Austrofundulus limnaeus

    PubMed Central

    Meller, Camie L.; Meller, Robert; Simon, Roger P.; Culpepper, Kristin M.; Podrabsky, Jason E.

    2012-01-01

    Embryos of the annual killifish Austrofundulus limnaeus can enter into dormancy associated with diapause and anoxia-induced quiescence. Dormant embryos are composed primarily of cells arrested in the G1/G0 phase of the cell cycle based on flow cytometry analysis of DNA content. In fact, most cells in developing embryos contain only a diploid complement of DNA, with very few cells found in the S, G2, or M phases of the cell cycle. Diapause II embryos appear to be in a G0-like state with low levels of cyclin D1 and p53. However, the active form of pAKT is high during diapause II. Exposure to anoxia causes an increase in cyclin D1 and p53 expression in diapause II embryos, suggesting a possible re-entry into the cell cycle. Post-diapause II embryos exposed to anoxia or anoxic preconditioning have stable levels of cyclin D1 and stable or reduced levels of p53. The amount of pAKT is severely reduced in 12 dpd embryos exposed to anoxia or anoxic preconditioning. This study is the first to evaluate cell cycle control in embryos of A. limnaeus during embryonic diapause and in response to anoxia and builds a foundation for future research on the role of cell cycle arrest in supporting vertebrate dormancy. PMID:22570106

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

    PubMed Central

    2014-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2015-04-01

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

  17. Epithelial to Mesenchymal Transition induces cell cycle arrest and parenchymal damage in renal fibrosis

    PubMed Central

    Lovisa, Sara; LeBleu, Valerie S.; Tampe, Björn; Sugimoto, Hikaru; Vadnagara, Komal; Carstens, Julienne L.; Wu, Chia–Chin; Hagos, Yohannes; Burckhardt, Birgitta C.; Pentcheva–Hoang, Tsvetelina; Nischal, Hersharan; Allison, James P.; Zeisberg, Michael; Kalluri, Raghu

    2015-01-01

    Kidney fibrosis is marked by an epithelial–to–mesenchymal transition (EMT) by tubular epithelial cells (TECs). Here we find that during renal fibrosis TECs acquire a partial EMT program during which they remain associated with their basement membrane and express markers of both epithelial and mesenchymal cells. The functional consequence of EMT program during fibrotic injury is an arrest in the G2 phase of the cell cycle and lower expression of several transporters in TECs. We also found that transgenic expression of Twist or Snai1 expression is sufficient to promote prolonged TGF-β1–induced G2 arrest of TECs, limiting their potential for repair and regeneration. Also, in mouse models of experimentally-induced renal fibrosis, conditional deletion of Twist1 or Snai1 in proximal TECs resulted in inhibition of the EMT program and the maintenance of TEC integrity, while restoring proliferation, de–differentiation–associated repair and regeneration of the kidney parenchyma and attenuating interstitial fibrosis. Thus, inhibition of EMT program in TECs during chronic renal injury represents a potential anti–fibrosis therapy PMID:26236991

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

    PubMed

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

    2015-08-01

    Human cutaneous melanoma is an aggressive and chemotherapy-resistant type of cancer. AM251 is a cannabinoid type 1 (CB1) receptor antagonist/inverse agonist with off-target antitumor activity against pancreatic and colon cancer cells. The current study aimed to characterize the in-vitro antimelanoma activity of AM251. The BRAF V600E mutant melanoma cell line, A375, was used as an in-vitro model system. Characterization tools included a cell viability assay, nuclear morphology assessment, gene expression, western blot, flow cytometry with Annexin V-FITC/7-AAD double staining, cell cycle analyses, and measurements of changes in intracellular cAMP and calcium concentrations. AM251 exerted a marked cytotoxic effect against A375 human melanoma cells with potency comparable with that observed for cisplatin without significant changes in the human dermal fibroblasts viability. AM251, at a concentration that approximates the IC50, downregulated genes encoding antiapoptotic proteins (BCL2 and survivin) and increased transcription levels of proapoptotic BAX, induced alteration of Annexin V reactivity, DNA fragmentation, chromatin condensation in the cell nuclei, and G2/M phase arrest.AM251 also induced a 40% increase in the basal cAMP levels, but it did not affect intracellular calcium concentrations. The involvement of GPR55, TRPA1, and COX-2 in the AM251 mechanism of action was excluded. The combination of AM251 with celecoxib produced a synergistic antitumor activity, although the mechanism underlying this effect remains to be elucidated. This study provides the first evidence of a proapoptotic effect and G2/M cell cycle arrest of AM251 on A375 cells. This compound may be a potential prototype for the development of promising diarylpyrazole derivatives to be evaluated in human cutaneous melanoma. PMID:25974027

  19. Short-chain fatty acid-initiated cell cycle arrest and apoptosis of colonic epithelial cells is linked to mitochondrial function.

    PubMed

    Heerdt, B G; Houston, M A; Augenlicht, L H

    1997-05-01

    Butyrate, a short-chain fatty acid produced during microbial fermentation of fiber, induces growth arrest, differentiation, and apoptosis of colonic epithelial cells in vitro, and our prior work has shown that this induction is tightly linked to mitochondrial activity. Here we demonstrate that 12 h following induction, SW620 human colonic carcinoma cells accumulate simultaneously in G0-G1 and G2-M of the cell cycle. Four h later, during this G0-G1 to G2-M arrest, cells begin to undergo apoptosis. Using a series of unrelated agents that modulate mitochondrial functions, we demonstrate that mitochondrial electron transport and membrane potential are critical in initiation of this butyrate-mediated growth arrest and apoptosis. Colonic tumorigenesis is characterized by abnormalities in proliferation, apoptosis, and mitochondrial activities. Thus, butyrate may reduce risk for colon cancer by inducing a pathway that enhances mitochondrial function, ultimately resulting in initiation of growth arrest and apoptosis of colonic epithelial cells. PMID:9149903

  20. Co-treatment of THP-1 cells with naringenin and curcumin induces cell cycle arrest and apoptosis via numerous pathways.

    PubMed

    Shi, Dunyun; Xu, Yun; Du, Xin; Chen, Xuhong; Zhang, Xiaoli; Lou, Jin; Li, Ming; Zhuo, Jiacai

    2015-12-01

    Acute myeloid leukemia (AML) is a hematological malignancy with a low survival rate. Curcumin, which is a multi-targeted anticancer agent, has been shown to exert anti‑oxidant, anti‑inflammatory, anti‑mutagenic and anti‑carcinogenic activities. Naringenin is extracted from citrus fruits and exerts anti‑mutagenic and anti‑carcinogenic activities in various types of cancer cells. However, the effects of curcumin and naringenin in combination in AML cells have yet to be studied. The present study aimed to investigate the combination effects of curcumin and naringenin on the viability, cell cycle distribution and apoptosis rate of THP‑1 cells using cell viability assays, flow cytometry, and western blotting. Naringenin enhanced curcumin‑induced apoptosis and cell viability inhibition. In addition, curcumin and naringenin induced cell cycle arrest at S phase and G2/M phase. Numerous pathways, including p53, c‑Jun N‑terminal kinases (JNK), Akt and extracellular signal‑regulated kinases (ERK)1/2 pathways were markedly altered following treatment of THP‑1 cells with curcumin and naringenin. These results indicated that naringenin may enhance curcumin‑induced apoptosis through inhibiting the Akt and ERK pathways, and promoting the JNK and p53 pathways. PMID:26496980

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

    PubMed

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

    2014-12-01

    The difficulties faced in the effective treatment of ovarian cancer are multifactorial, but are mainly associated with relapse and drug resistance. Cancer stem-like cells have been reported to be an important contributor to these hindering factors. In this study, we aimed to investigate the anticancer activities of a bioactive fungal metabolite, namely terrein, against the human epithelial ovarian cancer cell line, SKOV3, primary human ovarian cancer cells and ovarian cancer stem-like cells. Terrein was separated and purified from the fermentation metabolites of the marine sponge-derived fungus, Aspergillus terreus strain PF26. Its anticancer activities against ovarian cancer cells were investigated by cell proliferation assay, cell migration assay, cell apoptosis and cell cycle assays. The ovarian cancer stem-like cells were enriched and cultured in a serum-free in vitro suspension system. Terrein inhibited the proliferation of the ovarian cancer cells by inducing G2/M phase cell cycle arrest. The underlying mechanisms involved the suppression of the expression of LIN28, an important marker gene of stemness in ovarian cancer stem cells. Of note, our study also demonstrated the ability of terrein to inhibit the proliferation of ovarian cancer stem-like cells, in which the expression of LIN28 was also downregulated. Our findings reveal that terrein (produced by fermention) may prove to be a promising drug candidate for the treatment of ovarian cancer by inhibiting the proliferation of cancer stem-like cells. PMID:25318762

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

    PubMed

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

    2016-04-01

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

  3. CFS-1686 Causes Cell Cycle Arrest at Intra-S Phase by Interference of Interaction of Topoisomerase 1 with DNA

    PubMed Central

    Ho, Cheng-Jung; Huang, Shih-Bo; Yang, Min-Chi; Chang, Hsin-Wen; Lin, Chun-Mao; Hwang, Jaulang; Chen, Yeh-Long; Tzeng, Cherg-Chyi; Wang, Chihuei

    2014-01-01

    CFS-1686 (chemical name (E)-N-(2-(diethylamino)ethyl)-4-(2-(2-(5-nitrofuran-2-yl)vinyl)quinolin-4-ylamino)benzamide) 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. PMID:25460368

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

    PubMed

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

    2015-12-01

    Gypensapogenin H (GH) is a novel dammarane-type triterpenes obtained from hydrolyzate of total saponins from Gynostemma pentaphyllum and its anti-tumor activity has been studied in previous work. In this study, we report the effects of this compound on human prostate cancer cells (DU145 and 22RV-1). It significantly inhibited proliferation, decreased survival, led to G1 cell cycle arrest and induced apoptosis in both cell lines, while having lesser effect on the growth of normal human gastric mucosa cells (GES-1), embryonic kidney cells (HEK293) and lung fibroblast cells (MRC5). Consistent with these phenotypes, we observed decreased expression of the cell cycle-related proteins cyclinD1, and CDK4, and increased expression of p21 in GH-treated cells. Besides, the anti-apoptotic Bcl-2 protein decreased in a dose-dependent manner, while Bax, cleaved caspase-3 and -9 increased upon GH treatment. Taken together, these results indicated GH exerted promising anticancer activity, and may represent a potential agent for the treatment of prostate cancer. PMID:26514740

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

    SciTech Connect

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

    2012-07-01

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

  6. A C21-Steroidal Glycoside Isolated from the Roots of Cynanchum auriculatum Induces Cell Cycle Arrest and Apoptosis in Human Gastric Cancer SGC-7901 Cells

    PubMed Central

    Wang, Yi-Qi; Zhang, Shui-Juan; Lu, Hong; Yang, Bo; Ye, Liang-Fei; Zhang, Ru-Song

    2013-01-01

    Caudatin 3-O-β-D-cymaropyranosyl-(1 → 4)-β-D-oleandropyranosyl-(1 → 4)-β-D-cymaropyranosyl-(1 → 4)-β-D-cymaropyranoside (CGII) is one of the C21-steroidal glycosides isolated from the roots of Cynanchum auriculatum ROYLE ex WIGHT. This study aimed to determine the cell growth, cell proliferation, and apoptotic cell death of human gastric cancer cells after CGII treatment. MTT assay was used to determine cell growth; fluorescence-activated cell sorting analysis was used to evaluate cell cycle distribution and apoptotic cell death. Immunoblotting was applied for measuring the expression of proteins involved in the cell cycle progression. The activities of caspase-3, -8, and -9 were detected by colorimetric caspase activity assays. CGII inhibited cell growth of human gastric cancer SGC-7901 cells in a concentration- and time-dependent manner. Treatment of SGC-7901 cells with CGII resulted in G1 phase cell cycle arrest, accompanied with decreased expression of cyclin D1 and cyclin-dependent kinases 4 and 6. CGII induced cell apoptosis and activated caspase-3, caspase-8, and caspase-9. In contrast, pan-caspase inhibitor z-VAD-fmk partially abolished the CGII-induced growth inhibition of SGC-7901 cells. In conclusion, CGII inhibits cell growth of human gastric cancer cells by inducing G1 phase cell cycle arrest and caspase-dependent apoptosis cascades. PMID:24454488

  7. Novel dichlorophenyl urea compounds inhibit proliferation of human leukemia HL-60 cells by inducing cell cycle arrest, differentiation and apoptosis.

    PubMed

    Figarola, James L; Weng, Yehua; Lincoln, Christopher; Horne, David; Rahbar, Samuel

    2012-08-01

    Two novel dichlorophenyl urea compounds, SR4 and SR9, were synthesized in our laboratory and evaluated for anti-cancer activities. Specifically, we investigated the antiproliferative properties of these new compounds on promyelocytic HL-60 leukemia cells by analyzing their effects on cell differentiation, cell cycle progression and apoptosis. SR4 and SR9 were both cytotoxic to HL-60 cells in a dose-and time-dependent manner, with IC(50) of 1.2 μM and 2.2 μM, respectively, after 72 h treatment. Both compounds strongly suppressed growth of HL-60 cells by promoting cell cycle arrest at the G0/G1 transition, with concomitant decrease in protein levels of cyclins D1 and E2 and cyclin-dependent kinases (CDK 2 and CDK 4), and increased protein expression of CDK inhibitors p21(WAF1/Cip1) and p27(Kip1). In addition, either compounds induce cell differentiation as detected by increased NBT staining and expression of CD11b and CD14. Treatment with SR compounds also promoted mitochondrial-dependent apoptosis as confirmed by Annexin V-FITC double staining, DNA fragmentation, increased expression of caspase 3, 7 and 9, cytochrome c release, PARP degradation, and collapse in mitochondrial membrane potential (ΔΨ(MT)). Collectively, these results provide evidence that SR4 and SR9 have the potential for the treatment of human leukemia and merit further investigation as therapeutic agents against other types of cancer. PMID:21728022

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

    SciTech Connect

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

    2011-07-29

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

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

    PubMed

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

    2009-06-01

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

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

    PubMed

    Tseng, Shuei-Kuen; Chang, Mei-Chi; Su, Cheng-Yao; Chi, Lin-Yang; Chang, Jenny Zwei-Ching; Tseng, Wan-Yu; Yeung, Sin-Yuet; Hsu, Ming-Lun; Jeng, Jiiang-Huei

    2012-08-01

    Betel quid (BQ) chewing is a common oral habit in South Asia and Taiwan. BQ consumption may increase the risk of oral squamous cell carcinoma (OSCC), oral submucous fibrosis (OSF), and periodontitis as well as systemic diseases (atherosclerosis, hypertension, etc.). However, little is known about the toxic effect of BQ components on endothelial cells that play important roles for angiogenesis, carcinogenesis, tissue fibrosis, and cardiovascular diseases. EAhy 926 (EAHY) endothelial cells were exposed to arecoline, a major BQ alkaloid, for various time periods. Cytotoxicity was estimated by 3-(4, 5- dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide assay. The cell cycle distribution of EAHY cells residing in sub-G0/G1, G0/G1, S-, and G2/M phases was analyzed by propidium iodide staining of cellular DNA content and flow cytometry. Some EAHY cells retracted, became round-shaped in appearance, and even detached from the culture plate after exposure to higher concentrations of arecoline (> 0.4 mM). At concentrations of 0.4 and 0.8 mM, arecoline induced significant cytotoxicity to EAHY cells. At similar concentrations, arecoline induced G2/M cell cycle arrest and increased sub-G0/G1 population, a hallmark of apoptosis. Interestingly, prolonged exposure to arecoline (0.1 mM) for 12 and 21 days significantly suppressed the proliferation of EAHY cells, whereas EAHY cells showed adaptation and survived when exposed to 0.05 mM arecoline. These results suggest that BQ components may contribute to the pathogenesis of OSF and BQ chewing-related cardiovascular diseases via toxicity to oral or systemic endothelial cells, leading to impairment of vascular function. During BQ chewing, endothelial damage may be induced by areca nut components and associate with the pathogenesis of OSF, periodontitis, and cardiovascular diseases. PMID:21847594

  11. Inhibition of the proteasome induces cell cycle arrest and apoptosis in mantle cell lymphoma cells.

    PubMed

    Bogner, Christian; Ringshausen, Ingo; Schneller, Folker; Fend, Falko; Quintanilla-Martinez, Leticia; Häcker, Georg; Goetze, Katharina; Oostendorp, Robert; Peschel, Christian; Decker, Thomas

    2003-07-01

    Mantle cell lymphoma (MCL) is a distinctive non-Hodgkin's lymphoma subtype, characterized by overexpression of cyclin D1 as a consequence of the chromosomal translocation t(11;14)(q13;q32). MCL remains an incurable disease, combining the unfavourable clinical features of aggressive and indolent lymphomas. The blastic variant of MCL, which is often associated with additional cytogenetic alterations, has an even worse prognosis and new treatment options are clearly needed. The present study investigated the effect of a specific proteasome inhibitor, lactacystin, on cell cycle progression and apoptosis in two lymphoma cell lines harbouring the t(11;14)(q13;q32) and additional cytogenetic alterations, including p53 mutation (NCEB) and p16 deletion (Granta 519). Granta cells were more susceptible to inhibition of the proteasome with respect to inhibition of proliferation and apoptosis induction. No changes were observed in the expression levels of the G1 regulatory molecules cyclin D1 and cdk4, but cell cycle arrest and apoptosis induction was accompanied by accumulation of the cdk inhibitor p21 in both cell lines. Increased p53 expression was only observed in Granta cells with wild-type p53. Cleavage of procaspase-3 and -9 was observed but cleavage of procaspase-8 was not involved in apoptosis induction. The proapoptotic effect of lactacystin was reversed by pretreatment with the pancaspase inhibitor zVAD.fmk. Lactacystin was also effective in inducing apoptosis in lymphoma cells from MCL patients. We conclude that inhibition of the proteasome might be a promising therapeutic approach for this incurable disease. PMID:12846895

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

    SciTech Connect

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

    2012-01-15

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

  13. p21 binding to PCNA causes G1 and G2 cell cycle arrest in p53-deficient cells.

    PubMed

    Cayrol, C; Knibiehler, M; Ducommun, B

    1998-01-22

    A unique feature of p21 that distinguishes it from the other cyclin-dependent kinase (CDK) inhibitors is its ability to associate with the proliferating cell nuclear antigen (PCNA), an auxiliary factor for DNA polymerases delta and epsilon. While it is now well established that inhibition of cyclin/CDK complexes by p21 can result in G1 cell cycle arrest, the consequences of p21/PCNA interaction on cell cycle progression have not yet been determined. Here, we show, using a tetracycline-regulated system, that expression of wild-type p21 in p53-deficient DLD1 human colon cancer cells inhibits DNA synthesis and causes G1 and G2 cell cycle arrest. Similar effects are observed in cells expressing p21CDK-, a mutant impaired in the interaction with CDKs, but not in cells expressing p21PCNA-, a mutant deficient for the interaction with PCNA. Analysis of cells treated with a p21-derived PCNA-binding peptide provides additional evidence that the growth inhibitory effects of p21 and p21CDK result from their ability to bind to PCNA. Our results suggest that p21 might inhibit cell cycle progression by two independent mechanisms, inhibition of cyclin/CDK complexes, and inhibition of PCNA function resulting in both G1 and G2 arrest. PMID:9467956

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

    PubMed Central

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

    2013-01-01

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

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

    PubMed Central

    Lee, Hyun Sook; Kim, Eun Ji

    2015-01-01

    BACKGROUND/OBJECTIVES Inonotus obliquus (I. obliquus, Chaga mushroom) has long been used as a folk medicine to treat cancer. In the present study, we examined whether or not ethanol extract of I. obliquus (EEIO) inhibits cell cycle progression in HT-29 human colon cancer cells, in addition to its mechanism of action. MATERIALS/METHODS To examine the effects of Inonotus obliquus on the cell cycle progression and the molecular mechanism in colon cancer cells, HT-29 human colon cancer cells were cultured in the presence of 2.5 - 10 µg/mL of EEIO, and analyzed the cell cycle arrest by flow cytometry and the cell cycle controlling protein expression by Western blotting. RESULTS Treatment cells with 2.5 - 10 µg/mL of EEIO reduced viable HT-29 cell numbers and DNA synthesis, increased the percentage of cells in G1 phase, decreased protein expression of CDK2, CDK4, and cyclin D1, increased expression of p21, p27, and p53, and inhibited phosphorylation of Rb and E2F1 expression. Among I. obliquus fractions, fraction 2 (fractionated by dichloromethane from EEIO) showed the same effect as EEIO treatment on cell proliferation and cell cycle-related protein levels. CONCLUSIONS These results demonstrate that fraction 2 is the major fraction that induces G1 arrest and inhibits cell proliferation, suggesting I. obliquus could be used as a natural anti-cancer ingredient in the food and/or pharmaceutical industry. PMID:25861415

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

    PubMed

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

    2016-01-01

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

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

    PubMed Central

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

    2016-01-01

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

  18. Knocking down nucleolin expression in gliomas inhibits tumor growth and induces cell cycle arrest.

    PubMed

    Xu, Zhiqiang; Joshi, Neel; Agarwal, Ashima; Dahiya, Sonika; Bittner, Patrice; Smith, Erin; Taylor, Sara; Piwnica-Worms, David; Weber, Jason; Leonard, Jeffrey R

    2012-05-01

    Nucleolin is a multifunctional protein whose expression often correlates with increased cellular proliferation. While the expression of nucleolin is often elevated in numerous cancers, its expression in normal human brain and in astrocytomas has not been previously reported. Using paraffin-embedded sections from normal adult autopsy specimens and glioma resection specimens, we demonstrate that nucleolin expression is limited in the normal human brain specifically to mature neurons, ependymal cells, and granular cells of the dentate gyrus. While astrocytes in the normal human brain do not express nucleolin at significant levels, glioblastoma cell lines and primary human astrocytoma cells exhibit considerable nucleolin expression. Reduction of nucleolin expression through siRNA-mediated knockdown in the U87MG glioblastoma cell line caused a dramatic decrease in cell proliferation and induced cell cycle arrest in vitro. Moreover, conditional siRNA knockdown of nucleolin expression in U87MG intracranial xenografts in nude mice caused dramatic reduction in tumor size. Taken together, these results implicate nucleolin in the regulation of human astrocytoma proliferation in vitro and tumorigenicity in vivo and suggest that nucleolin may represent a potential novel therapeutic target for astrocytomas. PMID:22382782

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

    NASA Astrophysics Data System (ADS)

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

    2013-05-01

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

  20. Septins Regulate Actin Organization and Cell Cycle Arrest Through SOCS7-Mediated Nuclear Accumulation of NCK

    PubMed Central

    Kremer, Brandon E.; Adang, Laura A.; Macara, Ian G.

    2007-01-01

    SUMMARY Mammalian septins are GTP-binding proteins the functions of which are not well understood. Knockdown of Sept2, 6, and 7 causes stress fibers to disintegrate and the cells to lose polarity. We now show that this phenotype is induced by nuclear accumulation of the adapter protein NCK, as the effects can be reversed or induced by cytoplasmic or nuclear NCK, respectively. NCK is carried into the nucleus by SOCS7 (Suppressor Of Cytokine Signaling-7), which contains nuclear import/export signals. SOCS7 interacts through distinct domains with septins and NCK. DNA damage induces actin and septin rearrangement and rapid nuclear accumulation of NCK and SOCS7. Moreover, NCK expression is essential for cell-cycle arrest. The septin-SOCS7-NCK axis intersects with the canonical DNA damage cascade downstream of ATM/ATR and is essential for p53 Ser15 phosphorylation. These data illuminate an unanticipated connection between septins, SOCS7, NCK signaling, and the DNA damage response. PMID:17803907

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

    PubMed Central

    Ugrinova, Iva; Monier, Karine; Ivaldi, Corinne; Thiry, Marc; Storck, Sébastien; Mongelard, Fabien; Bouvet, Philippe

    2007-01-01

    Background Nucleolin is a major component of the nucleolus, but is also found in other cell compartments. This protein is involved in various aspects of ribosome biogenesis from transcription regulation to the assembly of pre-ribosomal particles; however, many reports suggest that it could also play an important role in non nucleolar functions. To explore nucleolin function in cell proliferation and cell cycle regulation we used siRNA to down regulate the expression of nucleolin. Results We found that, in addition to the expected effects on pre-ribosomal RNA accumulation and nucleolar structure, the absence of nucleolin results in a cell growth arrest, accumulation in G2, and an increase of apoptosis. Numerous nuclear alterations, including the presence of micronuclei, multiple nuclei or large nuclei are also observed. In addition, a large number of mitotic cells showed a defect in the control of centrosome duplication, as indicated by the presence of more than 2 centrosomes per cell associated with a multipolar spindle structure in the absence of nucleolin. This phenotype is very similar to that obtained with the inactivation of another nucleolar protein, B23. Conclusion Our findings uncovered a new role for nucleolin in cell division, and highlight the importance of nucleolar proteins for centrosome duplication. PMID:17692122

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

    NASA Technical Reports Server (NTRS)

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

    1994-01-01

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

  3. RAD9-dependent G1 arrest defines a second checkpoint for damaged DNA in the cell cycle of Saccharomyces cerevisiae.

    PubMed Central

    Siede, W; Friedberg, A S; Friedberg, E C

    1993-01-01

    Exposure of the yeast Saccharomyces cerevisiae to ultraviolet (UV) light, the UV-mimetic chemical 4-nitroquinoline-1-oxide (4NQO), or gamma radiation after release from G1 arrest induced by alpha factor results in delayed resumption of the cell cycle. As is the case with G2 arrest following ionizing radiation damage [Weinert, T. A. & Hartwell, L. H. (1988) Science 241, 317-322], the normal execution of DNA damage-induced G1 arrest depends on a functional yeast RAD9 gene. We suggest that the RAD9 gene product may interact with cellular components common to the G1/S and G2/M transition points in the cell cycle of this yeast. These observations define a checkpoint in the eukaryotic cell cycle that may facilitate the repair of lesions that are otherwise processed to lethal and/or mutagenic damage during DNA replication. This checkpoint apparently operates after the mating pheromone-induced G1 arrest point but prior to replicative DNA synthesis, S phase-associated maximal induction of histone H2A mRNA, and bud emergence. Images Fig. 4 PMID:8367452

  4. Anti-Colon Cancer Effects of 6-Shogaol Through G2/M Cell Cycle Arrest by p53/p21-cdc2/cdc25A Crosstalk.

    PubMed

    Qi, Lian-Wen; Zhang, Zhiyu; Zhang, Chun-Feng; Anderson, Samantha; Liu, Qun; Yuan, Chun-Su; Wang, Chong-Zhi

    2015-01-01

    Chemopreventive agents can be identified from botanicals. Recently, there has been strong support for the potential of 6-shogaol, a natural compound from dietary ginger (Zingiber officinale), in cancer chemoprevention. However, whether 6-shogaol inhibits the growth of colorectal tumors in vivo remains unknown, and the underlying anticancer mechanisms have not been well characterized. In this work, we observed that 6-shogaol (15 mg/kg) significantly inhibited colorectal tumor growth in a xenograft mouse model. We show that 6-shogaol inhibited HCT-116 and SW-480 cell proliferation with IC50 of 7.5 and 10 μM, respectively. Growth of HCT-116 cells was arrested at the G2/M phase of the cell cycle, primarily mediated by the up-regulation of p53, the CDK inhibitor p21(waf1/cip1) and GADD45α, and by the down-regulation of cdc2 and cdc25A. Using p53(-/-) and p53(+/+) HCT-116 cells, we confirmed that p53/p21 was the main pathway that contributed to the G2/M cell cycle arrest by 6-shogaol. 6-Shogaol induced apoptosis, mainly through the mitochondrial pathway, and the bcl-2 family might act as a key regulator. Our results demonstrated that 6-shogaol induces cancer cell death by inducing G2/M cell cycle arrest and apoptosis. 6-Shogaol could be an active natural product in colon cancer chemoprevention. PMID:26119958

  5. Pre–B cell receptor–mediated cell cycle arrest in Philadelphia chromosome–positive acute lymphoblastic leukemia requires IKAROS function

    PubMed Central

    Trageser, Daniel; Iacobucci, Ilaria; Nahar, Rahul; Duy, Cihangir; von Levetzow, Gregor; Klemm, Lars; Park, Eugene; Schuh, Wolfgang; Gruber, Tanja; Herzog, Sebastian; Kim, Yong-mi; Hofmann, Wolf-Karsten; Li, Aihong; Storlazzi, Clelia Tiziana; Jäck, Hans-Martin; Groffen, John; Martinelli, Giovanni; Heisterkamp, Nora; Jumaa, Hassan

    2009-01-01

    B cell lineage acute lymphoblastic leukemia (ALL) arises in virtually all cases from B cell precursors that are arrested at pre–B cell receptor–dependent stages. The Philadelphia chromosome–positive (Ph+) subtype of ALL accounts for 25–30% of cases of adult ALL, has the most unfavorable clinical outcome among all ALL subtypes and is defined by the oncogenic BCR-ABL1 kinase and deletions of the IKAROS gene in >80% of cases. Here, we demonstrate that the pre–B cell receptor functions as a tumor suppressor upstream of IKAROS through induction of cell cycle arrest in Ph+ ALL cells. Pre–B cell receptor–mediated cell cycle arrest in Ph+ ALL cells critically depends on IKAROS function, and is reversed by coexpression of the dominant-negative IKAROS splice variant IK6. IKAROS also promotes tumor suppression through cooperation with downstream molecules of the pre–B cell receptor signaling pathway, even if expression of the pre–B cell receptor itself is compromised. In this case, IKAROS redirects oncogenic BCR-ABL1 tyrosine kinase signaling from SRC kinase-activation to SLP65, which functions as a critical tumor suppressor downstream of the pre–B cell receptor. These findings provide a rationale for the surprisingly high frequency of IKAROS deletions in Ph+ ALL and identify IKAROS-mediated cell cycle exit as the endpoint of an emerging pathway of pre–B cell receptor–mediated tumor suppression. PMID:19620627

  6. Cyclin G2 is a centrosome-associated nucleocytoplasmic shuttling protein that influences microtubule stability and induces a p53-dependent cell cycle arrest

    SciTech Connect

    Arachchige Don, Aruni S.; Dallapiazza, Robert F.; Bennin, David A.; Brake, Tiffany; Cowan, Colleen E.; Horne, Mary C. . E-mail: mary-horne@uiowa.edu

    2006-12-10

    Cyclin G2 is an atypical cyclin that associates with active protein phosphatase 2A. Cyclin G2 gene expression correlates with cell cycle inhibition; it is significantly upregulated in response to DNA damage and diverse growth inhibitory stimuli, but repressed by mitogenic signals. Ectopic expression of cyclin G2 promotes cell cycle arrest, cyclin dependent kinase 2 inhibition and the formation of aberrant nuclei [Bennin, D. A., Don, A. S., Brake, T., McKenzie, J. L., Rosenbaum, H., Ortiz, L., DePaoli-Roach, A. A., and Horne, M. C. (2002). Cyclin G2 associates with protein phosphatase 2A catalytic and regulatory B' subunits in active complexes and induces nuclear aberrations and a G{sub 1}/S-phase cell cycle arrest. J Biol Chem 277, 27449-67]. Here we report that endogenous cyclin G2 copurifies with centrosomes and microtubules (MT) and that ectopic G2 expression alters microtubule stability. We find exogenous and endogenous cyclin G2 present at microtubule organizing centers (MTOCs) where it colocalizes with centrosomal markers in a variety of cell lines. We previously reported that cyclin G2 forms complexes with active protein phosphatase 2A (PP2A) and colocalizes with PP2A in a detergent-resistant compartment. We now show that cyclin G2 and PP2A colocalize at MTOCs in transfected cells and that the endogenous proteins copurify with isolated centrosomes. Displacement of the endogenous centrosomal scaffolding protein AKAP450 that anchors PP2A at the centrosome resulted in the depletion of centrosomal cyclin G2. We find that ectopic expression of cyclin G2 induces microtubule bundling and resistance to depolymerization, inhibition of polymer regrowth from MTOCs and a p53-dependent cell cycle arrest. Furthermore, we determined that a 100 amino acid carboxy-terminal region of cyclin G2 is sufficient to both direct GFP localization to centrosomes and induce cell cycle inhibition. Colocalization of endogenous cyclin G2 with only one of two GFP-centrin-tagged centrioles

  7. Hydrogen peroxide inhibits transforming growth factor-β1-induced cell cycle arrest by promoting Smad3 linker phosphorylation through activation of Akt-ERK1/2-linked signaling pathway.

    PubMed

    Choi, Jiyeon; Park, Seong Ji; Jo, Eun Ji; Lee, Hui-Young; Hong, Suntaek; Kim, Seong-Jin; Kim, Byung-Chul

    2013-06-14

    Hydrogen peroxide (H2O2) functions as a second messenger in growth factor receptor-mediated intracellular signaling cascade and is tumorigenic by virtue of its ability to promote cell proliferation; however, the mechanisms underlying the growth stimulatory action of H2O2 are less understood. Here we report an important mechanism for antagonistic effects of H2O2 on growth inhibitory response to transforming growth factor-β1 (TGF-β1). In Mv1Lu and HepG2 cells, pretreatment of H2O2 (0.05-0.2 mM) completely blocked TGF-β1-mediated induction of p15(INK4B) expression and increase of its promoter activity. Interestingly, H2O2 selectively suppressed the transcriptional activation potential of Smad3, not Smad2, in the absence of effects on TGF-β1-induced phosphorylation of the COOH-tail SSXS motif of Smad3 and its nuclear translocation. Mechanism studies showed that H2O2 increases the phosphorylation of Smad3 at the middle linker region in a concentration- and time-dependent manner and this effect is mediated by activation of extracellular signal-activated kinase 1/2 through Akt. Furthermore, expression of a mutant Smad3 in which linker phosphorylation sites were ablated significantly abrogated the inhibitory effects of H2O2 on TGF-β1-induced increase of p15(INK4B)-Luc reporter activity and blockade of cell cycle progression from G1 to S phase. These findings for the first time define H2O2 as a signaling molecule that modulate Smad3 linker phosphorylation and its transcriptional activity, thus providing a potential mechanism whereby H2O2 antagonizes the cytostatic function of TGF-β1. PMID:23685151

  8. The Inhibition of Polo Kinase by Matrimony Maintains G2 Arrest in the Meiotic Cell Cycle

    PubMed Central

    Xiang, Youbin; Takeo, Satomi; Florens, Laurence; Hughes, Stacie E; Huo, Li-Jun; Gilliland, William D; Swanson, Selene K; Teeter, Kathy; Schwartz, Joel W; Washburn, Michael P; Jaspersen, Sue L; Hawley, R. Scott

    2007-01-01

    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. PMID:18052611

  9. Cucurbitacin B induced ATM-mediated DNA damage causes G2/M cell cycle arrest in a ROS-dependent manner.

    PubMed

    Guo, Jiajie; Wu, Guosheng; Bao, Jiaolin; Hao, Wenhui; Lu, Jinjian; Chen, Xiuping

    2014-01-01

    Cucurbitacins are a class of triterpenoids widely distributed in plant kingdom with potent anti-cancer activities both in vitro and in vivo by inducing cycle arrest, autophagy, and apoptosis. Cucurbitacin B (Cuc B), could induce S or G2/M cell cycle arrest in cancer cells while the detailed mechanisms remain to be clear. This study was designed to precisely dissect the signaling pathway(s) responsible for Cuc B induced cell cycle arrest in human lung adenocarcinoma epithelial A549 cells. We demonstrated that low concentrations of Cuc B dramatically induced G2/M phase arrest in A549 cells. Cuc B treatment caused DNA double-strand breaks (DSBs) without affecting the signal transducer and activator of transcription 3 (STAT3), the potential molecular target for Cuc B. Cuc B triggers ATM-activated Chk1-Cdc25C-Cdk1, which could be reversed by both ATM siRNA and Chk1 siRNA. Cuc B also triggers ATM-activated p53-14-3-3-σ pathways, which could be reversed by ATM siRNA. Cuc B treatment also led to increased intracellular reactive oxygen species (ROS) formation, which was inhibited by N-acetyl-l-cysteine (NAC) pretreatment. Furthermore, NAC pretreatment inhibited Cuc B induced DNA damage and G2/M phase arrest. Taken together, these results suggested that Cuc B induces DNA damage in A549 cells mediated by increasing intracellular ROS formation, which lead to G2/M cell phase arrest through ATM-activated Chk1-Cdc25C-Cdk1 and p53-14-3-3-σ parallel branches. These observations provide novel mechanisms and potential targets for better understanding of the anti-cancer mechanisms of cucurbitacins. PMID:24505404

  10. Cucurbitacin B Induced ATM-Mediated DNA Damage Causes G2/M Cell Cycle Arrest in a ROS-Dependent Manner

    PubMed Central

    Guo, Jiajie; Wu, Guosheng; Bao, Jiaolin; Hao, Wenhui; Lu, Jinjian; Chen, Xiuping

    2014-01-01

    Cucurbitacins are a class of triterpenoids widely distributed in plant kingdom with potent anti-cancer activities both in vitro and in vivo by inducing cycle arrest, autophagy, and apoptosis. Cucurbitacin B (Cuc B), could induce S or G2/M cell cycle arrest in cancer cells while the detailed mechanisms remain to be clear. This study was designed to precisely dissect the signaling pathway(s) responsible for Cuc B induced cell cycle arrest in human lung adenocarcinoma epithelial A549 cells. We demonstrated that low concentrations of Cuc B dramatically induced G2/M phase arrest in A549 cells. Cuc B treatment caused DNA double-strand breaks (DSBs) without affecting the signal transducer and activator of transcription 3 (STAT3), the potential molecular target for Cuc B. Cuc B triggers ATM-activated Chk1-Cdc25C-Cdk1, which could be reversed by both ATM siRNA and Chk1 siRNA. Cuc B also triggers ATM-activated p53-14-3-3-σ pathways, which could be reversed by ATM siRNA. Cuc B treatment also led to increased intracellular reactive oxygen species (ROS) formation, which was inhibited by N-acetyl-l-cysteine (NAC) pretreatment. Furthermore, NAC pretreatment inhibited Cuc B induced DNA damage and G2/M phase arrest. Taken together, these results suggested that Cuc B induces DNA damage in A549 cells mediated by increasing intracellular ROS formation, which lead to G2/M cell phase arrest through ATM-activated Chk1-Cdc25C-Cdk1 and p53-14-3-3-σ parallel branches. These observations provide novel mechanisms and potential targets for better understanding of the anti-cancer mechanisms of cucurbitacins. PMID:24505404

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

    PubMed

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

    2016-02-01

    Nobiletin, a bioactive polymethoxylated flavone (5,6,7,8,3(') ,4(') -hexamethoxyflavone), is abundant in citrus fruit peel. Although nobiletin exhibits antitumor activity against various cancer cells, the effect of nobiletin on glioma cells remains unclear. The aim of this study was to determine the effects of nobiletin on the human U87 and Hs683 glioma cell lines. Treating glioma cells with nobiletin (20-100 µm) reduced cell viability and arrested the cell cycle in the G0/G1 phase, as detected using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and propidium iodide (PI) staining, respectively; however, nobiletin did not induce cell apoptosis according to PI-annexin V double staining. Data from western blotting showed that nobiletin significantly attenuated the expression of cyclin D1, cyclin-dependent kinase 2, cyclin-dependent kinase 4, and E2 promoter-binding factor 1 (E2F1) and the phosphorylation of Akt/protein kinase B and mitogen-activated protein kinases, including p38, extracellular signal-regulated kinase, and c-Jun N-terminal kinase. Our data also showed that nobiletin inhibited glioma cell migration, as detected by both functional wound healing and transwell migration assays. Altogether, the present results suggest that nobiletin inhibits mitogen-activated protein kinase and Akt/protein kinase B pathways and downregulates positive regulators of the cell cycle, leading to subsequent suppression of glioma cell proliferation and migration. Our findings evidence that nobiletin may have potential for treating glioblastoma multiforme. PMID:26560814

  12. Oxidative stress, cell cycle arrest and differentiation contribute toward the antiproliferative action of BSO and calcitriol on Caco-2 cells.

    PubMed

    Liaudat, Ana C; Bohl, Luciana P; Tolosa de Talamoni, Nori G; Maletto, Belkys; Pistoresi-Palencia, María C; Picotto, Gabriela

    2014-08-01

    The prognosis and incidence of colon cancer are linked to vitamin D3 serum levels. To evaluate the effects of D,L-buthionine-S,R-sulfoximine (BSO), 1,25(OH)2D3 and their combination on intestinal Caco-2 cell growth, to elucidate the possible cellular mechanisms involved in their antiproliferative action, and to determine whether BSO acts as a sensitizer to 1,25(OH)2D3 treatment, enabling minimization of the toxic effects caused by high doses of the steroid. Human colon cancer Caco-2 cells were treated with 1,25(OH)2D3, BSO, both, or vehicle. Cell proliferation was evaluated by crystal violet staining. Cell cycle and mitochondrial membrane potential were measured by flow cytometry. Total glutathione, catalase, superoxide dismutase, superoxide anion levels, and alkaline phosphatase activities were analyzed by spectrophotometry. DNA fragmentation was evaluated using the terminal dUTP nick end labeling assay. BSO and 1,25(OH)2D3 inhibited Caco-2 cell growth, an effect that was higher with the combined treatment. The antiproliferative effect produced by the combination could be protected by ascorbic acid. BSO plus 1,25(OH)2D3 induced cell cycle arrest and suppressed cell division. Total glutathione decreased and superoxide anion increased with BSO and BSO plus 1,25(OH)2D3. Catalase activity increased with the combined treatment. Mitochondrial membrane potential and alkaline phosphatase activity were altered by 1,25(OH)2D3 alone or plus BSO. The percentage of terminal dUTP nick end labeling-positive cells was increased. BSO increases the antiproliferative effect of 1,25(OH)2D3 on Caco-2 cells through induction of oxidative stress, which occurs simultaneously with DNA breakage. The antioxidant system can partially compensate the damage induced by BSO plus 1,25(OH)2D3. Cell differentiation induction is also involved in the response to the combined treatment. PMID:24681551

  13. S-benzyl-cysteine-mediated cell cycle arrest and apoptosis involving activation of mitochondrial-dependent caspase cascade through the p53 pathway in human gastric cancer SGC-7901 cells.

    PubMed

    Sun, Hua-Jun; Meng, Lin-Yi; Shen, Yang; Zhu, Yi-Zhun; Liu, Hong-Rui

    2013-01-01

    S-benzyl-cysteine (SBC) is a structural analog of S-allylcysteine (SAC), which is one of the major water- soluble compounds in aged garlic extract. In this study, anticancer activities and the underlying mechanisms of SBC action were investigated and compared these with those of SAC using human gastric cancer SGC-7901 cells. SBC significantly suppressed the survival rate of SGC-7901 cells in a concentration- and time-dependent manner, and the inhibitory activities of SBC were stronger than those of SAC. Flow cytometry revealed that SBC induced G2-phase arrest and apoptosis in SGC-7901 cells. Typical apoptotic morphological changes were observed by Hoechst 33258 dye assay. SBC-treatment dramatically induced the dissipation of mitochondrial membrane potential (Δψm), and enhanced the enzymatic activities of caspase-9 and caspase-3 whilst hardly affecting caspase-8 activity. Furthermore, Western blotting indicated that SBC-induced apoptosis was accompanied by up-regulation of the expression of p53, Bax and the down-regulation of Bcl-2. Taken together, this study suggested that SBC exerts cytotoxic activity involving activation of mitochondrial-dependent apoptosis through p53 and Bax/Bcl-2 pathways in human gastric cancer SGC-7901 cells. PMID:24377536

  14. Staphylococcal Enterotoxin O Exhibits Cell Cycle Modulating Activity

    PubMed Central

    Hodille, Elisabeth; Alekseeva, Ludmila; Berkova, Nadia; Serrier, Asma; Badiou, Cedric; Gilquin, Benoit; Brun, Virginie; Vandenesch, François; Terman, David S.; Lina, Gerard

    2016-01-01

    Maintenance of an intact epithelial barrier constitutes a pivotal defense mechanism against infections. Staphylococcus aureus is a versatile pathogen that produces multiple factors including exotoxins that promote tissue alterations. The aim of the present study is to investigate the cytopathic effect of staphylococcal exotoxins SEA, SEG, SEI, SElM, SElN and SElO on the cell cycle of various human cell lines. Among all tested exotoxins only SEIO inhibited the proliferation of a broad panel of human tumor cell lines in vitro. Evaluation of a LDH release and a DNA fragmentation of host cells exposed to SEIO revealed that the toxin does not induce necrosis or apoptosis. Analysis of the DNA content of tumor cells synchronized by serum starvation after exposure to SEIO showed G0/G1 cell cycle delay. The cell cycle modulating feature of SEIO was confirmed by the flow cytometry analysis of synchronized cells exposed to supernatants of isogenic S. aureus strains wherein only supernatant of the SElO producing strain induced G0/G1 phase delay. The results of yeast-two-hybrid analysis indicated that SEIO’s potential partner is cullin-3, involved in the transition from G1 to S phase. In conclusion, we provide evidence that SEIO inhibits cell proliferation without inducing cell death, by delaying host cell entry into the G0/G1 phase of the cell cycle. We speculate that this unique cell cycle modulating feature allows SEIO producing bacteria to gain advantage by arresting the cell cycle of target cells as part of a broader invasive strategy. PMID:27148168

  15. Staphylococcal Enterotoxin O Exhibits Cell Cycle Modulating Activity.

    PubMed

    Hodille, Elisabeth; Alekseeva, Ludmila; Berkova, Nadia; Serrier, Asma; Badiou, Cedric; Gilquin, Benoit; Brun, Virginie; Vandenesch, François; Terman, David S; Lina, Gerard

    2016-01-01

    Maintenance of an intact epithelial barrier constitutes a pivotal defense mechanism against infections. Staphylococcus aureus is a versatile pathogen that produces multiple factors including exotoxins that promote tissue alterations. The aim of the present study is to investigate the cytopathic effect of staphylococcal exotoxins SEA, SEG, SEI, SElM, SElN and SElO on the cell cycle of various human cell lines. Among all tested exotoxins only SEIO inhibited the proliferation of a broad panel of human tumor cell lines in vitro. Evaluation of a LDH release and a DNA fragmentation of host cells exposed to SEIO revealed that the toxin does not induce necrosis or apoptosis. Analysis of the DNA content of tumor cells synchronized by serum starvation after exposure to SEIO showed G0/G1 cell cycle delay. The cell cycle modulating feature of SEIO was confirmed by the flow cytometry analysis of synchronized cells exposed to supernatants of isogenic S. aureus strains wherein only supernatant of the SElO producing strain induced G0/G1 phase delay. The results of yeast-two-hybrid analysis indicated that SEIO's potential partner is cullin-3, involved in the transition from G1 to S phase. In conclusion, we provide evidence that SEIO inhibits cell proliferation without inducing cell death, by delaying host cell entry into the G0/G1 phase of the cell cycle. We speculate that this unique cell cycle modulating feature allows SEIO producing bacteria to gain advantage by arresting the cell cycle of target cells as part of a broader invasive strategy. PMID:27148168

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

    PubMed Central

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

    2013-01-01

    Natural killer (NK) cell malignancies, particularly aggressive NK cell leukaemias and lymphomas, have poor prognoses. Although recent regimens with L-asparaginase substantially improved outcomes, novel therapeutic approaches are still needed to enhance clinical response. Resveratrol, a naturally occurring polyphenol, has been extensively studied for its anti-inflammatory, cardioprotective and anti-cancer activities. In this study, we investigated the potential anti-tumour activities of resveratrol against the NK cell lines KHYG-1, NKL, NK-92 and NK-YS. Resveratrol induced robust G0/G1 cell cycle arrest, significantly suppressed cell proliferation and induced apoptosis in a dose- and time-dependent manner for all four cell lines. In addition, resveratrol suppressed constitutively active STAT3 in all the cell lines and inhibited JAK2 phosphorylation but had no effect on other upstream mediators of STAT3 activation, such as PTEN, TYK2, and JAK1. Resveratrol also induced downregulation of the anti-apoptotic proteins MCL1 and survivin, two downstream effectors of the STAT3 pathway. Finally, resveratrol induced synergistic effect on the apoptotic and antiproliferative activities of L-asparaginase against KHYG-1, NKL and NK-92 cells. These results suggest that resveratrol may have therapeutic potential against NK cell malignancies. Furthermore, our finding that resveratrol is a bonafide JAK2 inhibitor extends its potential benefits to other diseases with dysregulated JAK2 signaling. PMID:23372833

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

    SciTech Connect

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

    2006-02-24

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

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

    PubMed Central

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

    2015-01-01

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

  19. T. gondii RP Promoters & Knockdown Reveal Molecular Pathways Associated with Proliferation and Cell-Cycle Arrest

    PubMed Central

    Hutson, Samuel L.; Mui, Ernest; Kinsley, Karen; Witola, William H.; Behnke, Michael S.; El Bissati, Kamal; Muench, Stephen P.; Rohrman, Brittany; Liu, Susan R.; Wollmann, Robert; Ogata, Yuko; Sarkeshik, Ali; Yates, John R.; McLeod, Rima

    2010-01-01

    Molecular pathways regulating rapid proliferation and persistence are fundamental for pathogens but are not elucidated fully in Toxoplasma gondii. Promoters of T. gondii ribosomal proteins (RPs) were analyzed by EMSAs and ChIP. One RP promoter domain, known to bind an Apetela 2, bound to nuclear extract proteins. Promoter domains appeared to associate with histone acetyl transferases. To study effects of a RP gene's regulation in T. gondii, mutant parasites (Δrps13) were engineered with integration of tetracycline repressor (TetR) response elements in a critical location in the rps13 promoter and transfection of a yellow fluorescent-tetracycline repressor (YFP-TetR). This permitted conditional knockdown of rps13 expression in a tightly regulated manner. Δrps13 parasites were studied in the presence (+ATc) or absence of anhydrotetracycline (-ATc) in culture. -ATc, transcription of the rps13 gene and expression of RPS13 protein were markedly diminished, with concomitant cessation of parasite replication. Study of Δrps13 expressing Myc-tagged RPL22, -ATc, showed RPL22 diminished but at a slower rate. Quantitation of RNA showed diminution of 18S RNA. Depletion of RPS13 caused arrest of parasites in the G1 cell cycle phase, thereby stopping parasite proliferation. Transcriptional differences ±ATc implicate molecules likely to function in regulation of these processes. In vitro, -ATc, Δrps13 persists for months and the proliferation phenotype can be rescued with ATc. In vivo, however, Δrps13 could only be rescued when ATc was given simultaneously and not at any time after 1 week, even when L-NAME and ATc were administered. Immunization with Δrps13 parasites protects mice completely against subsequent challenge with wildtype clonal Type 1 parasites, and robustly protects mice against wildtype clonal Type 2 parasites. Our results demonstrate that G1 arrest by ribosomal protein depletion is associated with persistence of T. gondii in a model system in vitro and

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

    SciTech Connect

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

    2013-05-10

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

  1. Viscum Album Var Hot Water Extract Mediates Anti-cancer Effects through G1 Phase Cell Cycle Arrest in SK-Hep1 Human Hepatocarcinoma cells.

    PubMed

    dela Cruz, Joseph Flores; Kim, Yeon Soo; Lumbera, Wenchie Marie Lara; Hwang, Seong Gu

    2015-01-01

    Viscum album var (VAV) also known as mistletoe, has long been categorized as a traditional herbal medicine in Asia. In addition to its immunomodulating activities, mistletoe has also been used in the treatment of chronic hepatic disorders in China and Korea. There are numerous reports showing that VAV possesses anti-cancer effects, however influence on human hepatocarcinoma has never been elucidated. In the present study, hot water extracts of VAV was evaluated for its potential anti-cancer effect in vitro. SK-Hep1 cells were treated with VAV (50-400 ug/ml) for both 24 and 48 hours then cell viability was measured by cell counting kit-8 (CCK-8). Flow cytometry analysis was used to measure the proportion of SK-Hep1 in the different stages of cell cycle. RT-PCR and Western blot analysis were conducted to measure expression of cell cycle arrest related genes and proteins respectively. VAV dose dependently inhibited the proliferation of SK-Hep1 cells without any cytotoxicity with normal Chang liver cell (CCL-13). Flow cytometry analysis showed that VAV extract inhibited the cell cycle of SK-Hep1 cells via G1 phase arrest. RT-PCR and Western blot analysis both revealed that cyclin dependent kinase 2 (Cdk2) and cyclin D1 gene expression were significantly down regulated while p21 was upregulated dose dependently by VAV treatment. Combined down regulation of Cdk2, Cyclin D1 and up regulation of p21 can result in cell death. These results indicate that VAV showed evidence of anti-cancer activity through G1 phase cell cycle arrest in SK-Hep1 cells. PMID:26434853

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

    PubMed

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

    2015-11-10

    Radiotherapy in children causes debilitating cognitive decline, partly linked to impaired neurogenesis. Irradiation targets primarily cancer cells but also endogenous neural stem/progenitor cells (NSPCs) leading to cell death or cell cycle arrest. Here we evaluated the effects of lithium on proliferation, cell cycle and DNA damage after irradiation of young NSPCs in vitro.NSPCs were treated with 1 or 3 mM LiCl and we investigated proliferation capacity (neurosphere volume and bromodeoxyuridine (BrdU) incorporation). Using flow cytometry, we analysed apoptosis (annexin V), cell cycle (propidium iodide) and DNA damage (γH2AX) after irradiation (3.5 Gy) of lithium-treated NSPCs.Lithium increased BrdU incorporation and, dose-dependently, the number of cells in replicative phase as well as neurosphere growth. Irradiation induced cell cycle arrest in G1 and G2/M phases. Treatment with 3 mM LiCl was sufficient to increase NSPCs in S phase, boost neurosphere growth and reduce DNA damage. Lithium did not affect the levels of apoptosis, suggesting that it does not rescue NSPCs committed to apoptosis due to accumulated DNA damage.Lithium is a very promising candidate for protection of the juvenile brain from radiotherapy and for its potential to thereby improve the quality of life for those children who survive their cancer. PMID:26397227

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

    PubMed Central

    Omelyanenko, Anna; Andäng, Michael; Delle, Ulla; Elmroth, Kecke; Blomgren, Klas

    2015-01-01

    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. PMID:26397227

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed

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

    2016-02-01

    Bcl-2 protein has been contributed with number of genes which are involved in oncogenesis. Among the many targets of Bcl-2, NFκB have potential role in induction of cell cycle arrest. Curcumin has potential therapeutic effects against breast cancer through multiple signaling pathways. In this study, we investigated the role of curcumin in induction of cell cycle arrest via regulating of NFκB and polyamine biosynthesis in wt and Bcl-2+ MCF-7 cells. To examine the effect of curcumin on cell cycle regulatory proteins, PI3K/Akt, NFκB pathways and polyamine catabolism, we performed immunoblotting assay. In addition, cell cycle analysis was performed by flow cytometry. The results indicated that curcumin induced cell cycle arrest at G2/M phase by downregulation of cyclin B1 and Cdc2 and inhibited colony formation in MCF-7wt cells. However, Bcl-2 overexpression prevented the inhibition of cell cycle associated proteins after curcumin treatment. The combination of LY294002, PI3K inhibitor, and curcumin induced cell cycle arrest by decreasing CDK4, CDK2 and cyclin E2 in Bcl-2+ MCF-7 cells. Moreover, LY294002 further inhibited the phosphorylation of Akt in Bcl-2+ MCF-7 cells. Curcumin could suppress the nuclear transport of NFκB through decreasing the interaction of P-IκB-NFκB. The combination of wedelolactone, NFκB inhibitor, and curcumin acted different on SSAT expression in wt MCF-7 and Bcl-2+ MCF-7 cells. NFκB inhibition increased the SSAT after curcumin treatment in Bcl-2 overexpressed MCF-7 cells. Inhibition of NFκB activity as well as suppression of ROS generation with NAC resulted in the partial relief of cells from G2/M checkpoint after curcumin treatment in wt MCF-7 cells. In conclusion, the potential role of curcumin in induction of cell cycle arrest is related with NFκB-regulated polyamine biosynthesis. PMID:26796279

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

    PubMed Central

    Duangmano, Suwit; Sae-lim, Phorntip; Suksamrarn, Apichart; Patmasiriwat, Pimpicha; Domann, Frederick E.

    2012-01-01

    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 137Cs 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. PMID:22690217

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

    PubMed Central

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

    2015-01-01

    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. PMID:26503893

  8. In vitro cell cycle arrest induced by using artificial DNA templates.

    PubMed Central

    Kornbluth, S; Smythe, C; Newport, J W

    1992-01-01

    In cell extracts of Xenopus eggs which oscillate between S and M phases of the cell cycle, the onset of mitosis is blocked by the presence of incompletely replicated DNA. In this report, we show that several artificial DNA templates (M13 single-stranded DNA and double-stranded plasmid DNA) can trigger this feedback pathway, which inhibits mitosis. Single-stranded M13 DNA is much more effective than double-stranded plasmid DNA at inhibiting the onset of mitosis. Furthermore, we have shown that low levels of M13 single-stranded DNA and high levels of double-stranded plasmid DNA can elevate the tyrosine kinase activity responsible for phosphorylating p34cdc2, thereby inactivating maturation-promoting factor and inhibiting entry into mitosis. This constitutes a simplified system with which to study the signal transduction pathway from the DNA template to the tyrosine kinase responsible for inhibiting p34cdc2 activity. Images PMID:1320197

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

    PubMed Central

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

    2015-01-01

    Ovarian cancer is one of the most common causes of mortality among all cancers in females and is the primary cause of mortality from gynecological malignancies. The objective of the current research work was to evaluate a naturally occurring sesquiterpene-δ-Cadinene for its antiproliferative and apoptotic effects on human ovary cancer (OVCAR-3) cells. We also demonstrated the effect of δ-Cadinene on cell cycle phase distribution, intracellular damage and caspase activation. Sulforhodamine B (SRB) assay was used to evaluate the antiproliferative effect of δ-cadinene on OVCAR-3 cells. Cellular morphology after δ-cadinene treatment was demonstrated by inverted phase contrast microscopy, fluorescence microscopy and transmission electron microscopy. Flow cytometry was used to analyze the effect of δ-cadinene on cell cycle phase distribution and apoptosis using propidium iodide and Annexin V-fluorescein isothiocyanate (FITC)/PI kit. The results revealed that δ-cadinene induced dose-dependent as well as time-dependent growth inhibitory effects on OVACR-3 cell line. δ-cadinene also induced cell shrinkage, chromatin condensation and nuclear membrane rupture which are characteristic of apoptosis. Treatment with different doses of δ-cadinene also led to cell cycle arrest in sub-G1 phase which showed dose-dependence. Western blotting assay revealed that δ-cadinene led to activation of caspases in OVCAR-3 cancer cells. PARP cleavage was noticed at 50 µM dose of δ-cadinene with the advent of the cleaved 85-kDa fragment after exposure to δ-cadinene. At 100 µM, only the cleaved form of PARP was detectable. Pro-caspase-8 expression remained unaltered until 10 µM dose of δ-cadinene. However, at 50 and 100 µM dose, pro-caspase-8 expression was no longer detectable. There was a significant increase in the caspase-9 expression levels after 50 and 100 µM δ-cadinene treatments. PMID:26261482

  10. G protein-coupled receptor GPR160 is associated with apoptosis and cell cycle arrest of prostate cancer cells

    PubMed Central

    Zhou, Caihong; Dai, Xinchuan; Chen, Yi; Shen, Yanyan; Lei, Saifei; Xiao, Ting; Bartfai, Tamas; Ding, Jian; Wang, Ming-Wei

    2016-01-01

    G protein-coupled receptors (GPCRs) represent the largest membrane protein family implicated in the therapeutic intervention of a variety of diseases including cancer. Exploration of biological actions of orphan GPCRs may lead to the identification of new targets for drug discovery. This study investigates potential roles of GPR160, an orphan GPCR, in the pathogenesis of prostate cancer. The transcription levels of GPR160 in the prostate cancer tissue samples and cell lines, such as PC-3, LNCaP, DU145 and 22Rv1 cells, were significantly higher than that seen in normal prostate tissue and cells. Knockdown of GPR160 by lentivirus-mediated short hairpin RNA constructs targeting human GPR160 gene (ShGPR160) resulted in prostate cancer cell apoptosis and growth arrest both in vitro and in athymic mice. Differential gene expression patterns in PC-3 cells infected with ShGPR160 or scramble lentivirus showed that 815 genes were activated and 1193 repressed. Functional annotation of differentially expressed genes (DEGs) revealed that microtubule cytoskeleton, cytokine activity, cell cycle phase and mitosis are the most evident functions enriched by the repressed genes, while regulation of programmed cell death, apoptosis and chemotaxis are enriched significantly by the activated genes. Treatment of cells with GPR160-targeting shRNA lentiviruses or duplex siRNA oligos increased the transcription of IL6 and CASP1 gene significantly. Our data suggest that the expression level of endogenous GPR160 is associated with the pathogenesis of prostate cancer. PMID:26871479

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

    PubMed

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

    2011-08-24

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

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

    PubMed

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

    2016-02-01

    Adiponectin predominantly secreted from adipose tissue has exhibited potent anti-proliferative properties in cancer cells via modulating cell cycle and apoptosis. FoxO3A, a Forkhead box O member of the transcription factor, plays a critical role in modulating expression of genes involved in cell death and/or survival. In this study, we investigated the role of FoxO3A signaling in anti-cancer activities of adiponectin. Herein, we have shown that treatment with globular adiponectin (gAcrp) increases p27 but decreases cyclinD1 expression in human hepatoma (HepG2) and breast (MCF-7) cancer cells. Gene ablation of FoxO3A prevented gAcrp-induced increase in p27 and decreased in cyclin D1 expression, and further ameliorated cell cycle arrest by gAcrp, indicating a critical role of FoxO3A in gAcrp-induced cell cycle arrest of cancer cells. Moreover, treatment with gAcrp also induced caspase-3/7 activation and increased Fas ligand (FasL) expression in both HepG2 and MCF-7 cells. Transfection with FoxO3A siRNA inhibited gAcrp-induced caspase-3/7 activation and FasL expression, suggesting that FoxO3A signaling also plays an important role in gAcrp-induced apoptosis of cancer cells. We also found that gene silencing of AMPK prevented gAcrp-induced nuclear translocation of FoxO3A in HepG2 and MCF-7 cells. In addition, suppression of AMPK also blocked gAcrp-induced cell cycle arrest and further attenuated gAcrp-induced caspase-3/7 activation, indicating that AMPK signaling plays a pivotal role in both gAcrp-induced cell cycle arrest and apoptosis via acting as an upstream signaling of FoxO3A. Taken together, our findings demonstrated that AMPK/FoxO3A axis plays a cardinal role in anti-proliferative effect of adiponectin in cancer cells. PMID:26089158

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

    PubMed

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

    2016-06-01

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

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

    ERIC Educational Resources Information Center

    Scherer, Yvette D.

    2014-01-01

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

  15. Isodeoxyelephantopin from Elephantopus scaber (Didancao) induces cell cycle arrest and caspase-3-mediated apoptosis in breast carcinoma T47D cells and lung carcinoma A549 cells

    PubMed Central

    2014-01-01

    Background Isodeoxyelephantopin (IDOE) isolated from Elephantopus scaber L. (Didancao) is used in Chinese medicine for the treatment of some types of cancer. The anti-cancer mechanism of IDOE remains unclear. This study aims to investigate the antiproliferative activity of IDOE on breast carcinoma T47D cells and lung carcinoma A549 cells. Methods The growth inhibitory effects of IDOE on breast carcinoma T47D cells, lung carcinoma A549 cells, and normal lymphocytes were evaluated by the MTT assay. Morphological analysis of apoptosis induction was performed by acridine orange/ethidium bromide dual-staining and Hoechst 33342 nuclear staining. The cell cycle profile, caspase-3 expression, and annexin V staining were evaluated by flow cytometry. Results IDOE inhibited the growth of A549 and T47D cells in a dose- and time-dependent manner with IC50 values of 10.46 and 1.3 μg/mL, respectively. IDOE was not significantly toxic to normal lymphocytes. The cells became detached from the monolayer and rounded up, had fragmented nuclei and condensed chromatin, and the numbers of apoptotic cells increased (P = 0.0003). IDOE-induced cell death was associated with activated caspase-3 expression followed by cell cycle arrest at G2/M phase. Conclusions IDOE inhibited the proliferation of breast cancer cells and lung carcinoma cells and induced caspase-3-mediated apoptosis and cell cycle arrest in the treated cells. PMID:24742378

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

    PubMed

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

    2010-02-01

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

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

    PubMed Central

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

    2016-01-01

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

  18. Xanthatin induces G2/M cell cycle arrest and apoptosis in human gastric carcinoma MKN-45 cells.

    PubMed

    Zhang, Lei; Tao, Li; Ruan, Junshan; Li, Weidong; Wu, Yu; Yan, Linggeng; Zhang, Feng; Fan, Fangtian; Zheng, Shizhong; Wang, Aiyun; Lu, Yin

    2012-06-01

    Xanthatin, a natural bioactive compound of sesquiterpene lactones, was isolated and purified from air-dried aerial part of Xanthium sibiricum Patrin ex Widder. In the present study, we demonstrated the significant antiproliferative and proapoptotic effects of xanthatin on human gastric carcinoma MKN-45 cells. MTS assay showed that xanthatin produced obvious cytotoxicity in MKN-45 cells with IC50 values of 18.6, 9.3, and 3.9 µM for 12, 24, and 48 h, respectively. Results of flow cytometry analysis indicated that the antiproliferative activity induced by xanthatin might be executed via G2/M cell cycle arrest and proapoptosis in MKN-45 cells. Western blot analysis elucidated that: a) xanthatin downregulated expression of Chk1 and Chk2 and phosphorylation of CDC2, which are known as key G2/M transition regulators; b) xanthatin increased p53 activation, decreased the bcl-2/bax ratio and the levels of downstream procaspase-9 and procaspase-3, which are key regulators in the intrinsic apoptosis pathway; c) xanthatin blocked phosphorylation of NF-κB (p65 subunit) and of IκBα, which might contribute to its proapoptotic effects on MKN-45 cells. In conclusion, our results suggest that xanthatin may have therapeutic potential against human gastric carcinoma. PMID:22532019

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

    PubMed Central

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

    2016-01-01

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

  20. Pheromone-Dependent G1 Cell Cycle Arrest Requires Far1 Phosphorylation, but May Not Involve Inhibition of Cdc28-Cln2 Kinase, In Vivo

    PubMed Central

    Gartner, Anton; Jovanović, Alexandra; Jeoung, Doo-Il; Bourlat, Sarah; Cross, Frederick R.; Ammerer, Gustav

    1998-01-01

    In yeast, the pheromone α-factor acts as an antiproliferative factor that induces G1 arrest and cellular differentiation. Previous data have indicated that Far1, a factor dedicated to pheromone-induced cell cycle arrest, is under positive and negative posttranslational regulation. Phosphorylation by the pheromone-stimulated mitogen-activated protein (MAP) kinase Fus3 has been thought to enhance the binding of Far1 to G1-specific cyclin-dependent kinase (Cdk) complexes, thereby inhibiting their catalytic activity. Cdk-dependent phosphorylation events were invoked to account for the high instability of Far1 outside early G1 phase. To confirm any functional role of Far1 phosphorylation, we undertook a systematic mutational analysis of potential MAP kinase and Cdk recognition motifs. Two putative phosphorylation sites that strongly affect Far1 behavior were identified. A change of serine 87 to alanine prevents the cell cycle-dependent degradation of Far1, causing enhanced sensitivity to pheromone. In contrast, threonine 306 seems to be an important recipient of an activating modification, as substitutions at this position abolish the G1 arrest function of Far1. Only the phosphorylated wild-type Far1 protein, not the T306-to-A substitution product, can be found in stable association with the Cdc28-Cln2 complex. Surprisingly, Far1-associated Cdc28-Cln2 complexes are at best moderately inhibited in immunoprecipitation kinase assays, suggesting unconventional inhibitory mechanisms of Far1. PMID:9632750

  1. Curcumin Promotes Cell Cycle Arrest and Inhibits Survival of Human Renal Cancer Cells by Negative Modulation of the PI3K/AKT Signaling Pathway.

    PubMed

    Zhang, Hao; Xu, Weili; Li, Baolin; Zhang, Kai; Wu, Yudong; Xu, Haidong; Wang, Junyong; Zhang, Jun; Fan, Rui; Wei, Jinxing

    2015-12-01

    Curcumin possesses anti-cancer effects. In the current study, we tested the effect of curcumin on cell proliferation, viability, apoptosis, cell cycle phases, and activation of the PI3K/Akt pathway in the renal cell carcinoma (RCC) cell line RCC-949. We observed that cell proliferation and viability were markedly inhibited by curcumin, while cell apoptosis was promoted. The latter effect was associated with increased expression of Bcl-2 and diminished expression of Bax (both: mRNA and protein). The cells treated with curcumin increasingly went into cell cycle arrest, which was likely mediated by diminished expression of cyclin B1, as seen in curcumin-treated cells. In addition, curcumin decreased activation of the PI3K/AKT signaling pathway. In conclusion, our results demonstrate that curcumin exerts anti-cancer effects by negative modulation of the PI3K/AKT signaling pathway and may represent a promising new drug to treat RCC. PMID:27259310

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

    PubMed Central

    Pfeuty, Benjamin

    2012-01-01

    Transitions between consecutive phases of the eukaryotic cell cycle are driven by the catalytic activity of selected sets of cyclin-dependent kinases (Cdks). Yet, their occurrence and precise timing is tightly scheduled by a variety of means including Cdk association with inhibitory/adaptor proteins (CKIs). Here we focus on the regulation of G1-phase duration by the end of which cells of multicelled organisms must decide whether to enter S phase or halt, and eventually then, differentiate, senesce or die to obey the homeostatic rules of their host. In mammalian cells, entry in and progression through G1 phase involve sequential phosphorylation and inactivation of the retinoblastoma Rb proteins, first, by cyclin D-Cdk4,6 with the help of CKIs of the Cip/Kip family and, next, by the cyclin E-Cdk2 complexes that are negatively regulated by Cip/Kip proteins. Using a dynamical modeling approach, we show that the very way how the Rb and Cip/Kip regulatory modules interact differentially with cyclin D-Cdk4,6 and cyclin E-Cdk2 provides to mammalian cells a powerful means to achieve an exquisitely-sensitive control of G1-phase duration and fully reversible G1 arrests. Consistently, corruption of either one of these two modules precludes G1 phase elongation and is able to convert G1 arrests from reversible to irreversible. This study unveils fundamental design principles of mammalian G1-phase regulation that are likely to confer to mammalian cells the ability to faithfully control the occurrence and timing of their division process in various conditions. PMID:22558136

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

    PubMed

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

    2015-09-01

    Nimbolide is a tetranortriterpenoid isolated from the leaves and flowers of Azadirachta indica which has been shown to exhibit anticancer, antioxidant, anti-inflammatory, and anti-invasive properties in a variety of cancer cells. However, the anti-tumor effect on human renal cell carcinoma (RCC) cells is unknown. In this study, we found that nimbolide treatment had a cytotoxic effect on 786-O and A-498 RCC cells in a dose-dependent manner. According to flow cytometric analysis, nimbolide treatment resulted in G2/M arrest in 786-O and A-498 cells accompanied with an increase in the phosphorylation status of p53, cdc2, cdc25c, and decreased expressions of cyclin A, cyclin B, cdc2, and cdc25c. Nimbolide also caused DNA damage in a dose-dependent manner as determined by comet assay and measurement of γ-H2AX. In addition, apoptotic cells were observed in an Annexin V-FITC/propidium iodide double-stained assay. The activities of caspase-3, -9, and poly ADP-ribose polymerase (PARP) were increased, and the expression of pro-caspase-8 was decreased in nimbolide-treated 786-O and A-498 cells. Western blot analysis revealed that the levels of intrinsic-related apoptotic proteins Bax and extrinsic-related proteins (DR5, CHOP) were significantly increased in nimbolide-treated 786-O and A-498 cells. In addition, the expressions of Bcl-2 and Mcl-1 were decreased in 786-O and A-498 cells after nimbolide treatment. We conclude that nimbolide can inhibit the growth of human RCC cells by inducing G2/M phase arrest by modulating cell cycle-related proteins and cell apoptosis by regulating intrinsic and extrinsic caspase signaling pathways. Nimbolide may be a promising therapeutic strategy for the treatment of RCC. PMID:25916210

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

    PubMed

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

    2010-06-01

    Limonoids from the neem tree (Azadirachta indica) have attracted considerable research attention in recent years owing to their potent antioxidant and anti-proliferative effects. The present study was designed to investigate the cellular and molecular mechanisms by which azadirachtin and nimbolide exert cytotoxic effects in the human cervical cancer (HeLa) cell line. Both azadirachtin and nimbolide significantly suppressed the viability of HeLa cells in a dose-dependent manner by inducing cell cycle arrest at G0/G1 phase accompanied by p53-dependent p21 accumulation and down-regulation of the cell cycle regulatory proteins cyclin B, cyclin D1 and PCNA. Characteristic changes in nuclear morphology, presence of a subdiploid peak and annexin-V staining pointed to apoptosis as the mode of cell death. Increased generation of reactive oxygen species with decline in the mitochondrial transmembrane potential and release of cytochrome c confirmed that the neem limonoids transduced the apoptotic signal via the mitochondrial pathway. Altered expression of the Bcl-2 family of proteins, inhibition of NF-kappaB activation and over-expression of caspases and survivin provide compelling evidence that azadirachtin and nimbolide induce a shift of balance toward a pro-apoptotic phenotype. Antioxidants such as azadirachtin and nimbolide that can simultaneously arrest the cell cycle and target multiple molecules involved in mitochondrial apoptosis offer immense potential as anti-cancer therapeutic drugs. PMID:20429769

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

    PubMed Central

    Arora, Shagun; Tandon, Simran

    2014-01-01

    Achyranthes aspera (AA) has been used traditionally for the cure of various disorders. However, the action of root extracts of AA as anticancer agent and its cellular mechanism remain unclear. The aim was to screen the antitumor effect of ethanolic (EAA) and aqueous (AAA) root extracts on the growth of colon cancer COLO-205 cells by testing their cytotoxicity, followed by their effect on clonogenicity, migration, and induction of apoptosis. Mechanisms leading to apoptosis and cell cycle arrest were also investigated by expression studies of caspase-9, caspase-3, Bax, Bcl-2, p16, p21, and p27 genes, followed by flow cytometric analysis for cell cycle distribution. Cytotoxicity screening of AA extracts indicated greater cytotoxic activity of AAA extract against COLO-205 cells. A series of events marked by apoptosis revealed loss of cell viability, chromatin condensation, and DNA fragmentation in AAA treated cells to a greater extent. The mRNA expression levels of caspase-9, caspase-3, Bax, p16, p21, and p27 were markedly increased in the AAA treated cells, along with decreased Bcl-2 expression. The cell cycle arrest at S phase was detected by flow cytometric analysis after treatment with AAA. Overall the study signifies the aqueous extracts as a promising therapeutic candidate against cancer. PMID:25401123

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed Central

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

    2015-01-01

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

  8. Cellular Effect of Curcumin and Citral Combination on Breast Cancer Cells: Induction of Apoptosis and Cell Cycle Arrest

    PubMed Central

    Thakkar, Vasudev R.; Patel, Jagdish S.

    2015-01-01

    Purpose The unmanageable side effects caused by current chemotherapy regimens to treat cancer are an unresolved problem. Although many phytonutrients are useful as chemoprevention without side effects, their effects are slower and smaller than conventional chemotherapy. In the present work, we examined the cumulative effect of two phytonutrients, curcumin and citral, on breast cancer cell lines and compared their effect with the known chemotherapy regimen of cyclophosphamide, methotrexate, and 5-fluorouracil. Methods Using cultured breast cancer and normal epithelial cells, the cytotoxic and apoptotic effect of curcumin and citral was evaluated in vitro. The synergistic effect of curcumin and citral was calculated by a combination index study using the method by Chou and Talalay. Cell death pathways and mechanisms were analyzed by measuring intracellular reactive oxygen species (ROS) and apoptotic protein levels. Results Curcumin and citral caused dose and time dependent cell death and showed a synergistic effect at effective concentration EC50 and above concentrations in breast cancer cells without disturbing normal breast epithelial cells. With combination curcumin and citral treatment, apoptosis induction and cell cycle arrest at G0/G1 phase in breast cancer cells were observed. Curcumin and citral generated ROS and activated p53 and poly (ADP-ribose) polymerase-1 mediated apoptotic pathways. Conclusion The results of this study suggest that curcumin and citral in combination may be a useful therapeutic intervention for breast cancer. PMID:26472972

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

    PubMed Central

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

    2016-01-01

    Activating enhancer-binding protein (AP)-4 is a member of the basic helix-loop-helix transcription factors, and is involved in tumor biology. However, the role of AP-4 in human lung cancer remains to be fully elucidated. In the present study, the expression of AP-4 in human lung cancer tissues and cells was investigated by reverse transcription-quantitative polymerase chain reaction, and it was observed that the level of AP-4 was increased in tumor tissues and cells compared with their normal counterparts. AP-4 expression was knocked down by transfection with a specific small interfering RNA (siRNA) in lung cancer cells, and this indicated that siRNA-mediated silencing of AP-4 inhibited cell proliferation, arrested the cell cycle at the G0/G1 phase and induced apoptosis by modulating the expression of p21 and cyclin D1. The results of the present study suggest that AP-4 may be an oncoprotein that has a significant role in lung cancer, and that siRNA-mediated silencing of AP-4 may have therapeutic potential as a strategy for the treatment of lung cancer. PMID:27313685

  10. Knockdown of HNRNPA1 inhibits lung adenocarcinoma cell proliferation through cell cycle arrest at G0/G1 phase.

    PubMed

    Liu, Xianxun; Zhou, Yan; Lou, Yuqing; Zhong, Hua

    2016-02-01

    Heterogeneous nuclear ribonucleoprotein A1 (HNRNPA1), a member of heterogeneous nuclear ribonucleoprotein family in actively growing mammalian cells, is involved in a variety of RNA-related processes. HNRNPA1 can enhance the degradation of inhibitory subunit of nuclear factor κ B alpha (IκBα) and lengthen the telomeres. Recently, it is reported that HNRNPA1 is aberrantly expressed in varied tumors. In this study we found HNRNPA1 protein overexpressed in lung cancer tissues. To explore the exact role of HNRNPA1 in lung cancers, we carried out a loss of function analysis of HNRNPA1 in A549 lung cancer cells by RNA interference (RNAi). The results demonstrated that knockdown of HNRNPA1 inhibited cell viability and colony formation of lung cancer cells and arrested cell cycle in G0/G1 phase. Our study suggested that HNRNPA1 might play an important role in lung adenocarcinoma cells and provided a foundation for further study into the potential of HNRNPA1 for lung cancer therapy. PMID:26581508

  11. An Aqueous Extract of Fagonia cretica Induces DNA Damage, Cell Cycle Arrest and Apoptosis in Breast Cancer Cells via FOXO3a and p53 Expression

    PubMed Central

    Lam, Matt; Carmichael, Amtul R.; Griffiths, Helen R.

    2012-01-01

    Background Plants have proved to be an important source of anti-cancer drugs. Here we have investigated the cytotoxic action of an aqueous extract of Fagonia cretica, used widely as a herbal tea-based treatment for breast cancer. Methodology/Principal Findings Using flow cytometric analysis of cells labeled with cyclin A, annexin V and propidium iodide, we describe a time and dose-dependent arrest of the cell cycle in G0/G1 phase of the cell cycle and apoptosis following extract treatment in MCF-7 (WT-p53) and MDA-MB-231 (mutant-p53) human breast cancer cell lines with a markedly reduced effect on primary human mammary epithelial cells. Analysis of p53 protein expression and of its downstream transcription targets, p21 and BAX, revealed a p53 associated growth arrest within 5 hours of extract treatment and apoptosis within 24 hours. DNA double strand breaks measured as γ-H2AX were detected early in both MCF-7 and MDA-MB-231 cells. However, loss of cell viability was only partly due to a p53-driven response; as MDA-MB-231 and p53-knockdown MCF-7 cells both underwent cell cycle arrest and death following extract treatment. p53-independent growth arrest and cytotoxicity following DNA damage has been previously ascribed to FOXO3a expression. Here, in MCF-7 and MDA-MB-231 cells, FOXO3a expression was increased significantly within 3 hours of extract treatment and FOXO3 siRNA reduced the extract-induced loss of cell viability in both cell lines. Conclusions/Significance Our results demonstrate for the first time that an aqueous extract of Fagonia cretica can induce cell cycle arrest and apoptosis via p53-dependent and independent mechanisms, with activation of the DNA damage response. We also show that FOXO3a is required for activity in the absence of p53. Our findings indicate that Fagonia cretica aqueous extract contains potential anti-cancer agents acting either singly or in combination against breast cancer cell proliferation via DNA damage-induced FOXO3a and p53

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

    SciTech Connect

    Cheng, Jing; Du, Yi-Fang; Xiao, Zhi-Yi; Pan, Li-Li; Li, Wei; Huan, Lin; Gong, Zhu-Nan; Wei, Shao-Hua; Huang, Shi-Qian; Xun, Wei; Zhang, Yi; Chang, Lei-Lei; Xie, Meng-Yu; Ao, Gui-Zhen; Cai, Jie; Qiu, Ting; Wu, Hao; Sun, Ting; Xu, Guang-Lin

    2014-01-01

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

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

    PubMed

    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. PMID:9527023

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

    PubMed Central

    2013-01-01

    Background Glioma stem cells in the quiescent state are resistant to clinical radiation therapy. An almost inevitable glioma recurrence is due to the persistence of these cells. The high linear energy transfer associated with boron neutron capture therapy (BNCT) could kill quiescent and proliferative cells. Methods The present study aimed to evaluate the effects of BNCT on glioma stem/progenitor cells in vitro. The damage induced by BNCT was assessed using cell cycle progression, apoptotic cell ratio and apoptosis-associated proteins expression. Results The surviving fraction and cell viability of glioma stem/progenitor cells were decreased compared with differentiated glioma cells using the same boronophenylalanine pretreatment and the same dose of neutron flux. BNCT induced cell cycle arrest in the G2/M phase and cell apoptosis via the mitochondrial pathway, with changes in the expression of associated proteins. Conclusions Glioma stem/progenitor cells, which are resistant to current clinical radiotherapy, could be effectively killed by BNCT in vitro via cell cycle arrest and apoptosis using a prolonged neutron irradiation, although radiosensitivity of glioma stem/progenitor cells was decreased compared with differentiated glioma cells when using the same dose of thermal neutron exposure and boronophenylalanine pretreatment. Thus, BNCT could offer an appreciable therapeutic advantage to prevent tumor recurrence, and may become a promising treatment in recurrent glioma. PMID:23915425

  15. Hericium erinaceus polysaccharide-protein HEG-5 inhibits SGC-7901 cell growth via cell cycle arrest and apoptosis.

    PubMed

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

    2015-05-01

    HEG-5 is a novel polysaccharide-protein purified from the fermented mycelia of Hericium erinaceus CZ-2. The present study aims to investigate the effects of HEG-5 on proliferation, cell cycle and apoptosis of human gastric cancer cells SGC-7901. Here, we first uncover that HEG-5 significantly inhibited the proliferation and colony formation of SGC-7901 cells by promoting apoptosis and cell cycle arrest at S phase. RT-PCR and Western blot analysis suggested that HEG-5 could decrease the expressions of Bcl2, PI3K and AKT1, while increase the expressions of Caspase-8, Caspase-3, p53, CDK4, Bax and Bad. These findings indicated that the Caspase-8/-3-dependent, p53-dependent mitochondrial-mediated and PI3k/Akt signaling pathways involved in the molecular events of HEG-5 induced apoptosis and cell cycle arrest. Thus, our study provides in vitro evidence that HEG-5 may be taken as a potential candidate for treating gastric cancer. PMID:25703932

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

    PubMed

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

    2016-01-01

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

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

    PubMed Central

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

    2014-01-01

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

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

    PubMed

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

    2011-11-01

    Honokiol is a plant lignan isolated from bark and seed cones of Magnolia officinalis. Recent studies from our laboratory indicated that honokiol pretreatment decreased ultraviolet B-induced skin cancer development in SKH-1 mice. The aim of the present investigation was to study the effects of honokiol on human epidermoid squamous carcinoma A431 cells and to elucidate possible mechanisms involved in preventing skin cancer. A431 cells were pretreated with different concentrations of honokiol for a specific time period and investigated for effects on apoptosis and cell cycle analysis. Treatment with honokiol significantly decreased cell viability and cell proliferation in a concentration- and time-dependent manner. Honokiol pretreatment at 50 μmol/L concentration induced G0/G1 cell cycle arrest significantly (P < 0.05) and decreased the percentage of cells in the S and G2/M phase. Honokiol down-regulated the expression of cyclin D1, cyclin D2, Cdk2, Cdk4 and Cdk6 proteins and up-regulated the expression of Cdk's inhibitor proteins p21 and p27. Pretreatment of A431 cells with honokiol leads to induction of apoptosis and DNA fragmentation. These findings indicate that honokiol provides its effects in squamous carcinoma cells by inducing cell cycle arrest at G0/G1 phase and apoptosis. PMID:21908486

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

    PubMed Central

    Carén, Helena; Stricker, Stefan H.; Bulstrode, Harry; Gagrica, Sladjana; Johnstone, Ewan; Bartlett, Thomas E.; Feber, Andrew; Wilson, Gareth; Teschendorff, Andrew E.; Bertone, Paul; Beck, Stephan; Pollard, Steven M.

    2015-01-01

    Summary 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. PMID:26607953

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

    PubMed

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

    2015-10-23

    The regulatory mechanism of granulosa cells (GCs) proliferation during the follicular development is complicated and multifactorial, which is essential for the oocyte growth and normal ovarian functions. To investigate the role of high fat diet (HFD) on the proliferation of GCs, 4-week old female mice were fed with HFD or normal control diet (NC) for 15 weeks or 20 weeks and then detected the expression level of some regulatory molecules of cell cycle and apoptosis. The abnormal ovarian morphology was observed at 20 weeks. Further mechanistic studies indicated that HFD induced-obesity caused elevated apoptotic levels in GCs of the ovaries in a time-dependent manner. Moreover, cell cycle progress was also impacted after HFD fed. The cell cycle inhibitors, p27(Kip1) and p21(Cip1), were significantly induced in the ovaries from the mice in HFD group when compared with that in the ovaries from the mice in NC group. Subsequently, the expression levels of Cyclin D1, D3 and CDK4 were also significantly influenced in the ovaries from the mice fed with HFD in a time-dependent manner. The present results suggested that HFD induced-obesity may trigger cell cycle arrest and excessive apoptosis of GCs, causing the abnormal follicular development and ovarian function failure. PMID:26399684

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

    PubMed

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

    2016-01-01

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

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

    PubMed Central

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

    2016-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

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

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

    PubMed

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

    2012-08-01

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

  5. Review of Chromium (VI) Apoptosis, Cell-Cycle-Arrest, and Carcinogenesis

    PubMed Central

    Chiu, A; Shi, J; Lee, WKP; Hill, R; Wakeman, TP; Katz, A; Xu, B; Dalal, NS; Robertson, JD; Chen, C; Chiu, N; Donehower, L

    2014-01-01

    Hexavalent chromium combines with glutathione in chloride intracellular channel carrier to form tetravalent and pentavelent chromium in plasma and organelle membranes. It also combines with NADH/NADPH to form pentavalent chromium in mitochondria. Tetravalent- and pentavalent- chromium (directly and indirectly) mediated DNA double strand breaks activate DNA damage signaling sensors: DNA-dependent-protein-kinase signals p53-dependent intrinsic mitochorndrial apoptosis, and ataxia-telangiectasia-mutated and ataxia-telangiectasia-Rad3-related signal cell-arrest for DNA repair. Tetravalent chromium may be the most potent species since it causes DNA breaks and somatic recombination, but not apoptosis. Upon further failure of apoptosis and senescence/DNA-repair, damaged cells may become immortal with loss-of-heterozygosity and genetic plasticity. PMID:20859824

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

    PubMed Central

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

    2013-01-01

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

  7. 2-Methoxy-4-vinylphenol can induce cell cycle arrest by blocking the hyper-phosphorylation of retinoblastoma protein in benzo[a]pyrene-treated NIH3T3 cells

    SciTech Connect

    Jeong, Jin Boo; Jeong, Hyung Jin

    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.

  8. Nucleolin Down-Regulation Is Involved in ADP-Induced Cell Cycle Arrest in S Phase and Cell Apoptosis in Vascular Endothelial Cells

    PubMed Central

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

    2014-01-01

    High concentration of extracellular ADP has been reported to induce cell apoptosis, but the molecular mechanisms remain not fully elucidated. In this study, we found by serendipity that ADP treatment of human umbilical vein endothelial cells (HUVEC) and human aortic endothelial cells (HAEC) down-regulated the protein level of nucleolin in a dose- and time-dependent manner. ADP treatment did not decrease the transcript level of nucloelin, suggesting that ADP might induce nucleolin protein degradation. HUVEC and HAEC expressed ADP receptor P2Y13 receptor, but did not express P2Y1 or P2Y12 receptors. However, P2Y1, 12, 13 receptor antagonists MRS2179, PSB0739, MRS2211 did not inhibit ADP-induced down-regulation of nucleolin. Moreover, MRS2211 itself down-regulated nucleolin protein level. In addition, 2-MeSADP, an agonist for P2Y1, 12 and 13 receptors, did not down-regulate nucleolin protein. These results suggested that ADP-induced nucleolin down-regulation was not due to the activation of P2Y1, 12, or 13 receptors. We also found that ADP treatment induced cell cycle arrest in S phase, cell apoptosis and cell proliferation inhibition via nucleolin down-regulation. The over-expression of nucleolin by gene transfer partly reversed ADP-induced cell cycle arrest, cell apoptosis and cell proliferation inhibition. Furthermore, ADP sensitized HUVEC to cisplatin-induced cell death by the down-regulation of Bcl-2 expression. Taken together, we found, for the first time to our knowledge, a novel mechanism by which ADP regulates cell proliferation by induction of cell cycle arrest and cell apoptosis via targeting nucelolin. PMID:25290311

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

    PubMed

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

    2014-01-01

    High concentration of extracellular ADP has been reported to induce cell apoptosis, but the molecular mechanisms remain not fully elucidated. In this study, we found by serendipity that ADP treatment of human umbilical vein endothelial cells (HUVEC) and human aortic endothelial cells (HAEC) down-regulated the protein level of nucleolin in a dose- and time-dependent manner. ADP treatment did not decrease the transcript level of nucloelin, suggesting that ADP might induce nucleolin protein degradation. HUVEC and HAEC expressed ADP receptor P2Y13 receptor, but did not express P2Y1 or P2Y12 receptors. However, P2Y1, 12, 13 receptor antagonists MRS2179, PSB0739, MRS2211 did not inhibit ADP-induced down-regulation of nucleolin. Moreover, MRS2211 itself down-regulated nucleolin protein level. In addition, 2-MeSADP, an agonist for P2Y1, 12 and 13 receptors, did not down-regulate nucleolin protein. These results suggested that ADP-induced nucleolin down-regulation was not due to the activation of P2Y1, 12, or 13 receptors. We also found that ADP treatment induced cell cycle arrest in S phase, cell apoptosis and cell proliferation inhibition via nucleolin down-regulation. The over-expression of nucleolin by gene transfer partly reversed ADP-induced cell cycle arrest, cell apoptosis and cell proliferation inhibition. Furthermore, ADP sensitized HUVEC to cisplatin-induced cell death by the down-regulation of Bcl-2 expression. Taken together, we found, for the first time to our knowledge, a novel mechanism by which ADP regulates cell proliferation by induction of cell cycle arrest and cell apoptosis via targeting nucelolin. PMID:25290311

  10. Effects of thonningianin A in natural foods on apoptosis and cell cycle arrest of HepG-2 human hepatocellular carcinoma cells.

    PubMed

    Zhang, Tian-Tian; Yang, Li; Jiang, Jian-Guo

    2015-08-01

    The anti-cancer activities of Thonningianin A on the HepG-2 human hepatocellular carcinoma cell line were evaluated by MTT assay, flow cytometry, quantitative real-time PCR and western blotting. Results showed that Thonningianin A effectively inhibited the proliferation of HepG-2 cells by inducing apoptosis, as evidenced by increase in the sub-G1 cell population, DNA fragmentation, and increase in the content of reactive oxygen species. Activation of caspase-9 and the subsequent activation of caspase-3 indicated that Thonningianin A-induced apoptosis is caspase-dependent. Thonningianin A also disrupted the mitochondrial membrane potential (Δψm) and down-regulated the Bcl-xL mRNA expression in HepG-2 cells. Thonningianin A induced cell cycle arrest by changing the cyclin D1 and CDK4 mRNA expression levels. Moreover, western blotting showed that Thonningianin A significantly down-regulated the NF-kappa-B cell survival pathway, along with up-regulation of the expression level of phosphorylated P38 and down-regulation of the expression level of phosphorylated ERK. The anti-cancer activity of Thonningianin A was confirmed by the characteristic patterns of DNA fragmentation and cell cycle arrest, suggesting that Th A is an effective antitumor ingredient in natural plant foods, and is worthy of further study. PMID:26119846

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

    PubMed Central

    CHEN, Fenglei; WANG, Nan; YANG, Diqi; WEN, Xin; MAHMOUD, Tagwa Norain; ZHOU, Dong; TANG, Keqiong; LIN, Pengfei; WANG, Aihua; JIN, Yaping

    2016-01-01

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

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

    PubMed

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

    2016-04-22

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

  13. Involvement of miR-15a in G0/G1 Phase Cell Cycle Arrest Induced by Porcine Circovirus Type 2 Replication

    PubMed Central

    Quan, Rong; Wei, Li; Zhu, Shanshan; Wang, Jing; Cao, Yongchang; Xue, Chunyi; Yan, Xu; Liu, Jue

    2016-01-01

    Many viruses exploit the host cell division cycle to favour their own growth. Here we demonstrated that porcine circovirus type 2 (PCV2), which is a major causative agent of an emerging and important swine disease complex, PCV2-associated diseases, caused G0/G1 cell cycle arrest through degradation of cyclin D1 and E followed by reduction of retinoblastoma phosphorylation in synchronized PCV2-infected cells dependent upon virus replication. This induction of G0/G1 cell cycle arrest promoted PCV2 replication as evidenced by increased viral protein expression and progeny virus production in the synchronized PCV2-infected cells. To delineate a mechanism of miRNAs in regulating PCV2-induced G0/G1 cell cycle arrest, we determined expression levels of some relevant miRNAs and found that only miR-15a but not miR-16, miR-21, and miR-34a was significantly changed in the PCV2-infected cells. We further demonstrated that upregulation of miR-15a promoted PCV2-induced G0/G1 cell cycle arrest via mediating cyclins D1 and E degradation, in which involves PCV2 growth. These results reveal that G0/G1 cell cycle arrest induced by PCV2 may provide favourable conditions for viral protein expression and progeny production and that miR-15a is implicated in PCV2-induced cell cycle control, thereby contributing to efficient viral replication. PMID:27302568

  14. Involvement of miR-15a in G0/G1 Phase Cell Cycle Arrest Induced by Porcine Circovirus Type 2 Replication.

    PubMed

    Quan, Rong; Wei, Li; Zhu, Shanshan; Wang, Jing; Cao, Yongchang; Xue, Chunyi; Yan, Xu; Liu, Jue

    2016-01-01

    Many viruses exploit the host cell division cycle to favour their own growth. Here we demonstrated that porcine circovirus type 2 (PCV2), which is a major causative agent of an emerging and important swine disease complex, PCV2-associated diseases, caused G0/G1 cell cycle arrest through degradation of cyclin D1 and E followed by reduction of retinoblastoma phosphorylation in synchronized PCV2-infected cells dependent upon virus replication. This induction of G0/G1 cell cycle arrest promoted PCV2 replication as evidenced by increased viral protein expression and progeny virus production in the synchronized PCV2-infected cells. To delineate a mechanism of miRNAs in regulating PCV2-induced G0/G1 cell cycle arrest, we determined expression levels of some relevant miRNAs and found that only miR-15a but not miR-16, miR-21, and miR-34a was significantly changed in the PCV2-infected cells. We further demonstrated that upregulation of miR-15a promoted PCV2-induced G0/G1 cell cycle arrest via mediating cyclins D1 and E degradation, in which involves PCV2 growth. These results reveal that G0/G1 cell cycle arrest induced by PCV2 may provide favourable conditions for viral protein expression and progeny production and that miR-15a is implicated in PCV2-induced cell cycle control, thereby contributing to efficient viral replication. PMID:27302568

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

    NASA Astrophysics Data System (ADS)

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

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

  16. 5-(2-Carboxyethenyl) isatin derivative induces G{sub 2}/M cell cycle arrest and apoptosis in human leukemia K562 cells

    SciTech Connect

    Zhou, Yao; Zhao, Hong-Ye; Han, Kai-Lin; Yang, Yao; Song, Bin-Bin; Guo, Qian-Nan; Fan, Zhen-Chuan; Zhang, Yong-Min; Teng, Yu-Ou; Yu, Peng

    2014-08-08

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

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

    PubMed

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

    2016-05-01

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

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed

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

    2013-04-01

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

  20. Phosphorylation of eIF2α on Threonine 169 is not required for Trypanosoma brucei cell cycle arrest during differentiation

    PubMed Central

    Avila, Carla Cristi D.C.; Peacock, Lori; Machado, Fabricio Castro; Gibson, Wendy; Schenkman, Sergio; Carrington, Mark; Castilho, Beatriz A.

    2016-01-01

    The trypanosome life cycle consists of a series of developmental forms each adapted to an environment in the relevant insect and/or mammalian host. The differentiation process from the mammalian bloodstream form to the insect-midgut procyclic form in Trypanosoma brucei occurs in two steps in vivo. First proliferating ‘slender' bloodstream forms differentiate to non-dividing ‘stumpy' forms arrested in G1. Second, in response to environmental cues, stumpy bloodstream forms re-enter the cell cycle and start to proliferate as procyclic forms after a lag during which both cell morphology and gene expression are modified. Nearly all arrested cells have lower rates of protein synthesis when compared to the proliferating equivalent. In eukaryotes, one mechanism used to regulate the overall rate of protein synthesis involves phosphorylation of the alpha subunit of initiation factor eIF2 (eIF2α). The effect of eIF2α phosphorylation is to prevent the action of eIF2B, the guanine nucleotide exchange factor that activates eIF2 for the next rounds of initiation. To investigate the role of the phosphorylation of eIF2α in the life cycle of T. brucei, a cell line was made with a single eIF2α gene that contained the phosphorylation site, threonine 169, mutated to alanine. These cells were capable of differentiating from proliferating bloodstream form cells into arrested stumpy forms in mice and into procyclic forms in vitro and in tsetse flies. These results indicate that translation attenuation mediated by the phosphorylation of eIF2α on threonine 169 is not necessary for the cell cycle arrest associated with these differentiation processes. PMID:26996431

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

    PubMed Central

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

    2016-01-01

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

  2. An Ingenol Derived from Euphorbia kansui Induces Hepatocyte Cytotoxicity by Triggering G0/G1 Cell Cycle Arrest and Regulating the Mitochondrial Apoptosis Pathway in Vitro.

    PubMed

    Yan, Xiaojing; Zhang, Li; Cao, Yudan; Yao, Weifeng; Tang, Yuping; Ding, Anwei

    2016-01-01

    Natural product lingenol, a purified diterpenoid compound derived from the root of Euphorbia kansui, exerts serious hepatotoxicity; however, the molecular mechanisms remain to be defined. In the present study, cell counting Kit-8 (CCK-8), inverted phase contrast microscope and flow cytometry were used to demonstrate that lingenol significantly inhibited L-O2 cells proliferation, and induced cell cycle arrest and apoptosis. Moreover, the results investigated that lingenol markedly disrupted mitochondrial functions by high content screening (HCS). In addition, the up-regulation of cytochrome c, AIF and Apaf-1 and activation of caspases were found in L-O2 cells detected by Western blotting and ELISA assay, which was required for lingenol activation of cytochrome c-mediated caspase cascades and AIF-mediated DNA damage. Mechanistic investigations revealed that lingenol significantly down-regulated the Bcl-2/Bax ratio and enhanced the reactive oxygen species (ROS) in L-O2 cells. These data collectively indicated that lingenol modulation of ROS and Bcl-2/Bax ratio led to cell cycle arrest and mitochondrial-mediated apoptosis in L-O2 cells in vitro. All of these results will be helpful to reveal the hepatotoxicity mechanism of Euphorbia kansui and to effectively guide safer and better clinical application of this herb. PMID:27338329

  3. 53BP1 and USP28 mediate p53-dependent cell cycle arrest in response to centrosome loss and prolonged mitosis

    PubMed Central

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

    2016-01-01

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

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

    PubMed

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

    2016-06-01

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

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed

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

    2013-09-01

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

  7. Latcripin-13 domain induces apoptosis and cell cycle arrest at the G1 phase in human lung carcinoma A549 cells.

    PubMed

    Wang, Jia; Wan, Xianyao; Gao, Yifan; Zhong, Mintao; Sha, Li; Liu, Ben; Zhang, Wei; Tian, Li; Ruan, Wenjing; Cao, Shuyun; Huang, Min

    2016-07-01

    Latcripin-13 domain, isolated from the transcriptome of Lentinula edodes C91-3, contains a regulator of chromosome condensation (RCC1) domain/β-lactamase-inhibitor protein II (BLIP-II) and a plant homeodomain (PHD). Latcripin-13 domain has been shown to have antitumor effects. However, the underlying molecular pharmacology is largely unknown. We report here that Latcripin-13 domain induced cell cycle arrest in the G1 phase and caused the apoptosis of human lung carcinoma A549 cells via the GSK3β-cyclin D1 and caspase-8/NF-κB signaling pathways. Western blot analysis showed that Latcripin-13 domain decreased cyclin D1 and cyclin-dependent kinase 4 (CDK4), while it increased the ratio of GSK3β/phosphorylated GSK3β. Importantly, Latcripin-13 domain induced nuclear fragmentation and chromatin condensation in the A549 cells. In addition, treatment of the A549 cells with Latcripin-13 domain resulted in the loss of mitochondrial membrane potential, accompanied by an increase in the Bax/Bcl-2 ratio and activation of caspase-3, -8, and -9. Intriguingly, western blot analysis revealed that NF-κB was significantly downregulated by Latcripin-13 domain. These results demonstrated that Latcripin-13 domain induced apoptosis and cell cycle arrest at G1 phase in the A549 cells, providing a mechanism for the antitumor effects of Latcripin-13 domain. PMID:27221765

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

    PubMed Central

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

    2014-01-01

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

  9. pRB plays an essential role in cell cycle arrest induced by DNA damage

    PubMed Central

    Harrington, Elizabeth A.; Bruce, Jacqueline L.; Harlow, Ed; Dyson, Nicholas

    1998-01-01

    To maintain genome stability, cells with damaged DNA must arrest to allow repair of mutations before replication. Although several key components required to elicit this arrest have been discovered, much of the pathway remains elusive. Here we report that pRB acts as a central mediator of the proliferative block induced by a diverse range of DNA damaging stimuli. Rb−/− mouse embryo fibroblasts are defective in arrest after γ-irradiation, UV irradiation, and treatment with a variety of chemotherapeutic drugs. In contrast, the pRB related proteins p107 and p130 do not play an essential part in the DNA damage response. pRB is required specifically for the G1/S phase checkpoint induced by γ-irradiation. Despite a defect in G1/S phase arrest, levels of p53 and p21 are increased normally in Rb−/− cells in response to γ-irradiation. These results lead us to propose a model in which pRB acts as an essential downstream target of the DNA damage-induced arrest pathway. The ability of pRB to prevent replication of damaged DNA is likely to inhibit the propagation of carcinogenic mutations and may therefore contribute to its role as a tumor suppressor. Furthermore, because many cancer therapies act by damaging DNA, these findings also have implications for the treatment of tumors in which pRB is inactivated. PMID:9751770

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

    PubMed

    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 (P<0.05). Western blot and real-time PCR analysis were used to identify differentially expressed invasion and cell 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

  11. Ajwa Date (Phoenix dactylifera L.) Extract Inhibits Human Breast Adenocarcinoma (MCF7) Cells In Vitro by Inducing Apoptosis and Cell Cycle Arrest

    PubMed Central

    Khan, Fazal; Ahmed, Farid; Pushparaj, Peter Natesan; Abuzenadah, Adel; Kumosani, Taha; Barbour, Elie; AlQahtani, Mohammed; Gauthaman, Kalamegam

    2016-01-01

    Introduction Phoenix dactylifera L (Date palm) is a native plant of the Kingdom of Saudi Arabia (KSA) and other Middle Eastern countries. Ajwa date has been described in the traditional and alternative medicine to provide several health benefits including anticholesteremic, antioxidant, hepatoprotective and anticancer effects, but most remains to be scientifically validated. Herein, we evaluated the anticancer effects of the Methanolic Extract of Ajwa Date (MEAD) on human breast adenocarcinoma (MCF7) cells in vitro. Methods MCF7 cells were treated with various concentrations (5, 10, 15, 20 and 25 mg/ml) of MEAD for 24, 48 and 72 h and changes in cell morphology, cell cycle, apoptosis related protein and gene expression were studied. Results Phase contrast microscopy showed various morphological changes such as cell shrinkage, vacuolation, blebbing and fragmentation. MTT (2-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay demonstrated statistically significant dose-dependent inhibitions of MCF7 cell proliferation from 35% to 95%. Annexin V-FITC and TUNEL assays showed positive staining for apoptosis of MCF7 cells treated with MEAD (15 mg and 25 mg for 48 h). Flow cytometric analyses of MCF7 cells with MEAD (15 mg/ml and 20 mg/ml) for 24 h demonstrated cell cycle arrest at 'S' phase; increased p53, Bax protein expression; caspase 3activation and decreased the mitochondrial membrane potential (MMP). Quantitative real time PCR (qRT-PCR) analysis showed up-regulation of p53, Bax, Fas, and FasL and down-regulation of Bcl-2. Conclusions MEAD inhibited MCF7 cells in vitro by the inducing cell cycle arrest and apoptosis. Our results indicate the anticancer effects of Ajwa dates, which therefore may be used as an adjunct therapy with conventional chemotherapeutics to achieve a synergistic effect against breast cancer. PMID:27441372

  12. Hypoxia enhances glucocorticoid-induced apoptosis and cell cycle arrest via the PI3K/Akt signaling pathway in osteoblastic cells.

    PubMed

    Zou, Wanjing; Yang, Shu; Zhang, Tie; Sun, Haimei; Wang, Yuying; Xue, Hong; Zhou, Deshan

    2015-11-01

    Although osteonecrosis of the femoral head is a known primary limitation of long-term or high-dose clinical administration of glucocorticoids, the mechanisms underlying this side effect remain unclear. Hypoxia is an important biological state under numerous pathological conditions. In this study, we investigated glucocorticoid-induced osteonecrosis under hypoxic conditions in the MC3T3-E1 osteoblast cell line using a cell cytotoxicity assay, flow cytometry, and western blotting. 6α-Methylprednisolone sodium succinate (MPSL) more effectively induced apoptosis and G0/G1 arrest of MC3T3-E1 osteoblasts under hypoxic conditions than under normoxic conditions. Correspondingly, MPSL more effectively upregulated cellular levels of cleaved caspase 3, p53, and its target p21, and downregulated cyclin D1 levels in hypoxia. Moreover, overexpression of Akt abrogated the MPSL activation of p53, p21, and cleaved caspase 3 and the attenuation of cyclin D1 expression and rescued osteoblasts from MPSL-induced cell cycle arrest and apoptosis, indicating that phosphatidylinositol 3-kinase (PI3K)/Akt signaling might play an essential role in MPSL-induced inhibition of osteoblasts. Furthermore, the suppression of PI3K/Akt signaling and upregualtion of cellular p85α monomer levels by MPSL were more pronounced under hypoxic conditions than under normoxic conditions. Finally, we found that the enhancement of the effects of MPSL under hypoxic conditions was attributed to hypoxia-upregulated glucocorticoid receptor activity. In conclusion, our results demonstrate that MPSL, a synthetic glucocorticoid receptor agonist, promotes the level of p85α and inhibits PI3K/Akt signaling to induce apoptosis and cell cycle arrest in osteoblasts, and that this effect is enhanced under hypoxic conditions. PMID:25230819

  13. Etoposide-induced cell cycle delay and arrest-dependent modulation of DNA topoisomerase II in small-cell lung cancer cells.

    PubMed Central

    Smith, P. J.; Souès, S.; Gottlieb, T.; Falk, S. J.; Watson, J. V.; Osborne, R. J.; Bleehen, N. M.

    1994-01-01

    As an approach to the rational design of combination chemotherapy involving the anti-cancer DNA topoisomerase II poison etoposide (VP-16), we have studied the dynamic changes occurring in small-cell lung cancer (SCLC) cell populations during protracted VP-16 exposure. Cytometric methods were used to analyse changes in target enzyme availability and cell cycle progression in a SCLC cell line, mutant for the tumour-suppressor gene p53 and defective in the ability to arrest at the G1/S phase boundary. At concentrations up to 0.25 microM VP-16, cells became arrested in G2 by 24 h exposure, whereas at concentrations 0.25-2 microM G2 arrest was preceded by a dose-dependent early S-phase delay, confirmed by bromodeoxyuridine incorporation. Recovery potential was determined by stathmokinetic analysis and was studied further in aphidicolin-synchronised cultures released from G1/S and subsequently exposed to VP-16 in early S-phase. Cells not experiencing a VP-16-induced S-phase delay entered G2 delay dependent upon the continued presence of VP-16. These cells could progress to mitosis during a 6-24 h period after drug removal. Cells experiencing an early S-phase delay remained in long-term G2 arrest with greatly reducing ability to enter mitosis up to 24 h after removal of VP-16. Irreversible G2 arrest was delimited by the induction of significant levels of DNA cleavage or fragmentation, not associated with overt apoptosis, in the majority of cells. Western blotting of whole-cell preparations showed increases in topoisomerase II levels (up to 4-fold) attributable to cell cycle redistribution, while nuclei from cells recovering from S-phase delay showed enhanced immunoreactivity with an anti-topoisomerase II alpha antibody. The results imply that traverse of G1/S and early S-phase in the presence of a specific topoisomerase II poison gives rise to progressive low-level trapping of topoisomerase II alpha, enhanced topoisomerase II alpha availability and the subsequent

  14. Suppression of urinary bladder urothelial carcinoma cell by the ethanol extract of pomegranate fruit through cell cycle arrest and apoptosis

    PubMed Central

    2013-01-01

    Background Pomegranate possesses many medicinal properties such as antioxidant, anti-inflammation and antitumor. It has been extensively used as a folk medicine by many cultures. Pomegranate fruit has been shown to have the inhibitory efficacy against prostate cancer and lung cancer in vitro and in vivo. It can be exploited in chemoprevention and chemotherapy of prostate cancer. In this study we examined the anti-cancer efficacy of pomegranate fruit grown in Taiwan against urinary bladder urothelial carcinoma (UBUC) and its mechanism of action. Methods Edible portion of Taiwanese pomegranate was extracted using ethanol and the anti-cancer effectiveness of ethanol extract was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Flow cytometry and western immunoblotting were exploited to uncover the molecular pathways underlying anti-UBUC activity of Taiwanese pomegranate ethanol extract. Results This study demonstrated that Taiwanese pomegranate fruit ethanol extract (PEE) could effectively restrict the proliferation of UBUC T24 and J82 cells. Cell cycle analyses indicated that the S phase arrest induced by PEE treatment might be caused by an increase in cyclin A protein level and a decrease in the expression of cyclin-dependent kinase 1. The results of western immunoblotting demonstrated that PEE treatment could not only evoke the activation of pro-caspase-3, -8,-9 but also increase Bax/Bcl-2 ratio in T24 cells. The above observations implicated that PEE administration might trigger the apoptosis in T24 cells through death receptor signaling and mitochondrial damage pathway. Besides we found that PEE exposure to T24 cells could provoke intensive activation of procaspase-12 and enhance the expressions of CHOP and Bip, endoplasmic reticulum (ER) stress marker, suggesting that ER stress might be the cardinal apoptotic mechanism of PEE-induced inhibition of bladder cancer cell. Conclusions The analytical results of this study help to provide

  15. A Potent HDAC Inhibitor, 1-Alaninechlamydocin, from a Tolypocladium sp. Induces G2/M Cell Cycle Arrest and Apoptosis in MIA PaCa-2 Cells

    PubMed Central

    2015-01-01

    The cyclic tetrapeptide 1-alaninechlamydocin was purified from a Great Lakes-derived fungal isolate identified as a Tolypocladium sp. Although the planar structure was previously described, a detailed analysis of its spectroscopic data and biological activity are reported here for the first time. Its absolute configuration was determined using a combination of spectroscopic (1H–1H ROESY, ECD, and X-ray diffraction) and chemical (Marfey’s analysis) methods. 1-Alaninechlamydocin showed potent antiproliferative/cytotoxic activities in a human pancreatic cancer cell line (MIA PaCa-2) at low-nanomolar concentrations (GI50 5.3 nM, TGI 8.8 nM, LC50 22 nM). Further analysis revealed that 1-alaninechlamydocin induced G2/M cell cycle arrest and apoptosis. Similar to other cyclic epoxytetrapeptides, the inhibitory effects of 1-alaninechlamydocin are proposed to be produced primarily via inhibition of histone deacetylase (HDAC) activity. PMID:24999749

  16. Studies with GFP-Vpr fusion proteins: induction of apoptosis but ablation of cell-cycle arrest despite nuclear membrane or nuclear localization.

    PubMed

    Waldhuber, Megan G; Bateson, Michael; Tan, Judith; Greenway, Alison L; McPhee, Dale A

    2003-08-15

    The human immunodeficiency virus type 1 (HIV-1) Vpr protein is known to arrest the cell cycle in G(2)/M and induce apoptosis following arrest. The functions of Vpr relative to its location in the cell remain unresolved. We now demonstrate that the location and function of Vpr are dependent on the makeup of fusion proteins and that the functions of G(2)/M arrest and apoptosis are separable. Using green fluorescence protein mutants (EGFP or EYFP), we found that fusion at either the N- or C-terminus compromised the ability of Vpr to arrest cell cycling, relative to that of His-Vpr or wild-type protein. Additionally, utilizing the ability to specifically identify cells expressing the fusion proteins, we confirm that Vpr can induce apoptosis, but appears to be independent of cell-cycle arrest in G(2)/M. Both N- and C-terminal Vpr/EYFP fusion proteins induced apoptosis but caused minimal G(2)/M arrest. These studies with Vpr fusion proteins indicate that the functions of Vpr leading to G(2)/M arrest and apoptosis are separable and that fusion of Vpr to EGFP or EYFP affected the localization of the protein. Our findings suggest that nuclear membrane localization and nuclear import and export are strongly governed by modification of the N-terminus of Vpr. PMID:12951024

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

    PubMed

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

    2013-06-01

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

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed

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

    2016-01-01

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

  20. No defect in G1/S cell cycle arrest in irradiated Li-Fraumeni lymphoblastoid cell lines.

    PubMed Central

    Williams, K. J.; Heighway, J.; Birch, J. M.; Norton, J. D.; Scott, D.

    1996-01-01

    The radiation response of Epstein-Barr virus (EBV)-immortalised lymphoblastoid cell lines derive from Li-Fraumeni syndrome (LFS) and LFS-like individuals was investigated. Cells from all LFS and LFS-like cases showed an accumulation of p53 protein following 137Cs gamma-irradiation, which was associated with cell cycle arrest at the G1/S border. This response was indistinguishable from that seen in cells derived from normal individuals, and occurred in cases with missense mutations in the TP53 gene at codons 175, 180, 220 and 248 and also in two LFS-like individuals with no TP53 mutation. Previous studies using lymphocytes and fibroblasts from LFS individuals have demonstrated abnormal radiation responses in these cells. This suggest cell type specificity in the contribution of a mutant p53 protein to phenotype. Images Figure 1 Figure 4 PMID:8795570

  1. Trichosanthes kirilowii fruits inhibit non-small cell lung cancer cell growth through mitotic cell-cycle arrest.

    PubMed

    Ni, Lulu; Zhu, Xiaowen; Gong, Chenyuan; Luo, Yinbin; Wang, Lixin; Zhou, Wuxiong; Zhu, Shiguo; Li, Yan

    2015-01-01

    Lung cancer is the leading cause of cancer-related death worldwide. Non-small cell lung cancer (NSCLC) accounts for 80% of lung cancer cases and the reported overall 5-year survival rate is less than 5%. Natural medicines have attracted much attention due to their lower toxicity and fewer side effects. Trichosanthes kirilowii Maxim (TKM) fruits are commonly used in cancer treatment in combination with other Chinese medicinal herbs. However, little is known about their biological functions and mechanisms in NSCLC cells. In this study, we investigated the efficacy of TKM fruits in NSCLC cells using cell proliferation, invasion, migration, and anchorage independent assays and a Xenograft NSCLC tumor model, and explored the possible biological mechanism by flow cytometric analysis, cDNA microarray and real-time PCR. Results showed that TKM fruits significantly suppressed NSCLC cell proliferation, migration, invasion, tumorigenicity and tumor growth, and significantly extended the survival time of NSCLC-bearing mice. Flow cytometric analysis showed that TKM fruits significantly induced G2-M arrest, necrosis and apoptosis in NSCLC cells. cDNA microarray analysis revealed that TKM fruits regulated the differential expression of 544 genes, and the differential expression of selected genes was also confirmed. Gene ontology (GO) analysis showed that 18 of first 20 biological processes were involved in cell cycle and mitosis. These results indicate that TKM fruits have certain inhibitory effect on NSCLC cells through cell-cycle and mitosis arrest, and suggest that TKM fruits may be an important resource for developing new antitumor drugs, and a potent natural product for treating patients with NSCLC. PMID:25779643

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

    PubMed

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

    2015-03-01

    TiO2 nanoparticles (NPs) have the second highest global annual production (∼3000 tons) among the metal-containing NPs. These NPs are used as photocatalysts for bacterial disinfection, and in various other consumer products including sunscreen, food packaging, therapeutics, biosensors, surface cleaning agents, and others. Humans are exposed to these NPs during synthesis (laboratory), manufacture (industry), and use (consumer products, devices, medicines, etc.), as well as through environmental exposures (disposal). Hence, there is great concern regarding the health effects caused by exposure to NPs and, in particular, to TiO2 NPs. In the present study, the genotoxic potential of TiO2 NPs in A549 cells was examined, focusing on their potential to induce ROS, different types of DNA damage, and cell cycle arrest. We show that TiO2 NPs can induce DNA damage and a corresponding increase in micronucleus frequency, as evident from the comet and cytokinesis-block micronucleus assays. We demonstrate that DNA damage may be attributed to increased oxidative stress and ROS generation. Furthermore, genomic and proteomic analyses showed increased expression of ATM, P53, and CdC-2 and decreased expression of ATR, H2AX, and Cyclin B1 in A549 cells, suggesting induction of DNA double strand breaks. The occurrence of double strand breaks was correlated with cell cycle arrest in G2/M phase. Overall, the results indicate the potential for genotoxicity following exposure to these TiO2 NPs, suggesting that use should be carefully monitored. PMID:25524809

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

    PubMed Central

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

    2014-01-01

    The purpose of this study was to evaluate the effects of corn naturally contaminated with aflatoxin B1 and aflatoxin B2 on pathological lesions, apoptosis, cell cycle phases and T lymphocyte subsets of spleen, and to provide an experimental basis for understanding the mechanism of aflatoxin-induced immunosuppression. A total of 900 COBB500 male broilers were randomly allocated into five groups with six replicates per group and 30 birds per replicate. The experiment lasted for 6 weeks and the five dietary treatments consisted of control, 25% contaminated corn, 50% contaminated corn, 75% contaminated corn and 100% contaminated corn groups. The histopathological spleen lesions from the contaminated corn groups was characterized as congestion of red pulp, increased necrotic cells and vacuoles in the splenic corpuscle and periarterial lymphatic sheath. The contaminated corn intake significantly increased relative weight of spleen, percentages of apoptotic splenocytes, induced cell cycle arrest of splenocytes, increased the percentages of CD3+CD8+ T cells and decreased the ratios of CD3+CD4+ to CD3+CD8+. The results suggest that AFB-induced immunosuppression maybe closely related to the lesions of spleen. PMID:25141002

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

    PubMed

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

    2015-06-01

    The pharmacological potential of curcumin (CURC) is severely restricted because of its low water solubility/absorption, short half-life and poor bioavailability. To overcome these issues, CURC-loaded nanoparticles (NPs) were produced by a double emulsion technique. In particular, NPs were made up of an amphiphilic blend of poloxamers and PLGA to confer stealth properties to the NPs to take advantage of the enhanced permeability and retention (EPR) effect. Different surface properties of NPs made up of bare PLGA and PLGA/poloxamer blend were confirmed by the different interactions of these NPs with serum proteins and also by their ability to be internalized by mesothelioma cell line. The uptake of PLGA/poloxamer NPs induces a persistent block in G0/G1 phase of the cell cycle up to 72 h, thus overcoming the drug tolerance phenomenon, normally evidenced with free CURC. PMID:25794477

  5. High levels of endogenous nitric oxide produced after burn injury in rats arrest activated T lymphocytes in the first G1 phase of the cell cycle and then induce their apoptosis

    SciTech Connect

    Valenti, Lionel M.; Chancerelle, Yves; Sousa, Martine de; Anh Tuan Dinh-Xuan

    2005-05-15

    Major physical traumas provoke a systemic inflammatory response and immune dysfunction. In a model of thermal injury in rats, we previously showed that an overproduction of nitric oxide (NO) was responsible for the collapse of lymphoproliferative responses. In the present work, we performed a time-course analysis of cell proliferation and cell death parameters in order to establish the sequence of events triggered by the high NO output in Wistar/Han rat splenocytes activated with Con A, 10 days after burn injury. We demonstrate that activated T cells from burned rats never divided whereas normal T cells underwent four division cycles. However, T cells from both burned and normal rat entered the G1 phase as shown by increase of cell size, mitochondria hyperpolarization, and expression of cyclin D1. Burned rat T cells progressed to the late G1 phase as shown by expression of the nuclear Ki-67 antigen, but they never entered the S phase. They underwent apoptosis as shown by morphological parameters, disruption of transmembrane mitochondrial potential, and DNA fragmentation. Persistent accumulation of the p53 protein accompanied these phenomena. NO synthase inhibitors antagonize alterations of cell proliferation and cell death parameters in burned rat T cells and accelerated p53 turnover.

  6. Myc inhibits p27-induced erythroid differentiation of leukemia cells by repressing erythroid master genes without reversing p27-mediated cell cycle arrest.

    PubMed

    Acosta, Juan C; Ferrándiz, Nuria; Bretones, Gabriel; Torrano, Verónica; Blanco, Rosa; Richard, Carlos; O'Connell, Brenda; Sedivy, John; Delgado, M Dolores; León, Javier

    2008-12-01

    Inhibition of differentiation has been proposed as an important mechanism for Myc-induced tumorigenesis, but the mechanisms involved are unclear. We have established a genetically defined differentiation model in human leukemia K562 cells by conditional expression of the cyclin-dependent kinase (Cdk) inhibitor p27 (inducible by Zn(2+)) and Myc (activatable by 4-hydroxy-tamoxifen). Induction of p27 resulted in erythroid differentiation, accompanied by Cdk inhibition and G(1) arrest. Interestingly, activation of Myc inhibited p27-mediated erythroid differentiation without affecting p27-mediated proliferation arrest. Microarray-based gene expression indicated that, in the presence of p27, Myc blocked the upregulation of several erythroid-cell-specific genes, including NFE2, JUNB, and GATA1 (transcription factors with a pivotal role in erythropoiesis). Moreover, Myc also blocked the upregulation of Mad1, a transcriptional antagonist of Myc that is able to induce erythroid differentiation. Cotransfection experiments demonstrated that Myc-mediated inhibition of differentiation is partly dependent on the repression of Mad1 and GATA1. In conclusion, this model demonstrates that Myc-mediated inhibition of differentiation depends on the regulation of a specific gene program, whereas it is independent of p27-mediated cell cycle arrest. Our results support the hypothesis that differentiation inhibition is an important Myc tumorigenic mechanism that is independent of cell proliferation. PMID:18838534

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

    PubMed

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

    2015-05-01

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

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

    PubMed Central

    2014-01-01

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

  9. Effects of maple (Acer) plant part extracts on proliferation, apoptosis and cell cycle arrest of human tumorigenic and non-tumorigenic colon cells.

    PubMed

    González-Sarrías, Antonio; Li, Liya; Seeram, Navindra P

    2012-07-01

    Phenolic-enriched extracts of maple sap and syrup, obtained from the sugar and red maple species (Acer saccharum Marsh, A. rubrum L., respectively), are reported to show anticancer effects. Despite traditional medicinal uses of various other parts of these plants by Native Americans, they have not been investigated for anticancer activity. Here leaves, stems/twigs, barks and sapwoods of both maple species were evaluated for antiproliferative effects against human colon tumorigenic (HCT-116, HT-29, Caco-2) and non-tumorigenic (CCD-18Co) cells. Extracts were standardized to total phenolic and ginnalin-A (isolated in our laboratory) levels. Overall, the extracts inhibited the growth of the colon cancer more than normal cells (over two-fold), their activities increased with their ginnalin-A levels, with red > sugar maple extracts. The red maple leaf extract, which contained the highest ginnalin-A content, was the most active extract (IC₅₀  = 35 and 16 µg/mL for extract and ginnalin-A, respectively). The extracts were not cytotoxic nor did they induce apoptosis of the colon cancer cells. However, cell cycle analyses revealed that the antiproliferative effects of the extracts were mediated through cell cycle arrest in the S-phase. The results from the current study suggest that these maple plant part extracts may have potential anticolon cancer effects. PMID:22147441

  10. Shikonin causes cell-cycle arrest and induces apoptosis by regulating the EGFR–NF-κB signalling pathway in human epidermoid carcinoma A431 cells

    PubMed Central

    Tian, Rong; Li, You; Gao, Mei

    2015-01-01

    Shikonin, a naphthoquinone pigment isolated from the Chinese herbal Zicao, has been shown to exhibit antioxidant and anticancer effects. In the present study, we investigated the antiproliferative and pro-apoptotic effects of shikonin on A431 cells and explored the underlying molecular mechanisms. In the present study, our results showed that shikonin significantly inhibited the growth of A431 cells in a concentration- and time-dependent manner, and caused cell cycle arrest by upregulation of p21 and p27, and downregulation of cyclins and cyclin-dependent kinases. In addition, shikonin evidently induced apoptosis due to decreasing Bcl-2 expression, increasing Bax expression, activating caspase and inactivating NF-κB, while pretreatment with a pan-caspase inhibitor Z-Asp-CH2-DCB abrogated shikonin-induced apoptosis. Moreover, EGF could significantly increase the NF-κB DNA-binding activity and reversed the shikonin-induced inactivation of NF-κB. As anticipated AG1478 (EGFR inhibitor) and Bay11-7082 (NF-κB inhibitor) blocked EGF-reversed the inactivation of NF-κB induced by shikonin. Our data also showed that EGF could evidently reverse the shikonin-induced decreases in cell viability and increases in apoptosis. Then, the NF-κB inhibitors such as Bay11-7082, SN50, Helenalin and the EGFR inhibitor AG1478 and its downstream inhibitor such as PI3K inhibitor LY294002 and STAT3 inhibitor Stattic dramatically blocked EGF-reversed decreases in cell viability and increases in apoptosis induced by shikonin. Collectively, our findings indicated that shikonin inhibited cell growth and caused cell cycle arrest of the A431 cells through the regulation of apoptosis. Moreover, these effects were mediated at least partially by suppressing the activation of the EGFR–NF-κB signaling pathways. PMID:25720435

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

    PubMed

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

    2015-08-01

    mTOR is aberrantly activated in hepatocellular carcinoma (HCC) and plays pivotal roles in tumorigenesis and chemoresistance. Rapamycin has been reported to exert antitumor activity in HCC and sensitizes HCC cells to cytotoxic agents. However, due to feedback activation of AKT after mTOR complex 1 (mTORC1) inhibition, simultaneous targeting of mTORC1/2 may be more effective. In this study, we examined the interaction between the dual mTORC1/2 inhibitor OSI-027 and doxorubicin in vitro and in vivo. OSI-027 was found to reduce phosphorylation of both mTORC1 and mTORC2 substrates, including 4E-BP1, p70S6K, and AKT (Ser473), and inhibit HCC cell proliferation. Similar to OSI-027 treatment, knockdown of mTORC2 induced G0-G1 phase cell-cycle arrest. In contrast, rapamycin or knockdown of mTORC1 increased phosphorylation of AKT (Ser473), yet had little antiproliferative effect. Notably, OSI-027 synergized with doxorubicin for the antiproliferative efficacy in a manner dependent of MDR1 expression in HCC cells. The synergistic antitumor effect of OSI-027 and doxorubicin was also observed in a HCC xenograft mouse model. Moreover, AKT was required for OSI-027-induced cell-cycle arrest and downregulation of MDR1. Our findings provide a rationale for dual mTORC1/mTORC2 inhibitors, such as OSI-027, as monotherapy or in combination with cytotoxic agents to treat HCC. Mol Cancer Ther; 14(8); 1805-15. ©2015 AACR. PMID:26026051

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

    PubMed

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

    2016-08-19

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

  13. 2,5-dimethyl-4-hydroxy-3(2H)-furanone (DMHF); antimicrobial compound with cell cycle arrest in nosocomial pathogens.

    PubMed

    Sung, Woo Sang; Jung, Hyun Jun; Park, Keunnam; Kim, Hyun Soo; Lee, In-Seon; Lee, Dong Gun

    2007-01-16

    2,5-Dimethyl-4-hydroxy-3(2H)-furanone (DMHF), an aroma compound found in a number of fruits and foods, has shown various biological properties in animal models, but its antimicrobial effect remains poorly understood. The current study investigated the antimicrobial effect of DMHF using human pathogenic microorganisms including clinically isolated antibiotics-resistant strains. The results indicated that DMHF exhibited broad spectrum antimicrobial activities in an energy-dependent manner without hemolytic effect on human erythrocytes. To confirm antifungal effect of DMHF, we investigated the effect on dimorphism of Candida albicans induced by FBS, which plays a key role for pathogenesis in host invasion. The result showed that DMHF exerted a potent antifungal activity on the serum-induced mycelia of C. albicans. To elucidate the physiological changes of the fungal cells induced by DMHF, cell cycle analysis was performed, and the results showed that DMHF arrested the cell cycle at the S and G2/M phase in yeast. Therefore, it could be expected that DMHF may have potential as an anti-infective agent in human microbial infections. PMID:17097685

  14. The Ethanolic Extract of Taiwanofungus camphoratus (Antrodia camphorata) Induces Cell Cycle Arrest and Enhances Cytotoxicity of Cisplatin and Doxorubicin on Human Hepatocellular Carcinoma Cells

    PubMed Central

    Lin, Liang-Tzung; Tai, Chen-Jei; Su, Ching-Hua; Chang, Fang-Mo; Choong, Chen-Yen; Wang, Chien-Kai; Tai, Cheng-Jeng

    2015-01-01

    Taiwanofungus camphoratus (synonym Antrodia camphorata) is a widely used medicinal fungus in the folk medicine of Taiwan with several pharmacological features such as anti-inflammatory, liver protection, antihypertensive, and antioxidative activities. The ethanolic extract of T. camphoratus (TCEE) which contains abundant bioactive compounds including triterpenoids and polysaccharides also has antitumor effects in various human cancer cell lines. The aims of this study are to clarify the antitumor effects of TCEE on human hepatocellular carcinoma cells and also evaluate the combination drug effects with conventional chemotherapy agents, cisplatin and doxorubicin. In the present study, the TCEE treatment induced cell cycle arrest and suppressed cell growth on both Hep3B and HepJ5 cells. Expression of cell cycle inhibitors, P21 and P27, and activation of apoptosis executer enzyme, caspase-3, were also induced by TCEE. In combination with the chemotherapy agents, TCEE treatment further enhanced the tumor suppression efficiency of cisplatin and doxorubicin. These results together suggested that TCEE is a potential ingredient for developing an integrated chemotherapy for human liver cancer. PMID:26557666

  15. The Resveratrol Tetramer r-Viniferin Induces a Cell Cycle Arrest Followed by Apoptosis in the Prostate Cancer Cell Line LNCaP.

    PubMed

    Empl, Michael T; Albers, Malena; Wang, Shan; Steinberg, Pablo

    2015-10-01

    Polyphenols are secondary plant metabolites that possess potentially health-promoting properties and which occur in various edible plants and plant products. Especially the stilbenoid resveratrol has been extensively studied regarding its anticarcinogenic and chemopreventive activities. However, research has recently focused on the investigation of other natural or synthetic compounds in order to find substances that show a higher bioactivity and/or bioavailability than resveratrol. In this context, we exemplarily investigated the cytotoxic/growth-inhibiting properties of the resveratrol tetramer r-viniferin on the prostate cancer cell line LNCaP and compared them with those of resveratrol. By using the sulforhodamine B assay followed by cell cycle analysis via flow cytometry and commercially available apoptosis/necrosis assay kits, we show that both compounds were able to inhibit the growth of LNCaP cells and to induce a cell cycle arrest in the G1 phase. However, r-viniferin was significantly more potent in inhibiting cellular growth than resveratrol and the only compound that increased the apoptotic cellular fraction as well as the activity of apoptosis-associated enzymes. In conclusion, r-viniferin leads to cytotoxicity in LNCaP cells at fairly low concentrations, and it is therefore conceivable that it might be used as a chemopreventive agent or as an adjuvant in prostate cancer therapy. PMID:26331691

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

    PubMed Central

    Navanesan, Suerialoasan; Abdul Wahab, Norhanom; Manickam, Sugumaran; Sim, Kae Shin

    2015-01-01

    Leptospermum flavescens Sm. (Myrtaceae), locally known as ‘Senna makki’ is a smallish tree that is widespread and recorded to naturally occur in the montane regions above 900 m a.s.l from Burma to Australia. Although the species is recorded to be used traditionally to treat various ailments, there is limited data on biological and chemical investigations of L. flavescens. The aim of the present study was to investigate and understand the ability of L. flavescens in inducing cell death in lung cancer cells. The cytotoxic potentials of the extraction yields (methanol, hexane, ethyl acetate and water extracts as wells as a semi pure fraction, LF1) were evaluated against two human non-small cell lung carcinoma cell lines (A549 and NCI-H1299) using the MTT assay. LF1 showed the greatest cytotoxic effect against both cell lines with IC50 values of 7.12 ± 0.07 and 9.62 ± 0.50 μg/ml respectively. LF1 treated cells showed a sub-G1 region in the cell cycle analysis and also caused the presence of apoptotic morphologies in cells stained with acridine orange and ethidium bromide. Treatment with LF1 manifested an apoptotic population in cells that were evaluated using the Annexin V/ propidium iodide assay. Increasing dosage of LF1 caused a rise in the presence of activated caspase-3 enzymes in treated cells. Blockage of cell cycle progression was also observed in LF1-treated cells. These findings suggest that LF1 induces apoptosis and cell cycle arrest in treated lung cancer cells. Further studies are being conducted to isolate and identify the active compound as well to better understand the mechanism involved in inducing cell death. PMID:26287817

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

    PubMed

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

    2015-01-01

    The present study was conducted to investigate the effect of γ-radiation alone or combined with a cytotoxic drug, simvastatin, on viability and cell cycling of a myeloma cell line. P3NS1 myeloma cells were treated with the selected dose of simvastatin (0.1 μM/l) 24 hours prior to γ-irradiation (0.25, 0.5 and 1 Gy). The cell viability, induction of apoptosis, cell death, cell cycling, generation of ROS, and expression of P53, Bax, Bcl2, caspase3, PARP1 and Fas genes were estimated. The results indicated that simvastatin (0.1 μM/l) treatment for 24 hours prior to γ- irradiation increased cell death to 37.5% as compared to 4.81% by radiation (0.5 Gy) alone. It was found that simvastatin treatment before irradiation caused arrest of cells in G0/G1 and G2/M phases as assessed using flow cytometry. Interestingly, simvastatin treatment of P3NS1 cells increased the intracellular ROS production and decreased antioxidant enzyme activity with increased P53, Bax and Caspase3 gene expression while that of Bcl2 was decreased. Consequently, our results indicated that pre-treatment with simvastatin increased radio sensitivity of myeloma tumor cells in addition to apoptotic effects through an intrinsic mitochondrial pathway. PMID:26514497

  18. 1-(2-Hydroxy-5-methylphenyl)-3-phenyl-1,3-propanedione Induces G1 Cell Cycle Arrest and Autophagy in HeLa Cervical Cancer Cells

    PubMed Central

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

    2016-01-01

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

  19. Rapid onset of nucleolar disintegration preceding cell cycle arrest in roscovitine-induced apoptosis of human MCF-7 breast cancer cells.

    PubMed

    Wojciechowski, Jacek; Horky, Marcel; Gueorguieva, Marieta; Wesierska-Gadek, Józefa

    2003-09-10

    The aim of our study was to explore the antiproliferative and pro-apoptotic action of roscovitine (ROSC) on human breast cancer MCF-7 cells. We examined the effect of ROSC on cell proliferation, cell cycle progression, nucleolar morphology, posttranslational modifications of histones as well as on induction of apoptosis. The effects of ROSC on the argyrophilic nucleolar organizer regions (AgNORs) and nucleolar RNA of MCF-7 cells were marked: ROSC treatment changed the pattern of AgNORs in a time-dependent manner. The disintegration of nucleoli manifested by increasing number of nucleolar fragments already began at 6 hr posttreatment. This was accompanied by a redistribution of the nucleolin from the nucleolus beginning after 6 hr and preceded a decrease of histone acetylation and phosphorylation. Inhibition of DNA synthesis and accumulation of G(2)/M-arrested cells starting 6 hr posttreatment coincided with a strong increase of the p53 level and with an appearance of a few cells committed to undergo apoptosis. However, all these changes preceded the main wave of apoptosis, which occurred after 24 hr ROSC treatment as assessed by determination of the frequency of Annexin binding, activation of caspases as well as of DNA fragmentation. Onset of PARP-1 cleavage detected by immunoblotting and by immunohistochemistry 6 hr or 9 hr posttreatment, respectively, preceded for a few hours the DNA fragmentation detected in situ by TUNEL assay. Reconstitution of MCF-7 cells with caspase-3 did not change the kinetics of ROSC-induced apoptosis. Our results show that disintegration of nucleoli is an early marker of ROSC-induced changes. Cell cycle arrest precedes the main wave of apoptosis. PMID:12845642

  20. Paris Saponins enhance radiosensitivity in a gefitinib‑resistant lung adenocarcinoma cell line by inducing apoptosis and G2/M cell cycle phase arrest.

    PubMed

    Zhao, Peng-Jun; Song, Shui-Chuan; Du, Lei-Wen; Zhou, Guo-Hua; Ma, Sheng-Lin; Li, Jin-Hui; Feng, Jian-Guo; Zhu, Xin-Hai; Jiang, Hao

    2016-03-01

    Acquired resistance to epidermal growth factor inhibitors has been reported to be associated with cross‑resistance to radiation. Paris Saponins (PSs) exert a wide range of pharmacological activities, including cell apoptosis induction, multidrug resistance inhibition, angiogenesis inhibition and tumor cell migration by modulating various signaling pathways. The present study aimed to investigate the radiosensitization effects of PSII, PSVI and PSVII in a gefitinib‑resistant PC‑9‑ZD lung adenocarcinoma cell line, and the possible mechanism underlying their function. A clonogenic assay was performed to determine the effects of PS radiosensitization on the PC‑9‑ZD cell line. The cell cycle was analyzed by flow cytometry, and cell apoptosis was analyzed with Annexin V/propidium iodide and Hoechst staining. Protein expression levels were detected by western blotting. The results of the present study revealed a significant increase in PC‑9‑ZD cell line radiosensitivity following treatment with PSs. PSs induced G2/M cell cycle phase arrest and apoptosis of the irradiated PC‑9‑ZD cells. Notably, the expression levels of B cell lymphoma 2 (Bcl‑2) were downregulated, and those of caspase‑3, Bcl‑2‑associated X protein (Bax) and p21/Waf1/Cip1 were upregulated following treatment with PSs. The present results demonstrated that PSs induced radiosensitivity in gefitinib‑resistant cells by inducing G2/M phase arrest and by enhancing the apoptotic response via the modulation of caspase‑3, Bax, Bcl‑2 and p21/Waf1/Cip1 expression. PMID:26846193

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

    PubMed

    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. TSG101 Silencing Suppresses Hepatocellular Carcinoma Cell Growth by Inducing Cell Cycle Arrest and Autophagic Cell Death

    PubMed Central

    Shao, Zhuo; Ji, Weiping; Liu, Anan; Qin, Ancheng; Shen, Li; Li, Gang; Zhou, Yinqi; Hu, Xiangui; Yu, Enda; Jin, Gang

    2015-01-01

    Background The tumor susceptibility gene 101 (TSG101) was originally identified as a tumor-suppressor gene that mediates many molecular and biological processes, such as ubiquitination, endosomal trafficking, cell survival, and virus budding, but its role in hepatocellular carcinoma (HCC) is currently unknown. Material/Methods We assessed the expression of TSG101 in HCC and paracancerous tissues using qPCR. Then, we used the TSG101-specific siRNA mix to disrupt the expression of TSG101 to investigate the subsequent effect on human hepatoma-7 (Huh7) cells. Western blot was used to detect the protein expression of TSG101 and other molecules. Cell growth assay was performed using CCK8. Transwell assay was used to investigate the migration and invasion ability of Huh7 cells after transfection with of TSG101 siRNA. Flow cytometry was used to estimate the effect of TSG101 knockdown on cell cycle and apoptosis. Confocal laser scanning microscopy was used to observe the actin filaments change and the formation of autophagy. Results TSG101 was over-expressed in HCC tissues. TSG101 silence was able to suppress Huh7 cell proliferation, migration, and invasion. Furthermore, silencing of TSG101 could induce cell cycle arrest at G1 phase and inhibit the expression of cyclin A and cyclin D, while up-regulating the expression of CDK2. The mechanism might be induction of autophagic cell death and inactivation of Akt and ERK1/2. Conclusions TSG101 plays an important role in the development of HCC and may be a target for molecular therapy. PMID:26537625

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

    SciTech Connect

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

    2006-07-28

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

  4. RCC1-dependent activation of Ran accelerates cell cycle and DNA repair, inhibiting DNA damage-induced cell senescence.

    PubMed

    Cekan, Pavol; Hasegawa, Keisuke; Pan, Yu; Tubman, Emily; Odde, David; Chen, Jin-Qiu; Herrmann, Michelle A; Kumar, Sheetal; Kalab, Petr

    2016-04-15

    The coordination of cell cycle progression with the repair of DNA damage supports the genomic integrity of dividing cells. The function of many factors involved in DNA damage response (DDR) and the cell cycle depends on their Ran GTPase-regulated nuclear-cytoplasmic transport (NCT). The loading of Ran with GTP, which is mediated by RCC1, the guanine nucleotide exchange factor for Ran, is critical for NCT activity. However, the role of RCC1 or Ran⋅GTP in promoting cell proliferation or DDR is not clear. We show that RCC1 overexpression in normal cells increased cellular Ran⋅GTP levels and accelerated the cell cycle and DNA damage repair. As a result, normal cells overexpressing RCC1 evaded DNA damage-induced cell cycle arrest and senescence, mimicking colorectal carcinoma cells with high endogenous RCC1 levels. The RCC1-induced inhibition of senescence required Ran and exportin 1 and involved the activation of importin β-dependent nuclear import of 53BP1, a large NCT cargo. Our results indicate that changes in the activity of the Ran⋅GTP-regulated NCT modulate the rate of the cell cycle and the efficiency of DNA repair. Through the essential role of RCC1 in regulation of cellular Ran⋅GTP levels and NCT, RCC1 expression enables the proliferation of cells that sustain DNA damage. PMID:26864624

  5. RCC1-dependent activation of Ran accelerates cell cycle and DNA repair, inhibiting DNA damage–induced cell senescence

    PubMed Central

    Cekan, Pavol; Hasegawa, Keisuke; Pan, Yu; Tubman, Emily; Odde, David; Chen, Jin-Qiu; Herrmann, Michelle A.; Kumar, Sheetal; Kalab, Petr

    2016-01-01

    The coordination of cell cycle progression with the repair of DNA damage supports the genomic integrity of dividing cells. The function of many factors involved in DNA damage response (DDR) and the cell cycle depends on their Ran GTPase–regulated nuclear–cytoplasmic transport (NCT). The loading of Ran with GTP, which is mediated by RCC1, the guanine nucleotide exchange factor for Ran, is critical for NCT activity. However, the role of RCC1 or Ran⋅GTP in promoting cell proliferation or DDR is not clear. We show that RCC1 overexpression in normal cells increased cellular Ran⋅GTP levels and accelerated the cell cycle and DNA damage repair. As a result, normal cells overexpressing RCC1 evaded DNA damage–induced cell cycle arrest and senescence, mimicking colorectal carcinoma cells with high endogenous RCC1 levels. The RCC1-induced inhibition of senescence required Ran and exportin 1 and involved the activation of importin β–dependent nuclear import of 53BP1, a large NCT cargo. Our results indicate that changes in the activity of the Ran⋅GTP–regulated NCT modulate the rate of the cell cycle and the efficiency of DNA repair. Through the essential role of RCC1 in regulation of cellular Ran⋅GTP levels and NCT, RCC1 expression enables the proliferation of cells that sustain DNA damage. PMID:26864624

  6. Antiproliferative activity of bicyclic benzimidazole nucleosides: synthesis, DNA-binding and cell cycle analysis.

    PubMed

    Sontakke, Vyankat A; Lawande, Pravin P; Kate, Anup N; Khan, Ayesha; Joshi, Rakesh; Kumbhar, Anupa A; Shinde, Vaishali S

    2016-04-26

    An efficient route was developed for synthesis of bicyclic benzimidazole nucleosides from readily available d-glucose. The key reactions were Vörbruggen glycosylation and ring closing metathesis (RCM). Primarily, to understand the mode of DNA binding, we performed a molecular docking study and the binding was found to be in the minor groove region. Based on the proposed binding model, UV-visible and fluorescence spectroscopic techniques using calf thymus DNA (CT-DNA) demonstrated a non-intercalative mode of binding. Antiproliferative activity of nucleosides was tested against MCF-7 and MDA-MB-231 breast cancer cell lines and found to be active at low micromolar concentrations. Compounds and displayed significant antiproliferative activity as compared to and with the reference anticancer drug, doxorubicin. Cell cycle analysis showed that nucleoside induced cell cycle arrest at the S-phase. Confocal microscopy has been performed to validate the induction of cellular apoptosis. Based on these findings, such modified bicyclic benzimidazole nucleosides will make a significant contribution to the development of anticancer drugs. PMID:27074628

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

    PubMed

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

    2016-03-01

    Abnormal localization of tumor suppressor proteins is a common feature of renal cancer. Nuclear export of these tumor suppressor proteins is mediated by chromosome region maintenance-1 (CRM1). Here, we investigated the antitumor eff ects of a novel reversible inhibitor of CRM1 on renal cancer cells. We found that S109 inhibits the CRM1-mediated nuclear export of RanBP1 and reduces protein levels of CRM1. Furthermore, the inhibitory eff ect of S109 on CRM1 is reversible. Our data demonstrated that S109 signifi cantly inhibits proliferation and colony formation of renal cancer cells. Cell cycle assay showed that S109 induced G1-phase arrest, followed by the reduction of Cyclin D1 and increased expression of p53 and p21. We also found that S109 induces nuclear accumulation of tumor suppressor proteins, Foxo1 and p27. Most importantly, mutation of CRM1 at Cys528 position abolished the eff ects of S109. Taken together, our results indicate that CRM1 is a therapeutic target in renal cancer and the novel reversible CRM1 inhibitor S109 can act as a promising candidate for renal cancer therapy. PMID:26937212

  8. Valeric acid induces cell cycle arrest at G1 phase in CHO cell cultures and improves recombinant antibody productivity.

    PubMed

    Park, Jin Hyoung; Noh, Soo Min; Woo, Ju Rang; Kim, Jong Won; Lee, Gyun Min

    2016-03-01

    To find a more effective chemical reagent for improved monoclonal antibody (mAb) production, eight chemical reagents (curcumin, quercein, DL-sulforaphane, thymidine, valeric acid, phenyl butyrate, valproic acid, and lithium chloride) known to induce cell cycle arrest were examined individually as chemical additives to recombinant CHO (rCHO) cell cultures producing mAb. Among these chemical additives, valeric acid showed the best production performance. Valeric acid decreased specific growth rate (μ), but increased culture longevity and specific mAb productivity (qmAb ) in a dose-dependent manner. The beneficial effect of valeric acid on culture longevity and qmAb outweighed its detrimental effect on μ, resulting in 2.9-fold increase in the maximum mAb concentration when 1.5 mM valeric acid was added to the cultures. Furthermore, valeric acid did not negatively affect the mAb quality attributes with regard to aggregation, charge variation, and galactosylation. Unexpectedly, galactosylation of the mAb increased by the 1.5 mM valeric acid addition. Taken together, the results obtained here demonstrate that valeric acid is an effective chemical reagent to increase mAb production in rCHO cells. PMID:26663903

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

    PubMed

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

    2016-04-29

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

  10. A Novel Mutation in DNA Topoisomerase I of Yeast Causes DNA Damage and Rad9-Dependent Cell Cycle Arrest

    PubMed Central

    Levin, N. A.; Bjornsti, M. A.; Fink, G. R.

    1993-01-01

    DNA topoisomerases, enzymes that alter the superhelicity of DNA, have been implicated in such critical cellular functions as transcription, DNA replication, and recombination. In the yeast Saccharomyces cerevisiae, a null mutation in the gene encoding topoisomerase I (TOP1) causes elevated levels of mitotic recombination in the ribosomal DNA (rDNA), but has little effect on growth. We have isolated a missense mutation in TOP1 that causes mitotic hyper-recombination not only in the rDNA, but also at other loci, in addition to causing a number of other unexpected phenotypes. This topoisomerase I mutation (top1-103) causes slow growth, constitutive expression of DNA damage-inducible genes, and inviability in the absence of the double-strand break repair system. Overexpression of top1-103 causes RAD9-dependent cell cycle arrest in G(2). We show that the Top1-103 enzyme nicks DNA in vitro, suggesting that it damages DNA directly. We propose that Top1-103 mimics the action of wild-type topoisomerase I in the presence of the anti-tumor drug, camptothecin. PMID:8385050

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

    PubMed

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

    2014-01-01

    Leukemia is a leading cause of cancer death. Recently, the latexin (Lxn) gene was identified as a potential tumor suppressor in several types of solid tumors and lymphoma, and Lxn expression was found to be absent or downregulated in leukemic cells. Whether Lxn functions as a tumor suppressor in leukemia and what molecular and cellular mechanisms are involved are unknown. In this study, the myeloid leukemogenic FDC-P1 cell line was used as a model system and Lxn was ectopically expressed in these cells. Using the protein pull-down assay and mass spectrometry, ribosomal protein subunit 3 (Rps3) was identified as a novel Lxn binding protein. Ectopic expression of Lxn inhibited FDC-P1 growth in vitro. More surprisingly, Lxn enhanced gamma irradiation-induced DNA damages and induced cell-cycle arrest and massive necrosis, leading to depletion of FDC-P1 cells. Mechanistically, Lxn inhibited the nuclear translocation of Rps3 upon radiation, resulting in abnormal mitotic spindle formation and chromosome instability. Rps3 knockdown increased the radiation sensitivity of FDC-P1, confirming that the mechanism of action of Lxn is mediated by Rps3 pathway. Moreover, Lxn enhanced the cytotoxicity of chemotherapeutic agent, VP-16, on FDC-P1 cells. Our study suggests that Lxn itself not only suppresses leukemic cell growth but also potentiates the cytotoxic effect of radio- and chemotherapy on cancer cells. Lxn could be a novel molecular target that improves the efficacy of anti-cancer therapy. PMID:25341047

  12. Telomere uncapping at the crossroad between cell cycle arrest and carcinogenesis

    PubMed Central

    Gobbini, Elisa; Trovesi, Camilla; Cassani, Corinne; Longhese, Maria Pia

    2014-01-01

    Telomeres are nucleoprotein complexes that protect the natural ends of chromosomes from fusion and degradation and prevent them eliciting a checkpoint response. This protective function, which is called telomere capping, is largely mediated by telomere-binding proteins that suppress checkpoint activation and DNA repair activities. Telomere dysfunction through progressive shortening or removal of capping proteins leads to a checkpoint-mediated block of cell proliferation, which acts as a cancer-suppressor mechanism. However, genetic alterations that inactivate the checkpoint can lead to further telomere erosion and increased genomic instability that, coupled with the activation of mechanisms to restabilize telomeres, can drive the oncogenic process. PMID:27308311

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

    PubMed

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

    2016-01-01

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

  14. Nuclear import, virion incorporation, and cell cycle arrest/differentiation are mediated by distinct functional domains of human immunodeficiency virus type 1 Vpr.

    PubMed Central

    Mahalingam, S; Ayyavoo, V; Patel, M; Kieber-Emmons, T; Weiner, D B

    1997-01-01

    The vpr gene product of human immunodeficiency virus type 1 (HIV-1) is a virion-associated protein that is essential for efficient viral replication in monocytes/macrophages. Vpr is primarily localized in the nucleus when expressed in the absence of other viral proteins. Vpr is packaged efficiently into viral particles through interactions with the p6 domain of the Gag precursor polyprotein p55gag. We developed a panel of expression vectors encoding Vpr molecules mutated in the amino-terminal helical domain, leucine-isoleucine (LR) domain, and carboxy-terminal domain to map the different functional domains and to define the interrelationships between virion incorporation, nuclear localization, cell cycle arrest, and differentiation functions of Vpr. We observed that substitution mutations in the N-terminal domain of Vpr impaired both nuclear localization and virion packaging, suggesting that the helical structure may play a vital role in modulating both of these biological properties. The LR domain was found to be involved in the nuclear localization of Vpr. In contrast, cell cycle arrest appears to be largely controlled by the C-terminal domain of Vpr. The LR and C-terminal domains do not appear to be essential for virion incorporation of Vpr. Interestingly, we found that two Vpr mutants harboring single amino acid substitutions (A30L and G75A) retained the ability to translocate to the nucleus but were impaired in the cell cycle arrest function. In contrast, mutation of Leu68 to Ser resulted in a protein that localizes in the cytoplasm while retaining the ability to arrest host cell proliferation. We speculate that the nuclear localization and cell cycle arrest functions of Vpr are not interrelated and that these functions are mediated by separable putative functional domains of Vpr. PMID:9261351

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

    PubMed Central

    2012-01-01

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

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

    PubMed Central

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

    2016-01-01

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

  17. Remyelinating Oligodendrocyte Precursor Cell miRNAs from the Sfmbt2 Cluster Promote Cell Cycle Arrest and Differentiation

    PubMed Central

    Kuypers, Nicholas J.; Bankston, Andrew N.; Howard, Russell M.; Beare, Jason E.

    2016-01-01

    Oligodendrocyte (OL) loss contributes to the functional deficits underlying diseases with a demyelinating component. Remyelination by oligodendrocyte progenitor cells (OPCs) can restore these deficits. To understand the role that microRNAs (miRNAs) play in remyelination, 2′,3′-cyclic-nucleotide 3′-phosphodiesterase-EGFP+ mice were treated with cuprizone, and OPCs were sorted from the corpus callosum. Microarray analysis revealed that Sfmbt2 family miRNAs decreased during cuprizone treatment. One particular Sfmbt2 miRNA, miR-297c-5p, increased during mouse OPC differentiation in vitro and during callosal development in vivo. When overexpressed in both mouse embryonic fibroblasts and rat OPCs (rOPCs), cell cycle analysis revealed that miR-297c-5p promoted G1/G0 arrest. Additionally, miR-297c-5p transduction increased the number of O1+ rOPCs during differentiation. Luciferase reporter assays confirmed that miR-297c-5p targets cyclin T2 (CCNT2), the regulatory subunit of positive transcription elongation factor b, a complex that inhibits OL maturation. Furthermore, CCNT2-specific knockdown promoted rOPC differentiation while not affecting cell cycle status. Together, these data support a dual role for miR-297c-5p as both a negative regulator of OPC proliferation and a positive regulator of OL maturation via its interaction with CCNT2. SIGNIFICANCE STATEMENT This work describes the role of oligodendrocyte progenitor cell (OPC) microRNAs (miRNAs) during remyelination and development in vivo and differentiation in vitro. This work highlights the importance of miRNAs to OPC biology and describes miR-297c-5p, a novel regulator of OPC function. In addition, we identified CCNT2 as a functional target, thus providing a mechanism by which miR-297c-5p imparts its effects on differentiation. These data are important, given our lack of understanding of OPC miRNA regulatory networks and their potential clinical value. Therefore, efforts to understand the role of miR-297c-5p

  18. Xanthohumol induces apoptosis and S phase cell cycle arrest in A549 non-small cell lung cancer cells

    PubMed Central

    Yong, Wai Kuan; Ho, Yen Fong; Malek, Sri Nurestri Abd

    2015-01-01

    Background: Xanthohumol, a major prenylated chalcone found in female hop plant, Humulus lupulus, was reported to have various chemopreventive and anti-cancer properties. However, its apoptotic effect on human alveolar adenocarcinoma cell line (A549) of non-small cell lung cancer (NSCLC) was unknown. Objective: This study aimed to investigate the effects of xanthohumol on apoptosis in A549 human NSCLC cells. Materials and Methods: A549 cell proliferation was determined by sulforhodamine B assay. Morphological changes of the cells were studied via phase contrast and fluorescent microscopy. Induction of apoptosis was assessed by Annexin-V fluorescein isothiocyanate/propidium iodide (Annexin V-FITC/PI) staining, DNA fragmentation (TUNEL) assay mitochondrial membrane potential assay, cell cycle analysis, and caspase activity studies. Results: Xanthohumol was found to decrease cell proliferation in A549 cells but had relatively low cytotoxicity on normal human lung fibroblast cell line (MRC-5). Typical cellular and nuclear apoptotic features were also observed in A549 cells treated with xanthohumol. Onset of apoptosis in A549 cells was further confirmed by externalization of phosphatidylserine, changes in mitochondrial membrane potential, and DNA fragmentation in the cells after treatment. Xanthohumol induced accumulation of cells in sub G1 and S phase based on cell cycle analysis and also increased the activities of caspase-3, -8, and -9. Conclusion: This work suggests that xanthohumol as an apoptosis inducer, may be a potent therapeutic compound for NSCLC. PMID:26664015

  19. Hyposmotic stress induces cell growth arrest via proteasome activation and cyclin/cyclin-dependent kinase degradation.

    PubMed

    Tao, Guo-Zhong; Rott, Lusijah S; Lowe, Anson W; Omary, M Bishr

    2002-05-31

    Ordered cell cycle progression requires the expression and activation of several cyclins and cyclin-dependent kinases (Cdks). Hyperosmotic stress causes growth arrest possibly via proteasome-mediated degradation of cyclin D1. We studied the effect of hyposmotic conditions on three colonic (Caco2, HRT18, HT29) and two pancreatic (AsPC-1 and PaCa-2) cell lines. Hyposmosis caused reversible cell growth arrest of the five cell lines in a cell cycle-independent fashion, although some cell lines accumulated at the G(1)/S interface. Growth arrest was followed by apoptosis or by formation of multinucleated giant cells, which is consistent with cell cycle catastrophe. Hyposmosis dramatically decreased Cdc2, Cdk2, Cdk4, cyclin B1, and cyclin D3 expression in a time-dependent fashion, in association with an overall decrease in cellular protein synthesis. However, some protein levels remained unaltered, including cyclin E and keratin 8. Selective proteasome inhibition prevented Cdk and cyclin degradation and reversed hyposmotic stress-induced growth arrest, whereas calpain and lysosome enzyme inhibitors had no measurable effect on cell cycle protein degradation. Therefore, hyposmotic stress inhibits cell growth and, depending on the cell type, causes cell cycle catastrophe with or without apoptosis. The growth arrest is due to decreased protein synthesis and proteasome activation, with subsequent degradation of several cyclins and Cdks. PMID:11897780

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

    PubMed Central

    Yu, Chih-Chia; Huang, Hsien-bin; Hung, Shih-Kai; Liao, Hui-Fen; Lee, Ching-Chih; Lin, Hon-Yi; Li, Szu-Chin; Ho, Hsu-Chueh; Hung, Chung-Lin; Su, Yu-Chieh

    2016-01-01

    Background 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. Methods 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. Results 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. Conclusions 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. PMID:27031247

  1. Expression of progesterone receptor B is associated with G0/G1 arrest of the cell cycle and growth inhibition in NIH3T3 cells

    SciTech Connect

    Horiuchi, Shinji; Kato, Kiyoko . E-mail: kkatoh@tsurumi.beppu.kyushu-u.ac.jp; Suga, Shin; Takahashi, Akira; Ueoka, Yousuke; Arima, Takahiro; Nishida, Jun-ichi; Hachisuga, Toru; Kawarabayashi, Tatsuhiko; Wake, Norio

    2005-05-01

    Previously, we found a significant reduction of progesterone receptor B (PR-B) expression levels in the Ras-mediated NIH3T3 cell transformation, and re-expression of exogenous PR-B eliminated the tumorigenic potential. We hypothesized that this reduction is of biological significance in cell transformation. In the present study, we determined the correlation between PR-B expression and cell cycle progression. In synchronized NIH3T3 cells, we found an increase in PR-B protein and p27 CDK inhibitor levels in the G0/G1 phase and a reduction due to redistribution in the S and G2/M phases. The MEK inhibitor or cAMP stimulation arrested NIH3T3 cells in the G0/G1 phase of the cell cycle. The expression of PR-B and p27 CDK inhibitors was up-regulated by treatment with both the MEK inhibitor and cAMP. Treatment of synchronized cells with a PKA inhibitor in the presence of 1% calf serum resulted in a significant reduction in both PR-B and p27 levels. The decrease in the PR-B levels caused by anti-sense oligomers or siRNA corresponded to the reduction in p27 levels. PR-B overexpression by adenovirus infection induced p27 and suppressed cell growth. Finally, we showed that PR-B modulation involved in the regulation of NIH3T3 cell proliferation was independent of nuclear estrogen receptor (ER) activity but dependent on non-genomic ER activity.

  2. Photodynamic hyperthermal therapy with indocyanine green (ICG) induces apoptosis and cell cycle arrest in B16F10 murine melanoma cells.

    PubMed

    Radzi, Rozanaliza; Osaki, Tomohiro; Tsuka, Takeshi; Imagawa, Tomohiro; Minami, Saburo; Nakayama, Yuji; Okamoto, Yoshiharu

    2012-05-01

    We examined the effects of photodynamic hyperthemal therapy (PHT), which is a combination of photodynamic therapy (PDT) and hyperthermia (HT), on the apoptosis and cell cycle progression of murine melanoma B16F10 cells. The percentage of apoptotic cell was determined by flow cytometry using fluorescein isothiocyanate (FITC)-conjugated Annexin V and propidium iodide (PI) double staining. The cell cycle analysis was performed by PI staining with flow cytometry. The expression of cyclins and heat shock protein 70 (Hsp70) were examined by a Western blotting analysis. PHT induces death in B16F10 cells, and PHT-mediated apoptosis occurred acutely and persistently in vitro. Our study demonstrated that PHT using indocyanine green (ICG) and near infrared (NIR) light source induces apoptosis and G0/G1 cell cycle arrest in the B16F10 cells. PMID:22146339

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

    NASA Astrophysics Data System (ADS)

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

    2015-04-01

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

  4. The transduction of His-TAT-p53 fusion protein into the human osteogenic sarcoma cell line (Saos-2) and its influence on cell cycle arrest and apoptosis.

    PubMed

    Jiang, Lei; Ma, Yushu; Wang, Jinzhi; Tao, Xinyi; Wei, Dongzhi

    2008-03-01

    The p53 gene is a tumor suppressor gene. It encodes a nuclear phosphoprotein p53 involved in the regulation of cell cycle arrest and apoptosis to maintain the genomic integrity of the cell. As mutations of p53 gene are found in most human cancers, p53 protein becomes a hot target in the research of anticancer therapy. In the present study, an 11-amino acid domain of TAT protein which has been demonstrated to be able to transduce across cell membranes was fused with p53. The result revealed that the fusion protein His-TAT-p53 accumulated in the nucleus and inhibited the growth of the Saos-2 cells. Besides apoptosis, an increased percentage of G2 phase suggested that the transduction of His-TAT-p53 into cells might be associated with a G2 arrest of cell cycle. PMID:17206471

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

    SciTech Connect

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

    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.

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

    PubMed Central

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

    2012-01-01

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

  7. DNA Damage Response Checkpoint Activation Drives KP1019 Dependent Pre-Anaphase Cell Cycle Delay in S. cerevisiae

    PubMed Central

    Bierle, Lindsey A.; Reich, Kira L.; Taylor, Braden E.; Blatt, Eliot B.; Middleton, Sydney M.; Burke, Shawnecca D.; Stultz, Laura K.; Hanson, Pamela K.; Partridge, Janet F.; Miller, Mary E.

    2015-01-01

    Careful regulation of the cell cycle is required for proper replication, cell division, and DNA repair. DNA damage–including that induced by many anticancer drugs–results in cell cycle delay or arrest, which can allow time for repair of DNA lesions. Although its molecular mechanism of action remains a matter of debate, the anticancer ruthenium complex KP1019 has been shown to bind DNA in biophysical assays and to damage DNA of colorectal and ovarian cancer cells in vitro. KP1019 has also been shown to induce mutations and induce cell cycle arrest in Saccharomyces cerevisiae, suggesting that budding yeast can serve as an appropriate model for characterizing the cellular response to the drug. Here we use a transcriptomic approach to verify that KP1019 induces the DNA damage response (DDR) and find that KP1019 dependent expression of HUG1 requires the Dun1 checkpoint; both consistent with KP1019 DDR in budding yeast. We observe a robust KP1019 dependent delay in cell cycle progression as measured by increase in large budded cells, 2C DNA content, and accumulation of Pds1 which functions to inhibit anaphase. Importantly, we also find that deletion of RAD9, a gene required for the DDR, blocks drug-dependent changes in cell cycle progression, thereby establishing a causal link between the DDR and phenotypes induced by KP1019. Interestingly, yeast treated with KP1019 not only delay in G2/M, but also exhibit abnormal nuclear position, wherein the nucleus spans the bud neck. This morphology correlates with short, misaligned spindles and is dependent on the dynein heavy chain gene DYN1. We find that KP1019 creates an environment where cells respond to DNA damage through nuclear (transcriptional changes) and cytoplasmic (motor protein activity) events. PMID:26375390

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

    SciTech Connect

    Piotrowska, Hanna; Myszkowski, Krzysztof; Ziółkowska, Alicja; Kulcenty, Katarzyna; Wierzchowski, Marcin; Kaczmarek, Mariusz; Murias, Marek; Kwiatkowska-Borowczyk, Eliza; Jodynis-Liebert, Jadwiga

    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.

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

    PubMed Central

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

    2012-01-01

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

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

    PubMed

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

    2012-02-01

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

  11. Thymoquinone, a bioactive component of black caraway seeds, causes G1 phase cell cycle arrest and apoptosis in triple-negative breast cancer cells with mutant p53.

    PubMed

    Sutton, Kimberly M; Greenshields, Anna L; Hoskin, David W

    2014-01-01

    Thymoquinone (TQ) from black caraway seeds has several anticancer activities; however, its effect on triple-negative breast cancer (TNBC) cells that lack functional tumor suppressor p53 is not known. Here, we explored the growth inhibitory effect of TQ on 2 TNBC cell lines with mutant p53. Cell metabolism assays showed that TQ inhibited TNBC cell growth without affecting normal cell growth. Flow cytometric analyses of TQ-treated TNBC cells showed G1 phase cell cycle arrest and apoptosis characterized by the loss of mitochondrial membrane integrity. Western blots of lysates from TQ-treated TNBC cells showed cytochrome c and apoptosis-inducing factor in the cytoplasm, as well as caspase-9 activation consistent with the mitochondrial pathway of apoptosis. Caspase-8 was also activated in TQ-treated TNBC cells, although the mechanism of activation is not clear at this time. Importantly, TQ-induced apoptosis was only partially inhibited by zVAD-fmk, indicating a role for caspase-independent effector molecules. Poly(ADP-ribose) polymerase cleavage and increased γH2AX, as well as reduced Akt phosphorylation and decreased expression of X-linked inhibitor of apoptosis, were evident in TQ-treated cells. Finally, TQ enhanced cisplatin- and docetaxel-induced cytotoxicity. These findings suggest that TQ could be useful in the management of TNBC, even when functional p53 is absent. PMID:24579801

  12. The cranberry flavonoids PAC DP-9 and quercetin aglycone induce cytotoxicity and cell cycle arrest and increase cisplatin sensitivity in ovarian cancer cells.

    PubMed

    Wang, Yifei; Han, Alex; Chen, Eva; Singh, Rakesh K; Chichester, Clinton O; Moore, Richard G; Singh, Ajay P; Vorsa, Nicholi

    2015-05-01

    Cranberry flavonoids (flavonols and flavan-3-ols), in addition to their antioxidant properties, have been shown to possess potential in vitro activity against several cancers. However, the difficulty of isolating cranberry compounds has largely limited anticancer research to crude fractions without well-defined compound composition. In this study, individual cranberry flavonoids were isolated to the highest purity achieved so far using gravity and high performance column chromatography and LC-MS characterization. MTS assay indicated differential cell viability reduction of SKOV-3 and OVCAR-8 ovarian cancer cells treated with individual cranberry flavonoids. Treatment with quercetin aglycone and PAC DP-9, which exhibited the strongest activity, induced apoptosis, led to caspase-3 activation and PARP deactivation, and increased sensitivity to cisplatin. Furthermore, immunofluorescence microscopy and western blot study revealed reduced expression and activation of epidermal growth factor receptor (EGFR) in PAC DP-9 treated SKOV-3 cells. In addition, quercetin aglycone and PAC DP-9 deactivated MAPK-ERK pathway, induced downregulation of cyclin D1, DNA-PK, phospho-histone H3 and upregulation of p21, and arrested cell cycle progression. Overall, this study demonstrates promising in vitro cytotoxic and anti-proliferative properties of two newly characterized cranberry flavonoids, quercetin aglycone and PAC DP-9, against ovarian cancer cells. PMID:25776829

  13. The cranberry flavonoids PAC DP-9 and quercetin aglycone induce cytotoxicity and cell cycle arrest and increase cisplatin sensitivity in ovarian cancer cells

    PubMed Central

    WANG, YIFEI; HAN, ALEX; CHEN, EVA; SINGH, RAKESH K.; CHICHESTER, CLINTON O.; MOORE, RICHARD G.; SINGH, AJAY P.; VORSA, NICHOLI

    2015-01-01

    Cranberry flavonoids (flavonols and flavan-3-ols), in addition to their antioxidant properties, have been shown to possess potential in vitro activity against several cancers. However, the difficulty of isolating cranberry compounds has largely limited anticancer research to crude fractions without well-defined compound composition. In this study, individual cranberry flavonoids were isolated to the highest purity achieved so far using gravity and high performance column chromatography and LC-MS characterization. MTS assay indicated differential cell viability reduction of SKOV-3 and OVCAR-8 ovarian cancer cells treated with individual cranberry flavonoids. Treatment with quercetin aglycone and PAC DP-9, which exhibited the strongest activity, induced apoptosis, led to caspase-3 activation and PARP deactivation, and increased sensitivity to cisplatin. Furthermore, immunofluorescence microscopy and western blot study revealed reduced expression and activation of epidermal growth factor receptor (EGFR) in PAC DP-9 treated SKOV-3 cells. In addition, quercetin aglycone and PAC DP-9 deactivated MAPK-ERK pathway, induced downregulation of cyclin D1, DNA-PK, phosphohistone H3 and upregulation of p21, and arrested cell cycle progression. Overall, this study demonstrates promising in vitro cytotoxic and anti-proliferative properties of two newly characterized cranberry flavonoids, quercetin aglycone and PAC DP-9, against ovarian cancer cells. PMID:25776829

  14. Delphinidin, an Anthocyanidin in Pigmented Fruits and Vegetables, Induces Apoptosis and Cell Cycle Arrest in Human Colon Cancer HCT116 Cells

    PubMed Central

    Yun, Jung-Mi; Afaq, Farrukh; Khan, Naghma; Mukhtar, Hasan

    2010-01-01

    Because of unsatisfactory treatment options for colon cancer, there is a need to develop novel preventive approaches for this malignancy. One such strategy is through chemoprevention by the use of non-toxic dietary substances and botanical products. Delphinidin, an anthocyanidin in pigmented fruits and vegetables, possesses strong antioxidant and anti-inflammatory properties. In the present study, we investigated the antiproliferative and proapoptotic properties of delphinidin in human colon cancer HCT116 cells. We found that treatment of cells with delphinidin (30–240 μM; 48 h) resulted in (i) decrease in cell viability (ii) induction of apoptosis, (iii) cleavage of PARP, (iv) activation of caspases-3, -8, and -9, (v) increase in Bax with a concomitant decrease in Bcl-2 protein, and (vi) G2/M phase cell cycle arrest. NF-κB provides a mechanistic link between inflammation and cancer, and is a major factor controlling the ability of both pre-neoplastic and malignant cells to resist apoptosis-based tumor surveillance mechanisms. We therefore, determined the effect of delphinidin on NF-κB signaling pathway. The immunoblot, ELISA and EMSA analysis demonstrated that the treatment of HCT116 cells with delphinidin resulted in the inhibition of (i) IKKα, (ii) phosphorylation and degradation of IκBα, (iii) phosphorylation of NF-κB/p65 at Ser536, (iv) nuclear translocation of NF-κB/p65, (v) NF-κB/p65 DNA binding activity, and (vi) transcriptional activation of NF-κB. Our results suggest that delphinidin treatment of HCT116 cells suppressed NF-κB pathway, resulting in G2/M phase arrest and apoptosis. We suggest that delphinidin could have potential in inhibiting colon cancer growth. PMID:18729103

  15. SD-208, a Novel Protein Kinase D Inhibitor, Blocks Prostate Cancer Cell Proliferation and Tumor Growth In Vivo by Inducing G2/M Cell Cycle Arrest

    PubMed Central

    Tandon, Manuj; Salamoun, Joseph M.; Carder, Evan J.; Farber, Elisa; Xu, Shuping; Deng, Fan; Tang, Hua; Wipf, Peter; Wang, Q. Jane

    2015-01-01

    Protein kinase D (PKD) has been implicated in many aspects of tumorigenesis and progression, and is an emerging molecular target for the development of anticancer therapy. Despite recent advancement in the development of potent and selective PKD small molecule inhibitors, the availability of in vivo active PKD inhibitors remains sparse. In this study, we describe the discovery of a novel PKD small molecule inhibitor, SD-208, from a targeted kinase inhibitor library screen, and the synthesis of a series of analogs to probe the structure-activity relationship (SAR) vs. PKD1. SD-208 displayed a narrow SAR profile, was an ATP-competitive pan-PKD inhibitor with low nanomolar potency and was cell active. Targeted inhibition of PKD by SD-208 resulted in potent inhibition of cell proliferation, an effect that could be reversed by overexpressed PKD1 or PKD3. SD-208 also blocked prostate cancer cell survival and invasion, and arrested cells in the G2/M phase of the cell cycle. Mechanistically, SD-208-induced G2/M arrest was accompanied by an increase in levels of p21 in DU145 and PC3 cells as well as elevated phosphorylation of Cdc2 and Cdc25C in DU145 cells. Most importantly, SD-208 given orally for 24 days significantly abrogated the growth of PC3 subcutaneous tumor xenografts in nude mice, which was accompanied by reduced proliferation and increased apoptosis and decreased expression of PKD biomarkers including survivin and Bcl-xL. Our study has identified SD-208 as a novel efficacious PKD small molecule inhibitor, demonstrating the therapeutic potential of targeted inhibition of PKD for prostate cancer treatment. PMID:25747583

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

    PubMed

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

    2016-07-01

    Epigenetic modifications play crucial roles in the regulation of chromatin architecture and are involved in cell cycle progression, including mitosis and meiosis. To explore the relationship between epigenetic modifications and the cell cycle, we treated maize (Zea mays) seedlings with six different epigenetic modification-related inhibitors and identified the postsynthetic phase (G2 ) arrest via flow cytometry analysis. Total H4K5ac levels were significantly increased and the distribution of H3S10ph signalling was obviously changed in mitosis under various treatments. Further statistics of the cells in different periods of mitosis confirmed that the cell cycle was arrested at preprophase. Concentrations of hydrogen peroxide were relatively higher in the treated plants and the antioxidant thiourea could negate the influence of the inhibitors. Moreover, all of the treated plants displayed negative results in the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labelling (TUNEL) and γ-H2AX immunostaining assays after exposure for 3 d. Additionally, the expression level of topoisomerase genes in the treated plants was relatively lower than that in the untreated plants. These results suggest that these inhibitors of epigenetic modifications could cause preprophase arrest via reactive oxygen species formation inhibiting the expression of DNA topoisomerase genes, accompanied by changes in the H4K5ac and H3S10ph histone modifications. PMID:27040740

  17. A novel cromakalim analogue induces cell cycle arrest and apoptosis in human cervical carcinoma HeLa cells through the caspase- and mitochondria-dependent pathway.

    PubMed

    Zhang, Xin; Zhao, Jing; Kang, Saeromi; Yi, Myeongjin; You, Song; Shin, Dong-Soo; Kim, Dong-Kyoo

    2011-12-01

    In the present study, a series of seven synthetic croma-kalim analogues were prepared and evaluated for cytotoxic effect on human cervical carcinoma HeLa cells using WST-8 assay. A preliminary screening of these cromakalim analogues showed that 1-[(3S,4R)-4-(2-ethoxy-4-methyl-1H-pyrrol-1-yl)-3-hydroxy- 2,2-dimethylchroman-6-yl-3-phenylurea (compound 6) had the highest cytotoxic effect (IC50 of 138 µM) and significantly inhibited HeLa cell proliferation after 36 h. In an effort to understand the cytotoxic mechanism of compound 6, we examined its effect on apoptosis and cell cycle distribution. Our results showed that compound 6 induced marked changes in apoptotic morphology and significantly increased early apoptosis of HeLa cells after 48 h by using Annexin V-FITC/PI dual staining assay. This apoptotic induction was associated with an increase in Bax expression, a decrease in Bcl-2 expression, release of cytochrome c and subsequent activation of caspase-9 and -3, which indicated that compound 6 induced apoptosis via caspase- and mitochondria-dependent pathway. By DNA content analysis and [3H]thymidine incorporation assay, compound 6 was found to induce an increase in the number of cells in G1 phase, accompanied by a decrease in the S phase to prevent DNA synthesis after 24 h of treatment. In addition, compound 6 caused significant DNA damage, as detected by the alkaline comet assay. Taken together, the data demonstrate that compound 6 induces apoptosis in HeLa cells through caspase- and mitochondria-dependent pathway and this apoptotic effect is associated with cell cycle arrest and DNA damage. These findings provide further understanding of the molecular mechanisms of compound 6 in cervical cancer. PMID:21833470

  18. Combination of Potassium Pentagamavunon-0 and Doxorubicin Induces Apoptosis and Cell Cycle Arrest and Inhibits Metastasis in Breast Cancer Cells.

    PubMed

    Putri, Herwandhani; Jenie, Riris Istighfari; Handayani, Sri; Kastian, Ria Fajarwati; Meiyanto, Edy

    2016-01-01

    A salt compound of a curcumin analogue, potassium pentagamavunon-0 (K PGV-0) has been synthesized to improve solubility of pentagamavunon-0 which has been proven to have anti-proliferative effects on several cancer cells. The purpose of this study was to investigate cytotoxic activity and metastasis inhibition by K PGV- 0 alone and in combination with achemotherapeutic agent, doxorubicin (dox), in breast cancer cells. Based on MTT assay analysis, K PGV-0 showed cytotoxic activity in T47D and 4T1 cell lines with IC50 values of 94.9 μM and 49.0±0.2 μM, respectively. In general, K PGV-0+dox demonstrated synergistic effects and decreased cell viability up to 84.7% in T47D cells and 62.6% in 4T1 cells. Cell cycle modulation and apoptosis induction were examined by flow cytometry. K PGV-0 and K PGV-0+dox caused cell accumulation in G2/M phase and apoptosis induction. Regarding cancer metastasis, while K PGV-0 alone did not show any inhibition of 4T1 cell migration, K PGV-0+dox exerted inhibition. K PGV-0 and its combination with dox inhibited the activity of MMP-9 which has a pivotal role in extracellular matrix degradation. These results show that a combination of K PGV-0 and doxorubicin inhibits cancer cell growth through cell cycling, apoptosis induction, and inhibition of cell migration and MMP-9 activity. Therefore, K PGV-0 may have potential for development as a co-chemotherapeutic agent. PMID:27268651

  19. CARI III inhibits tumor growth in a melanoma-bearing mouse model through induction of G0/G1 cell cycle arrest.

    PubMed

    Park, Hye-Jin

    2014-01-01

    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. PMID:25221864

  20. Dipyrithione induces cell-cycle arrest and apoptosis in four cancer cell lines in vitro and inhibits tumor growth in a mouse model

    PubMed Central

    2013-01-01

    Background Dipyrithione (PTS2) is widely used as a bactericide and fungicide. Here, we investigated whether PTS2 has broad-spectrum antitumor activity by studying its cytotoxicity and proapoptotic effects in four cancer cell lines. Methods We used MTT assays and trypan blue staining to test the viability of cancer cell lines. Hoechst 33258 and DAPI staining were used to observe cell apoptosis. Cell-cycle percentages were analyzed by flow cytometry. Apoptosis was assayed using caspase-3 and poly (ADP-ribose) polymerase (PARP) combined with Western blotting. Student’s t-test was used for statistical analysis. Results PTS2 inhibited proliferation in four cancer cell lines in a dose-dependent manner. Treated cells showed shrinkage, irregular fragments, condensed and dispersed blue fluorescent particles compared with control cells. PTS2 induced cycle-arrest and death. Cleavage of caspase-9, caspase-3, and PARP were detected in PTS2-treated cells. Antitumor activity of PTS2 was more effective against widely used cancer drugs and its precursor. Conclusions PTS2 appears to have novel cytotoxicity and potent broad-spectrum antitumor activity, which suggests its potential as the basis of an anticancer drug. PMID:24139500

  1. Sulforaphane induced cell cycle arrest in the G2/M phase via the blockade of cyclin B1/CDC2 in human ovarian cancer cells

    PubMed Central

    2013-01-01

    Background Malignant tumors are the single most common cause of death and the mortality rate of ovarian cancer is the highest among gynecological disorders. The excision of benign tumors is generally followed by complete recovery; however, the activity of cancer cells often results in rapid proliferation even after the tumor has been excised completely. Thus, clinical treatment must be supplemented by auxiliary chemotherapy or radiotherapy. Sulforaphane (SFN) is an extract from the mustard family recognized for its anti-oxidation abilities, phase 2 enzyme induction, and anti-tumor activity. Methods This study investigated the cell cycle arrest in G2/M by SFN and the expression of cyclin B1, Cdc2, and the cyclin B1/CDC2 complex in PA-1 cells using western blotting and co-IP western blotting. Results This study investigated the anticancer effects of dietary isothiocyanate SFN on ovarian cancer, using cancer cells line PA-1. SFN-treated cells accumulated in metaphase by CDC2 down-regulation and dissociation of the cyclin B1/CDC2 complex. Conclusion Our findings suggest that, in addition to the known effects on cancer prevention, SFN may also provide antitumor activity in established ovarian cancer. PMID:23799914

  2. Human T-cell leukemia virus type 1 infection leads to arrest in the G1 phase of the cell cycle.

    PubMed

    Liu, Meihong; Yang, Liangpeng; Zhang, Ling; Liu, Baoying; Merling, Randall; Xia, Zheng; Giam, Chou-Zen

    2008-09-01

    Infection by the human T-cell leukemia virus type 1 (HTLV-1) is thought to cause dysregulated T-cell proliferation, which in turn leads to adult T-cell leukemia/lymphoma. Early cellular changes after HTLV-1 infection have been difficult to study due to the poorly infectious nature of HTLV-1 and the need for cell-to-cell contact for HTLV-1 transmission. Using a series of reporter systems, we show that HeLa cells cease proliferation within one or two division cycles after infection by HTLV-1 or transduction of the HTLV-1 tax gene. HTLV-1-infected HeLa cells, like their tax-transduced counterparts, expressed high levels of p21(CIP1/WAF1) and p27(KIP1), developed mitotic abnormalities, and became arrested in G(1) in senescence. In contrast, cells of a human osteosarcoma lineage (HOS) continued to divide after HTLV-1 infection or Tax expression, albeit at a reduced growth rate and with mitotic aberrations. Unique to HOS cells is the dramatic reduction of p21(CIP1/WAF1) and p27(KIP1) expression, which is in part associated with the constitutive activation of the phosphatidylinositol-3-kinase (PI3K)-protein kinase B (Akt) pathway. The loss of p21(CIP1/WAF1) and p27(KIP1) in HOS cells apparently allows HTLV-1- and Tax-induced G(1) arrest to be bypassed. Finally, HTLV-1 infection and Tax expression also cause human SupT1 T cells to arrest in the G(1) phase of the cell cycle. These results suggest that productive HTLV-1 infection ordinarily leads to Tax-mediated G(1) arrest. However, T cells containing somatic mutations that inactivate p21(CIP1/WAF1) and p27(KIP1) may continue to proliferate after HTLV-1 infection and Tax expression. These infected cells can expand clonally, accumulate additional chromosomal abnormalities, and progress to cancer. PMID:18596104

  3. Disruption of G1-phase phospholipid turnover by inhibition of Ca2+-independent phospholipase A2 induces a p53-dependent cell-cycle arrest in G1 phase.

    PubMed

    Zhang, Xu Hannah; Zhao, Chunying; Seleznev, Konstantin; Song, Keying; Manfredi, James J; Ma, Zhongmin Alex

    2006-03-15

    The G1 phase of the cell cycle is characterized by a high rate of membrane phospholipid turnover. Cells regulate this turnover by coordinating the opposing actions of CTP:phosphocholine cytidylyltransferase and the group VI Ca2+-independent phospholipase A2 (iPLA2). However, little is known about how such turnover affects cell-cycle progression. Here, we show that G1-phase phospholipid turnover is essential for cell proliferation. Specific inhibition of iPLA2 arrested cells in the G1 phase of the cell cycle. This G1-phase arrest was associated with marked upregulation of the tumour suppressor p53 and the expression of cyclin-dependent kinase inhibitor p21cip1. Inactivation of iPLA2 failed to arrest p53-deficient HCT cells in the G1 phase and caused massive apoptosis of p21-deficient HCT cells, suggesting that this G1-phase arrest requires activation of p53 and expression of p21cip1. Furthermore, downregulation of p53 by siRNA in p21-deficient HCT cells reduced the cell death, indicating that inhibition of iPLA2 induced p53-dependent apoptosis in the absence of p21cip1. Thus, our study reveals hitherto unrecognized cooperation between p53 and iPLA2 to monitor membrane-phospholipid turnover in G1 phase. Disrupting the G1-phase phospholipid turnover by inhibition of iPLA2 activates the p53-p21cip1 checkpoint mechanism, thereby blocking the entry of G1-phase cells into S phase. PMID:16492706

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

    SciTech Connect

    Wang, Huiling; Li, Ridong; Li, Li; Ge, Zemei; Zhou, Rouli; Li, Runtao

    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.

  5. Cell cycle effect on the activity of deoxynucleoside analogue metabolising enzymes

    SciTech Connect

    Fyrberg, Anna; Albertioni, Freidoun; Lotfi, Kourosh . E-mail: koulo@imv.liu.se

    2007-06-15

    Deoxynucleoside analogues (dNAs) are cytotoxic towards both replicating and indolent malignancies. The impact of fluctuations in the metabolism of dNAs in relation to cell cycle could have strong implications regarding the activity of dNAs. Deoxycytidine kinase (dCK) and deoxyguanosine kinase (dGK) are important enzymes for phosphorylation/activation of dNAs. These drugs can be dephosphorylated/deactivated by 5'-nucleotidases (5'-NTs) and elevated activities of 5'-NTs and decreased dCK and/or dGK activities represent resistance mechanisms towards dNAs. The activities of dCK, dGK, and three 5'-NTs were investigated in four human leukemic cell lines in relationship to cell cycle progression and cytotoxicity of dNAs. Synchronization of cell cultures to arrest in G0/G1 by serum-deprivation was performed followed by serum-supplementation for cell cycle progression. The activities of dCK and dGK increased up to 3-fold in CEM, HL60, and MOLT-4 cells as they started to proliferate, while the activity of cytosolic nucleotidase I was reduced in proliferating cells. CEM, HL60, and MOLT-4 cells were also more sensitive to cladribine, cytarabine, 9-{beta}-D-arabinofuranosylguanine and clofarabine than K562 cells which demonstrated lower levels and less alteration of these enzymes and were least susceptible to the cytotoxic effects of most dNAs. The results suggest that, in the cell lines studied, the proliferation process is associated with a general shift in the direction of activation of dNAs by inducing activities of dCK/dGK and reducing the activity of cN-I which is favourable for the cytotoxic effects of cladribine, cytarabine and, 9-{beta}-D-arabinofuranosylguanine. These results emphasize the importance of cellular proliferation and dNA metabolism by both phosphorylation and dephosphorylation for susceptibility to dNAs. It underscores the need to understand the mechanisms of action and resistance to dNAs in order to increase efficacy of dNAs treatment by new rational.

  6. The flavonoid quercetin transiently inhibits the activity of taxol and nocodazole through interference with the cell cycle

    PubMed Central

    Samuel, Temesgen; Fadlalla, Khalda; Turner, Timothy; Yehualaeshet, Teshome E.

    2010-01-01

    Quercetin is a flavonoid with anticancer properties. In this study, we examined the effects of quercetin on cell cycle, viability and proliferation of cancer cells, either singly or in combination with the microtubule-targeting drugs taxol and nocodazole. Although quercetin induced cell death in a dose dependent manner, 12.5-50μM quercetin inhibited the activity of both taxol and nocodazole to induce G2/M arrest in various cell lines. Quercetin also partially restored drug-induced loss in viability of treated cells for up to 72 hours. This antagonism of microtubule-targeting drugs was accompanied by a delay in cell cycle progression and inhibition of the buildup of cyclin-B1 at the microtubule organizing center of treated cells. However, quercetin did not inhibit the microtubule targeting of taxol or nocodazole. Despite the short-term protection of cells by quercetin, colony formation and clonogenicity of HCT116 cells were still suppressed by quercetin or quercetin-taxol combination. The status of cell adherence to growth matrix was critical in determining the sensitivity of HCT116 cells to quercetin. We conclude that while long-term exposure of cancer cells to quercetin may prevent cell proliferation and survival, the interference of quercetin with cell cycle progression diminishes the efficacy of microtubule-targeting drugs to arrest cells at G2/M. PMID:21058190

  7. Aspafilioside B induces G2/M cell cycle arrest and apoptosis by up-regulating H-Ras and N-Ras via ERK and p38 MAPK signaling pathways in human hepatoma HepG2 cells.

    PubMed

    Liu, Wei; Ning, Rui; Chen, Rui-Ni; Huang, Xue-Feng; Dai, Qin-Sheng; Hu, Jin-Hua; Wang, Yu-Wen; Wu, Li-Li; Xiong, Jing; Hu, Gang; Guo, Qing-Long; Yang, Jian; Wang, Hao

    2016-05-01

    We recently establish that aspafilioside B, a steroidal saponin extracted from Asparagus filicinus, is an active cytotoxic component. However, its antitumor activity is till unknown. In this study, the anticancer effect of aspafilioside B against HCC cells and the underlying mechanisms were investigated. Our results showed that aspafilioside B inhibited the growth and proliferation of HCC cell lines. Further study revealed that aspafilioside B could significantly induce G2 phase cell cycle arrest and apoptosis, accompanying the accumulation of reactive oxygen species (ROS), but blocking ROS generation with N-acetyl-l-cysteine (NAC) could not prevent G2/M arrest and apoptosis. Additionally, treatment with aspafilioside B induced phosphorylation of extracellular signal-regulated kinase (ERK) and p38 MAP kinase. Moreover, both ERK inhibitor PD98059 and p38 inhibitor SB203580 almost abolished the G2/M phase arrest and apoptosis induced by aspafilioside B, and reversed the expression of cell cycle- and apoptosis-related proteins. We also found that aspafilioside B treatment increased both Ras and Raf activation, and transfection of cells with H-Ras and N-Ras shRNA almost attenuated aspafilioside B-induced G2 phase arrest and apoptosis as well as the ERK and p38 activation. Finally, in vivo, aspafilioside B suppressed tumor growth in mouse xenograft models, and the mechanism was the same as in vitro study. Collectively, these findings indicated that aspafilioside B may up-regulate H-Ras and N-Ras, causing c-Raf phosphorylation, and lead to ERK and p38 activation, which consequently induced the G2 phase arrest and apoptosis. This study provides the evidence that aspafilioside B is a promising therapeutic agent against HCC. PMID:25683703

  8. Apoptosis in T cell acute lymphoblastic leukemia cells after cell cycle arrest induced by pharmacological inhibition of notch signaling.

    PubMed

    Lewis, Huw D; Leveridge, Matthew; Strack, Peter R; Haldon, Christine D; O'neil, Jennifer; Kim, Hellen; Madin, Andrew; Hannam, Joanne C; Look, A Thomas; Kohl, Nancy; Draetta, Giulio; Harrison, Timothy; Kerby, Julie A; Shearman, Mark S; Beher, Dirk

    2007-02-01

    In this report, inhibitors of the gamma-secretase enzyme have been exploited to characterize the antiproliferative relationship between target inhibition and cellular responses in Notch-dependent human T cell acute lymphoblastic leukemia (T-ALL) cell lines. Inhibition of gamma-secretase led to decreased Notch signaling, measured by endogenous NOTCH intracellular domain (NICD) formation, and was associated with decreased cell viability. Flow cytometry revealed that decreased cell viability resulted from a G(0)/G(1) cell cycle block, which correlated strongly to the induction of apoptosis. These effects associated with inhibitor treatment were rescued by exogenous expression of NICD and were not mirrored when a markedly less active enantiomer was used, demonstrating the gamma-secretase dependency and specificity of these responses. Together, these data strengthen the rationale for using gamma-secretase inhibitors therapeutically and suggest that programmed cell death may contribute to reduction of tumor burden in the clinic. PMID:17317574

  9. Harmine induces cell cycle arrest and mitochondrial pathway-mediated cellular apoptosis in SW620 cells via inhibition of the Akt and ERK signaling pathways.

    PubMed

    Liu, Jiming; Li, Qiang; Liu, Zhilong; Lin, Liuming; Zhang, Xiangqiang; Cao, Mingrong; Jiang, Jianwei

    2016-06-01

    Harmine, a β-carboline alkaloid isolated from the seeds of Peganum harmala, possesses both antitumor and anti‑nociceptive effects and inhibits human DNA topoisomerase. However, no detailed data are available concerning the mechanisms of harmine in human colorectal carcinoma SW620 cells. In the present study, we demonstrated that harmine inhibited the proliferation of SW620 cells in a dose-dependent manner using MTT and clone formation assays, and the IC50 value of harmine on the growth inhibition of SW620 cells for 48 h was 5.13 µg/ml. PI staining showed that harmine altered the cell cycle distribution by decreasing the proportion of cells in the G0-G1 phase and increasing the proportion in the S and G2-M phase. The expression level of cyclin D1 was decreased, while the expression of cyclin A, E2 and B1, CDK1/cdc2, Myt-1 and p-cdc2 (Tyr15) were increased, which was in accordance with the S and G2/M phase arrest. Hoechst 33258 staining revealed nuclear fragmentation, chromosomal condensation and cell shrinkage in the SW620 cells treated with harmine. Flow cytometry revealed that the percentage of apoptotic sub-G1 cells increased from 7.19 to 26.58%, while in the control group, sub-G1 cells only increased from 1.53 to 1.60%. Furthermore, early and late apoptotic cells were increased from 11.96 to 26.38% when incubated with the indicated concentration of harmine for 48 h, while in the control group, <8% of cells underwent apoptosis. JC-1 staining revealed that harmine decreased mitochondrial transmembrane potential (ΔΨm). The apoptosis of SW620 cells was also detected by western blot analysis, showing caspase-3 and -9, and PARP activation; the downregulation of Bcl-2, Mcl-1, Bcl-xL; and the upregulation of Bax. The expression of p-ERK, p-Akt (Ser473) and p-Akt (Thr308) was inhibited, and phosphorylation of downstream targets of Akt, such as p-FoxO3a and p-GSK‑3β were also attenuated. In conclusion, harmine induces cell cycle arrest and

  10. Molecular response to phototoxic stress of UVB-irradiated ketoprofen through arresting cell cycle in G2/M phase and inducing apoptosis

    SciTech Connect

    Liu Shicheng Mizu, Hideo; Yamauchi, Hitoshi

    2007-12-21

    The phototoxicity of ketoprofen (KP), a non-steroidal anti-inflammatory drug, has recently attracted considerable attention, because it is photolabile and undergoes degradation when irradiated by sunlight to induce various skin diseases. The present study shows that combination of UVB irradiation with KP induced the cytotoxicity and suppressed DNA synthesis in HaCaT cells in a concentration-dependent manner. UVB-irradiated KP inhibited the cell growth and induced G2/M cell cycle arrest by modulating the levels of cdc2, cyclin B1, Chk1, Tyr15-phosphorylated cdc2 and p21. It also provoked a striking accumulation of cyclin B1-cdc2-p21 complexes, concomitantly with an increase in the levels of Tyr15-phosphorylated cdc2 and p21 protein. The presence of KP accentuated the apoptotic response to UVB radiation in HaCaT cells as evidenced by DAPI staining. The apoptotic process was associated with activation of caspase-9, caspase-3 and cleavage of PARP, and this activation could be prevented by a specific caspase-3 inhibitor. Taken together, our results suggest that KP-photoinduced apoptosis may be a useful approach to reduce or prevent skin carcinogenesis.

  11. Limb-bud and Heart (LBH) functions as a tumor suppressor of nasopharyngeal carcinoma by inducing G1/S cell cycle arrest.

    PubMed

    Liu, Qicai; Guan, Xiaoying; Lv, Jingli; Li, Xiaoyan; Wang, Yingfeng; Li, Li

    2015-01-01

    Epstein-Barr virus-encoded latent membrane protein-1 (LMP1) plays a fundamental role in the malignant transformation of nasopharyngeal carcinoma (NPC), although the mechanism is not well understood. Here, we showed that Limb-bud and Heart (LBH) is considerably downregulated in patient NPC tissues. The expression of LBH in biopsies of 40 consecutive NPC patients devoid of initial distant metastasis and treated according to consistent guidelines was also analyzed, and we found the LBH expression level was correlated with some of clinicopathological features, disease-specific survival (DSS), distant metastasis-free survival (DMFS). We further determined that LBH normally induces NPC cell cycle arrest at the G1/S transition, and LBH can suppress the growth of transplanted NPC tumors in vivo by downregulating LMP1-mediated NF-κB transcriptional activity. Transforming growth factor-beta 1 (TGF-β1) normally protects against tumor development by suppressing cell proliferation, but NPC cells acquire resistance to TGF-β1-mediated inhibition. We found that TGF-β1 inhibits NF-κB transcriptional activity and nasopharyngeal epithelial cell proliferation through upregulating LBH expression. These data reveal a previously unknown NPC transformation mechanism and provide a new concept and treatment strategy for LMP1-driven oncogenesis in NPC. PMID:25557837

  12. Xerophilusin B induces cell cycle arrest and apoptosis in esophageal squamous cell carcinoma cells and does not cause toxicity in nude mice.

    PubMed

    Yao, Ran; Chen, Zhaoli; Zhou, Chengcheng; Luo, Mei; Shi, Xuejiao; Li, Jiagen; Gao, Yibo; Zhou, Fang; Pu, Jianxin; Sun, Handong; He, Jie

    2015-01-23

    Esophageal cancer is the eighth most common cancer in the world and ranks as the sixth leading cause of cancer-related mortality. Esophageal cancer has a poor prognosis partially due to its low sensitivity to chemotherapy agents, and the development of new therapeutic agents is urgently needed. Here, the antitumor activity of a natural ent-kaurane diterpenoid, xerophilusin B (1), which was isolated from Isodon xerophilus, a perennial herb frequently used in Chinese folk medicine for tumor treatment, was investigated. Compound 1 exhibited antiproliferative effects against esophageal squamous cell carcinoma (ESCC) cell lines in a time- and dose-dependent manner with lower toxicity against normal human and murine cell lines. In vivo studies demonstrated that 1 inhibited tumor growth of a human esophageal tumor xenograft in BALB/c nude mice without significant secondary adverse effects, indicating its safety in treating ESCC. Furthermore, 1 induced G2/M cell cycle arrest and promoted apoptosis through mitochondrial cytochrome c-dependent activation of the caspase-9 and caspase-3 cascade pathway in ESCC cell lines. In conclusion, the observations herein reported showed that 1 is a potential chemotherapeutic agent for ESCC and merits further preclinical and clinical investigation for cancer drug development. PMID:25555195

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

    PubMed

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

    2014-01-01

    Breast cancers that are estrogen receptor (ER) negative or are ER negative with ErbB2/HER-2 overexpression have a poor prognosis, which emphasizes the importance of developing compounds for preventing breast cancer. Nexrutine, an herbal extract from the plant Phellodendron amurense, has been used for centuries in Asian medicine to treat inflammation, gastroenteritis, abdominal pain, and diarrhea. In this study we investigated the anticancer effects of Nexrutine on ER negative breast cancer cell lines that are positive or negative for HER-2. Nexrutine decreased the activities of 2 potential targets of breast cancer, cyclooxygenase (COX)-2, and peroxisome proliferators activated receptor gamma (PPARγ). The antiinflammatory effects of Nexrutine were evident with decreased prostaglandin (PG)E2 production, protein expression of microsomal PGE2 synthase (mPGES), and PPARγ. Nexrutine decreased cell survival and induced a G1 cell cycle arrest in SkBr3 and MDA-MB 231 cells, which were associated with reduced protein expression of Cyclin D1 and cdk2 along with increased protein expression of p21 and p27. The growth-inhibitory effect of Nexrutine was associated with apoptosis in SkBr3 cells and autophagy in MDA-MB231 cells. Based on these findings, we propose that Nexrutine may provide a novel approach for protection against breast cancer. PMID:24206214

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

    SciTech Connect

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

    2015-01-02

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

  15. Depletion of Aurora A leads to upregulation of FoxO1 to induce cell cycle arrest in hepatocellular carcinoma cells

    PubMed Central

    Lee, Sun-Young; Lee, Gong Rak; Woo, Dong-Hyuk; Park, Neung Hwa; Cha, Hee Jeong; Moon, Yong-Hwan; Han, In-Seob

    2013-01-01

    Aurora A kinase has drawn considerable attention as a therapeutic target for cancer therapy. However, the underlying molecular and cellular mechanisms of the anticancer effects of Aurora A kinase inhibition are still not fully understood. Herein, we show that depletion of Aurora A kinase by RNA interference (RNAi) in hepatocellular carcinoma (HCC) cells upregulated FoxO1 in a p53-dependent manner, which induces cell cycle arrest. Introduction of an RNAi-resistant Aurora A kinase into Aurora A-knockdown cells resulted in downregulation of FoxO1 expression and rescued proliferation. In addition, silencing of FoxO1 in Aurora A-knockdown cells allowed the cells to exit cytostatic arrest, which, in turn, led to massive cell death. Our results suggest that FoxO1 is responsible for growth arrest at the G2/M phase that is induced by Aurora A kinase inhibition. PMID:23255113

  16. Butein inhibits cell proliferation and induces cell cycle arrest in acute lymphoblastic leukemia via FOXO3a/p27kip1 pathway

    PubMed Central

    Wang, Li-Na; Tian, Yun; Shi, Dingbo; Wang, Jingshu; Qin, Ge; Li, Anchuan; Liang, Yan-Ni; Zhou, Huan-Juan; Ke, Zhi-Yong; Huang, Wenlin; Deng, Wuguo; Luo, Xue-Qun

    2016-01-01

    Acute lymphoblastic leukemia (ALL) is a common hematological malignancy characterized by the uncontrolled proliferation of leukemia cells in children. Discovering and developing effective chemotherapeutic drugs are needed for ALL. In this study, we investigated the anti-leukemic activity of butein and its action mechanisms in ALL. Butein was found to significantly suppress the cellular proliferation of ALL cell lines and primary ALL blasts in a dose-dependent manner. It also induced cell cycle arrest by decreasing the expression of cyclin E and CDK2. We also found that butein promoted nuclear Forkhead Class box O3a (FOXO3a) localization, enhanced the binding of FOXO3a on the p27kip1 gene promoter and then increased the expression of p27kip1. Moreover, we showed that FOXO3a knockdown significantly decreased the proliferation inhibition by butein, whereas overexpression of FOXO3a enhanced the butein-mediated proliferation inhibition. However, overexpression of FOXO3a mutation (C-terminally truncated FOXO3a DNA-binding domain) decreased the proliferation inhibition by butein through decreasing the expression of p27kip1. Our results therefore demonstrate the therapeutic potential of butein for ALL via FOXO3a/p27kip1 pathway. PMID:26919107

  17. Flavonoid-enriched apple fraction AF4 induces cell cycle arrest, DNA topoisomerase II inhibition, and apoptosis in human liver cancer HepG2 cells.

    PubMed

    Sudan, Sudhanshu; Rupasinghe, H P Vasantha

    2014-01-01

    Apples are a major source of dietary phytochemicals such as flavonoids in the Western diet. Here we report anticancer properties and possible mechanism of action of apple flavonoid-enriched fraction (AF4) isolated from the peels of Northern Spy apples in human hepatocellular carcinoma cells, HepG2. Treatment with AF4 induced cell growth inhibition in HepG2 cells in time- and dose-dependent manner. Concentration of 50 μg/ml (50 μg total monomeric polyphenols/ml) AF4 was sufficient to induce a significant reduction in cell viability within 6 h of treatment (92%, P < 0.05) but had very low toxicity (minimum 4% to maximum 16%) on primary liver and lung cells, which was significantly lower than currently prescribed chemotherapy drug Sorafenib (minimum 29% to maximum 49%, P < 0.05). AF4 induced apoptosis in HepG2 cells within 6 h of treatment via activation of caspase-3. Cell cycle analysis via flow-cytometer showed that AF4 induced G2/M phase arrest. Further, results showed that AF4 acts as a strong DNA topoisomerase II catalytic inhibitor, which may be a plausible reason to drive the cells to apoptosis. Overall, our data suggests that AF4 possesses a significantly stronger antiproliferative and specific action than Sorafenib in vitro and is a potential natural chemotherapy agent for treatment of liver cancer. PMID:25256427

  18. Dietary Fatty Acids from Leaves of Clerodendrum Volubile Induce Cell Cycle Arrest, Downregulate Matrix Metalloproteinase-9 Expression, and Modulate Redox Status in Human Breast Cancer.

    PubMed

    Erukainure, Ochuko L; Zaruwa, Moses Z; Choudhary, M Iqbal; Naqvi, S Asma; Ashraf, Nadia; Hafizur, Rahman M; Muhammad, Aliyu; Ebuehi, Osaretin A T; Elemo, Gloria N

    2016-01-01

    The antiproliferative effect of the fatty acid components of Clerodendrum volubile leaves as well as its antioxidant effect on MCF-7 and MDA-MB-231 human breast cancer cell lines were investigated. Fatty acids extracted from C. volubile leaf oil were subjected to gas chromatography mass spectrometry (GCMS) analysis. The cells were cultured and treated with the fatty acids for 48 h, after which the antiproliferation effect was ascertained via MTT assay and cell viability analysis using BD fluorescence activated cells sorting (FACS) Calibur. Cell cycle was analyzed by flow cytometry on FACS Calibur. Western blotting was used in determining expression of proteins in the cell lines. The treated cell lines were assessed for reduced glutathione level, catalase, superoxide dismutase, and lipid peroxidation. The fatty acids significantly inhibited cell proliferation, arrested G0/G1 phase, downregulated the expression of MMP-9, and attenuated oxidative stress in of MCF-7 cell lines but had little or no effect on MDA-MB-231 cell lines. These results indicate the therapeutic potential of the fatty acids components of the leaves of C. volubile on human breast cancer, which may be explored further in drug development. PMID:27043182

  19. Crude extract of Rheum palmatum L. Induces cell cycle arrest S phase and apoptosis through mitochondrial-dependent pathways in U-2 OS human osteosarcoma cells.

    PubMed

    Lin, Chin-Chung; Lee, Ming-Huei; Lin, Ju-Hwa; Lin, Meng-Liang; Chueh, Fu-Shin; Yu, Chien-Chih; Lin, Jing-Pin; Chou, Yu-Cheng; Hsu, Shu-Chun; Chung, Jing-Gung

    2016-08-01

    Cancer is the second cause of death in children. Osteosarcoma is the most common primary malignancy of solid bone cancer primarily affecting adolescents and young adults. In the Chinese population, the crude extract of Rheum palmatum L. (CERP) has been used for treating different diseases, including SARS, rheumatoid arthritis, coxsackievirus B3, and human colon cancer cell, pancreatic cancer. There are no reports on CERP and human osteosarcoma cells. The present study examined effects of CERP on cytotoxicity including cell cycle distribution and cell death (apoptosis) in U-2 OS human osteosarcoma cells. CERP significantly induced S phase arrest in U-2 OS cells in a dose-dependent. CERP produced DNA damage and DNA condensation. Other effects of CERP were stimulation of ROS and Ca(2+) , mitochondria impairment, and activation of caspase-3, -8, and -9. CERP increased the levels of Bax, Bak, Bad, cyclin B, Fas, PARP, GRP78, GADD153, AIF, Endo G, Calpain-2, p21, and p27, but decreased the levels of Bcl-2, BCL-X, XIAP, Akt, CDC25A, CDK2, Cyclin A, and Cyclin E of U-2 OS cells. It was also observed that CERP promoted the expression of AIF, Endo G, GADD153, and cytochrome c. These results indicate that CERP has anticancer effects in vitro and provide the foundation for in vivo studies of animal models of osteosarcoma. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 957-969, 2016. PMID:25689151

  20. Two new isoquinoline alkaloids from Scolopendra subspinipes mutilans induce cell cycle arrest and apoptosis in human glioma cancer U87 cells.

    PubMed

    Ding, Dan; Guo, Ya-Ru; Wu, Rui-Ling; Qi, Wei-Yan; Xu, Han-Mei

    2016-04-01

    Two new isoquinoline alkaloids 1-2 and seven known compounds 3-9 were isolated from the ethanol extract of centipede Scolopendra subspinipes mutilans L. Koch. The structures were elucidated by a combination of spectroscopic analyses including 1D and 2D NMR, and HRESIMS. Compounds 1-2 exhibited good cytotoxicity with IC50 values ranging from 1.19 to 31.28μM against six human cancer cell lines and low cytotoxicity against human normal liver L-02 cell lines, suggesting that compounds 1-2 had high specific cytotoxicity on human cancer cell lines. Further analyses showed that compounds 1-2 inhibited U87 cells proliferation by arresting cell cycle progress at G0/G1 phase and inducing apoptosis through loss of mitochondrial membrane potential (MMP), activation of caspase 9/3 and down-regulation of the Bcl-2/Bax protein ratio. The results suggest that compounds 1-2 induce apoptosis in U87 cells through the mitochondria apoptosis pathway, and they deserve further research as potential anti-glioma cancer agents. PMID:26947248